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RCPA Part 1 > Clinical > Flashcards

Clinical Flashcards

1
Q

Causes of primary ovarian insufficiency (POI)

A
  • Idiopathic
  • Turner syndrome
  • Premutations for Fragile X
  • Autoimmune (may be part of polyglandular syndrome)
  • Toxicity to ovaries - chemoTx, RadioTx
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2
Q

Physiological stimulators of GH secretion

A

Hypoglycaemia
Fasting
Starvation
Exercise
Stress and trauma
Sepsis
Insulin

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3
Q

GH secretion is inhibited by..

A

Hyperglycaemia
Increase in free fatty acids in blood

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4
Q

Hereditary causes of methaemoglobinaemia?

A

HbM

Cytochrome b5 reductase deficiency

G6PD deficiency (however minor role compared to cytochrome b5 reductase)

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5
Q

Acquired causes of methaemoglobinaemia?

A

Medications e.g. Benzocaine; dapsone; primaquine
Chemical agents e.g. chlorobenzene; silver nitrate
Nitrate containing foods

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6
Q

What clinical signs/findings lead to a diagnosis of methaemoglobinaemia?

A

Cyanosis unresponsive to oxygen
Chocolate coloured blood
Saturation gap of >5% (difference between pulse oximeter and multiwavelength oximeter)

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7
Q

Methods to confirm presence of increased Met-Hb?

A

Multiwavelength oximeter on blood gas instrument

Evelyn-Malloy test (add cyanide to bind with Met-Hb and amount of absorption elimination is proportional to Met-Hb)

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8
Q

What factors other than GnRH regulate FSH secretion?

A
  • Inhibin - inhibits FSH secretion
  • Activin - activates FSH secretion
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9
Q

Causes of decreased IGF-1

A
  • GH deficiency
  • Malnutrition
  • Liver failure
  • Renal failure
  • Hypothyroidism
  • Poorly controlled DM
  • Severe infection
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10
Q

Differentials for neonatal jaundice - predominantly conjugated

A
  • Biliary atresia
  • Idiopathic neonatal hepatitis
  • Infection: TORCH infections
  • TPN
  • inherited disorders of bilirubin metabolism (Dubin Johnson; Rotor syndrome)
  • other inherited disorders (A1AT def; CF; galactosaemia; tyrosinaemia)
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11
Q

Causes of hypopituitarism

A

Mass lesions
Pituitary surgery
Pituitary radiation
Drug induced e.g. IFNalpha; immune checkpt inhibitor
Infiltrative lesions e.g. hypophysitis, haemchromatosis
Infarction (Sheehan syndrome)
Apoplexy
Genetic mutations
Empty sella

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12
Q

Typical order of affected hormones with hypopituitarism

A
  1. Hypogonadism
  2. GH deficiency
  3. ACTH
  4. Hypothyroidism
  5. Prolactin - rarely deficient
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13
Q

With what causes of hypopituitarism is ACTH secretion more likely to be affected? (name 2)

A

Lymphocytic hypophysitis
Immune checkpoint inhibitors

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14
Q

What does MELAS stand for?

A

Mitochondrial
Encephalomyopathy with
Lactic
Acidosis and
Stroke-like episodes

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15
Q

What does LHON stand for?

A

Leber
Hereditary
Optic
Neuropathy

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16
Q

What happens to SHBG in TSHoma vs thyroid hormone resistance?

A

Elevated in TSHoma
Normal in thyroid hormone resistance

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17
Q

What happens to alpha subunit in TSHoma?

A

Elevated alpha subunit: TSH ratio

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18
Q

Tumours associated with MEN1?

A
  1. Parathyroid
  2. Pituitary adenomas (e.g. prolactin; non-functioning; acromegaly)
  3. Pancreas (e.g. non functioning; gastrinoma; insulinoma)
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19
Q

What proportion of Familial isolated hyperparathyroidism have MEN1 mutation?

A

20%

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20
Q

What gene is affected in MEN2?

A

RET (oncogene)

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21
Q

What gene is affected in Wilsons disease?

A

ATP7B gene - affects the function of the ATPase2 membrane protein

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22
Q

What does POMC stand for?

A

Pro-opio-melanocortin

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23
Q

What hormones are produced by the corpus luteum?

A

Steroids: E2, progesterone
Non steroids: Relaxin, VEGF

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24
Q

What are the criteria for successful cannulation with AVS?

A

Adrenal vein cortisol/Peripheral vein cortisol
>/=2 at baseline
>/=3 post ACTH stimulation

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25
Q

In an AVS test, what Aldosterone:Cortisol Ratio between the 2 adrenals indicates lateralisation?

A

> 4 indicates lateralisation (ACTH stimulation)
2 may indicate lateralisation in unstimulated AVS

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26
Q

In an AVS test, how do you determine if there is contralateral suppression?

A

The unaffected adrenal gland should have an Aldosterone:cortisol ratio (ACR) less than the peripheral ACR

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27
Q

Differentials for Aldosterone Resistance

A

Medications that inhibit the epithelial sodium channel
- Potassium sparing diuretics (spironolactone, epleronone, amiloride, triamterine)
- Antibiotics - trimethoprim; pentamide

Pseudohypoaldosteronism type 1

Pyelonephritis

Obstructive uropathy

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28
Q

What are the features of pseudohypoaldosteronism type 2 (Gordon syndrome)

A

Autosomal dominant condition
Hypertension
Hyperkalaemia
Metabolic acidosis
(Normal Cr)
Low renin and aldosterone
Hypercalciuria, hypocalcaemia
Treated with thiazide diuretics

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29
Q

Causes of increased DHEAS

A
  • CAH
  • Cushings
  • Adrenal tumour
  • PCOS
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30
Q

Causes of transiently elevated prolactin

A
  • Recent seizure
  • Drug related
  • Breast feeding
  • Post coital elevation
  • Rarely Pituitary apoplexy
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31
Q

Differentials for secondary HTN in young woman

A
  • Primary hyperaldosteronism
  • Renal artery stenosis
  • Parenchymal renal disease - consider collagen disorders such as SLE
  • catecholamine producing tumours
  • Cushings
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32
Q

A bilateral total adrenalectomy in association with
ACTH-dependant Cushing’s may result in which syndrome?

A

Nelson syndrome

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33
Q

Causes of central diabetes insipidus?

A

Pituitary tumour
Neurosurgery
Head trauma

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34
Q

Causes of nephrogenic DI?

A

Lithium
Renal Dx
Hypokalaemia
Pregnancy

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35
Q

What is the cofactor for AST and ALT?

A

Pyridoxal-5-phosphate

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36
Q

What are 2 confounding factors in interpreting the level of plasma P5P

A

Albumin (plasma P5P is bound to albumin)
ALP (degrades P5P)

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37
Q

Risk factors for P5P deficiency?

A

Elderly
Alcoholism
Coeliac disease

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38
Q

What changes in LFTs would be expected with increased weight/obesity?

A

ALT increase
(note more significant increase with weight/metabolic syndrome than AST or GGT)

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39
Q

What are the half lives of ALT and AST?

A

ALT 36hrs
AST 18hrs

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40
Q

What is the half life of CK?

A

12hrs

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41
Q

What is the half life of albumin?

A

15-19 days

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42
Q

Causes of increased loss of albumin?

A

Nephrotic syndrome
Severe blood loss
Burns

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43
Q

Causes of low albumin relating to increased metabolism?

A

Sepsis
Burns
Malignancy
Hyperthyroidism

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44
Q

What happens to albumin in inflammation?

A

Reduced concentration due to decreased synthesis (inhibition by IL-6 , TNF)

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45
Q

What does SAAG stand for?

A

Serum ascites albumin gradient

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46
Q

What does SAAG of 11 or above indicate?

A

Ascites secondary to portal hypertension (e.g. CCF, cirrhosis, alcoholic hepatitis)

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47
Q

What does SAAG < 11 indicate?

A

Ascites not associated with portal hypertension (e.g. nephrotic syndrome, pancreatitis, peritoneal carcinoma, TB)

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48
Q

What is the Payne formula for corrected calcium?

A

Corrected calcium = Total calcium + 0.02 x (40 - Albumin)

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49
Q

What is the toxic metabolite that increases in paracetamol overdose and causes hepatic necrosis?

A

NAPQI (N-acetyl-p-benzoquinoneimine)

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50
Q

Causes of increased intestinal ALP?

A

Blood groups O and B - especially after a fatty meal
Cirrhosis
T2DM
Inflammatory bowel disease

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51
Q

Causes of low ALP

A

Pre-analytical - EDTA or citrate contamination
Hypophosphatasia
Zn and Mg deficiency
Untreated hypothyroidism
Bisphosphonates
Wilson disease

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52
Q

What can be used to separate bone and liver ALP on gel electrophoresis?

A

Neuraminidase
(other option is Lectin)

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53
Q

Biochemical findings in hypophosphatasia?

A

↓ALP
↑B6 in serum
↑ PEA in urine

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54
Q

What reduces NAPQI to nontoxic mercaptate and cysteine compounds for renal excretion?

A

Glutathione

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55
Q

Name 2 prognostic scoring systems for severe liver disease?

A

Child-Turcotte-Pugh
MELD (Model for End-stage Liver Disease)

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56
Q

Causes of decreased albumin

A
  • Inflammation
  • Decreased production (severe liver disease)
  • Increased loss (e.g. nephrotic syndrome)
  • Haemodilution (e.g. pregnancy)
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57
Q

Formula for “R ratio” of LFTs

A

(ALT/ALT URL)/(ALP/ALP URL)

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58
Q

What does a LFT “R ratio” of >5 indicate?

A

Hepatocellular damage

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59
Q

What does a LFT “R ratio” of <2 indicate

A

Cholestasis

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60
Q

Name the 4 types of ALP isoenzymes

A
  • Tissue non specific (Liver/Bone/Kidney)
  • Intestinal
  • Germ cell
  • Placental
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61
Q

Medications that can cause a false positive ARR due to reduced renin

A

Beta blockers
Methyldopa
Clonidine
NSAIDs
OCP

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62
Q

What medications can give false negatives of ARR?

A

ACE inhibitors
Angiotensin II receptor antagonists
Calcium channel blockers (Dihydropyridines)
Diuretics
Spironolactone

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63
Q

What is the impact of posture on aldosterone and renin?

A

Increase with standing (more pronounced increased for renin)

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64
Q

How are aldosterone and renin influenced by time of day of blood collection?

A

Circadian variation is significant for aldosterone - similar pattern to cortisol
Renin is also higher in morning and falls throughout the day

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65
Q

What is the potential impact of the luteal phase on ARR?

A

False positives are more likely in luteal phase
(Increase aldosterone and decrease renin)

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66
Q

Classic biochemical findings in salicyclate toxicity?

A

Respiratory alkalosis (hyperventilation) followed by metabolic acidosis (due to accumulation of organic acids)
Hypoglycaemia
Hypokalaemia, Hypercalcaemia

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67
Q

Biochemical Profile of HELLP syndrome (ACOG requires all 3)

A

LDH> 600
AST and ALT more than 2 x URL
Platelets < 100,000 cell/micro/L

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68
Q

Differentials for HELLP syndrome

A

Pre-eclampsia
Acute Fatty Liver of Pregnancy

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69
Q

Biochemical profile of Acute Fatty Liver in Pregnancy (Swansea criteria)

A

Elevated total bilirubin
Elevated AST or ALT
Elevated Urate
AKI
Coagulopathy
Hyperammonaemia
Hypoglycaemia

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70
Q

Presenting symptoms of Obstetric Cholestatis

A

Occurs 2nd half of pregnancy
Pruritus
RUQ pain
Nausea
Steatorrhoea
Jaundice

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71
Q

Biochemical Profile of Pre-eclampsia

A

AST and ALT >2 URL
Proteinuria (>0.3g in 24 hrs)
Hyperuricacidaemia
Raised creatinine
Thrombocytopaenia
Elevated s-Flt to PlGF ratio

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72
Q

What is the role of sFLt-1 to PlGF in assessment of pre-eclampsia?

A

High ratio -> indicates increased risk
Low ratio - can help rule out pre-eclampsia occuring within the next 2 weeks

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73
Q

Which inherited disorder has been associated with acute fatty liver in pregnancy?

A

Fetal long-chain 3-hydroxyacyl CoA dehydrogenase (LCHAD) deficiency

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74
Q

Clinical Features of obstetric cholestasis

A

Occurs 2nd half of pregnancy
Pruritus
RUQ pain
Nausea
Steatorrhoea
Jaundice

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75
Q

Biochemical profile of Obstetric Cholestasis

A

Elevated bile acids (cholic acid; Chenodeoxycholic acid)
Elevated bilirubin
AST, ALT mild rise
ALP/GGT increased

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76
Q

Which form of iron is taken up by DMT1 in the duodenum?

A

Ferrous form (Fe2+)

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77
Q

Which form of iron binds to transferrin?

A

Ferric (Fe3+)

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78
Q

Which enzymes catalyses the conversion of Fe2+ to Fe3+ to enable binding to transferrin?

A

Copper dependent ferroxidases - primary hephaestin

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79
Q

Actions of hepcidin

A
  • decrease dietary iron absorption
  • decrease iron release from liver and macrophage stores
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80
Q

Genetic mutation most commonly involved in Hereditary Haemochromatosis?

A

C282Y

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81
Q

Primary Biliary Cholangitis is an uncommon chronic autoimmune disorder that targets the …

A

small intrahepatic bile ducts

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82
Q

Primary Sclerosing Cholangitis is a chronic inflammatory disease of the biliary tree that most commonly affects the …

A

Extrahepatic bile ducts
(note that can also involve intrahepatic bile ducts)

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83
Q

Gender predominance and median age of onset in PBC vs PSC

A

PBC - females; median age 50 years
PSC - males; median age 30 years

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84
Q

What condition is associated with PSC?

A

Ulcerative colitis

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85
Q

What conditions are associated with PBC?

A

Autoimmune conditions - particularly Sjogrens syndrome and hypothyroidism

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86
Q

What is the significance of increased bilirubin in PBC?

A

Increased bilirubin in PBC is a late finding and indicates decompensation

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87
Q

How can Soluble Transferrin Receptor concentration be helpful in assessing for iron deficiency?

A

Soluble transferrin receptor concentration increases in response to iron deficiency but does not change with anaemia of chronic disease

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88
Q

Predominant raised immunoglobulin in PBC

A

IgM

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89
Q

Predominant raised immunoglobulin in autoimmune hepatitis

A

IgG

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90
Q

What are the primary bile acids?

A

Cholic acid
Chenodeoxycholic acid

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91
Q

Markers used in FIB-4 index

A

Age
AST
ALT
Platelets

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92
Q

Markers used in Hepascore

A

Age
Sex
Bilirubin
GGT
alpha2 macroglobulin
Hyaluronic acid

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93
Q

Markers used in APRI score

A

AST
Platelet count

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94
Q

Glycogen storage disorder associated with recurrent rhabdomyolysis and ‘second wind’ phenomena

A

McArdle Disease

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95
Q

What factors can increase alpha1 antitrypsin and mask deficiency?

A

Acute phase response
Oestrogen

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96
Q

Causes of decreased alpha1 antitrypsin?

A

Pre analytical factors (e.g. delayed separation of blood with increased leucocyte esterase activity)
Increased protein loss - e.g. nephrotic syndrome
Decreased synthesis
Genetic

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97
Q

Treatment of intrahepatic cholestasis of pregnancy?

A

Ursodeoxycholic acid (UDCA)

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98
Q

Main contributor to raised anion gap in methanol poisoning?

A

Formic acid

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99
Q

Main contributor to anion gap and metabolic acidosis in ethylene glycol poisoning?

A

Glycolic acid

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100
Q

Product of metabolism of ethylene glycol metabolism that can crystallise in the kidney and cause renal injury?

A

Oxalic acid

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101
Q

Causes of hypophosphataemia due to intracellular shifts (ECF to ICF)?

A

Refeeding
Glucose/fructose
Insulin
DKA
Respiratory alkalosis
Alcoholism
Severe burns
Hungry bones

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102
Q

Major causes of Fanconi syndrome?

A

Cystinosis
Wilson disease
Multiple myeloma
Heavy metal toxicity
Medications (eg tenofovir)

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103
Q

What is calprotectin

A

Small calcium binding protein in the cytosol of neutrophils with anti-microbial activity

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104
Q

Causes of raised faecal calprotectin

A

GI inflammation
- IBD
- NSAID induced
- bacterial/viral infection
- microscopic colitis
- diverticulities
- untreated coeliac disease
- colonic malignancy

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105
Q

Diagnostic criteria for acute liver failure includes:

A
  • Hepatic encephalopathy
  • INR>/=1.5
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106
Q

Causes of an increased faecal osmolar gap?

A

Carbohydrate malabsorption syndromes (e.g. lactose, fructose)
Coeliac disease
Osmotic laxatives and antacids (eg, Mg, phosphate, sulfate)
Sugar alcohols (e.g manitol, sorbitol)

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107
Q

What type of watery diarrhoea is defined biochemically by a low faecal osmolar gap?

A

Secretory

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108
Q

Calculation for faecal osmolality?

A

2(Na+K)

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109
Q

What does a negative faecal osmotic gap indicate?

A

Suggestive of phosphate or sulfate containing laxatives

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110
Q

What is the type of test used for FOBT?

A

Immunochemical test for human globin
(iFOB uses turbidimetry)

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111
Q

Role of Faecal alpha 1 antitrypsin testing?

A

Faecal AAT used to diagnose protein-losing enteropathy (eg regional enteritis, coeliac disease, Whipple disease, intestinal lymphangiectasia); cause of unexplained hypoalbuminaemia

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112
Q

Surrogate test for fat malabsorption?

A

Vitamin A level

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113
Q

Causes of increased serum ACE

A
  • Sarcoidosis
  • other granulomatous disease e.g. TB, leprosy
  • bronchitis
  • pulmonary fibrosis
  • Gauchers disease
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114
Q

Low serum ACE levels may be seen with..

A

Ace inhibitors
Steroid therapy
Some lung diseases such as bronchial carcinoma

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115
Q

Increased ACE concentration in CSF may be seen with..

A

Neurosarcoidosis
Viral and bacterial meningitis

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116
Q

Low ACE levels in the CSF may be seen with

A

Alzheimers disease
Parkinsons disease

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117
Q

Investigation that could be requested for ?fructose malabsorption

A

Breath hydrogen/methane testing

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118
Q

Enzymes located at the intestinal brush border with disaccharidase activity?

A

Sucrase
Lactase
Maltase
Trehalase

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119
Q

Sites of neuroblastoma

A

Can occur anywhere in sympathetic nervous system
* Adrenal (40%)
* Abdomen (25%)
* Thorax
* Neck/pelvis

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120
Q

Enzyme that converts noradrenaline to adrenaline in adrenal medulla

A

PNMT

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121
Q

Fractions of Metanephrines

A

Metanephrine
Normetanephrine
3-methoxytyramine (3-MT)

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122
Q

Non malignant conditions associated with increased Ca125

A
  • Menstruation
  • First trimester pregnancy
  • Benign ovarian cysts
  • PID/salpingitis
  • Endometriosis
  • CCF
  • Pleuritis/pericarditis
  • Cirrhosis (due to ascites)
  • Renal failure
  • Hypothyroidism
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123
Q

Functions of Bile

A
  • Emulsification of dietary lipids
  • Solubilisation of lipid digestion products
  • Excretion of waste products - bilirubin and cholesterol
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124
Q

Composition of Bile

A
  • Bile Acids/Salts 70%
  • Phospholipids 20%
  • Cholesterol 5%
  • Bilirubin 1%
  • Other 4%
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125
Q

Secondary bile acids

A

Deoxycholic acid
Lithocholic acid

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126
Q

Causes of mildly elevated amylase (<5 x ULN)

A
  • Salivary gland disorders e.g calculi and imflammation
  • Chronic renal failure
  • Macroamylasaemia
  • Morphine administration (spasm of sphincter of Oddi)
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127
Q

In women, AMH is secreted by..

A

Pre-antral follicles (granulosa cells)

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128
Q

Classic triad of Acrodermatitis enteropathica

A

Alopecia
Periorificial dermatitis
Diarrhoea

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128
Q

Key limitations of faecal elastase in measuring pancreatic exocrine function?

A
  • Poor sensitivity for mild disease
  • Falsely low results (false positives for disease) in people with diarrhoea
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129
Q

Alternate antibody testing in suspected coeliac disease

A
  • EMA (Endomysial antibodies)
  • Deamidated gliadin Ab (DGLA)
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129
Q

Preferred screening test for suspected coealic disease?

A

Tissue transglutaminase (TTG) IgA

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130
Q

HLA types that can be tested in suspected in coeliac disease (helpful for excluding)

A

HLA-DQ2
HLA-DQ8

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131
Q

Conditions associated with zinc deficiency

A
  • Vegetarian diet
  • Pregnancy and lactation
  • Exclusively breastfed infants > 6months
  • GI/malabsorption conditions e.g. IBD
  • Chronic illness
  • Haemoglobinopathies (sickle cell disease/thalassemia)
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132
Q

Lactose => Glucose + ____?

A

Galactose

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133
Q

Which sugar(s) can be used in a H2 breath test to assess for SIBO?

A

**Lactulose **(H2 peak earlier in gut transit time) or
Glucose (H2 detection suggests SIBO)

134
Q

Androgen that decreases in pregnancy

A

DHEAS

Due to increased metabolic clearance

135
Q

Changes to aldosterone in pregnancy

A

Aldosterone increases markedly during first trimester and continues to increase to 4 – 6×
URL

136
Q

Key changes to glucose metabolism in pregnancy

A
  • progressive insulin resistance
  • decrease fasting glucose
137
Q

Components of 1st trimester screen

A

beta HCG
PAPP-A
Nuchal translucency USS

138
Q

Components of second trimester screen

A

AFP
uE3
Free bHCG

139
Q

Pattern of PAPP-A and beta HCG increasing gestation (weeks 9-13 of pregnancy)

A

↑PAPP-A
↓hCG

140
Q

Pattern of bHCG and PAPP-A with increasing risk in first trimester screening

A

↓PAPP-A
↑hCG

141
Q

Normal trend of second trimester screening analytes with increasing gestation

A

↑AFP
↑uE3
↓free beta hCG

142
Q

A CDT level above the cut off indicates…

A

Excessive alcohol use
>50g ethanol per day for >14 days

Can be increased in non alcoholic liver disease e.g. hepatic malignancy

143
Q

What does PEth stand for and what does it indicate?

A

Phosphatidylethanol - indicates recent alcohol intake (within 2-4 weeks)

144
Q

Sample used for PEth measurement

A

EDTA whole blood

145
Q

What does EtG stand for and what does it indicate

A

Ethyl glucuronide - indicates recent alcohol use (within 3 days)

146
Q

Sample used for EtG (Ethyl Glucuronide) measurement

A

Urine

147
Q

Direct biomarkers of ethanol consumption

A
  • ethyl glucuronide,
  • ethyl sulfate
  • phosphatidylethanol (PEth)
148
Q

Indirect biomarkers of ethanol consumption

A
  • carbohydrate deficient transferrin (CDT)
  • mean corpuscular volume (MCV)
  • liver enzymes (AST, ALT, GGT)
149
Q

Effect of obesity on GH levels

A

GH levels are lower in obesity

150
Q

Effects of obesity on lipids

A

Increase triglycerides
Lower HDL

151
Q

Chromogranin A may be elevated with NETs including..

A

Phaeochromocytomas
GI and pancreatic endocrine tumours
Carcinoid syndrome
Small cell lung Ca
Neuroblastoma
Medullary thyroid Ca

152
Q

Most common cause of pancreatic exocrine insufficiency in children

A

Cystic fibrosis

153
Q

Pancreatic enzymes

A

Amylase
Lipase
Pepsidases - Trypsin, Chymotrypsin and Elastase

154
Q

Causes of pancreatic exocrine insufficiency in children

A
  • Genetic conditions (CF, others e.g. Pearson syndrome)
  • Development anomalies
  • Pancreatic resection
  • Chronic/recurrent pancreatitis e.g. autoimmune

Consider secondary causes of malabsorption e.g. infection, coeliac disea

155
Q

What is a neuroendocrine tumour

A

Malignant growth that (sometimes) secretes bioactive peptides or amines

156
Q

Causes of false positives for Gastrin measurement

A
  • PPIs
  • Achlorhydric atrophic gastritis (withour tumours)
  • Conditions associated with hyperchlorhydria (e.g. H, pylori infections)
157
Q

What does VIP stand for

A

Vasoactive intestinal peptide

158
Q

Conditions associated with MEN1

A
  • Hyperparathyroidism (95%)
  • Pancreatic tumours (30-80%)
  • Pituitary adenomas (30-40%)
159
Q

Conditions associated with MEN2A

A
  • Medullary thyroid carcinoma (95%)
  • Phaeochromocytoma (40%)
  • Hyperparathyroidism (10-20%)
160
Q

Conditions associated with MEN2B

A
  • Mucosal neuromas (99%)
  • Marfan body habitus (99%)
  • Medullary thyroid carcinoma (95%)
  • Phaeochromocytoma
161
Q

What are Lights criteria for classifying pleural fluid as an exudate

A

*Pleural fluid-to-serum protein ratio > 0.5
*Pleural fluid-to-serum LDH ratio > 0.6
*Pleural fluid LDH greater than 0.67 (ie, two-thirds) the upper limits of the laboratory’s normal serum LDH

162
Q

‘Routine’ tests on pleural fluid (name 5)

A

*Protein
*LDH
*cell count
*glucose
*cholesterol

163
Q

Standard B12 (total B12) assays may be low with

A

Pregnancy
Oestrogen therapy
Neutropenia
Haptocorrin deficiency (rare)

164
Q

The active form of B12 is that bound to..

A

Transcobalamin

165
Q

Clinical uses of BNP (name 4)

A
  • Diagnosis or exclusion of HF
  • monitoring progresion of disease & response
  • screening for PAH in scleroderma
  • cardiac amyloidosis monitoring and staging (with cardiac troponin)
166
Q

Clinical features of chronic Lithium toxicity

A

o Nephrogenic DI
o Primary hyperparathyroidism
o Thyroid: hypothyroidism
o Neurological e.g. confusion, ataxia

167
Q

Where is procalcitonin produced?

A

Produced by the parafollicular cells of the thyroid and
neuroendocrine cells of lung and intestine.

168
Q

BNP is predominantly secreted from..

A

Left ventricle cardiac myocytes

169
Q

Half life of BNP vs NT-proBNP

A

BNP 20 mins
NT-proBNP 2 hours

170
Q

Expected change in free T3 and free T4 in pregnancy

A

Mild decrease is seen in late pregnancy

171
Q

For heart failure patients treated with neprilysin inhibitors, which cardiac marker is preferred?

A

NT-proBNP is preferred

BNP concentration has been found to increase with treatment

172
Q

Stimulators of BNP production

A
  • Atrial distension
  • Angiotensin II stimulation
  • Endothelin
  • Sympathetic stimulation
173
Q

Time course of troponin elevation post MI

A

Rises by 2-3 hours post (using hsTN assay), peaks at 18-24 hours.
Elevated for 10 days post AMI

174
Q

Syndrome of apparent mineralocorticoid excess affects which enzyme

A

11-beta-hydroxysteroid dehydrogenase enzyme type 2

11-beta-HSD2 is kidney isoform. Converts cortisol ->cortisone

175
Q

Most important test for laboratory to offer for assessment of acute porphyria?

A

Urine PBG

High sensitivity and specificity for current acute porphyria attack

176
Q

Definition of microalbuminuria expressed as albumin excretion per day?

A

30-300mg/24 hrs

177
Q

The laboratory definition of Tumour Lysis Syndrome is at least 2 of which 4 biochemical features?

A
  • Hyperuricaemia
  • Hyperkalaemia
  • Hyperphosphataemia
  • Hypocalcaemia
178
Q

What does ROMA stand for?

A

Risk of Ovarian Malignancy Algorithm

179
Q

How is high uric acid treated in tumour lysis syndrome?

A

Rasburicase

180
Q

Pre-analytical issue for patients on Rasburicase?

A

Continues to breakdown uric acid ex vivo -> falsely low values

Must keep cool at collection/transport, centrifuged, analysed promptly

181
Q

Phaeochromocytomas/Paragangliomas are tumours of what cell type

A

chromograffin cells

182
Q

“Classic triad” of phaeochromocytoma presentation

A
  • episodic headach (90%)
  • sweating (60%)
  • tachycardia
183
Q

Biomarkers for Neuroblastoma

A
  • urine homovanillic acid (HCA)
  • urine vanillylmandelic acid (VMA)
  • chromogranin A - correlated with tumour burden and response to treatment in stage 3-4 neuroblastomas
184
Q

Types of islet cell tumours

A

Insulinoma
Glucagonoma
Somatostatinoma
Gastrinoma
VIPoma

185
Q

Medications that can cause low Mg due to renal losses

A
  • Diuretics - loop and thiazide
  • Antibiotics e.g. aminoglycosides
  • Cisplatin
  • Antibodies targetin EGF receptor (e.g. cetuximab)
  • Calcineurin inhibitors
186
Q

Which type of porphyria typically occurs in childhood?

A

Erythryopoietic Protoporphyria (EPP)

187
Q

Types of Acute Porphyrias

A
  • ALA dehydratase deficiency (ADP)
  • Acute intermittent porphyria (AIP)
  • Hereditary coproporphyria (HCP)
  • Variegate porphyria (VP)
188
Q

Types of Non-Acute Porphyrias

A
  • X-linked dominant protoporphyria (XLDPP)
  • Congenital erythropoietic porphyria (CEP)
  • Porphyria Cutaenea Tarda (PCT)
  • Erythropoeitic Protoporphyria (EPP)
189
Q

Most common type of renal stone

A

Calcium oxalate

190
Q

Types of renal stone

A
  • Calcium oxalate – most common
  • Mixed calcium oxalate - phosphate
  • Calcium phosphate (8%)
  • Uric acid (8%)
  • Struvite (Mg ammonium phosphate) 12%
  • Cysteine (1-2%)
191
Q

What is Homocysteine

A

Intermediary amino acid formed by the conversion of methionine to cysteine

192
Q

Classical homocystinuria results from deficiency in which enzyme

A

Cystathionine beta-synthase (CBS)

193
Q

Clinical features of Homocystinuria

A
  • Developmental delay
  • Marfanoid appearance
  • Osteoporosis
  • Ocular abnormalities
  • Thromboembolic disease
  • Severe premature atherosclerosis
194
Q

The transsulfuration of homocysteine to cysteine by CBS requires ____ as a cofactor

A

Pyridoxal phosphate (vitamin B6)

195
Q

What does urine PBG stand for?

A

Urine Porphobilinogen

196
Q

Causes of raised urine porphyrins

A
  • Porphyria

Secondary porphyrias (mainly coproporphyrin)
* Cholestatic liver disease
* Lead poisoning
* Heavy metals (gold, arsenic)
* some haematological disorders

197
Q

A peak at 626nm on plasma fluorescence is a hallmark of which type of porphyria?

A

Variegate Porphyria

198
Q

On HPLC Faecal profiling for porphyrias, which is the hallmark compound of PCT?

A

Isocoproporphyrin

199
Q

Causes of hypophysitis

A
  • Lymphocytic hypophysitis (most common)
  • Complication of immunotherapy (e.g. ipilimumab)
  • Granulomatous
  • IgG4-associated
200
Q

Causes of increased serum total bile acids

A
  • Intrhepatic cholestasis of pregnancy
  • Acute hepatitis
  • Chronic hepatitis
  • Liver sclerosis
  • Liver malignancy
201
Q

If no clear cause of increased serum uric acid on initial assessment, what further test could be performed?

A

Fractional urinary excretion of uric acid

202
Q

Biochemical features of refeeding syndrome

A

Hyperinsulinism
Hypophosphataemia
Hypokalaemia
Hypomagnesaemia
Low thiamine

203
Q

Biochemical features of Tumour Lysis Syndrome

A

Hyperphosphataemia
Hyperkalaemia
High LDH
Hyperuricaemia
Hypocalcaemia

204
Q

Impacts of Amiodarone on TFTs

A
  • reduced T4 to T3 conversion
  • Transient increase TSH with treatment commencement
  • Thyrotoxicosis
  • Hypothyroidism (failure to escape Wolff-Chaikoff effect)
205
Q

Adverse effects on the endocrine system of immune checkpoint blockade

A
  • Thyroid disease
  • Hypophysitis
  • Adrenal insufficiency
  • Insulin deficient DM
  • Hypoparathyroidism
206
Q

Types of ALP isoenzymes

A
  • Tissue non specific (Bone, Liver, Kidney)
  • Intestinal ALP
  • Placental ALP
  • Germ cell ALP (“Placental like ALP”)
207
Q

A copeptin measurement of >4.9 can help exclude..

A

AVP deficiency

208
Q

The kidney removes acid by 3 main mechanisms:

A
  1. Excretion of “titratable acids”
  2. Reabsorption of bicarbonate
  3. Excretion of ammonium (generation of bicarbonate)
209
Q

What are “titratable acids” excreted in urine

A
  • Phosphate
  • Citrate
  • Urate
  • Hippurate

Group of conjugate bases acting as buffers.

210
Q

Most (70-80%) of the filtered bicarbonate in the kidney is reabsorbed in the …

A

Proximal tubules

Most of the remainder is reabsorbed via the thick ascending limb

211
Q

Main mechanism in kidney which increases in response to significant acid load

A

Increased ammonium excretion

212
Q

Type 1 RTA affects the …

A

Distal tubules.

Impaired urinary proton excretion

213
Q

Causes of Type 1 RTA

A
  1. Primary - Genetic mutations
  2. Secondary
    - Autoimmune disorders (including Sjogrens syndrome)
    - Drugs e.g. Amphotericin B
    - Hypercalciuric conditions
214
Q

Biochemical Picture of Type 1 RTA

A
  • NAGMA
  • Hypokalaemia
  • Urine pH > 5.5
  • Low urine ammonium
  • Low urine bicarbonate
  • Hypercalciuria (renal stones common)
215
Q

Type 2 RTA affects the ..

A

Proximal tubules

Impaired bicarbonate reabsorption

216
Q

Biochemical features of Fanconi syndrome

A

Hypophosphataemia
Hyperphosphaturia
Glycosuria
Proteinuria and aminoaciduria

217
Q

Biochemical Picture of Type 2 RTA

A
  • NAGMA
  • high urine bicarbonate
  • hypokalaemia
  • low urine pH
  • elevated urinary ammonium
218
Q

Biochemical picture of Type 4 RTA

A
  • NAGMA (mild if present)
  • Hyperkalaemia
  • appropriately low urine pH (<5.5)
  • low urine ammonium
  • low urine bicarbonate
219
Q

Elevated fractional excretion of bicarbonate is diagnostic of which type of RTA?

A

Type 2 RTA

220
Q

Proxy measurement of urine NH4+

A

Urine anion gap

221
Q

Functional deficiency of aldosterone is what type of RTA?

A

Type 4

222
Q
A
222
Q

Calculation of urine anion gap

A

Na + K - Cl

223
Q

In a type 1 RTA (distal tubular defect), the urinary anion gap will be ..

A

Positive

224
Q

Causes of marked increase in bone remodelling

A
  • Pagets disease
  • Hyperthyroidism
  • Malignancy
  • Late offset of Denosumab
225
Q

Negative acute phase reactants (name 6)

A
  • Albumin
  • Pre-albumin
  • Transferrin
  • AFP
  • IGF-1
  • TBG
226
Q

Positive acute phase reactants

A
  • Complement system - C3, C4
  • Fibrinogen; Plasminogen
  • Haptoglobin
  • Anti-proteases
  • Caeuruloplasmin
  • CRP
227
Q

A negative urine anion gap (-20 or less) indicates..

A

Increased ammonium excretion.
Occurs in patients with metabolic acidosis secondary to diarrhoea

228
Q

Urine anion gap can be unreliable in measuring NH4+ in the setting of “unmeasured” anions such as…

A

Ketones
Hippurate (toluene inhalation)

UAG not reduced as occurs when ammonium is excreted with chloride

229
Q

Urine osmolar gap of <150 in a patient with chronic metabolic acidosis is suggestive of

A

Type 1 or type 4 RTA

230
Q

An intrauterine pregnancy should be visible when the hCG is at what level?

A

1500 - 2000 IU/L

231
Q

Type of Cryoglobulin associated with monoclonal immunoglobulin

A

Type 1

232
Q

Type of cryoglobulin composed of a mixture of a monoclonal IgM (or IgG or Iga) with RF activity and polyclonal IgG

A

Type 2

Often associated with Hep C;
Autoimmune diseases - SLE, Sgorens

233
Q

Type of cryoglobulins composed of mixture of polyclonal IgG and polyclonal IgM

A

Type 3

Often secondary to autoimmune disorders

234
Q

Causes of low SHBG

A
  • Obesity
  • Insulin resistance
  • PCOS
  • Hypothyroidism
  • Nephrotic syndrome
  • Prolactin, androgen, corticosteroid or GH increase
235
Q

Patients that form Lipoprotein X

A
  • cholestatic liver disease
  • mutations or deficiencies in LCAT

LCAT = Lecithin-Cholesterol Acyltransferase. Esterifies cholesterol.

236
Q

What is lipoprotein X composed of

A

Phospholipids, free cholesterol, ApoA1, Albumin

Lacks ApoB100

237
Q

Principal role of chylomicrons

A

Delivery of dietary lipids to hepatic and peripheral cells

238
Q

Principal role of VLDL

A

Major carriers of endogenous (hepatic derived) TGs

Shuttle TGs from liver to peripheral tissue

239
Q

Lipoproteins that contain ApoB100

A

LDL, Lipoprotein(a), IDL, VLDL

240
Q

Lipoproteins that contain ApoE

A

CM
VLDL
IDL

ApoE binds remnant receptors (liver)

241
Q

Causes of chylous effusions

A
  • Surgery
  • Malignancy (lymphoma)
  • Lymphatic malformations
242
Q

Causes of pseudo chylous effusions

A

Rheumatoid pleurisy
Tuberculosis

243
Q

Presence of bilirubin in the CSF indicates Hb has been in the CSF for how long

A

12 hrs to 2 weeks

244
Q

2 tests to identify CSF:

A
  • beta-2 transferrin (tau protein)
  • beta trace protein
245
Q

Normal pattern for CSF for
- glucose
- protein
- chloride

A
  • glucose about half plasma
  • very low protein (<0.4g/L)
  • chloride about 5-10mmol/L higher than plasma
246
Q

Markers of Alzheimers disease in CSF

A
  • Abeta 1-42 decrease
  • P-tau increase
  • Ratio of P-tau: Abeta 1-42 increased
247
Q

Causes (mechanisms) of increased L-Lactate

A
  1. Defect in pyruvate oxidation (tissue hypoxia or defect in TCA cycle; mitochondrial resp chain)
  2. Defect in rate limiting enzymes of glycolysis
  3. Excess cytosolic NADH
248
Q

Do laboratory methods detect D-lactate

A

No. L-LO and L-LDH is used in the assays

249
Q

The main ketone that starts to increase after fasting 12-14 hours is

A

Beta- hydroxybutyrate

250
Q

Biochemical changes in DKA (on K, P, Na, Cr)

A
  • Initial hyperkalaemia
  • Hyperphosphataemia (low after treatment)
  • Hyponatreamia
  • Falsely elevated Cr using Haffe method (interference from ketones)
251
Q

Flucloxacilin and paracetamol can result in a HAGMA due to accumulation of…

A

5- oxoproline (Pyrogluamic acid)

252
Q

Inherited causes of increased triglycerides

A
  • Familial hyperchylomicronaemia (type 1) - e.g. lipoprotein lipase deficiency
  • Familial dysbetalipoproteinaemia (type 3)- ApoE2
  • Familial combined hyperlipoproteinaemia - polygenic
  • Primary hypertriglyceridaemia (type 4) - unknown genetics
253
Q

Secondary causes of increased TG

A
  • Diabetes mellitus
  • Obesity
  • MAFLD
  • Alcohol excess
  • Nephrotic syndrome (chol more affected)
  • Pregnancy
  • Medications: Glucocorticoids, Oestrogen, Diuretics (e.g. chlorothiazide)
254
Q

What does PKU stand for

A

Phenylketonuria

255
Q

Classic PKU affects which enzyme

A

Phenylalanine Hydroxylase

Affects conversion of phenylalanine to Tyrosine

256
Q

What calculation may be used to further assess hyper or hypokalaemia?

A

Transtubular potassium gradient (TTKG)

Estimates the degree of renal potassium excretion in the distal nephron

257
Q

During hyperkalaemia, the TTKG should be …

A

Greater than 7

Lower values suggest hypoaldosteronism

258
Q

During hypokalaemia, the TTKG should be..

A

Less than 3

Greater values suggest renal potassium wasting

259
Q

Measures needed to calculate TTKG

A
  • Urine K
  • Urine osmolality
  • Plasma osmolality
  • Plasma K
260
Q

Causes of increased LDH

A
  • MI
  • Pneumonia
  • CCF
  • hepatic injury
  • Haemolysis
  • Ineffective haematopoesis
  • Skeletal muscle injury
  • Renal injury
  • Pancreatitis
  • Tumour - especially testicular or lymphoma
261
Q

hCG can be used as a tumour marker in which malignancies

A
  • Germ cell tumours (Germinomas; Choriocarcinomas)
  • Gestational trophoblastic disease
262
Q

Name 5 bone formation markers

A
  • ALP - Alkaline phosphatase
  • Bone specific ALP
  • P1NP - Procollagen Type 1 N propeptide
  • P1CP - Procollagen Type 1 C propeptide
  • Osteocalcin
263
Q

Name 5 bone resorption markers

A
  • CTX - Carboxy-terminal crosslinking telopeptide of type 1 collagen
  • NTX - Amino-terminal crosslinking peptide of type 1 collagen
  • DPD - Deoxypyridinoline
  • PYP - Pyridinoline
  • TRACP - Serum tartrate-resistant acid phosphatase
264
Q

Limitations of BTMs

A
  • Reflect total skeletal turnover
  • Not always specific to bone metabolism
  • Substantial biological variability
  • Multiple assays for same analyte
  • Do not assess osteocyte activity
265
Q

Main sites of cortical bone in the body

A

Skull and long bones

266
Q

Main sites of trabecular bone in the body

A

Vertebrae
Ribs
Distal ends of long bones

267
Q

Biochemical profile of Acute Fatty Liver of Pregnancy (Swansea criteria)

A
  • Elevated total bilirubin
  • elevated AST or ALT
  • hyperammonaemia
  • elevated urate
  • hypoglycaemia
  • AKI
  • coagulopathy
  • Leukocytosis
268
Q

Changes to binding globulins in pregnancy

A

Increase TBG, CBG, SHBG

269
Q

Changes to glucose in pregnancy

A

BSL lower approx 20%

Increase in insulin

270
Q

Changes to calcium in pregnancy

A
  • total calcium lower due to lower albumin
  • free/ionised calcium stable
  • increase 1,25(OH) vit D - palcental. Increased GIT absorption.
  • Hypercalciuric mother
  • Maternal PTH decreases first half pregnancy
  • PTHrP - ca across placenta to fetus
271
Q

Changes to Cr in pregnancy

A

Decreases 20-30mmol/L
(increase in GFR)

272
Q

Changes to Free T4/T3 in pregnancy

A

Decreases late pregnancy

273
Q

Aldo and renin changes in pregnancy

A

Increase aldosterone by 8 weeks
Increase renin and aldosterone mostly by 3rd trimester

274
Q

Changes to androgens in pregnancy

A

Increase
Except for DHEAS which decreases

275
Q

What is a neuroendocrine tumour

A

A malignant growth that (sometimes) secretes bioactive peptides or amines

276
Q
A
277
Q

Clinical use of CRH Stimulation Testing

A

May be combined with IPSS in diagnosing Cushing disease
- Measure ACTH and cortisol post CRH injection

Significant rise in ACTH or cortisol from baseline- suggests pituitary

278
Q

Contraindications for Clonidine suppression test

A

Clonidine can cause hypotension
and is contraindicated in frail patients with a history of hypotensive episodes/ severe coronary/ carotid
disease

279
Q

How to interpret clonidine suppression test

A

Abnormal test result (indicating a PPGL) includes:
- an elevation of plasma normetanephrine at
3 h after clonidine administration
- <40% decrease in levels compared with
baseline

280
Q

Medications that can interfere with clonidine suppression test

A
  • Beta blockers - avoid for 48 hours prior
  • Paracetamol, diuretics, TCAs - at least.5 days
  • Caffeine, smoking - avoid for 24 hours
281
Q

What is exercise growth hormone testing used to investigate?

A

Suspected GH deficiency

282
Q

What is Glucagon stimulation test used for?

A

Suspected GH deficiency

283
Q

Interpretation of Glucagon stimulation test:

A

Normal response is any GH > 3ug/L

Cut off based on lean subjects.
Lower GH response in obesity group.

284
Q

Effects of glucagon

A

Stimulates glycogenolysis in the liver
Stimulates GH and ACTH release form the pituitary

285
Q

Risk associated with performing Glucagon stimulation test

A

Risk of late hypoglcycaemia

286
Q

Interpretation of IPSS

A

A central to peripheral ACTH ratio of
≥ 2 pre CRH and / or a ratio of ≥ 3 post CRH is
consistent with Cushing’s disease

287
Q

With an IPSS, If the central to peripheral ACTH ratios are not elevated on either side, what does this indicate?

A
  • may have ectopic source of ACTH or
  • petrosal sinus was not succesfully cannulated

Petrosal sinus/peripheral prolactin ratio >1.8 - adequate cannulation

288
Q

What is struvite

A

Magnesium ammonium phosphate

289
Q

Causes of hyperoxaluria

A
  • usually acquired e.g. compromised ileal function; low calcium intake
  • primary hyperoxaluria is rare

Calcium binds oxalate and prevents absorption

290
Q

Analytes to measure in urine for investigation of renal stones

A
  • Calcium
  • oxalate
  • urate
  • cysteine
  • citrate
291
Q

Causes of hypocitraturia

A

Most commonly acidosis or acid retention
- distal renal tubular acidosis
- metabolic acidosis of chronic diarrhoea
- lactic acidosis from physical exercise

Can also occur with UTIs

292
Q

Contraindications to OGTT

A

History of bariatric surgery

Increased risk of hypoglycaemia

293
Q

Serum glucose levels in keeping with DM

A

Fasting >/=7.0
Random or 2 hour >/=11.1

294
Q

Normal cut offs for OGTT (non pregnant)

A

Fasting </=6
Random <7.8

295
Q

Cut offs for pregnacy OGTT

A

Fasting <5.1
1 hr <10
2 hr <8.5

296
Q

Cut off for normal response in oral glucose suppression test for GH excess

A

Normal response is GH <1.0ug/L at any timepoint

297
Q

Causes of false positives in oral glucose suppression test for GH excess

A
  • Poorly controlled DM
  • Nutritional disorders (e.g. anorexia nervosa)
  • Renal disease
  • Liver failure

Associated with acquired GH insensitivity to glucose suppression

298
Q

Causes of false positives for low dose Dexamethasone suppression test

A
  • Non compliance
  • Malabsorption
  • Drugs inducing the hepatic metabolism of dex (e.g. carbamazepine, phenytoin)
  • Drugs elevating CBG (oestrogens)
  • CKD
299
Q

How to interpret high dose dexamethasone suppression test

A

Decrease in serum cortisol >50% is suggestive of pituitary Cushing disease (rather than ectopic ACTH)

However sensitivity and specificity approx 80%

300
Q

Why is a late night salivary cortisol performed before an IPSS?

A

To confirm if in active phase of hypercortisolism

False results can occur in patients not in active phase when tested

301
Q

Role of bone ALP in CKD MBD

A
  • high results predict #
  • high results can help exclude adynamic bone disease
302
Q

Effect of Romosozumab on bone turnover markers

A
  • Initial increase in P1NP then return to baseline
  • Decrease CTX
303
Q

Effect of teriperatide on bone turnover markers

A
  • Increase in P1NP
  • Increase in CTX

Intermittent PTH -> increases Wnt signalling, promotes bone formation

304
Q

Type of bone affected with prolonged elevated PTH

A

Cortical > trabecular bone loss

305
Q

What level of copeptin indicates complete central DI

A

Copeptin <2.6pmol/L WITH prior fluid deprivation (>8 hours)

306
Q

What level of copeptin indicates nephrogenic DI

A

Copeptin >21.4pmol/L WITHOUT prior fluid deprivation

307
Q

Intrepretation of TRH Stimulation test

A

TSH-oma: TSH rarely increases following TRH
Thyroid hormone resistance - > 4 fold increase in serum TSH

308
Q

How to differentiate TSHoma and thyroid hormone resistance

A
  • SHBG and CTX are elevated in hyperthyroidism (TSHoma)
  • Alpha subunit elevated in 70% TSH-oma (not helpful in post menopausal women)
  • TFT testing in 1st degree relatives if available
  • THRB gene test - thyroid hormone resistance
309
Q

How do ammonia levels in infants compare to adults?

A

Higher levels in infants, especially pre-term infants

310
Q

Endocrine effects of Lithium

A
  • Thyroid - inhibits release of T4/T3 - hypothyroidism (or subclinical hypothyroidism)
  • PTH - higher set point for calcium; parathyroid hyperplasia; can worsen PHPT
  • Renal - Nephrogenic DI
311
Q

Examples of Anti-TNF agents used in treatment of autoimmune conditions (e.g. IBD)

A
  • Infliximab
  • Adalimumab (Humira)
312
Q

Lack of lateralisation with an AVS test can occur with:

A
  • Bilateral aldosterone producing adenoma
  • Bilateral adrenal hyperplasia
  • Glucocorticoid Remediable Aldosteronism
313
Q

Changes to prolactin with GAHT

A
  • Prolactin increases with E2
  • Decreases or unchanged with testosterone
314
Q

Features differentiating MGUS from MM

A
  • Clonal BM plasma cells <10% in MGUS
  • M protein <30g/L in MGUS (any level in MM)
  • Absence of CRAB SLiM criteria

CRAB SLiM crtiteria includes involved/uninvolved serum FLC ratio >100

315
Q

Phaeochromocytomas tend to produce..

A

Both Noradrenaline and Adrenaline

316
Q

Paragangliomas tend to produce..

A

Noradrenaline

317
Q

What is the enzyme that converts Norepinephrine to Epinephrine and where is it located

A

PNMT
Expressed in the adrenal medulla

Not expressed in sympathaetic neurons

318
Q

Catecholamines includes

A
  • Adrenaline
  • Noradrenaline
  • Dopamine
319
Q

Metanephrtines (metabolites of catecholamines) includes

A
  • Metanephrine
  • Normetanephrine
  • 3-Methyoxytyramine (3MT)
320
Q

Tests for medullary thyroid carcinoma

A
  • Calcitonin
  • CEA
  • Genetic testing - RET mutations
  • Testing for coexisting tumours - Ca/PTH, plasma free metanephrines
321
Q

Clinical causes of increased TMP/GFR

A
  • Thyroxine
  • GH/IGF-1
  • Hypoparathyroidism
  • Insulin
  • Etidronate (bisphosphonate)
  • Catecholamine
  • Calcitriol
  • After unilateral ureteric obstruction
322
Q

Intestinal absorption of phosphate is via the .. transporter

A

NAPT IIb

Dependent on 1,25(OH)D

323
Q

Non pathological causes of short stature

A
  • Ethnic short stature
  • Familial short stature
  • Constitutional growth delay
324
Q

GH Stimulation Test can use..

A
  • Exercise
  • Glucagon
  • Arginine
  • Clonidine
325
Q

Endocrine causes of short stature

A
  • GH deficiency or receptor defector
  • Hypthyroidism
  • T1DM - poorly controlled
  • Cushings
326
Q

PSA in serum is mostly bound to…

A

Alpha-1-antichymotrypsin

327
Q

Functional role of PSA

A

Present in seminal fluid in high concentrations. Cleaves the high molecular mass simnal vesicle protein Semenogelin

328
Q

Whcih has greater cardiac specificity - cTnI or cTnT?

A

cTnI

Raised cTnT but normal cTnI in some pts with skeletal muscle disease

329
Q

Differentials for increased urine porphyrins but with normal faecal porphyrins

A
  • Liver disease
  • Medications
  • Lead poisoning
330
Q

Causes of increased serum beta 2 microglobulin

A
  • Haematological disorders e.g. leukaemia, lymphoma, myeloma*
  • Viral infections - Hepatitis
  • CT disorders - SLE
  • IBD
  • Solid malignancy - e.g. hepatoma
  • Hyperthyroidism
  • Renal impairment

*Used in staging of Multiple Myeloma

331
Q

Name of criteria used for Tumour Lysis Syndrome

A

Cairo-Bishop criteria

332
Q

Definition (criteria) of laboratory tumour lysis syndrome

A

≥2 key metabolic features that present within three days before or seven days after instituting chemotherapy:
* Hyperkalaemia - >6mmol/L or increase 25% from baseline
* Uric acid - increase 25% from baseline
* Hyperphosphataemia - or increase 25% from baseline
* Hypocalcaemia - <1.75mmol/L or decrease 25% from baseline

333
Q

Definition (criteria) of Clinical Tumour Lysis Syndrome

A

Clinical TLS – Laboratory TLS plus ≥1 of the following findings that are not directly or probably attributable to a therapeutic agent:
* increased serum creatinine concentration (≥1.5 times the upper limit of normal),
* cardiac arrhythmia/sudden death, or
* seizure.

RCPA Part 1 (6 decks)

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