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My flashcards > Phase 2 - Haematology > Flashcards

Phase 2 - Haematology Flashcards

1
Q

3 catagories of anaemia

A

Microcytic (MCV <80)

Normocytic (MCV 80-95)

Macrocytic (MCV >95)

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2
Q

Causes of microcytic anaemia

A

TAILS

  • Thalassaemias
  • Anaemia of chronic disease
  • IRON DEFICIENCY

(lead poisoning)
- Sideroblastic - unable to put iron into haemoglobin - linked to alcohol excess, heavy metal poisoning, VIt B deficiency (Als deficiency - iron trapped in mitochondria - autosomal recessive)

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3
Q

Causes of normocytic anaemia

A
  • BLOOD LOSS (acute - too rapid to adjust)
  • HAEMOLYTIC (high cell turnover)
    • SICKLE CELL
      (- Malaria)
    • Hereditary spherocytosis - spherocytes are more fragile (a membranopathy)
    • G6PDH (glucose 6 phosphate dehydrogensase) deficiency - haemolysis occurs when exposed to certain triggers
    • Autoimmune Haemolytic anaemia
  • Non-haemolytic (low reticulocytes)
    • aplastic anaemia
    • CKD - normal cells, just fewer present)
    • Myelophthisic - bone marrow failure due tp malignant invasion
    • HAEM MALIGNANCY
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4
Q

Causes of macrocytic anaemia

A
  • Megaloblastic causes (related to impaired DNA synthesis)
    • B12 DEFICIENCY
    • Folate deficiency
  • Non-megaloblastic (nothing wrong with DNA synthesis)
    • HYPOTHYROID
    • ALCOHOL
    • LIVER disease (increase membrane cholesterol of RBCs - increased surface area)
      • esp NAFLD
    • CKD
    • Bone marrow failure (esp MDS - increased immature RBCs)
    • drugs (Methotrexate, hydroxyurea)

(Haemolytic anaemia - more rbcs destroyed so more young, large reticulocytes present)

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5
Q

Iron metabolism process

A

~15-20mg average daily intake but only ~1mg (or 10%) absorbed in DUODENUM
- actively transported into DUODENAL EPITHELIAL CELLS by intestinal HAEM TRANSPORTER (HCP1) - highly expressed in duodenum

Some stored intracellularly bound to FERRITIN (usually - more easy to mobilise) in:
- reticuloendothelial cells (e.g. monocyte derived - esp in liver)
- hepatocytes
- skeletal muscle

or in HAEMOSIDERIN:
- in macrophages (esp liver, spleen, bone marrow)

Circulating iron bound to TRANSFERRIN
- transports to bone marrow to make erythrocytes

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6
Q

Iron deficiency anaemia - causes

A

most common cause of anaemia

Blood loss:
- menorrhaegia
- Hookworm (leading cause of deficiency worldwide)
- GI bleeding

Poor diet: - esp in children (uncommon in adults) - esp in poverty
- PROLONGED BREAST FEEDING in infants (poor Fe source)

Malabsorption - Coeliac disease, IBD

Increased demands (growth, pregnancy)

RARE in ELDERLY - RED FLAG SIGN for COLON CANCER BLEEDING (recomen urgent endoscopy for any >60y/o w/ Fe def)

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7
Q

Risk factors for iron deficiency

A
  • Less developed countries/poverty
  • High veg diet (iron best absorbed from animal products)
    • VEGAN
  • premature infants
  • Delayed introduction of mixed feeding (breastmilk contains less iron)
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8
Q

Signs and symptoms of anaemia

A

Symptoms (non-specific):

  • FATIGUE, headaches and faintness
  • Dyspnoea
  • Intermittent claudication (ischaemic pain in peripheries)
  • COLD
  • PALPITATIONS
  • Angina (if there is pre-existing coronary disease)
  • Anorexia

Signs (may be absent even in severe anaemia):

  • Pallor (esp conjunctival)
  • Brittle hair
  • Leukonychia (white patches on nails)
  • Tachycardia
  • Systolic flow murmur
  • Cardiac failure
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9
Q

presentation of iron deficiency

A
  • anaemic symptoms
  • Brittle nails/hair
  • spoon nails (koilonychia - dip in nails)
  • tongue papillae atrophy (atrophic glossitis)
  • ulceration of corners of mouth (angular cheilitis/stomatitis)
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10
Q

Diagnosis of iron deficiency anaemia

A
  • Blood film
    • low blood count
    • MICROCYTIC and HYPOCHROMATIC
    • pokilocytosis (variation in shape); anisocytosis (variation in size)
    • TARGET CELLS (bulls eye pattern - non specific)
    • HOWELL JOLLY BODIES (nucleated RBCs - non-specific)
  • LOW FERRITIN (diagnostic)
    • tho it is an acute phase protein so will be normal/high in inflammation even if anaemic
  • IRON STUDY:
    • low serum iron (not very useful)
    • LOW TRANSFERRIN SATURATION <19%
      (more transferrin made to bind as much iron as possible so higher quantity of transferrin which is not saturated)
    • HIGH TOTAL IRON BINDING CAPACITY (lots of transferrin so highly bound)

(high serum soluble transferrin receptors)

  • LOW RETICULOCYTE count

Further examinations if blood loss (e.g. GI tract exam)

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11
Q

Management of iron deficiency

A

Treat underlying cause

ORAL IRON - FERROUS SULPHATE
- Side effects:
* nausea, abdo discomfort, diarrhoea/constipation, black stools (from increased free iron)
- Vit C improves absorption
- Alt: FERROUS GLUCONATE

If severe:
- IV/IM iron
* rare anaphylaxis; potential sub epidermal staining

Hb should increase by 20 every month - continue for 3 months after Hb/MCV normal to replenish stores

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12
Q

Define thalassaemia

A

reduced production of a specific Hb chain type - IMBALANCE OF Hb SYNTHESIS
- causes INEFFECTIVE ERYTHROPOIESIS (death of precursors in bone marrow from precipitation of globin chain imbalance)
- precipitation in mature RBCs -> HAEMOLYSIS

Beta Thalassaemia - reduced B chain
Alpha thalassaemia - reduced A chain

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13
Q

Beta thalassaemia - pathophysiology

A

low B chain synthesis = EXCESS A CHAINS
- combine with delta + gamma chains
- increased HbA2/HbF

Usually caused by point mutations (>200 varieties)
-> defects in transcription, RNA splicing/modification, translation -> UNSTABLE B-GLOBIN - can’t be utilised

If heterozygous - ASYMPTOMATIC microcytosis; maybe MILD anaemia

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14
Q

3 variations in b-thalassaemia presentation

A

B-THALASSAEMIA MINOR (aka carrier/trait)

B-THALASSAEMIA INTERMEDIA (symptomatic but not requiring regular transfusions)

B-THALASSAEMIA MAJOR (severe homozygous - requires lifelong transfusions)

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15
Q

How do you differentiate between B-thalassaemia minor and iron deficiency

A

Both have hypochromic, microcytic RBCs

BUT serum ferritin/iron stores normal

Hb electrophoresis -> raised HbA2 and often raised HbF

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16
Q

Presentation of B-thalassemia intermedia

A
  • SPLENOMEGALY (from haemolysis)
  • Bone deformaties
  • Recurrent leg ulcers
  • Gallstones
  • Infection
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17
Q

Presentation of B-thalassaemia major

A

Presents in children in 1ST YEAR OF LIFE

  • failure to thrive - recurrent bacterial INFECTION
  • severe ANAEMIA from 3-6 months (when switch to HbA)
  • EXTRAMEDULLARY HAEMATOPOIESIS - ineffective RBC OUTSIDE MARROW
    -> HEPATOSPLENOMEGALY (from haemolysis)
  • bone marrow expansion (distictive appearance)

Clinically:
- hair on end skull x-ray
- bone abnormalities

  • Low MCV - MICROCYTIC
  • Blood film: large and small irregular hypochromic RBCs
  • NORMAL SERUM FERRITIN
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18
Q

Diagnosis of homozygous b-thalassaemia

A

BLOOD COUNT and FILM
- HYPOCHROMIC, MICROCYTIC anaemia
- RAISED RETICULOCYTES
- NUCLEATED RBC in PERIPHERALS

Haemoglobin electrophoresis - increased HbF; absent/less HbA

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19
Q

Treatment of beta-thalassaemia

A

In more severe:

  • regular (2-4 weeks) LIFE-LONG transfusions to keep Hb above 90g/L AND SUPPRESS ineffective EXTRAMEDULLARY HAEMATOPOIESIS
    -> to allow normal growth
  • Splenectomy if hypersplenism persists -> INCREASING TRANSFUSION DEMANDS
    • do after childhood -> reduce infection risk
  • Bone marrow transplant
  • Long term FOLIC ACID
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20
Q

Complications of blood transfusion

A

INCREASED IRON LOADING -> overload

  • Mainly deposit in liver/spleen -> liver fibrosis/cirrhosis
  • also in endocrine glands + HEART ->
    • Diabetes
    • Hypothyroidism
    • Hypocalcaemia
    • Premature death
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21
Q

Treatments for the complications of blood transfusions

A

IRON-CHELATING agents - STOP iron OVERLOAD
- oral DEFERIPRONE
- sub-cutan DESFERRIOXAMINE
- side effects: cataracts, deafness

ASCORBIC ACID (large dose) -> increases urinary exc of iron

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22
Q

Pathophysiology of Aplha-thalassaemia

A
  • 2 copies of gene for a-goblin on both chromosomes 16 normally
  • in a-thalassaemia: 1 (most common) or both of the genes are deleted on one or both chromosomes
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23
Q

Clinical presentation of 4 alpha-globin gene deletion

A

INCOMPATIBLE WITH LIFE - stillborn/die shortly after birth
- HYDROPS FETALIS
* Pale
* Oedematous
* hepatosplenomegaly

(Only Hb Barts present - 4 gamma chains - can’t carry O2)

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24
Q

Presentation of 3 gene alpha-globin deletion

A

HbH disease (common in parts of asia) - severe alpha reduction

HbH = 4 beta chains

Moderate ANAEMIA and SPLENOMEGALY

Usually not transfusion dependant

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25
Q

Presentation of 2 gene a-globin deletion

A

trait/ CARRIER

MICROCYTOSIS - potential MILD ANAEMIA

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26
Q

Presentation of 1 gene a-globin deletion

A

Usually normal blood picture

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27
Q

Treatments for a-thalassaemia

A

DAILY FOLIC ACID

Blood transfusions as needed (-> chelation therapy)

May need splenectomy or venesectomy

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28
Q

Pathophysiology of sickle cell anaemia

A

SINGLE BASE MUTATION: ADENINE -> THYMINE
- VALINE substituted for GLUTAMIC ACID (6th CODON) in BETA-GLOBIN chain

-> HbS -> INSOLUBLE + POLYMERISES when DEOXYGENATED -> sickling (RIGID)

Initially reversible but repeated sickling -> lose membrane flexibility -> IRREVERSIBLY SICKLED
- DEHYDRATED + DENSE
- shortened RBC survival -> HAEMOLYSIS
- impaired passage through microcirculation
-> OBSTRUCTION, INFARCTION, PAIN

Also get cytopenias of other cell types (esp NEUTROPENIAS) as bone marrow focusses on producing more ineffective RBCs

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29
Q

What precipitates sickling

A
  • Infection
  • Dehydration
  • Cold
  • Acidosis
  • Hypoxia
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30
Q

Why do sickle cell patients often feel well despite being anaemic (when not in crises)

A

HbS release oxygen more readily (lower oxygen binding affinity)

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31
Q

Clinical presentation of sickle cell trait

A

Symptom free but can sickle under increased hypoxia/stress e.g. anaesthesia, upressurised aircarft
- vaso-occlusion may occur

PROTECTIVE against FALCIPARUM MALARIA

Slight increased risk of renal disease/cancer

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32
Q

Conditions caused by homozygous sickle cell anaemia

A

Vaso-occlusive crises

ACUTE CHEST SYNDROME

Pulmonary hypertension

Anaemia
- can complicate to BONE MARROW APLASIA (usually after PARVOVIRUS B19 infection)

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33
Q

S&S of vaso-occlusive crisis + complications

A
  • ACUTE PAIN
    • HANDS and FEET (dactylitis) in KIDS
    • LONG BONES such as the femur, spine, ribs and pelvis - ADULTS
    • vaso-occlusion of small vessels and AVASCULAR NECROSIS of BONE MARROW
  • Possible CNS infarction in children
    -> stroke, seizures and cognitive defects
  • Attacks vary in frequency - can occur as much as every day to once a year depending on patient
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34
Q

What occurs in Acute chest syndrome + S&S + causes

A

PULMONARY VASO-OCCLUSIVE CRISIS
(occurs in 30%)

Caused by INFECTION (CHLMYDIA, MYCOPLASMA, STREP PNEUMONIAE)
-> FAT EMBOLISM from NECROTIC BONE MARROW
OR
-> PULMON INFARCT - SEQUESTRATION of sickle cells

SOB, CHEST PAIN, HYPOXIA (vicious cycle)

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35
Q

Define pulmonary hypertension

A

Mean pulmonary artery pressure greater than 25mmHg
(checked by right heart CATHETERISATION - inserted into right heart)

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36
Q

Pulmonary hypertension in sickle cell

A

Occurs in 10% of patients

  • Most probably caused by damage from repeated chest crises and repeated thromboembolism and intravascular haemolysis
  • Increases the risk of hypoxaemia and worsening sickle cell crises

Common cause of death in adults with SCD

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37
Q

Anaemia in SCD

A

Stable low haemoglobin in CHRONIC HAEMOLYSIS

ACUTE FALL:
- SPLENIC SEQUESTRATION
-> splenomegaly + acute fall in Hb
-> Fibrotic, non-functioning spleen (potentially)
- BONE MARROW APLASIA
- PARVOVIRUS B19 (slapped cheek appearance) INVADES PROLIFERATING ERYTHROID PROGENITORS
-> NO RETICULOCYTES IN PERIPHERAL - FAILURE OF ERYTHROPOESIS in marrow
* Aplastic crisis

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38
Q

Long term complications of SCD

A

Growth + development delayed

Avascular necrosis of hips, shoulder; compression of vertebrae; shortening of peripheral small bones
- Osteomylelitis from S. aureus, S. pneumoniae, Salmonella

Cardiomegaly, arrhythmias (+ iron overload cardiomyopathy)
- MI

25% -> TIA, fits, cerebral infarcts, coma

Chronic hepatomegaly + dysfunction

Chronic tubulointersitial nephritis

Retinopathy/detachment, vitreous haemorrhage

Impaired placental flow in pregnancy -> spontaneous abortion

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39
Q

Diagnosis of SCD

A

Blood count:
- Hb 60-80 g/L
- RAISED RETICULOCYTES

Blood film - SICKLED ERYTHROCYTES

SICKLE SOLUBILITY TEST - positive

Hb ELECTROPHORESIS [- DIAGNOSTIC]
- 80-95% HbS (NO HbA)

Best to diagnose with CORD BLOOD at BIRTH -> PROMPT PNEUMOCOCCAL PROPHYLAXIS

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40
Q

General reatment of SCD

A

Avoid/rapidly treat precipitating factors e.g. prophylaxis vaccine

FOLIC ACID for all HAEMOLYTIC ppl

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41
Q

Treatment for acute painful attacks in SCD

A

IV fluids

ANALGESIA (morphine, codeine, paracetamol, NSAIDs)

O2 + antibiotics if needed

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42
Q

Treatment for SCD anaemia

A

BLOOD TRANSFUSION (iron overload risk)
- Acute chest syndrome
- Acute anaemia due to acute splenic sequestration
- Aplastic crisis
- Stroke
- Heart failure

ORAL HYDROXYCARBAMIDE/HYDROXYUREA
- Increases HbF conc

Stem cell transplant

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43
Q

How long can body store folate

A

Low stores for ~ 4 months

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44
Q

Where is folate absorbed

A

Duodenum/proximal jejunum

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45
Q

Folate deficiency pathophys

A

Folate - essential for DNA synthesis

In deficiency:
-> impaired DNA synthesis
-> DELAYED NUCLEAR MATURATION
-> large RBCs + decreased RBC production

Affects all cells in body but BONE MARROW most affected due to HIGH ACTIVITY

Also needed for fetal development so -> neural tube defects

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46
Q

Causes of folate deficiency

A

POOR INTAKE (main cause)

Increased demand (pregnancy, increased cell turnover - haemolysis, malignancy, inflam disease, renal dialysis)

MALABSORPTION (coeliac/crohn’s)

ANTIFOLATE DRUGS (METJOTREXATE, TRIMETHOPRIM)

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47
Q

Risk factors for folate deficiency

A
  • Elderly
  • Poverty
  • Alcoholic
  • Pregnant
  • Crohn’s/coeliac
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48
Q

Presentation of Folate deficiency

A

May be asymp

Symptoms of anaemia

GLOSSITIS can occur (sore tongue)

NO NEUROPATHY (unlike B12)

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49
Q

Diagnosis of folate deficiency

A

Blood count/film:
- MEGALOBLASTIC
- MACROCYTIC RBCs
- OVAL MACROCYTES and HYPERSEGMENTED NEUTROPHILS (>=6 lobes) in peripheral film

SERUM + RBC folate - LOW

GI investigation to exclude

Serum bilirubin may be high - from ineffective erythropoiesis -> increased haemolysis

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50
Q

Treatment of folate deficiency

A

FOLIC ACID TABLETS daily for 4 months - BUT ONLY WITH NORMAL B12/B12 SUPPLEMENTS! (may worsen B12 def -> spinal cord degeneration)

Treat underlying cause

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51
Q

What food is folate found in

A

Green veg (spinach, broccoli)
Nuts
Yeast
Liver

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52
Q

What food is B12 found in

A

Meat
Fish
Dairy
(NOT PLANTS)

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53
Q

How long do B12 body stores last

A

4 years

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54
Q

How is B12 absorbed

A

Binds to INTRINSIC FACTOR from PARIETAL CELLS (in stomach)

Absorbed in TERMINAL ILEUM

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55
Q

Pathophys of B12 deficiency

A

ESSENTIAL for THYMIDINE -> DNA synthesis

IMPAIRED DNA synth -> DELAYED NUCLEAR MATURATION
-> Megaloblasts + reduced RBC production

Bone marrow most affected (high activity)

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56
Q

Causes of B12 deficiency

A

Dietary (vegans)
Malabsorption (lacking intrinsic factor, ileal resection)
PERNICIOUS ANAEMIA (most common)

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57
Q

Risk factors for Pernicious anaemia

A

Elderly (>60)
FEMALE
Fair-haired, blue-eyed
Blood group A
OTHER AUTOIMMUNE (Thyroid, Addison’s)

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58
Q

Pathophys of pernicious anaemia

A
  • Parietal cell antibodies (present in 90% - but NON-SPECIFIC)
  • INTRINSIC FACTOR ANTIBODIES (only present in 50%)

-> Autoimmune gastritis of FUNDUS - plasma cell/lymphoid INFILTRATION

Parietal/CHIEF cells REPLACED BY MUCIN-SECRETING cells

-> ACHLORHYDRIA (reduced HCl)
-> ABSENT INTRINSIC FACTOR secretion

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59
Q

Presentation of B12/Pernicious anaemia

A

INSIDIOUS ONSET - increasing symp of anaemia

Potential LEMON-YELLOW skin - pallor + mild jaundice (from haemolysis)

GLOSSITIS + ANGULAR CHEILOSIS/STOMATITIS (potentially)

NEURO FEATURES if V. LOW B12:
- Symmetrical parasthesia - fingers + toes
- LOSS OF VIBRATION + PROPROCEPTION (1ST thing lost)
- Progressive weakness/ataxia
-> potential PARAPLEGIA

Dementia, psychiatric problems, hallucinations, delusions
and optic atrophy may occur
(from vitamin B12 deficiency)

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60
Q

Diff diagnosis for pernicious anaemia (megaloblastic + B12 def)

A

Folate def (also megaloblastic) - no neuropathy

Other causes of B12 deficiency
- Terminal ileum disease/bacterial overgrowth

Gastrectomy

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61
Q

Diagnosis of pernicious anaemia

A

Blood count/film:
- MEGALOBLASTIC
- MACROCYTIC
- Peripheral: OVAL MACROCYTES + HYPERSEGMENTED NEUTROPHILS

Potential raised biliirubin

LOW SERUM B12
LOW Hb + RETICULOCYTE COUNT

INTRINSIC FACTOR ANTIBODIES (DIAGNOSTIC)
(- low sensitivity, not present in all patients)

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62
Q

Treatment of B12 deficiency

A

If malabsorption - INJECTIONS
-> IM HYDROXOCOBALAMIN

Oral B12 if dietary

Treat other underlying causes

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63
Q

Prophylactic folate in pregnancy (dose)

A

400mg for first 12 weeks

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64
Q

Types of leukaemias

A

Acute Lymphoblastic leukaemia (lymphoblast)
Acute Myeloid lukaemia (myeloblast)
Chronic myeloid leukaemia (myeloid progenitor???)
Chronic Lymphocytic leukaemia (B lymphocyte)

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65
Q

Markers of high cell turnover in haemolytic anaemia

A

INCREASED LDH (lactate dehydrogenase - enzyme of cell turnover), and UNCONJ BILIRUBIN (from haemolysis)

LOW HAPTOGLOBIN (protein that binds to free haem - lots of free haem in haemolysis so haptoglobin being used up)

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66
Q

How do you differentiate between Normocytic anaemias

A

Non haemolytic (CKD, malig, Endocrine, mixed) have low reticulocytes

Can differentiate between Blood loss/haemolysis by presence of cell turnover markers in haemolysis

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67
Q

How to differentiate between microcytic anaemias

A

IRON PANEL:
- Ferritin low, TIBC high (iron def)
- Feritin normal, TIBC low, low serum iron (chronic disease)
- HIGH serum iron + low TIBC (Thal/Sideroblastic)

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68
Q

Risk factors for AML

A
  • AGE > 65
  • Down’s, Patau’s (trisomy 13) and Klinefelter’s (XXY) syndrome
  • Chemo (METHOTREXATE) - previous treatment
  • Previous heamatological disorders e.g. MDS
  • Irradiation
  • Benzene exposure
  • inherited genetic conditions (e.g. Fanconi’s anaemia, ataxia telangiectasia, germilne TP53 mutation (tumour suppressor gene))
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69
Q

Pathophys of AML

A

Rapid proliferation of immature myeloid blasts in bone marrow, peripheral blood or extramedullary tissues (Granulocytes are not being made)

Rapid progression if not treated quickly (3y survival)

Defined by >= 20% blast cells in BM OR PERIPHERAL blood

Acute promyelocytic leukaemia subtype is particularly characterised by hypergranular promyelocytes + Auer rods and is linked to t(15:17)

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70
Q

Presentation of AML

A

BONE MARROW FAILURE:
- functional pancytopaenia
* Anaemia = pallor, fatigue, dizzy, palpitations
* Neutropenia = infections
* Thrombocytopaenia = bruising (ecchymosis or petechiae), bleeding (esp muscosal)
- bone pain

TISSUE INFILTRATION:
- swollen gums
- skin/testicular mass
- Hepatoplenomegaly
- lymphadenopathy

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71
Q

What is Plummer-Vinson syndrome

A

Web-like growth of membrane in throat from iron deficiency

Dysphagia, Upper oesophageal webs, IRON DEFICIENCY ANAEMIA

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72
Q

Diagnosis of AML

A

FBC/Blood film:

  • AUER RODS (dark rods in cytoplasm of neutrophils)
  • neutropenia (can have normal/high WCC)
  • Anaemia
  • Thrombocytopenia
    • coag panel typically normal tho - abnormal suggests DIC
  • serum LDH may be raised
    + U+E, LFTs, RFTs, etc

Bone marrow BIOPSY (aspirate or trephine) or Peripheral BLOOD SMEAR >= 20% MYELOBLASTS (definitive, gold standard)
- typicaly paler nuclei + lack of cell variety

History of pre-esisting malignancy (esp MYELODYSPLASTIC SYNDROME or Myeloproliferative neoplasm e.g. polycythaemia vera)

Acute promyelocytic leukaemia = t(15:17)

Immunophenotyping = -ve for TdT (terminal deoxynucleotidyl transferase) + +ve for myeloperoxidase

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73
Q

Differential diagnosis of AML

A
  • Haematinic deficiency (B12/folate/iron)
  • Infection (e.g. retroviral, herpervirus)
  • Meds
  • Autoimmune
  • Liver disease
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74
Q

Management of AML in fit individual

A

CHEMO - ~4-6 weeks (~4 cycles)
(ATRA for acute promyelocytic leukemia - subtype)
- HICKMAN/PICC LINE or portacath

Supportive measures:
- transfusions
- treat infections
(- fertility cryopreservation)

Check basline cardiac, liver + renal function (blood tests, ECHO etc.) - damage can occur from chemo

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75
Q

Side effects of chemo

A
  • Nausea/vomiting (antiemetics routinely given)
  • Altered bowel habit (diarrhoea/ constipation)
  • Loss of appetite
  • Reduced fertility
  • Fatigue
  • Allergic reactions to chemo +/- other supportive medications

CYTOPENIAS (need transfusions + prophylactic antimicrobials)

Bystander organ damage

Hair loss

76
Q

Less intensive (non curative) treatments for AML

A

Outpatient - for older/less fit

  • Azacytidine +/- venetoclax
    Low dose subcutaneous cytarabine
    Trial drugs e.g. targeted therapy FLT3i, IDH2i (specifc genes)

Supportive measures

77
Q

Pathophysiology of CML + Risk Factors

A

presence of BCR-ABL gene fusion in PHILADELPHIA CHROMOSOME (t(9:22))
-> IRREVERSIBLY ACITIVATES TYROSINE KINASE

TYROSINE KINASE INCREASES CELL PROLIFERATION
- inhibits apoptotic pathway - JAK-STAT -> increased haematopoesis
-> myeloid hyperplasia of bone marrow

> =20% blasts on BM biopsy = Blast crisis -> AML

RFx:
- AGE 65-74
- Ionising radiation
- Male

78
Q

Symptoms of CML

A

General leukaemia symptoms (BONE MARROW FAILURE + BONE PAIN)
- hyperviscosity (headaches, thrombosis)

MASSIVE HEPATOSPLENOMEGALY (if alongside malaria esp) -> abdo discomfort

B symptoms potentially (hypermetabolic) - weight loss, malaise, night sweats (from tissue infiltration) + fever

79
Q

Diagnosis of CML

A

Genetic/Cytogenic tests for BCR-ABL/Philadelphia chromosome
- use either qRT-PCR or fluorescent in situ hybridisation (FISH)

  • FBC - pancytopenia (but granulocytosis/leukocytosis) + raised WCC
  • Metabolic panel (potential raised K+, LDH, uric acid)
  • Peripheral blood smear: mature/maturing myeloid cells
    • Basophil >= 20% = accelerated phase

Blast cell % shows severity - phases
(>10 chronic - best; accelerated phase - >=15, <30; >=20 BLAST CRISIS - can accelerate into AML)

BM biopsy - INCREASED GRANULOCYTES (diagnostic)

80
Q

Treatment for CML

A

IMATINIB (400mg daily) - TK inhib
Chemo
- monitor FBC for haem normalisation
- reassess/monitor every 3 months

May need allogenic transplant

Very treatable - 40% chance of no recurrence after deep remission

81
Q

Differentials for high WCC

A

Common - infection (c. difficle, tb, shigella)

Steroids or g-csf (granulocyte colony stimulating factor - growth factor)
Ethylene glycol (in polyester + antifreeze - poisoning I suppose)

MI
Mesenteric ischaemia
Gangrene

Paraneoplastic (non-haem malignancies - abnormal bone marrow response to neoplasm)
(haem malignancies uncommon)

82
Q

Pathophys of acute lymphoblastic leukaemia

A

Genetic mutation + rapid uncontrolled proliferation of lymphoblasts/lymphoid progenitor cell -> replacing normal haematopoetic cells in BM + infiltrating organs

  • B cell lineage more commonly affected - linked to t(12:21)

Good prognosis

83
Q

Risk factors for ALL

A

Particularly affects children <5 y/o

Genetic:
- DOWN’S
- Neurofibromatosis (tumors that affect nervous system)
- FHx

Folate metabolism polymorphisms

  • Hx of malignancy
  • Radiation
  • Chemo
84
Q

Presentation of ALL

A

BONE MARROW FAILURE + BONE PAIN
- Anaemia (pallor, fatigue)
- Thrombocyotpenia (bruising, bleeding etc)
- Neutropenia -> infections + fever

Tissue infiltration:
- Hepatosplenomegaly
- Swollen testes, kidneys, lymph nodes, skin
- B symptoms - weight loss, malaise, night sweats (MORE COMMON than in AML/CML)

Can get CNS involvement -> neuro signs, raised ICP, meningism etc

85
Q

Diagnosis of ALL

A

FBC - pancytopenia
Bloodfilm - INCREASED LYMPHOBLASTS

Blood film - 1x10^9 lymphoblasts per L

BM BIOPSY - >=20% LYMPHOBLASTS (DIAGNOSTIC)
+ hypercellular + lymphoblastic infiltration

Immunofluroscence/phenotyping - TdT +ve lymphoblasts, but myeloperoxides -ve (opposite of AML)
(TdT = terminal deoxynucleotidyl transferase - oligoclonal market characterising undifferentiated/poorly differentiated lymphoid blasts)

86
Q

Treatment for ALL

A

Chemo:
- prednisolone/dexamethasone
- cyclophosphamide
- vincristine
- doxorubicin/daunorubicin

+ Methotrexate for CNS prophylaxis

consider allo transplant

Tyrosine kinase inhib if philadelphia chromosome +ve

87
Q

Pathophys of Chronic lymphocytic leukaemia

A

INSIDIOUS/Indolent accumulation of incompetent mature lymphocytes, esp B cells (become continuously activated -> monoclonal b-cell lymphocytosis -> CLL) that occurs with increasing age
- failure of cell apoptosis
- lymphocytosis is sustained for at least 3 months

  • > 5 x 10^9/L

accumulation in BM (can crowd out functional cells?) -> BM failure

88
Q

Presentation of CLL

A

Oft asymp

Lymphadenopathy (NON TENDER)

  • BM FAILURE - pancytopenia
  • Hepatosplenomegaly

Potentially B symps

89
Q

Risk factors for CLL

A

Age > 60
Male
Genetics - FHx; White ethnicity

90
Q

Diagnosis of CLL + Tx

A

FBC - WCC = lymphocytosis; cytopenia for rbcs, plts, other wc

Blood film - SMUDGE CELLS (old, broken)

May do BM biopsy (infiltration/overcrowding); CT scan (hepatosplenomegaly)

Tx:
- If asymp: observation
- Symp: immunochemotherapy e.g.
- High dose methylprednisolone + anti-CD20 (e.g. Rituximab)

91
Q

Complication of CLL

A

Richter transformation
- massive B cell acumulation in lymph nodes
-> massive lymphadenopathy
-> transforms to aggressive lymphoma

92
Q

Most common leukaemia in kids

A

ALL

93
Q

Most common leukaemia in general/adults

A

CLL

94
Q

Reactive vs cancer lymph nodes

A

Reactive - TENDER (+ has hilum?)

Cancer - rounded, rubbery, growing, NON-TENDER

95
Q

Define lymphoma

A

Accumulation of cancerous lymphocytes forming tumour in lymph nodes

96
Q

Risk factors for Lymphoma

A

EBV - glandular fever (in developing)
HIV (in developed)
SLE
Sjogrens (reduced fluid production e.g. tear/spit)
AGE (Hodgekin’s esp in TEENS + ELDERLY)

97
Q

Presentation of Hodgekin’s lymphoma

A
  • RFx
  • B SYMPTOMS

PAINLESS, RUBBERY LYMPHADENOPATHY
- PAINFUL AFTER DRINKING ALCOHOL

98
Q

Diagnosis of Hogekin’s

A

LYMPH NODE BIOPSY (incisional or needle core biopsy, NOT fine needle biopsy)
- REED STERNBERG cell +ve (big, paler, looks multinucleated)
- subtype (nodular lymphocyte predominant Hodgekin’s) -> POPCORN CELLS (popcorns are nodular)

Bloods:
- HIGH LDH (turnover - from metabolic panel)
- LOW Hb (anaemia of chronic disease)
- HIGH ESR (inflam)

CT/MRI for staging

99
Q

Staging of lymphomas

A

ANN ARBOUR STAGING

1 - single lymph node
2 - 2 or more on one side of diaphragm
3 - 2 or more on both sides of diaphragm
4 - extra-nodal metastasis

A - no B symptoms
B - B symptoms present

100
Q

Treatment for Hodgkin

A

ABVD chemo - 2 cycles:
Doxorubicin (Adriamycin)
Bleomycin
Vinblastine
Dacarbazine

+ interim PET/CT

101
Q

Severe complication of chemo

A

FEBRILE NEUTROPENIA
- esp on high dose

Fever, tachycardia, sweats, rigors, tachypnoea

TREAT WITH BROAD SPECTRUM ANTIBIOTIC (amoxicillin, fluroquinolone)

102
Q

Types of non-Hodgkin lymphomas

A

Low grade/indolent - slow growing, don’t always require treatment, generally incurrable

High grade/aggressive - rapid but can be cured with timely treatment

103
Q

Which cells can lymphomas affect

A

B, T (rare, poor prognosis) or natural killer cells

B lymphocytes most common (due to somatic hypermutation when trying to get right antibodies)

104
Q

Types of indolent lymphomas

A

Marginal Zone lymphoma

Follicular Lymphoma

Mantle cell lymphoma

105
Q

Types of high grade lymphomas

A

Diffuse Large B cell lymphoma

Burkitt Lymphoma

106
Q

Complication of Low grade lymphoma

A

Richter’s transformation -> aggressive, diffuse B cell lymphoma

Compression syndrome (could also get in high grade - fast growing)

107
Q

Which drug is a risk factor for indolent lymphomas

A

Methotrexate (chemo + arthritis)

108
Q

Symptoms of non-hodgkin lymphomas

A

PAINLESS RUBBERY LYMPADENOPATHY
- NOT AFFECTED BY ALCOHOL

B SYMPTOMS

indolent oft ASYMP or a LUMP - usually advanced at presentation

109
Q

Diagnosis of Non-hodgkin lymphoma

A

FBC
LDH
ESR

CORE NEEDLE/EXCISION LYMPH NODE biopsy:
- NO RS/POPCORN
- BURKITT’S - CHARACTERISTIC STARRY SKY

Can also do BM biopsy

CT/PET/MRI - for staging

for differentials:
Organ functions
Viral screen
G6PD
Uric acid
B2 microglobulin

110
Q

Why are fine needle biopsies unhelpful for lympadenopathy

A

They only extract fluid not tissue

111
Q

Treatment of Low grade lymphoma

A

Asymp:
- watch + wait
- REGULAR follow-up (3-6 months)

Symp:
- Radiotherapy (could potentially cure)

Biologics:
BCL2 INHIBITOR - prevents anti-apoptosis

IMiDs (immunomodulatory imide drugs)

BiTE and CAR-T (risk of cytokine release syndrome)

112
Q

Treatment of high grade lymphoma

A

Immunochemotherapy, with autograft

Radiotherapy

Check Point inhib (release host immune -> increased activity/ability)

Mononuclear antibodies

BITE/CAR-T

Allogenic transplant (uncommon)

113
Q

Complication of allogenic transplant

A

Graft vs Host disease (tho a stronger immune reaction tends to fight off cancer better in long-run if graft is tolerated)

114
Q

What is the standard Chemo used for non-Hodgkin lymphoma

A

R-CHOP:
Rituxumab (CD20 Ab),
Cyclophosphamide,
Hydroxydaunorubicin,
Vincristine,
Prednisolone (steroid)

115
Q

Define multiple myeloma

A

Malignant monoclonal proliferation of plasma cells
- typically 1 specific Ab - esp IgG (55%) and IgA (20%)(“monoclonal paraprotein”)

> 10% PLASMA CELLS IN BONE MARROW

116
Q

Risk factors for multiple myeloma

A

AGE (>70)
Afrocarribean
HIV

117
Q

Symptoms of MM

A

Old CRAB or CRABBI

Old (>70)

hyperCALCAEMIA
RENAL Failure
- hypercalcaemia -> calcium oxalate stones
- Ig light-chain deposition (nephrotoxic) - BENCE JONES PROTEIN

ANAEMIA (BM failure)
BONE LYTIC LESIONS

Bleeding
Infections

118
Q

Pathophys of MM

A

Lack of apoptosis of differentiated b-lymphocytes. These plasma cells return to the bone marrow and overcrowd it reducing the production of other haem cells. This leads to bone marrow failure -> anaemia (tired all the time), thrombocytopaenia (bruising/bleeding), neutropenia (infections) except increased plasma cells.

Also causes bone lytic lesions -> hypercalcaemia as calcium from bone is releases. Some osteoporosis so pathological fractures can occur. Overall some profound bone deformity.

Hypercalcaemia increases risk of calcium oxalate renal stones. The increased deposition of the light kappa chains of immunoglobulins (ie Bence jones protein) in the kidneys is also NEPHROTOXIC -> kidney failure and Bence Jones protein in urine.

119
Q

Diagnosis of MM

A

Bloods
- pancytopenia (NORMOCYTIC NORMOCHROMIC anaemia);
- HYPERCALCAEMIA
- Raised ESR

Blood film:
- Peripheral Rouleaux formation (RBCs stacking like coins in a line) - PATHOGNOMONIC

U+E - renal failure
- XR to check for stones

Urine dipstick - BENCE JONES protein

BONE profile
- HYPOcalcaemia + RAISED ALP
BM ASPRIATE - >10% PLASMA CELLS

SERUM ELECTROPHORESIS
- BAND for specific Ig paraprotein (hypergammaglobulinaemia - normally spread out)

XR SKULL - PEPPER POT SKULL
- osteolytic lesions

120
Q

Differential diagnosis of MM

A

MGUS (mammyloid gammopathy undefined significance)
- precursor to myeloma (found in 10% at 80 y/o)

ASYMP
<10% BM plasma cells
no/little paraprotein spike

Amyloidosis (green on histology)

oft get end-stage renal failure

121
Q

Treatment of MM

A

ONLY TREAT IF SYMPTOMATIC

CHEMO
MONOCLONAL ANTIBODIES - DARATUMUMAB
Bisphosphates (alendoronate)

Kyphoplasty - inject cement to support vertebrae
- blood transfusion
Consider BM stem cell transplant

122
Q

Complication of MM

A

Richter transformation

123
Q

Primary causes of Polycythaemia

A

POLYCYTHAEMIA VER (JAK2 V617 mutation)

EPO receptor mutation
(High O2 affinity Hb? seems more secondary)

124
Q

Secondary causes of polycythaemia

A

HYPOXIA

HIGH EPO secretion

can also get RELATIVE POLYCYTHAEMIA from:

  • ACUTE DEHYDRATION
  • CHRONIC = apparent polycythaemia e.g in:
    • EXCESS ALCOHOL,
    • OBESITY,
    • HTN
125
Q

Pathophys of polycythaemia vera

A

Malignant proliferation of a pluripotent stem cell clone (clonal disordaer) caused by JAK2 mutation (a tyrosine kinase) which transduces signals (esp from things like erythropoietin)

The clones DON’T NEED EPO to AVOID APOPTOSIS

Excess proliferation of all haematopoietic cell lines = polycythaemia = raised haematocrit = HYPERVISCOSITY + THROMBOSIS

126
Q

Presentation of polycythaemia vera

A

May be ASYMP - more common >60 y/o

Vague symp (common normally in old ppl anyways) from hyperviscosity:
- Headaches
- Tired
- Dizziness
- Visual disturbance
- Tinnitus

SEVERE ITCHING AFTER HOT BATH/when WARM

Erythromelalgia - burning sensation in fingers/toes

  • HTN
  • Angina
  • Intermittent claudication
  • Plethoric complexion - congested with blood in facial skin

HEPATOSPLENOMEGALY - distinguishes it as a malignancy
- may also get gout from high turnover

127
Q

DIagnosis of PV

A

FBC:
- EVERYTHING raised (distinguishes from RBC only)
- RAISED Hb/HAEMATOCRIT

Genetic screen - JAK2 MUTATION

BM biopsy (prominent erythroid, granulocytic and
megakaryocytic proliferation)

LOW serum EPO

128
Q

Treatment of PV

A

VENESECTION - LOWER HAEMATOCRIT + PLTS
- remove 400-500ml WEEKLY
(ft sole treatment)

Chemo:
- Hydroxycarbamide + Bulsulfan (esp if poorly controlled e.g. thrombocytocsis)
- Low dose ASPIRIN

Radioactive Phosphorus seeds (ONLY >70 y/o - increased risk of leukaemia)

129
Q

Medication for gout

A

ALLOPURINOL - block uric acid production

130
Q

In which diseases may Howell Jolly bodies be seen on microscopy

A
  • MEGALOBLASTIC ANAEMIAS
  • Sickle cell disease
    – Iron deficient anaemia
131
Q

Presentation of essential thrombocytosis

A
  • SPLENOMEGALY
  • ARYTHOMELALGIA (red/blue discoloration + burning in peripheries)
  • LIVEDO RETICULARIS (purply rash)
132
Q

Types of Haemophilia

A
  • Haemophilia A – Factor 8 deficiency
    • Treatment – IV Factor 8
  • Haemophilia B – Factor 9 deficiency
133
Q

Epidemiology of Haemophilia

A
  • X-linked recessive disorders – mainly affects men
  • Haemophilia A is more common
134
Q

Pathophysiology of Haemophilia A

A

X linked gene mutation causes FVIII deficiency. Leads to insufficient formation of tenase complex (IXa, VIIIa - ie the things that activate X), reduced thrombin generation, impaired fibrin deposition and poor clot formation.

The extrinsic pathway is also unable to compensate for the intrinsic deficit as it is down-regulated by TFPI (tissue factor pathway inhibitor) and the fibrinolytic pathway is up-regulated due to the low thrombin.

(2nd paragraph is extra info)

135
Q

Symptoms/signs of Haemophilia

A

Depends on plasma levels of F8/9

  • Levels <1 IU/dL (SEVERE) - associated with frequent spontaneous bleeding into muscles and joints -> crippling arthropathy
  • 1-5 IU/dL - severe bleeding following injury + occasional apparently spontaneous episodes
  • > 5 IU/dL - mild disease: bleeding only with trauma/surgery

General s&s:

  • Cerebral haemorrhage more common (than in general pop)
  • Easy bruising
  • Haematomas
  • Prolonged bleeding after cut
  • GI bleeding
  • Haematuria
  • Severe epistaxis
  • Haemarthrosis
136
Q

Investigations for Haemophilia

A

Bloods + PT + APTT

Factor 8/9 not extrinsic so:
- PT = normal
- VWF = normal

PROLONGED ACTIVATED PARTIAL THROMBOPLASTIN TIME (intrinsic)

Reduced plasma levels of factor 8/9

137
Q

PT vs APTT

A

PT = Prothrombin time = part of the EXTRINSIC pathway (Warferin + vit K affects)

APTT = activated partial thromboplastin time = INTRINSIC pathway (Heparin affects)

138
Q

Management of Haemophilia

A
  • IV recombinant factor 8/9 concentrate – given as prophylaxis (before and after surgery) or to treat an acute bleeding episode
  • Synthetic vasopressin – IV, s/c or intranasal administration, raises level of factor 8/9
  • Hep A/B vaccinations
  • Encouragement to join exercise regimes and avoid contact sport and aspirin
139
Q

Complications of Haemophilia

A

Joint deformities and arthritis from recurrent bleeding into joints

140
Q

VWF disease - pathophys

A

Autosomal DOMINANT mutation of VWF gene on chromasome 12

Reduced VWF (responsible for basis of platelet plugs) = more spontaneous bleeds/bruising

MOST COMMON inherited bleeding disorder

141
Q

Diagnosis of VWF def

A

Affecting the intrinsic pathway so NORMAL PT but RAISED APTT

Bloods: normal Factors 8/9 (use an assay)
- reduced plasma VWF

142
Q

Treatment of VWF def

A

No cure

DESMOPRESSIN - causes increased release of VWF from endothelial WEIBEL-PALADE BODIES (eleongated secretory organelles specifically in endothelial cells - contain VWF + other proteins for inflam, angiogenesis + tissue repair)

143
Q

Pathophysiology of Disseminated Intravascular Coagulation

A
  • Widespread generation of fibrin at points throughout the vascular system caused by the initiation of the coagulation pathway - typically the extrinsic pathway, starts with tissue factor
  • Consumption of platelets/coag factors
  • Secondary activation of fibrinolysis -> production of Fibrin + Fibrinogen Degredation Products (broken up fibrin) which inhibit fibrin poylmerisation and contribute to bleeding
  • Activation of Tissue Plasminogen activator -> increased fibrinolysis/worse clotting

There is initial widespread thrombus formation throughout blood vessels (causing ischaemia) -> depletion of clotting factors -> increased tendency to bleed

144
Q

Causes of DIC

A

Imbalance between formation of new clots and breaking down old clots
- Anything that causes mass activation of clotting cascade (ie severe inflam states)

  • Malignancy – leukaemia t(15:17) translocation (acute promyelocytic leukaemia)
  • Septicaemia
  • Trauma
  • Infections - meningitis
  • Obstetrics causes
    – amniotic fluid embolism
    • abruptio placentae (detaches from inner wall before delivery)
  • Haemolytic transfusion reactions
  • Liver disease
145
Q

Presentation of DIC

A

Range of presentation from no bleeding to complete haemostatic failure

  • Bleeding - typically from venepuncture/IV sites + nose/mouth
  • Bruising
  • SOB (bleeding into lungs/ischaemia/necrosis)
  • Haemoptysis

Can get ischaemia/necrosis -> organ damage

146
Q

Investigations of DIC

A

Diagnosis suggested by history (severe sepsis, trauma, malignancy), clinical presentation and presence of severe thrombocytopenia

  • Prolonged PTT, APTT and Thrombin Time (TT)
  • Decreased fibrinogen and increased FDPs
  • Blood film – shows schistocytes (fragmented red cells - cut up by excess fibrin strands)
147
Q

Treatment of DIC

A
  • Treat underlying cause – maintain blood volume and tissue perforation
  • May need transfusions – platelets, RBCs and Fresh Frozen Plasma (FFP)
  • Activated C protein (inhibts V and VII -> less clotting)
148
Q

General causes (not specific) of thrombocytopenia

A
  • Reduced platelet production in BM
  • Excess peripheral destruction of platelets
  • Problems of enlarged spleen
149
Q

Types of Thrombocytopenias

A
  • Immune thrombocytopenic purpura (ITP) - MORE COMMON
  • Thrombotic thrombocytopenic purpura (TTP)
150
Q

Epidemiology of ITP + types of ITP

A
  • Type 1: in children 2-6 y/o (acute/primary)
    • often follows viral infection,
    • rapid onset or purpura which is usually self-limiting
  • Type 2: in adults, esp young women (chronic/secondary)
    • usually less acute than in children
    • esp women with malig, HIV, other autoimmune
151
Q

Pathopys of ITP

A

Autoimmune destruction of platelets (IgG antibodies to platelets and megakaryocytes)

  • Often triggered by viral infection or malignancy
  • The IgG antibodies coat the platelets which are then removed by binding to Fc receptors on macrophages
152
Q

Presentation of ITP

A
  • Easy bruising
  • Purpura – red or purple spots on skin caused by bleeding underneath
  • Epistaxis – nose bleed
  • Menorrhagia
  • Gum bleeding

Otherwise systemically well

153
Q

Investigations for ITP

A
  • FBC: Thrombocytopenia – low levels of platelets
  • Increased megakaryocytes on BM examination
  • May have detection of platelet autoantibodies
154
Q

Treatment of ITP

A
  • 1st LINE: Corticosteroids - PREDNISOLONE
  • IV Immunoglobulin (e.g. IV IgG) - Decreases splenic platelet destruction
  • 2nd line: Splenectomy
155
Q

Pathophysiology of TTP

A
  • deficiency in ADAMTS 13 - protease which is normally responsible for VWF degradation
  • Causes extensive microvascular clots to form in small vessels -> low platelet count (due to platelet consumption) + organ damage
156
Q

Epidemiology of TTP

A
  • Adult FEMALES esp with:
    • Malig
    • HIV
    • other Autoimmune
157
Q

Presentation of TTP

A
  • Easy bruising
  • Purpura/PURPURIC RASH
  • menorrhagia
  • AKI
  • (Microangiopathic) haemolytic anaemia (physical damage due to occlusion by fibrin deposition/platelet aggregation)
  • neurological Sx
  • Fever (SYSTEMICALLY UNWELL)
158
Q

Diagnosis of TTP

A
  • FBC:
    • thrombocytopenia
    • normal/increased megakaryocytes
    • Reduced ADAMTS 13
  • Coagulation screen: normal but LDH raised due to haemolysis
  • Blood film: SCHISTOCYTES (fragmented parts of RBCs)
159
Q

Treatment of TTP

A
  • PLASMAPHERESIS/plasma exchange (remove blood through needle/catheter; circulate through machine; plasma is filtered out + altered/discarded -> removes ADAMTS 13 Ab)
  • IV METHYLPREDNISOLONE
  • IV RITUXIMAB
160
Q

Define PT and INR. Normal PT and INR ranges

A
  • PT = coag speed of EXTRINSIC PATHWAY (related to time taken for prothrombin -> thrombin)
    • Normal ~ 10-13.5s
  • INR (international normalised ratio) = patient PT/referance PT
    • ~0.8-1.2
161
Q

When may PT/INR be raised

A
  • If on anticoag
  • Liver disease
  • Vit K deficiency
  • DIC
162
Q

INR if on Warferin

A

2-3

163
Q

Define APTT + give normal range

A
  • APTT (activated partial thromboplastin time) = coagulation speed of INTRINSIC PATHWAYS
    • Normal ~ 35-45s
164
Q

What is APTT raised in

A
  • Haemophilia A + B
  • VWF
    (PT normal in both of above)
  • can be prolonged if on Heparin (it inhibits intrinsic pathway at various points e.g. prothrombin)
165
Q

APTT while on Heparin

A

~60-80s

166
Q

Define G6PDH def

A

X-linked recessive enzymopathy -> halving of RBC life time + degradation

167
Q

Epidemiology of G6PDH def

A
  • X linked so more common in males
  • typically in Mediterranean, African + Middle/Far Eastern ppl
  • Protective against malaria falciparum
168
Q

Pathophys of G6PDH def

A
  • G6PDH catalyses first step in pentosephosphate pathway (makes NADPH).
  • This pathway maintains GLUTATHIONE in reduced state.
  • Glutathione protects RBCs from OXIDATIVE STRESS (i.e ROS like H2O2 which -> haemolysis)
    -in deficiency -> increased haemolysis -> NORMOCYTIC Anaemia
169
Q

Presentation of G6PDH def

A
  • Asymp until exposed to triggering factors that cause oxidative stress
    -> Haemolytic anaemia - Presents with JAUNDICE

Diff types:

  • Neonatal presentation (jaundice)
  • CHRONIC HAEMOLYTIC ANAEMIA
  • Acute haemolysis
    • RAPID ANAEMIA (fatigue, pallor etc)
    • JAUNDICE

Also:

  • BACK PAIN
  • DARK URINE (haemoglobinuria)
170
Q

Triggers of G6PDH def attack

A
  • FAVA BEANS (common in kids)
    • contain GLUCOSIDES which are metabolised to ROS
  • Drugs:
    • quinine, quinalones (antimalarials),
    • sulphonamides (sulphametoxazole, sulphasalazine),
    • NITROFURANTOIN
    • Aspirin
  • Infections
171
Q

Investigations for G6PDH def

A
  • FBC – anaemia and raised reticulocytes (normal if inbetween attacks)
  • Blood film – BITE CELLS (look like bite taken out) and blister cells, Heinz bodies (precipitated denatured haemoglobin in RBCs) (normal inbetween attacks)
  • Enzyme assay (low G6PDH)
172
Q

Management of G6PDH def

A
  • Avoid precipitants (e.g. fava beans, henna)
  • Blood transfusion if/when severe
173
Q

Pathophys of Hereditary Spherocytosis

A

AUTO DOMINANT membranopathy

  • Mutation causes deficiency in STRUCTURAL MEMBRANE PROTEIN - SPECTRIN
    • increases permeability to sodium -> requires increased rate of active transport out of cells
    • makes RBCs more SPHERICAL + RIGID (reduced SA:V ratio)
      • Increased splenic recycling (extravascular haemolysis)
        -> splenomegaly due to rigid cells getting stuck in splenic microcirculation + destroyed
        -> risk of autosplenomegaly (spontaneous infarction -> hyposplenism)
        -> NORMOCYTIC ANAEMIA

Specifically, RBCs lose part of their cell membrane as they PASS THROUGH THE SPLEEN - as lipid bilayer not adequatly structurally supported

174
Q

Epidemiology of hereditary spherocytosis

A

Most common inherited haemolytic anaemia in N Europe + America

175
Q

Presentation of hereditary spherocytosis

A
  • Anaemia symps
  • NEONATAL JAUNDICE
  • SPLENOMEGALY
    • exacerbated during infection
  • GALL STONES (50% - due to excess bilirubin)
  • can get leg ulcers
176
Q

DIagnosis of spherocytosis

A

FBC + blood film:

  • NORMOCYTIC NORMOCHROMIC anaemia
  • Increased RETICULOCYTES
  • SPHEROCYTES
    (-Osmotic fragility test will show fragility in hypotonic solutions)

DIRECT COOMBS TEST = -VE (to rule out AHA)

177
Q

Treatments for her spherocytosis

A
  • SPLENECTOMY(as the main damage + destruction to RBCs occurs as they are going through the spleen)
    • wait till at least 6y/o due to sepsis risk (spleen fights off encapsulated bacteria)
    • Requires lifelong penicillin prophylaxis post-op
  • folate supps
  • transfusions

For neonatal jaundice:
- PHOTOTHERAPY (conjugates bilirubin)
- risk of KERNICTERUS if untreated (bilirubin accumulation in basal ganglia)

178
Q

Pathophys of Autoimmune haemolytic anaemias

A

Can either be warm or cold subtype depending on what it is precipitated by.

Auto Ab bind RBCs -> intra/extravasc haemolysis

179
Q

Presentation of AHA

A
  • anaemia
  • potential jaundice
  • splenomegaly
180
Q

Diagnosis of AHA

A

FBC + Blood film:
- NORMOCYTIC NORMOCHROMIC anamia
- increased reticulocytes
- oft see SPHEROCYTES

DIRECT COOMBES +VE (agglutination of RBCs w/ Coomb reagent)
- diff from spherocytosis which is coombs -ve

181
Q

Tumour lysis syndrome

A

Oncologic emergency caused by massive tumor cell lysis with the release of large amounts of potassium, phosphate, and nucleic acids into the systemic circulation

Can cause renal AKI/failure as uric acid, calcium phosphate or hypoxanthine can precipitate in tubules -> Acute tubular necrosis
-> electrolyte disturbances -> arrhythmias, siezures etc

182
Q

Define sideroblastic anaemia

A

Oft X LINKED inherited ALA synthetase deficiency -> FUNCTIONAL Fe DEFICIENCY due to DEFECTIVE Hb synthesis in the MITOCHONDRIA

Can also be due to B6 deficiency

  • Fe is raised but is not used in Hb synth so becomes trapped in mitochondria
183
Q

Diagnosis of Sideroblastic anaemia + treatment

A

FBC + Blood film:
- MICROCYTIC
- RINGED SIDEROBLASTS
- BASOPHILIC STIPPLING (increased granules)

Fe studies:
- raised serum iron
- raised serum ferritin
- raised transferrin saturation
- Decrease Total Iron Binding Capacity

Tx:

  • Pyridoxine (vit B6), thiamine/folate supps
  • Blood transfusion
  • Desferroxamine chelation for overload
184
Q

RFx of Hodgkin’s lymphoma

A
  • Age 20-34 years AND >55 years
    • esp young adults from higher socio-economic class
  • EBV INFECTION
  • FHx
  • certain HLA types (tho no HLA class 2 expression has been associated with adverse prognosis)
  • Jewish ancestry
185
Q

Felty syndrome

A

Rare, potentially serious

Define by presence of triad:

  • RA
  • splenomegaly
  • neutropenia -> repeated infections

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