L77 - Kidney Diseases II Flashcards Preview

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Flashcards in L77 - Kidney Diseases II Deck (91):
1

What are the 2 major groups of processes in renal tubule diseases?

1) Acute tubular injury and acute renal failure

2) Tubulointerstitial nephritis

2

What is Acute tubular injury and acute renal failure mostly due to?

Ischaemic or toxic injury

3

What is Tubulointerstitial nephritis mostly caused by?

Inflammatory reactions of tubules and interstitium

4

What is another name for acute tubular injury?

Acute tubular necrosis

5

How does acute tubular injury present?

As Acute renal failure

Tubular injury is the most common cause of acute renal failure

6

Describe acute renal failure?

Clinicopathologic entity with clinical acute deterioration of renal function

Associated with morphologic evidence of tubular injury

7

Give 3 examples of ischaemia that causes acute renal failure?

Decreased effective circulating blood volume (e.g. shock)

Diffuse involvement of intrarenal blood vessels (e.g. malignant hypertension)

Thrombosis (e.g. thrombotic microangiopathy)

8

Give examples of direct toxic injury that causes acute renal failure?

drugs
Radiocontract dyes
heavy metals
Organic solvents

9

Give 3 examples of urinary obstruction that causes acute renal failure?

By prostatic hypertrophy

Tumour

Blood clot

10

Apart from ischaemia, urinary obstruction, direct toxic injury, name one cause of acute renal failure?

Acute Tubulointerstitial nephritis

11

[Acute tubular injury appearance under light microscopy?

Necrotic tubular epithelium sloughed in tubules

Dilated tubules with flattened tubular epithelium

12

3 stages of acute tubular injury?

Initiation phase

Maintenance phase

Recovery phase

13

What is initiation phase in acute tubular injury?

Slight decline in urine output with rise in blood urea and creatinine

(lasting for about 36 hours)

14

What is maintenance phase in acute tubular injury?

Decrease in urine output 40-400 mL/day (oliguria),

salt and water overload,

rising blood urea and creatinine,

hyperkalemia

metabolic acidosis

15

What is Recovery phase in acute tubular injury?

Steady increase in urine volume, up to 3L/day,

leading to loss of large amount of water, sodium and potassium

16

What is the outcome in acute tubular injury?

supportive care >> most patients can recover

17

What can delay recovery in acute tubular injury?

conditions like sepsis, extensive burns and multi-organ failure

18

What is affected in Tubulointerstitial nephritis?

• Inflammatory injuries of the tubules AND interstitium

• Glomeruli are spared

19

How does acute Tubulointerstitial nephritis manifest?

presented as acute or
subacute worsening of renal function:

• Raised blood urea and creatinine level
• Usually 2 weeks after drug exposure

20

What is the number 1 cause of Tubulointerstitial nephirits?

Drugs

21

What are other causes of Tubulointerstitial nephritis?

• Infections
• Metabolic diseases
• Neoplasm
• Physical factors
• Immunologic reactions

22

What infections can cause Tubulointerstitial nephritis?

Acute and Chronic pyelonephritis

23

What Metabolic diseases can cause Tubulointerstitial nephritis?

Nephropathy:
1) Urate
2) Acute phosphate
3) Hypokaelemic
4) Oxalate
5) Acute phosphate

+ nephrocalcinosis

24

What neoplasms can cause Tubulointerstitial nephritis?

• Multiple myeloma (light chain cast nephropathy)

25

What physical factors can cause Tubulointerstitial nephritis?

Chronic urinary tract obstruction

26

What immunologic reactions can cause Tubulointerstitial nephritis?

Sarcoidosis, Sjogren’s disease

27

What are the top causative drugs causing tubulointestinal nephritis?

All drug classes

Especially NSAID, Antibiotic, Antivirals, Diuretics

28

WHat reaction occurs that cause tubulointerstitial nephrritis? How to allevaite problems?

Hypersensitivity reaction to medication

Identification and withdrawal of the culprit drug

29

3 histology features of Tubulointestinal nephritis?

• Interstitial inflammation
>>Abundant eosinophils points to drug cause

• Tubulitis
>> Inflammatory cells in between tubular cells

• Interstitial edema (acute) or fibrosis (chronic)

30

Light microscopy appearance of drug-induced acute tubulointerstitial nephritis?

Large amount of inflammatory cells including eosinophils (stained red) in the interstitium and tubulitis

edema

31

What does Pyelonephritis affect?

tubules, interstitium and renal pelvis

32

2 major forms of pyelonephritis?

• Acute pyelonephritis
• Chronic pyelonephritis

33

What is acute pyelonephritis? Caused by?

• Acute infection of kidney, generally caused by ascending bacteria infections

34

2 routes of acute pyelonephritis?

• Acute pyelonephritis
• Chronic pyelonephritis

35

What are some common predisposing causes of acute pyelonephritis?

• Lower urinary tract infection
• Urinary tract obstruction
(Stones/tumour)
• Vesico-ureteric reflux

36

What are some less common predisposing causes of acute pyelonephritis?

• Pregnancy
• Instrumentation / catheterization of urinary tract
• Immunosuppression and
deficiency

37

What are some presenting symptoms of acute pyelonephritis?

Fever
Loin pain
Shaking chills
Nausea
Vomiting
Diarrhoea

38

What is a presenting symptoms of acute pyelonephritis Specific to bhildren?

Failure to thrive

39

Name the common pathogens that cause Acute pyelonephritis?

• Mycobacterium Tuberculosis (TB) ***
• Other bacteria and fungal infections

40

What are other bacteria (not Mtb) that can cause acute pyelonephritis?

• Escherichia coli (E. coli)
• Proteus
• Klebsiella
• Enterobacter
• Strptococcus faecalis
• Staphylococcus

41

Gross appearance of urinary tract of acute pyelonephritis?

Multifoci abscess and pus formation

42

Light microscopic appearance of urinary tract of acute pyelonephritis?

Glomerulus preserved
(infection extend up to Bowman's capsule)

Large amount of neutrophils in interstitium and tubules + other inflammatory cells

43

Treatment of acute pyelonephritis?

appropriate antibiotic therapy depending on the inciting pathogen

44

Outcome of acute pyelonephritis?

• Symptoms usually disappear in a few days

• Usually complete resolution without leaving significant effects on kidney
function

45

Describe the healing process of acute pyelonephritis?

• Neutrophilic infiltrates replaced by macrophages, plasma cells and
lymphocytes
• Scattered scar formation

46

Name 2 complications of acute pyelonephritis?

• Pyelonephrosis
>> Pus in renal pelvis, calyces and ureter


• Perinephric abscess
>> Extension of pus through renal capsule into perinephric tissue

47

Describe chronic pyelonephritis?

Chronic inflammation in tubules and interstitium (Tuberculosis excluded)

>> Scarred kidney caused by repeated bacterial infections

48

What is chronic pyelonephritis associated with?

• Vesico-ureteric reflux
• Urinary tract obstruction (stone, stricture)

49

Is Chronic pyelonephritis bilateral or unilateral?

• Involvement usually unequal on the two sides

50

How does the scar formation in chronic pyelonephritis change the morphology of kidney?

Scar tissue is depressed/ shrunken

51

Symptoms of recurrent acute pyelonephritis?

• High fever
• Shaking chills
• Loin pain

52

What are the early stage symptoms of chronic pyelonephritis?

subtle/no symptoms in early stage

>> Polyuria and nocturia due to loss of tubular function in concentrating urine and resorption of water

53

Name one symptom of chronic renal failure and end stage kidney disease?

Uraemia

54

Explain how chronic pyelonephritis lead to FSGS?

FSGS = nephrotic

• Decrease in number of functional glomeruli due to loss of nephron unit

• Compensatory hypertrophy by remaining glomeruli (due to increased renal blood pressure)

• Progressive fibrosis involving portions of some glomeruli due to compensatory action >. FSGS

55

Are microscopic findings diagnostic for chronic pyelonephritis?

No

56

Treatment for chronic pyelonephritis?

• Treat possible underlying causes
• Treat recurrent acute pyelonephritis by antibiotic therapy

57

Outcome of Chronic pyelonephritis?

• Depends on extent of scarring:

If loss of significant amount of renal tissue = End stage renal disease

58

What is the Dx for this case:

35/F
Unknown herbal medicine intake
Epigastric pain and vomiting with oligouria

Normal kidney size and WBC levels

Tubulointerstitial nephritis?

Need microscopy to diagnose

59

What are the microscopic features of light chain cast nephropathy?

Tubular casts rimmed by
macrophages revealed by both PAS stain and H&E stain

Lambda light chain restriction



60

What is Lambda light chain restriction?

In reactive lymphoid populations there is a mixture of kappa and of lambda positive cells,

>> cells expressing kappa light chains outnumbering cells expressing lambda light chains >> lambda light chain restriction

61

What is the cause of light chain cast nephropathy?

Neoplasm > multiple myeloma = neoplasm of plasma cells

62

What age group does light chain cast nephropathy affect?

90% of cases greater than age of 50 years old (median age 70 years old)

63

Presentation of Light chain cast nephropathy?

Acute renal failure and proteinuria

64

Other renal diseases associated with monoclonal light chains?

• Amyloidosis (AL type)
• Light chain deposition disease
• Light chain proximal tubulopathy

65

Treatment for Light chain cast nephropathy?

• Treat underlying plasma cell neoplasm
• Hematopoietic stem cell transplantation in selected case

66

Outcome of Light chain cast nephropathy?

• 5-year survival rate: 20-25%

67

Name 4 important vascular diseases that lead to renal disease?

* only remember top 4*

• Hypertensive nephrosclerosis
• Malignant nephrosclerosis (malignant hypertension)
• Diabetic nephropathy
• ANCA-associated vasculitis

(Atheroemboli, Renal artery stenosis, Thrombotic microangiopathy)

68

Diabetic nephropathy affects which structures?

Affecting both vessels and glomeruli

69

Pathology of Hypertensive nephrosclerosis causing Extravasation of plasma protein ?

Hypertension >> Sclerosis of renal arterioles and small arteries

>> Hyalinization of arteriolar wall

>> Extravasation of plasma protein through injured endothelium

70

Changes to renal arterioles in Hypertensive nephrosclerosis?

Intimal fibrosis and medial thickening

71

How does Hypertensive nephrosclerosis lead to gradual decline in renal function?

Affected vessels have thickened walls and narrowed lumens

>> ischaemia and subsequent glomerulosclerosis and chronic tubulointerstitial injury

>> gradual decline in renal function

72

Light microscopy appearance of Hypertensive Nephrosclerosis? **important**

Glomerulus:
Glomerulosclerosis and Hyaline arterolosclerosis

Arterioles:
Intimal fibrosis and medial
thickening of artery

73

What is Malignant nephrosclerosis associated with?

• Associated with malignant or accelerated hypertension

74

What is the criteria for malignant hypertension?

Systolic pressure greater than 200 mmHg and/or diastolic pressure
greater than 120 mmHg

75

Presentation of malignant nephrosclerosis?

acute renal failure

Papilloedema (optic disc swelling), retinal haemorrhages,

encephalopathy, cardiovascular
abnormalities

76

Light microscopic appearance of Malignant nephrosclerosis?

• Fibrinoid necrosis of arteriole
• Hyperplastic arteriolitis (onion-skin lesion)

77

Treatment of malignant nephrosclerosis?

• Prompt and aggressive antihypertensive medication

78

Which type of diabetes can lead to diabetic nephropathy?

• Both Type I and Type II Diabetes mellitus (DM)

79

3 histological features of Diabetic nephropathy on the glomeruli?

• Thickened GBM (increase ground substance)

• Diffuse increase in mesangial matrix

• Kimmelstiel-Wilson nodules (deposition of basement membrane nodules)

80

How does Diabetic nephropathy lead to gradual decline in renal function?

Leading to ischaemia and subsequent glomerulosclerosis

> chronic tubulointerstitial injury > gradual decline in renal function

81

What forms in renal vasculature?

Leading to ischaemia and subsequent glomerulosclerosis and chronic tubulointerstitial injury

82

histological features of Diabetic nephropathy on the renal arterioles?

Hyalinosis of both afferent
and efferent arterioles

83

What is the EM appearance of GBM in Diabetic nephropathy?

GBM thickened to more than 1000nm, at least twice as thick as GBM

84

What type of glomerulonephritis is caused by ANCA-associated vasculitis?

rapidly progressive (crescentic) glomerulonephritis

Type III, Pauci-immune

85

Why is ANCA-associated vasculitis Pauci-immune?

Lack of detectable anti-GBM antibodies or immune complex

by direct immunofluorescence and electron microscopy

86

Name the 2 circulating antibodies in ANCA-associated vasculitis?

• c-ANCA (cytoplasmic)
• p-ANCA (perinuclear)

87

What is the full name of ANCA?

antineutrophil cytoplasmic antibodies

88

What are the 2 disease entities of ANCA-associated vasculitis?

granulomatosis with polyangiitis

Microscopic polyangiitis

89

What replaces vessel walls in ANCA- associated vasculitis?

Fibrin

90

Pathology of ANCA-associated vasculitis?

Injury to glomerular tufts >> leakage of plasma protein stimulates Bowman’s
capsule

>> parietal epithelium proliferates

>> hypercellular glomeruli
with crescentic glomerulonephritis

91

Summarize the 3 selected diseases affecting mainly renal blood vessels?

- Hypertensive (and malignant) nephrosclerosis
- Diabetic nephropathy
- ANCA-associated vasculitis

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