Renal pathology

Question 1

What is the functional unit of the kidney?

Answer 1

Nephron

Question 2

What does the nephron consist of?

Answer 2

Renal corpuscle (glomerulus w/ Bowman’s capsule)
PCT
Loops of Henle
Distal tubules
Collecting ducts

Question 3

Discuss the clinical presentation of patient’s with renal disease

Answer 3

Proteinuria (nephrotic syndrome)
Haematuria (nephritic syndrome)
Systemic hypertension
Renal failure
UTIs
Nephrolithiasis
Renal tubular defects

Question 4

What is proteinuria?

Answer 4

> 30mg/24h (adults)
100mg/m2/24h (children)

Question 5

What are features of nephrotic syndrome?

Answer 5

Heavy proteinuria (>3.5g/24h)
Generalised edema
Hypoalbuminemia
Hyperlipidemia

Question 6

What are the types of haematuria?

Answer 6

Macroscopic vs microscopic
Intermittent vs persistent

Question 7

What are non-haematuria causes of red urine?

Answer 7

Foods (beets, blackberries, rhubarb)
Medications (rifampicin, laxatives)
Poisons (lead, mercury)

Question 8

What is the pathophysiology of haematuria?

Answer 8

Glomerular disease -> dysmorphic RBCs in urine

Question 9

What are the features of nephritic syndrome

Answer 9

Acute onset haematuria
Oliguria
Systemic hypertension
+/- peripheral edema
+/- proteinuria

Question 10

What are the pathogenetic mechanisms of glomerular inflammation?

Answer 10

Majority are immune mediated
- immune complex formation and deposition
- non immune complex mediated (lymphokines, cytokines)

Question 11

What kinds of antigens are involved in antigen-antibody complex formation?

Answer 11

Planted antigens
Fixed antigens

Question 12

Which primary renal diseases result in nephrotic syndrome?

Answer 12

Minimal change disease
Focal segmental glomerulosclerosis
Membranous glomerulosclerosis
Membranoproliferative glomerulosclerosis

Question 13

Which primary renal diseases result in nephritis syndrome?

Answer 13

Diffuse proliferative
Mesangioproliferative
Thin basement membrane disease
Anti-GBM disease
Focal segmental proliferative

Question 14

Which systemic diseases involve the renal system?

Answer 14

DM
SLE
Amyloidosis
Infections (HIV, malaria, hepatitis)
Drugs (heroin)

Question 15

What is the most common cause of nephrotic syndrome in children?

Answer 15

Minimal change disease

Question 16

What is minimal change disease associated with? (minority of cases)

Answer 16

Infections
Immunisation
Drugs
Neoplasia

Question 17

Discuss the aetiology of minimal change disease

Answer 17

Immunologic (lymphokine/cytokine)
Not immune-complex mediated

Question 18

Discuss clinical features of minimal change disease

Answer 18

Caucasian > black
M > F
Proteinuria
Responsive to steroids

Question 19

How does minimal change disease appear on histology?

Answer 19

Light microscopy - normal
IF microscopy - normal
Epithelial cell foot process effacement on ultrastructural examination

Question 20

What is the epidemiology of focal segmental glomerulosclerosis with hyalinosis?

Answer 20

Adult > children in NS
Black patients
Increasing with HIV

Question 21

Discuss the aetiology of focal segmental glomerulosclerosis

Answer 21

Lymphokine/cytokine
Not immune-complex mediated

Question 22

How does focal segmental glomerulosclerosis appear on histology?

Answer 22

Focal lesions (<50% glomeruli involvement)
Segmental lesions
Loss of capillary loop patency
Glomerular tuft sclerosis
Epithelial cell foot process effacement

Question 23

What is the prognosis of focal segmental glomerulosclerosis?

Answer 23

Poor response to steroids
50% progress to chronic renal failure
Disease recurs in renal transplants

Question 24

Discuss the aetiology of membranous glomerulnephritis

Answer 24

Immune-complex mediated
Ag-Ab complex deposition in relation to glomerular BM (sub-epithelial)

Question 25

Name causes of membranous glomerulonephritis

Answer 25

85% idiopathic (primary) Infections Drugs Tumours Auto-immune disease

Question 26

Name infectious causes of membranous glomerulonephritis

Answer 26

HBV Malaria Syphilis Bilharzia

Question 27

Name toxin causes of membranous glomerulonephritis

Answer 27

Gold Mercury Heroin

Question 28

Name neoplastic causes of membranous glomerulonephritis

Answer 28

Carcinoma Melanoma Lymphoma

Question 29

Name auto-immune disease causes of membranous glomerulonephritis

Answer 29

SLE

Question 30

Discuss the features of membranous glomerulonephritis on histology

Answer 30

Glomerular BM changes - diffuse spike formations - subepithelial deposits No cellular proliferation

Question 31

Discuss the prognosis of membranous glomerulonephritis

Answer 31

Adults - majority unresponsive to therapy and progress to chronic RF Children - better prognosis, 10% to chronic RF

Question 32

Discuss the aetiology of membranoproliferative glomerulonephritis

Answer 32

Immune-complex mediated Ag-Ab complex deposition in relation to glomurular BM (sub endothelial) and within the mesangium

Question 33

What is the difference in the Ag-Ab complexes in membranous glomerulonephritis and membranoproliferative glomerulonephritis

Answer 33

Membranous - subepithelial Membranoproliferative - subendothelial

Question 34

Discuss the features of membranoproliferative glomerulonephritis on histology

Answer 34

Diffuse proliferative process Crescentic Distinctive glomerular BM changes - increased mesangial cellularity - double contour 'tram tracks'

Question 35

Discuss the prognosis of membranoproliferative glomerulonephritis

Answer 35

Poor Majority progress to CF

Question 35

Discuss the aetiology of post-infectious glomerulonephritis

Answer 35

Diffuse proliferative glomerulonephritis Ag-Ab complex deposition following a transient infection

Question 36

Which organisms can result in post-infectious glomerulonephritis?

Answer 36

Bacteria - BHS - staph - meningo - pneumo Viruses Malaria Bilharzia Toxoplasmosis

Question 37

Discuss the features of post-infectious glomerulonephritis on histology

Answer 37

Diffuse proliferative glomerulonephritis Large subepithelial humps

Question 38

What is the prognosis of post-infectious glomerulonephritis?

Answer 38

Generally good

Question 39

What is mesangioproliferative glomerulonephritis?

Answer 39

A heterogeneous group of diseases including SLE and IgA nephropathy

Question 40

Discuss the causes of mesangioproliferative glomerulonephritis

Answer 40

Majority = idiopathic Autoimmune (SLE) Infectious (HBV, bilharzia) Drugs Neoplasm (carcinoma, malignant, lymphoma)

Question 41

What are the 3 main kidney lesions in HIV renal disease?

Answer 41

HIV associated nephropathy (HIVAN) HIV immune complex kidney disease (HIVICKD) Thrombotic microangiopathy

Question 42

What are the histological features of thrombotic microangiopathy?

Answer 42

Intimal swelling Arteriolar thrombi Fibrinoid material in vascular lumina

Question 43

Which genes are implicated in HIVAN?

Answer 43

APOL1 MYH9 (African descent)

Question 44

Discuss the clinical presentation of HIVAN

Answer 44

Acute onset proteinuria Progressive renal insufficiency Hypoalbuminemia Minimal peripheral edema BP normal Enlarged kidneys

Question 45

Discuss the histological features of HIVAN

Answer 45

Pan-nephropathy (collapsing variant of FSGS) Microcystically dilated tubules Interstitial inflammation and fibrosis

Question 46

What is the prognosis of HIVAN?

Answer 46

Poor

Question 47

In which amyloidosis types is renal involvement common?

Answer 47

AL AA

Question 48

Discuss the histological features of amyloidosis

Answer 48

Extracellular deposits within the glomerulus, around blood vessels and within interstitial

Question 49

Discuss the pathogenesis of diabetic glomerulopathy

Answer 49

Increased GMB permeability -> excess collagen IV deposition -> protein glycosylation -> hyperinfiltration

Question 50

Discuss the histological features of diabetic glomerulopathy

Answer 50

Capillary wall thickening Mesangial expansion Kimmelstiel Wilson lesion