NEPHROLOGY

Question 1

WHAT IS GLOMERULONEPHRITIS?

Answer 1

Inflammation of nephrons and glomerulus due to an infection where the antigen-antibody complexes attack the nephrons.

> can be sudden (acute) / gradually (chronic)

Question 2

WHAT IS NEPHRITIS?

Answer 2

LEAK OF RED BLOOD CELLS + MILD PROTEINS 
> hematuria 
> oligouria > less urine volume 
> azotemia - elevation in blood urea nitrogen + serum creatinine levels 
> arterial hypertension

Question 3

WHAT IS NEPHROSIS?

Answer 3

> HEAVY PROTEINURIA > 3.5g/day
hypoalbuminemia
hyperlipidemia
edema

Question 4

OUTLINE MORPHOLOGICAL PHASES OF GLOMERULAR INJURY?

Answer 4

> EXUDATIVE PHASE
PROLIFERATIVE PHASE
SCLEROTIC PHASE OF INFLAMMATORY PROCESS

Question 5

OUTLINE INJURY MECHANISM FOR GLOMERULONEPHRITIS?

Answer 5

1. IMMUNE COMPLEX ASSOCIATED INJURY

2. INJURY ASSOCIATED WITH ANTIBODY TO GLOMERULAR BASEMENT MEMBRANE

Question 6

DESCRIBE IMMUNE COMPLEX ASSOCIATED INJURY TO NEPHRONS?

Answer 6

> presence of antigen-antibody complexes
circulating in blood or in situ of glomerulus
in situ complexes formed when Ab directed at glomerular Ag or foreign bodies + get trapped in glomerulus&raquo_space; SLE
Ag-Ab complexes entrapped + precipitates in glomerular basement membrane

Question 7

DESCRIBE INJURY ASSOCIATED WITH ANTIBODY TO GLOMERULAR BASEMENT MEMBRANE

Answer 7

> Ab directed against Ag of basement membrane
Ab reacts with Ag
this is seen with immunofluroscent staining for IgG
Ab + Ag reaction > activates inflammatory mediators
inflammation > glomerular injury
godpasteurs syndrome

Question 8

WHAT IS GODPASTEURS SYNDROME

Answer 8

> group of acute illnesses affecting lungs + kidneys
autoimmune disorder
immune system > antibodies attack lungs + kidneys
GLOMERULONEPHRITIS
PULMONARY HEMORRHAGES
ANTIGENS ATTACKING ALVEOLAR BASEMENT MEMB.

Question 9

OUTLINE MEDIATORS OF GLOMERULAR DAMAGE?

Answer 9

1. COMPLEMENT 
> role of inflammatory process 
> activated by immune complexes 
> attract neutrophil polymorph 
> increase vascular permeability 
> membrane damage 

2. POLYMORPHONUCLEAR LEUKOCYTES
   > attracted by C5a
   > bind to complexes by C3 + FC receptors
   > release lysosomes in response to trapped complexes
   > further increase damage to glomerular basement memb

3. CLOTTING FACTORS
> mediate glomerular damage 
> fibrin - entraps platelets due to C3 + FC receptors
> micro thrombi formation 
> degranulation 
> release of vasoactive peptides 
> increase vascular permeability

Question 10

OUTLINE MORPHOLOGICAL DIAGNOSTICS FOR GLOMERULONEPHRITIS

Answer 10

1. Ab tagged with fluorochrome
   - localise immuinoreactants in glomerulus
2. Ultrastructural studies
   - position of immune complexes
   - basement membrane reactions
   - epithelial changes
3. Renal biopsy
   - light microscopy > 20 glomeruli
   - immunofluorescence > 5 glomeruli
   - electron microscopy > 2 glomeruli
4. Glomerular hypercellularity
5. Podocytes
   - intracapillary > mesangium + endothelium
   - intercapillary > mesangium
   - extracapillary > bowmans capsule
6. Thickening of glomerular capillary loops
   - deposition of immune complexes
   - increase GBM material
   - infiltrate abnormal materials - amyloid
7. Basement membrane immune deposition
   - sub epithelial
   - intramembranous
   - sub endothelial
8. Hyalinosis
9. Sclerosis/ Collagenous scarring
   - irreversible damage due to chronic process

Question 11

WHAT POST-STREPTOCOCCAL GLOMERULONEPHRITIS

Answer 11

> 10-14 days after upper respiratory infection w/ nephritic strains of beta hemolytic streptococci.

Question 12

DESCRBINE PATHOGENISIS OF POST-STREPTOCOCCAL GN?

Answer 12

> immune complexes of strept. Ag-Ab
> circulate in blood 
> deposit in glomeruli 
OR 
> immune complexes formed in situ from bacterial Ag that are trapped in glomeruli

Question 13

OUTLINE CLINICAL MANIFESTATIONS OF POST-STREPTOCOCCAL GN?

Answer 13

> most common in children 
> proteinuria 
> hematouria 
> hypoalbuminemia 
> edema 
> hypertension 
> renal failure 
>> leading to slow progression of chronic glomerulonephritis or rapid progression of progressive glomerulonephritis

Question 14

DESCRIBE MICRO OF POST-STREPTOCOCCAL GN?

Answer 14

> diffuse + inflammation of glomeruli
enlarged + hypercellular glomeruli
> due to proliferation of mesengial cells + inflammatory inflitration of neutrophils + macrophages

Question 15

DESCRIBE ELECTRON MICROSCOPY OF POST-STREPTOCOCCAL GN?

Answer 15

> inflammatory cells appear in capillaries attached to basement membrane
osmophilic dense deposits of immune complexes
> form large humps on subepithelium