TOPIC 6: acute nephritic syndrome

Question 1

basic principles of acute nephritic syndrome & biopsy findings

Answer 1

glomerular diseases characterised by glomerular inflammation and bleeding:

1) limited proteinuria <3.5g/day
2) oliguria & azotemia (dec GFR)
3) salt retention with periorbital edema and hypertension (inc BP)
4) RBS casts and dysmorphic RBCs in urine

biopsy:

• hypercellular and inflamed glomeruli
• immune complex deposition activates the complement
• C5a attracts neutrophils which mediates damage

Question 2

pathophysiology of ANS

Answer 2

The lesions that cause the nephritic syndrome have in common:

• proliferation of cells within the glomeruli
• often accompanied by inflammatory leukocytic infiltrate
• this inflammatory reaction severely injures the capillary walls, permitting blood to pass into the urine and inducing hemodynamic changes that lead to reduction in the GFR (oliguria, fluid retention & azotemia)
• HTN is a result of both the fluid retention and the augmented renin release from the ischemic kidneys

Question 3

Causes of ANS

Answer 3

Maybe a manifestation of systemic disorders (SLE) or may follow a primary glomerular disease (IgA nephropathy)

1) Poststreptococcal glomerulonephritis (PSGN)
2) rapidly progressive glomerulonephritis
- goodpasture syndrome
- diffuse proliferative glomerulonephritis or PSGN
- Wegener’s gran / microscopic polyangitis /Churg-strauss sy
3) IgA nephropathy
4) Alport syndrome

Question 4

ANS: poststreptococcal glomerulonephritis

symp& treat

Answer 4

• nephritic syndrome that arises after group B-hemolytic strep (strains with M-proteins) infection of SKIN or PHARYNX
• presents 2 weeks after the infection and is more common in children but can also occur in adults

1) cola colored urine (hematuria)
2) oliguria
3) HTN
4) periorbital edema

• hypercellular, inflammed glomeruli
• mediated by immune complex deposition
• subepithelial ‘humps’ bec complexes start endothelialy and move up subepithelialy & pile up
• serology: increased ASOT & C3

RENAL BIOPSY NOT DONE USUALLY

treatment:

• supportive (> 95 % recover)
• children rarely progress to RF
• Adults (25%) develop RPGN

Question 5

ANS: IgA Nephropathy ( BERGER DISEASE)

Answer 5

• IgA Immune complex deposition in mesangium of glomeruli (SHOWN ON BIOPSY)
• most common nephropathy worldwide
• presents in childhood with episodic gross or microscopic hematuria with RBC casts usually following mucosal infections e.g gastroenteritis
• may slowly progress to RF( 20% adults develop ESRF over 20 years)
• treatment is BP control with ACEi
• immunosuppression may slow decline of renal function

-typical patient is a young man with episodic macroscopic hematuria. Recovery is rapid between attacks

Question 6

ANS: Alport syndrome

Answer 6

• inherited defect in typeIV collagen; most commonly X linked
• thinning and splitting of the glomerular basement membrane
• isolated hematuria, sensory hearing loss and occular disturbances.