Karnataka PGET Pediatrics MCQ Answer 01

Acute Post Infectious Glomerulonephritis (also called endocapillary glomerulonephritis)

• Nephritic syndrome is classical presentation

1. hematuria
2. proteinuria
3. RBC casts
4. edema
5. decrease in renal function
6. HTN
7. Pulmonary edema and CHF can occur
8. Usually low C3 normal C4
9. ASO elevated (anti strep antibody)

• affects mainly children and young adults (Male:Female 2:1)

• Usu. preceding history of: pharyngitis, tonsilitis, mastoiditis, peritonsillar abscess, or otitis media, or skin infections
• OFFENDING ORGANISM IS USUally: GROUP A STREPTOCOCCUS type 12,4,1, or 49 (nephritogenic strains)
• Following initial strept infection, latent period of 1 – 4 weeks before symptoms appear
• self-limiting disease

Pathology

• LM

1. all glomeruli involved usu to the same degree

2. most characteristic change: diffuse cellular proliferation
3. PMNs are frequently seen (exudative change)
4. cresent formation and capsular adhesions may be present
5. tubule and BV are generally unaffected

• IF

1. IgG and C3 in virtually all glomeruli
2. coarsely granular – lumpy-bumpy

• EM

1. variable #s of electron dense deposits in a subepithelial location in the BMs.
2. the deposits are large hump-like and correspond to the lumpy-bumpy depositis seen on IF
3. PMNs in the capillary lumens

Outcome of Acute Post-infectious glomerulonephritis

• self-limiting
• most cases – kidney returns to normal, patients recover completely
• in smaller number of cases two possibilities exist

1. Complete renal failure

1. 5% of patients
2. characterized by cresent formation in most of the glomeruli
3. CALLED: RAPIDLY PROGRESSIVE GLOMERULONEPHRITIS (other causes of this also)

2. Chronic or latent stage

1. some undergo clinical recovery, but have some abnormality, ex. slight proteinuria, HTN
2. may go into end stage renal disease after several years
3. Renal biopsy: slight persistent mesangial cellularity and increase in mesangial matrix
4. overall prognosis in children better than in adults

Category: Karnataka PGET 2007 MCQs