Case One PART TWO

Question 1

Acute Nephritic Syndrome

Answer 1

1. Poststreptococcal Glomerulonephritis
2. Subacute Bacterial Endocarditis
3. Lupus Nephritis
4. Antiglomerular Basement Membrane Disease
5. IgA Nephropathy
6. ANCA Small Vessel Vasculitis
   a. Granulomatosis with Polyangiitis (Wegener’s)
   b. Microscopic Polyangiitis
   c. Churg - Strauss Syndrome
7. Membranoproliferative Glomerulonephritis
8. Mesangioproliferative Glomerulonephritis

Question 2

Acute endopapillary proliferative glomerulonephritis - POSTSTREPTOCOCCAL GLOMERULONEPHRITIS (prototype)

Answer 2

• incidence decreased in developed countries (only sporadic) - more typical in ELDERLY
• underdeveloped countries
• usually affects CHILDREN between 2 and 14 yo
• MALES
• Familial/cohabitant incidence is 40%
• Skin and throat infection w/ particular M types of streptococci antedate glomerular disease
  
  • M types ff IMPETIGO: 2, 47, 49, 55, 57, 60
  • M types ff PHARYNGITIS: 1, 2, 3, 4, 12, 25, 49

-immune-mediated disease
-involves: 1. Putative strep antigens
2. Circulating immune complexes
3. Activation of complement
-rarely requires renal biopsy
-Tx: Supportive - control of HPN, edema, dialysis
Antibiotic tx for strep infxn
-Good prognosis
*within 3-6 wks - complete resolution of hematuria and proteinuria

Question 3

PGN d/t PGN d/t IMPETIGO develops

PGN d/t PHARYNGITIS

Answer 3

PGN d/t IMPETIGO - develops 2-6 weeks after skin infxn

PGN d/t PHARYNGITIS - develops 1-3 weeks after skin infxn

Question 4

Renal biopsy in PGN

Answer 4

1. Hypercellularity of mesangial and endothelial cells
2. Glomerular infiltrates of polymorphonuclear leukocytes
3. Granular subendothelial immune deposits of IgG, IgM, C3, C4, C5-9, and subepithelial deposits (appear as “humps”)

Question 5

Candidate antigens of PGN

Answer 5

1. Streptococcal Pyrogenic Exotoxin B (SPEB)
   - cationic cysteine proteinase
   - generated by proteolysis of a zymogen precursos (zSPEB)
   - demonstrated inside the subepithelial “humps” on biopsy
2. Nephritis-associated plasmin receptor (NAPIr)

Question 6

Acute nephritic picture

Answer 6

1. Hematuria
2. Pyuria
3. RBC casts
4. Edema
5. HPN
6. Oliguric RF

Systemic s/s: (50% of cases)

1. Headache
2. Malaise
3. Anorexia
4. Flank pain

5% of children and 20% of adults have proteinuria in the nephrotic range
90% of patients - depressed CH50 and decreased levels of C3 with normal levels of C4