poststreptoccal glomerulonephritis
TRANSCRIPT
Poststreptococcal Glomerulonephritis
Nirav Dhruva
Morning Report
July 2005
Poststreptococcal GN (Introduction) Usually occurs 10 days
after pharyngitis and 14 days after skin infection
(not synpharyngitic) Fallen incidence in US,
but common in some rural areas, poor hygiene places, and tropical countries
Occurs more often in males and children
Poststreptoccal GN (nephritic strains)
Known nephritic strains include M types 1, 2, 4, 12, 18, 25, 49, 55, 57, 60
Many proposed mechanisms: Molecular mimickry vs. autoimmune vs. polyclonal activation of B lymphocytes
Repeat infections are not common as immunity is type specific and not usually transient
Clinical Presentation Most patients have milder disease Classically, presents with overt nephritic
syndrome and oliguric ARF Symptoms can include gross hematuria
(100% microscopic), HA, htn (60-80%), hypervolemia, and edema (80-90%)
Clinical Presentation Nephritic urinary
sediment – dysmorphic RBCs, red cell casts, leukocytes, subnephrotic proteinuria
Nephrotic-range proteinuria not common
Labs
Serum Cr can be commonly elevated at presentation, though mild
C3 and CH50 decreased w/in 2 weeks C4 usually normal (complement level usually normal within 6-
8 weeks) Most patients have directed Ab, such as ASO, anti-DNAse B,
etc Serum IgG and IgM increased in 80% and returns to normal
in 1-2 months Polyclonal cryoglobulinemia in 75%
Light MicroscopyOn light microscopy,
usually see diffuse proliferative GN
Immunofluorescence Microscopy Deposition of IgG and
C3
3 patterns
mesangialStarry sky (mesangial
and capillary wall)Garland (capillary loops)
Electron Microscopy large electron – dense
immune deposits in subendothelial, subepithelial, and mesangial areas
Course Irreversible Renal Failure rare – less than 1 % in
children, slightly higher in adults Resolution usually quick, plasma Cr usually
returns to previous levels by 3-4 weeks Hematuria resolves usually within 3-6 months,
proteinuria falls at a slower rate Some patients experience htn, recurrent
proteinuria, and renal insufficiency 10-40 yrs after > 20% of adults may have some degree of
persistent proteinuria and or compromise of GFR 1 year out
Treatment Eliminate strep infxn with abx Supportive therapy Diuretics and antihypertensives to control
bp and extracellular fluid volume
Acute GN and Pulmonary Hemorrhage ANCA associated systemic vasculitis and anti-
GBM - common causes Also reported to occur in SLE, HSP, mixed
Cryoglobulinemia Study of 88 patients with Pulmonary Hemorrhage
and Nephritis: 48 ANCA, 6 Anti GBM, 7 both, 27 neither ANCA nor anti-GBM (latter group – not many causes could explain both findings)
The End
References Rose, Burton. “Acute Glomerulonephritis and Pulmonary
Hemorrhage, “Course of Poststreptococcal Glomerulonephritis. Up To Date 2005.
Harrison’s Online. Glomerular Disease. Ch 264. 2004-2005. Niles JL, et al. The Syndrome of Lung Hemorrhage and Nephritis
is Usually an ANCA – Associated Condition. Arch Intern Med. 1996; 156: 440-445.
Gallagher H, et al. Pulmonary Renal Syndrome: A 4 Year, Single-Center Experience. Am J of Kidney Disease 2002; 39: 42-47.
Berrrios X, et al. Post-streptococcal Acute Glomerulonephritis in Chile – 20 Years of Experience. Pediatr Nephrol 2004; 19: 306-312.
Johnson RJ, et al. Glomerular Disease Associated with Infection. Ch 30. Comprehensive Clinical Nephrology. 2000.