Download - Glomerulonephritis in children
Glomerulonephritis in children
Pavlyshyn H.A.
Acute glomerulonephritis is the inflammation of the glomeruli which causes the kidneys to malfunction
• It is also called Acute Nephritis, Glomerulonephritis and Post-Streptococcal Glomerulonephritis
• Predominantly affects children from ages 2 to 12
• Incubation period is 2 to 3 weeks
Some progress as either focal segmental glomerulosclerosis ortubulointerstitial nephritis
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• Proteinuria – asymptomatic• Haematuria – asymptomatic• Hypertension• Nephrotic syndrome• Nephritic syndrome• Acute renal failure• Rapidly progressive renal failure• End stage renal failure
Presentation
• Hematuria with Proteinuriawith Dysmorphic rbcswith Rbc casts
• Oliguria
• Volume overload
• Hypertension
Liquid Renal Biopsy
Urine Sediment Analysis
G4 cell
Other H&P findings
• Neurological changes• Pharyngitis• URI / sinusitis• Hemoptysis• Rash• Murmur• Arthritis• Edema
Complement AbnormalitiesAb-Ag complexes
Classical pathway C3 convertase
Microbial surfaces(polysaccharides)
Alternative pathway C3 convertase
C3 C3b
C3a
(C4 + C2) (C4bC2a) Membrane attack complex
Recruitment of PMNs
Opsonization, phagocytosis
Anaphylaxis,Chemotaxis
Differential Diagnosis
Hypocomplementemia
• PIGN• MPGN• SLE• Cryoglobulinemia• Bacterial Endocarditis• Shunt nephritis
Normal complement
• HUS• IgAN• HSP• Alport’s / TBMD
-hemolytic Streptococci
• Most common organism in PIGN
• 20% children are asymptomatic carriers
• Nephritic factor
• Host susceptibility factors (HLA-DR)
• Treatment of prodromal illness doesn’t prevent nephritis
• ASO titers are NOT helpful
Post Infectious GN
Pathogenesis• Strep antigens trigger antibodies that cross-react to glomeruli • Circulating immune complexes get filtered by glomerulus & get
stuck• Immune complexes activate complement• Diffuse & generalized damage to glomeruli• ↓ GFR due to inflammation, damage to BM• ↓ RBF in proportion to GFR, so filtration fraction normal• Tubular function is preserved• Plasma renin and aldosterone are normal
Presentation• 7-14 days after pharyngitis• 14-21 days after impetigo (upto 6 wks)• Abrupt onset
Manifestations of PIGN
• Edema 85%• HTN 60-80%• Gross hematuria 25-33%• CNS (i.e. Sz) 10%• Nephrotic syndrome rare• ARF not uncommon• C3 decreased• C4 typically normal
Management of PIGN
• Antibiotics do NOT prevent GN• Sodium & Fluid restriction• Antihypertensives, diuretics for HTN• Dialysis if necessary• Prognosis usually excellent
0.5% mortality due to pulmonary edema or pneumonia<1% progress to CKD stage 5
• Follow-upGross hematuria resolves within 2 weeksComplement low for 6-8 weeksProteinuria remains upto 6 monthsHematuria remains upto 2 years
Renal Biopsy
Histopathology
Diffuse = all glomeruli
Generalized = all segments of glomeruli
IgG Immunofluorescence
Starry Sky Pattern
Electron microscopy - Normal
Foot processes
Basementmembrane
Electron microscopy of PIGN
• Subepithelial immune deposits (humps) Mesangial, subendothelial, intramembranous deposits less common
• Effacement of foot processes
Hemolytic Uremic Syndrome
• 2 cases/100,000 annually
• Peak incidence <5yo (6/100,000)
• More common June-September
• ClassificationD+ diarrhea associatedStrep pneumoAtypical HUS ADAM-TS13, C1q
def
Presentation of D+ HUS
• Prodromal acute gastroenteritis Shiga toxin producing E.coli O157:H7 Transmission from beef, veggies, direct person-to-person, and
contaminated water all reported Incubation period 3-4 days Bloody diarrhea 2-3 days after cramping begins 50% with emesis, afebrile or low grade fever only
• Hemolytic anemia• Thrombocytopenia• ARF
Begins 2-14 days after diarrhea
• CNS disease Overlap with ITP in 33% HUS cases Somnolence, confusion, seizures, coma
Microangiopathic Hemolytic Anemia
Henoch Schönlein Purupura
Henoch Schönlein Purupura
• GI tractCramping, vomiting, diarrhea
• Skin rashLower extremities, buttocks
• Joint involvement• HSP nephritis
Incidence 20-50%In 80%, occurs within 4 weeks of rash & GI upsetIn 15%, occurs upto 1-3 months after rash & GI
upset
Pathogenesis of Alport’s
• Abnormality of type IV collagen
• Disordered basement membrane
• Splitting of lamina densa of GBM
Crescentic GN
Type Serology Primary Secondary
I Anti-GBM+ ANCA- Anti-GBM disease Goodpasture’s
II Anti-GBM- ANCA- idiopathic SLE, IgAN, MPGN
III Anti-GBM- ANCA+ Microscopic polyangiitis,
Wegener’s
Drug-induced
IV Anti-GBM+ ANCA+ Anti-GBM disease Goodpasture’s
Vasculitides
C-ANCA P-ANCAAnti-proteinase 3 antibodies Anti-myeloperoxidase antibodies
75% sensitive for Wegener’s 66% sensitive for Microscopic polyangiitis
Anti-GBM Disease
Silver stain IgG immunofluorescence