Glomerulonephritis Flashcards
Nepritic syndromes characteristics/signs
- classic presentation of pts w/glomerulonephritis
- reduction of GFR ==> elevated serum creatinine
- hematuria + dysmorphic RBCs and/or RBC casts + proteinuria
- WBCs also possible
- hypertension + edema
Typical renal-limited diseases associated w/glomerulonephritis
- IgA nephropathy
- Anti-GBM disease
- Membranoproliferative glomerulonephritis (MPGN)
- Renal limited vasculitis (ANCA associated)
- Hemolytic-uremic syndrome
- C3 glomerulopathy/Dense deposit disease
Typical systemic diseases associated w/glomerulonephritis
- Henoch-Schönlein Purpura
- Goodpasture’s syndrome
- Lupus nephritis
- ANCA associated vasculitis
- Infection associated
- Post-infectious
- Endocarditis/shunt nephritis
- Cryoglobulinemia
- Immunoglobulin deposition diseases
Common labs/serology evaluation in glomerulonephritis
- lab: CBC, electrolyte, 24-hour urine, liver fxn tests
- serology:
- C3 (complement) levels
- antistreptolysin (ASO) titer
- ANA, ANCA, cryoglobulins, anti-GBM
Pulmonary-renal syndrome definition
- patients presenting w/glomerulonephritis + pulmonary hemorrhage
- e.g. in Goodpasture’s or ANCA-associated vasculitis
Blood tests + disease associations in glomerulonephritis
ANA, Anti-DS DNA
Lupus
C3, C4
See table
Blood cultures
Bacterial endocarditis
ASO
Post-infectious
Hepatitis C
Cryoglobulinemia
Hepatitis B
Membranoproliferative glomerulonephritis
Anti-neutrophil cytoplasmic antibodies (ANCA)
Pauci-immune vasculitis
Anti-GBM antibodies
Anti-GBM disease, Goodpasture’s syndrome
Pathophysiology of proteinuria in glomerulonephritis
- direct damage to glomerular capillary wall via immunologic mechanisms ==> increased protein filtration
Pathophysiology of reduction of GFR in glomerulonephritis
- reduced GFR <== acute, inflammatory process w/in glomerulus
- ==> glomerular vasocontsriction/occlusion or thrombosis ==> decreased filtration surface area
Pathophysiology of active urine sediment in glomerulonephritis
- excretion of RBCs, WBCs, or casts <== glomerular inflammation + disruption of GBM
Pathophysiology of edema/hypertension in glomerulonephritis
- edema <== increase in tubular reabsorption of salt + water <== reduced glomerular perfusion w/normal tubular fxn ==> expansion of ECF volume
- HTN <== salt + water retention
Epidemiology/etiology: Post-infectious glomerulonephritis
- occurs 2-3 wks after Group A strep infection
- most common in children
- may occur w/acute or subacute active infections
- mediated by Ab response to strep ==> immune complex deposition + activation of complent @ glomeruli
Pathology/Clinical Presentation: Post-infectious glomerulonephritis
- light microscope: proliferative + exudative w/inflitration of PMNs and monocytes
- Immunofluorescence: IgG + C3 deposits @ subendothelial, mesangial, subepithelial
- clinical present:
- edema + sudden weight gain + HTN
- hematuria + proteinuria
- decreased GFR
- Positive ASO titer
- decreased C3 w/normal C4
Diagnosis/Tx: Post-infectious glomerulonephritis
- Dx: nephritic syndrome + positive streptozyme + low C3
- Tx: supportive
Epidemiology/etiology: IgA Nephropathy
- most common; usually males 15-35
- mediated by deposition of IgA complexes @ mesangium ==> activation of mesangial cells ==> cell proliferation
Pathology/Clinical: IgA Nephropathy
- light: increase in mesangial cell number/matrix
- IF: IgA, IgG, C3 @ mesangium
- Clinical:
- usually asymptomatic
- often increased hematuria w/onset of viral illness
- systemic sx possible
- skin w/IgA deposits = Henoch-Schonlein purpura
Epidemiology/etiology: MPGN
- MPGN = mesangial proliferation + thickeneing of GBM
- epidemiology = associated w/systemic illness or idiopathic<== adolescents + female > male
Pathology/Pathogenesis: MPGN
- LM: thick basement membrane, mesangial cell proliferation + lobulated appearance
- Deposits @ capillary walls, mesangium: C3, IgG
- EM: subendothelial + mesangial deposits
- Pathogenesis: trapping of circulating immune complexes
Clinical Presentation: MPGN
- acute glomerulonephritis or nephritic syndrome
- early HTN
- common test results: Hep C infection w/HCV and RNA in blood + cryoglobulins
- RF
- low complement (C3 & C4)
Tx/Prognosis: MPGN
- poor prognosis ==> end-stage renal disease
- sometimes steroids
- Hep C + ==> anti-viral
Pathology: Anti-GBM disease
- Ab binds to type IV collagen w/in GBM ==> linear IgG deposits ==> glomerulonephritis
- Abs ==> complement activation + PMN infiltration
- crescent formation + rapid loss of renal fxn
Clinical Presentation/Tx/Prognosis: Anti-GBM disease
- pulmonary hemorrhage + iron deficiency anemia + nephritis
- Tx: steroids + immunosuppresion + plasma exchange ==> increases renal survival
Pathology/Pathogenesis: Pauci-Immune Renal Vasculitis
- PIRV=small vessel vasculitis involving the kidney but w/out immune-complex deposition
- Path: fibrinoid necrosis + crescents
- Pathogen:
- ANCA (anti-neutrophil cytoplasmic Ab) positive
Clinical Presentation/Tx: Pauci-Immune Renal Vasculitis
- Can present @ skin, lungs, GI (and renal)
- w/lungs = pulmonary-renal syndrome
- nephritic pattern of renal disease
- Tx: immunosuppresive drugs; steroids + cyclophosphamide or rituximab
- possible: plasma exchange; dialysis
Pathology/Pathogenesis: Lupus Nephritis
- Path: immune-complexes @ mesangium, subepithelium, subendothelium w/lumpy-bumpy pattern
- Pathogen: autoantibody disease e.g. ANA (Anti-nuclear antibody)
Clinical Presentation/Tx: : Lupus Nephritis
- Renal signs: heamturia, proteinuria
- either nephritic or nephrotic
- Tx: steroids + cyclophosphamide
Clinical Presentation/Tx: Cryoglobulinemia
- Systemic sx: palpable purpura, arthralgias, generalized weakness
- Urine: Proteinuria, hematuria
- Labs: low C4, cryoglobulins, RF
- Tx: antiviral (w/Hep C)
- rituximab if lymphoproliferative disease
- plasmapheresis
Pathology/Pathogenesis: Cryoglobulinemia
- Path: immune-complex glmerulonephritis
- memranoproliferative pattern of injury + subendothelial immune deposition
- Pathogen: Cryoglobulins = frequently associated w/Hep C infection
- cooling blood ==> immune complex formation
Characteristics of Henoch-Schonlein purpura (HSP)
- clinical:
- skin lesions (palpable purpura)
- arthritis
- GI involvement
- glomerulonephritis
- path:
- focal proliferative necrotizing glomerulonephritis w/crescent formation
- mesangial + cap wall deposits of IgA
