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Nephritic vs. nephrotic?

- nephritic:
+ RBCs, - WBCs
red cell or mixed cellular casts
variable degrees of proteinuria

- nephrotic:
proteinuria greater tahn 3.5 g/day (sig amount)
lipiduria, fatty casts


What are nephritic causes of glomerulonephritis?

- postinfectious glomerulonephritis
- IgA nephropathy
- HSP aka IgA vasculitis
- mesangial proliferative glomerulonephritis
- lupus nephritis
- thin basement membrane disease
- hereditary nephritis
- membranoproliferative glomerulonephritis
- rapidly progressive (crescentic) glomerulonephritis


nephrotic causes of glomerulonephritis?

- systemic: diabetic nephropathy, amyloidosis, systemic lupus
- minimal change disease (kids)
- FSGS (focal segmental glomerulosclerosis)
- membranous nephropathy


Focal nephritic disease characteristics?

- inflammatory lesions in less than 1/2 glomeruli
- UA shows RBCs, occasional RBC casts, mild proteinuria
- example: IgA nephropathy


Diffuse nephritic disease characteristics?

- affects more than 1/2 of the glomeruli
- UA similar to focal but will have more proteinuria, also edema, HTN and/or renal insufficiency
- ex: PSGN


Patterns of nephrotic disease?

- affects MANY of the glomeruli
- w/o obvious inflammation or immune complex deposition
- edema, hyperlipidemia, hypoalbuminemia
- ex: diabetic nephropathy


Epidemiology of PSGN?

- most common cause of acute nephritis worldwide
- it primarily occurs in developing world
- risk is greater in kids b/t 5-12 years of age
- annual incidence: 20/100000


When does PSGN present itself?

- usually occurs 1-3 weeks post strep throat
- 3-6 weeks post skin infection with GABS
- abx doesn't always prevent glomerular disease


Pathophys of PSGN?

- caused by glomerular immune complex disease induced by specific nephritogenic strains of GABS
- can also be assoc with various viral illnesses and parasitic infections (rare)
- resulting glom. immune complex disease triggers complement activation and inflammation


Clinical signs and sxs of PSGN?

- often asx
- microscopic hematuria - lead to gross hematuria
- proteiniuria (can reach nephrotic range)
- edema
- increased serum creatinine
- variable decline in GFR
- hypocomplementemia (C3, C4)
- acute renal failure and need for dialysis is uncommon


Dx tests for PSGN? Signs that rule out PSGN?

- look for elevated titers of Abs to extracellular strep (evidence of recent GABS)
- streptozyme test measure 5 strep abs, 95% positive in pharyngitis and 80% positive in skin infections
- Most common ab: ASO (anti-streptolysin)

- renal bx: NOT performed in most pts to confirm dx of PSGN but it can be performed if:
other glomerular disorders are being considered because they deviate from the natural course of PSGN
-or it presents late w/o clear hx of prior strep infection

- Persistently low C3 levels beyond 6 weeks are suggestive of a dx membranoproliferative glomerulonephritis
- recurrent episodes of hematuria: ****suggest IgA nephropathy, rare in PSGN


Tx of PSGN?

- management is supportive and focused upon tx the volume overload and HTN
- Na and water restriction
- Diuretic: lasix tx HTN and volume overload
- Dialysis may be reqd in acute renal failure


Prognosis of PSGN?

- most pts, esp kids, have complete recovery, and resolution of their disease process - within the first 2 weeks
- small subset: have late renal complications (HTN, increasing proteinuria, and renal insufficiency)


Epidemiology of IgA nephropathy (Berger's disease)?

- most common lesion to cuase primary GN in developed world
- higher frequency in Asians and caucasians (rare in blacks)
- Male to female 2:1
- age: 80% b/t 15-35 yo at dx


Pathophys of Berger's disease?

- unknown
- initiating event: mesangial deposition of IgA
- dysregulated synthesis and metabolism of IgA results in immune complexes that lead to mesangial depositon and accumulation
- enviro factors: dietary Ags and mucosal infections may drive the generation of pathogenic IgA


Presentation of Berger's disease?

can present in 1 of 3 ways:
- 50% present with gross hematuria (may be recurrent, usually after URI), flank pain, fever
- 30% present with microscopic hematuria (eventually will lead to gross hematuria), mild proteinuria
- 10% present with: nephrotic syndrome (proteinuria, lipiduria, fatty casts), edema, renal insufficiency, HTN: rare malignant HTN, hematuria


Dx of Berger's disease?

- suspicion based on clinical hx and UA
- confirmation: prominent IgA deposits in mesangium and along glomerular capillary walls, C3 and IgG are also deposited
- Mesangial IgA deposition also occurs in cirrhosis, celiac disease, and HIV
- IgA nephropathy may rarely be seen with other glomerular diseases - minimal change disease and granulomatosis with polyangiitis (wegeners)


Tx of IgA nephropathy?

- BP control
- ACEIs/ARBs: pts with persistent proteinuria, slightly reduced GFR, and mild/mod changes in bx
- look for reduction in protein excretion
- pt with severe or progressive disease: corticosteroids and/or immunosuppressants


IgA nephropathy (bergers) prognosis?

- most pts enter sustained clinical remission
- some have persisten low-grade hematuria and or proteinuria
- slow progression to ESRD occurs in 50%
- predictors of progression: elevated serum Cr, HTN, and persistent protein excretion above 1000 mg/day
- patients who have recurrent episodes of gross hematuria w/o proteinuria are at low risk for progressive kidney disease


What is HSP/IgA vasculitis? Who does it usually effect?

- systemic vasculitis characterized by tissue deposition of IgA containing immune complexes
- most common cause of vasculitis in children (90%)
- HSP: usually occurs b/t 3-15
- underlying cuase of HSP unknown main theory: immune mediated vasculitis, may be triggered by variety of Ags


What is the tetrad of clinical manifestations of HSP?

- palpable purpura w/o thrombocytopenia or coagulopathy
- arthritis/arthralgias
- abdominal pain
- renal disease (GN)

- this can develop over days to weeks and manifestations can vary in order of presentation


Pathogenesis of HSP nephritis?

- similar to IgA nephropathy ( deposition of IgA immune complexes)
- can have mild (asx hematuria) to varying degrees of proteinuria to severe presentation with nephrotic syndrome and even renal failure
- generally mild in children, moderate to severe in adults


Dx of HSP nephritis?

- confirmed by kidney bx
- reserved for when dx is uncertain or severe renal involvement: marked proteinuria and or impaired renal fxn during the acute episode


Prognosis of HSP nephritis? Tx?

- Renal disease is favorable in most, recurrence is common
- minority will develop persistent renal manifestations or ESRD

- pts with cresentic GN: pulse IV methylprednisolone, followed by oral prednisone
- dialysis and renal transplantation cna be performed for those that progress to ESRD


What is RPGN (rapidly progressive GN)? Characterized by?

- acute GN marked by rapid progression to ESRF
- features of glomerular disease in urine
- progressive loss of renal fxn over short period (days, weeks, months)
- characterized morphologically by extensive CRESCENT formation and clinically progression to ESRD


Pathophys of RPGN?

- crescentic GN: crescent formation nonspecific response to severe injury to glomerular cap wall
- initially begins as active inflammation of cap wall, results in movement of plasma products, including fibrinogen, into Bowman's space with subsequent fibrin formation, the influx of macrophages and T cells, and the release of proinflamm cytokines
- followed by the development of fibrocellular and fibrous crescents, which represent a stage of disease that isn't likely to respond to immunosuppressive therapy


Types of RPGN?

- anti-glomerular basement membrane (GBM/goodpastures): Ab disease of LUNGS and glomerulus caused by anti-GBM ABs
- Immune complex RPGN: deposition of immune complexes in the glomeruli: IgA nephropathy, PSGN, lupus nephritis
- Pauci-immune RPGN: necrotizing GN and vasculitis: ANCA positive, systemic sxs of vasculitis


Presentation of RPGN? What if it is GBM?

- insidious onset: fatigue and edema
- more acute onset: macroscopic hematuria, oliguria, edema, renal insufficiency

- If GBM:
pulmonary hemorrhage, hemoptysis, pulmonary infiltrates, dyspnea


RPGN eval?

- UA: hematuria, RBC casts and other casts, proteinuria
- high BUN, and creatinine
- Renal bx
- serologic assays to determin type and cause:
ANCA, anti-GBM abs, ANAs


Tx of RPGN?

- early dx with renal bx and serologic testing and early tx is essential to min. degree of irreversible renal injury
- empiric therapy with severe disease while awaiting bx results:
pulse methylprednisolone
oral or IV cyclophosphamide
sometimes: plasmapharesis
- tx after bx results: specific