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Old 05-25-2012
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Question Guess which autoimmune antibody here?

A 61-year-old man visits his primary care physician for a 1-month follow-up evaluation of a flu-like syndrome that had persisted for 3 weeks. His symptoms during this episode included malaise, fever, and joint and muscle pain. He also had a poor appetite and experienced an 8 pound loss. Past medical history is significant for coronary vascular disease SP CABG x3 5 years ago. Today the man reports feeling much better over the last 2 weeks and has no specific complaints. Vital signs are temperature: 37.1C (98.7F), blood pressure: 170/100 mm Hg, heart rate: 70 beats/min, and respiratory rate: 14 breaths/min. Physical exam is within expected limits. Chest X-ray is without any evidence of infiltrates or granulomatous disease. Notable laboratory values are a serum blood urea nitrogen (BUN) 30 mg/dL and creatine 4.0 mg/dL compared with serum BUN 20 mg/dL and creatine 1.3 from blood samples drawn 1 month ago. A renal biopsy is ordered and subsequently shows diffuse proliferative fibrinoid necrosis with crescent formations present in 70% of glomeruli. Immunofluorescent staining shows no sign of immune complex deposition.


A. Antidouble-stranded DNA (anti-dsDNA) antibodies
B. Antiribosomal P protein antibodies
C. Antitopoisomerase-1 antibodies
D. Anti-Jo-1 antibodies
E. Anticentromere antibodies
F. Anti-U1 ribonucleoprotein (RNP) antibodies
G. Anti SS-A (Ro) antibodies
H. Cytoplasmic antineutrophil cytoplasmic antibodies (cANCAs)
I. Perinuclear antineutrophil cytoplasmic antibodies (pANCAs)
J. Anticardiolipin antibodies
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Old 05-25-2012
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B. Antiribosomal P protein antibodies
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Old 05-25-2012
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looks like polyarteritis nodosa (PAN).... the renal manifestation is definitely type 3 rapidly progressive GN i.e the pauci immune type, thats y IF didn't show anythn.... it is ANCA associated.... it could be either wegener's granulomatosis or PAN or microscopic polyangiitis.... the reason i am going with PAN is because his lungs are clear... PAN is the only autoimmune disease which doesnt affect the lungs... wegener's usually starts as sinusitis, then lung disease and kidney disease.. so the clinical picture is not in favour of wegener's granulomatosis... even microscopic polyangiitis can have lung problems but not necessarily... and PAN explains everything including his myocardial infarction.... and the elevation in BUN n creatinine.. the ratio is less than 15 in both sets of values given.. so its definitely renal azotemia, worsening over time, without any history of dehydration (which may suggest ischemic ATN as a shift from pre renal azotemia to renal azotemia, which isnt the case here), this is typical of PAN... so my answer is option I- pANCA.... though ANCA antibodies are rare in PAN... 2nd on list would be microscopic polyangiitis but even with that pANCA would be most likely answer...
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Old 05-25-2012
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Quote:
Originally Posted by neelmed View Post
looks like polyarteritis nodosa (PAN).... the renal manifestation is definitely type 3 rapidly progressive GN i.e the pauci immune type, thats y IF didn't show anythn.... it is ANCA associated.... it could be either wegener's granulomatosis or PAN or microscopic polyangiitis.... the reason i am going with PAN is because his lungs are clear... PAN is the only autoimmune disease which doesnt affect the lungs... wegener's usually starts as sinusitis, then lung disease and kidney disease.. so the clinical picture is not in favour of wegener's granulomatosis... even microscopic polyangiitis can have lung problems but not necessarily... and PAN explains everything including his myocardial infarction.... and the elevation in BUN n creatinine.. the ratio is less than 15 in both sets of values given.. so its definitely renal azotemia, worsening over time, without any history of dehydration (which may suggest ischemic ATN as a shift from pre renal azotemia to renal azotemia, which isnt the case here), this is typical of PAN... so my answer is option I- pANCA.... though ANCA antibodies are rare in PAN... 2nd on list would be microscopic polyangiitis but even with that pANCA would be most likely answer...
wow. excellent expl. ur expln is better than the qbank i took question from.

can u please elaborate on types of RPGN ... u were mentioning about pauci immune type ?? i know anything above type 2 is pauci immune... type 1 is Goodpasture and type 2 is ??
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Old 05-25-2012
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sure mate.... see we have 3 types of crescentic GN or what we call rapidly progressive GN... its very easy to differentiate between them... type 1 is where you see linear IF, that means anti GBM antibodies i.e Goodpasteurs syndrome.... type 2 is characterised by lumpy bumpy IF, which means immune complex deposition like in post streptococcal GN or SLE or IgA nephropahty.. then there is type 3 where IF doesn't reveal anything- no antibodies and no complement.... this is caused by ANCA associated vasculitides like PAN, Wegener's granulomatosis and microscopic polyangiitis..... so wen u see crescentic GN, js get the IF study and u will narrow down the differentials remarkably
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Quote:
Originally Posted by neelmed View Post
looks like polyarteritis nodosa (PAN).... the renal manifestation is definitely type 3 rapidly progressive GN i.e the pauci immune type, thats y IF didn't show anythn.... it is ANCA associated.... it could be either wegener's granulomatosis or PAN or microscopic polyangiitis.... the reason i am going with PAN is because his lungs are clear... PAN is the only autoimmune disease which doesnt affect the lungs... wegener's usually starts as sinusitis, then lung disease and kidney disease.. so the clinical picture is not in favour of wegener's granulomatosis... even microscopic polyangiitis can have lung problems but not necessarily... and PAN explains everything including his myocardial infarction.... and the elevation in BUN n creatinine.. the ratio is less than 15 in both sets of values given.. so its definitely renal azotemia, worsening over time, without any history of dehydration (which may suggest ischemic ATN as a shift from pre renal azotemia to renal azotemia, which isnt the case here), this is typical of PAN... so my answer is option I- pANCA.... though ANCA antibodies are rare in PAN... 2nd on list would be microscopic polyangiitis but even with that pANCA would be most likely answer...
The ratio of 15 a month ago is normal but now it is 7.5 which suggests intrinsic renal pathology.

My answer is pANCA (hypertension + renal failure + constitutional symptoms = vasculitis fibrinoid necrosis PAN variant microscopic polyangitis )
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http://medicine.med.nyu.edu/nephrolo...ulomatosis.pdf
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Old 05-26-2012
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ans is PANCA
qbank says patient has microscopic polyangitis
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Old 08-05-2012
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Quote:
Originally Posted by neelmed View Post
sure mate.... see we have 3 types of crescentic GN or what we call rapidly progressive GN... its very easy to differentiate between them... type 1 is where you see linear IF, that means anti GBM antibodies i.e Goodpasteurs syndrome.... type 2 is characterised by lumpy bumpy IF, which means immune complex deposition like in post streptococcal GN or SLE or IgA nephropahty.. then there is type 3 where IF doesn't reveal anything- no antibodies and no complement.... this is caused by ANCA associated vasculitides like PAN, Wegener's granulomatosis and microscopic polyangiitis..... so wen u see crescentic GN, js get the IF study and u will narrow down the differentials remarkably
That was great explanation, but I have something I want to spot some light on, if u don't mind.
Are you sure that post streptococcal GN is RPGN(crescent) type?

Kind regards
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Rapidly progressive glomerulonephritis (RPGN) is defined as any glomerular disease characterized by extensive crescents (usually >50%) as the principal histologic finding and by a rapid loss of renal function (usually a 50% decline in the glomerular filtration rate [GFR] within 3 mo) as the clinical correlate.

Quote:
Rapidly progressive glomerulonephritis (RPGN) is a disease of the kidney characterized clinically by a rapid decrease in the glomerular filtration rate (GFR) of at least 50% over a short period, from a few days to 3 months. The main pathologic finding is extensive glomerular crescent formation. The ubiquitous pathological feature of crescentic glomerulonephritis is a focal rupture of glomerular capillary walls that can be seen by light microscopy and electron microscopy.
The term rapidly progressive glomerulonephritis was first used to describe a group of patients who had an unusually fulminant poststreptococcal glomerulonephritis and a poor clinical outcome. Several years later, the antiglomerular basement membrane (anti-GBM) antibody was discovered to produce a crescentic glomerulonephritis in sheep, and, following this discovery, the role of anti-GBM antibody in Goodpasture syndrome was elucidated. Soon afterward, the role of the anti-GBM antibody in rapidly progressive glomerulonephritis associated with Goodpasture disease was established.
crescentic glomerulonephritis algorithym

Last edited by Novobiocin; 08-05-2012 at 03:53 PM.
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Originally Posted by Novobiocin View Post
Rapidly progressive glomerulonephritis (RPGN) is defined as any glomerular disease characterized by extensive crescents (usually >50%) as the principal histologic finding and by a rapid loss of renal function (usually a 50% decline in the glomerular filtration rate [GFR] within 3 mo) as the clinical correlate.



crescentic glomerulonephritis algorithym
Amazing.. I gotcha.. So it could be progression of any type of GN. Thanks alot Novobiocin.
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PATHOGENESIS OF CRESCENT FORMATION
Crescent formation appears to represent a nonspecific response to severe injury to the glomerular capillary wall [4]. Rents are induced in the glomerular capillary wall, resulting in the 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 proinflammatory cytokines, such as interleukin-1 and tumor necrosis factor-alpha [5,6]. Thus, crescents may be seen with any form of severe glomerular disease, including lupus nephritis and postinfectious glomerulonephritis, disorders that can usually be diagnosed from the history and typical immunofluorescence and electron microscopic findings. (See "Mechanisms of glomerular crescent formation".)
The stage of active inflammation is often followed by the development of fibrocellular and fibrous crescents [5]. Collagen deposition is due to fibroblast proliferation that is driven by fibroblast growth factors. Transforming growth factor-beta is also thought to play an important role. This transition is important clinically because fibrous crescents represent a stage of the disease that is not likely to respond to immunosuppressive therapy.
TYPES OF CRESCENTIC GN
The term RPGN refers to crescentic glomerulonephritis that is usually due to one of four disorders, which reflect different mechanisms of glomerular injury
  • Type I with linear deposits of immunoglobulin G (IgG) (anti–glomerular basement membrane [GBM] disease)
  • Type II with granular deposits of immunoglobulin (immune-complex mediated)
  • Type III with few or no immune deposits (pauci-immune) - Antineutrophil cytoplasmic antibody (ANCA)–associated (Renal-limited forms of ANCA-associated crescentic glomerulonephritis are thought to be related to small vessel vasculitis [SVV] with exclusive involvement of the glomerular capillaries.)
  • Type IV combinations of types I and III
  • Type V ANCA-negative renal vasculitis (5-10%)
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