[1694] Interstitial Eosinophilic Aggregates Is Distinctly More Common in Diabetic Nephropathy Than Other Glomerulopathies

Kotaro Sasaki, Kelly Smith, Roberto Nicosia, Charles E Alpers, Behzad Najafian. University of Washington Medical Center, Seattle

Background: The presence of interstitial eosinophilic aggregates (IEA) in renal biopsies is commonly interpreted as allergic type tubulointerstitial nephritis (TIN-A). However, in many cases, no significant correlation with a history of drug-use can be found. Here, we studied the prevalence of IEA in diabetic nephropathy (DN) as well as other common types of glomerulopathy.
Design: Diagnostic reports made by one pathologist between January 2010 and August 2011 were reviewed. The cases with DN (n=74) or other glomerulopathies including IgA nephropathy (IgAN) (n=43), membranous nephropathy (MN) (N=40), thrombotic microangiopathy (TMA) (n=14), amyloidosis (n=15), focal segmental glomerulosclerosis (FSGS) (n=121), membranoproliferative glomerulonephritis (MPGN) (n=10) were analyzed for the presence of IEA. A frequency of concurrent diagnosis among cases diagnosed as TIN-A (n=26) was also analyzed. Finally, demographics (age, sex, type1 vs type2 diabetes), and a history of antibiotics/NSAIDS use obtained from pathology requisition forms, and reported pathologic severity of mesangial expansion (advanced vs mild) were compared between cases of DN with (DN-IEA) and without (DN-nonIEA) concurrent IEA.
Results: Cases with DN have significantly higher frequency of concurrent IEA (27/74, 36%) compared with other glomerulopathies including IgAN (4/43, 9.3%, P<0.01), MN (5/40, 13%, P<0.01), TMA (0/14, 0%, P<0.01), amyloidosis (1/15, 0%, P<0.01), FSGS (19/121, 16%, P<0.001), and MPGN (0/10, 10%, P=0.02). Among cases with TIN-A, DN is the leading concurrent condition (13/26, 50%), followed by acute tubular injury (7/26, 27%), FSGS (4/26, 15%), other nonspecific chronic changes (3/26, 12%), IgAN (1/26, 3.8%), and MN (1/26, 3.8%). No significant difference was observed between DN-IEA and DN-nonIEA in age (55 yr vs 57 yr), sex, frequency of type I diabetes (8.3% vs 26.3%), antibiotic use (9.5% vs 16%), or NSAIDS use (30% vs 22%). DN-IEA shows significantly higher frequency of advanced mesangial expansion compared with DN-nonIEA (84% vs 60%, P=0.03).
Conclusions: IEA is a common concurrent finding in renal biopsies with DN. Correlations with the severity of glomerular changes suggest the probable link to the pathophysiology and natural history of DN. Correlations with other pathologic and clinical parameters are currently under further investigations.
Category: Kidney (does not include tumors)

Wednesday, March 21, 2012 1:00 PM

Poster Session VI # 305, Wednesday Afternoon


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