Membranous Glomerulonephritis with Crescents.
Erika F Rodriguez, Samih H Nasr, Sanjeev Sethi, Mary E Fidler, Lynn D Cornell. Mayo Clinic, Rochester, MN
Background: Only rare cases of membranous glomerulonephritis (MGN) with crescents have been reported. We present a series of ANCA-negative MGN with crescents.
Design: We searched the pathology database at our institution from 1/1994-9/2010 for cases of MGN with crescents from non-lupus patients who had negative ANCA and anti-GBM antibodies. We examined in detail the clinicopathologic features and outcomes in these patients.
Results: A total of 4215 cases of MGN, both primary and secondary, were identified. Of these, 12 patients (0.3%) had ANCA- and anti-GBM-negative crescentic MGN. The mean age at diagnosis was 47 yrs (range 5-86); half were female. At presentation, all patients had proteinuria (mean 11.3 g/d; range 3.3-26) and hematuria, and 10/12 (83%) patients had renal failure (mean serum Cr 3.3 mg/dL; range 0.4-10). ANA was negative in 9 patients and transiently or weakly positive in 3 patients; no patients had hepatitis B or C infection. On light microscopy, glomeruli showed on average 26% involvement by crescents (range 5-73%), with 10/12 cases showing <50% crescents. All cases showed a membranous pattern; 6 cases showed mild mesangial and 2 showed segmental endocapillary proliferation. By immunofluorescence, all cases with glomeruli (n=11) showed a membranous pattern with staining for IgG, kappa, and lambda, and all but one showed C3; 2 cases showed staining for C1q (trace and 2+) and one showed trace IgA. By electron microscopy, most cases showed stage II MGN. 2 showed mesangial deposits, and one showed subendothelial deposits. Endothelial tubuloreticular inclusions were seen in one case. Follow-up clinical data were available in all 12 cases (mean 32 mos; range 0.5-138). 10 patients were treated, 5 with high-dose prednisone and cyclophosphamide, 2 with steroids and a calcineurin inhibitor (tacrolimus or cyclosporine), 2 with prednisone alone, and one with enalapril alone. 2 patients progressed to ESRD, at 0-2 mos post-biopsy. The mean serum Cr of the other 10 patients at follow-up was 1.6 mg/dL (range 0.5-4.1), with 8/10 (80%) patients showing elevated serum Cr. 6 of 7 patients with available data and without ESRD had ≥1 g/d proteinuria at follow-up. One patient later had an equivocal MPO titer, and another had a positive MPO titer 8 mos after biopsy. No patients developed lupus. 2 patients had follow-up biopsies, at 1.3 and 4.6 years later: one had MGN without crescents, and the other had MGN with focal crescents.
Conclusions: Crescentic MGN is a rare variant of MGN that usually presents with heavy proteinuria, hematuria, and renal failure. The prognosis is variable and the disease may respond to therapy, but most patients develop chronic renal failure.
Category: Kidney (does not include tumors)
Wednesday, March 2, 2011 1:00 PM
Poster Session VI # 240, Wednesday Afternoon