Membranous nephropathy with crescents: a series of 19 cases.
BACKGROUND
Membranous nephropathy (MN) with crescents is rare and, in the absence of lupus, usually is associated with anti-glomerular basement membrane (anti-GBM) nephritis or antineutrophil cytoplasmic antibody (ANCA)-positive glomerulonephritis. Only rare cases of crescentic MN without ANCA or anti-GBM have been reported.


METHODS
Case series.


METHODS
19 patients with ANCA- and anti-GBM-negative crescentic MN and no clinical evidence of systemic lupus.


RESULTS
Clinical features, kidney biopsy findings, laboratory results, treatment, and follow-up of patients with crescentic MN.


RESULTS
Mean age was 55 (range, 5-86) years. All patients presented with proteinuria (mean protein excretion, 11.5 [range, 3.3-29] g/d) and nearly all had hematuria; 16 of 19 (84%) patients had decreased estimated glomerular filtration rates (eGFRs; mean serum creatinine, 2.9 [range, 0.4-10] mg/dL; mean eGFR, 39.7 [range, 4 to >100] mL/min/1.73 m2). Glomeruli showed on average 25% (range, 2%-73%) involvement by crescents. All showed a membranous pattern; 7 showed mesangial and 2 showed segmental endocapillary proliferation. By immunofluorescence, all cases showed granular subepithelial immunoglobulin G (IgG) and κ and λ light chains, and all but one showed C3; 5 showed C1q or IgA. Electron microscopy revealed stages I-III MN; 38% of cases were M-type phospholipase A2 receptor (PLA2R) associated, indicating that at least some were primary MN. Follow-up clinical data were available for all patients (mean, 22 [range, 1.5-138] months). 14 patients received immunosuppressive therapy, and 2, only angiotensin-converting enzyme inhibitor/angiotensin receptor blocker therapy. 4 patients (21%) progressed to end-stage renal disease, at 0-9 months postbiopsy. Mean serum creatinine level of those without end-stage renal disease at follow-up was 1.7 (range, 0.5-4.1) mg/dL; mean eGFR was 53.3 (range, 16-103) mL/min/1.73 m2. 67% of patients had proteinuria with protein excretion≥1 (mean, 3.2) g/d at follow-up.


CONCLUSIONS
Retrospective study.


CONCLUSIONS
Crescentic MN is a rare variant of MN that usually presents with heavy proteinuria, hematuria, and decline in GFR. The prognosis is variable and the disease may respond to therapy, but most patients develop a long-term decline in GFR.
Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN.
Erika F
EF
Rodriguez
Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN.
Samih H
SH
Nasr
Nephropathology Associates, Little Rock, AR.
Christopher P
CP
Larsen
Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN.
Sanjeev
S
Sethi
Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN.
Mary E
ME
Fidler
Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN. Electronic address: cornell.lynn@mayo.edu.
Lynn D
LD
Cornell
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000906:Antibodies / Q000097:blood; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000097:blood; D001706:Biopsy; D002648:Child; D002675:Child, Preschool; D005500:Follow-Up Studies; D050533:Glomerular Basement Membrane / Q000276:immunology; D005919:Glomerular Filtration Rate / Q000502:physiology; D015433:Glomerulonephritis, Membranous / Q000188:drug therapy* / Q000276:immunology / Q000473:pathology*; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use*; D007668:Kidney / Q000473:pathology* / Q000503:physiopathology; D008875:Middle Aged; D012189:Retrospective Studies; D016896:Treatment Outcome; D055815:Young Adult
D000906:Antibodies; D019268:Antibodies, Antineutrophil Cytoplasmic; D007166:Immunosuppressive Agents
Crescentic glomerulonephritis; case series; immune complex; kidney; membranous glomerulonephritis; membranous glomerulopathy; renal biopsy