Rapidly deteriorating kidney function in a young man previously diagnosed with membranous nephropathy

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.

STUDY DESIGN

Case series.

SETTING & PARTICIPANTS

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

OUTCOMES

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.

LIMITATIONS

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.

Acute kidney injury in a patient with membranous nephropathy - a case report

Acute Kidney Injury (AKI) is one of the most challenging problems faced by clinicians in the tropics owing to its fast-changing burden. Acute Kidney Injury is an important complication of membranous nephropathy. Causes are varied and include hypovolumia, crescentic conversion of preexisting nephropathy, renal vein thrombosis, NSAID'S, vasculitis, and sepsis. In this case report we discuss the case of membranous nephropathy in a young adult complicated by AKI. This report highlights the importance of early renal biopsy in patients with post GE AKI not improving on hemodialysis. Here we also discuss the potential differentials to be considered in a case of membranous nephropathy with AKI.