A Case of Membranous Glomerulonephritis with Superimposed Anti-Neutrophil Cytoplasmic Antibody-Associated Rapidly Progressive Crescentic Glomerulonephritis

Crescentic Glomerulonephritis and Membranous Nephropathy: A Rare Overlap

Background

Membranous nephropathy (MN) is a disease that affects the basement membrane of the glomeruli of the kidney resulting in proteinuria. The concurrent incidence of vasculitic glomerulonephritis and MN in the same patient is unusual. Herein, we report a case with this unusual combination.

Case

Our patient is a 53-year-old Hispanic male with a medical history of tobacco use, type 2 diabetes mellitus, and hypertension who presented with hematuria and was found to have nephrotic range proteinuria and renal impairment. Blood workup revealed positive ANCA serology, which led to a renal biopsy that showed crescentic vasculitis in addition to membranous nephropathy. The patient was started on intermittent hemodialysis (HD) and treated initially with intravenous (IV) pulse steroids; subsequently, oral prednisolone and IV cyclophosphamide were initiated. The patient remained HD dependent at the time of discharge with the resolution of hematuria. A follow-up with an outpatient nephrology clinic was arranged.

Conclusion

Membranous nephropathy complicated by crescentic glomerulonephritis has a more aggressive clinical course and decline in renal function compared to MN alone which can lead to initiating renal replacement therapy. However, immunosuppressive drugs can result in significant improvement of renal function if started early enough.

Clinicopathologic characteristics and outcomes of lupus nephritis with positive antineutrophil cytoplasmic antibody

Aims: The aim was to determine whether anti-neutrophil cytoplasmic antibody (ANCA)-positive serology in patients with lupus nephritis (LN) is associated with different clinicopathologic features and outcomes.Methods: In our retrospective analysis, 283 patients were enrolled between 2013 and 2018. Thirty-six patients were ANCA-positive, and this group was compared with the remaining 247 patients who were confirmed as ANCA-negative at the time of biopsy.Results: ANCA-positive LN patients exhibited higher anti-dsDNA antibody titers and serum creatinine levels and lower serum hemoglobin concentrations than ANCA-negative LN patients. On pathological evaluation, segmental endocapillary hypercellularity observed by light microscopy was significantly more common in the ANCA-positive group. This feature was not significantly different in the treatment group, but the response to treatment was significantly different, as was remission (76.1% vs 69.4%, p < 0.001), between the ANCA-negative and ANCA-positive groups. During follow-up, the times to renal replacement therapy (RRT) and death were significantly different between the two unmatched groups (chi-square test, p = 0.041). Multivariate Cox analysis revealed that neurological disorders, ANCA positivity, and the chronicity index (CI) remained independent risk factors for patient survival. Pulmonary infection was the main cause of death and was most often due to fungal infection.Conclusion: ANCA-positive LN patients typically exhibited higher anti-dsDNA antibody titers, lower serum hemoglobin concentrations and worse renal function than ANCA-negative LN patients. Fungal infection was the main cause of death. We observed that ANCA positivity was an independent risk factor for patient survival.