Membranous Nephropathy With ANCA-Associated Necrotizing And Crescentic Glomerulonephritis:a Case Report And Literature ReVIEW

Objective:Superposition membranous nephropathy (MN) and anti-neutrophil cytoplasmic antibodies (ANCA)-associated necrotizing and crescentic glomerulonephritis (NCGN) is a rare condition. To better understand it, we report a case and performed a literature review.Methods:We describe a case with concurrent MN and ANCA-associated NCGN. A literature review was performed to examine the clinical and pathological features, treatment, and clinical follow-up of this condition.Results:We report a 58-year-old female with microscopic hematuria, proteinuria, and mild renal insufficiency. Light microscopy analysis indicated glomerular proliferation and sclerosis, many crescents, and mild glomerular basement membrane thickening. Immunohistochemical analysis showed granular deposition of complement C3, immumoglobulin G (IgG), IgG1, and PLA2R along the glomerular capillary loops. Electron microscopy revealed electron-dense deposits in the subepithelial area. The renal function of the patient recovered and proteinuria was significantly reduced after treatment. A literature review retrieved 33 cases that mostly presented with heavy proteinuria, hematuria, and acute renal insufficiency. Pathological evaluations revealed necrotizing crescent formation and different membranous changes. Most cases received immunosuppressive therapy, which alleviated proteinuria and azotemia.Conclusion:The occurrence of MN with ANCA-associated NCGN is rare and usually presents in patients with heavy proteinuria, hematuria, and worsening renal function. The age of onset and level of proteinuria are between those for either MN or ANCA-associated NCGN alone. Levels of hematuria and serum creatinine are similar to ANCA-associated NCGN alone. A variable percentage of globally sclerotic glomeruli are related to renal injury. These cases respond differently to immunosuppressive therapy and their prognoses are uncertain. Now the sample size of MN with ANCA-associated NCGN is small and lack of experience for diagnosis and treatment. In the future we need to collect more cases to better diagnosis and treat these diseases.