腎臓学と治療学ジャーナル

Coexistent Membranous Nephropathy with Doubly ANCA-Associated Crescentic Glomerulonephritis: A Case Report and Review of Literature

Abstract

Sirisak Chanprasert,Wisit Cheungpasitporn*,Ann K Eldred

Introduction: Membranous nephropathy (MN) is the most common causes of the nephrotic syndrome in nondiabetic, Caucasian adults. Pauci-immune necrotizing and crescentic glomerulonephritis (PNCGN) typically present with rapidly progressive glomerulonephritis. Coexistent MN and PNCGN is a rare occurrence. We report a case of both MPO- and PR3-ANCA associated NCGN with MN that presented as rapidly progressive glomerulonephritis. Case presentation: A 46-year-old female presented with nausea and vomiting. On physical examination, the patient was a febrile and normotensive. Blood tests showed acute kidney injury and anemia. Urinalysis demonstrated numerous dysmorphic red blood cells with granular casts and nephrotic range proteinuria. Further testing showed negative ANA, positive anti-dsDNA, PR3-ANCA and MPO-ANCA. Kidney biopsy revealed the diagnosis of concurrent PNCGN with membranous nephropathy. The diagnosis of concurrent ANCA-associated NCGN with Membranous nephropathy was made. High dose intravenous methyl prednisolone was initiated. Unfortunately, the patient developed diffuse alveolar hemorrhage and underwent 6 cycles of plasmapheresis, intravenous Cyclophosphamide and pulse dose steroids with transitioned to oral prednisone and mycophenolate. On follow up, her disease seemed to be well suppressed without dialysis. Conclusion: Membranous nephropathy with PNCGN is a rare concurrent glomerulopathy, and even more rare with both MPO and PR-3 positivity. The diagnosis of MN with PNCGN should be considered in patients who present with RPGN and nephrotic range proteinuria.