Crescentic glomerulonephritis with antimyeloperoxidase antibodies developing during the course of IgA nephropathy in a patient with rheumatoid arthritis.

Abstract Glomerulonephritis, such as membranous nephropathy, IgA nephropathy, and p-antineutrophil cytoplasmic autoantibody (ANCA)-related crescentic glomerulonephritis, has been shown to occur in rheumatoid arthritis (RA). However, the occurrence of two types of glomerulonephritis in a patient with RA is rarely observed. Here, we describe a patient with RA who developed crescentic glomerulonephritis with antimyeloperoxidase (MPO) antibodies during the course of IgA nephropathy. This case indicates that crescentic glomerulonephritis and IgA nephropathy may occur together in association with p-ANCA in RA.