A Case of C-ANCA Positive Rapidly Progressive Glomerulonephritis Associated with Polyclonal Gammopathy

Rapidly progressive glomerulonephritis(RPGN) is one of the most calamitous renal disease which is clinically characterized by sudden and relentless deterioration in renal function within weeks to months and associated with the pathologic finding of extensive extracapillary proliferation. Pauci-immune RPGN is mostly associated with anti neutrophil cytoplasmic antibody (ANCA) positive systemic vasculitis, but renal-limited RPGN may be found in part. We experienced a case of ANCA positive RPGN associated with polyclonal gammopathy without systemic symptoms. A 64-year-old woman was admitted with gross hematuria and azotemia. Laboratory findings revealed polyclonal gammopathy and severe anemia without definite cause, and she was diagnosed as C-ANCA positive crescentic glomerulonephritis without systemic vasculitis. She was treated with steroid pulse therapy and her renal function and anemia were progressively improved. We report herein a rare case of C-ANCA positive crescentic glomerulonephritis associated with polyclonal gammopathy and severe anemia with the review of literature.