RESUMO
We report a case of anti-neutrophil cytoplasmic antibody(ANCA)-associated rapid progressive glomerulonephritis (RPGN) that was treated with intravenous immunoglobulin (IVIg) therapy. A 37-year-old woman was admitted to our hospital because of a low-grade fever, general malaise, and a poor appetite. At the time of admission, her renal function had severely deteriorated (serum creatinine level 9.5 mg/dl; mean Ccr 3.3 ml/min) and she had severe anemia (Hb 6.6 g/dl). An immunological examination revealed the presence of ANCA-associated RPGN. A biopsy confirmed a diagnosis of pauci-immune-type necrotizing crescentic glomerulonephritis. After initial treatment with steroid pulse therapy (methylprednisolone, 1,000 mg/day x 3 days), her general condition deteriorated and two sessions of hemodialysis were required. On the 10th hospital day, a high dose of immunoglobulin was administered intravenously (IVIg 400 mg/kg/day x 5 days). This therapy immediately improved her general condition and lowered her serum titer of MPO-ANCA and her serum creatinine level. After two IVIg treatments, her MPO-ANCA titer returned to a normal level and her serum creatinine level improved from 9.5 mg/dl to 3.3 mg/dl. A second biopsy confirmed clinical improvement. These findings suggest that IVIg therapy is effective for cases of ANCA-associated glomerulonephritis that are difficult to treat using conventional immunosuppressive therapy.