A case of necrotizing glomerulonephritis presenting with nephrotic syndrome associated with pulmonary cryptococcosis

We describe a 68-year-old man with necrotizing glomerulonephritis who presented with nephrotic syndrome accompanied by pulmonary cryptococcosis. He developed rheumatoid arthritis in July 1999 and was treated with low-dose prednisolone. He was admitted to our hospital on November 22 following the appearance of bilateral leg edema in October 2000. Laboratory tests at presentation revealed nephrotic syndrome with renal impairment. Renal biopsy specimens revealed necrotizing glomerulonephritis with crescent, but immunofluorescence study showed lack of staining for immunoglobulins or complement components. Chest X-ray and CT showed abnormal shadows in the right upper lung field, and Cryptococcus neoformans was isolated in a transbronchial lung biopsy. After the diagnosis of pulmonary cryptococcosis was made, the patient was treated with 200 mg/day fluconazole. The pulmonary abnormal shadows immediately improved and urinary protein excretion dramatically decreased. A second renal biopsy, performed about 2 months after the first biopsy, showed disappearance of crescent. Electron microscopic examination of the second renal biopsy showed partial effacement of foot processes without electron-dense deposits. Our findings suggest that necrotizing glomerulonephritis with nephrotic syndrome in this patient represented pauci-immune T-cell-mediated injury related to pulmonary cryptococcosis.