A case of rheumatoid arthritis with immunotactoid glomerulopathy

The patient was a 64-year-old female who had been treated by a local doctor for rheumatoid arthritis and hypertension for 10 years. Malaise and edema developed since July, 1990, and as proteinuria and renal dysfunction were noted, the patient was admitted to our hospital on November 2. On admission, BUN was 33mg/dl, creatinine was 2. 5mg/dl, and proteinuria was about 3g/day. Renal biopsy was performed after admission. Light microscopy revealed nodular lobulation of glomeruli and occlusion of loops. Dylon staining was negative. Immunofluorescent study showed granular deposition of IgG, IgM, C3, C4, Clq in the glomerular basement membrane and mesangial area. Electron microscopy showed a large amount of electron dense depositsin the subendthelium and mesangial area and dense aggregation of tubular structure in the deposit, part of which exhibited a profile of fingerprint deposit. The tubular structures were classified into three major types, which were 120, 100, and 50nm in diameter. From these findings, a diagnosis of immunotactoid glomerulopathy was made. After renal biopsy, plasmapheresis and prednisolone were administered, and the patient has been managed conservatively to date.