Successful treatment with steroid pulse therapy in a case of immunotactoid glomerulopathy with hypocomplementemia.

We report a case of immunotactoid glomerulopathy with severe hypocomplementemia. The patient was a 47-year-old woman who presented with pitting edema, proteinuria, and hypertension. Serological testings were negative or within normal limits except for hypocomplementemia. There were no findings of hematopoietic diseases, cryoglobulinemia, and systemic lupus erythematosus. The renal biopsy specimen showed membranoproliferative glomerulonephritis with numerous periodic acid-Schiff (PAS)-positive deposits. Under electron microscopy, however, microtubular structure was shown in the mesangial matrix and the subendothelial and subepithelial spaces of the peripheral capillary loops. These histological features were compatible with those of immunotactoid glomerulopathy. Although conventional oral steroid therapy failed to have an effect on proteinuria and hypocomplementemia over 3 months, steroid pulse therapy brought dramatic relief: complete remission of proteinuria and normalization of hypocomplementemia. These findings suggest that intensive immunosuppressive therapy may cure a kind of immunotactoid glomerulopathy with hypocomplementemia.