Successful Treatment of Factor IX Inhibitor Complicated by Nephrotic Syndrome with Rituxan.

Nephrotic syndrome is a well known complication of the development of inhibitors in factor IX patients. Nephrotic syndrome has been treated with Rituxan as have factor IX inhibitors. We present a 4 year old male diagnosed with severe factor IX deficiency at 5 months of age after severe bruising.

History: Between 11/05 and 5/06 we treated a 3 yo male with history of factor IX deficiency and inhibitor as well as nephrotic syndrome with Rituxan. The child received 4 weekly doses of Rituxan at 375 mg/M², followed by monthly doses at 375 mg/M², for six months. He received monthly doses of IVIG at 1 gram/M². In the last 2 months of the course, he was reexposed to factor IX (Alphanine).

Results: He has had no signs of an inhibitor and is on 3x per week dosing. He did redevelop nephrotic syndrome 17 months later but has since been placed in remission on a repeat course of Rituxan.

Conclusions: This is the first report of the successful treatment of both a Factor IX inhibitor and Nephrotic syndrome with Rituxan therapy.