Cryofiltration apheresis in the United States.

There are approximately 2,000 cases of cryoglobulinemia reported each year in the United States. The number of cases has been and is expected to continue growing exponentially since the advent of its association with the hepatitis C virus (HCV). Cryofiltration apheresis is a specific therapy for the treatment of cryoprotein induced diseases that selectively removes cryoprecipitates. We are currently the only center in the United States performing cryofiltration apheresis. We report on 32 patients treated with over 920 cryofiltration apheresis procedures over the last 6 years under the Investigational Device Exemption of the Food and Drug Administration Office of Orphan Devices. Twenty-seven patients were treated for cryoglobulinemia. Twelve of these patients received maintenance cryofiltration apheresis at some point, and 5 patients died. Five of the 32 patients were treated for cold IgM agglutinin disease. Only 2 of these patients, having plasma positive for cryoprotein and a high titer antibody, responded to therapy. None of these patients received maintenance therapy. No complement activation was observed using the cryofilter by measuring C3a and C5a. Although cryoproteins were effectively removed from the plasma, the other vital proteins such as immunoglobulins, albumin, and fibrinogen were preserved. Therefore cryofiltration apheresis is safe and effective in treating cryoprotein induced diseases. We would like to see widespread use of this cryofilter so that all patients with cryoprotein induced diseases such as cryoglobulinemia may benefit from this procedure.