Immunoadsorption of factor VIII inhibitors.
OBJECTIVE
Extracorporeal immunoadsorption is being increasingly applied in a variety of disorders. This approach is particularly suited to removal of antibodies or inhibitors to coagulation factor VIII and may be particularly useful before the administration of large amounts of expensive replacement or bypass therapy for patients with hemophilia who are bleeding, or patients undergoing immune tolerance therapy.


RESULTS
In patients with inhibitors to factor VIII, several types of immunoadsorption therapy have been used, although reports are mainly anecdotal, consisting of relatively small numbers of persons. Nonetheless, the findings suggest that immunoadsorption may be clinically effective and cost-effective and should be considered early in the treatment of appropriate patients. New immunoadsorption technologies are being described for a variety of disorders, including hemophilia, and a new synthetic matrix of polystyrene beads functionalized with sulfonate and tyrosyl methylester groups for immunoadsorption removal of factor VIII inhibitors is intriguing.


CONCLUSIONS
Although immunoadsorption was shown to be clinically effective in patients with inhibitors to factor VIII more than two decades ago, recent papers have emphasized the desirability of early implementation of the modality in the treatment plan. Immunoadsorption is relatively easy to perform with few adverse effects, but specialized equipment is required, and it should be performed in an experienced setting. Although potentially less costly than other (bypass) therapies, immunoadsorption is itself not inexpensive, and its comparative effectiveness with plasmapheresis and other management options for the dangerously bleeding patient with antibodies to factor VIII should be determined by multicenter randomized controlled trials. Interesting recent novel technical developments in the field may facilitate increased use of the procedure.
Freedman
John
J
St. Michael's Hospital, University of Toronto, Toronto, Canada. freedman@smh.toronto.on.ca
Garvey
M Bernadette
MB
D005169:Factor VIII / Q000276:immunology*; D006467:Hemophilia A / Q000276:immunology / Q000628:therapy; D006801:Humans; D007163:Immunosorbent Techniques; D007164:Immunosorbents; D007518:Isoantibodies / Q000097:blood / Q000302:isolation & purification*
D007164:Immunosorbents; D007518:Isoantibodies; D005169:Factor VIII