Antibodies to factor VIII. V. Patterns of immune response to factor VIII in
hemophilia A
JP Allain and D Frommel
The natural history of factor VIII antibodies was studied in 20 severe,
multitransfused hemophiliacs. Two patterns of humoral immune reactivity
were observed. In one group of ten, who developed antibodies after an
average of 22 cumulative exposure days to factor VIII, the antibody titers
increased after each antigenic stimulation or persisted for years in the
absence of transfusion. These patients were designated as high-responding
hemophiliacs. In the second group of ten patients, the factor VIII
neutralizing activity appeared after a longer exposure period (48 days).
Antibody titers remained low, and there was no significant difference in
individual titers before and 8--20 days following transfusion. Antibody
affinity did not increase after renewed antigenic challenge. This pattern
characterized low-responding hemophiliacs. The latter group of patients
benefited from repeated placement therapy required by the clinical
situation.
Volume 47,
Issue 6,
pp. 973-982,
06/01/1976
Copyright © 1976 by The American Society of Hematology
