Summary
Immune tolerance has by several methods been induced in
haemophiliacs with antibodies. A conversion of “high responders” into “low responders”
was previously reported after repeated moderate factor IX doses over periods of 7-10
days in
combination with cyclophosphamide and steroids in two patients with haemophilia B
and inhibitors. This paper reports similar results in a heamophilia A patient by giving
factor VIII, cyclophosphamide, and steroids during relatively short periods of time
(7-8 days). The anamnestic response markedly decreased already following the first
treatment and never exceeded a level of 1 u/ml (˜ 3 BU/ml) even when boosted with
ordinary factor VIII doses for only 3 days. It is concluded that the markedly decreased
secondary antibody response is most probably the result of factor VIII given at short
intervals (twice a day) for periods of up to about one week when given in combination
with cyclophosphamide and steroids. The same effect may be achieved by other methods.
The treatment schedule suggested in the present paper is, however, simple and avoids
long periods of high antibody levels. Furthermore, the total factor VIII dose used
is lower than suggested in most other treatment schedules, which makes the treatment
substantially less expensive.
Key words
FVIII: C antibodies - FVIII-concentrate - Corticoids - Cyclophosphamide - Haemophilia
A - Immunosuppressive therapy - Induced immunotolerance
