Purity of factor VIII product and incidence of inhibitors in previously untreated patients with haemophilia A.
It has been suggested that ultrapure clotting factor products carry a greater risk for inhibitor development in patients with haemophilia. We compared the incidence of inhibitors in 59 previously untreated patients (PUPs) with severe haemophilia (endogenous factor VIII < 0.01 U L-1) A, who were initially treated with cryoprecipitate or intermediate purified products, with that in 22 patients exclusively treated with monoclonally purified and recombinant factor VIII. Persistent inhibitors were those with 1 Bethesda unit per mL or more, on more than one occasion, combined with a decrease in recovery. Incidences of persistent inhibitors were 17% (10/59) for patients who were treated with cryoprecipitate or intermediate-purity products and 9% (2/10) for monoclonally purified and recombinant factor VIII. Transient inhibitors appeared to develop earlier during treatment with ultrapure products as compared to treatment with intermediate/low-purity products. In conclusion, ultrapure products appear not to carry a higher risk for inhibitor development.
Mauser-Bunschoten
E P
EP
Van Creveldkliniek, University Medical Center, Utrecht, The Netherlands. e.mauserbunschoten@digd.azu.nl
van der Bom
J G
JG
Bongers
M
M
Twijnstra
M
M
Roosendaal
G
G
Fischer
K
K
van den Berg
H M
HM
D000328:Adult; D000906:Antibodies / Q000097:blood / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005169:Factor VIII / Q000009:adverse effects / Q000276:immunology / Q000627:therapeutic use*; D005500:Follow-Up Studies; D006467:Hemophilia A / Q000097:blood / Q000188:drug therapy* / Q000276:immunology; D006801:Humans; D007223:Infant
D000906:Antibodies; D005169:Factor VIII