CLINICAL-EXPERIENCE WITH POLYELECTROLYTE-FRACTIONATED PORCINE FACTOR-VIII CONCENTRATE IN THE TREATMENT OF HEMOPHILIACS WITH ANTIBODIES TO FACTOR-VIII

  • 1 January 1984
    • journal article
    • research article
    • Vol. 63  (1) , 31-41
Abstract
Circulating antibodies to factor VIII (anti-VIII, inhibitors) occurring in patients with hemophilia neutralize porcine factor VIII less readily than human factor VIII in vitro. Over an 18-mo. period, 8 patients with anti-VIII were treated with 45 courses (297 infusions) of polyelectrolyte-fractionated porcine factor VIII concentrate (PE porcine VIII). Where no anti-PE porcine VIII was detectable, mean postinfusion rise in plasma fator VIII was 1.29 U/dl per U infused/kg. Above 13 Old Oxford U of anti-PE porcine VIII and 48 Bethesda U of anti-human VIII, there were no postinfusion rises in plasma factor VIII. Where postinfusion rises were detected, clinical responses were good and conventional methods could be used to guide dosage. Ten percent of infusions were followed by febrile reactions, but these were unusually mild and decreased in frequency and severity with increasing exposure. Multiple and prolonged courses of therapy were given to some patients without evidence of loss of clinical or laboratory efficacy. PE porcine VIII could provoke anamnestic rises of anti-VIII in susceptible patients, but appeared to have a lower immunogenic potential than human VIII. PE porcine VIII is a rational and effective therapeutic alternative for patients with anti-VIII, particularly those with intermediate level inhibitors who cannot be managed effectively using human factor VIII.