[Clinical evaluation of a new factor VIII concentrate in hemophilic children].

Studies of in vivo recovery, longevity and dose response of factor VIII following infusions of a new factor VIII concentrate (Koate, Cutter Laboratories) yielded results similar to those reported using other sources of factor VIII. Koate has been demonstrated to be clinically effective in classic hemophilia. This preparation was produced by refinements of the methods first described by Hershgold, Pool and Pappenhagen in 1966. By these procedures a high purity factor VIII concentrate is obtained being some 65 to 170 fold purified. This factor VIII concentrate was clinically evaluated in 11 hemophilic children (one of them with 7 Bethesda Units inhibitor) who received a total of 13 separate infusions. Biologic half-life values determined in two subjects resulted 12 and 9,5 hours comparing favorably with those previously reported. Initial 50% disappearance averaged 5,4 and 4,8 hours respectively. In vivo recovery of the infused factor VIII activity averaged 98 +/- 12,75%. Dose response measurements showed that 1 unit/Kg gave an in vivo increase in circulating activity of 1,97 +/- 0,93%.