Purity of factor VIII concentrates and serial CD4 counts. The Transfusion Safety Study Group.

Whether expensive high-purity factor VIII concentrates are required to slow CD4 decline in HIV-infected haemophiliacs is controversial. We examined CD4 counts among such cases treated with intermediate-purity and high-purity factor VIII. 36 subjects treated with high-purity concentrate for 6 months or more had a smaller decline in CD4 than 72 matched controls on intermediate-purity concentrate (two-sided p = 0.08). In a more complex analysis with 226 subjects, CD4 counts declined 3% less per 6 months with high-purity material than with intermediate product (p = 0.04). Thus concentrate purity may affect rate of CD4 change.