Distribution of hepatitis A antibody over a process for the preparation of a high-purity factor VIII concentrate

The levels of hepatitis A antibody were studied in factor VIII products manufactured by the Scottish National Blood Transfusion Service. It was found that the current high-purity factor VIII product has no detectable hepatitis A antibody, whereas the superseded intermediate-purity product had significant antibody levels (6,700 mIU/ml). Although the finished high-potency factor VIII product has no detectable hepatitis A antibody, significant levels of antibody are found in the early stages of product manufacture. This antibody may offer some protection against hepatitis A contamination present in very occasional plasma donations. Antibody to parvovirus B19 is also present at intermediate stages in the manufacture of high-potency factor VIII, but its significance is not known. Hepatitis A antibody levels were also measured in normal immunoglobulin. These data indicate that antibody levels in the plasma pools used to manufacture factor VIII are falling.