Removal and inactivation of hepatitis A virus (HAV) during processing of factor VIII concentrates.

Although hepatitis A virus (HAV) transmission by single donor blood products is a rare event, recent reports have raised concerns about the potential for HAV transmission by pooled plasma products. In this study the removal and inactivation of HAV during production of a factor VIII concentrate, which included solvent-detergent treatment and anion-exchange chromatography steps, was assessed at 5 distinct stages of production using infectivity and, in some cases, isotopic assays. The results of these 'spiking' studies revealed an overall HAV clearance of > 8 log with appreciable contributions from antibody neutralisation, cryoprecipitation, lyophilization and possibly chromatography, but not filtration. In addition it was shown that neither solvent detergent treatment or ion-exchange chromatography reversed or impeded the neutralisation of HAV by antibody.