Plasma derivatives and viral hepatitis.

Plasma derivatives can be separated into those with either a low or a high risk of transmitting viral hepatitis. Low-risk products, with few exceptions, will remain low-risk irrespective of the plasma from which they are manufactured because they are heated at 60 degrees C for 10 hours (Albumin, Plasma Protein Fraction) or because they contain protective antibodies (Immune Globulin). This would appear to be the case not only for hepatitis B but also for non-A, non-B hepatitis. The risk of hepatitis B associated with plasma derivatives is reduced but not eliminated by HBsAg screening of donors. Further decreasing the risk of hepatitis B associated with AHF or Factor IX lots, as well as newer products like AT-III, alpha-1 antitrypsin, Fibronectin, C-1 Inactivator, and Factor XIII, may be accomplished either by the combination of stabilization and heating or by assuring that these products contain an excess of anti-HBS. For highly-purified products with little residual immunoglobulin it may be necessary to add anti-HBs. The addition of antibodies against non-A, non-B hepatitis agents when they are identified, could prevent transmission of both forms of viral hepatitis by plasma derivatives. Methods to stabilize and heat high-risk plasma derivatives to inactivate hepatitis viruses have the potential to remove both hepatitis B and non-A, non-B hepatitis infectivity.