Gammagard and reported hepatitis C virus episodes.

Since first licensed in the United States in 1986, Gammagard, an intravenous immunoglobulin produced by the Hyland Division of Baxter Healthcare Corporation, had been considered an effective and safe form of immunoglobulin. Its safety had been proved in patients with immunoglobulin A (IgA) deficiency, including those with the complication of anti-IgA antibodies. However, in early 1994, there were reported episodes of hepatitis C virus transmission associated with administration of Gammagard manufactured during April 1993 and thereafter. The investigations into the mechanisms to account for these events, including the manufacturing processes, are reviewed. The results of studies and analyses by both Baxter and the US Food and Drug Administration, including first- and second-generation enzyme-linked immunosorbent assays, polymerase chain reaction analyses, and the solvent-detergent viral-inactivation manufacturing step, are discussed. Evaluations of donor histories identified a group of donors who contributed to three target lots of the agent and who were subsequently excluded from donor pools. The classification scheme and criteria for all patient reports of hepatitis associated with administration of Gammagard, as well as the classification of all hepatitis C virus episodes, are presented.