Detection and characterization of hepatitis C virus RNA in immune globulins

Hepatitis C virus (HCV) RNA was measured in immune globulins and its chemical and physical properties were characterized.

The study examined 69 immune globulin lots from 7 manufacturers, including 44 intravenous and 25 intramuscular immune globulin preparations. In addition, 8 experimental intravenous immune globulin preparations were investigated. Detection and quantitation of HCV RNA were achieved by reverse transcription and nested polymerase chain reaction at limiting dilution. A multi-antigen anti-HCV enzyme immunoassay was also used to test these immune globulins.

The highest level of HCV RNA was found in an experimental immune globulin lot derived from a plasma pool made up of 186 anti-c100-3-reactive units. HCV RNA was detected only in 1 of 7 manufacturers' experimental intravenous immune globulin preparations derived from a pool made up of 2887 anti-c100-3-negative units. It was also detected in commercial intravenous immune globulin lots prepared by the same manufacturer from source plasma, but not from recovered plasma. More than half of the commercial intramuscular immune globulin lots, including specific immune globulin products, were HCV RNA positive. All immune globulin products examined were reactive for anti-HCV. Certain similarities were found for HCV RNA present in an immune globulin product and plasma. Ethanol at 20 or 25 percent had no effect upon the buoyant density of HCV RNA.

Many immune globulin preparations contained HCV RNA, with levels depending upon both the type of starting plasma and the manufacturing process. Exposure to ethanol did not appear to affect the physical characteristics of HCV RNA.