Anti-HIV antibodies in patients receiving intravenous immunoglobulin

Until recently, donors of serum for intravenous immunoglobulin (IVIG) were not screened for the presence of antibodies to the human immunodeficiency virus (HIV). We detected anti-HIV antibodies (Ab) in the sera of seven patients following IVIG infusions. In addition, enzyme immunoassay values increased and/or Western blot converted from negative to positive in all patients following infusions and declined again over time confirming passive acquisition. Patients who received IVIG manufactured after the screening of donors was initiated may still test positive for anti-HIV Ab due to antibodies to human T-lymphocyte cell lines in which viral antigen was prepared. Such false positives must be excluded when testing IVIG recipients. Despite the presence of antibodies to HIV, IVIG has never been documented to transmit the virus.