Antiidiotypic responses to immunization with anti-Leu 3a in human immunodeficiency virus-seropositive individuals.

Anti-idiotypic antibodies to anti-CD4 monoclonal antibodies (MAbs) have been reported to bind to the human immunodeficiency virus (HIV) envelope glycoprotein gp120. To establish whether HIV-infected patients can mount an anti-idiotypic response to murine MAb, four individuals with symptoms of AIDS-related complex (ARC) were immunized over 10 weeks with six intramuscular injections of anti-Leu 3a (1 mg). Despite their immunocompromised state, all patients made anti-constant region and anti-idiotypic antibodies, although the amplitude of the responses varied between individuals. No significant toxic or allergic reactions were seen, and there were no changes in clinical status during the 6 months after immunization. No increase in serum HIV-neutralization titers was seen, and purified anti-idiotypic antibodies did not bind gp120.