Identification of Individuals at Increased Risk for AIDS Among Clinically Asymptomatic Homosexuals and Abusers of Intravenous Drugs

Abstract

Immunological parameters previously shown to constitute an increased risk for progression towards AIDS have been observed in clinically asymptomatic individuals considered to be at risk for this syndrome. These parameters include severely decreased numbers of T helper cells (counts below 400/mm blood for CD4+ cells were detected in 7 out of 33 HIV antibody-positive, asymptomatic homosexuals and in 3 out of 29 HIV antibody-positive, asymptomatic drug abusers) and elevated serum IgA and IgM levels (found in 7 to 30 percent of these subjects). Furthermore, up to 60% of risk group members showed a decreased lymphoproliferative response to tetanus toxoid as compared to only 11% of so-called low responders in the simultaneously tested healthy controls. Finally, the capacity to mount an immune response to viral glycoproteins was found to be impaired in individuals at risk for AIDS, as indicated by a low serum level of antibodies to tick-borne meningoencephalitis virus antigen in recently vaccinated subjects.