PREVALENCE OF ANTIBODIES AGAINST AN IMMUNODOMINANT REGION OF THE HIV-1 ENVELOPE GLYCOPROTEIN GP41 IN SERA FROM HIV-1-INFECTED INDIVIDUALS IN BRAZIL

Findings are reported from a study conducted with plasma from HIV-1 positive individuals resident in Brazil to determine whether sera from Brazilian HIV-1 infected individuals react with the gp41 immunodominant epitope to a comparable degree as do North American/European sera. 120 plasma samples were collected at different hospitals in Rio de Janeiro during 1990-93 from HIV-1 seropositive individuals in all stages of the infection and analyzed. The subjects were participating in a multicenter study of heterosexual HIV transmission in the city. An additional 18 plasma from HIV-1 seronegative individuals from the same risk groups and three normal plasma from blood donors were used as controls. It is concluded upon analysis that a diagnostic assay based upon use of a synthetic peptide corresponding to the envelope gp41 immunodominant epitope must be carefully screened with local HIV-1 positive plasma banks before introduction to commercial use. The use of a shorter peptide, however, comprising the sequence CSGKLIC identified as the minimum epitope may increase sensitivity of the assay, as it appears to be most conserved between different HIV-1 isolates. Brazilian HIV-1 isolates should be analyzed to verify if they conform to this rule.