Anti-HIV-1 seroreactivity and HIV transmission route[R1]

Background: antibody binding assays carried out by our group have consisten tly indicated a higher reactivity of sera from male HIV-1 infected individu als. This study was carried out in order to analyze the importance of gende r, route of transmission, disease progression and HIV-1 genotype in serorea ctivity assays. Study design: specificity of antibody binding was studied in plasma of 247 HIV-1 seropositive individuals belonging to patient groups of pregnant wome n, injecting drug users (IDUs) and recent seroconvertors, resident in Rio d e Janeiro, RJ. Recognition of synthetic peptides corresponding to antigenic ally important epitopes in the envelope of HIV-1 (gp41 immunodominant epito pe, V3 loop, V2 loop and gp41 735-752 epitope) was determined. Results: the immunodominant gp41 peptide (amino acids 594-613, HIV-1 MN seq uence) was recognized by 85% of all plasma tested. Reactivity with the gp41 735-752 peptide and gp120 V2 loop peptides was low but quite variable, bei ng generally more often specific to a Brazilian V2 peptide used than to the HIV-1 MN derived V2 peptide. The overall recognition of the different V3 p eptides tested varied from 41 to 76%. Patients with more advanced disease s howed a more frequent reactivity with the peptides studied than did asympto matic patients. Statistically significant differences in peptide recognitio n were observed by multiple logistic analyses comparing plasma derived from individuals infected by blood or sexual HIV transmission, adjusting for di sease progression and gender. Plasma from individuals infected by sexual tr ansmission showed lower peptide recognition than did plasma from individual s infected through HIV positive blood. Association attempts between serorea ctivity and genotype indicated that plasma derived from patients infected w ith HIV-1 of the F subtype showed highest recognition of heterologous V3 pe ptides, as well as a slightly more frequent recognition of the non-V3 pepti des tested. Recognition of homologous peptides was generally higher than re cognition of heterologous peptides. Differences were most pronounced betwee n the prototypical HIV-1 B subtype and the Brazilian B " variant of this su btype but almost non-existent between the HIV-1 B and F subtypes. Conclusions: individual gender was shown to be a confounder when investigat ing the relationships of peptide reaction to HIV-1 route of transmission th rough multivariate statistical methods: patients infected by blood transmis sion (IDU) present higher frequency of peptide recognition than individuals infected by sexual HIV-1 transmission. Plasma from individuals infected wi th the B " variant (GWG) of B subtype HIV-1 showed lower heterologous pepti de recognition than that from HIV-1 B (GPG) or F infected individuals. (C) 1999 Elsevier Science B.V. All rights reserved.