title: The significance of western blot assays indeterminate for antibody to HIV in a cohort of homosexual/bisexual men. The Multicenter AIDS Cohort Study.
abstract: The objective of this study was to determine the frequency and significance of nondiagnostic Western blot (WB) assays in homosexual/bisexual men at risk of infection with HIV-1. The presence of a positive enzyme-linked antibody assay (EIA) confirmed by a positive WB was used as evidence of infection and seroconversion. Indeterminate WB assays were defined as reactions to only one viral gene product of HIV-1. Three analyses were conducted to (a) determine the frequency of such reactions in men who, during a 4-year period, did not develop diagnostic serologic reactions; (b) determine, retrospectively, the preseroconversion frequency of indeterminate WB assays in 286 men who seroconverted; and (c) evaluate in vitro production of specific antibody by peripheral blood mononuclear cells (PBMCs) as a method of indicating whether or not an indeterminate WB assay represents HIV-1 infection. Reactions to products of gag, pol, or env were noted in 8.0, 4.0, and 6.7% of 1,595 first-visit tests of men who remained seronegative for 4 years. Indeterminate reactions occurred in 204 men with negative EIAs who subsequently seroconverted and in 82 men with positive EIAs preconversion. Supernatants harvested from PBMCs of 2 of 36 seroconverters obtained one or two visits preseroconversion and cultured with pokeweed mitogen were antibody-positive. All were positive at the visit, with diagnostic serology. None of the supernatants from cells of 19 men with EIA-negative WB-indeterminate serologic assays were antibody-positive. Our results suggest that persistently EIA-negative homosexual/bisexual men who have indeterminate WB assays are unlikely to be infected with HIV-1.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Howard Brown Memorial Clinic, Northwestern University Medical School, Chicago, Illinois 60611.
authors.forename: J
authors.initials: J
authors.lastname: Phair
authors.forename: D
authors.initials: D
authors.lastname: Hoover
authors.forename: J
authors.initials: J
authors.lastname: Huprikar
authors.forename: R
authors.initials: R
authors.lastname: Detels
authors.forename: R
authors.initials: R
authors.lastname: Kaslow
authors.forename: C
authors.initials: C
authors.lastname: Rinaldo
authors.forename: A
authors.initials: A
authors.lastname: Saah
mesh_terms: D001727:Bisexuality; D015153:Blotting, Western / Q000379:methods*; D015704:CD4 Antigens / Q000032:analysis; D015331:Cohort Studies; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D015686:Gene Products, env / Q000276:immunology; D015683:Gene Products, gag / Q000276:immunology; D015684:Gene Products, pol / Q000276:immunology; D005814:Genes, Viral; D015752:Genes, env; D015750:Genes, gag; D015751:Genes, pol; D015483:HIV Antibodies / Q000097:blood*; D006679:HIV Seropositivity / Q000097:blood* / Q000276:immunology; D015497:HIV-1 / Q000235:genetics; D006716:Homosexuality; D006801:Humans; D008297:Male; D016176:T-Lymphocyte Subsets / Q000276:immunology
chemical_list: D015704:CD4 Antigens; D015686:Gene Products, env; D015683:Gene Products, gag; D015684:Gene Products, pol; D015483:HIV Antibodies