Diagnosis of HIV-1 infection with whole saliva by detection of antibody IgG to HIV-1 with ultrasensitive enzyme immunoassay using recombinant reverse transcriptase as antigen

Whole-saliva samples were collected from 45 asymptomatic carriers, 18 patients with AIDS-related complex (ARC) or AIDS, and 76 medical students by simple spitting with no stimulation and tested by an ultrasensitive enzyme immunoassay (immune complex transfer enzyme immunoassay) for anti-HIV-1 IgG using recombinant reverse transcriptase as antigen and beta-D-galactosidase as label. With as little as 1 microliter of whole saliva, the lowest signals among the 45 asymptomatic carriers, 8 patients with ARC, and 10 patients with AIDS were 38-, 78-, and 3-fold, respectively, higher than the highest signal among the medical students. When the volume of whole saliva for test was increased up to 100 microliters, no significant effect was observed on signals for seropositive cases and signals for the medical students increased only very slightly. Therefore, whole-saliva samples containing extremely low levels of anti-HIV-1 IgG, even 2,000-fold lower than the lowest level among the 45 asymptomatic carriers tested, were considered to be discriminated from those of seronegative individuals. Thus, the sensitivity and specificity were expected to be both 100% with whole saliva even for a larger number of samples, although the number of samples tested was limited.