Studies on the Usefulness of Saliva for Detection of Antibodies to HIV-1

It has been reported that antibodies to HIV-1 could be detected in saliva of patients with AIDS. We studied whether saliva is potentially useful for screening of HIV-1 infected persons. Pairs of serum and saliva were collected from both 19 HIV-1 seropositive outpatients (CDC type, II:15, III:1, IV:3) of AIDS clinic in our hospital and 4 controls. Multiple saliva collection was done from seropositives periodically for 8 months after the first sampling. Serum and saliva were tested with ELISA and Western blot (WB) methods by using kits of diagnostics Pasteur (ELAVIA MIXT and LAV Blot-1). All pairs of serum and saliva from controls were clearly negative by ELISA. Nineteen sera of proven seropositive cases and paired 18 saliva samples were confirmed to be positive in ELISA test employed, but O.D. value of 1 saliva sample was below the cut-off level. However, in the follow-up study, samples taken from the same individuals after the first sampling showed positive results. Forty-seven saliva samples from seropositives were served for the WB test. Clearly positive bands were observed in 43 samples. In each of the remaining 5 samples, the final decision was "indeterminate", although a strong reactive band was observed at GP-160. The results mentioned above suggested that saliva was useful for screening of antibodies to HIV-1 in epidemiological studies, though it is necessary to improve the sensitivity of ELISA and WB for tests of saliva.