Detection of anti-HIV-1 IgG antibodies in whole saliva by GACELISA and Western blot assays

East Afr Med J. 1996 May;73(5):292-4.

Abstract

The present study, based on 158 HIV seropositives and 167 HIV seronegatives, demonstrates that saliva collected with the Omni-SAL device and tested with GACELISA (an IgG antibody capture ELISA) is an effective non-invasive alternative to serum for anti-HIV IgG antibody screening. The study also shows that a conventional serum Western blot kit can be used, with slight modifications, for confirmatory testing of saliva specimens. Collecting saliva with the Omni-SAL device had a very good acceptance rate among Tanzanian subjects, and although this diagnostic method is not yet known by the general public, 65% of the study participants preferred to give saliva instead of blood for HIV testing.

PIP: In Dar es Salaam, Tanzania, health workers at Muhimbili Medical Centre collected serum and saliva samples from 135 HIV-positive persons attending the AIDS Clinical Trial Clinic, 130 people who came for voluntary HIV testing, and 60 hospital patients. Researchers aimed to assess the suitability of the Omni-SAL device in collecting saliva and the sensitivity, specificity, and feasibility of detecting HIV-1 IgG antibodies in saliva using GACELISA (an IgG capture ELISA) and Western blot assays. Laboratory personnel optimized Western blot for confirmatory testing of saliva specimens by using a biotin/avidin detection as suggested by McMahan and Hofman. All 135 patients attending the AIDS Clinical Trial Clinic, 8 (6.15%) people undergoing voluntary HIV testing, and 15 (25%) of hospital patients tested positive for HIV (total = 158). GACELISA detected all HIV-1 seropositive individuals and did not detect HIV-1 in any of the HIV-1 seronegative individuals (sensitivity 100%; specificity 100%). The saliva optical density to cut-off value for the HIV-1 seropositives was 5.26-9.82, indicating no ambiguity in the results. All saliva specimens on GACELISA reacted strongly to HIV-1 viral proteins Env, Pol, and Gag on the Western blot optimized for testing saliva specimens. It took more than 10 minutes to saturate the collecting pad (Omni-SAL) in 2% of individuals. Saturation of the collecting pad took less than 3 minutes in most cases (64%). Most individuals preferred saliva to be collected for HIV testing than serum and urine (65% vs. 23% and 12%, respectively). 96% of all individuals thought the Omni-SAL device to be easy. These findings suggest that saliva is an adequate specimen for screening and diagnosis of HIV infection. Since many saliva samples can be collected quickly, easily, and safely, Omni-SAL and GACELISA can be done under any field situation by people with minimal training.

Publication types

  • Clinical Trial
  • Controlled Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Blotting, Western / methods*
  • Enzyme-Linked Immunosorbent Assay / methods*
  • HIV Antibodies / analysis*
  • HIV Seropositivity / blood
  • HIV Seropositivity / diagnosis
  • HIV-1 / immunology*
  • Humans
  • Immunoglobulin G / analysis*
  • Patient Acceptance of Health Care
  • Saliva / virology*
  • Sensitivity and Specificity
  • Tanzania

Substances

  • HIV Antibodies
  • Immunoglobulin G