Petchclai B, Khupulsup K, Warachit P; International Conference on AIDS.
Int Conf AIDS. 1994 Aug 7-12; 10: 249 (abstract no. PB0426).
Mahidol University, Virus Research Inst. Chiengral Hosp. Thailand.
IgM anti-HIV is a good indicator of early HIV infection and IgA anti-HIV is a good indicator for AIDS in infants and children. Presently Western blot and ELISA are used. In response to a growing demand for simpler and less expensive tests, particularly for early diagnosis of AIDS in infants and children, IgM and IgA antibody capture test which was based on a sound and accepted principle was combined with the reliable HIV sensitized gelatin particles from gelatin particle agglutination (GPA) test (Fujireblo Inc,). Microtiter plate "U" shape were coated with rabbit anti human IgM and, anti human IgA, and washed. Diluted tested sera diluted 1:100 were added to these well, 0.1 ml per well, incubated for one hour and washed. Human IgM and IgA were captured to microtiter plate and IgM anti-HIV and IgA anti-HIV demonstrated by adsorption of sensitized gelatin particles to microtiter plate. Positive reaction was shown as a matt of gelatin particle on the bottom of the well while a botton of gelatin particle indicated a negative reaction. IgM anti-HIV was applied to 216 intravenous drug users(IVDU) and 374 pregnant women attending antenatal care unit. It was found that 105 of IVDU were GPA positive, and 87.6% was positive for IgM anti-HIV. All 111 IVDU that were GPA negative as well as all pregnant women, which were GPA negative, were IgM anti-HIV negative. IgM anti-HIV test in IVDU showed that IgM anti-HIV is rarely missed by GPA, a population where early infection missed by a screening test is anticipated. We are improving and validating the specificity of the tests by removing IgG with protein G and monoclonal antibodies in the capture of IgM and IgA. It had to be certain that IgG anti-IIIV was not absorbed through cross reaction of antibodies used for the capture of IgM and IgA. Gelatin particles were used because we are highly satisfied with its sensitivity, specificity and simplicity. We have a long experiences with antibody capture adsorption tests based on sensitized erythrocytes and latex particles. HIV sensitized colored gelatin particles are much clearer in distinguishing positive from negative results. This principle is freed from competition by high titer IgG antibody common in anti-HIV positive sera. They are simple and inexpensive. The tests are now under a longitudinal study in 50 Thai infants born to anti-HIV positive mothers and the results will be available at the presentation time. Early results from the study in infants have been promising. In conclusion, IgM anti-HIV has no role in early diagnosis in general uses if the screening tests covered IgM anti-HIV as efficient as GPA. The present IgA and IgM anti-HIV tests will of value in the early diagnosis of prenatal HIV infections where facilities and funds are limited while AIDS epidemic is exploding.
Publication Types:
Keywords:
- AIDS Vaccines
- Acquired Immunodeficiency Syndrome
- Animals
- Blotting, Western
- Child
- Enzyme-Linked Immunosorbent Assay
- Female
- HIV
- HIV Antibodies
- HIV Antigens
- HIV Core Protein p24
- HIV Infections
- HIV Seropositivity
- Humans
- Infant
- Longitudinal Studies
- Pregnancy
- Rabbits
- immunology
Other ID:
UI: 102208724
From Meeting Abstracts