       Document 2681
 DOCN  M94A2681
 TI    IgA and IgM antibody capture gelatin particle adsorption test for
       anti-HIV.
 DT    9412
 AU    Petchclai B; Khupulsup K; Warachit P; Mahidol University, Virus Research
       Inst. Chiengral Hosp.; Thailand.
 SO    Int Conf AIDS. 1994 Aug 7-12;10(1):249 (abstract no. PB0426). Unique
       Identifier : AIDSLINE ICA10/94369894
 AB    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.
 DE    Agglutination Tests/*METHODS  AIDS Serodiagnosis/*METHODS  Female  Human
       HIV Antibodies/*BLOOD  HIV Seropositivity/*DIAGNOSIS/IMMUNOLOGY
       IgA/*BLOOD  IgM/*BLOOD  Infant, Newborn  Predictive Value of Tests
       Pregnancy  Pregnancy Complications, Infectious/DIAGNOSIS/IMMUNOLOGY
       Prenatal Care  Substance Abuse, Intravenous/IMMUNOLOGY  Thailand
       MEETING ABSTRACT

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).

