Document 2733
 DOCN  M94A2733
 TI    Performance of a new commercial test to measure HIV p24 antigen
       utilizing acid dissociation.
 DT    9412
 AU    Sherlock CH; Karakas L; Craib KJ; University of British Columbia, St
       Paul's Hospital, BC Centre for; Excellence in HIV/AIDS, Vancouver,
       Canada.
 SO    Int Conf AIDS. 1994 Aug 7-12;10(1):237 (abstract no. PB0376). Unique
       Identifier : AIDSLINE ICA10/94369842
 AB    OBJECTIVE: To assess the performance of a new HIV p24 antigen ELISA
       (Coulter Corporation) and to compare this with the test of record in
       North America (Abbott HIVAG-1). METHODS: 500 banked frozen sera were
       selected from patients who were HIV antibody (ab) and HIVAG-1 positive.
       200 sera were selected from HIVAb negative patients with no risks for
       HIV infection. All sera were tested by Coulter HIV-1 p24 antigen assay
       (C-p24) both before and after acid dissociation by the Coulter ICD Prep
       Kit (ICD). All repeat positives were neutralized with Coulter's p24
       neutralization assay (C-neut). Those that did not neutralize were called
       negative. All Coulter tests were quantified in pg/ml; only 56 sera were
       quantified by HIVAG-1. RESULTS: Of 500 HIVAG-1 positive sera, 423 (85%)
       repeated C-p24 positive; of these, 405 were C-neut positive. After ICD,
       497 (99.4%) repeated positive; all were C-neut positive. 2 of the 3 ICD
       C-neut negatives were also C-p24 negative; 1 was low positive. Of the
       200 HIV Ab negative sera, all were negative by both C-p24 and after ICD.
       If Coulter ICD is taken as the test of reference, the C-p24 is 82%
       sensitive and 99.5% specific. If HIVAG-1 is the test of reference, the
       sensitivity of C-p24 is 81% and of ICD is 99.4%. The correlation
       coefficient (r) between both C-p24 runs was 0.97, also for both ICD
       runs. The correlation coefficient between C-p24 and HIVAG-1 on 56
       quantified sera was 0.86 but the C-p24 concentrations were significantly
       higher than the HIVAG-1 concentrations (ratio 1.4;p < .001, paired t
       test). The ratio of mean ICD concentrations to mean C-p24 concentrations
       was 5.8. DISCUSSION AND CONCLUSIONS: There would be little merit in
       using C-p24 since its sensitivity is low compared with its own ICD
       performance and with HIVAG-1. Coulter ICD results show excellent
       sensitivity, specificity and reproducibility with mean p24
       concentrations 5.8 times those with C-p24.
 DE    Antigen-Antibody Complex/IMMUNOLOGY  Comparative Study  Enzyme-Linked
       Immunosorbent Assay/*METHODS  Human  HIV Core Protein p24/*BLOOD  HIV
       Seronegativity/IMMUNOLOGY  HIV Seropositivity/*DIAGNOSIS/IMMUNOLOGY
       HIV-1/*IMMUNOLOGY  Predictive Value of Tests  Reproducibility of Results
       MEETING ABSTRACT

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