Comparison of five commercial enzyme-linked immunosorbent assays and Western immunoblotting for human immunodeficiency virus antibody detection in serum samples from Central Africa

Abstract

Detection by five different enzyme-linked immunosorbent assays (ELISAs) of antibody to human immunodeficiency virus (HIV) in sera from three Zairian populations consisting of 1,998 individuals with various risks for HIV infection was evaluated. Sera that were reactive by at least one assay and 10% of the nonreactive serum samples were analyzed by Western blot (immunoblot) by using U.S. Public Health Service interpretation criteria. Sera which were positive by ELISA for detection of antibody to HIV-1 and HIV-2 and negative or indeterminate by HIV-1 Western blot were also analyzed by HIV-2 Western blot. Overall, 443 (22.2%) serum specimens were HIV-1 Western blot positive, 390 (19.5%) had indeterminate HIV-1 Western blot patterns, and no samples were HIV-2 Western blot positive. The sensitivity of the ELISAs ranged from 97.5 to 99.8%, and the specificity ranged from 51.7 to 98.4%. By population group, the negative predictive value ranged from 97.1 to 100%, in contrast to the positive predictive value, which varied from 6.6 to 100%. Follow-up results for sera which were indeterminate for antibody to HIV-1 documented only four seroconversions (6.0%) among 67 individuals at high risk for HIV-1 infection and no seroconversions among 202 individuals at relatively low risk for HIV-1 infection. This study demonstrates the importance of evaluating commercial ELISAs with sera from appropriate geographical regions in order to select the most cost-effective and practical assay for use in that region. Furthermore, the high frequency of indeterminate Western blots for African sera emphasizes the continual need for improved confirmatory assays and interpretation criteria.

Evaluation of commercially available assays for antibodies to HIV‐1 in serum obtained from South African patients infected with HIV‐1 subtypes B, C, and D

“…Such heterogeneity raises questions concerning antigenic diversity and its importance relative to laboratory diagnosis. It has been observed that EIAs sometimes have a lower sensitivity andlor specificity when testing African sera, which also yield frequent indeterminate Western immunoblot reactions [Behets et al, 1991;Urassa et al, 19921. Diagnostic tests based on synthetic peptides derived from the immunodominant gp41 region were also less sensitive when samples from Africa were tested [Lange et al, 19931.…”

Evaluation of a Rapid Immunochromatographic Test for Detection of Antibodies to Human Immunodeficiency Virus

“…Serological tests such as enzyme immunoassays (EIAs), particle agglutination assays (PAs), and Western blotting for the detection of anti-HIV antibodies have been useful in the diagnosis of and screening for HIV infection (2,4,5,12,14). Although EIAs are widely used because of their excellent sensitivities, they are expensive, require complex instrumentation, and are too complex for use in the field.…”

Utility of various commercially available human immunodeficiency virus (HIV) antibody diagnostic kits for use in conjunction with efficacy trials of HIV-1 vaccines

“…Existing confirmatory assays are unlikely to be suitable solutions for this problem. In particular, WBs containing multiple vaccine-induced bands are not readily distinguished from those showing early seroconversion due to infection, especially in populations with a high proportion of preexisting reactivity to p17 and p24 bands (2,7,12) and in the face of vaccineinduced Ab responses. Cheap and specific PCR-based assays for direct detection of infection are not yet available and may not be sufficiently sensitive in the setting of preexisting vaccine-induced immune responses leading to reduced viral loads (9,11,13).…”