Analysis of Increased False-Positive ELISA Results for HIV in the Blood of Donors Infected with SARS-CoV-2.

The study examined the effect of IgG antibodies against SARS-CoV-2 virus in the blood of donors after COVID-19 on objectivity of HIV detection in the blood samples with two ELISA variants employing reagents A or B in order to select reliable kits to minimize the false-positive HIV results. Retrospectively, the quality control data of two ELISA kits with reagents A or B developed to detect HIV were analyzed using the control sera together with the results of donor blood tested with both kits, which were collected in the periods from January to December 2022 (n = 55,528) and from January to March 2023 (n = 13,837). From the blood samples obtained in 2023, all the specimens with false-positive HIV results obtained with reagent A were selected (n = 126) together with randomly taken samples of this pool with negative HIV results (n = 345). All selected samples were tested for IgG antibodies against SARS-CoV-2 virus, thereupon the correlation analysis was performed between the samples containing SARS-CoV-2 and those with HIV detected by ELISA reagent A. The data on reactivity of IgG antibodies against SARS-CoV-2 significantly correlated with the false-positive ELISA results for HIV obtained with reagent A (r = 0.451, p < 0.01). In 2023, the share of false-positive ELISA results for HIV obtained with reagent A was 0.91% (126/13,837), which was 6.06-fold greater than the corresponding value in 2022 (0.133% (74/55,528); χ2 = 230.38, p < 0.01). This data echoed the SARS-CoV-2 epidemic resulting in the appearance of antibodies against the virus in the donor blood. At the same time, the number of false-positive ELISA results for HIV obtained with reagent B in 2022 (0.014% (8/55,521)) and in 2023 (0.036% (5/13,837)) were essentially smaller than those obtained with reagent A, and the results obtained with the test kit B did not significantly differ from each other for both time periods. Thus, IgG antibodies against SARS-CoV-2 in the blood of donors after COVID-19 can affect the results of HIV detection by some ELISA reagents and consequently elevate the number of false-positive analyses.