False human immunodeficiency virus test results associated with rheumatoid factors in rheumatoid arthritis

To investigate if immunological factors associated with rheumatoid arthritis (RA) affect the result of human immunodeficiency virus (HIV) screening by electrochemiluminescence immunoassay (ECLIA) and enzyme-linked immunosorbent assay (ELISA).

100 RA cases were enrolled from January 2012 to February 2013 into this study. HIV screening was conducted with ECLIA detecting both HIV-1 p24 antigen, HIV-1 and HIV-2 antibodies, with ELISA and colloidal gold method detecting HIV-1 and HIV-2 antibodies. The samples producing positive results were submitted to the Center for Disease Control for confirmation using Western blotting method. The antibody titers of rheumatoid factors (RF) including RF-IgG, RF-IgM, RF-IgA, and CCP-IgG were analyzed by ELISA.

The HIV positive-rate determined by ECLIA was significantly higher than that by ELISA and colloidal gold method (P<0.01). The false-positive rate of HIV screening was associated with antibody titers of RF-IgG, RF-IgM, RF-IgA, and CCP-IgG in RA (P<0.01).

Immunological factors, including RF and anti-CCP antibody, may influence the screening of HIV by ECLIA, producing false-positive result.