To investigate if immunological factors associated with the false HIV screening test results in RA.

Subjects who attended the Rheumatology Outpatient Clinic-Internal Medicine Unit of Guanghua Integrative Hospital, from October 2013 to October 2014, who met the American College of Rheumatology/European League Against Rheumatism Criteria for RA were recruited for the study. 100 subjects with RA were recruited. Each patient underwent clinical examination and blood sampling for assessment of serum HIV screening test and Rheumatoid factors (RF-IgA, -IgG, -IgM) and anti-cyclic citrullinated protein antibodies (anti-CCP) were purified from the plasma and detected by ELISA, Samples were collected and processed using standard protocols and were stored in the same freezer before analysis. RA patients were divided into two groups based on the titters of RF and anti-CCP: RF<18 U/ml/ anti-CCP<25 U/ml group and RF>300 U/ml / anti-CCP>500 U/ml group.HIV screening tests were determined by three methods: ELISA、Immuno-colloidal Golden Method and ECLIA.The positive results were confirmed by the Changning Centers for Disease Control, Shanghai through western-blotting test.

100 samples detected by ELISA and Immuno-colloidal Golden Method were given negative results, 16 positive results existed in ECLIA group. There were1, 12, 3 positive cases in RF-IgM <18 U/ml, RF-IgM and RF-IgG>300 U/ml group(2.7%, 32.4%, 13.6%; P<0.01). In anti-CCP<25 RU/ml and>500 RU/ml groups there were 2 and 4 positive results(4.7%, 24.6%; P<0.01).

Different HIV screening test methods would give different results, according to operation requirement using second method to determine the HIV screening result. HIV False-positivity was associated with the titers of anti-CCP and RF in RA.(Chin J Lab Med, 2016, 39: 522-525)

Arthritis, rheumatoid; Human immunodeficiency virus; False positive reactions; Autoantibodies; Enzyme-linked immunosorbent assay