Evaluation of a new serological test for syphilis based on chemiluminescence assay in a tertiary care hospital

CONTEXT: Syphilis is a transfusion transmissible infections and it is mandatory to do serological test for syphilis (STS) on all donor blood samples. STS is usually based on detection of antibodies against the cardiolipin-lecithin antigen or against the Treponema-specific antigen. STS with good sensitivity and specificity helps enhance blood safety and consolidation of STS along with other transfusion transmittable infections such as human immunodeficiency virus, hepatitis-C virus, and hepatitis-B virus helps in reducing the errors and enhances efficiency. AIMS: This study was designed to evaluate the performance of newly introduced VITROS(®) syphilis Treponema pallidum agglutination (TPA) assay based on enhanced chemiluminescence principle for its analytical performance for use as a STS on donor blood samples at a tertiary care health center in National Capital Region, India. MATERIALS AND METHODS: A total of 108 random blood units collected from the donors (both voluntary and replacement donors) and 28 known syphilis sero-reactive samples stored at −20°C, were used to evaluate the performance of VITROS(®) syphilis TPA assay based on enhanced chemiluminescence assay on VITROS(®) ECiQ immunodiagnostics system along with its analytical performance in terms of its sensitivity, precision, cross-reactivity and interference studies. RESULTS: VITROS(®) syphilis TPA showed 100% sensitivity and specificity with precision (20 days study) of <10% co-efficient of variation. There was no cross-reactivity with other viral and auto-immune antibodies. No interference was observed from endogenous interfering substances like free hemoglobin or fats. CONCLUSIONS: Performance of the VITROS(®) syphilis TPA assay meets the requirements for its use as STS in blood bank, thus allowing consolidation with other transfusion transmittable infections screening assay on chemiluminescence platform, which is highly valuable for optimizing workflow and efficiency.