Comparison of Two Different Serological Viral Marker Testing Assays for Screening of Apheresis Donors: Which Assay Provides Optimum Safety for Transfusion?

While whole blood testing has evolved over the years, viral marker testing for plateletpheresis donors is still performed by Rapid Diagnostic Tests (RDT). Aim of this study was to compare diagnostic accuracy of RDT and Chemiluminescence Immunoassay (CLIA) in serological testing for HBsAg, anti-HCV and anti-HIV antibodies. A prospective, analytical study was conducted in the department of Transfusion Medicine at a tertiary healthcare center in India between September 2016 and August 2018. Samples were simultaneously tested by CLIA, RDT and a confirmatory test. Sensitivity, specificity, negative and positive predictive values and mean time taken to report results were calculated. A total of 102 (1.48%) of the 6883 samples were found to be reactive by either or both the assays. A total of 74 (1.08%) samples were HBsAg reactive, 23 (0.33%) were reactive for anti-HCV antibodies and 5 (0.07%) were reactive for anti-HIV I and II antibodies. A combined sero-prevalence of 1.05% (72) was observed; 0.78% (54) for HBsAg, 0.26% (18) for anti-HCV antibodies and none for anti-HIV I and II antibodies. Four (3.85%) reactive samples were missed by RDT and therefore sensitivity of RDT was quite less as compared to CLIA. RDT and CLIA both were found to have a statistically significant shorter turnaround time than confirmatory tests. There is increasing need to develop a safe donor screening strategy for plateletpheresis. CLIA offers an excellent alterative to RDT for viral marker testing in terms of sensitivity.