Luminex technology for anti-HLA antibody screening : evaluation of performance and of impact on laboratory routine

The recent introduction of new technologies such as Luminex has provided alternative methods to the Complement Dependent Cytotoxicity (CDC) test for HLA specific antibody detection. In this study we compared the results obtained with CDC to those obtained using a Luminex method with the aim of evaluating the impact of this new technology on antibody screening policies in our transplant setting. A total of 1,421 sera, acquired from patients on the waiting list for a kidney transplant or following transplantation, were tested by both methodologies. CDC was performed using a whole lymphocyte population comprising a panel of 52 cells. The percentage panel reactive antibodies (PRA) and antibody specificity were evaluated using Lambda Scan Analysis software. For the Luminex method sera screening and identification of antibody specificity were carried out using the LABScreen Mixed and LABScreen PRA respectively. The overall concordance between the results obtained using the CDC and the Luminex methods was 85%. HLA antibody specificity was confirmed in 96% of the sera which tested positive using the Luminex system and serum positivity corresponded with a previous sensitisation event in these individuals. Using the Luminex method 18% of patients on the waiting list were considered and managed as sensitised as compared to 7% when testing with CDC alone. The Luminex method was able to detect a number of antibody specificities significantly more frequently than the CDC method and in addition the CDC method failed to detect some of the antibody specificities detected by the Luminex system. Based on this comparison study we have incorporated the Luminex methodology into our screening strategy.