Luminex HLA antibody (AB) screening and identification has established itself as the preferred platform for determination of HLA-immunization in transplantation immunology and transfusion medicine. Due to the high sensitivity of the One Lambda (OL) kit we used previously, false-positive results were often obtained. For this reason, we performed comparative HLA-AB testing with the luminex-based assays from One Lambda and Immucor (IM).

Assays from OL LABScreen Mixed Class I & II and IM LIFECODES® LifeScreen XP were used according to the manufacturer's instructions. In case of different results, LABScreen Single Antigen (SA) HLA Class I/II from OL were applied as a reference. Assays were performed on Luminex LX200. We measured and compared HLA AB of 102 patients. 91 were included in this analysis. 2 were excluded due to bead failures, 2 due to missing SAs measurements and 7 due to undetermined results. Accuracy, sensitivity and specificity were calculated.

As can be seen in figure 1, OL and IM have an almost similar accuracy (87.91% vs. 85.71%), but OL has a higher sensitivity (92.31% vs. 53.85%) for class I HLA ABs. IM shows a better specificity (98.46% vs. 86.15%) for class I. For class II HLA ABs, IM shows more accuracy (94.51% vs. 84.62%) and specificity (98.72% vs. 87.18%). The sensitivity is equal for both assays (69.23%).

Based on the data, OL provides better results for class I and IM for class II HLA ABs. However, it should be noted that the assays use different antigen panels and therefore detect ABs differently. SAs assays from OL were used to check for discrepancy results, but the ongoing controversy over setting appropriate cut-offs for positivity must also be considered. In order to verify this more precisely, it is planned to check the discrepant results with the IM SA kits.

Hereby we declare that there is no conflict of interest.