The HLAMatchmaker (HLAMM) evaluates the compatibility between donor and recipient through comparisons within and between loci, and determines which epitopes in HLA mismatched are different or shared between them. The concept of epitope matching should be considered when classifying a given HLA antibody (ab) as DSA or NDSA. Distinguishing between them is critical when considering clinical relevance of HLA ab. Luminex single-antigen beads (LSA) allow a more precise definition of ab specificity. A negative CM and DSA detected in LSA isn't a contraindication to transplant, but the DSA have a negative impact on kidney graft survival. The LSA can be used to monitor patients that DSA persist after transplantation. This study proposes a different approach to the analysis of LSA results to provide a tool to assess patient at risk of graft failure. The idea is to compare the patterns behavior of MFI average values for DSA and NDSA. We studied 17 renal transplant patients with CDC-AHG negative CM and DSA detect in pre-tx sera. Each patient had 3 pre-tx sera and samples for 3, 5, 10, 15, 30 days and 3, 6, 12 and 18 months post-transplant. Abs characterized by LSA was analyzed by HLAMM to determine immunogenic epitopes. Results were put into a graph considering MFI values and sample timeline to obtain a reaction pattern. Clinical outcomes were taken in consideration in reaction pattern analysis. To obtain results from observation of pattern behavior, we established that the pattern from reactions for NDSA MFI values should be considered the standard profile. If the DSA pattern behaviors don’t match the standard profile and we aren’t able to overlap both curves, the risk of AMR is real. In 83% of the cases with good outcome, pattern variation of NDSA and DSA had matching oscillations. In the group with rejection episodes, 72% of the patients NDSA and DSA pattern variations could not be matched, showing different behavior. While MFI and cut off values are still a matter of debate in LSA analyses, our results suggest that observation of NDSA versus DSA pattern behavior could be successfully used to assess risk of graft failure by AMR.

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