Clinical Relevance of Anti-HLA Donor-Specific Antibodies Detected by Luminex Assay in the Development of Rejection After Renal Transplantation

Background. The role of anti-human leukocyte antigen (HLA) donor-specific antibodies (DSA) detected by Luminex in the development of rejection is not fully understood. Methods. A study including 369 patients who received transplants from deceased donors with a negative complement-dependent cytotoxicity crossmatch (XM) was performed. From the total of patients, 151 underwent a renal biopsy because of renal dysfunction, whereas the 218 remaining showed a stable renal function, and no rejection was assumed. Diagnosis and type of rejection was based in biopsy data. Results. Patients with a positive virtual XMs showed more rejection episodes of any types when comparing with patients with negative virtual XMs (P<0.0001). Nevertheless, there were no significant differences between patients without anti-HLA antibodies and patients with anti-HLA no DSA. Allograft impairment was caused by a rejection episode in 84% (32/38) of patients with anti-HLA-DSA but only in 30% (34/113) of patients without antiYHLA-DSA. Regarding the type of rejection detected in the biopsy, all the patients with de novo (after transplantation) antiYHLA-DSA were diagnosed as antibody-mediated rejection (AMR) or AMR+T-cell-mediated rejection, whereas most of the patients without antiYHLA-DSA (68%) were diagnosed with T-cell-mediated rejection, and patients with preexistent anti-HLA-DSA showed a more homogeneous distribution of the different types of rejection. Conclusions. According to our results, patients with preformed or de novo antiYHLA-DSA showed the highest likelihood to suffer rejection episodes. Transplantation with preformed antiYHLA-DSA should be avoided, and an early detection of de novo HLA antibodies is important to treat patients before damage occurs in the graft.