No abstract

ObjectivesIn our study group of Thai PLT apheresis donors, we assessed the prevalence of anti‐leucocyte antibodies.BackgroundAntibodies against human leucocyte antigens (anti‐HLA), neutrophil antigens (anti‐HNA), and major histocompatibility complex class I related chain A (anti‐MICA) in blood products can lead to transfusion‐related acute lung injury (TRALI). To reduce the risk of TRALI, some blood centres are implementing strategies based on screening platelet (PLT) apheresis donors for the presence of anti‐leucocyte antibodies.Methods/MaterialsBlood samples were collected from non‐transfused individuals, 340 males and 63 females (50 nulliparous and 13 parous). Anti‐HLA class I and II and anti‐MICA were analysed using the Luminex assay, and anti‐HNA‐3 was detected using the granulocyte agglutination test.ResultsAnti‐HLA was found in 14 of 403 subjects (3.5%). Ten subjects (2.5%) tested positive for HLA class I, 2 (0.5%) for HLA class II, and 2 (0.5%) for both HLA class I and HLA class II. Anti‐HLA class I or II were detected in 2 of 13 (15.4%) parous females and only anti‐HLA class I was found in 4 (8.0%) nulliparous females. Six of 327 subjects tested (1.8%), all males, were positive for anti‐MICA. Anti‐HNA‐3 was not found in any of the 403 individuals.ConclusionsScreening for anti‐HLA class I and II should be implemented for Thai PLT apheresis donors. Although immunisation against HNA and MICA seems to be a rare event in Thais, further work is necessary to decide whether our PLT apheresis donors should be screened for HNA and MICA antibodies.

Aim: Donor-recipient antigen mismatching for anti-human leucocyte antigen (HLA) and MICA is one of the risk factors for antibody induction leading to graft rejection.Our aim was to analyze the incidence and specificity of the different DSAs developing and to investigate the impact of HLA and MICA allele mismatches on antibody production in kidney transplant patients experiencing antibody-mediated rejection (AMR).Methods: We retrospectively reviewed 253 consecutive recipients of kidney transplant who were diagnosed as experiencing AMR.Results: Our results showed that around 27% of our patients were positive for DSAs over a median follow-up period of 24 months. Antibody to HLA-DQ7 was the most prevalent DSA detected. The allele mismatch number was significantly lower for DQ loci than -A and -B loci (DQ vs. A, p < .001; DQ vs. B, p = .002). Considering each HLA antigen, the incidence rate of DQ-DSA [41.9 (32.92-51.46; 95%CI)] was much higher than the rate observed for DSA directed to -A, -DR and -B loci. Half of the recipients in the DQ-DSA-only group, and the DQ-DSA together with non-DQ group, had MFI > 5000. Only one case developed de novo MICA-DSA (MICA002). Conclusion:Our study indicates that mismatching for HLA and MICA alleles leads to the development of HLA and MICA antibodies in some kidney transplant recipients.We have also demonstrated that DSA to the DQ locus is the most prevalent in kidney transplant patients with AMR. Thus, matching the DQ locus in kidney allocation algorithms may reduce post-transplant development of DSA.