Department of Nephrology, Perth Children's Hospital, Perth, WA, Australia.
School of Medicine, University of Western Australia, Perth, WA, Australia.
Front Immunol. 2022 Jun 20;13:844438. doi: 10.3389/fimmu.2022.844438. eCollection 2022.
High resolution human leukocyte antigen (HLA) typing is important in establishing eplet compatibility and the specificity of donor-specific anti-HLA antibodies (DSA). In deceased donor kidney transplantation, high resolution donor HLA typing may not be immediately available, leading to inaccuracies during the organ allocation process. We aimed to determine the concordance and agreement of HLA-Class I and II eplet mismatches calculated using population frequency based allelic haplotype association (linkage disequilibrium, LD) from sequence-specific oligonucleotide (SSO) and real-time polymerase chain reaction (rtPCR) donor HLA typing (available at time of donor kidney allocation) compared to high-resolution Next Generation Sequencing (NGS) donor typing. NGS high resolution HLA typing were available for all recipients prior to donor kidney allocation. A cohort of 94 deceased donor-recipient pairs from a single Western Australian center were included (77 individual donors typed, 55 local and 22 interstate). The number of class I (HLA-A+B+C) and class II (HLA-DRB1+DRB3/4/5+DQB1+DQA1+DPB1+DPA1) eplet mismatches were calculated using HLAMatchmaker, comparing LD- and NGS-HLA typing. The accuracy in assigning pre-transplant DSA was compared between methods. The concordance correlation coefficient (95%CI) for HLA-class I and II eplet mismatches were 0.994 (0.992 to 0.996) and 0.991 (0.986 to 0.993), respectively. The 95% limits of agreement for class I were -1.3 (-1.6 to -1.1) to 1.4 (1.2 to 1.7) and -4.8 (-5.7 to -3.9) to 5.0 (4.1 to 5.9) for Class II. Disagreement between the two methods were present for 11 and 37 of the Class I and II donor/recipient pairs. Of which, 5 had a difference of ≥5 class II eplet mismatches. There were 34 (36%) recipients with potential pre-transplant DSA, of which 8 (24% of recipients with DSA) had indeterminate and ultimately false positive DSA assigned by donor LD-typing. While the concordance between NGS- and LD-typing was high, the limits of agreement suggest meaningful differences between these two techniques. The inaccurate assignment of DSA from donor LD-typing may result in associated HLA being considered unacceptable mismatches, inappropriately precluding candidates' access to transplantation. Accurate imputation of two-field HLA alleles based on LD from SSO and rtPCR HLA typing remains a substantial challenge in clinical practice in-lieu of widely available, rapid, high-resolution methods.
高分辨率人类白细胞抗原 (HLA) 分型对于建立 eplet 相容性和供体特异性抗 HLA 抗体 (DSA) 的特异性非常重要。在已故供体肾移植中，高分辨率供体 HLA 分型可能无法立即获得，导致器官分配过程中的不准确。我们旨在确定使用基于群体频率的等位基因单倍型关联（连锁不平衡，LD）从序列特异性寡核苷酸 (SSO) 和实时聚合酶链反应 (rtPCR) 计算 HLA 类 I 和 II eplet 错配的一致性和一致性与高分辨率下一代测序 (NGS) 供体分型相比。在供体肾脏分配时，可获得供体 HLA 分型的实时 PCR (rtPCR)。NGS 高分辨率 HLA 分型可用于所有受体，在分配供体肾脏之前。纳入了来自西澳大利亚州单一中心的 94 对已故供体-受体队列（77 个个体供体分型，55 个本地和 22 个州际）。使用 HLAMatchmaker 计算了 HLA 类 I（HLA-A+B+C）和 II（HLA-DRB1+DRB3/4/5+DQB1+DQA1+DPB1+DPA1）eplet 错配的数量，比较了 LD-和 NGS-HLA 分型。比较了两种方法在分配移植前 DSA 中的准确性。HLA 类 I 和 II eplet 错配的一致性相关系数 (95%CI) 分别为 0.994 (0.992 至 0.996) 和 0.991 (0.986 至 0.993)。I 类的 95%一致性界限为 -1.3（-1.6 至 -1.1）至 1.4（1.2 至 1.7），-4.8（-5.7 至 -3.9）至 5.0（4.1 至 5.9））对于 II 类。两种方法之间存在 11 对和 37 对供体/受体的 I 类和 II 类错配。其中，5 对有≥5 个 II 类 eplet 错配的差异。有 34 名（36%）受者有潜在的移植前 DSA，其中 8 名（24%的有 DSA 的受者）通过供体 LD 分型分配了不确定和最终假阳性 DSA。虽然 NGS- 和 LD-分型之间的一致性很高，但一致性界限表明这两种技术之间存在有意义的差异。供体 LD 分型中 DSA 的不准确分配可能导致相关 HLA 被认为是不可接受的错配，不适当地排除候选者进行移植的机会。基于 SSO 和 rtPCR HLA 分型的 LD 对两个字段 HLA 等位基因的准确推断仍然是临床实践中的一个重大挑战，而不是广泛可用的快速高分辨率方法。
