Abstract：
BACKGROUND: Recipient\'s high resolution HLA typing is required in allogeneic hematopoietic cell transplantation from unrelated donors, as well as for haploidentical family donors. For these purposes, Next-Generation Sequencing (NGS) methods are the gold standard.
METHODS: We present a case of a patient with an incorrect HLA typing result caused by the population of circulating lymphoma cells. The first HLA examination was performed from peripheral blood (PB) using NGS in the active phase of diffuse large B-cell lymphoma with bone marrow involvement.
RESULTS: Because of rare and inconclusive results, confirmed twice for the A* locus (A*02:32N), real-time polymerase chain reaction (RT-PCR)was performed. With RT-PCR method, we obtained more expected results according to the population allele frequency: in HLA-A locus (A*02:01) but also in DQB1 (DQB1*03:01, not as in NGS - DQB1*03:10). For the final verification, we used swab material and we obtained unambiguous NGS result with expected, frequent HLA-A*02:01 and DQB1*03:01 alleles corresponding to the RT-PCR result from PB.
CONCLUSIONS: To conclude, we suspect that the discrepancies between NGS and RT-PCR results were caused by the presence of a significant amount of circulating lymphoma cells in the peripheral blood sample. Lymphomagenic mutations may involve the histocompatibility antigen coding region and affect HLA expressed on malignant cells. This finding may be relevant for the selection of test material in primary and confirmatory HLA testing in patients with active hematological malignancies because of the strong impact of incorrect HLA typing on the procedure of a donor selection.
METHODS: We present a case of a patient with an incorrect HLA typing result caused by the population of circulating lymphoma cells. The first HLA examination was performed from peripheral blood (PB) using NGS in the active phase of diffuse large B-cell lymphoma with bone marrow involvement.
RESULTS: Because of rare and inconclusive results, confirmed twice for the A* locus (A*02:32N), real-time polymerase chain reaction (RT-PCR)was performed. With RT-PCR method, we obtained more expected results according to the population allele frequency: in HLA-A locus (A*02:01) but also in DQB1 (DQB1*03:01, not as in NGS - DQB1*03:10). For the final verification, we used swab material and we obtained unambiguous NGS result with expected, frequent HLA-A*02:01 and DQB1*03:01 alleles corresponding to the RT-PCR result from PB.
CONCLUSIONS: To conclude, we suspect that the discrepancies between NGS and RT-PCR results were caused by the presence of a significant amount of circulating lymphoma cells in the peripheral blood sample. Lymphomagenic mutations may involve the histocompatibility antigen coding region and affect HLA expressed on malignant cells. This finding may be relevant for the selection of test material in primary and confirmatory HLA testing in patients with active hematological malignancies because of the strong impact of incorrect HLA typing on the procedure of a donor selection.
摘要：
背景：在来自无关供体的异基因造血细胞移植中，需要受者的高分辨率HLA分型，以及单倍体家庭捐赠者。出于这些目的,下一代测序(NGS)方法是黄金标准。
方法：我们介绍了一例由于循环淋巴瘤细胞群引起的HLA分型结果不正确的患者。在弥漫性大B细胞淋巴瘤的活跃期，使用NGS从外周血（PB）进行了首次HLA检查。
结果：由于罕见且不确定的结果，确认了两次A*基因座（A*02：32N），进行实时聚合酶链反应(RT-PCR)。用RT-PCR法,根据群体等位基因频率，我们获得了更多的预期结果:在HLA-A基因座(A*02:01)，也在DQB1(DQB1*03:01，不像NGS-DQB1*03:10)。为了最后的验证，我们使用拭子材料，我们获得了明确的NGS结果，对应于来自PB的RT-PCR结果的常见HLA-A*02:01和DQB1*03:01等位基因。
结论：总而言之，我们怀疑NGS和RT-PCR结果之间的差异是由于外周血样本中存在大量循环淋巴瘤细胞引起的.淋巴瘤突变可能涉及组织相容性抗原编码区，并影响恶性细胞上表达的HLA。由于不正确的HLA分型对供体选择程序的强烈影响，因此该发现可能与在活动性血液系统恶性肿瘤患者的原发性和确证性HLA测试中选择测试材料有关。
方法：我们介绍了一例由于循环淋巴瘤细胞群引起的HLA分型结果不正确的患者。在弥漫性大B细胞淋巴瘤的活跃期，使用NGS从外周血（PB）进行了首次HLA检查。
结果：由于罕见且不确定的结果，确认了两次A*基因座（A*02：32N），进行实时聚合酶链反应(RT-PCR)。用RT-PCR法,根据群体等位基因频率，我们获得了更多的预期结果:在HLA-A基因座(A*02:01)，也在DQB1(DQB1*03:01，不像NGS-DQB1*03:10)。为了最后的验证，我们使用拭子材料，我们获得了明确的NGS结果，对应于来自PB的RT-PCR结果的常见HLA-A*02:01和DQB1*03:01等位基因。
结论：总而言之，我们怀疑NGS和RT-PCR结果之间的差异是由于外周血样本中存在大量循环淋巴瘤细胞引起的.淋巴瘤突变可能涉及组织相容性抗原编码区，并影响恶性细胞上表达的HLA。由于不正确的HLA分型对供体选择程序的强烈影响，因此该发现可能与在活动性血液系统恶性肿瘤患者的原发性和确证性HLA测试中选择测试材料有关。
