Associate Professor, Gold Standard Laboratory Consulting Group, LLC, and Department of Pathology, University of Virginia, Charlottesville, VA.
Medical Technologist II, Immunohematology Reference Laboratory, ITxM Diagnostics, Richmond, VA.
Immunohematology. 2020 Dec;36(4):123-128.
In recent years, polymerase chain reaction-based genotyping platforms, which provide a predicted phenotype, have increased in both patient and high-throughput donor testing, especially in situations where serologic methods or reagents are limited. This study looks at the concordance rate between two platforms commercially available in the United States when used for testing samples from patients with sickle cell disease (SCD), a group particularly vulnerable to alloimmunization. DNA extracted from samples from 138 patients with SCD was tested by human erythrocyte antigen (HEA) BeadChip (Immucor, Norcross, GA) and by ID CORE XT (Progenika-Grifols, Barcelona, Spain). Predicted phenotype results were compared, and a concordance rate was calculated. Discrepancies were resolved by Sanger sequencing. All testing was done under an institutional review board-approved protocol. A concordance rate of 99.9 percent was obtained. Sanger sequencing was performed on four samples with discrepancies in the Rh blood group system. Three samples had a similar allelic variant detected by ID CORE XT. Two of the three discrepant samples were correctly identified as V+w, VS- by ID CORE XT but not by HEA BeadChip. The third sample, predicted to have a phenotype of V+, VS+ by sequencing, was called correctly by HEA BeadChip but not by ID CORE XT, which had predicted V+w, VS-. The fourth discrepancy was identified in a sample that ID CORE XT accurately identified as RHCE*ce[712G] and predicted a partial c phenotype. This result was confirmed by Sanger sequencing, whereas HEA BeadChip found no variants and predicted a c+ phenotype. The high concordance rate of the two methods, along with the known limitations of serology, warrant further discussion regarding the practice of serologic confirmation of extended phenotypes. Clinical significance of the identified discrepancies remains to be determined.
近年来，聚合酶链反应（PCR）基因分型平台在患者和高通量供者检测中的应用越来越多，尤其是在血清学方法或试剂有限的情况下。本研究旨在探讨两种美国市售平台在用于检测镰状细胞病（SCD）患者样本时的一致性，SCD 患者群体特别容易发生同种免疫。从 138 例 SCD 患者的样本中提取 DNA，分别用人类红细胞抗原（HEA）BeadChip（Immucor，Norcross，GA）和 ID CORE XT（Progenika-Grifols，巴塞罗那，西班牙）进行检测。比较预测表型结果，并计算一致性率。通过 Sanger 测序解决差异。所有检测均在机构审查委员会批准的方案下进行。获得了 99.9%的一致性率。在 Rh 血型系统存在差异的 4 个样本中进行了 Sanger 测序。ID CORE XT 检测到三个样本具有相似的等位基因变异。三个差异样本中的两个被正确识别为 ID CORE XT 而非 HEA BeadChip 的 V+w，VS-。第三个样本，经测序预测表型为 V+，VS+，HEA BeadChip 正确识别，但 ID CORE XT 预测为 V+w，VS-。第四个差异发生在一个 ID CORE XT 准确识别为 RHCE*ce[712G]并预测部分 c 表型的样本中。这一结果通过 Sanger 测序得到证实，而 HEA BeadChip 未发现变异，预测为 c+表型。两种方法的高一致性率，加上血清学的已知局限性，进一步讨论了血清学确认扩展表型的做法是合理的。所鉴定差异的临床意义仍有待确定。
