Marinova Marina, Georgyeva Atanaska, Yordanova Viktoriya, Ivanov Nedelcho, Atanasova Valentina, Naumova Elissaveta, Kandilarova Snezhina Mihailova
Department of Clinical Immunology, Medical University Sofia, Bulgaria.
Clinic of Clinical Immunology with Stem Cell Bank, Alexandrovska University Hospital, Sofia, Bulgaria.
Cent Eur J Immunol. 2022;47(4):339-349. doi: 10.5114/ceji.2022.124396. Epub 2023 Jan 31.
Neonatal screening for inborn errors of immunity (IEI), based on quantification of T-cell-receptor- excision circles (TRECs) and kappa-deleting recombination-excision circles (KRECs) from dried blood spots (DBS), allows early diagnosis and improved outcomes for the affected children. Determination of TREC/KREC levels from prospectively collected newborns' Guthrie cards and from DBS samples of patients with confirmed IEI was done using a commercial kit. Retrospective assessment of flow cytometry evaluation of TREC/KREC correspondence with lymphocyte subpopulations and evaluation of the correlations between TREC and KREC with immune cells, based on the data from patients with suspected or confirmed immune disorders, were conducted. 2,228 Guthrie cards were tested, 1276 for TREC only and 952 for both TREC and KREC. Eight newborns (0.36%) were TREC positive and 10 (1.05%) had KREC below the cut-off. The re-testing rate was 1.88%. Retrospective analysis demonstrated that the TREC/KREC assay identifies 100% of severe combined immune deficiencies (SCID) cases when DBS were collected at birth. Correlation analysis showed moderate significant correlations between TREC and the absolute numbers of CD4 cells (r = 0.634, p < 0.01) and total T cells (r = 0.536, p < 0.01). The ability of KREC levels to predict abnormal absolute (AUC of 0.772) and relative (AUC 0.731) levels of B cells was demonstrated.
基于对干血斑（DBS）中T细胞受体切除环（TREC）和κ链缺失重组切除环（KREC）的定量分析，对先天性免疫缺陷（IEI）进行新生儿筛查，可实现对患病儿童的早期诊断并改善其预后。使用商用试剂盒对前瞻性收集的新生儿Guthrie卡片以及确诊IEI患者的DBS样本进行TREC/KREC水平测定。基于疑似或确诊免疫疾病患者的数据，对TREC/KREC与淋巴细胞亚群的对应关系进行流式细胞术评估的回顾性分析，以及对TREC和KREC与免疫细胞之间的相关性进行评估。共检测了2228张Guthrie卡片，其中仅检测TREC的有1276张，同时检测TREC和KREC的有952张。8名新生儿（0.36%）TREC呈阳性，10名（1.05%）KREC低于临界值。复检率为1.88%。回顾性分析表明，当出生时采集DBS时，TREC/KREC检测可识别出100%的重症联合免疫缺陷（SCID）病例。相关性分析显示，TREC与CD4细胞绝对数（r = 0.634，p < 0.01）和总T细胞绝对数（r = 0.536，p < 0.01）之间存在中度显著相关性。KREC水平预测B细胞绝对（曲线下面积为0.772）和相对（曲线下面积为0.731）水平异常的能力得到了证实。
