Department of Pediatric Immunology and Leukocyte Biology, National Institute of Immunohematology (ICMR), Mumbai, Maharashtra, India.
Division of Immunology, Bai Jerbai Wadia Children's Hospital, Mumbai, Maharashtra, India.
Indian J Pediatr. 2019 Jul;86(7):584-589. doi: 10.1007/s12098-019-02904-9. Epub 2019 Mar 16.
Severe combined immunodeficiency (SCID) represents one of the most severe forms of Primary immunodeficiency (PID) disorders, characterized by T cell lymphopenia (TCL) and lack of cellular and humoral immune responses. However, not all patients with low T cell lymphocyte counts may have an abnormal T cell immunity and the observed TCL may be a temporary suppression resulting from transient lymphopenia secondary to severe infections. In such cases, it is necessary to estimate the severity of the observed TCL by assessing thymic capabilities.
In this study, patients clinically suspected of SCID were evaluated for lymphocyte subsets analysis, naïve T cells and T cell receptor excision circles (TREC).
Patients with transient lymphopenia had detectable TREC levels and normal naïve T cells subsets. Normalization of absolute lymphocyte counts, and T cells was seen in the patients after a short duration.
The authors highlight the importance of detailed immunological investigations in an infant with severe infections and lymphopenia before labeling the infant as SCID.
严重联合免疫缺陷（SCID）是原发性免疫缺陷（PID）疾病中最严重的一种，其特征是 T 细胞淋巴细胞减少症（TCL）和缺乏细胞和体液免疫反应。然而，并非所有 T 细胞淋巴细胞计数低的患者都可能存在异常的 T 细胞免疫，观察到的 TCL 可能是由于严重感染继发的短暂淋巴细胞减少导致的暂时抑制。在这种情况下，有必要通过评估胸腺功能来估计观察到的 TCL 的严重程度。
本研究对临床疑似 SCID 的患者进行了淋巴细胞亚群分析、幼稚 T 细胞和 T 细胞受体切除环（TREC）的评估。
一过性淋巴细胞减少症患者的 TREC 水平可检测到，幼稚 T 细胞亚群正常。在短暂的时间后，患者的绝对淋巴细胞计数和 T 细胞计数恢复正常。
作者强调了在严重感染和淋巴细胞减少的婴儿被标记为 SCID 之前，对其进行详细免疫调查的重要性。
