Habiballah Saddiq B, Whangbo Jennifer S, Cardona Ivan D, Platt Craig D
Division of Immunology, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States of America.
Division of Hematology-Oncology, Boston Children's Hospital, Boston, MA, United States of America; Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, MA, United States of America.
Clin Immunol. 2022 May;238:109014. doi: 10.1016/j.clim.2022.109014. Epub 2022 Apr 18.
Potential etiologies of TBNK SCID include both hematopoietic defects and thymic aplasia. The management of patients with this phenotype, identified by newborn screen, may be unclear in the absence of a genetic diagnosis. We report an infant with lymphocyte flow cytometry consistent with TBNK SCID and reduced proliferative response to phytohemagglutinin. The patient had no genetic diagnosis after targeted panel and exome sequencing. The decision to trend laboratory values rather than move immediately to hematopoietic cell transplant was made given the absence of a genetic defect and the finding of a normal thymus on ultrasound. During the course of evaluation for transplant, the patient unexpectedly had normalization of T cell number and function. This case demonstrates a role for mediastinal ultrasound and the utility of trending laboratory values in patients with severe T cell lymphopenia but no genetic diagnosis, given the small but important possibility of spontaneous resolution.
TBNK重症联合免疫缺陷（SCID）的潜在病因包括造血缺陷和胸腺发育不全。对于通过新生儿筛查确定为此种表型的患者，在缺乏基因诊断的情况下，其治疗方案可能并不明确。我们报告了一名婴儿，其淋巴细胞流式细胞术结果与TBNK SCID一致，且对植物血凝素的增殖反应降低。经过靶向基因panel和外显子组测序后，该患者仍未得到基因诊断。鉴于不存在基因缺陷且超声检查发现胸腺正常，因此决定监测实验室指标变化趋势，而非立即进行造血细胞移植。在移植评估过程中，该患者的T细胞数量和功能意外恢复正常。鉴于存在自发缓解这种虽小但重要的可能性，本病例证明了纵隔超声的作用以及监测实验室指标变化趋势对于严重T细胞淋巴细胞减少但无基因诊断患者的实用性。
