非典型完全型DiGeorge综合征1例临床及免疫学特征分析

Clinical and immunological analysis of a Chinese boy with atypical complete Di George syndrome

目的探讨1例由22q11.2染色体微缺失导致非典型完全型Di George综合征的临床特征及免疫表型。方法收集2014年8月在重庆医科大学附属儿童医院就诊的1例非典型完全型Di George综合征患儿外周血标本,提取外周血单个核细胞(PBMC)及核酸,采用流式细胞术进行T、B细胞亚群检测,羧基荧光双乙酸钠琥珀酰亚胺酯(CFSE)标记法分析T细胞增殖功能,CDR3扫描谱型技术分析T细胞受体(TCR)多样性,定量PCR检测T细胞受体重排剪切环(TREC)含量。结果 T、B细胞亚群分析显示T细胞明显降低,初始T细胞<50个/mm3,总B细胞数量正常,记忆B细胞稍减低;CFSE增殖法提示患儿T细胞无增殖反应;TCR-Vβ亚家族表现为单克隆或寡克隆峰;定量PCR未检测到TREC含量。结论通过临床及免疫学分析,确诊1例非典型完全型Di George综合征患儿。Di George综合征临床与免疫学表型多变,其分型及临床诊断存在困难,常导致漏诊与延迟诊断,因此提高临床工作者对本病的认识对于早期诊断至关重要。

Di George syndrome（DGS） is a congenital malformation characterized by defects derived mainly from the third and fourth pharyngeal pouches. Patients with complete DGS presents the classic findings of DGS, but who later had rash, lymphadenopathy, and oligoclonal amplifications of T cells, is described as having atypical complete DGS. This study enrolled a male patient who was diagnosed of atypical complete DGS according to clinical manifestations and immunological analysis. Flow cytometry used for immunoscope evaluation revealed that he had low T cell number and without mitogen responsiveness. There were few recent thymic emigrants, as indicated absence of T-cell receptor rearrangement excision circles by Q-PCR and the low numbers of naive T cells（50/mm3）. Most of the 23 TCR-Vβ subfamilies showed monoclonal or oligoclonal peaks in this case, suggesting TCRVβ diversity was limited. Taken together, an atypical complete DGS patient is diagnosed. It is important for physicians to realize that patient with complete DGS remain profoundly immunodeficient after development of these atypical features.