难治性病毒感染和原发噬血细胞性淋巴组织细胞增多症相关基因突变研究

The study of gene mutations in unknown refractory viral infection and primary hemophagocytic lymphohistocytosis

目的研究难治性病毒感染或噬血细胞性淋巴组织细胞增多症（HLH）中免疫基因突变的发生率、类型及其临床特征。方法采用基因测序方法检测难治性病毒感染或HLH患者是否有原发性HLH相关的PRFl、UNCl3D、STXl1、STXBP2、SH2D1A和XIAP基因突变，并追踪其临床特点及转归。结果共25例难治性病毒感染性疾病或HLH患者接受了基因突变筛查，其中13例检测到上述基因突变：PRFl突变6例，UNCl3D突变3例，STXll、STXBP2、SH2D1A、XIAP突变各1例；其中6例起病表现为病毒相关性HLH，1例为原因不明HLH，4例为慢性活动性EB病毒（EBV）感染（CAEBV），2例为EBV相关性淋巴瘤。12例未检测出基因突变的患者中，4例为EBV相关HLH，其中1例发展为外周T细胞淋巴瘤，另8例为CAEBV。结论原发性HLH相关免疫基因突变是难治性病毒感染或HLH的重要原因，大部分表现为HLH，部分患者以CAEBV或EBV相关淋巴瘤起病。基因检测是明确此类疾病诊断的有力证据。

Objective To study the type and corresponding clinical characteristics of primary hemophagocytic lymphohistocytosis （HLH） associated immune gene mutations in the refractory virus infection or HLH of unknown causes. Methods From December 2009 to July 2010, the patients with refractory virus infection or HLH of unknown causes were screened for the primary HLH associated immune genes mutations by DNA sequence analysis, including PRF1, UNC13D, STXll, STXBP2, SH2D1A and XIAP. The clinical characteristics and outcomes were followed up. Results Totally 25 patients with refractory virus infection or HLH of unknown causes were investigated for the 6 genes and 13 cases were found carrying gene mutations, composing of 6 of PRF1 mutation, 3 of UNC13D, and each one of STX11, XIAP, SH2D1A and STXBP2, respectively. Among the 13 cases with gene mutations, 5 suffered from Epstein-Barr virus associated HLH（EBV-HLH） , 1 human herpes virus 7 associated HLH （HHV7-HLH） , 1 HLH without causes, 4 chronic activated EB virus infection（CAEBV） with 1 progressing to Hodgkin＇s lymphoma carrying abnormal chromosome of t （ 15 ; 17 ） （ q22 ; q25 ） and hyperdiploid, 2 EBV associated lymphoma. Among the other 12 patients without gene mutation, 4 suffered from EBV-HLH with 1 progressing to peripheral T lymphoma, 8 suffered from CAEBV. Conclusions Primary HLH associated immune gene mutations are critical causes of refractory virus infection of unknown causes, most patients manifest as HLH, some cases appear in CAEBV and EBV associated lymphoma. DNA sequence analysis is helpful to early diagnosis and correct decision-making for treatment.