自身免疫性肝炎患者可溶性肝抗原特异性T淋巴细胞反应特点及其临床意义

Characteristics of SLA specific T cell response and its clinical significance in autoimmune hepatitis patients

目的 分析评价AIH患者SLA特异性T淋巴细胞反应特点.方法 用化学法人工合成SLA序列多肽段作为刺激肽,刺激31例AIH患者（SLA/LP抗体阳性10例,SLA/LP抗体阴性21例）、30例PBC患者、29例病毒性肝炎患者和30名健康人中PBMC,使其分泌干扰素γ（IFN-γ）,并采用ELISpot方法观察各组SLA肽特异性T淋巴细胞反应特点.结果 31例MH患者中18例患者PBMC对SLA肽库刺激可诱导分泌IFN-γ,其阳性率58.06%（18/31）,PBC、病毒性肝炎患者、健康人阳性率分别为3.33%（1/30）、3.45%（1/29）、0.00%（0/30）,AIH患者PBMC受SLA肽库刺激分泌INF-γ阳性率明显高于PBC、病毒性肝病患者及健康人（x2值分别为21.295、20.655、15.988,P均＜0.01）.18例AIH患者反应单肽位于SLA中8个抗原簇,包括aa1～44、aa57～132、aa129～180、aa177～196、aa 193～244、aa241～268、aa281～308、aa321～428;平均识别SLA序列单肽宽度为6（2～17）条,显示多克隆性.18例呈阳性反应的AIH患者中14例患者在采集PBMC同时进行肝功能检测,该14例患者识别SLA序列单肽的反应宽度与谷草转氨酶（AST）对数值呈正相关（r=0.539,P＜0.05）.结论 SLA肽库可诱导AIH患者外周血PBMC分泌IFN-γ,其反应呈多克隆性,反应宽度间接反映患者肝脏炎症活动程度.

Objective To analyze the feature of SLA specific T cell response in AIH. Methods Thirtyone cases of AIH were enrolled by investigating T-cell reactivity against chemically synthesized peptides spanning the full SLA protein using ELISpot. The 31 cases of AIH included 10 anti-SLA/LP positive cases and 21 negative cases. The control groups included 30 PBC patients, 29 chronic viral hepatitis patients and 30 healthy cases. The secretion of IFN-γ after PBMC stimulated by SLA peptides was observed. Results Eighteen of 31 cases with AIH [56. 08 % （ 18/31 ） ] showed the positive response to SLA peptide pools, and only 1 of 30 patients with primary biliary cirrhosis （3.34%） and 1 of 29 patients with virus hepatitis （ 3.44% ）, could be elicited responses by SLA peptide pools. There wasn＇t positive response in healthy eases. The response frequency to SLA peptides in AIH group was significantly higher than those in PBC cases, chronic viral hepatitis cases and healthy cases （X2 = 21. 295, 20. 655, 15.988, P 〈 0. 01 ）. Amongst 18 AIH patients with positive responds to SLA pool, 8 antigen clusters including aa 1-44, aa 57-132, an 129-180,aa 177-196, aa 193-244, aa 241-268, aa 281-308 and aa 321-428 were highlighted. The mean number of recognized peptides was 6 （2-17）, indicating the polyclonal feature. Fourteen of 18 AIH patients with positive response to SLA peptides were subjected to live function test simultaneously when PBMC were collected. There was significant correlation between the breadth of recognized poptides and AST （ logarithm, r = 0. 539, P = 0. 045）. Conclusions SLA peptides can induce PBMC in peripheral blood of AIH patients to secrete IFN-γ and it is polyclonal response. The breadth of recognized peptides may reflect the degree of liver inflammation.