中国南方汉族人群中抗癫痫药物导致的皮肤型不良反应与HLA-A*2402的相关性及机制研究

Aromatic antiepileptic drugs (AAEDs), including carbamazepine (CBZ), oxcarbazepine (OXC), lamotrigine (LTG), phenytoin (PHT) and phenobarbital (PB), are widely prescribed in clinics and effective in seizures control. However, they are also among the most common causes of cutaneous adverse drug reactions (cADRs) with relatively high incidences in up to at least 16% of patients. The cADRs induced by AAEDs (AAEDs-cADRs) vary from mild maculopapular eruption (MPE), with increasing severity to hypersensitivity syndrome (HSS), Stevens-Johnson syndrome (SJS), and toxic epidermal necrolysis (TEN). Among the AAEDs-cADRs, SJS and TEN are two of most serious and life-threatening cADRs with a mortality rate up to 40%. Recently, pharmacogenetics studies have shown that there is a possible association between AEDs-cADRs and HLA alleles, based on a strong association between HLA-B*1502 and CBZ-SJS/TEN in Han Chinese population and Southeast Asian populations. What's more, a newly study demostrated that screening patients for the HLA-B*1502 allele before the initiation of CBZ treatment and withholding CBZ from B*1502-positive patients can reduce the incidence of CBZ-induced SJS/TEN in Han Chinese. However, it does not mean that every case with HLA-B*1502 negative is safe for CBZ-SJS/TEN, neither each kind of AAEDs-cADRs is associated with HLA-B*1502. Cases with CBZ-SJS/TEN negative for HLA-B*1502 were reported in Southeast Asia and in Han Chinese population. Instead of HLA-B*1502, HLA-A*2402 was present in cases with CBZ-SJS/TEN negative for B*1502, and was significantly more frequent than that of CBZ-tolerant controls or the general southern Han population in our pilot study. We also noticed that HLA-A*2402 may has a same association with LTG-SJS/TEN in our preliminary experiment. It supposed that HLA-A*2402 is a common risk allele for the AAEDs-SJS/TEN. Therefore, we further investigate the relationship between HLA-A*2402 and AEDs-SJS/TEN, and HSS, and MPE in large samples by high-resolution HLA genotyping in Southern Han Chinese. And, we employed molecular, cellular immunological methods to explore the possible role of the receptors of cytotoxic T cells from AAEDs-SJS/TEN patients who are positive for HLA-A*2402. This study is expected to disclose the relationships between AAEDs-cADRs and HLA-A alleles, which may be helpful in understanding the function of HLA complex as well as the pathogenesis of AAEDs-cADRs. Meanwhile, it can provide a benefit in reducing the incidence of AAEDs-cADRs in Han Chinese by avoiding prescribing annoying drugs to subjects at genetic risks.

芳香环结构的抗癫痫药物（AEDs）能有效控制癫痫发作，但部分患者服用后会发生皮肤型药物不良反应（cADRs），临床表现从轻型的MPE到危及生命的重型皮疹SJS/TEN，致死率可高达40%。多项研究显示在汉族人群中HLA-B*1502与CBZ-SJS/TEN强相关。但并不是所有芳香族AEDs-SJS/TEN均与B*1502有关。我们前期即在B*1502阴性的CBZ-SJS/TEN患者中筛查出HLA-A*2402基因，发现A*2402与CBZ-SJS/TEN有关，进一步的研究发现A*2402亦可能与LTG-SJS/TEN有关，提示A*2402可能是AEDs-SJS/TEN共同的遗传危险因素。因此，本研究将进一步扩大样本量，分析南方汉族人群中HLA-A*2402与AEDs-cADRs的相关性，研究A*2402在cADRs发生中的可能机制，以提供诊断及治疗的靶分子，降低或避免cADRs的发病风险。

项目背景：芳香环结构的抗癫痫药物（AEDs）有效控制癫痫发作，但部分患者服用后会发生皮肤型药物不良反应（cADRs），临床表现从轻型的MPE到危及生命的重型皮疹SJS/TEN，致死率可高达40%。多项研究显示在汉族人群中HLA-B*1502与CBZ导致的SJS/TEN强相关，我们前期在HLA-B*1502阴性的CBZ-SJS/TEN患者中筛查出HLA-A*2402基因，发现HLA-A*2402与CBZ-SJS/TEN有关，与LTG导致的SJS/TEN可能相关，推测HLA-A*2402可能是AEDs-SJS/TEN共同的遗传危险因素。因此，本研究将进一步扩大样本量，分析南方汉族人群中HLA-A*2402与AEDs导致的cADRs的相关性，并研究HLA*2402在cADRs发生中的可能机制。.主要研究内容：（①采用病例-对照研究，多中心采集2006-2015年中国南方地区汉族人群cADRs与耐受对照，应用PCR直接测序法，检测每个样本的HLA基因型，采用χ2 检验和logistic回归分析HLA基因与AEDs导致cADRs的相关性；②克隆HLA-A*24:02、 B*15:02基因，慢病毒包装后转入无HLA-Ⅰ型基因表达的Hmy2.CIR细胞系，通过质谱检测加入卡马西平前后HLA-A*2402细胞表面结合肽的变化，探查HLA-A*2402结合肽在SJS/TEN的作用。.关键数据：（1）共采集中国南方地区汉族人群的92例SJS及322耐受对照，发现HLA-A*2402为AEDs-SJS的通用危险因子，成显著正相关（P = 1.02  10-5）；证实HLA-B*1502与CBZ-SJS成显著正相关（P = 5.63 10-15）。使用AEDs之前，筛查HLA-A*2402和HLA-B*1502,能将SJS的风险从35.8/10000降低为13/10000。（2）卡马西平添加后， HLA-A*2402新增与免疫反应相关Coronin蛋白,HLA-A*2402可能通过与致敏反应正相关的冠蛋白Coronin，参与AEDs导致的ADRs。.科学意义: ①HLA-A*2402为AEDs-SJS的通用遗传标记，建议患者在使用AEDs之前进行HLA-A*2402及HLA-B*1502的检测，降低cARDs发病风险；②提出HLA-A*2402参与AEDs-ADRs可能是通过冠蛋白。