摘要目的探讨寻常性银屑病患者表皮中HLA Ⅰ类分子重链A、B、C位点启动子区甲基化与疾病的关系。方法 甲基化特异性PCR技术检测46例寻常性银屑病患者皮损和非皮损表皮中的HLAⅠ类分子重链A、B、C位点启动子区域CpG岛的甲基化率，与28例正常人皮肤组织进行对照研究。PASI评分评价银屑病患者皮损的严重程度。结果 在银屑病患者皮损、非皮损和正常人皮肤组织中，重链A位点均未检测到发生甲基化，B位点的甲基化率分别是4.35％( 2/46)、4.35％( 2/46)和0，C位点的甲基化率分别是4.35％ (2/46)、21.74％( 10/46)和0。3组样本比较，C位点启动子区甲基化率非皮损明显高于皮损和正常人皮肤组织，但与病情严重程度无关；HLA Ⅰ类分子重链A和B位点差异均无统计学意义。结论 寻常性银屑病患者HLA Ⅰ类分子C位点启动子区甲基化异常。

abstractsObjective To investigate the correlation between the methylation status of HLA class Ⅰ genes (HLA-A, -B and -C) in psoriatic epidermis and disease severity in patients with psoriasis vulgaris. Methods DNA specimens were obtained from the lesional and nonlesional epidermis of 46 patients with psoriasis vulgaris and from the normal skin of 28 human controls. Methylation specific PCR (MSP) was conducted to detect the methylation status of CpG islands in the promoter region of HLA-A, -B and -C genes. The severity of psoriasis was evaluated by psoriasis area and severity index (PASI) scores. Results The percentage of promoter methylation of HLA-B and HLA-C genes was 4.35％ (2/46) and 21.74％ (10/46), respectively in nonlesional epidermis, 4.35％ (2/46) and 4.35％ (2/46), respectively in lesional epidermis from these patients. No methylation was observed for the promoter of HLA-A, -B or -C gene in the normal control epidermis or for that of HLA-A gene in the nonlesional or lesional epidermis from the patients. The frequency of HLA-C gene promoter methylation in the nonlesional epidermis was significantly higher than that in the lesional epidermis and control epidermis, but was uncorrelated to the disease severity. No significant difference was observed for the methylation frequency of HLA-A or -B gene promoter among the three groups of specimens. Conclusion Abnormal methylation of HLA-C gene promoter is observed in patients with psoriasis vulgaris.