主要组织相容性复合物在特发性炎性肌病中的表达及临床应用价值

目的 研究多发性肌炎(PM)和皮肌炎(DM)患者骨骼肌组织中的主要组织相容性复合物(MHC)的表达,探讨它们在特发性炎性肌病(IIM)发病机制中的作用及临床应用价值.方法 选取我院1986-2007年风湿免疫科收住的IIM患者骨骼肌组织标本45例(PM 19例,DM 26例),以性别、年龄相匹配的外伤患者骨骼肌标本30例作为对照.用免疫组织化学方法检测人类白细胞抗原(HIA)-A/B/C(即MHC-Ⅰ分子)和HLA-DR(即MHC-Ⅱ分子)在PM/DM患者及对照组肌组织中的表达.结果 HLA-A/B/C在18例PM、24例DM和3例对照组肌组织中有表达,阳性率分别为95%、92%和10%;HLA-DR在PM组、DM组和对照组肌组织中的阳性表达率分别为84%、81%和13%.HLA-A/B/C和HLA-DR在PM/DM患者肌组织中的表达量均较正常对照组明显升高(P均<0.05),但在PM组和DM组间差异无统计学意义(P均>0.05).根据组织病理学特点把PM/DM患者分为病变程度不同的3组,HLA-A/B/C和HLA-DR在PM/DM患者肌组织中的表达量与肌纤维变性、坏死、炎症浸润的程度和各项临床及实验室指标无明显关联(P均>0.05).结论 MHC-Ⅰ和Ⅱ类分子在PM/DM患者肌肉组织中表达增高,在无明显炎症浸润和肌纤维坏死的患者中也可见到这种表达的上调,检测肌组织中MHC-Ⅰ和Ⅱ类分子的表达可用于PM/DM的诊断.

The expression of major histocompatibility complex in idiopathic inflammatory myopathies and its clinical application

Objective To study the expression of major histocompatibility complex(MHC)on muscle biopsy specimens of idiopathic inflammatory myopathies(IIM),and assess diagnostic value of MHC in IIM. Methods Forty-five patients with IIM(19 polymyositis and 26 dermatomyositis)were selected for this study.Thirty healthy subjects were included as controls.Immunohistochemical staining was applied to identify the expression of HLA-A/B/C and HLA-DR on muscle biopsy-specimens in polymyositis (PM)/deFmatomyosiris (DM) patients and healthy controls.Results HIA-A/B/C antigens were expressed in muscle fibers in 18 out of 19 PM patients(95%),24 out of 26 DM patients(92%) and 3 out 0f 30 healthy controls(10%) respectively.The positive expression rate of HLA-DR in PM,DM patients and healthy controls were 84%, 81%,13%,respectively.The expressions of HLA-A/B/C and HLA-DR were significantly increased in PM and DM patients than those in healthy controls(both P<0.05),but no significant differences were found between PM and DM groups(both P>0.05).No significant correlations were demonstrated between the over-expression of HLA-A/B/C or HLA-DR and the extent of inflammatory infiltrations,muscle damage or clinical features in PM/DM groups (all P values>0.05).Conclusion MHC-Ⅰ and MHC-Ⅱover-expression in muscle fibers are the early events in PM and DM,and may occur in the absence of lymphocyte infihration and muscle damage.Immunostaining for MHC-Ⅰ and MHC-Ⅱcan be used as a routine test in the diagnosis of PM and DM.