Steinsson K, Jónsdóttir S, Arason G J, Kristjánsdóttir H, Fossdal R, Skaftadóttir I, Arnason A
Department of Internal Medicine, Landspítalinn, National University Hospital, Reykjavik, Iceland.
Ann Rheum Dis. 1998 Aug;57(8):503-5. doi: 10.1136/ard.57.8.503.
To perform an exploratory analysis of the relative contribution of single MHC genes to the pathogenesis of systemic lupus erythematosus (SLE) in a homogenous white population.
MHC class II alleles and C4 allotypes were determined in 64 SLE patients and in ethnically matched controls. HLA-DR and DQ typing was performed by polymerase chain reaction amplification with sequence specific primers. C4 allotypes were determined by agarose gel electrophoresis.
The frequency of C4AQ0 was significantly higher in patients than in controls (46.9% v 25.3%, p = 0.002). HLA-DRB1, DQA1, and DQB1 alleles in the whole group of SLE patients were not significantly different from those of controls. On the other hand increase in DRB103 was observed in the group of patients with C4AQ0, as compared with patients with other C4A allotypes (p = 0.047). There was no significant correlation between severe and mild disease, as judged by the SLEDAI, and HLADR, DQ alleles and comparing the patients with C4AQ0 with those with other C4A allotypes there was no significant difference regarding clinical manifestations.
The results are consistent with the argument that C4A deficiency contributes independently to susceptibility and the pathogenesis of SLE. C4A*Q0 in SLE patients in Iceland shows weaker linkage disequilibrium with DR3 genes than reported in most other white populations and emphasises the role of ethnicity.
在同质的白人群体中，对单个MHC基因在系统性红斑狼疮（SLE）发病机制中的相对贡献进行探索性分析。
测定了64例SLE患者及种族匹配的对照者的MHC II类等位基因和C4同种异型。采用序列特异性引物聚合酶链反应扩增进行HLA - DR和DQ分型。通过琼脂糖凝胶电泳测定C4同种异型。
患者中C4AQ0的频率显著高于对照者（46.9%对25.3%，p = 0.002）。SLE患者全组的HLA - DRB1、DQA1和DQB1等位基因与对照者无显著差异。另一方面，与具有其他C4A同种异型的患者相比，C4AQ0患者组中DRB103有所增加（p = 0.047）。根据SLEDAI判断，重症和轻症疾病与HLA - DR、DQ等位基因之间无显著相关性，并且比较C4AQ0患者与其他C4A同种异型患者，其临床表现无显著差异。
结果与C4A缺陷独立地导致SLE易感性和发病机制的观点一致。冰岛SLE患者中的C4A*Q0与DR3基因的连锁不平衡比大多数其他白人群体中报道的要弱，这强调了种族的作用。
