Human leucocyte antigen-G (HLA-G) is a nonclassical class I major histocompatibility complex (MHC) molecule characterized by complex immunoregulatory and tolerogenic functions. Membrane-bound HLA-G is expressed on the surface of different cell populations in both physiological and pathological conditions. Systemic sclerosis (SSc) is a multisystem autoimmune disease characterized by widespread tissue fibrosis, vascular lesions and immunological alterations. Systemic lupus erythematosus is the prototypic systemic autoimmune disease affecting virtually any organ system, such as skin, joints, central nervous system, or kidneys. In SSc and SLE patients, the membrane expression of HLA-G on monocytes (0.88 ± 1.54 and 0.43 ± 0.75, respectively), CD4+ (0.42 ± 0.78 and 0.63 ± 0.48, respectively), CD8+ (2.65 ± 3.47 and 1.29 ± 1.34, respectively) and CD4+ CD8+ double-positive cells (13.87 ± 15.97 and 3.79 ± 3.11, respectively) was significantly higher than in healthy controls (0.12 ± 0.07; 0.01 ± 0.01; 0.14 ± 0.20 and 0.32 ± 0.38, respectively) (p < 0.0001). Our results show that in SSc and SLE the membrane expression of HLA-G by different subpopulations of peripheral blood mononuclear cells (PBMC) is increased, suggesting a potential role of HLA-G molecules in the complex immunological pathogenesis of these two autoimmune disorders.

人白细胞抗原-G（HLA-G）是一种非经典的I类主要组织相容性复合物（MHC）分子，其特征在于具有复杂的免疫调节和致耐受功能。膜结合的HLA-G在生理和病理条件下均在不同细胞群体的表面表达。系统性硬化症（SSc）是一种多系统自身免疫性疾病，其特征在于广泛的组织纤维化，血管病变和免疫学改变。系统性红斑狼疮是一种原型系统性自身免疫性疾病，几乎影响任何器官系统，例如皮肤，关节，中枢神经系统或肾脏。在SSc和SLE患者中，HLA-G在单核细胞（分别为0.88±1.54和0.43±0.75），CD4 +（分别为0.42±0.78和0.63±0.48），CD8 +（2.65±3.47和1.29±1.34，和CD4 + CD8 +双阳性细胞（分别为13.87±15.97和3.79±3.11）显着高于健康对照组（分别为0.12±0.07; 0.01±0.01; 0.14±0.20和0.32±0.38）（p <0.0001 ）。我们的结果表明，在SSc和SLE中，外周血单个核细胞（PBMC）不同亚群的HLA-G膜表达增加，表明HLA-G分子在这两种自身免疫性疾病的复杂免疫发病机制中具有潜在作用。