O papel do gene e da molécula HLA-G na express？o clínica das doen？as reumatológicas

human leukocyte antigen g (hla-g) is a non-classic class i major histocompatibility complex (mhc) molecule characterized by low polymorphism in its coding region, a limited tissue distribution pattern in physiologic conditions, and expression through soluble isoforms and isoforms bound to surface membranes through alternative splicing. hla-g is fairly known since it is involved in induction and maintenance of tolerance between the maternal immunologic system and the semi-allogeneic fetus at the level of the fetal-placental interface. besides, several studies have indicated a wider immunoregulatory role of this molecule. in this context, the expression of hla-g in inflammatory and rheumatologic diseases is a relatively recent research area. the first studies described the expression of hla-g in several inflammatory myopathies, atopic dermatitis, and cutaneous psoriasis. based on the findings that hla-g could divert t helper responses to the th2 type, it was hypothesized that hla-g would be a protective molecule in inflammatory responses. in this article, we review the potential roles of the hla-g molecule in the immune system and in several rheumatologic diseases, such as systemic lupus erythematosus, rheumatoid arthritis, systemic sclerosis, and others