The genetic influence of the nonclassical MHC molecule HLA-G on multiple sclerosis

Human leukocyte antigen (HLA)-G is a nonclassical major histocompatibility complex (MHC) molecule located at MHC complex at chromosome 6 and chiefly attributed immunoregulatory and tolerogenic functions. HLA-G is upregulated at sites of inflammation in multiple sclerosis (MS) and assumed to counterbalance immune responses. Different functionally relevant genetic variants of HLA-G have been described and shown to be statistically associated with human diseases such as fetal loss or sarcoidosis. We investigated the influence of three different variations in the HLA-G gene for disease susceptibility and course of MS (n = 698): (1) The -725 C/G exchange in the HLA-G promoter region, (2) HLA-G*0105N, a deletion that results in an irregular stopcodon in exon 3, and (3) a 14 bp insertion / deletion in the untranslated exon 8. None of these variations significantly influenced the susceptibility to multiple sclerosis. No association was seen with the age of onset of disease, disease severity or disease course. Although HLA-G is assumed to play an important role in the immunoregulatory processes of MS, our results do not support a role of genetic factors influencing disease susceptibility of the disease course.