Our meta-analysis showed that the FAS -670 A/G polymorphism was associated with the risk of autoimmune diseases (GG vs. GA: OR=1.079, 95% CI=1.004-1.160, P=0.038), especially in Caucasians (GG vs. GA: OR=1.12, 95% CI=1.03-1.23, P=0.012), Asians (G vs. A: OR=0.89, 95% CI=0.83-0.96, P=0.002), systemic lupus erythematosus (SLE) (G vs. A: OR=0.85, 95% CI=0.77-0.94, P=0.001), multiple sclerosis (MS) (GG+GA vs. AA: OR=0.83, 95% CI=0.70-0.99, P=0.043), systemic sclerosis (SSc) (GG vs. GA: OR=1.20, 95% CI=1.07-1.36, P=0.003) and Hashimoto's thyroiditis (HT) (G vs. A: OR=1.45, 95% CI=1.10-1.90, P=0.008); the FAS -1377 G/A polymorphism was associated with the risk of autoimmune diseases (A vs. G: OR=1.11, 95% CI=1.03-1.20, P=0.008), especially in Asians (A vs. G: OR=1.15, 95% CI=1.05-1.25, P=0.002) and high quality studies (A vs. G: OR=1.14, 95% CI=1.05-1.24, P=0.002).
In this connection, deficiency of vitamin D has been associated with several autoimmune diseases, including rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), antiphospholipid syndrome (APS), Hashimoto Thyroiditis (HT), and multiple sclerosis (MS).
Conversely, a protective role has also been described in other autoimmune diseases where humoral responses are detrimental such as myasthenia gravis (MG), Hashimoto's thyroiditis (HT), inflammatory bowel disease (IBD), and systemic lupus erythematosus (SLE).
CD40 rs1883832 is associated with decreased risk of Graves' disease, especially in Asian; CD40 rs1883832 is associated with increased risk of multiple sclerosis; CD40 -1C>T (rs1883832) is not associated with the susceptibility of Hashimoto's thyroiditis, systemic sclerosis or Asthma; there is insufficient data to fully confirm the association between CD40 rs1883832 and systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), Behçet's disease (BD), myasthenia gravis (MG), Crohn's disease (CD), ulcerative colitis (UC), Sarcoidosis, Fuch uveitis syndrome (FUS), Vogt-Koyanagi-Harada syndrome (VKH), Kawasaki disease (KD), giant cell arteritis (GCA) or Immune thrombocytopenia (ITP).
Families from the Lupus Multiplex Registry and Repository were studied in which there was at least 1 member who had both SLE and AITD (Graves' disease or Hashimoto thyroiditis).