Trudy M. Doyle

Uveitis in patients with sarcoidosis is not associated with mutations in NOD2 (CARD15)

PURPOSE Mutations in NOD2 are responsible for Blau syndrome, a systemic disease triad involving the uvea, joints, and skin. NOD2 mutations are also associated with Crohn disease. Both Blau syndrome and Crohn disease involve granulomatous inflammation and uveitis, as does sarcoidosis. We sought to determine if NOD2 mutations were present in patients with sarcoidosis, especially those with uveitis. METHODS NOD2 gene exons were sequenced from DNA obtained from sarcoidosis patients. The diagnoses of sarcoidosis and uveitis were verified from clinical records. RESULTS NOD2 polymorphisms were found in 26 patients with sarcoidosis (13 with uveitis). There was no significant difference in allele frequencies between patients with and without uveitis. CONCLUSIONS Despite the strikingly similar pathologies of Blau syndrome and sarcoidosis, no mutations were found to be associated with sarcoidosis in a group of patients, regardless of the presence of uveitis.

Association of interleukin 23 receptor gene with sarcoidosis

Interleukin 23 receptor (IL23R) gene has been reported as a genetic factor strongly associated with inflammatory bowel disease, psoriasis, and ankylosing spondylitis. We investigated the association between IL23R gene single nucleotide polymorphisms (SNPs) and susceptibility to sarcoidosis, including the clinical manifestation of uveitis. Ninety-one sarcoidosis subjects (58 with and 33 without uveitis) and 104 healthy controls were genotyped for eleven IL23R SNPs. DNA was amplified using specific PCR primers and genotyped by denaturing HPLC and/or direct DNA sequencing. Case-control frequency comparisons were analyzed using Chi square test. Three IL23R SNPs, rs7517847 (intron 6), rs11465804 (intron 8), and rs11209026 (exon 9, c.1142G>A, p.Arg381Gln) were associated with sarcoidosis in our population (p < 0.05): rs7517847 showed increased frequencies in sarcoidosis compared to controls, but rs11465804 and rs11209026 were decreased. Two of these SNPs were associated with the uveitis subgroup compared to controls: rs11465804 (0.9% vs. 7.2%, OR = 0.11, P = 0.013) and rs11209026 (1.8% vs. 7.3%, OR = 0.23, P = 0.038). This finding indicates the association of IL23R polymorphism with sarcoidosis, especially with sarcoid uveitis. IL23R may be a common susceptibility gene shared by several autoimmune disorders including inflammatory bowel disease, psoriasis, and ankylosing spondylitis and sarcoid uveitis.