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Objective To investigate whether polymorphisms in Toll-like receptor (TLR) genes, previously reported to be associated with immune-mediated diseases, are involved in systemic sclerosis (SSc). Methods We genotyped 14 polymorphisms in the genes for TLRs 2, 4, 7, 8, and 9 in a discovery cohort comprising 452 SSc patients and 537 controls and a replication cohort consisting of 1,170 SSc patients and 925 controls. In addition, we analyzed 15-year followup data on 964 patients to assess the potential association of TLR variants with the development of disease complications. We analyzed the functional impact of the associated polymorphism on monocyte-derived dendritic cells. Results In the discovery cohort, we observed that a rare functional polymorphism in TLR2 (Pro631His) was associated with antitopoisomerase (antitopo) positivity (odds ratio 2.24 [95% confidence interval 1.24-4.04], P = 0.003). This observation was validated in the replication cohort (odds ratio 2.73 [95% confidence interval 1.85-4.04], P = 0.0001). In addition, in the replication cohort the TLR2 variant was associated with the diffuse subtype of the disease ( P = 0.02) and with the development of pulmonary arterial hypertension (PAH) (Cox proportional hazards ratio 5.61 [95% confidence interval 1.53-20.58], P = 0.003 by log rank test). Functional analysis revealed that monocyte-derived dendritic cells carrying the Pro63His variant produced increased levels of inflammatory mediators (tumor necrosis factor α and interleukin-6) upon TLR-2-mediated stimulation (both P < 0.0001). Conclusion Among patients with SSc, the rare TLR2 Pro631His variant is robustly associated with antitopoisomerase positivity, the diffuse form of the disease, and the development of PAH. In addition, this variant influences TLR-2-mediated cell responses. Further research is needed to elucidate the precise role of TLR-2 in the pathogenesis of SSc. [ABSTRACT FROM AUTHOR]

Objective: To investigate the role of the Fc(α)RI 844 A>G functional polymorphism in the genetic predisposition to rheumatoid arthritis (RA) and systemic sclerosis (SSc) susceptibility., Methods: The study population was composed of 1401 patients with SSc, 642 patients with RA, and 1317 healthy controls. The Fc(α)RI (CD89) single-nucleotide polymorphism rs16986050 was genotyped by pyrosequencing., Results: We observed no significant deviation of the genotype and allele frequencies in RA and SSc compared to controls. A metaanalysis and a recessive and dominant model yielded similar negative results., Conclusion: Our data show that the Fc(α)RI 844 A>G polymorphism is not associated with SSc or RA susceptibility.

Objective: To investigate the possible role of FCGR2A 519A>G and FCGR3A 559A>C functional polymorphisms in the genetic predisposition to susceptibility to systemic sclerosis (SSc) or clinical phenotype., Methods: A total of 1566 patients with SSc and 2271 geographically matched controls were included in our study. We analyzed the genotype and allele frequencies of the FCGR2A 519A>G and FCGR3A 559A>C functional variants in 6 independent European cohorts of white patients with SSc, and white controls. The cohorts comprised 165 Dutch patients with SSc and 1326 controls, 236 Spanish patients with SSc and 257 controls, 267 German patients with SSc and 270 controls, 202 Swedish patients with SSc and 261 controls, 416 Italian patients with SSc and 157 controls, and additionally 280 English patients with SSc. Genotyping was performed using Taqman 5' allelic discrimination assay. The study reached a 99% power to detect the effect of a polymorphism at an OR of 1.3., Results: Neither FCGR2A 519A>G nor FCGR3A 559A>C was significantly associated with susceptibility to SSc. We did not find an association with specific disease phenotypes, limited or diffuse cutaneous involvement, autoantibody profiles, or pulmonary involvement., Conclusion: Our study strongly suggests the lack of a role for the FCGR2A 519A>G and FCGR3A 559A>C polymorphisms in SSc susceptibility or clinical phenotype in 6 independent European cohorts.