Relation of the Fas and FasL gene polymorphisms with susceptibility to and severity of rheumatoid arthritis.

To investigate associations of the Fas and FasL genes polymorphisms with rheumatoid arthritis (RA). One hundred patients with RA and age-, sex- and ethnically matched 101 controls were included. Four polymorphisms of Fas (-670 A>G rs1800682, -1377 G>A rs2234767) and FasL (IVS2nt-124 A>G rs5030772, -844 T>C rs763110) genes were typed from genomic DNA. Genotype distributions and allelic frequencies were compared between patients and control subjects. After the history and clinical examination of patients with RA, in terms of pain, fatigue and general health status were evaluated by visual analogue scale. Thereafter, erythrocyte sedimentation rate, C-reactive protein, blood count and rheumatoid factor levels were measured. The Disease Activity Score-28, Health Assessment Questionnaire and modified Sharp score were used to evaluate the disease activity, functional disability and radiological damage, and their relationships with the Fas and FasL gene polymorphisms were investigated. In patients with RA, CT and TT genotypes of FasL-844, polymorphism were twofold and 4.8-fold higher, and AA genotype of FasL IVS2nt-124 polymorphism was 3.4-fold higher than the control group (respectively, p = 0.05, p = 0.002, p = 0.039). T allele of FasL-844 polymorphism was more frequent in patients than controls (respectively, 52.5 vs. 41.4 %, p = 0.027). Any association was not detected between Fas (-670 A>G, -1377 G>A) and FasL (-844 T>C, IVS2nt-124 A>G) gene polymorphisms with the disease activity scores, functional disability and radiological damage. However, the Fas-670 A>G polymorphism was associated with drug therapy (p = 0.049). The distribution of GG genotype was higher compared to GA or AA genotypes in patients using triple disease-modifying antirheumatic drug therapy (71.4, 14.3 and 14.3 %, respectively). These findings suggest that the -844 T>C and IVS2nt-124 A>G polymorphisms in the FasL gene related with apoptosis may increase genetic susceptibility to RA in a Turkish population. In addition, the Fas-670 A>G gene polymorphism may be associated with disease progression. There is a need for further studies to clarify the genetic role of apoptosis in RA.

Apoptosis-related Fas and FasL gene polymorphisms' associations with knee osteoarthritis.

To investigate the associations between Fas and FasL gene polymorphisms and susceptibility to knee osteoarthritis. Genomic DNA was obtained from 146 patients with knee osteoarthritis and 102 healthy controls. Genotype distributions and allelic frequencies of four polymorphisms of Fas (-670 G>A rs1800682, -1377 G>A rs2234767) and FasL (IVS2nt-124 A>G rs5030772, -844 T>C rs763110) genes were compared between the groups. Thereafter, this association was investigated between patients and controls of the same sex. There were significant differences between patients with knee osteoarthritis and controls regarding the genotype distributions and allelic frequencies of Fas-1377 G>A polymorphism (P = 0.0001 and P = 0.005, respectively). The Fas-1377 GG genotype and G allele were significantly more frequent in patients with knee osteoarthritis than in controls. Genotype distributions and allelic frequencies of Fas-670 G>A, FasL-844 T>C, and FasL IVS2nt-124 A>G polymorphisms did not differ between the groups (P > 0.05). However, there were no significant differences between patients and controls of the same sex (P > 0.05). These findings suggest that the Fas-1377 G>A polymorphism in the Fas gene related with apoptosis may contribute to susceptibility to knee osteoarthritis in the Turkish population. There is a need for further studies to evaluate the role of apoptosis in large cohorts.