Study: RA, bad genes and dry eye

This is one of those numbers-heavy studies relating dryness in rheumatoid arthritis patients to genes... of interest perhaps to the research diehards if not to me personally....

[The presence of dry eye syndrome and corneal complications in patients with rheumatoid arthritis and its association with -174 gene polymorphism for interleukin 6]
Polanská V, Serý O, Fojtík Z, Hlinomazová Z.
Cesk Slov Oftalmol. 2008 Mar;64(2):77-80

The aim of this study was to evaluate the presence of the dry eye syndrome and corneal complications in patients with rheumatoid arthritis and to assess its association with the -174 gene polymorphism for interleukin 6. The group consisted of 123 patients treated for rheumatoid arthritis (20 men, 103 women); the mean age was 53 years (+/- 13.6). Every patient had completely ophthalmologic examination and special attention was paid to the amount of tears. The presence of corneal complications was detected in the medical history and evaluated during the slit lamp examination. In all patients the polymorphism-174 IL-6 examinations were performed. For the statistical data processing, the chi square (chi2) test for nominal variable was used. The dry eye syndrome (DES) was found in 98 eyes (79.7%), severe dry eye syndrome was detected in 53 patients (43.1%). Corneal complications appeared in 9 patients (7.3%). DES was present in 32 patients with the GG genotype (91.4%, n1 = 35), in 49 patients with the CG genotype (71.0%, n2 = 69), and in 8 patients with the CC genotype (42.1%, n3 = 19). After the statistical evaluation we have found the association between the dry eye syndrome and the GG genotype (chi2 = 8.9) and the association between less common dry eye syndrome appearance and the presence of the CC genotype (chi2 = 10.3). Severe dry eye syndrome we proved in 18 patients with GG genotype (51.4%, n1 = 35), in 31 patients with CG genotype (44.9%, n2 = 69), and in 4 patients with CC genotype CC (21.1%, n3 = 19). We proved statistically significant association between CC genotype and less often appearance of the severe dry eye syndrome (chi2 = 4.45). Corneal complications we noticed in one patient with GG genotype (2.8%, n1 = 35), in 5 patients with CG genotype (7.2%, n2 = 69), and in 3 patients with CC genotype (15.8%, n3 = 19). We did not prove statistically significant association between the 174 IL-6 polymorphism and corneal complications appearance. The 174 IL-6 polymorphism influences the appearance of the dry eye syndrome. In patients with GG genotype of the -174 gene polymorphism for IL-6 is its appearance more common. Patients with the rheumatoid arthritis and with CC genotype of the -174 gene IL-6 polymorphism have lower frequency of the dry eye syndrome presence.