Interleukin-6-174G > C (rs1800795) polymorphism distribution and its association with rheumatoid arthritis: A case-control study and meta-analysis

• Published in: Autoimmunity (Chur, Switzerland) Switzerland), 2017-04, Vol.50 (3), p.158-169
• Main Authors: Dar, Sajad Ahmad, Haque, Shafiul, Mandal, Raju Kumar, Singh, Taru, Wahid, Mohd, Jawed, Arshad, Panda, Aditya K., Akhter, Naseem, Lohani, Mohtashim, Areeshi, Mohammed Yahya, Rai, Gargi, Datt, Shyama, Bhattacharya, Sambit Nath, Ramachandran, Vishnampettai Ganapathysubramanian, Das, Shukla
• Format: Article
• Language: English
• Subjects: Alleles; Arthritis, Rheumatoid - genetics; Arthritis, Rheumatoid - pathology; Case-Control Studies; Genetic Association Studies; Genetic Predisposition to Disease; Genotype; Humans; Interleukin-6; Interleukin-6 - genetics; meta-analysis; Odds Ratio; Polymorphism, Single Nucleotide; Population Groups - genetics; Publication Bias; rheumatoid arthritis; single nucleotide polymorphism; susceptibility
• ISSN: 0891-6934; 1607-842X
• DOI: 10.1080/08916934.2016.1261833

The association of interleukin-6 (IL-6)-174G > C (rs1800795) single nucleotide polymorphism (SNP) with the risk of acquiring rheumatoid arthritis (RA) is a relevant issue because of conflicting and consensus lacking reports published in literature. We investigated IL-6-174G > C promoter polymorphism in 34 RA patients, attending a tertiary care hospital in north India. We also performed a meta-analysis, of the previously published studies reporting this genetic relationship, in overall population, and independently in Asian and Caucasian ethnicities to further elucidate this association. A total of 13 studies, including the current one, involving 3291 RA cases and 3812 controls were analyzed. Out of the 13 studies, 6 were from Asian, 6 from Caucasian and 1 from a mixed population. Our case-control study showed significant association of IL-6-174G > C SNP with increased RA risk: allelic (OR = 3.750, 95% CI = 1.800-7.813, p  C SNP in overall population: allelic (OR = 1.650, 95% CI = 1.169-2.329, p = 0.004); homozygous (OR = 1.380, 95% CI = 0.906-2.101, p = 0.133); heterozygous (OR = 1.559, 95% CI = 1.001-2.428, p = 0.049); dominant (OR = 1.663, 95% CI = 1.078-2.567, p = 0.022); and recessive (OR = 1.366, 95% CI = 0.964-1.935, p = 0.079). Subgroup analysis also showed this polymorphism to be associated with increased RA risk in Asian population: allelic (OR = 3.724, 95% CI = 1.361-10.190, p = 0.010); dominant (OR = 3.823, 95% CI = 1.320-11.074, p = 0.013); and recessive (OR = 4.357, 95% CI = 1.634-11.623, p = 0.003), but not in Caucasian population. This meta-analysis shows that IL-6-174G > C SNP is significantly associated with increased RA risk in overall, and specifically in Asian population.