title: Interleukin-6-174G > C (rs1800795) polymorphism distribution and its association with rheumatoid arthritis: A case-control study and meta-analysis.
abstract: 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 < 0.001); dominant (OR = 2.800, 95% CI = 1.167-6.721, p = 0.021); and recessive (OR = 36.72, 95% CI = 2.004-672.7, p = 0.015). The meta-analysis revealed the increased RA risk associated with IL-6-174G > 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.
authors.affiliation: a Department of Microbiology , University College of Medical Sciences (University of Delhi) & GTB Hospital , Delhi , India.|b Research and Scientific Studies Unit, College of Nursing & Allied Health Sciences, University of Jazan , Jazan , Saudi Arabia.
authors.forename: Sajad Ahmad
authors.initials: SA
authors.lastname: Dar
authors.affiliation: b Research and Scientific Studies Unit, College of Nursing & Allied Health Sciences, University of Jazan , Jazan , Saudi Arabia.
authors.forename: Shafiul
authors.initials: S
authors.lastname: Haque
authors.affiliation: b Research and Scientific Studies Unit, College of Nursing & Allied Health Sciences, University of Jazan , Jazan , Saudi Arabia.
authors.forename: Raju Kumar
authors.initials: RK
authors.lastname: Mandal
authors.affiliation: a Department of Microbiology , University College of Medical Sciences (University of Delhi) & GTB Hospital , Delhi , India.
authors.forename: Taru
authors.initials: T
authors.lastname: Singh
authors.affiliation: b Research and Scientific Studies Unit, College of Nursing & Allied Health Sciences, University of Jazan , Jazan , Saudi Arabia.
authors.forename: Mohd
authors.initials: M
authors.lastname: Wahid
authors.affiliation: b Research and Scientific Studies Unit, College of Nursing & Allied Health Sciences, University of Jazan , Jazan , Saudi Arabia.
authors.forename: Arshad
authors.initials: A
authors.lastname: Jawed
authors.affiliation: c Centre for Life Sciences, Central University of Jharkhand , Brambe , Ranchi , Jharkhand , India.
authors.forename: Aditya K
authors.initials: AK
authors.lastname: Panda
authors.affiliation: d Department of Laboratory Medicine , Faculty of Applied Medical Sciences, Albaha University , Albaha , Saudi Arabia , and.
authors.forename: Naseem
authors.initials: N
authors.lastname: Akhter
authors.affiliation: b Research and Scientific Studies Unit, College of Nursing & Allied Health Sciences, University of Jazan , Jazan , Saudi Arabia.
authors.forename: Mohtashim
authors.initials: M
authors.lastname: Lohani
authors.affiliation: b Research and Scientific Studies Unit, College of Nursing & Allied Health Sciences, University of Jazan , Jazan , Saudi Arabia.
authors.forename: Mohammed Yahya
authors.initials: MY
authors.lastname: Areeshi
authors.affiliation: a Department of Microbiology , University College of Medical Sciences (University of Delhi) & GTB Hospital , Delhi , India.
authors.forename: Gargi
authors.initials: G
authors.lastname: Rai
authors.affiliation: a Department of Microbiology , University College of Medical Sciences (University of Delhi) & GTB Hospital , Delhi , India.
authors.forename: Shyama
authors.initials: S
authors.lastname: Datt
authors.affiliation: e Department of Dermatology , University College of Medical Sciences (University of Delhi) & GTB Hospital , Delhi , India.
authors.forename: Sambit Nath
authors.initials: SN
authors.lastname: Bhattacharya
authors.affiliation: a Department of Microbiology , University College of Medical Sciences (University of Delhi) & GTB Hospital , Delhi , India.
authors.forename: Vishnampettai Ganapathysubramanian
authors.initials: VG
authors.lastname: Ramachandran
authors.affiliation: a Department of Microbiology , University College of Medical Sciences (University of Delhi) & GTB Hospital , Delhi , India.
authors.forename: Shukla
authors.initials: S
authors.lastname: Das
mesh_terms: D000483:Alleles; D001172:Arthritis, Rheumatoid / Q000235:genetics* / Q000473:pathology*; D016022:Case-Control Studies; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D015850:Interleukin-6 / Q000235:genetics*; D016017:Odds Ratio; D020641:Polymorphism, Single Nucleotide; D044382:Population Groups / Q000235:genetics; D017594:Publication Bias
chemical_list: D015850:Interleukin-6
keywords: Interleukin-6; meta-analysis; rheumatoid arthritis; single nucleotide polymorphism; susceptibility