title: Association of the CTLA-4 1722TC polymorphism and systemic lupus erythematosus: a systematic review and meta analysis.
abstract: BACKGROUND
  Cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) is an important negative regulator of Tcell responses. The -1722TC polymorphism of the CTLA-4 gene may be associated with systemic lupus erythematosus (SLE) risk, but related results from previous studies have been inconsistent. We carried out a metaanalysis to assess this association more precisely.
  
  
  METHODS
  A systematic search through PubMed, Science Direct, and OVID, Iran doc, Iranmedex and SID (Scientific Information Database) databases was performed with the last search updated on December 30, 2011. The odds of ratio (OR) and its 95% confidence interval (95%CI) were used to assess the strength of the association. We evaluated both fixed and random effect models, depending on the presence of between-study heterogeneity. The analyses were conducted using STATA software, version 11.0.
  
  
  RESULTS
  A total of 9 independent studies on the CTLA-4 gene -1722TC polymorphism and SLE, including 1422 cases and 1417 controls were used in this meta-analysis. In the present meta-analysis, we found a significant association between -1722TC polymorphism and SLE risk in the overall analysis (TT versus
  OR=1.18, 95%CI 0.84-1.66, p= 0.32; TT/TC versus CC: OR = 2.06, 95%CI 1.07-3.99, p= 0.03; TT versus CC: OR = 2.32, 95%CI 1.62-3.32, p< 0.001; TC versus CC: OR = 1.99, 95%CI 1.42-2.78, p<0.001; TT versus TC: OR = 1.2, 95%CI 0.86-1.66,p= 0.28; T versus C: OR = 1.22, 95%CI 0.91-1.64,p= 0.16). In the subgroup analysis by ethnicity, -1722TC polymorphism was significantly associated with SLE risk in Asian population.
  
  
  CONCLUSIONS
  This meta-analysis suggests a significant association between -1722TC polymorphism and SLE susceptibility. Large-scale and well-designed case-control studies are necessary to validate the risk identified in the present meta-analysis.
authors.affiliation: 1. Instructor, Rheumatology Research Center, Tehran University of Medical Sciences, Tehran, Iran. mahdieh.shojaa_mw@yahoo.com.
authors.forename: Mahdieh
authors.initials: M
authors.lastname: Shojaa
authors.affiliation: 2. AssistantProfessor, Department of Medicine, Golestan University of Medical Sciences, Gorgan, Iran. mehrdad.aghaei@yahoo.com.
authors.forename: Mehrdad
authors.initials: M
authors.lastname: Aghaie
authors.affiliation: 3. Assistant Professor, Department of Community Medicine, Alborz University of Medical Sciences, Karaj, Iran & Non-Communicable Diseases Research Center, Endocrinology and Metabolism Population Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran. Mqorbani1379@yahoo.com.
authors.forename: Mostafa
authors.initials: M
authors.lastname: Qorbani
authors.affiliation: 4. PhD Candidate, Osteoporosis Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran. patricia.kh@gmail.com.
authors.forename: Patricia
authors.initials: P
authors.lastname: Khashayar
authors.affiliation: 5. Assistant Professor, Endocrinology and Metabolism Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of MedicalSciences, Tehran, Iran. amolimm@tums.ac.ir.
authors.forename: Mahsa
authors.initials: M
authors.lastname: Amoli
authors.affiliation: 6. Assistant Professor, Osteoporosis Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran. abkeshtkar@gmail.com.
authors.forename: Abbas Ali
authors.initials: AA
authors.lastname: Keshtkar
authors.affiliation: 7. Medical Doctor, Department of Internal Medicine, School of Medicine, Shahed University of Medical Sciences, Tehran, Iran. mehranmohebi@gmail.com.
authors.forename: Ramin
authors.initials: R
authors.lastname: Mohebi
authors.affiliation: 8. Assistant Professor, Health Promotion Research Center, Zahedan University of Medical Sciences, Zahedan, Iran. ansarih88@gmail.com.
authors.forename: Hossein
authors.initials: H
authors.lastname: Ansari
authors.affiliation: 9. Instructor, Department of Medical Emergencies, Qom University of Medical Sciences, Qom, Iran. asayeshpsy@gmail.com.
authors.forename: Hamid
authors.initials: H
authors.lastname: Asayesh
authors.affiliation: 10. Medical Doctor, Rheumatology Research Center, Tehran University of Medical Sciences, Tehran, Iran. roknsharifi.sh@gmail.com.
authors.forename: Shima
authors.initials: S
authors.lastname: RoknSharifi
keywords: 1722TC polymorphism; CTLA-4; Meta-analysis; Systemic lupus erythematosus (SLE)