title: Relationship Between Cytomegalovirus Infection and Steroid Resistance in Inflammatory Bowel Disease: A Meta-Analysis.
abstract: OBJECTIVE
  Steroid resistance presents an administration difficulty in inflammatory bowel disease (IBD). The reason of steroid resistance is still unclear, but cytomegalovirus (CMV) infection may be a potential cause in some IBD patients. We carried out a meta-analysis to investigate the relationship between CMV infection and steroid-resistant IBD.
  
  
  METHODS
  The PubMed, EMBASE, and Cochrane Library databases were searched up to June 2014, with no language restrictions, for observational studies. Additional references were obtained from reviewed articles.
  
  
  RESULTS
  Eleven studies involving 867 IBD patients were included in the meta-analysis. Steroid resistance rate was 70.0% in CMV-positive IBD patients, which was significantly higher than that in CMV-negative IBD patients (RR = 2.12, 95% CI = 1.72-2.61). There was significant heterogeneity in the included eleven studies (I (2) = 57.6%). When the only one study with a few patients was excluded, sensitivity analysis suggested a similar outcome (RR = 2.07, 95% CI = 1.80-2.39, 10 studies). Based on the funnel plot and Egger's test, we considered that there was a probable publication bias.
  
  
  CONCLUSIONS
  Our meta-analysis suggests that CMV-positive IBD patients have a nearly double risk of steroid resistance compared with CMV-negative IBD patients, indicating that CMV infection is a probable cause of steroid-resistant IBD.
authors.affiliation: Department of Gastroenterology and Hepatology, Jinling Hospital, Medical School of Nanjing University, No. 305 Zhongshan East Road, Nanjing, 210002, Jiangsu Province, China.
authors.forename: Xiao-wei
authors.initials: XW
authors.lastname: Wu
authors.affiliation: Department of Gastroenterology and Hepatology, Jinling Hospital, Medical School of Nanjing University, No. 305 Zhongshan East Road, Nanjing, 210002, Jiangsu Province, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Wu
authors.affiliation: Department of Gastroenterology and Hepatology, Jinling Hospital, Medical School of Nanjing University, No. 305 Zhongshan East Road, Nanjing, 210002, Jiangsu Province, China.
authors.forename: Hong-zan
authors.initials: HZ
authors.lastname: Ji
authors.affiliation: Department of Gastroenterology and Hepatology, Jinling Hospital, Medical School of Nanjing University, No. 305 Zhongshan East Road, Nanjing, 210002, Jiangsu Province, China. Wangfangyu2014@126.com.
authors.forename: Fang-yu
authors.initials: FY
authors.lastname: Wang
mesh_terms: D000328:Adult; D003586:Cytomegalovirus Infections / Q000175:diagnosis / Q000453:epidemiology*; D004351:Drug Resistance; D005260:Female; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000175:diagnosis / Q000188:drug therapy* / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D018570:Risk Assessment; D012307:Risk Factors; D013256:Steroids / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: D013256:Steroids
keywords: Crohn’s disease; Cytomegalovirus; Inflammatory bowel disease; Meta-analysis; Ulcerative colitis