title: pANCA positivity predicts lower clinical response to infliximab therapy among patients with IBD.
abstract: OBJECTIVE
  Several studies have been performed evaluating the role of perinuclear anti-neutrophil cytoplasmic antibodies (pANCA) to predict early clinical response among patients with inflammatory bowel disease (IBD) who are undergoing infliximab therapy. The results of these studies are variable, however, and the effect of pANCA+ as a predictor of clinical response to infliximab remains largely undefined. The goal of this meta-analysis was to evaluate the role of pANCA in predicting poor responders to infliximab.
  
  
  METHODS
  A comprehensive search of the PubMed/MEDLINE, Scopus, Cumulative Index of Nursing and Allied Health Literature, Google Scholar, and Cochrane databases was performed in June 2014. All of the studies that evaluated pANCA levels in patients with IBD who were undergoing antitumor necrosis factor-α (anti-TNF-α) therapy and their clinical responses were included. A meta-analysis was performed using the Mantel-Haenszel model with odds ratios to assess for clinical remission.
  
  
  RESULTS
  In the pooled analysis (N = 415), patients who were pANCA negative had nearly a twofold higher response to anti-TNF-α therapy compared with patients who were pANCA+ (odds ratio 1.87; 95% confidence interval 1.02-3.41). Serologic testing for pANCA+ predicting nonresponse to infliximab therapy showed a sensitivity of 25.2%, a specificity of 85.5%, a positive predictive value of 41.1%, and a negative predictive value of 74.0%.
  
  
  CONCLUSIONS
  Being more proactive (ie, early dose escalation or accelerated loading regimen) in patients who are pANCA+ may be necessary to improve clinical response.
authors.affiliation: From the Departments of Medicine and Pharmacy, University of California, Irvine, and the Department of Medicine, University of Missouri, Columbia.
authors.forename: Douglas L
authors.initials: DL
authors.lastname: Nguyen
authors.affiliation: From the Departments of Medicine and Pharmacy, University of California, Irvine, and the Department of Medicine, University of Missouri, Columbia.
authors.forename: Emily T
authors.initials: ET
authors.lastname: Nguyen
authors.affiliation: From the Departments of Medicine and Pharmacy, University of California, Irvine, and the Department of Medicine, University of Missouri, Columbia.
authors.forename: Matthew L
authors.initials: ML
authors.lastname: Bechtold
mesh_terms: D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use*; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000097:blood*; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D015415:Biomarkers / Q000097:blood; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000097:blood / Q000188:drug therapy* / Q000276:immunology; D000069285:Infliximab; D016017:Odds Ratio; D016896:Treatment Outcome
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D019268:Antibodies, Antineutrophil Cytoplasmic; D000911:Antibodies, Monoclonal; D015415:Biomarkers; D000069285:Infliximab