title: Serum alpha-1 antitrypsin: a noninvasive marker of pouchitis.
abstract: BACKGROUND
  Patients with ulcerative colitis undergoing total proctocolectomy with ileal pouch-anal anastomosis may develop pouchitis. Alpha-1-antitrypsin (AAT) is an acute phase reactant produced mainly by hepatocytes, but also locally in the gut. Data on noninvasive biomarkers of pouchitis are scarce.
  
  
  METHODS
  To identify biomarkers that correlate with pouch inflammation, ulcerative colitis pouch patients were prospectively recruited and underwent clinical, endoscopic, and histologic evaluations. The Pouchitis Disease Activity Index (PDAI) was calculated, and pouchitis was defined by a score ≥7. Serum and fecal AAT, C-reactive protein (CRP), fecal calprotectin, ferritin and albumin levels were measured.
  
  
  RESULTS
  Seventy-one ulcerative colitis pouch patients (mean age 43.8 ± 8.3 yr, 50.7% males) were included. The main indication for ileal pouch-anal anastomosis was intractable colitis (83.1%). Median serum AAT level (183.0 mg/dL, 155.1-232.0) was significantly higher in patients with a PDAI ≥7 compared with those with a PDAI <7 (167.6 mg/dL, 151.0-181.0) (P = 0.03). Serum AAT, CRP, and fecal calprotectin levels significantly correlated with PDAI scores: r = 0.583, P < 0.001; r = 0.584, P < 0.001; and r = 0.606, P = 0.001, respectively. Serum AAT and CRP levels correlated significantly (r = 0.650, P < 0.001), as did serum AAT and fecal calprotectin levels (r = 0.663, P < 0.001). Fecal AAT levels did not correlate with any tested biomarker. Receiver operating characteristic analysis demonstrated sensitivity, specificity, and positive predictive value of 55.6%, 100%, and 100%, respectively, for diagnosing pouchitis at a serum AAT cutoff level of 189 mg/dL.
  
  
  CONCLUSIONS
  Serum AAT is a specific noninvasive biomarker of pouchitis. AAT levels correlate with disease activity and CRP and calprotectin levels.
authors: *IBD Center, Department of Gastroenterology and Liver Diseases and The Research Center for Digestive Tract and Liver Diseases, Tel Aviv Sourasky Medical Center, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel; †Department of Pathology, Tel-Aviv Sourasky Medical Center, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel; and ‡Proctology Unit, Division of Surgery, Tel-Aviv Sourasky Medical Center, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel.
authors: Shay
authors: S
authors: Matalon
authors: Hofit
authors: H
authors: Elad
authors: Eli
authors: E
authors: Brazowski
authors: Erwin
authors: E
authors: Santo
authors: Hagit
authors: H
authors: Tulchinsky
authors: Iris
authors: I
authors: Dotan
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood*; D002097:C-Reactive Protein / Q000032:analysis; D016022:Case-Control Studies; D002648:Child; D003093:Colitis, Ulcerative / Q000150:complications* / Q000601:surgery; D005260:Female; D006801:Humans; D039841:Leukocyte L1 Antigen Complex / Q000032:analysis; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D019449:Pouchitis / Q000097:blood / Q000175:diagnosis* / Q000209:etiology; D016737:Proctocolectomy, Restorative / Q000009:adverse effects*; D011379:Prognosis; D011446:Prospective Studies; D012720:Severity of Illness Index; D055815:Young Adult; D000515:alpha 1-Antitrypsin / Q000097:blood*
chemical_list: D015415:Biomarkers; D039841:Leukocyte L1 Antigen Complex; D000515:alpha 1-Antitrypsin; D002097:C-Reactive Protein