INFLAMMATORY BOWEL DISEASE ORIGINAL CONTRIBUTIONS

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1 ORIGINAL CONTRIBUTIONS nature publishing group 881 see related editorial on page 888 Consecutive Monitoring of Fecal and for the Early Diagnosis and Prediction of Pouchitis after Restorative Proctocolectomy for Ulcerative Colitis Takayuki Yamamoto, MD, PhD, FACG 1, Takahiro Shimoyama, MD 1, Takuya Bamba, MD 1 and Koichi Matsumoto, MD, PhD 1 OBJECTIVES: METHODS: This prospective study was conducted to evaluate the significance of consecutive monitoring of fecal calprotectin and lactoferrin for the early diagnosis and prediction of pouchitis after restorative proctocolectomy for ulcerative colitis (UC). Sixty patients who had ileostomy closure following total proctocolectomy and ileal pouch-anal anastomosis for UC were included. Stool samples were collected for the measurement of calprotectin and lactoferrin every 2 months up to 12 months after the ileostomy closure. When patients had symptoms suggestive of pouchitis, endoscopic examination was immediately undertaken. All asymptomatic patients underwent endoscopy at 12 months. Pouchitis was defined as a pouchitis disease activity index score of 7. RESULTS: During the 12 months, 1 patients (17%) developed pouchitis. In patients with pouchitis, fecal calprotectin and lactoferrin levels were elevated already 2 months before the diagnosis of pouchitis. In contrast, these fecal biomarkers remained at low levels, and they did not change significantly in patients without pouchitis. A cutoff value of 56 μ g/g for calprotectin had a sensitivity of 1% and a specificity of 84% to predict pouchitis, whereas a cutoff value of 5 μ g/g for lactoferrin had a sensitivity of 9% and a specificity of 86%. At the time of endoscopy, the median calprotectin and lactoferrin levels were significantly higher in patients with pouchitis than those without pouchitis. CONCLUSIONS: Elevated fecal calprotectin and lactoferrin levels appeared to be significant predictors of pouchitis after restorative proctocolectomy for UC. Consecutive monitoring of these fecal biomarkers is useful for the early diagnosis of pouchitis. Am J Gastroenterol 215; 11: ; doi: 1.138/ajg ; published online 28 April 215 INTRODUCTION Ileal pouch-anal anastomosis is currently accepted as the standard method to restore continence after total proctocolectomy for medically refractory ulcerative colitis (UC) and familial adenomatous polyposis ( 1 ). Pouchitis is the most common complication of total proctocolectomy and ileal pouch-anal anastomosis in UC (2 ). The incidence of a first episode of pouchitis at 1, 5, and 1 years postoperatively is 15, 33, and 45%, respectively ( 2,3 ). A variety of pathophysiological mechanisms have been proposed for pouchitis, but the precise pathogenesis remains unknown. The use of noninvasive biomarkers for the diagnosis and management of inflammatory bowel disease (IBD) has been increasing. is a neutrophil cytosolic protein with antimicrobial properties, which is present at an increased concentration in stool during bowel inflammation (4 ). The stability of the protein to degradation keeps it stable in feces for up to 7 days at room temperature, making it an ideal analyte ( 5 ). is an iron-binding glycoprotein and a major component of the secondary granules of polymorphonuclear neutrophils ( 6 ). During intestinal inflammation, leukocytes invade the mucosa, which may lead to an increase in the excretion of lactoferrin into the stool. can be measured by using simple and inexpensive techniques, as it is stable in the stool for up to 5 days. Fecal calprotectin and lactoferrin are highly sensitive and specific biomarkers for detecting intestinal inflammation (7 ). These fecal 1 Infl ammatory Bowel Disease Center, Yokkaichi Hazu Medical Center, Yokkaichi, Mie, Japan. Correspondence: Takayuki Yamamoto, MD, PhD, FACG, Infl ammatory Bowel Disease Center, Yokkaichi Hazu Medical Center, 1-8 Hazuyamacho, Yokkaichi, Mie 51-16, Japan. nao-taka@sannet.ne.jp Received 22 December 214 ; accepted 3 March by the American College of Gastroenterology The American Journal of GASTROENTEROLOGY

2 882 Yamamoto et al. biomarkers showed a close correlation with endoscopic inflammation in patients with IBD ( 8,9 ). Further, elevated fecal calprotectin and lactoferrin levels were associated with subsequent clinical relapse ( 1 ). Fecal calprotectin and lactoferrin determination may be useful in predicting clinical relapse in patients with IBD ( 11,12 ). A few studies ( ) have been carried out to evaluate the value of fecal calprotectin or lactoferrin measurement in patients with pouchitis after restorative proctocolectomy for UC. In these studies, fecal calprotectin or lactoferrin level was determined by only one test using a single stool sample ( ). So far, no studies have consecutively measured the levels of fecal calprotectin and lactoferrin in patients after ileal pouch surgery. Therefore, the value of consecutive fecal calprotectin and lactoferrin measurements after restorative proctocolectomy remains unknown. This prospective study was designed to evaluate the significance of consecutive monitoring of fecal calprotectin and lactoferrin for the early diagnosis and prediction of pouchitis after restorative proctocolectomy for UC. METHODS Study design This was a prospective, single-center study undertaken at the Yokkaichi Hazu Medical Center, a referral center treating a large number of patients with IBD. The study was conducted in accordance with good clinical practice and the Declaration of Helsinki principles. Our study protocol was reviewed and approved by our Institutional Review Board. Patients Inclusion criteria were as follows: (i) patients who were between 2 and 7 years of age; (ii) patients who were diagnosed with histologically confirmed UC; and (iii) patients who had ileostomy closure following total proctocolectomy and ileal pouch-anal anastomosis for medically refractory UC. Exclusion criteria were as follows: (i) patients who developed pouch-related complications (anastomotic leak, pelvic abscess, pouch fistula, anastomotic stricture); and (ii) patients who were taking antibiotics, nonsteroidal anti-inflammatory agents, 5-aminosalicylic acids, corticosteroids, or immunosuppressive medications within 1 month of the entry to the study. A total of 6 patients who met the inclusion criteria were included in this study. Baseline characteristics of the 6 eligible patients are shown in Table 1. All patients underwent a total proctocolectomy and ileal pouch-anal anastomosis with a covering ileostomy. Postoperatively, all patients were in good health, were off steroid medication, and regained their normal body weight. At 3 months after restorative proctocolectomy, ileostomy closure was performed. Clinical assessment All patients were reviewed in our clinic every 2 months up to 12 months after the ileostomy closure. At the clinic visits, clinical assessment was performed according to the component of symptom in a Pouchitis Disease Activity Index (PDAI) ( 17 ); stool frequency, rectal bleeding, fecal urgency, abdominal cramps, and fever. During the study period, patients were not allowed to take antibiotics, nonsteroidal anti-inflammatory agents, 5-aminosalicylic Table 1. Baseline characteristics of 6 patients Median (range) age at entry 34 (21 64) years Male:female ( n ) 37:23 Median (range) duration of UC before proctocolectomy Preoperative medications for UC ( n) 51 (13 112) months 5-aminosalicylic acid 57 (95%) Corticosteroids (prednisolone 2 6 mg/day) 56 (93%) Azathioprine or 6-mercaptopurine 32 (53%) Tacrolimus 1 (17%) Infl iximab 7 (12%) Extent of UC ( n) Left-sided colitis 24 (4%) Extensive colitis a 36 (6%) Extraintestinal manifestations ( n) Arthritis 7 (12%) Pyoderma gangrenosum 2 (3%) UC, ulcerative colitis. a Involvement extends proximal to the splenic fl exure. acids, corticosteroids, or immunosuppressive medications before the diagnosis of pouchitis. In our clinic, peripheral blood samples were collected for the measurement of white blood cell (WBC) count, hemoglobin, platelet count, C-reactive protein (CRP), total protein, albumin, creatinine, urea, sodium, potassium, chloride, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, lactic dehydrogenase, total bilirubin, and cholesterol. Endoscopic examination When patients had clinical symptoms suggestive of pouchitis (increased stool frequency, urgency, tenesmus, incontinence, nocturnal seepage, abdominal cramping, and pelvic discomfort) at the clinic visits, endoscopic examination was immediately undertaken. In contrast, all asymptomatic patients underwent endoscopy at the end of this study (12 months after the ileostomy closure). During the endoscopy, the biopsies were obtained from the ileal pouch in each patient. The endoscopic and histologic severities of the mucosal inflammation were assessed according to the components of endoscopic findings and histologic findings in the PDAI, respectively. Pouchitis was defined as a PDAI score (maximum score: 18) of 7. Endoscopists were blinded to the results of fecal biomarkers. Measurement of fecal calprotectin and lactoferrin Patients provided a stool sample for the measurement of calprotectin and lactoferrin at the clinic visits, every 2 months after the ileostomy closure. Fecal calprotectin was measured by a quantitative enzyme immunoassay (Human enzyme-linked immunosorbent assay Kit, Cell Sciences, Canton, MA). was measured by a colloidal gold agglutination reagent (Auto The American Journal of GASTROENTEROLOGY VOLUME 11 JUNE 215

3 Fecal Biomarkers and Pouchitis in UC 883 Lf-Plus, Alfresa Pharma, Osaka, Japan) by using a high-throughput discrete clinical chemistry analyzer (Hemo Techt NS-Plus C, Alfresa Pharma). Laboratory personnel were blinded to the clinical data. diagnosed with pouchitis (PDAI score: median 3, range 6). No patient went on to develop Crohn s disease in the ileal pouch during this study. Statistical analysis Comparisons of frequencies were analyzed using the χ 2 test with Yates correction. Differences between median values were compared using the Mann Whitney U -test or the Kruskal Wallis test if more than two groups were compared. The change in median values with time was evaluated by Wilcoxon signed rank test. Correlations were calculated by using the Spearman s r-test. P <.5 was considered to be statistically significant. To determine an optimal cutoff value for the prediction of pouchitis, a receiver operating characteristic (ROC) curve was constructed. The ROC curve is a plot of the true positive rate (sensitivity) against the false positive rate (1 specificity) for the different possible cutoffs of a diagnostic test. The closer the curve follows the left-hand border and then the top border of the ROC space, the more accurate the test. We defined the most optimal cutoff point by looking at the sensitivity and specificity for different cutoff values. RESULTS Pouchitis During the study period, 13 patients (22%) developed clinical symptoms suggestive of pouchitis. Endoscopic examination was undertaken in the 13 patients, of whom 1 (17%) were diagnosed with pouchitis (PDAI score: median 11, range 8 14). The duration from the ileostomy closure to the diagnosis of pouchitis was 6 months in 1 patient, 8 months in 3 patients, 1 months in 4 patients, and 12 months in 2 patients (median: 1 months). In the remaining 3 symptomatic patients, there was no apparent inflammation in the ileal pouch, and the PDAI score was <7. Asymptomatic patients underwent endoscopic examination at 12 months after the ileostomy closure, and none of them were Fecal biomarkers before the diagnosis of pouchitis The changes in the median fecal calprotectin and lactoferrin levels in 1 patients with pouchitis are shown in Figure 1. Between 4 and 1 months before the diagnosis of pouchitis, the median fecal calprotectin and lactoferrin levels did not significantly change with time (all comparisons: P >.5), and remained at low levels. However, these levels were significantly elevated 2 months before the diagnosis of pouchitis (calprotectin: P =.5 and lactoferrin: P =.5 vs. 4 months before the diagnosis of pouchitis), although those patients were asymptomatic. In contrast, in 5 patients without pouchitis, the median fecal calprotectin and lactoferrin levels remained at low levels, and did not change significantly during the entire study (all comparisons: P >.5; Figure 2 ). Fecal biomarkers for the prediction of pouchitis The predictive value of fecal calprotectin and lactoferrin for pouchitis was evaluated. To determine optimal cutoff values for the prediction of pouchitis, we analyzed the levels of these fecal biomarkers 2 months before the diagnosis of pouchitis in the 1 patients with pouchitis and those at the end of the study (12 months after the ileostomy closure) in the 5 patients without pouchitis ( Figure 3 ). The median levels of these fecal biomarkers were significantly higher in patients with pouchitis than in those without pouchitis (calprotectin: 94 vs. 16 μ g/g, P <.1 and lactoferrin: 78 vs. 12 μ g/g, P <.1). ROC curves were drawn to investigate the sensitivity and specificity of fecal biomarkers for the prediction of pouchitis at different cutoff values ( Figure 4 ). A cutoff value of 56 μ g/g for calprotectin had a sensitivity of 1% (95% confidence interval (CI): 1 1%), a specificity of 84% (95% CI: 74 94%), a positive predictive value of 56% (95% CI: 33 79%), a negative predictive value months 8 months 6 months 4 months 2 months Diagnosis of pouchitis Before the diagnosis of pouchitis 1 months 8 months 6 months 4 months 2 months Diagnosis of pouchitis Before the diagnosis of pouchitis Figure 1. Median fecal calprotectin and lactoferrin levels before the diagnosis of pouchitis in 1 patients with pouchitis. Between 4 and 1 months before the diagnosis of pouchitis, the median fecal calprotectin and lactoferrin levels did not significantly change with time (all comparisons: P >.5), and remained at low levels. However, these levels were signifi cantly elevated 2 months before the diagnosis of pouchitis (calprotectin: P =.5 and lactoferrin: P =.5 vs. 4 months before the diagnosis of pouchitis). Boxes indicate interquartile ranges, with horizontal lines indicating medians and whiskers indicating the upper and lower limits. 215 by the American College of Gastroenterology The American Journal of GASTROENTEROLOGY

4 884 Yamamoto et al Month2 Month4 Month6 Month8 Month1 Month Month2 Month4 Month6 Month8 Month1 Month12 Figure 2. Median fecal calprotectin and lactoferrin levels during the study in 5 patients without pouchitis. The median fecal calprotectin and lactoferrin levels remained at low levels, and did not change significantly during the entire study (all comparisons: P >.5). Boxes indicate interquartile ranges, with horizontal lines indicating medians and whiskers indicating the upper and lower limits Pouchitis No pouchitis Pouchitis No pouchitis Figure 3. Fecal calprotectin and lactoferrin levels 2 months before the diagnosis of pouchitis in 1 patients with pouchitis and those at the end of the study (12 months after the ileostomy closure) in 5 patients without pouchitis. The median levels of these fecal biomarkers were signifi cantly higher in patients with pouchitis than in those without pouchitis (calprotectin: 94 vs. 16 μ g/g, P <.1 and lactoferrin: 78 vs. 12 μ g/g, P <.1). of 1% (95% CI: 1 1%), and a diagnostic accuracy of 87% (95% CI: 78 95%) to predict pouchitis. A cutoff value of 5 μ g/g for lactoferrin had a sensitivity of 9% (95% CI: 71 19%), a specificity of 86% (95% CI: 76 96%), a positive predictive value of 6% (95% CI: 35 85%), a negative predictive value of 98% (95% CI: 93 12%), and a diagnostic accuracy of 88% (95% CI: 8 96%). By combining calprotectin ( 56 μ g/g) and lactoferrin ( 5 μ g/g) levels, the sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy in predicting pouchitis were 9% (95% CI: 71 19%), 86% (95% CI: 76 96%), 56% (95% CI: 32 81%), 98% (95% CI: 93 12%), and 87% (95% CI: 78 95%), respectively. The accuracy of the test was not improved by combining calprotectin and lactoferrin levels. Correlation between pouchitis and fecal biomarkers At the time of endoscopy, the median calprotectin and lactoferrin levels were significantly higher in patients with pouchitis than in those without pouchitis (calprotectin: 112 vs. 16 μ g/g, P <.1 and lactoferrin: 95 vs. 12 μ g/g, P <.1). There was a significant positive correlation between the PDAI score and the levels of fecal biomarkers (calprotectin: r =.626, P <.1 and lactoferrin: r =.582, P <.1; Figure 5 ). Similarly, there was a significant positive correlation between the endoscopic subscore (maximum score: 6) in the PDAI and the levels of fecal biomarkers (calprotectin: r =.696, P <.1 and lactoferrin: r =.676, P <.1; Figure 6 ). Further, there was a significant positive correlation between the histologic subscore (maximum score: 6) in the PDAI and the levels of fecal biomarkers (calprotectin: r =.598, P <.1 and lactoferrin: r =.557, P <.1; Figure 7 ). However, there was no significant correlation between the symptom subscore and the levels of fecal biomarkers (calprotectin: r =.23, P =.8 and lactoferrin: r =.163, P =.21). Eight of the 1 patients with pouchitis responded to antibiotic therapy (metronidazole 75 mg/day orally for 2 weeks), in whom the median calprotectin and lactoferrin levels significantly decreased after the treatment (calprotectin: 16 to 34 μ g/g, P =.1 and lactoferrin: 89 to 31 μ g/g, P =.1). In contrast, in 2 nonresponders, the levels of these fecal biomarkers increased, and these patients subsequently required corticosteroids. Other laboratory biomarkers for the prediction of pouchitis In patients both with and without pouchitis, the median levels of laboratory biomarkers (WBC, platelet, and CRP) remained at normal levels, and did not change significantly during the entire study (all comparisons: P >.5). Fecal biomarkers vs. clinical and laboratory measurements During the study period, fecal calprotectin and lactoferrin levels showed no significant correlation with the following clinical parameters (all comparisons: P >.5): age at entry, gender, duration of UC before proctocolectomy, preoperative medications, The American Journal of GASTROENTEROLOGY VOLUME 11 JUNE 215

5 Fecal Biomarkers and Pouchitis in UC True positive rate Cutoff value False positive rate True positive rate Cutoff value False positive rate Figure 4. Receiver operating characteristic curves were drawn to investigate the sensitivity and specifi city of fecal biomarkers for the prediction of pouchitis at different cutoff values PDAI score PDAI score Figure 5. There was a signifi cant positive correlation between the Pouchitis Disease Activity Index (PDAI) score and the levels of fecal biomarkers (calprotectin: r =.626, P <.1 and lactoferrin: r =.582, P <.1) Endoscopic subscore Endoscopic subscore Figure 6. There was a signifi cant positive correlation between the endoscopic subscore in the Pouchitis Disease Activity Index (PDAI) and the levels of fecal biomarkers (calprotectin: r =.696, P <.1 and lactoferrin: r =.676, P <.1). extent of UC, and extraintestinal manifestations. Similarly, laboratory measurements including WBC, hemoglobin, platelet count, albumin, and CRP did not significantly correlate with fecal biomarkers during the study (all comparisons: P >.5). DISCUSSION Given that both fecal calprotectin and lactoferrin levels are elevated during intestinal inflammation in patients with IBD ( 7 9 ), our major interest in this study was to see whether the elevated fecal levels of these biomarkers relate to the development of pouchitis in patients after a restorative proctocolectomy for UC. A major strength of this study is that we consecutively measured the levels of these fecal biomarkers every 2 months immediately after an ileostomy closure. In the previous studies ( ), fecal calprotectin or lactoferrin level was determined using a single stool sample, and therefore the change in their levels with time was not evaluated. It is difficult to assess the predictive value of these biomarkers based on the levels determined by only one test. Other strengths of our study might include a relatively large number of patients we could include 215 by the American College of Gastroenterology The American Journal of GASTROENTEROLOGY

6 886 Yamamoto et al Histologic subscore for this study, diligent monitoring of clinical disease activity, and measurement of two biomarkers in the same test samples. We found that in patients with pouchitis both fecal calprotectin and lactoferrin levels were elevated already 2 months before the diagnosis of pouchitis, although those patients were asymptomatic. In contrast, in patients without pouchitis, these fecal biomarkers remained at low levels, and they did not change significantly during the entire study. These results suggest that fecal calprotectin and lactoferrin levels are significant predictors of pouchitis. Consecutive monitoring of these fecal biomarkers is useful for the early diagnosis of pouchitis. It seems likely that measurements of these fecal biomarkers reveal an ongoing escalating inflammatory process in the ileal pouch that gives clinical symptoms when sufficiently severe. For the prediction of pouchitis, a cutoff value of 56 μ g/g for fecal calprotectin had a sensitivity of 1% and a specificity of 84%, whereas a cutoff value of 5 μ g/g for lactoferrin had a sensitivity of 9% and a specificity of 86%. Determination and validations of biomarkers, which can identify patients at a high risk of pouchitis, should have significant appeal in clinical settings for designing strategies to prevent pouchitis by medical interventions. Although the PDAI is being commonly used in clinical studies evaluating different therapies of pouchitis, it has been suggested that the clinical components of the scores correlate poorly with endoscopic and histological findings, presumably owing to the fact that conditions other than pouchitis can result in pouch dysfunction ( 18 ). Because of the variety of etiologies that can result in pouch dysfunction, it is important that endoscopy is performed. Both calprotectin and lactoferrin are derived from polymorphonuclear neutrophils, primarily from those that infiltrate the intestinal mucosa ( 4 6 ). We found that there was a significant positive correlation between the endoscopic and histologic subscores in the PDAI and the levels of fecal biomarkers. In contrast, there was no significant correlation between the symptom subscore and the levels of fecal biomarkers. Accordingly, an elevated amount of calprotectin or lactoferrin in the stool is secondary to mucosal inflammation, so much that mucosal inflammation may be another predictor of pouchitis. Thus, fecal calprotectin and lactoferrin are highly sensitive biomarkers for detecting mucosal inflammation in the ileal pouch after restorative proctocolectomy for UC. Other laboratory biomarkers such as WBC, platelet, and CRP were not useful for the prediction and early diagnosis of pouchitis Histologic subscore Figure 7. There was a signifi cant positive correlation between the histologic subscore (maximum score: 6) in the Pouchitis Disease Activity Index (PDAI) and the levels of fecal biomarkers (calprotectin: r =.598, P <.1 and lactoferrin: r =.557, P <.1). A lack of correlation between the fecal biomarkers and symptom subscore, but a significant correlation with endoscopic and histologic subscores, would support measurement of fecal biomarkers as guidance for pre-emptive treatment (presumably antibiotics) in asymptomatic patients with elevated fecal biomarkers. We found that in patients who responded to antibiotic therapy calprotectin and lactoferrin levels significantly decreased after the treatment. In contrast, in nonresponders, the levels of these fecal biomarkers did not decrease. On the basis of these results, fecal calprotectin and lactoferrin measurements are useful for evaluating the efficacy of medications on ileal pouch inflammation, and may be helpful in the early diagnosis of recurrent pouch inflammation without an endoscopic examination. and lactoferrin are stable in the stool for several days at room temperature ( 4 6 ). They are convenient to measure at a low cost, and they may be used as a noninvasive approach to monitor mucosal inflammation ( 7 9 ) and to predict subsequent relapse ( 1 12 ) in patients with IBD. This should spare the patients from complicated endoscopic procedures. is often measured with an enzyme-linked immunosorbent assay ( 4,5 ). As enzymelinked immunosorbent assay is time-consuming and mostly suited for analyzing samples in batch, faster and more user-friendly techniques have been developed ( 19 ). In our center, the measurement of these fecal biomarkers can be performed in < 3 min. These results can immediately be applied to clinical practice. Several issues need to be addressed to provide adequate evidence supporting the clinical use of fecal biomarkers for the prediction and diagnosis of pouchitis in patients undergoing restorative proctocolectomy for UC. Integrating the time before the diagnosis of pouchitis into the analysis would be helpful. Further study is necessary to investigate the accuracies of cutoff values of fecal tests at different times (immediately at the diagnosis, 1 month and 2 months before the diagnosis, and so on) and the accuracies in symptomatic vs. asymptomatic patients. Although consecutive measurement of fecal biomarkers may be effective in a research setting, we should know how practical this is in the real world in terms of the number of samples a patient would have to provide (the incidence of pouchitis within 1 year is only 17%) and cost. We need to conduct a cost-effectiveness study to see what the optimal measurement strategy would be based on incidence of pouchitis, cost, and accuracy of the tests. In conclusion, this study showed that both fecal calprotectin and lactoferrin levels are valuable predictors of pouchitis in UC patients The American Journal of GASTROENTEROLOGY VOLUME 11 JUNE 215

7 Fecal Biomarkers and Pouchitis in UC 887 after restorative proctocolectomy. Consecutive monitoring of these fecal biomarkers is useful for the early diagnosis of pouchitis, because the levels of these fecal biomarkers are elevated before clinical symptoms are apparent. Elevated fecal calprotectin and lactoferrin levels were associated with the future development of pouchitis. To our knowledge, this is the first study that has consecutively measured calprotectin and lactoferrin levels in patients with ileal pouch after proctocolectomy for UC. Assay of fecal calprotectin and lactoferrin should serve as low-cost and noninvasive biomarkers to predict pouchitis after restorative proctocolectomy for UC. We believe that a future study should look at medical intervention to prevent pouchitis on the measurement of these fecal biomarkers. CONFLICT OF INTEREST Guarantor of the article: Takayuki Yamamoto, MD, PhD, FACG. Specific author contributions: Study design, planning and conducting the study, collection and interpretation of data, and drafting/editing the manuscript: Takayuki Yamamoto; planning the study, collection and interpretation of data, and drafting the manuscript: Takahiro Shimoyama and Takuya Bamba; editing the manuscript: Koichi Matsumoto. All the authors have approved the final draft submitted. Financial support: None. Potential competing interests: None. Study Highlights WHAT IS CURRENT KNOWLEDGE Fecal calprotectin and lactoferrin are highly sensitive and specific biomarkers for detecting intestinal inflammation in patients with inflammatory bowel disease (IBD). Elevated fecal calprotectin and lactoferrin levels are associated with subsequent clinical relapse in IBD. The value of consecutive fecal calprotectin and lactoferrin measurements for the early diagnosis and prediction of pouchitis after restorative proctocolectomy for ulcerative colitis (UC) remains unknown. WHAT IS NEW HERE In patients with pouchitis, fecal calprotectin and lactoferrin levels were elevated already 2 months before the diagnosis of pouchitis. Elevated fecal calprotectin and lactoferrin levels appeared to be significant predictors of pouchitis after restorative proctocolectomy for UC. Consecutive monitoring of these fecal biomarkers is useful for the early diagnosis of pouchitis. REFERENCES 1. Sherman J, Greenstein AJ, Greenstein AJ. Ileal j pouch complications and surgical solutions: a review. Inflamm Bowel Dis 214 ; 2 : Mahadevan U, Sandborn WJ. Diagnosis and management of pouchitis. Gastroenterology 23 ;124 : Pe n n a C, D o z oi s R, Tre m a i n e W et al. Pouchitis after ileal pouchanal anastomosis for ulcerative colitis occurs with increased frequency in patients with associated primary sclerosing cholangitis. Gut 1996 ; 38 : Tibbl e J, Te a hon K, Thjodleifsson B et al. A simple method for assessing intestinal inflammation in Crohn s disease. 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