Consecutive monitoring of faecal calprotectin during mesalazine suppository therapy for active rectal inflammation in ulcerative colitis

Transcription

1 Alimentary Pharmacology and Therapeutics Consecutive monitoring of faecal calprotectin during mesalazine suppository therapy for active rectal inflammation in ulcerative colitis T. Yamamoto, T. Shimoyama & K. Matsumoto Inflammatory Bowel Disease Centre, Yokkaichi Hazu Medical Centre, Yokkaichi, Mie, Japan. Correspondence to: Dr T. Yamamoto, Inflammatory Bowel Disease Centre, Yokkaichi Hazu Medical Centre, 1-8 Hazuyamacho, Yokkaichi, Mie 51-16, Japan. Publication data Submitted 21 April 15 First decision 28 May 15 Resubmitted 8 June 15 Accepted 16 June 15 EV Pub Online 3 July 15 This article was accepted for publication after full peer-review. SUMMARY Background No studies have monitored the levels of faecal calprotectin (FC) during mesalazine suppository therapy for proctitis in ulcerative colitis (UC). Aims To evaluate the value of consecutive monitoring of FC in patients with UC during mesalazine suppository therapy. Methods One hundred and sixty patients with active inflammation limited to the rectum were treated with mesalazine 1 g suppository once daily for 8 weeks. Patients who achieved clinical remission were advised to maintain the treatment, and were followed up for further weeks. FC levels were measured every 8 weeks during the study. Results At week 8, 118 patients (74%) went into clinical remission, of whom 88 achieved endoscopic healing. The median FC level significantly decreased in patients with clinical and endoscopic remission (both P <.1), while it did not change significantly in those without remission. Eighty (68%) of the 118 patients with remission continued the treatment. Twenty-four patients (3%) relapsed during the -week follow-up. In patients with clinical relapse, the median FC level elevated already 8 weeks before the diagnosis of relapse. In contrast, in patients who maintained remission it remained at a low level and did not significantly change during the follow-up. Elevated FC level ( 55 lg/g) was useful for the early diagnosis of relapse (88% sensitivity and % specificity). Conclusions Faecal calprotectin may represent a useful biomarker for the assessment of disease activity in UC patients treated with mesalazine suppositories. Serial monitoring of faecal calprotectin appears to be valuable for the prediction and early diagnosis of relapse during maintenance therapy. Aliment Pharmacol Ther 15; 42: doi:1.1111/apt.1338

2 T. Yamamoto et al. INTRODUCTION Ulcerative colitis (UC) is an idiopathic chronic inflammatory disease of the colon and rectum that follows a course of relapse and remission. 1, 2 The inflammation always involves the rectum and can extend proximally in a continuous fashion. The extent of UC influences the patient s management and the choice of delivery system for a given therapy. Topical therapy in the form of suppositories and enemas is often given for proctitis and left-sided colitis, respectively, but oral therapy, often combined with topical therapy is used for extensive colitis. In the European consensus guidelines on the diagnosis and management of UC, a mesalazine 1 g suppository once daily is recommended as the initial treatment for mild or moderately active proctitis. 3 For the maintenance of remission in patients with proctitis, rectal mesalazine is recommended as first-line treatment. The North American Research Group has published the clinical guidelines for the medical management of left-sided UC and proctitis. 4 Mesalazine suppositories are first-line therapy for active proctitis. Patients who initially respond to rectal mesalazine therapy usually require maintenance treatment. Patients who respond to 1 month of daily mesalazine suppository treatment may taper to every-other-day dosing and maintain response. 4 Nevertheless, in clinical practice only few patients continue topical mesalazine for a long period to avoid a flare of UC if they are in complete remission. Calprotectin is a calcium-binding heterodimer, which is abundant in the cytoplasm of neutrophils. 5, 6 Inflammation causes neutrophil activation, which results in calprotectin release proportionate to the degree of inflammation. Calprotectin can be detected using simple and cheap techniques, and it has excellent stability in faces for up to 7 days. 5 7 Several studies reported that there was a close correlation between the severity of endoscopic inflammation and faecal calprotectin (FC) levels in patients with inflammatory bowel disease (IBD) FC has been proposed as a non-invasive surrogate marker of intestinal inflammation in IBD. Therefore, measuring FC levels is a useful screening tool for identifying patients who are most likely to need endoscopy during treatment and for determining treatment response or failure in patients who are initiated on new therapy. Further, several studies found that FC levels were useful for the prediction of the clinical course in patients with IBD. 8, In a meta-analysis, the pooled sensitivity and specificity of FC to predict relapse in quiescent UC was 77% [95% confidence interval (CI): 67 85%] and 71% (95% CI: 64 77%) respectively. 16 To our knowledge, there have been no studies monitoring the levels of FC during mesalazine suppository therapy for proctitis in UC. This prospective study was conducted to evaluate the value of consecutive monitoring of FC during mesalazine suppository therapy for rectal inflammation in patients with UC. The relationship between clinical and endoscopic disease activities, and the levels of FC was evaluated. Further, in patients who achieved clinical remission the usefulness of FC in predicting relapse during maintenance treatment was investigated. PATIENTS AND METHODS Study design and endpoints This was a prospective, single-centre study undertaken at the Yokkaichi Hazu Medical Centre. The study was conducted in accordance with good clinical practice and the Declaration of Helsinki. Our study protocol was reviewed and approved by our Institutional Review Board. In this study, we initially assessed the efficacy and safety of mesalazine suppositories as induction and maintenance therapy for rectal inflammation in patients with UC. Our major purpose was to evaluate the value of consecutive monitoring of FC during mesalazine suppository therapy. The relationship between clinical and endoscopic disease activities, and the levels of FC during the treatment was evaluated. Further, the predictability of subsequent relapse by FC measurements during maintenance treatment was investigated. Patients Inclusion criteria were: (i) age between 18 and 75; (ii) endoscopic and histological diagnosis of UC; (iii) the severity of the current exacerbation was mildly or moderately active UC (3 UC disease activity index [UC-DAI] score 17 9); (iv) obvious blood in the stool (rectal bleeding score in the UC-DAI 2) at entry; (v) active endoscopic inflammation (mucosal appearance score in the UC-DAI 1) limited to the rectum (within cm from the anal verge) at entry; (vi) the time between the start of the current exacerbation and entry to this study was 4 weeks; and (vii) agreed to have endoscopic examinations during the study period. Both patients with newly diagnosed UC and those with relapsing UC were included. The clinical and endoscopic disease activities were assessed according to the UC-DAI 55 Aliment Pharmacol Ther 15; 42:

3 Mesalazine suppository for UC scores described by Sutherland et al. 17 The UC-DAI is a 12-point scoring system which includes stool frequency, rectal bleeding, mucosal appearance and physician s overall assessment of disease activity. In this study, mildly active disease was defined as 3 UC-DAI 5, and moderately active disease as 6 UC-DAI 9. Exclusion criteria were: (i) patients who had received salazosulfapyridine suppository, mesalazine enema (oral, intravenous, intramuscular or rectal) corticosteroids, immunosuppressants (including tacrolimus, azathioprine, mercaptopurine) or tumour necrosis factor (TNF)-a blocking agents for the current exacerbation; (ii) had received nonsteroidal anti-inflammatory drugs, anti-diarrhoeal (loperamide or codeine) or anti-spasmodic medications prior to entry; and (iii) active endoscopic inflammation in the colon above the rectum at entry. A total of 293 patients with active UC were screened for eligibility. Patients were excluded on the basis of exclusion criteria. Seventy-five patients were initially excluded because they had colitis extending above the rectum; 11 patients were then excluded because their rectal bleeding score was 1; 3 patients were then excluded because their current exacerbation was severe active UC (UC-DAI score 1); 19 patients were then excluded because they had received salazosulfapyridine suppository, mesalazine enema or corticosteroids for the current exacerbation; and 5 patients were finally excluded because they did not agree to have endoscopic examinations during the study period. Consequently, 1 patients who met the inclusion criteria were included in this study. Treatment Patients were treated with mesalazine 1 g suppository (Pentasa suppository; Kyorin Pharmaceutical, Tokyo, Japan) once daily for 8 week as induction therapy. Patients who achieved clinical remission at week 8 were advised to continue the treatment with mesalazine suppository as maintenance therapy, and they were followed up for further weeks. For patients who did not achieve clinical remission at week 8, additional treatment including corticosteroids, immunosuppressants or TNF-a blocking agent was started. During the study period, patients who had received oral salazosulfapyridine or mesalazine before the current exacerbation were allowed to continue the treatment at the same dosage and frequency. Salazosulfapyridine suppository, mesalazine enema, or corticosteroid enema or suppository was not given during this study. Corticosteroids, immunosuppressants or TNF-a blocking agents were not given unless patients developed severely worsening symptoms. Drugs that might interfere with the evaluation of the study medication, such as nonsteroidal anti-inflammatory drugs, anti-diarrhoeal or anti-spasmodic medications were not allowed during the study. Assessment of treatment safety and efficacy All patients were advised to record their symptoms in a diary every day. They were reviewed regularly (every 8 weeks) in our IBD clinic during the study period. At the clinic visits, patient s compliance with study medication, adverse effects, general well-being, stool frequency, stool consistency and presence or absence of abdominal pain, tenderness, tenesmus, rectal bleeding and mucus in stool were recorded. Peripheral blood samples were collected for measurements of white cell count (WBC), haemoglobin (Hb), 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. The clinical disease activity including stool frequency and rectal bleeding were assessed according to the clinical section in the UC-DAI score. To assess the clinical efficacy of the treatment, scores of stool frequency and rectal bleeding were compared at entry and at week 8. The clinical scores were determined based on the notes in the symptom diary during the previous 3 days at the time of assessment. In this study, clinical remission was defined as a score of in the clinical section (both stool frequency and rectal bleeding). In contrast, clinical improvement was defined as a decrease in the clinical section (stool frequency and/or rectal bleeding). During maintenance therapy, relapse was defined as obvious blood in the stool (rectal bleeding score 2) with active endoscopic inflammation (mucosal appearance score in the UC-DAI 1) in the rectum. When patients had clinical symptoms suggestive of relapse at the clinic visits, endoscopic examination was immediately undertaken. Endoscopic assessment At entry, endoscopic evaluation was performed for identifying the affected segment and for evaluating the severity of mucosal inflammation in all patients. At week 8, repeat endoscopic examination was done for evaluating the efficacy of the treatment. Endoscopic score was according to the mucosal appearance section in the UC- DAI. To assess the endoscopic efficacy of the treatment, endoscopic severity of the rectal inflammation was compared at entry and week 8. Endoscopic improvement Aliment Pharmacol Ther 15; 42:

4 T. Yamamoto et al. was defined as a decrease in the endoscopic score during the treatment, and endoscopic healing as score after the treatment. An endoscopist was blinded to the results of FC measurement. Measurement of faecal calprotectin Faecal calprotectin measurement was performed at clinical visits, every 8 weeks during the treatment with mesalazine suppositories. Patients were advised to collect a stool sample within 5 days before their clinic visits and store it at room temperature. At the clinic, the sample was submitted to our laboratory, and FC was measured by a quantitative enzyme immunoassay (Human Calprotectin Enzyme-linked immunosorbent assay Kit; Cell Sciences Inc., Canton, MA, USA). Laboratory investigators were blinded to the clinical data. Statistics Comparisons of frequencies were done by using the v 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 values with time was analysed by the Wilcoxon signed-rank test. Correlations were calculated by using the Spearman s r test. A value of P <.5 was considered to be statistically significant. To determine an optimal cut-off value for the prediction of relapse, a receiver operating characteristic (ROC) curve was constructed. RESULTS Patients Twenty (11%) of the 1 eligible patients ceased the suppository treatment during induction therapy, and dropped out of the study. Eventually, 1 patients were treated with mesalazine 1 g suppository once daily for 8 weeks. Baseline characteristics of the 1 patients are presented in Table 1. Efficacy of induction treatment At week 8, the rectal bleeding score had improved in 141 patients (88%) and unchanged in 19 (12%). The stool frequency score had improved in 83 patients (52%), and unchanged or deteriorated in 77 (48%). Overall, 118 (74%) went into clinical remission (normal stool frequency and no rectal bleeding), 23 patients (14%) achieved clinical improvement without remission and 19 patients (12%) did not respond. At week 8, 118 patients (74%) showed endoscopic improvement including 88 Table 1 Baseline characteristics of 1 patients Median (range) age at entry 35 (18 74) years Male: female (n) 94: 66 Disease pattern (n) Newly diagnosed UC 25 (16%) Relapsing UC 135 (84%) Concomitant medications (n) Oral mesalazine 9 (56%) Oral salazosulfapyridine 16 (1%) Extent of UC (n) Proctitis 43 (27%) Proctosigmoiditis 5 (31%) Left-sided colitis (25%) Extensive colitis* 27 (17%) Clinical disease activity (n) Mild (3 UC-DAI 5) 94 (59%) Moderate (6 UC-DAI 9) 66 (41%) Endoscopic severity of rectal inflammation (n) Mild (Mucosal appearance score 1) 64 (%) Moderate (Score 2) 94 (59%) Severe (Score 3) 2 (1%) * Involvement extends proximal to the splenic flexure. (55%) with endoscopic healing (score ). All patients with endoscopic remission achieved clinical remission. None of the following baseline factors significantly affected the incidence of clinical or endoscopic remission: age (<35/ 35 years), gender, disease pattern (newly diagnosed/relapsing UC), extent of UC (proctitis/proctosigmoiditis/left-sided colitis/extensive colitis), clinical disease activity (mild/moderate) and endoscopic activity of rectal inflammation (mild/moderate/severe). The changes in the routine laboratory measurements including WBC, Hb, platelet, albumin and CRP did not significantly correlate with the clinical or endoscopic efficacies (all comparisons: P >.5). Efficacy of maintenance treatment Eighty (68%) of the 118 patients with remission continued the treatment (3 with decreased frequency of suppository administration). Twenty-four (3%) of the patients relapsed during the -week follow-up. The endoscopic severity at the diagnostic of relapse was moderate (score 2) in 18 patients and severe (score 3) in 6 patients. The relapse was diagnosed at 8 weeks after the start of maintenance therapy in five patients, at 16 weeks in five patients, at 24 weeks in six patients, at 32 weeks in five patients and at weeks in three patients. In contrast, (53%) of 38 patients who ceased the treatment relapsed during the weeks. The relapse rate was significantly higher in patients who ceased the suppository treatment as compared with those who continued the 552 Aliment Pharmacol Ther 15; 42:

5 Mesalazine suppository for UC treatment (P =.3). Eleven (22%) of 5 patients with once daily administration and 13 (43%) of the 3 patients with decreased frequency of administration relapsed (P =.8). In patients who achieved endoscopic healing of rectal inflammation at week 8, the relapse rate was 22% (13 of 58 patients), which was significantly lower than 5% (11 of 22 patients) in patients who did not achieve endoscopic healing (P =.3). None of the following factors significantly affected the incidence of relapse: age, gender, disease pattern and extent of UC. Laboratory measurements including WBC, Hb, platelet, albumin and CRP during the study did not significantly correlate with relapse (all comparisons: P >.5). Safety and adverse events A total of 18 patients (11%) experienced adverse events during the study period: anorectal pain or discomfort in 14 patients (9%), mild headache in 2 (1%) and low fever in 2 (1%). We investigated reasons for non-adherence to mesalazine suppository in the 38 patients who ceased the suppository treatment: complete remission (unable to see the need for treatment) in patients, laziness or forgetfulness in 1, intolerable anorectal pain or discomfort in 6, economic situation in 1 and unknown in 1. Faecal calprotectin and disease activity Overall, the median (range) FC level significantly decreased [21 (1 1) lg/g at entry vs. 13 (1 131) lg/g at week 8; P =.3]. In patients with clinical remission, the median (range) FC level significantly decreased [18 (1 156) lg/g at entry vs (1 131) lg/g at week 8; P <.1], while in those without remission it did not change significantly [13 (3 1) lg/g at entry to 22.5 (1 11) lg/g at week 8; P =.93]. The endoscopic scores both at entry and at week 8 significantly correlated with the levels of FC (at entry, r =.414, P <.1; at week 8, r =.411, P <.1; Figure 1). In patients who achieved endoscopic healing (score ), the median (range) FC level significantly decreased [21 (1 156) lg/g at entry vs. 11 (1 76) lg/g at week 8; P <.1], while in those without endoscopic healing it did not change significantly [19 (2 1) lg/g at entry vs (1 131) lg/g at week 8; P =.43]. The optimal cut-off value of FC for the detection of endoscopic inflammation (mucosal appearance score in the UC-DAI 1) was determined. A cut-off value of 32 lg/g had a sensitivity of 44% (95% CI: 33 56%), a specificity of 85% (95% CI: 78 93%), a positive predict value of 71% (95% CI: 58 84%), a negative predictive value of 65% (95% CI: 57 74%) and a diagnostic accuracy of 67% (95% CI: 74%) to detect endoscopic inflammation. Faecal calprotectin for the prediction of relapse In the 24 patients who relapsed during maintenance therapy, the change in FC levels with time in each patient is presented in Figure 2. The median FC level elevated already 8 weeks before the diagnosis of relapse, although those patients were asymptomatic (Figure 3). In contrast, in 56 patients who maintained remission, the median FC level remained at a low level, and it did 225 At entry 1 Week r =.414 P <.1 r =.411 P < (n = 64) (n = 94) (n = 2) (n = 88) (n = 44) (n = 28) Endoscopic score Endoscopic score Figure 1 The endoscopic scores both at entry and at week 8 significantly correlated with the levels of FC (at entry, r =.414, P <.1; at week 8, r =.411, P <.1 by the Spearman s r test). Aliment Pharmacol Ther 15; 42:

6 T. Yamamoto et al. not significantly change during the -week follow-up (Figure 4). To determine an optimal cut-off value for the prediction of relapse, we analysed the levels of FC at 8 weeks before the diagnosis of relapse in the 24 patients who subsequently relapsed, and those at the end of the study ( weeks after the start of maintenance therapy) in the 56 patients without relapse. The median (range) level of FC was significantly higher in patients with relapse than in those without relapse [76.5 (5 111) vs (5 119) lg/g, P <.1]. The ROC curve was drawn to investigate sensitivity and specificity of FC for the prediction of relapse at different cut-off values (Fig- (a) 1 Relapse Start 8 week (c) 1 Relapse (b) 1 (d) 1 Relapse Start 8 week 16 week Relapse Start 8 week 16 week 24 week Start 8 week 16 week 24 week 32 week (e) 1 Relapse Start 8 week 16 week 24 week 32 week week At the diagnosis of relapse At 8 weeks before the diagnosis of relapse Figure 2 The change in FC levels with time in patients who were diagnosed with relapse at 8 weeks (n = 5; a), at 16 weeks (n = 5; b), at 24 weeks (n = 7; c), at 32 weeks (n = 4; d) and at weeks (n = 3; e) after the start of maintenance therapy. In the majority of patients, FC levels elevated already 8 weeks before the diagnosis of relapse. 554 Aliment Pharmacol Ther 15; 42:

7 Mesalazine suppository for UC ure 5). Elevated FC level ( 55 lg/g) was useful for the early diagnosis of clinical relapse with a sensitivity of 88% (95% CI: 74 11%), a specificity of % (95% CI: 7 91%), a positive predict value of 66% (95% CI: 49 82%), a negative predictive value of 94% (95% CI: 87 11%) and a diagnostic accuracy of 83% (95% CI: 74 91%). Faecal calprotectin vs. clinical and laboratory parameters During the study period, FC level showed no significant correlation with the following clinical parameters (all comparisons: P >.5): age, gender, disease pattern and extent of UC. Laboratory measurements including WBC, Hb, platelet, albumin and CRP did not significantly correlate with FC level during the study (all comparisons: P >.5). DISCUSSION In our study with mesalazine suppositories for rectal inflammation in UC, 74% of patients went into clinical remission and 55% achieved endoscopic healing at week 8. Sixty-eight per cent of the patients who achieved clinical remission continued the suppository treatment, of whom 7% maintained remission during the -week 1 P =.2 week 32 week 24 week16 week 8 weekdiagnosis of relapse before the diagnosis of relapse (n = 3) (n = 7) (n = 14) (n = 19) (n = 24) (n = 24) Figure 3 The change in the median FC levels during the maintenance therapy in 24 patients who relapsed. The median level elevated already 8 weeks before the diagnosis of relapse (at 8 weeks vs. 16 weeks before the diagnosis of relapse; P =.2 by the Wilcoxon signed-rank test), although those patients were asymptomatic. Boxes indicate interquartile ranges, with horizontal lines indicating medians and whiskers indicating the upper and lower limits. 1 Start 8 week 16 week 24 week 32 week week (n = 56) (n = 56) (n = 56) (n = 56) (n = 56) (n = 56) Figure 4 The change in the median FC levels during the maintenance therapy in 56 patients who maintained remission. The median level remained at a low level, and it did not change significantly during the entire study (all comparisons; P >.5 by the Wilcoxon signed-rank test). Boxes indicate interquartile ranges, with horizontal lines indicating medians and whiskers indicating the upper and lower limits. follow-up. The remission rate was significantly higher in patients who continued the treatment as compared with those who ceased the treatment. These efficacies of mesalazine suppositories as induction and maintenance therapy are consistent with those reported in the previous studies. 18, 19 We searched for factors affecting the clinical and endoscopic efficacies during induction therapy. However, none of the following factors significantly affected the remission rates: age, gender, disease pattern, extent of UC, and clinical and endoscopic disease activity at entry. These results indicate that it is not possible to predict the efficacy of mesalazine suppositories by the assessment of baseline clinical parameters. This is the first study to monitor the levels of FC during mesalazine suppository therapy for proctitis in UC. The advantages of our study are that a very homogeneous group of patients with active inflammation limited to the rectum has been studied. Furthermore, all patients underwent endoscopy to correlate FC levels with rectal inflammation, and repeated FC measurements have been performed at scheduled time points. We found that FC levels in our patients were lower than those in the previous studies In this study, we included only patients with endoscopic inflammation limited to the rectum. Further, % of our patients had mild endoscopic disease at entry. In contrast, in the previous studies patients with Aliment Pharmacol Ther 15; 42:

8 T. Yamamoto et al. True positive rate Cutoff = 55 µg/g Sensitivity 88% Specificity % False positive rate Figure 5 The ROC curve showing the true-positive rate (sensitivity) and false-positive rate (1 specificity) for the prediction of relapse at different cut-off values. Elevated FC level ( 55 lg/g) was useful for the early diagnosis of clinical relapse with a sensitivity of 88% (95% CI: 74 11%), a specificity of % (95% CI: 7 91%) and a diagnostic accuracy of 83% (95% CI: 74 91%). more extensive and severe colitis were included. To our knowledge, there have been no studies which compared FC levels between patients with proctitis and more extensive colitis. Further research is necessary on this subject. In our study, the median FC level significantly decreased in patients with clinical and endoscopic remission, whereas it did not change significantly in those without remission. Further, the endoscopic activity before and after treatment significantly correlated with the levels of FC. In contrast, the changes in laboratory parameters such as WBC, Hb, platelet, albumin and CRP did not significantly correlate with the efficacy. These results suggest that FC more accurately reflects disease activity of proctitis than the routine laboratory parameters. The significant correlation with endoscopic disease activity suggests that FC represents a valuable biomarker for monitoring disease activity in UC patients treated with mesalazine suppositories. Nonetheless, in this study, the accuracy and reliability of FC ( 32 lg/g) for the detection of endoscopic inflammation in the rectum were not favourable (44% sensitivity and 67% accuracy). These unfavourable results may be due to the fact that % of our patients had mild endoscopic disease at entry, in whom FC levels were not highly elevated. Although further research is needed, the value of FC measurement may be limited in UC patients with mild rectal inflammation. Previous studies reported that FC levels were useful for the prediction of subsequent clinical relapse in patients with IBD. 8, In these studies, FC level was determined by only one test using a single stool sample. To date, only a few studies have consecutively measured the levels of FC in IBD patients. The value of consecutive FC measurements in IBD has not been fully elucidated. In the present study, we consecutively (every 8 weeks) measured the levels of FC during maintenance therapy with mesalazine suppositories. In patients who relapsed, the median FC level elevated already 8 weeks before the diagnosis of relapse, although they were asymptomatic. In contrast, in patients who maintained remission the median FC level remained at a low level and it did not significantly change during the study period. FC level ( 55 lg/g) was useful for the prediction of clinical relapse (within the next 8 weeks) with 88% sensitivity, % specificity and 83% accuracy. Consecutive monitoring can detect the changes in FC levels instantly and accurately. These results may suggest that consecutive FC monitoring is more useful than a single measurement for the early diagnosis of relapse in IBD. Nevertheless, an interval for FC tests in our study (8 weeks) is imposed by the study design, and so it is not clear whether FC levels elevate earlier than 8 weeks before the diagnosis of relapse. This is a limitation of this study. Whether reducing the interval for measuring FC levels can improve the accuracy to predict future relapse warrants further investigation. One might argue that our cut-off value of FC (55 lg/ g) for the prediction of relapse during the remission period is higher than the median FC level (21 lg/g) at entry in patients with active disease. As mentioned before, % of our patients had mild endoscopic disease at entry. In contrast, the endoscopic severity at the diagnosis of relapse was moderate or severe. None of our relapsed patients had mild endoscopic disease. These endoscopic findings may have affected the levels of FC. FC may not be able to sharply detect mild endoscopic inflammation limited to the rectum. Large scale studies are necessary to confirm the optimal cut-off value for the prediction of relapse in patients with UC limited to the rectum. We found that the relapse rate was significantly lower in patients who achieved endoscopic healing after induction therapy than in those who did not. Endoscopic healing is therefore a valuable predictor for the 556 Aliment Pharmacol Ther 15; 42:

9 Mesalazine suppository for UC long-term clinical remission during mesalazine suppository therapy. None of the other clinical parameters including age, gender, disease pattern and extent of UC significantly affected the incidence of relapse. Similarly, systemic inflammatory markers such as WBC, platelet and CRP were not useful for the prediction of future relapse. FC is derived from polymorphonuclear neutrophils in the inflamed intestinal mucosa, and it is a highly sensitive and specific biomarker for detecting mucosal inflammation. With these findings in mind, we presume that monitoring of FC can detect an ongoing escalating inflammatory process in the rectum that gives clinical symptoms when sufficiently severe. FC appears to be convenient to measure at a low cost, and is used as a non-invasive approach to monitor intestinal inflammation and predict future relapse. This should spare patients from invasive and time-consuming endoscopic procedures. In our centre, FC can be currently measured in less than 3 minutes with new techniques; therefore the results of FC tests can be immediately applied to clinical practice. Recently, new home tests for FC are available, and they are reported to show acceptable agreement compared with the conventional measuring method in patients with UC. 21 These new tests will enable patients to manage their conditions in the home setting. For example, when the FC level is elevated in patients with proctitis, mesalazine suppositories can be given without delay at their home before the appearance of clinical symptoms. In conclusion, FC may represent a useful biomarker for the assessment of disease activity in UC patients treated with mesalazine suppositories. Further, serial monitoring of FC is useful for the prediction and early diagnosis of relapse with high sensitivity and specificity. Relapse is preceded by an increase in FC level at least 8 weeks before clinical symptoms are apparent. In contrast, sustained low FC levels predict a low risk for relapse. Blood inflammatory markers are less useful than FC for assessing the severity of intestinal inflammation in UC. Although further research is necessary, FC assay should serve as a low cost and non-invasive biomarker to assess disease activity and predict the clinical course of patients. Future studies should investigate whether early medical intervention is useful for the prevention of subsequent relapse in asymptomatic patients with elevated FC levels. AUTHORSHIP Guarantor of the article: Takayuki Yamamoto. Author contributions: Takayuki Yamamoto involved in the study design, as well as in the planning, conducting, and collection and interpretation of data for this study and in drafting/editing the manuscript. Takahiro Shimoyama involved in the planning, collection and interpretation of data for this study, and in drafting the manuscript. Koichi Matsumoto involved in editing the manuscript. All authors approved the final version of the manuscript. ACKNOWLEDGMENTS Declaration of personal and funding interests: None. REFERENCES 1. Silverberg MS, Satsangi J, Ahmad T, et al. Toward an integrated clinical, molecular and serological classification of inflammatory bowel disease: report of a Working Party of the 5 Montreal World Congress of Gastroenterology. Can J Gastroenterol 5; 19(Suppl A): 5A 36A. 2. Langholz E, Munkholm P, Davidsen M, et al. Course of ulcerative colitis: analysis of changes in disease activity over years. Gastroenterology 1994; 17: Dignass A, Lindsay JO, Sturm A, et al. Second European evidence-based consensus on the diagnosis and management of ulcerative colitis part 2: current management. J Crohns Colitis 12; 6: Regueiro M, Loftus EV Jr, Steinhart AH, et al.; Inflammatory Bowel Disease Center. Clinical guidelines for the medical management of left-sided ulcerative colitis and ulcerative proctitis: summary statement. Inflamm Bowel Dis 6; 12: Steinbakk M, Naess-Andresen CF, Lingaas E, et al. Antimicrobial actions of calcium binding leucocyte L1 protein, calprotectin. Lancet 199; 336: Sohnle PG, Collins-Lech C, Wiessner JH. Antimicrobial activity of an abundant calcium-binding protein in the cytoplasm of human neutrophils. J Infect Dis 1991; 163: Gisbert JP, McNicholl AG. Questions and answers on the role of faecal calprotectin as a biological marker in inflammatory bowel disease. Dig Liver Dis 9; 41: Tibble JA, Sigthorsson G, Bridger S, et al. Surrogate markers of intestinal inflammation are predictive of relapse in patients with inflammatory bowel disease. Gastroenterology ; 119: Canani RB, Terrin G, Rapacciuolo L, et al. Faecal calprotectin as reliable non-invasive marker to assess the severity of mucosal inflammation in children with inflammatory bowel disease. Dig Liver Dis 8; : D Haens G, Ferrante M, Vermeire S, et al. Fecal calprotectin is a surrogate marker for endoscopic lesions in Aliment Pharmacol Ther 15; 42:

10 T. Yamamoto et al. inflammatory bowel disease. Inflamm Bowel Dis 12; 18: Kopylov U, Rosenfeld G, Bressler B, et al. Clinical utility of fecal biomarkers for the diagnosis and management of inflammatory bowel disease. Inflamm Bowel Dis 14; : D Inca R, Dal Pont E, Di Leo V, et al. Can calprotectin predict relapse risk in inflammatory bowel disease? Am J Gastroenterol 8; 13: Gisbert JP, Bermejo F, Perez-Calle JL, et al. Fecal calprotectin and lactoferrin for the prediction of inflammatory bowel disease relapse. Inflamm Bowel Dis 9; 15: Lasson A, Simren M, Stotzer PO, et al. Fecal calprotectin levels predict the clinical course in patients with new onset of ulcerative colitis. Inflamm Bowel Dis 13; 19: Yamamoto T, Shiraki M, Bamba T, et al. Fecal calprotectin and lactoferrin as predictors of relapse in patients with quiescent ulcerative colitis during maintenance therapy. Int J Colorectal Dis 14; 29: Mao R, Xiao YL, Gao X, et al. Fecal calprotectin in predicting relapse of inflammatory bowel diseases: a metaanalysis of prospective studies. Inflamm Bowel Dis 12; 18: Sutherland LR, Martin F, Greer S, et al. 5-Aminosalicylic acid enema in the treatment of distal ulcerative colitis, proctosigmoiditis, and proctitis. Gastroenterology 1987; 92: Watanabe M, Nishino H, Sameshima Y, et al. Randomised clinical trial: evaluation of the efficacy of mesalazine (mesalamine) suppositories in patients with ulcerative colitis and active rectal inflammation - a placebo-controlled study. Aliment Pharmacol Ther 13; 38: D Albasio G, Paoluzi P, Campieri M, et al. Maintenance treatment of ulcerative proctitis with mesalazine suppositories: a double-blind placebocontrolled trial. The Italian IBD Study Group. Am J Gastroenterol 1998; 93: De Vos M, Louis EJ, Jahnsen J, et al. Consecutive fecal calprotectin measurements to predict relapse in patients with ulcerative colitis receiving infliximab maintenance therapy. Inflamm Bowel Dis 13; 19: Elkjaer M, Burisch J, Voxen Hansen V, et al. A new rapid home test for faecal calprotectin in ulcerative colitis. Aliment Pharmacol Ther 1; 31: Aliment Pharmacol Ther 15; 42: