Crohn's disease activity assessed by fecal calprotectin and lactoferrin: correlation with Crohn's disease activity index and endoscopic findings

Population pharmacokinetic-pharmacodynamic model-based exploration of alternative ustekinumab dosage regimens for patients with Crohn's disease

AIMS

In the UNITI endoscopy sub-study, only 17.4% of patients with Crohn's disease (CD) on ustekinumab achieved endoscopic response and 10.9% of patients achieved endoscopic remission at week (w)44. We aimed to evaluate the impact of alternative ustekinumab dosage regimens on endoscopic outcomes based on population pharmacokinetic-pharmacodynamic (popPK-PD) modelling and simulation analysis.

METHODS

Real-world data were obtained from 83 patients with moderate-to-severe CD (95% biological-refractory) enrolled in a prospective cohort study receiving intravenous ustekinumab (~6 mg/kg) followed by every eight-week (q8w) subcutaneous maintenance therapy (90 mg). Three sequential models were developed: a two-compartment popPK model linking ustekinumab dose to ustekinumab exposure, an indirect response popPK-PD model describing the effect of ustekinumab exposure on fecal calprotectin (fCal), and a logistic regression outcome model linking fCal to endoscopic outcomes.

RESULTS

Ustekinumab clearance increased with decreasing serum albumin and increasing bodyweight. fCal decreased with increasing ustekinumab exposure. The probability of endoscopic response at w24 increased from 10.0% to 17.9% with fCal at w8 decreasing from 1800 μg/g to 694 μg/g (EC₅₀ ). The probability of endoscopic remission at w24 increased from 2.1% to 10.0% with fCal at w8 decreasing from 1800 μg/g to 214 μg/g (EC₅₀ ). Simulation-based comparison of q8w and q4w maintenance dosing regimens predicted 16.7% and 22.2% endoscopic response rates, respectively. Endoscopic remission rates were estimated to be 4.2% on q8w dosing and 6.7% on q4w dosing.

CONCLUSIONS

The developed models can guide clinical trial design and support model-informed dose optimization (stratified or individualized dosing) to improve endoscopic outcomes.

Blood-based prognostic biomarkers in Crohn's Disease patients on biologics: a promising tool to predict endoscopic outcomes

OBJECTIVE

There is a growing need for biomarkers to predict therapeutic outcome in Crohn's disease (CD).

MAIN OUTCOME MEASURES

The aim was to evaluate whether NLR (neutrophil-to-lymphocyte ratio), PLR (platelet-to-lymphocyte ratio), ELR (eosinophil-to-lymphocyte ratio), and ENLR (eosinophil*neutrophil-to-lymphocyte ratio), could be prognostic biomarkers of endoscopic response (ER) when starting biologics.

RESEARCH DESIGN AND METHODS

Patients with CD who started biologics were enrolled. Multivariate analysis was used to evaluate whether NLR, PLR, ELR and ENLR at baseline and at w12 could predict ER (Simple Endoscopic Score for Crohn's disease [SES-CD] ≤2 or SES-CD≤2 and Rutgeerts i0-i1) after 52 weeks of treatment. Area under the curve (AUC) was calculated to find the cutoffs.

RESULTS

107 patients were included. Patients who achieved ER had significantly lower baseline NLR (p = 0.025), ELR (p = 0.013), and ENLR (p = 0.020) compared with those without ER; results after 12 weeks of treatment for ELR (p = 0.006) and ENLR (p = 0.003). AUC was 0.64 (p = 0.003), 0.67 (p = 0.006) and 0.65 (p = 0.014) for NLR, ELR and ENLR.

CONCLUSIONS

Low NLR, ELR and ENLR can predict ER and could be used in clinical practice for a better management of CD patients.

Fecal Calprotectin May Predict Adverse Pregnancy-Related Outcomes in Patients with Inflammatory Bowel Disease

BACKGROUND

The role of fecal calprotectin in predicting pregnancy-related outcomes in inflammatory bowel disease (IBD) remains unknown.

AIM

To determine whether increased fecal calprotectin during pregnancy is associated with adverse pregnancy outcomes in IBD.

METHODS

This is a multicenter cohort study of women with IBD who underwent fecal calprotectin monitoring during pregnancy. Fecal calprotectin levels were stratified by trimester, and adverse pregnancy-related outcomes were recorded. The Mann-Whitney U test assessed differences between continuous variables, whereas categorical variables were compared using the Chi-squared test.

RESULTS

Eighty-five women with IBD were included. First trimester fecal calprotectin was higher in patients who underwent emergency Cesarean birth compared to those who had a vaginal delivery (503 ug/g, IQR 1554.3 ug/g vs. 130 ug/g, IQR 482 ug/g, p = .030, respectively) and in those who delivered infants with low birth weight compared to normal birth weight (1511 ug/g, IQR 579 ug/g vs. 168 ug/g, IQR 413 ug/g, p = .049, respectively). Third trimester fecal calprotectin was higher in those with non-elective induction of labor (334.5 ug/g, IQR 1411.0 ug/g) compared to those with spontaneous delivery (116.5 ug/g, IQR 227.1 ug/g) (p = .025). Those with a fecal calprotectin ≥ 250 ug/g in the second trimester had an increased incidence of infants with low birth weight (35.3% vs. 3.8%) (p = .049), whereas those with a fecal calprotectin ≥ 250 ug/g in the third trimester had an increased incidence of non-elective induction of labor (43.8% vs. 10.3%, p = .030).

CONCLUSIONS

Fecal calprotectin may be a useful noninvasive marker to predict adverse pregnancy-related outcomes in patients with IBD.

C-reactive protein/abumin ratio is a useful biomarker for predicting the mucosal healing in the Crohn disease: A retrospective study

Ileocolonoscopy is currently recognized as the gold standard for evaluating mucosal healing in patients with Crohn disease (CD). However, the ideal noninvasive marker to assess mucosal healing instead of invasive ileocolonoscopy is not available. This study aimed to determine the correlations between the mucosal healing and serological optimizing markers in CD.This retrospective study consecutively included 62 CD patients with 137 hospitalizations between March 2014 and March 2020. On the basis of the Simple Endoscopic Score for Crohn's disease (SES-CD), the CD patients were divided into mucosal healing group (SES-CD ≤ 2) and nonmucosal healing group (SES-CD > 2). We collected the results of ileocolonoscopy examination and inflammatory markers and then serological optimizing markers, including C-reactive protein/albumin ratio (CRP/ALB), platelet/albumin ratio (PLT/ALB), neutrophil-lymphocyte ratio (NLR), and platelet-lymphocyte ratio (PLR) were calculated. The control group consisted of 50 healthy volunteers in the corresponding period.We found that CRP/ALB, PLT/ALB, NLR, and PLR were correlated with the mucosal healing of CD, and the correlation of CRP/ALB with the mucosal healing was the highest (r = -0.64). Receiver operating characteristic (ROC) analysis showed that the area under the curve (AUC) of CRP/ALB (0.87) was higher than NLR (0.69), PLR (0.72), and PLT/ALB (0.81). In the efficacy of assessing the mucosal healing in CD, the sensitivity of CRP/ALB, NLR, PLR, and PLT/ALB were 91.1%, 83.9%, 73.2%, and 73.2%, respectively, and the specificity was 76.5%, 46.9%, 64.2%, and 75.3%, respectively.CRP/ALB was the most appropriate marker to assess CD mucosal healing among the serological optimizing markers.

Week 6 Calprotectin Best Predicts Likelihood of Long-term Endoscopic Healing in Crohn's Disease: A Post-hoc Analysis of the UNITI/IM-UNITI Trials

OBJECTIVES

There is need for biomarkers as predictors of outcome of medical treatment in Crohn's disease. The purpose of this study was to evaluate the predictive performance of faecal calprotectin for short- and long-term clinical and endoscopic outcomes.

METHODS

This post-hoc analysis of the UNITI/IM-UNITI studies [NCT01369329, NCT01369342, and NCT01369355; YODA #2019-4026] included 677 patients to evaluate the relationship of Week 6 calprotectin cut-offs and changes from baseline assessments in calprotectin for prediction of outcomes at Weeks 8, 32, and 52, using receiver operating characteristic curves with comparisons of areas under the curve [AUC]. The relationship between clinical and biomarker assessments at Week 6 and endoscopic remission [ER] at Week 52 was evaluated using multivariate logistic regression models adjusted for confounders.

RESULTS

A Week 6 calprotectin <250 mg/kg demonstrated a significant ability to predict Week 52 ER (AUC 0.709, 95% confidence interval [CI] 0.566-0.852, p = 0.014) with fair accuracy, and performed better than other calprotectin cut-offs and deltas from baseline for prediction of Week 52 ER. When adjusted for covariates, patients with a Week 6 faecal calprotectin <250 mg/kg had 3.48 times [95% CI 1.31-9.28, p = 0.013] increased odds of Week 52 ER. No other Week 6 clinical assessment [clinical remission or clinical response] or biomarker [CRP <5 or drug level] had an association with Week 52 ER.

CONCLUSIONS

In summary, the results of this post-hoc analysis suggest that Week 6 calprotectin levels < 250 mg/kg can be predictive of future endoscopic healing and may be more informative than clinical symptom improvement.

PODCAST

This article has an associated podcast which can be accessed at https://academic.oup.com/ecco-jcc/pages/podcast.

A Practical Guide for Faecal Calprotectin Measurement: Myths and Realities

BACKGROUND AND AIMS

Faecal calprotectin [FC] is a valid and non-invasive marker of mucosal inflammation. It is widely used both in clinical trials and in daily clinical practice for patients with inflammatory bowel diseases, but currently no accepted standardization for FC testing is available. Our primary aim here was to provide a clinician's guide containing all the practical information on FC measurement in order to avoid any confounding factors, to minimize intra- and inter-individual variability in dosage, and to ensure a better and adequate interpretation of the results.

METHODS

We conducted a detailed search of the scientific literature in the PubMed/MEDLINE, EMBASE and Cochrane databases up to January 2020 to find all relevant and available articles on pre-analytical and analytical phases of FC measurement.

RESULTS

FC testing is a multi-step procedure consisting of a pre-analytical phase aimed to collect and process the stool sample and a subsequent analytical phase of FC measurement. Several factors can influence test results determining false positives or false negatives. Importantly, this faecal marker is mostly used for patient follow-up and as a predictor of treatment response. For this reason, any altered data may affect the physicians' decisions, negatively impacting on patient management.

CONCLUSIONS

This review provides for the first time practical advice to minimize dosage variability, although further dedicated studies are needed to compare commercially available tests and identify the best tools for the most precise and accurate FC measurement.

Down-Regulation of Colonic ACE2 Expression in Patients With Inflammatory Bowel Disease Responding to Anti-TNF Therapy: Implications for COVID-19

Background and Aims: Angiotensin-converting enzyme II (ACE2) is the key molecule for understanding the pathophysiology of COVID-19. The risk of COVID-19 and impact of immunosuppressive treatment on disease course in patients with inflammatory bowel disease (IBD) remain controversial. We aimed to determine the change of intestinal ACE2 expression before and after biologics treatment including anti-tumor necrosis factor α (anti-TNFα), anti-integrin, and anti-interleukin (IL)12/23 in IBD patients. Methods: We analyzed the ACE2 expression through the public database of paired intestinal biopsies from IBD patients before and after biologic therapy. Change of ACE2 RNA and protein expression were validated in two independent cohorts (Birmingham cohort and Guangzhou cohort). The correlation between ACE2 expression and disease activity was also analyzed. Results: Mining information from the GEO database showed that compared with healthy control, intestinal ACE2 expression was downregulated in ileum of CD patients, while upregulated in colon of both CD and UC patients. Colonic ACE2 RNA expression was decreased significantly in patients responding to anti-TNFα but not anti-integrin and anti-IL12/23, which was validated in the Birmingham cohort. Using the Guangzhou cohort including 53 patients matched by pre- and post-anti-TNFα therapy, colonic ACE2 protein expression was significantly downregulated after anti-TNFα treatment in responders (P < 0.001) rather than non-responders. Colonic ACE2 expression was significantly higher in patients with severe histologically active disease compared with those with moderate (P < 0.0001) and mild (P = 0.0002) histologically active disease. Conclusion: Intestinal inflammation influences the expression of intestinal ACE2 in IBD patients, with different alterations in the ileum and colon. Colonic ACE2 expression was downregulated after anti-TNFα therapy in IBD patients responding to treatment. This might provide new clues regarding the risk of SARS-CoV-2 infection and the potential benefit of sustaining anti-TNFα treatment in patients with IBD.

Serum inflammatory markers in the diagnosis and assessment of Crohn's disease activity

INTRODUCTION

The aim of our study was to evaluate the diagnostic characteristics of selected inflammatory markers and the results of multiplication of their concentrations in the diagnosis and assessment of Crohn's disease (CD) activity.

METHODS

We studied 49 patients with CD and 31 healthy controls. The CD patients were assigned to subgroups with active and inactive disease based on the Crohn's Disease Activity Index score. Serum interleukins and C-reactive protein (CRP) were measured using immunoassays.

RESULTS

Serum CRP and interleukins: IL-6, IL-17A, IL-23 were significantly higher in the CD group than in controls, with the best diagnostic performance for IL-23. Only serum IL-6 and CRP were significantly higher in active than in inactive disease, with the better performance of CRP. Multiplication results did not perform better than individual multipliers.

CONCLUSIONS

Serum CRP may be useful in the assessment of CD activity and there is a need for introduction of IL-23 for the CD diagnosis.

Fecal calprotectin is an early predictor of endoscopic response and histologic remission after the start of vedolizumab in inflammatory bowel disease

BACKGROUND AND AIMS

Early prediction of the effect of vedolizumab (VDZ) in inflammatory bowel disease (IBD) is of paramount importance to guide clinical decisions. This study assessed whether early fecal calprotectin (FC) can predict endoscopic response and histologic remission after VDZ initiation.

METHODS

This was a prospective study. Inclusion criteria were endoscopic inflammation and FC >100 µg/g. FC was determined at baseline and weeks 2, 4, 8 and 16. At week 16, endoscopies with ileal and colonic biopsies were performed. FC changes were assessed with Wilcoxon Rank Sum tests. ROC statistics were used to assess the diagnostic accuracy of FC.

RESULTS

In total, 45 patients [27 Crohn's disease (CD), 16/2 ulcerative colitis (UC)/IBD-unclassified] [40% males, median age 39 (28-51) years] were included. Week 16 endoscopic response and histologic remission rates were 58% and 33%. A median 37% decline in FC at week 2 was observed only in endoscopic responders, p = 0.025. FC <250 µg/g at week 8 predicted endoscopic response in both UC and CD (positive predictive value 100%), whereas absence of FC decline at week 8 corresponded with absence of endoscopic response in CD [negative predictive value (NPV) 82%] and absence of histologic remission in both UC and CD (NPV 90%).

CONCLUSION

The onset of a decline in FC as early as week 2 is associated with endoscopic response to VDZ induction. FC <250 µg/g at week 8 is associated with endoscopic response, whereas absence of FC decline at week 8 is associated with absence of both endoscopic response and histologic remission. FC levels 8 weeks after the start of VDZ could be used to guide clinical decisions and might substitute for endoscopic response evaluation.

Lactoferrin and Its Derived Peptides: An Alternative for Combating Virulence Mechanisms Developed by Pathogens

Due to the emergence of multidrug-resistant pathogens, it is necessary to develop options to fight infections caused by these agents. Lactoferrin (Lf) is a cationic nonheme multifunctional glycoprotein of the innate immune system of mammals that provides numerous benefits. Lf is bacteriostatic and/or bactericidal, can stimulate cell proliferation and differentiation, facilitate iron absorption, improve neural development and cognition, promote bone growth, prevent cancer and exert anti-inflammatory and immunoregulatory effects. Lactoferrin is present in colostrum and milk and is also produced by the secondary granules of polymorphonuclear leukocytes, which store this glycoprotein and release it at sites of infection. Lf is also present in many fluids and exocrine secretions, on the surfaces of the digestive, respiratory and reproductive systems that are commonly exposed to pathogens. Apo-Lf (an iron-free molecule) can be microbiostatic due to its ability to capture ferric iron, blocking the availability of host iron to pathogens. However, apo-Lf is mostly microbicidal via its interaction with the microbial surface, causing membrane damage and altering its permeability function. Lf can inhibit viral entry by binding to cell receptors or viral particles. Lf is also able to counter different important mechanisms evolved by microbial pathogens to infect and invade the host, such as adherence, colonization, invasion, production of biofilms and production of virulence factors such as proteases and toxins. Lf can also cause mitochondrial and caspase-dependent regulated cell death and apoptosis-like in pathogenic yeasts. All of these mechanisms are important targets for treatment with Lf. Holo-Lf (the iron-saturated molecule) can contain up to two ferric ions and can also be microbicidal against some pathogens. On the other hand, lactoferricins (Lfcins) are peptides derived from the N-terminus of Lf that are produced by proteolysis with pepsin under acidic conditions, and they cause similar effects on pathogens to those caused by the parental Lf. Synthetic analog peptides comprising the N-terminus Lf region similarly exhibit potent antimicrobial properties. Importantly, there are no reported pathogens that are resistant to Lf and Lfcins; in addition, Lf and Lfcins have shown a synergistic effect with antimicrobial and antiviral drugs. Due to the Lf properties being microbiostatic, microbicidal, anti-inflammatory and an immune modulator, it represents an excellent natural alternative either alone or as adjuvant in the combat to antibiotic multidrug-resistant bacteria and other pathogens. This review aimed to evaluate the data that appeared in the literature about the effects of Lf and its derived peptides on pathogenic bacteria, protozoa, fungi and viruses and how Lf and Lfcins inhibit the mechanisms developed by these pathogens to cause disease.

Association of Serum Calprotectin Concentrations with Mortality in Critically Ill and Septic Patients

Background: Calprotectin is present in the cytosol of neutrophil granulocytes and released upon activation. Fecal calprotectin is applied in the clinical management of inflammatory bowel disease whereas serum calprotectin has been discussed as a biomarker in inflammatory disorders. However, its long-term prognostic relevance in critical illness remains unclear. Our aim was to investigate serum calprotectin concentrations as a prognostic biomarker in critically ill and septic patients. Methods: Serum calprotectin concentrations were analyzed in 165 critically ill patients (108 with sepsis, 57 without sepsis) included in our observational study. Patients were enrolled upon admission to the medical intensive care unit (ICU) of the RWTH Aachen University Hospital. Calprotectin concentrations were compared to 24 healthy controls and correlated with clinical parameters, therapeutic interventions, and survival. Results: Serum calprotectin concentrations were significantly increased in ICU patients as well as in septic patients compared to respective controls (p < 0.001 for ICU patients and p = 0.001 for septic patients). Lower calprotectin concentrations were measured in patients with comorbidities i.e., coronary artery disease. Calprotectin concentrations strongly correlated with the C-reactive protein (p < 0.001) and were closely associated to parameters of mechanical ventilation (i.a. inspiratory oxygen fraction, FiO2; p < 0.001). The overall survival was significantly impaired in septic patients with high baseline calprotectin concentrations (p = 0.036). However, patients with increasing calprotectin serum concentrations within the first week of ICU admission showed an improved overall survival (p = 0.009). Conclusions: In summary, serum calprotectin concentrations are significantly increased in critically ill patients with sepsis. High calprotectin concentrations at ICU admission predict long-term mortality risk, whereas increasing calprotectin concentrations are associated with a favorable long-term outcome.

Calprotectin in inflammatory bowel disease

The term IBD is usually used for referring to a group of inflammatory gastro-intestinal diseases (mainly Crohn's disease and ulcerative colitis). Accordingly, IBD arises as a result of inappropriate immune response to intestinal commensal organisms among genetically susceptible individuals. Performing colonoscopy and histopathologic evaluation on an inflamed bowel biopsy specimen are currently considered as gold standards for diagnosis and management of IBD. Correspondingly, these techniques are known to be invasive and costly. In recent decades, fecal calprotectin, as a biomarker, has received much attention for the diagnosis and non-invasive management of IBD. Up to now, many studies have investigated the efficacy of fecal calprotectin in the areas of IBD differentiation from IBS, prediction of endoscopic and histologic activities of IBD and prediction of disease recurrence. Although some of these studies have reported promising results, some others have shown significant limitations. Therefore, in this paper, we reviewed the most interesting ones of these studies after a brief discussion of the laboratory measurement of fecal calprotectin. Moreover, we attempted to provide an answer for the question of whether fecal-calprotectin could be considered as a potential surrogate marker for colonoscopy.

Fecal Calprotectin Is Highly Effective to Detect Endoscopic Ulcerations in Crohn's Disease Regardless of Disease Location

BACKGROUND

As the reliability of fecal calprotectin (Fcal) remains debatable to detect endoscopic ulcerations in patients with pure ileal Crohn's disease (CD), we aimed to compare its performances with those observed in patients with colonic or ileocolonic location.

METHODS

Using a prospectively maintained database, we analyzed 123 CD patients with Fcal measurement and ileocolonoscopy performed within 1 month with no therapeutic intervention during this interval. Receiver operating characterstic curves (ROC) were used to determine the best Fcal threshold to detect endoscopic ulcerations, taking into account the clinical relevance and usual recommended indices. Sensitivity, specificity, and positive (PPV) and negative predictive values (NPV) were presented with 95% confidence intervals.

RESULTS

The mean Fcal level was significantly higher in patients with endoscopic ulcerations in the L1 group (P = 0.025) and the L2-L3 group (P < 0.001). Using ROC curves, Fcal >200 µg/g and Fcal >250 µg/g were the best thresholds to detect endoscopic ulcerations in the L1 group (sensitivity = 75.0, 95% CI, 47.6-92.7; specificity = 87.5, 95% CI, 67.6-97.3; PPV = 80.0, 95% CI, 51.9-95.7; and NPV = 84.0; 95% CI, 63.9-95.5) and in the L2-L3 group (sensitivity = 84.1 95% CI, 69.9-93.4; specificity = 74.4, 95% CI, 57.9-87.0; PPV = 78.7, 95% CI, 64.3-89.3, and NPV = 80.6, 95% CI, 64.0-91.8), respectively. We compared the AUC between L1 and L2-L3 groups, and no difference was shown (0.89 vs 0.84, respectively, P = 0.46). We also compared 2-by-2 sensitivity, specificity, PPV, NPV, and accuracy and we did not observe any significant difference.

CONCLUSION

Fecal calprotectin is highly effective to detect endoscopic ulcerations regardless of CD location but requires a lower cutoff value in patients with pure ileal involvement.

Iron at the host-microbe interface

Iron is an essential micronutrient for nearly all living organisms. In addition to facilitating redox reactions, iron is bound by metalloproteins that participate in a variety of biological processes. As the bioavailability of free iron in host environments is extremely low, iron lies at the center of a battle for nutrients between microbes and their host. Mucosal surfaces such as the respiratory and gastrointestinal tracts are constantly exposed to commensal and pathogenic microorganisms. Whereas a key strategy of mammalian antimicrobial defense is to deprive microbes of iron, pathogens and some commensals have evolved effective strategies to circumvent iron limitation. Here we provide an overview of mechanisms underpinning the tug-of-war for iron between microbes and their host, with a particular focus on mucosal surfaces.

Association of Biomarker Cutoffs and Endoscopic Outcomes in Crohn's Disease: A Post Hoc Analysis From the CALM Study

BACKGROUND

CALM was a randomized phase 3 trial in patients with Crohn's disease (CD) that demonstrated improved endoscopic outcomes when treatment was escalated based on cutoffs for inflammatory biomarkers, fecal calprotectin (FC), C-reactive protein (CRP), and CD Activity Index (CDAI) remission vs CDAI response alone. The purpose of this post hoc analysis of CALM was to identify drivers of treatment escalation and evaluate the association between biomarker cutoff concentrations and endoscopic end points.

METHODS

The proportion of patients achieving CD Endoscopic Index of Severity (CDEIS) <4 and no deep ulcers 48 weeks after randomization was evaluated according to CRP <5 mg/L or ≥5 mg/L and FC <250 μg/g or ≥250 μg/g. Subgroup analyses were performed according to disease location, and sensitivity analyses were conducted in patients with elevated CRP and/or FC at baseline. The association between endoscopic end points and biomarker cutoffs was performed using χ 2 test.

RESULTS

The proportion of patients who achieved the primary end point CDEIS <4 and no deep ulcers was significantly greater for those with FC <250 µg/g (74%; P < 0.001), with an additive effect for CRP <5 mg/L. The association of FC <250 µg/g with improved endoscopic outcomes was independent of disease location, although the greatest association was observed for ileocolonic disease. Fecal calprotectin <250 µg/g, CRP <5 mg/L, and CDAI <150 gave a sensitivity/specificity of 72%/63% and positive/negative predictive values of 86%/42% for CDEIS <4 and no deep ulcers 48 weeks after randomization.

CONCLUSION

This post hoc analysis of CALM demonstrated that a cutoff of FC <250 µg/g is a useful surrogate marker for mucosal healing in CD.

The use of serum calprotectin as a biomarker for inflammatory activity in inflammatory bowel disease

INTRODUCTION

simple, reliable and non-invasive biomarkers are needed to enable the early detection of inflammatory activity for the correct management of inflammatory bowel disease (IBD). One of these biomarkers may be serum calprotectin (SC).

MATERIAL AND METHODS

a prospective study was performed of patients with IBD due to undergo a colonoscopy as part of the common clinical practice. The study parameters included SC, fecal calprotectin (FC) and conventional blood test parameters. Clinical indices (Harvey and Walmsley) and relevant endoscopic scores were completed for each scenario (Simple Endoscopic Score Crohn Disease [SES-CD] and Mayo).

RESULTS

fifty-three patients were included in the study, 51% (27 patients) with ulcerative colitis (UC) and 49% (26 patients) with Crohn's disease (CD). The CS values in UC were significantly higher with an endoscopic Mayo score 2/3 (median score 10.39 mg/ml [IQR: 7.4-12.2]) compared to those with a Mayo score of 0/1 (median 4.07 mg/ml [IQR: 2.9-7.2]) (p = 0.01). The area under the ROC curve (AUCROC) was 0.85 and the sensitivity and specificity were 83.3% and 81.25%, respectively, for a SC cut-off point of 4.4 mg/dl. Furthermore, a higher AUCROC was obtained in comparison with other serological markers for activity (C-reactive protein [CRP], erythrocyte sedimentation rate [ESR], hemoglobin [Hb] and platelets). There were no statistically significant differences in the comparison between SC and endoscopic findings in CD (SES CD > 3: 20.1 [IQR: 16.8-23.4] vs SESC ≤ 3:6.25 [IQR: 5.4-7.1]) (p = 0.8).

CONCLUSIONS

SC is a good indirect marker of inflammatory activity and there was a correlation with endoscopic findings in UC. However, there were no statistically significant differences in the case of CD.

Fecal calprotectin: current and future perspectives for inflammatory bowel disease treatment

Fecal calprotectin has been widely studied in inflammatory bowel disease (IBD) under clinical and therapeutic settings. It showed a good correlation with clinical, endoscopic, and histologic findings. For these reasons, fecal calprotectin is currently one of the most useful tools in IBD care, both in diagnosis and in clinical management. The development of biologic drugs allowed a deeper control of disease, which sometimes reaches histological healing; this is associated with a reduced risk of relapses and complications. The management of IBD treatment is currently carried out with a treat-to-target approach, and mucosal healing is considered at present to be the optimal therapeutic target, but the future is going through histologic remission. Fecal calprotectin is probably the best marker of mucosal healing, but it is correlated also with histologic remission: moreover, it has been recently studied as a possible therapeutic target in the CALM study. We carried out a comprehensive literature review in order to evaluate the role of fecal calprotectin at present and in the future in the management of IBD therapies.

Ileal and Rectal Ulcer Size Affects the Ability to Achieve Endoscopic Remission: A Post hoc Analysis of the SONIC Trial

INTRODUCTION

It is unclear how baseline endoscopic characteristics in Crohn's disease (CD) affect the ability to achieve endoscopic remission (ER). We aimed to determine the endoscopic prognostic factors that influence achieving ER in CD.

DESIGN

This post hoc analysis of SONIC (NCT00094458; YODA #2019-3980) evaluated baseline and week 26 endoscopy indices in 172 patients using the CD Endoscopic Index of Severity (CDEIS) and the Simple Endoscopic Score for CD. The impact of baseline ulcer depth and size on achieving week 26 ER was assessed using multivariate logistic regression models adjusted for confounders.

RESULTS

The ER rate of ileal ulcers was significantly lower than ER rates throughout the colon (P < 0.0001). Ileal ulcers >2 cm were less likely to achieve ER compared with smaller ulcers {odds ratio (OR) 0.31 (95% confidence interval [CI] 0.11-0.89), P = 0.03}. Similarly, rectal ulcers >2 cm were associated with reduced odds of week 26 ER (OR 0.26 [95% CI 0.08-0.80], P = 0.02). Ulcer size in other colonic segments did not affect the achievement of week 26 ER. Deep ileal and rectal ulcers >2 cm compared with smaller or superficial ulcers were even less likely to achieve week 26 ER (ileum: OR 0.10, 95% CI 0.02-0.68, P = 0.02; rectum: OR 0.12, 0.02-0.82, P = 0.03). High baseline Simple Endoscopic Score for CD (≥16) or CDEIS scores (≥12) did not affect achieving week 26 ER.

DISCUSSION

Patients with larger and deep ulcers in the ileum or rectum may have difficulty achieving ER. Overall degree of endoscopic inflammation as measured numerically by endoscopic scores does not affect the likelihood of achieving week 26 ER.

Fecal calprotectin in the pediatric population: a 2020 update

Calprotectin is a calcium and zinc-binding protein, formed by a hetero complex of S100A8 and S100A9 proteins, which belong to the S-100 protein family consisting in more than 20 different proteins with a tissue-specific expression pattern. This protein is secreted extracellularly from stimulated neutrophils or released by cell disruption or death. The presence of calprotectin in feces quantitatively relates to neutrophil migration toward the gastrointestinal (GI) tract; thus, it represents a useful marker of intestinal inflammation. Fecal calprotectin (FC) has been proven largely useful for determining the inflammatory origin of GI symptoms differentiating between organic and non-organic diseases. Indeed, increased FC levels are also seen in gastroenteritis, microscopic colitis, polyps, malignancies and cystic fibrosis. To date, there are many evidences regarding usefulness in the detection of fecal calprotectin for the management of gastrointestinal disorders, both in children and adults but, especially in the pediatric population, still clear indications for its use are lacking. Its incorporation in primary care reduces the risk of missing an organic disease and facilitates the indication for expensive and invasive investigations as colonoscopy. We herein review and discuss the last evidence on the usefulness of FC in children, with its current indications and future prospective.

Evaluation of Changes in Gut Microbiota in Patients with Crohn's Disease after Anti-Tnfα Treatment: Prospective Multicenter Observational Study

Background: Crohn's disease is believed to result from the interaction between genetic susceptibility, environmental factors and gut microbiota, leading to an aberrant immune response. The objectives of this study are to evaluate the qualitative and quantitative changes in the microbiota of patients with Crohn's disease after six months of anti-tumor-necrosis factor (anti-TNFα) (infliximab or adalimumab) treatment and to determine whether these changes lead to the recovery of normal microbiota when compared to a control group of healthy subjects. In addition, we will evaluate the potential role of the Faecalibacterium prausnitzii/Escherichia coli and Faecalibacterium prausnitzii/Clostridium coccoides ratios as indicators of therapeutic response to anti-TNFα drugs. Methods/Design: This prospective multicenter observational study will comprise a total of 88 subjects: 44 patients with Crohn's disease scheduled to start anti-TNFα treatment as described in the drug specifications to control the disease and 44 healthy individuals who share the same lifestyle and eating habits. The presence of inflammatory activity will be determined by the Harvey-Bradshaw index, analytical parameters in blood, including C-reactive protein, and fecal calprotectin levels at commencement of the study, at three months and at six months, allowing the classification of patients into responders and non-responders. Microbiota composition and the quantitative relationship between Faecalibacterium prausnitzii and Escherichia coli and between Faecalibacterium prausnitzii and Clostridium coccoidesgroup as indicators of dysbiosis will be studied at inclusion and six months after initiation of treatment using ultra sequencing with Illumina technology and comparative bioinformatics analysis for the former relationship, and digital droplet PCR using stool samples for the latter. Upon inclusion, patients will complete a survey of dietary intake for the three days prior to stool collection, which will be repeated six months later in a second collection to minimize dietary bias. Discussion: In this study, massive sequencing, a reliable new tool, will be applied to identify early biomarkers of response to anti-TNF treatment in patients with Crohn's disease to improve clinical management of these patients, reduce morbidity rates and improve efficiency.

The New Proactive Approach and Precision Medicine in Crohn's Disease

The proactive approach to Crohn's disease (CD) management advocates moving toward algorithmic tight-control scenarios that are designed for each CD phenotype to guide remission induction, maintenance therapy, active monitoring, and multidisciplinary care to manage the complexities of each inflammatory bowel disease (IBD) patient. This requires accurate initial clinical, laboratory, radiological, endoscopic, and/or tissue diagnosis for proper phenotypic stratification of each CD patient. A substantial proportion of patients in symptomatic remission have been reported to demonstrate evidence of active disease, with elevated fecal calprotectin(FC) and C-reactive protein (CRP) levels as a hallmark for mucosal inflammation. Active mucosal inflammation, and elevated CRP and fecal calprotectin (FC) have been shown to be good predictors of clinical relapse, disease progression, and complications in IBD patients. The next frontier of treatment is personalized medicine or precision medicine to help solve the problem of IBD heterogeneity and variable responses to treatment. Personalized medicine has the potential to increase the efficacy and/or reduce potential adverse effects of treatment for each CD phenotype. However, there is currently an unmet need for better elucidation of the inflammatory biopathways and genetic signatures of each IBD phenotype, so personalized medicine can specifically target the underlying cause of the disease and provide maximal efficacy to each patient.

Fecal Lactoferrin for Assessment of Inflammatory Bowel Disease Activity: A Systematic Review and Meta-Analysis

OBJECTIVE

Persistent disease activity is associated with a poor prognosis in inflammatory bowel disease (IBD) patients. Therefore, monitoring of IBD activity can avoid the poor prognosis. Serum biomarkers reflect a summation of systemic host responses rather than being specific for intestinal inflammation. And endoscopic monitoring is invasive, costly, and time consuming. The objective of our study was to perform a meta-analysis evaluating the diagnostic accuracy of fecal lactoferrin (FL) in assessing IBD activity.

METHODS

We systematically searched the databases from inception to May 2018 that evaluated IBD activity. The methodological quality of each study was assessed according to the Quality Assessment of Diagnostic Accuracy Studies checklist. The extracted data were pooled using a summary receiver operating characteristic curve model. Random-effects model was used to summarize the diagnostic odds ratio, sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio.

RESULTS

Ten studies comprising 773 IBD patients were included in the meta-analysis. The pooled sensitivity and specificity values for assessing ulcerative colitis (UC) activity were 0.81 [95% confidence interval (CI), 0.64-0.92] and 0.82 (95% CI, 0.61-0.93), respectively. And the pooled sensitivity and specificity values for assessing Crohn's disease (CD) activity were 0.82 (95% CI, 0.73-0.88) and 0.71 (95% CI, 0.63-0.78), respectively. The diagnostic performance of the FL assay in the UC patients appeared to be superior to that in the CD patients.

CONCLUSION

Our meta-analysis has found that FL is an inexpensive, simple, stable, and useful screening marker with high sensitivity and modest specificity for assessing IBD activity, appearing to have greater ability to evaluate UC rather than CD.

The role of platelet to lymphocyte ratio and neutrophil to lymphocyte ratio in ulcerative colitis

BACKGROUND/AIMS

Neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR) can serve as biomarkers for diagnosing and assessing disease activity in ulcerative colitis (UC). We investigated their clinical significance in UC.

METHODS

We analyzed 48 patients with UC who underwent measurement of fecal calprotectin (FC) and endoscopy and 96 age- and sex-matched healthy controls. NLR and PLR were compared between the patients and healthy controls. The endoscopic activity was divided into 2 groups: group 1 (mild to moderate inflammation) and group 2 (severe inflammation) according to the Mayo endoscopic subscore in UC.

RESULTS

To diagnose UC, the optimal cutoff of NLR and PLR was 2.26 (sensitivity 54.2%; specificity 90.6%; positive likelihood ratio 5.778, 95% confidence interval [CI] 2.944-11.339; area under the curve [AUC] 0.774, 95% CI, 0.690-0.859) and 179.8 (sensitivity 35.4%; specificity 90.6%; positive likelihood ratio 3.778, 95% CI 1.821-7.838; AUC 0.654, 95% CI 0.556-0.753), respectively. The optimal cutoff to differentiate group 1 and group 2 was 3.44, 175.9, and 453 µg/g for NLR, PLR, and FC, respectively (sensitivity, 63.6% vs. 90.9% vs. 81.8%; specificity, 81.1% vs. 78.4% vs. 73.0%; positive likelihood ratio, 3.364 vs. 4.205 vs. 3.027; AUC, 0.714 vs. 0.897 vs. 0.813). PLR had the highest AUC and positive likelihood ratio.

CONCLUSIONS

NLR and PLR help differentiate patients with UC from healthy controls. NLR, PLR, and FC indicate endoscopic activity and may reflect intestinal mucosal conditions.

Habitual dietary intake of IBD patients differs from population controls: a case-control study

BACKGROUND

Since evidence-based dietary guidelines are lacking for IBD patients, they tend to follow "unguided" dietary habits; potentially leading to nutritional deficiencies and detrimental effects on disease course. Therefore, we compared dietary intake of IBD patients with controls.

METHODS

Dietary intake of macronutrients and 25 food groups of 493 patients (207 UC, 286 CD), and 1291 controls was obtained via a food frequency questionnaire.

RESULTS

38.6% of patients in remission had protein intakes below the recommended 0.8 g/kg and 86.7% with active disease below the recommended 1.2 g/kg. Multinomial logistic regression, corrected for age, gender and BMI, showed that (compared to controls) UC patients consumed more meat and spreads, but less alcohol, breads, coffee and dairy; CD patients consumed more non-alcoholic drinks, potatoes, savoury snacks and sugar and sweets but less alcohol, dairy, nuts, pasta and prepared meals. Patients with active disease consumed more meat, soup and sugar and sweets but less alcohol, coffee, dairy, prepared meals and rice; patients in remission consumed more potatoes and spreads but less alcohol, breads, dairy, nuts, pasta and prepared meals.

CONCLUSIONS

Patients avoiding potentially favourable foods and gourmandizing potentially unfavourable foods are of concern. Special attention is needed for protein intake in the treatment of these patients.

Serum Biomarkers for Inflammatory Bowel Disease

Background: Inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis, is a chronic, inflammatory disorder of the gastrointestinal tract. As the novel therapeutic goal and biologicals are widely recognized, accurate assessment of disease and prediction of therapeutic response have become a crucial challenge in clinical practice. Also, because of the continuously rising incidence, convenient and economical methods of diagnosis and clinical assessment are urgently needed. Recently, serum biomarkers have made a great progress and become a focus in IBD study because they are non-invasive, convenient, and relatively inexpensive than are markers in biopsy tissue, stool, breath, and other body fluids.

Aims: To review the available data on serological biomarkers for IBD.

Methods: We searched PubMed using predefined key words on relevant literatures of serum biomarkers regarding diagnosis, evaluation of therapeutic efficacy, surveillance of disease activity, and assessment of prognosis for IBD.

Results: We reviewed serological biomarkers that are well-established and widely used (e.g., C-reactive protein), newly discovered biomarkers (e.g., cytokines, antibodies, and non-coding RNAs), and also recently advancements in serological biomarkers (e.g., metabolomics and proteomics) that are used in different aspects of IBD management.

Conclusions: With such a wealth of researches, to date, there are still no ideal serum biomarkers for IBD. Serum profiling and non-coding RNAs are just starting to blossom but reveal great promise for future clinical practice. Combining different biomarkers can be valuable in improving performance of disease evaluation.

Effects of an Omega-3 and Vitamin D Supplement on Fatty Acids and Vitamin D Serum Levels in Double-Blinded, Randomized, Controlled Trials in Healthy and Crohn's Disease Populations

Two trials separately measured the bioavailability and impact on inflammation of a supplement taken daily containing 510 mg Docosahexaenoic acid (DHA), 344 mg Eicosapentaenoic acid (EPA), and 1000 IU of vitamin D (25-hydroxyvitamin D; 25(OH)D), for healthy and Crohn’s disease (CD) populations. Both trials were double blinded, randomized, placebo-controlled with cross-over. Participants were randomly allocated to groups A (placebo then supplement) or B (supplement then placebo). Both included a washout. Fatty acid (N-3 PUFAs) and vitamin D serum levels, plasma C-reactive protein (CRP), and stool calprotectin were measured before and after each treatment period. Outcome measures were analyzed using generalized linear mixed models, including terms for treatment, period, and a treatment-by-period interaction. The supplement significantly increased serum levels in healthy and CD groups for EPA (p < 0.001 and p < 0.001, respectively), Docosapentaenoic acid (p < 0.001 and 0.005), DHA (p < 0.001 and 0.006), the omega-3 index (p < 0.001 and 0.001), and (vitamin D (p < 0.001 and 0.027). CRP and calprotectin measures showed no evidence of a treatment effect on inflammation; however, model estimation was imprecise for both outcomes, hence further research is required to elucidate potential inflammation effects. The nutrient supplement increased serum levels of key N-3 PUFAs and vitamin D in both populations, showing the preparation was readily bioavailable.

Is fecal calprotectin an accurate marker in the management of Crohn's disease?

Although lacking validated cutoff values, fecal calprotectin (FC), besides C-reactive protein, is considered the standard test for assessing disease activity in Crohn's disease (CD). The aim of the present review is to provide a general overview of the literature addressing the role of FC in the clinical and endoscopic assessment of disease activity in CD, seeking correlations with capsule endoscopy, response to therapy, prediction of relapse, and postoperative recurrence. A systematic search of the literature up to September 2019 was performed using Medline, Embase, and the Cochrane Library. Only papers written in English concerning FC in adult patients affected by CD were included. Pediatric studies, in vitro studies, animal studies, studies on blood/serum samples, and studies analyzing FC in ulcerative colitis or in both CD and ulcerative colitis were excluded. Out of 713 citations, 65 eligible studies were identified. FC showed high accuracy in the assessment of intestinal inflammation and response to therapy, in particular in colonic disease, thus proving a good surrogate marker for these aims. FC is useful in identifying patients at high risk for endoscopic relapse or postoperative recurrence, for optimizing or downstage therapy. Unfortunately, FC performs less well in small bowel CD. FC is an effective fecal marker in the management of CD patients, optimizing the use of endoscopic procedures. Owing to its diagnostic accuracy, FC may represent a cornerstone of the "treat-to-target" management strategy of CD patients.

Fecal MicroRNAs Show Promise as Noninvasive Crohn's Disease Biomarkers

Background

Short non-coding microRNAs (miRNAs) are involved in various cellular processes during disease progression of Crohn’s disease (CD) and remarkably stable in feces, which make them attractive biomarker candidates for reflecting intestinal inflammatory processes. Here we investigated the potential of fecal miRNAs as noninvasive and translational CD biomarkers.

Methods

MiRNAs were screened in feces of 52 patients with CD and 15 healthy controls using RNA sequencing and the results were confirmed by PCR. The relationship between fecal miRNA levels and the clinical CD activity index (CDAI) or CD endoscopic index of severity (CDEIS) was explored, respectively. Additionally, fecal miRNAs were investigated in dextran sodium sulfate, adoptive T-cell transfer, and Helicobacter typhlonius/stress-induced murine colitis models using the NanoString platform.

Results

Nine miRNAs (miR-15a-5p, miR-16-5p, miR-128-3p, miR-142-5p, miR-24-3p, miR-27a-3p, miR-223-3p, miR-223-5p, and miR-3074-5p) were significantly (adj. P < 0.05, >3-fold) increased whereas 8 miRNAs (miR-10a-5p, miR-10b-5p, miR-141-3p, miR-192-5p, miR-200a-3p, miR-375, miR-378a-3p, and let-7g-5p) were significantly decreased in CD. MiR-192-5p, miR-375, and miR-141-3p correlated (P < 0.05) with both CDAI and CDEIS whereas miR-15a-5p correlated only with CDEIS. Deregulated expression of miR-223-3p, miR-16-5p, miR-15a-5p, miR-24-3p, and miR-200a-3p was also observed in murine models. The identified altered fecal miRNA levels reflect pathophysiological mechanisms in CD, such as Th1 and Th17 inflammation, autophagy, and fibrotic processes.

Conclusions

Our translational study assessed global fecal miRNA changes of patients with CD and relevant preclinical models. These fecal miRNAs show promise as translational and clinically useful noninvasive biomarkers for mechanistic investigation of intestinal pathophysiology, including monitoring of disease progression.

MicroRNAs are involved in disease progression of Crohn’s disease (CD). This study identified significantly altered fecal levels of 17 microRNAs in CD compared to healthy subjects. These microRNAs reflect pathophysiological mechanisms and show promise as clinically useful, noninvasive CD biomarkers.

Proteomics Highlights Common and Distinct Pathophysiological Processes Associated with Ileal and Colonic Ulcers in Crohn's Disease

BACKGROUND AND AIMS

Based on genetics and natural history, Crohn's disease can be separated into two entities, an ileal and a colonic disease. Protein-based approaches are needed to elucidate whether such subphenotypes are related to distinct pathophysiological processes.

METHODS

The proteome of ulcer edges was compared with that of paired control tissue samples [n = 32 biopsies] by differential proteomics in the ileum and the colon of Crohn's disease patients [n = 16]. The results were analysed using a hypothesis-driven approach [based on the literature] and a hypothesis-free approach [pathway enrichment analyses] to determine common and segment-specific pathophysiological processes associated with ileal and colonic CD ulcer edges. To confirm the involvement of a key pathway highlighted by proteomics, two proteins were also studied by immunochemistry.

RESULTS

In the ileum and the colon, 4428 and 5204 proteins, respectively, were identified and quantified. Ileal and colonic ulcer edges differed in having a distinct distribution of proteins associated with epithelial-mesenchymal transition, neutrophil degranulation, and ribosomes. Ileal and colonic ulcer edges were similarly characterized by an increase in the proteins implicated in the endoplasmic reticulum protein-processing pathway and a decrease in mitochondrial proteins. Immunochemistry confirmed the presence of endoplasmic reticulum stress in the mucosa of ileal and colonic ulcer edges.

CONCLUSION

This study provides protein-based evidence for partially distinct pathophysiological processes being associated with ileal and colonic ulcer edges in Crohn's disease patients. This could constitute a first step toward the development of gut segment-specific diagnostic markers and therapeutics.

Long-term deep remission during maintenance therapy with biological agents in inflammatory bowel diseases

Background and aims: A multicentre, retrospective, non-interventional, patient chart review study was conducted to investigate deep (DR) and histological remission rates during maintenance therapy with biological agents in inflammatory bowel disease (IBD).Methods: We reviewed clinical, endoscopic, and histological findings, and laboratory markers such as C-reactive protein (CRP) and faecal calprotectin (FC) on average of nine years after the initiation of anti-TNF-therapy. DR was defined as no clinical symptoms (The physicians' global assessment scores; PGA = 0) with endoscopic remission (the Simple Endoscopic Score for Crohn's Disease [SES-CD] ≤ 2 or Mayo endoscopic subscore ≤1). Histological activity was defined as normal if only architectural alterations without cellularity changes occurred.Results: Of 117 IBD patients on maintenance therapy, 72 (62%; CD n = 55 [56%], UC n = 17 [85%]) patients were in DR. Of patients in DR, 76% were also in histological remission. 77% of patients remained on initiated biological treatment. UC patients achieved DR significantly more often than CD patients (p = .016). Both median CRP and FC levels were significantly lower in patients with DR.Conclusion: Reassuringly, almost two thirds of the IBD patients on maintenance therapy with biological agents maintained DR in the long-term, and more than two thirds of patients in DR achieved also histological remission. CD patients in DR had fewer surgical operations due to CD than patients not achieving DR.

Pursuing therapeutic success in Crohn’s disease: A matter of definition, tools and longterm outcomes

Management of Crohn’s disease (CD) based on symptom control is a tale of the past as new treatment strategies aim toward a “treat to target” concept and to a patient-tailored approach. Defining treatment goals and assessing therapeutic success have been in the center of IBD research in the past years. Clinical remission and mucosal healing are well-established treatment goals by current recommendations, although prospective data is required to determine whether achieving these targets is enough to alter disease natural course. Furthermore, there is no standard in assessing therapeutic success. Low relapse and hospitalization rates, as well as a low need of surgery are indicators of a successful treatment. Close monitoring is part of the new therapeutic strategy. Monitoring tools are numerous, comprising clinical, biological, endoscopic and imaging scores or parameters but are far from being perfect. The traditional strategy of managing CD patients based on clinical symptoms and response to treatment did not improve the long-term outcomes. Clinical activity scores are frequently used in clinical trials and daily practice, but their use alone is not an accurate measure of inflammation. Endoscopic remission is associated with a lower risk of complications and a better long-term prognostic. Several guidelines include recommendations regarding surveillance endoscopy, but there is an open debate regarding the follow-up intervals. Cross-sectional imaging techniques play a complementary role in assessing transmural inflammation and in identifying extra-intestinal complications of CD and should be used in conjunction with endoscopy. Therapeutic drug monitoring is essential in assessing loss of response and making therapeutic decisions, although firm recommendations are not implemented into daily practice. Extraintestinal manifestations are often disregarded when discussing monitoring protocols. There is no current guideline indication for extraintestinal manifestations monitoring during remission periods.

Fecal calprotectin as a factor that supports the pathogenicity of Dientamoeba fragilis

Calprotectin is a protein that is mostly released from neutrophils, monocytes, macrophages and submucosal epithelial cells. Fecal calprotectin (f-CP) is a marker of intestinal inflammation. There are some discussions about the pathogenicity of D. fragilis in the gastrointestinal tract. In this study, we investigated whether f-CP level is a factor supporting the pathogenicity of D. fragilis. The f-CP levels were evaluated in patients with only D. fragilis positive in comparison with healthy controls. Moreover, the levels of f-CP were investigated in fecal samples of D. fragilis negative patients with gastrointestinal complaints. The fecal samples were collected from three groups. Three groups of fecal samples were examined directly microscopy, trichrome staining, cultivation, enzyme immunoassay (EIA) and real-time PCR assay. In the first group (Group 1, n = 34), patient stool samples with gastrointestinal symptoms (without other pathogens) found only with D. fragilis were included. In the second group (Group 2, n = 31), there were patients' stool samples with gastrointestinal symptoms that D. fragilis was negative (but there may be other pathogenic agents). In the control group (Group 3, n = 23), we used fecal samples collected from healthy volunteers without any infection or gastrointestinal complaints. The collected fecal samples were stored at -20 °C until analysis. Levels of f-CP were determined by using human calprotectin ELISA kits. Total of 88 patients were enrolled in three different groups. We obtained f-CP levels as follows: 33.40 ng/mg protein in the group 1, 15.99 ng/mg protein in the group 2 and 1.54 ng/mg protein in the group 3. Statistically significant difference in f-CP levels of the group 1 and the group 2 were obtained when compared with healthy controls (p < 0.0001). However, the f-CP levels of the group 1 were not significantly different from the group 2 (p > 0.99). In conclusion, increased levels of f-CP are shown as a marker of an inflammatory disease of the lower gastrointestinal tract in infected humans. There is continues controversy about the pathogenicity of D. fragilis in symptomatic and asymptomatic patients. The findings of this study contribute to the ongoing debate about the pathogenicity of D. fragilis. In our study, the potential pathogenicity of D. fragilis is associated with increased f-CP concentrations with parasite detection in the fecal samples and therefore we assume that the parasite is not only a harmless commensal. In summary, higher levels of f-CP found in D. fragilis positive patients suggest the importance of researches that support the pathogenicity of indicated parasite.

Quality of Life Is Associated With Wearable-Based Physical Activity in Patients With Inflammatory Bowel Disease: A Prospective, Observational Study

OBJECTIVES

Patient-reported outcomes such as quality of life are gaining importance in the assessment of patients suffering from inflammatory bowel disease (IBD). The association of objectively measured physical activity and quality of life in patients with IBD has not been studied in depth. To investigate the association of disease-specific quality of life and physical activity as well as clinical and biochemical disease activity in patients with IBD.

METHODS

A total of 91 patients with IBD were stratified into 4 groups (Crohn's disease and ulcerative colitis, in remission and with moderate-severe activity, respectively) and evaluated in terms of disease-specific quality of life (Inflammatory Bowel Disease Questionnaire [IBDQ]), physical activity (accelerometry), body composition (bioelectrical impedance analysis), as well as clinical (Harvey-Bradshaw Index and Simple Clinical Colitis Activity Index) and biochemical (C-reactive protein and fecal calprotectin) parameters of disease activity.

RESULTS

In patients with moderate-severe disease activity, the IBDQ was significantly lower as compared to patients in remission (Mann-Whitney U test and Kruskal-Wallis test, P < 0.001). The physical activity level was higher in remission than in active disease (Mann-Whitney U test, P < 0.05). The IBDQ was significantly correlated with the duration of strenuous physical activity per day (P = 0.029178, r = 0.235), skeletal muscle mass (P = 0.033829, r = 0.229), and biomarkers of inflammation (C-reactive protein: P < 0.005, r = -0.335 and fecal calprotectin: P < 0.005, r = -0.385).

DISCUSSION

In this prospective, cross-sectional study, disease-specific quality of life was significantly associated with accelerometrically determined physical activity and disease activity in patients with IBD. This may be related to a reciprocal impact of these factors (DRKS00011370).

Variability of Faecal Calprotectin in Inflammatory Bowel Disease Patients: An Observational Case-control Study

BACKGROUND AND AIMS

Several factors have been reported to affect faecal calprotectin [FC] values, and significant variation in FC concentrations has been observed in inflammatory bowel disease [IBD] patients. We aimed to evaluate FC variability in IBD patients, and to assess the robustness of a single stool punch.

METHODS

This is a single-centre observational case-control study. Disease activity was assessed using endoscopic and clinical activity scores, as well as C-reactive protein levels. Stool samples were collected twice within a 1 to 6 days interval, and FC was measured on punches and homogenates by fluorometric enzyme immunocapture assay.

RESULTS

In all, 260 stool samples were collected from 120 patients. Intrastool variability was low, with an intraclass correlation coefficient for single measures between three punches from a single stool sample of 0.91, and median coefficient of variation [CV] of 17%. CV of two stool samples a few days apart [intra-individual variability] were significantly higher [p <0.01] with median CV of 36%. FC standard deviations correlated with mean FC levels either for intrastool or for intra-individual variability, with a Spearman's coefficient of rank correlation of 0.85 and 0.78, respectively [p <0.01]. Disease type, location, activity, and FC levels did not influence variability.

CONCLUSIONS

A single stool punch is reliable for FC measurement, considering that intrastool variability is low. Intra-individual variability a few days apart is significantly higher. Therefore, decision-making strategies based on single measurements should consider this variability, to determine the minimum optimal variation to be achieved, rather than a cut-off, especially in high FC levels.

Determination of lower cut-off levels of adalimumab associated with biochemical remission in Crohn's disease

Background and Aim

Adalimumab is administered and dosed using a standardized treatment regimen. Although therapeutic drug monitoring (TDM) may help optimize treatment efficacy, the lower cut‐off concentration of adalimumab needed to retain disease remission has not been established. This cross‐sectional study of patients with Crohn's disease on stable medication aimed to determine a lower therapeutic drug concentration threshold of adalimumab associated with biochemical disease remission.

Methods

C‐reactive protein (CRP) and fecal calprotectin were used as established markers and albumin as an explorative marker of disease activity. Time since introduction, treatment interval, drug dosage, serum drug concentration and antidrug antibodies, disease duration, age, and sex were recorded.

Results

The study included 101 patients who were divided into “active disease” and “remission” groups for inflammatory markers based on cut‐off levels of 5 mg/L for CRP and 50 mg/kg for fecal calprotectin. Cut‐off levels for albumin of 36.5 and 41.5 g/L were also added as further indicatives of remission. Receiver operating characteristic analysis found optimal thresholds for adalimumab associated with remission at 6.8–7.0 mg/L for the combination of CRP and fecal calprotectin and when combining CRP, fecal calprotectin, and albumin.

Conclusions

In patients with Crohn's disease, serum adalimumab of at least 6.8 mg/L was associated with biochemical disease remission based on CRP and fecal calprotectin, supporting the use of TDM to ensure disease control. Albumin should be further tested in this setting.

Anti-inflammatory Gut Microbial Pathways Are Decreased During Crohn's Disease Exacerbations

BACKGROUND AND AIMS

Crohn's disease [CD] is a chronic inflammatory disorder of the gastrointestinal tract characterised by alternating periods of exacerbation and remission. We hypothesised that changes in the gut microbiome are associated with CD exacerbations, and therefore aimed to correlate multiple gut microbiome features to CD disease activity.

METHODS

Faecal microbiome data generated using whole-genome metagenomic shotgun sequencing of 196 CD patients were of obtained from the 1000IBD cohort [one sample per patient]. Patient disease activity status at time of sampling was determined by re-assessing clinical records 3 years after faecal sample production. Faecal samples were designated as taken 'in an exacerbation' or 'in remission'. Samples taken 'in remission' were further categorised as 'before the next exacerbation' or 'after the last exacerbation', based on the exacerbation closest in time to the faecal production date. CD activity was correlated with gut microbial composition and predicted functional pathways via logistic regressions using MaAsLin software.

RESULTS

In total, 105 bacterial pathways were decreased during CD exacerbation (false-discovery rate [FDR] <0.1) in comparison with the gut microbiome of patients both before and after an exacerbation. Most of these decreased pathways exert anti-inflammatory properties facilitating the biosynthesis and fermentation of various amino acids [tryptophan, methionine, and arginine], vitamins [riboflavin and thiamine], and short-chain fatty acids [SCFAs].

CONCLUSIONS

CD exacerbations are associated with a decrease in microbial genes involved in the biosynthesis of the anti-inflammatory mediators riboflavin, thiamine, and folate, and SCFAs, suggesting that increasing the intestinal abundances of these mediators might provide new treatment opportunities. These results were generated using bioinformatic analyses of cross-sectional data and need to be replicated using time-series and wet lab experiments.

Association Between Level of Fecal Calprotectin and Progression of Crohn's Disease

BACKGROUND & AIMS

Mucosal healing is associated with improved outcomes in patients with Crohn's disease (CD), but assessment typically requires ileocolonoscopy. Calprotectin can be measured in fecal samples to determine luminal disease activity in place of endoscopy-this measurement is an important component of the treat-to-target strategy. We investigated whether levels of fecal calprotectin are associated with subsequent CD progression.

METHODS

We performed a retrospective study of 918 patients with CD (4218 patient-years of follow-up evaluation; median, 50.6 mo; interquartile range [IQR], 32.8-76.0 mo) managed at a tertiary medical center in Edinburgh, United Kingdom, from 2003 through 2015. Patients were included if they had 1 or more fecal calprotectin measurements made 3 months or more after their diagnosis. We collected clinical data and fecal calprotectin measurements and analyzed these data to identify factors associated with a composite outcome of progression in Montreal behavior, hospitalization, and resection.

RESULTS

An increased level of fecal calprotectin at the index visit was associated with subsequent progression of CD, independent of symptoms or disease location. The median level of fecal calprotectin at the index visit was 432 μg/g (IQR, 1365-998 μg/g) in patients who reached the composite end point vs 180 μg/g (IQR, 50-665 μg/g) in patients who did not. In multivariable analysis, a cut-off value of 115 μg/g calprotectin identified patients who met the end point with a hazard ratio of 2.4 (95% CI, 1.8-3.1; P < .0001).

CONCLUSIONS

In a retrospective analysis of patients with CD, we found that measurements of fecal calprotectin made during routine monitoring can identify patients at risk for disease progression, independent of symptoms or disease location. It is therefore important to screen asymptomatic patients for mucosal inflammation and pursue complete resolution of inflammation.

A Nomogram Combining Fecal Calprotectin Levels and Plasma Cytokine Profiles for Individual Prediction of Postoperative Crohn's Disease Recurrence

BACKGROUND

The aims of this study were to characterize the immune response profile in patients with Crohn's disease (CD) and early postoperative recurrence (POR), to identify predictive biomarkers, and to develop a noninvasive predictive tool for individual estimation of POR risk.

METHODS

Sixty-one patients who had undergone ileocolonic resection for CD were prospectively included and followed up for 24 months. Fecal calprotectin (FC), analytical parameters, and plasma cytokines were obtained before surgery and at various time points during postoperative follow-up. Morphological recurrence was assessed by ileocolonoscopy or magnetic resonance enterography within 6-12 months after surgery. Clinical activity was scored using the Harvey-Bradshaw Index.

RESULTS

Twenty-seven patients (44.3%) had morphological recurrence during follow-up. Fecal calprotectin values were significantly associated with POR risk over time. The receiver operating characteristic curve for FC provided an area under the curve (AUC) of 0.88 (95% confidence interval, 0.75-0.96), and morphological recurrence was best predicted by FC ≥160 μg/g at 6 months after surgery (85% sensitivity, 70% specificity, 26% predictive positive value, 98% negative predictive value [NPV]). The plasma cytokine profile showed higher presurgery interleukin (IL)-13 plasma levels and higher IL-6 and interferon (IFN)-γ levels at 6 months after surgery in patients with POR compared with patients without recurrence. The combination of FC, IL-6, and IFN-γ values at 6 months gave an AUC of 0.90 for predicting an early recurrence.

CONCLUSIONS

FC values <160 μg/g at 6 months have a high NPV to rule out early lesions. Combined values of FC, IL-6, and IFN-γ levels at 6 months postsurgery constitute a prognostic index with a high predictive capacity to assess the risk of early POR.

Noninvasive Methods For Assessing Inflammatory Bowel Disease Activity in Pregnancy: A Systematic Review

Active inflammatory bowel disease (IBD) may increase the risk of adverse outcomes during pregnancy. Our aim was to systematically review the role of noninvasive fecal tests, such as fecal calprotectin (FCP) and lactoferrin (FL), and laboratory tests including C-reactive protein (CRP), hemoglobin, and albumin in the assessment of IBD during pregnancy. A systematic search of electronic databases was performed through October 2018 for studies assessing the utility of fecal and laboratory tests in predicting IBD activity in pregnant patients. Active disease was defined based on routinely used clinical criteria such as the Harvey-Bradshaw Index or Mayo score for ulcerative colitis. Noninvasive test levels were stratified by the presence of active disease and by gestational period (preconception, first trimester, second trimester, and third trimester). Thirteen studies were included. Both FCP and FL levels were significantly higher in pregnant patients with IBD compared with those without IBD. FCP levels were also significantly higher in patients with active disease compared with those with the inactive disease during all gestational periods. Furthermore, 3 studies demonstrated no consistent correlation with serum CRP and active IBD during pregnancy. Similarly, serum albumin and hemoglobin levels did not correlate with disease activity in pregnant patients with IBD. Given the lack of high-quality evidence, only FCP appears to correlate with IBD activity in all gestational periods of pregnancy. The utility of the other noninvasive tests such as serum CRP, hemoglobin, and albumin remains to be determined in this population.

Comparison of fecal calprotectin and serum C-reactive protein in early prediction of outcome to infliximab induction therapy

Background: Fecal calprotectin (FC) and serum C-reactive protein (CRP) are biomarkers of disease activity in Crohn's disease (CD) and ulcerative colitis (UC). We assessed FC, CRP, Harvey-Bradshaw index (HBi), partial Mayo Clinic Scoring (pMCS) and a cytokine panel during infliximab induction to predict therapy outcome. Methods: FC, CRP and clinical indices were evaluated in 123 (76 CD, 47 UC) patients before infliximab induction and after 12 weeks. Responders were monitored 48 weeks for an 'incident' (dosage increase, shortened dosage interval, surgery). Cutoff values for FC and CRP were obtained using receiver-operating characteristics (ROC). Disease progression was analyzed with Kaplan-Meier survivals, log-rank test and logistic regression for combined biomarkers. Cytokines were analyzed with Luminex multiplexing system. Results: Following infliximab, FC and CRP declined (p < .0001) along with HBi for CD and pMCS for UC. Simultaneously, IL-6 and TNF-α decreased, while IL-10 increased. Optimal FC ROC cutoff was 221 µg/g (sensitivity 66%, specificity 67%, AUC 0.71) and CRP ROC cutoff 2.1 mg/L (sensitivity 54%, specificity 60%, AUC 0.58). In CD, FC > 221 µg/g (p < .0001), but not CRP > 2.1 mg/L predicted an 'incident'. However, combined FC and CRP also predicted an 'incident' (p < .042). In UC, both FC > 221 µg/g (p < .0005) and CRP > 2.1 mg/L (p = .0334) predicted 'incident', as did combined biomarkers (p < .005). Conclusions: Clinical disease activity is reduced by treatment with infliximab. In CD, persistently high FC, but not CRP, predict a treatment 'incident', whereas in UC both high FC and high CRP predict 'incident'. Combined FC and CRP values also predict an 'incident'.

Canadian Association of Gastroenterology Clinical Practice Guideline for the Management of Luminal Crohn's Disease

BACKGROUND & AIMS

Crohn's disease (CD) is a lifelong illness with substantial morbidity, although new therapies and treatment paradigms have been developed. We provide guidance for treatment of ambulatory patients with mild to severe active luminal CD.

METHODS

We performed a systematic review to identify published studies of the management of CD. The quality of evidence and strength of recommendations were rated according to the Grading of Recommendation Assessment, Development and Evaluation (GRADE) approach. Statements were developed through an iterative online platform and then finalized and voted on by a group of specialists.

RESULTS

The consensus includes 41 statements focused on 6 main drug classes: antibiotics, 5-aminosalicylate, corticosteroids, immunosuppressants, biologic therapies, and other therapies. The group suggested against the use of antibiotics or 5-aminosalicylate as induction or maintenance therapies. Corticosteroid therapies (including budesonide) can be used as induction, but not maintenance therapies. Among immunosuppressants, thiopurines should not be used for induction, but can be used for maintenance therapy for selected low-risk patients. Parenteral methotrexate was proposed for induction and maintenance therapy in patients with corticosteroid-dependent CD. Biologic agents, including tumor necrosis factor antagonists, vedolizumab, and ustekinumab, were recommended for patients failed by conventional induction therapies and as maintenance therapy. The consensus group was unable to clearly define the role of concomitant immunosuppressant therapies in initiation of treatment with a biologic agent.

CONCLUSIONS

Optimal management of CD requires careful patient assessment, acknowledgement of patient preferences, evidence-based use of existing therapies, and thorough assessment to define treatment success.

Modification of lactoferrin by peroxynitrite reduces its antibacterial activity and changes protein structure

Lactoferrin (LF) is a multifunctional protein that plays important physiological roles as one of the most concentrated proteins in many human and other mammalian fluids and tissues. In particular, LF provides antibacterial properties to human milk, saliva, and tear fluid. LF also protects against stress-induced lipid peroxidation at inflammation sites through its iron-binding ability. Previous studies have shown that LF can be efficiently nitrated via biologically relevant mediators such as peroxynitrite (ONOO^- ), which are also present at high intracellular concentrations during inflammation and nitrosative stress. Here, we examine changes in antibacterial properties and structure of LF following ONOO^- treatment. The reaction induces nitration of tyrosine and tryptophan residues, which are commonly used as biomarker molecules for several diseases. Treatment with ONOO^- at a 10/1 M ratio of ONOO^- to tyrosine inhibited all antibacterial activity exhibited by native LF. Secondary structural changes in LF were assessed using circular dichroism spectroscopy. Nitration products with and without the addition of Fe³⁺ show significant reduction in alpha-helical properties, suggesting partial protein unfolding. Iron-binding capacity of LF was also reduced after treatment with ONOO^- , suggesting a decreased ability of LF to protect against cellular damage. LC-MS/MS spectrometry was used to identify LF peptide fragments nitrated by ONOO^- , including tyrosine residue Y92 located in the iron-binding region. These results suggest that posttranslational modification of LF by ONOO^- could be an important pathway to exacerbate infection, for example, in inflamed tissues and to reduce the ability of LF to act as an immune responder and decrease oxidative damage.

Usefulness of confocal laser endomicroscopy for predicting postoperative recurrence in patients with Crohn's disease: a pilot study

BACKGROUND AND AIMS

Confocal laser endomicroscopy (CLE) has been shown to predict relapse in inflammatory bowel disease, but its value in the detection of postoperative recurrence in Crohn's disease (CD) is unknown. The aims of this pilot study performed in patients with CD after ileocolonic resection were to compare the macroscopic appearance of the neoterminal ileum, according to the endoscopic Rutgeerts score, with the microscopic findings provided by CLE 6 to 12 months after surgery and to assess the predictive values of CLE-generated parameters for predicting further recurrence in patients with postoperative endoscopic remission.

METHODS

In 25 consecutive patients with CD within 6 to 12 months of surgery, the neoterminal ileum was examined by standard white-light endoscopy (Rutgeerts scale) followed by CLE (Watson grade). Only patients without endoscopic recurrence (Rutgeerts i0 and i1) were then followed endoscopically and clinically (median follow-up 38 months).

RESULTS

At the time of the first postoperative colonoscopy, 18 patients (72%) were in endoscopic remission, and 7 (28%) experienced an endoscopic recurrence (Rutgeerts ≥i2). The Rutgeerts score was significantly correlated with the Watson score (ρ = 0 .73; P < .0001). The Watson scores at baseline were significantly higher in patients with further endoscopic recurrence (median 2.0; interquartile range [IQR] 1.5-2.0) than in those with endoscopic remission (median 1.0; IQR 1.0-1.0; P = .032) and were significantly higher in patients with clinical relapse (medium 2.0, IQR 2.0-2.0) compared with those in clinical remission (median 1.0; IQR 1.0-1.0; P = .036).

CONCLUSIONS

CLE could be useful in monitoring patients with CD after intestinal resection. Further studies with a larger population are necessary to confirm these preliminary results.

Prediction of treatment outcome and relapse in inflammatory bowel disease

Prediction of treatment outcome and clinical relapse in patients with inflammatory bowel disease (IBD), either ulcerative colitis (UC) or Crohn's disease (CD), is particularly important because therapeutics for IBD are not always effective and patients in remission could frequently relapse. Because undergoing endoscopy for the purpose is sometimes invasive and burdensome to patients, the performance of surrogate biomarkers has been investigated. Areas covered: We particularly featured the performance of patient symptoms, blood markers including C-reactive protein (CRP), fecal markers including fecal calprotectin (Fcal) and fecal immunochemical test (FIT) for prediction of endoscopic mucosal healing (MH) and prediction of relapse. Studies of other modalities and therapeutic drug monitoring (TDM) have also been explored. Expert opinion: Meticulous evaluation of patient symptoms could be predictive for MH in UC. CRP and Fcal may be accurate in prediction of MH of CD when MH is evaluated throughout the entire intestine including the small bowel. Repeated measurements of fecal markers including Fcal and FIT in patients with clinical remission would raise predictability of relapse. Prediction of treatment outcome by monitoring with blood markers including CRP, fecal markers including Fcal, and TDM has frequently been performed in recent clinical trials and shown to be effective.

Endoscopic scoring systems for the evaluation and monitoring of disease activity in Crohn's disease

Crohn's disease is a chronic relapsing idiopathic condition that can affect any part of the gastrointestinal tract. It has been shown that mucosal healing is associated with improved clinical outcomes such as reduced risk of surgery, hospitalization and complications. Nowadays mucosal healing is considered the optimal target of medical therapy. To evaluate the mucosa in an objective and standardized manner, it is important to rely on accurate and validated endoscopic scores. The Crohn's disease endoscopic index of severity, the simple endoscopic score for Crohn's disease as well as the Rutgeerts score will be reviewed. Their clinical implications and limitations will be discussed.

IBDoc Canadian User Performance Evaluation

BACKGROUND

Fecal calprotectin (FC) is a stool biomarker that has been shown to be sensitive and specific for mucosal inflammation in patients with inflammatory bowel disease (IBD). The test is limited by the requirement for patients to collect and return stool samples. A home-based FC test may improve test adherence. The aim of this study is to evaluate the usability of the IBDoc, a home-based FC measuring test, and to determine the accuracy of results compared with traditional lab-based ELISA values.

METHODS

Patients were prospectively enrolled from 3 tertiary sites across Canada between May and August 2017. Patients completed a questionnaire establishing ease-of-use of the IBDoc. Patients completed a FC measurement using the IBDoc, and results were compared with an ELISA-determined FC measurement on the same stool sample.

RESULTS

Sixty-one participants were enrolled in the study (29 CD, 32 UC). Seventy-nine percent of patients (48 of 61) agreed that the IBDoc was easy to use, with 85% (52 of 61) of patients strongly agreeing that they were willing use the home kit in the future. The IBDoc and ELISA measurement comparison showed an 88% agreement across all values. There were no false positives or negatives using qualitative comparison.

CONCLUSIONS

The home-based IBDoc FC measuring test is acceptable to patients and correlates extremely well with the standard ELISA-determined FC value. The IBDoc enables clinicians to more easily adopt a treat-to-target approach, improve long-term outcomes, and patients' quality of life with IBD. This study is registered at ClinicalTrials.gov, number NCT03408249.

Fecal Calprotectin, Gut Inflammation and Spondyloarthritis

BACKGROUND

Gut inflammation is closely related to spondyloarthritis (SpA) pathophysiology. Fecal calprotectin has been used to measure the degree of gut inflammation. The phenotype of SpA may change according to studied population.

AIM

To study the fecal calprotectin levels in a sample of SpA in Brazilian patients and its relationship with epidemiological, clinical and treatment variables as well as with the macro and microscopic degree of gut inflammation.

METHODS

Eighty five SpA patients were studied for epidemiological and clinical features, functional and inflammatory indexes and fecal calprotectin levels measured using a ELISA kit. Colonoscopy with intestinal biopsies were performed in 39 of them. At time of colonoscopy a second calprotectin level was done after suspension of at least 3 weeks of used anti-inflammatory nonsteroidal drugs (NSAIDs).

RESULTS

Fecal calprotectin levels were higher in Ankylosing Spondylitis (AS) patients (p <0.0001) and in those with axial involvement (p = 0.002). No relationship was found with SpA inflammatory and functional parameters (all p = ns). After suspension of NSAIDs, a drop in fecal calprotectin levels was observed (from median levels of 215.0-76.0 μg/g; p = 0.01). In the colonoscopy, 33.3% had macroscopic signs of inflammation and these patients had higher calprotectin (p = 0.009) than others. Microscopic examination showed that all patients had lymphoplasmacytic infiltrate and eosinophilic infiltrate; epithelial erosion was present in 27.2%.

CONCLUSIONS

Patients with ankylosing spondylitis and axial forms of diseases have higher fecal calprotectin levels. Patients with all types of SpA have microscopic inflammatory changes in the gut.

Does fecal calprotectin equally and accurately measure disease activity in small bowel and large bowel Crohn's disease?: a systematic review

Fecal calprotectin (FC) is a highly sensitive disease activity biomarker in inflammatory bowel disease. However, there are conflicting reports on whether the diagnostic accuracy in Crohn's disease is influenced by disease location. The aim of this study was to undertake a systematic review of the published literature. Relevant databases were searched from inception to November 8, 2016 for cohort and case control studies which had data on FC in patients with isolated small bowel (SB) and large bowel (LB) Crohn's disease. Reference standards for disease activity were endoscopy, magnetic resonance imaging, computed tomography or a combination of these. The QUADAS-2 research tool was used to assess the risk of bias. There were 5,619 records identified at initial search. The 2,098 duplicates were removed and 3,521 records screened. Sixty-one full text articles were assessed for eligibility and 16 studies were included in the final review with sensitivities and specificities per disease location available from 8 studies. Sensitivities of FC at SB and LB locations ranged from 42.9% to 100% and 66.7% to 100% respectively while corresponding specificities were 50% to 100% and 28.6% to 100% respectively. The sensitivities and specificities of FC to accurately measure disease activity in Crohn's disease at different disease locations are diverse and no firm conclusion can be made. Better studies need to be undertaken to categorically answer the effect of disease location on the diagnostic accuracy of FC.

The role of fecal calprotectin in pediatric disease

Fecal calprotectin (FC) is a calcium- and zinc-binding protein of the S100 family, mainly expressed by neutrophils and released during inflammation. FC became an increasingly useful tool both for gastroenterologists and for general practitioners for distinguishing inflammatory bowel disease (IBD) from irritable bowel syndrome. Increasing evidences support the use of this biomarker for diagnosis, follow-up and evaluation of response to therapy of several pediatric gastrointestinal diseases, ranging from IBD to nonspecific colitis and necrotizing enterocolitis. This article summarizes the current literature on the use of FC in clinical practice.

Diagnostic accuracy of faecal calprotectin in patients with active perianal fistulas

Background

Faecal calprotectin (FC) is a marker of mucosal inflammation.

Objective

The aim of this study was to determine the diagnostic accuracy of FC to (a) differentiate between perianal fistulizing Crohn's disease (pCD) and cryptoglandular perianal fistulas; and (b) detect mucosal inflammation in pCD.

Methods

Patients with active perianal fistulas who had FC measured and a complete ileocolonoscopy within 10 weeks were retrospectively included.

Results

Fifty-six patients were included (pCD, n = 37) of whom 19 pCD patients exhibited ulcers. FC was significantly higher in pCD compared to cryptoglandular fistulas (µg/g) (708.0 (207.0-1705.0) vs 32.0 (23.0-77.0), p < 0.001). Area-under-the-curve (AUC) value for FC receiver operating characteristic (ROC) statistics was 0.900. Optimal FC cut-off was ≥ 150 µg/g. To differentiate pCD from cryptoglandular fistulas in the absence of luminal inflammation, optimal cut-off remained ≥ 150 µg/g (AUC = 0.857, sensitivity = 0.81, specificity = 0.89, positive predictive value (PPV) = 93.8% and negative predictive value (NPV) = 70.8%). In pCD, FC was significantly increased in the presence of ulcers (1672.0 vs 238.0, p = 0.004). Optimal cut-off was ≥ 250 µg/g (AUC = 0.776; sensitivity = 0.89, specificity = 0.56, PPV - 68.0% and NPV = 83.0%).

Conclusion

FC discriminates pCD from cryptoglandular fistulas, even in the absence of intestinal ulcers. In active pCD, an elevated FC does not accurately predict the presence of ulcers and should be interpreted with caution.