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

Diagnosis and Differentiation of Inflammatory Bowel Disease

Differentiating Crohn's disease from ulcerative colitis may be a diagnostic challenge for clinicians due to overlapping features. However, the correct diagnosis may guide treatment options and considerations regarding surgery. This study reviews the common components of diagnostic evaluation of inflammatory bowel disease. Additionally, this article provides a basis of understanding for the more complex aspects of the disease to be discussed in subsequent studies.

The usefulness of serum leucine-rich alpha-2 glycoprotein as a novel biomarker in monitoring inflammatory bowel disease: a systematic review and meta-analysis

Inflammatory bowel disease (IBD) is a condition of unknown origin. It does not have a definite cure and its response to various treatments can be evaluated based on symptom-based measures, invasive procedures, or biomarker levels, highlighting the need for an accurate biomarker. Since C-reactive protein (CRP) and fecal calprotectin have their shortcomings, the need for a novel biomarker remains critical. Systematic searches of PubMed, Scopus, Web of Science, and Embase were performed In January 2024. PROSPERO number is CRD42024507383. We assessed the accuracy of leucine-rich alpha-2 glycoprotein (LRG) in identifying disease activity among patients with IBD using a bivariate diagnostic random-effects model. Fourteen studies involving 1794 individuals conducted in Japan were selected for our systematic review. The sensitivity and specificity of LRG levels for detecting disease activity were analyzed in patients with IBD and in two subgroups (ulcerative colitis and Crohn's disease). The synthesized sensitivity and specificity were 75.4% [95% confidence interval (CI), 68.9-80.9%] and 77.3% (95% CI, 69.9-83.2%), respectively, in patients with IBD, 73.1% (95% CI, 62.7-81.5%) and 81.9% (95% CI, 73.9-87.8%), respectively, in patients with CD, and the secondary analysis of the ulcerative colitis subgroup showed a pooled sensitivity and specificity of 72.8 and 59.7%, respectively. Our systematic review and meta-analysis demonstrated that LRG could be useful in detecting IBD activity. It is superior for detecting disease activity, especially in patients with normal CRP levels. The LRG was more accurate in monitoring disease activity in patients with CD than in patients with IBD.

Preadsorbed Particles with Cross-Shaped DNA Scaffolds Enable Spherical Nucleic Acid to Directly Respond to Protein in Complex Matrices

Spherical nucleic acids (SNAs) usually suffer from an undesired protein corona and disrupt the function of nucleic acids (e.g., aptamer), thereby compromising recognition and response to proteins in the biological environment. To overcome the unexpected protein interference, specific proteins were initially adsorbed onto magnetic particles (MPs) as a customized protein corona "shield" with fabricated nucleic acid scaffolds, forming a preadsorbed particle-based spherical nucleic acid (pap-SNA). By comparing with AuNPs-SNA or COOH-MPs, it was found that such a protein corona "shield" of pap-SNA significantly eliminated the adsorption of nonspecific proteins or other biomolecules onto the MPs' interface, thereby enabling the SNA to directly respond to proteins in complex matrices. To further reduce the interference of protein on SNA performance, a series of nucleic acid scaffolds (Z-type, dsDNA type, circle type, T-type, and cross-shaped type) were designed by changing the rigidity and thermal stability of functional nucleic acids on the MPs. As a consequence, the pap-SNA with a cross-shaped scaffold improved the sensitivity of the pap-SNA-based detection platform in that the orderly arrangement of functional nucleic acids provides a steric hindrance to interferents. Moreover, the presence of the cross-shaped scaffold not only enables pap-SNA to exhibit a proportional response to varied protein concentrations but also enhances the detection sensitivity of pap-SNA by 160% in serum and by 190% in urine. Therefore, incorporating optimized DNA scaffolds maintained and facilitated the function of a probe (aptamer) on the surface of SNA. This approach offers a pathway for creating SNA with direct response and anti-interference capability applicable to detecting diverse biomolecules such as nucleic acids and proteins in biological matrices.

Precision Medicine in Inflammatory Bowel Disease: A Spotlight on Emerging Molecular Biomarkers

Inflammatory bowel diseases (IBD) remain challenging in terms of understanding their causes and in terms of diagnosing, treating, and monitoring patients. Modern diagnosis combines biomarkers, imaging, and endoscopic methods. Common biomarkers like CRP and fecal calprotectin, while invaluable tools, have limitations and are not entirely specific to IBD. The limitations of existing markers and the invasiveness of endoscopic procedures highlight the need to discover and implement new markers. With an ideal biomarker, we could predict the risk of disease development, as well as the possibility of response to a particular therapy, which would be significant in elucidating the pathogenesis of the disease. Recent research in the fields of machine learning, proteomics, epigenetics, and gut microbiota provides further insight into the pathogenesis of the disease and is also revealing new biomarkers. New markers, such as BAFF, PGE-MUM, oncostatin M, microRNA panels, αvβ6 antibody, and S100A12 from stool, are increasingly being identified, with αvβ6 antibody and oncostatin M being potentially close to being presented into clinical practice. However, the specificity of certain markers still remains problematic. Furthermore, the use of expensive and less accessible technology for detecting new markers, such as microRNAs, represents a limitation for widespread use in clinical practice. Nevertheless, the need for non-invasive, comprehensive markers is becoming increasingly important regarding the complexity of treatment and overall management of IBD.

Application of lactoferrin in food packaging: A comprehensive review on opportunities, advances, and horizons

Lactoferrin (LAC) is an iron-binding glycoprotein found in mammalian secretion, such as milk and colostrum, which has several advantageous biological characteristics, such as antioxidant and antimicrobial activity, intestinal iron absorption and regulation, growth factor activity, and immune response. LAC is an active GRAS food ingredient and can be included in the food packaging/film matrix in both free and encapsulated forms to increase the microbial, mechanical, barrier, and thermal properties of biopolymer films. Additionally, LAC-containing films maintain the quality of fresh food and extend the shelf life of food products. This paper primarily focuses on examining how LAC affects the antimicrobial, antioxidant, physical, mechanical, thermal, and optical properties of packaging films. Moreover, the paper explains the attributes of films incorporating LAC within different matrices, exploring the interaction between LAC and polymers. The potential of LAC-enhanced food packaging technologies is highlighted, showcasing their promising applications in sustainable food packaging.

Diagnostic Procedures for Inflammatory Bowel Disease: Laboratory, Endoscopy, Pathology, Imaging, and Beyond

Diagnosing inflammatory bowel disease (IBD) can often be challenging, and differentiating between Crohn's disease and ulcerative colitis can be particularly difficult. Diagnostic procedures for IBD include laboratory tests, endoscopy, pathological tests, and imaging tests. Serological and stool tests can be easily performed in an outpatient setting and provide critical diagnostic clues. Although endoscopy is an invasive procedure, it offers essential diagnostic information and allows for tissue biopsy and therapeutic procedures. Video capsule endoscopy and device-assisted enteroscopy are endoscopic procedures used to evaluate the small bowel. In addition to endoscopy, magnetic resonance imaging, computed tomography, and ultrasound (US) are valuable tools for small bowel assessment. Among these, US is noninvasive and easily utilized, making its use highly practical in daily clinical practice. Endoscopic biopsy aids in the diagnosis of IBD and is crucial for assessing the histological activity of the disease, facilitating a thorough evaluation of disease remission, and aiding in the development of treatment strategies. Recent advances in artificial intelligence hold promise for enhancing various aspects of IBD management, including diagnosis, monitoring, and precision medicine. This review compiles current procedures and promising future tools for the diagnosis of IBD, providing comprehensive insights.

The role of fecal biomarkers in individuals with inflammatory bowel disease

INTRODUCTION

Inflammatory bowel disease (IBD), encompassing Crohn's disease (CD) and Ulcerative Colitis (UC), is a relapsing and remitting condition. Noninvasive biomarkers have an increasingly important role in the diagnosis of IBD and in the prediction of future disease course in individuals with IBD. Strategies for the management of IBD increasingly rely upon close monitoring of gastrointestinal inflammation.

AREAS COVERED

This review provides an update on the current understanding of established and novel stool-based biomarkers in the diagnosis and management of IBD. It also highlights key gaps, identifies limitations, and advantages of current markers, and examines aspects that require further study and analysis.

EXPERT OPINION

Current noninvasive inflammatory markers play an important role in the diagnosis and management of IBD; however, limitations exist. Future work is required to further characterize and validate current and novel markers of inflammation. In addition, it is essential to better understand the roles and characteristics of noninvasive markers to enable the appropriate selection to accurately determine the condition of the intestinal mucosa.

Epigenomics and the Brain-gut Axis: Impact of Adverse Childhood Experiences and Therapeutic Challenges

The brain-gut axis represents a bidirectional communication network that integrates neural, hormonal, and immunological signaling between the central nervous system and the gastrointestinal tract. Adverse childhood experiences (ACEs) have increasingly been recognized for their profound impact on this axis, with implications for both mental and physical health outcomes. This mini-review explores the emerging field of epigenomics-specifically, how epigenetic modifications incurred by ACEs can influence the brain-gut axis and contribute to the pathophysiology of various disorders. We examine the evidence linking epigenetic mechanisms such as DNA methylation, histone modifications, and non-coding RNAs to the modulation of gene expression involved in stress responses, neurodevelopment, and immune function-all of which intersect at the brain-gut axis. Additionally, we discuss the emerging potential of the gut microbiome as both a target and mediator of epigenetic changes, further influencing brain-gut communication in the context of ACEs. The methodological and therapeutic challenges posed by these insights are significant. The reversibility of epigenetic marks and the long-term consequences of early life stress require innovative and comprehensive approaches to intervention. This underscores the need for comprehensive strategies encompassing psychosocial, pharmacological, neuromodulation, and lifestyle interventions tailored to address ACEs' individualized and persistent effects. Future directions call for a multi-disciplinary approach and longitudinal studies to uncover the full extent of ACEs' impact on epigenetic regulation and the brain-gut axis, with the goal of developing targeted therapies to mitigate the long-lasting effects on health.

The search for gastrointestinal inflammation in autism: a systematic review and meta-analysis of non-invasive gastrointestinal markers

BACKGROUND

Gastrointestinal symptoms and inflammatory gastrointestinal diseases exist at higher rates in the autistic population. It is not clear however whether autism is associated with elevated gastrointestinal inflammation as studies examining non-invasive faecal biomarkers report conflicting findings. To understand the research landscape and identify gaps, we performed a systematic review and meta-analysis of studies measuring non-invasive markers of gastrointestinal inflammation in autistic and non-autistic samples. Our examination focused on faecal biomarkers as sampling is non-invasive and these markers are a direct reflection of inflammatory processes in the gastrointestinal tract.

METHODS

We extracted data from case-control studies examining faecal markers of gastrointestinal inflammation. We searched PubMed, Embase, Cochrane CENTRAL, CINAHL, PsycINFO, Web of Science Core Collection and Epistemonikos and forward and backwards citations of included studies published up to April 14, 2023 (PROSPERO CRD42022369279).

RESULTS

There were few studies examining faecal markers of gastrointestinal inflammation in the autistic population, and many established markers have not been studied. Meta-analyses of studies examining calprotectin (n = 9) and lactoferrin (n = 3) were carried out. A total of 508 autistic children and adolescents and 397 non-autistic children and adolescents were included in the meta-analysis of calprotectin studies which found no significant group differences (ROM: 1.30 [0.91, 1.86]). Estimated differences in calprotectin were lower in studies with siblings and studies which did not exclude non-autistic controls with gastrointestinal symptoms. A total of 139 autistic participants and 75 non-autistic controls were included in the meta-analysis of lactoferrin studies which found no significant group differences (ROM: 1.27 [0.79, 2.04]).

LIMITATIONS

All studies included in this systematic review and meta-analysis examined children and adolescents. Many studies included non-autistic controls with gastrointestinal symptoms which limit the validity of their findings. The majority of studies of gastrointestinal inflammation focused on children under 12 with few studies including adolescent participants. Most studies that included participants aged four or under did not account for the impact of age on calprotectin levels. Future studies should screen for relevant confounders, include larger samples and explore gastrointestinal inflammation in autistic adolescents and adults.

CONCLUSIONS

There is no evidence to suggest higher levels of gastrointestinal inflammation as measured by calprotectin and lactoferrin are present in autistic children and adolescents at the population level. Preliminary evidence suggests however that higher calprotectin levels may be present in a subset of autistic participants, who may be clinically characterised by more severe gastrointestinal symptoms and higher levels of autistic traits.

Biosensing Intestinal Alkaline Phosphatase by Pregnancy Test Strips Based on Target-Triggered CRISPR-Cas12a Activity to Monitor Intestinal Inflammation

With an increasing incidence worldwide, inflammatory bowel disease (IBD) is a chronic inflammatory disease affecting the gastrointestinal tract, which impairs the life quality of patients. Therefore, it is of great significance to construct a sensitive, simple, and convenient biosensor to analyze IBD-associated biomarkers for an auxiliary diagnosis of IBD. Intestinal alkaline phosphatase (IAP), expressed by the intestinal epithelium, is an endogenous protein that is thought to play a vital role in maintaining intestinal homeostasis and is considered a potential biomarker for IBD. Here, an IAP detection method was developed using pregnancy test strips by dephosphorylation. Initially, a double-stranded DNA (dsDNA) was designed to respond to IAP and acted as an activator of Cas12a. In the presence of IAP, the designed dsDNA was not digested by lambda exonuclease (λ exo), which hybridized to the Cas12a-crRNA duplex and resulted in the activation of the trans-cleavage of Cas12a. Further, the activated Cas12a cleaved the single-strand DNA (ssDNA) linker in the MBs-ssDNA-hCG probe, triggering the release of hCG. With magnetic separation, the released hCG could be quantitatively detected by pregnancy test strips. IAP levels were analyzed in feces from colitis and healthy mice by pregnancy test strips. The results showed that the IAP level of colitis mice (3.89 ± 1.92 U/L) was much lower than that of healthy mice (39.64 ± 24.93 U/L), indicating the correlation between IAP and intestinal inflammation. Taken together, a sensitive, user-friendly detection assay based on pregnancy test strips was constructed to monitor IAP and used as an auxiliary diagnostic approach for IBD in a clinical scene.

Fecal Calprotectin in Gastrointestinal Disease

BACKGROUND

Inflammatory bowel disease (IBD) comprises a group of chronic conditions characterized by relapsing and remitting inflammation of the gastrointestinal tract. The incidence is increasing worldwide, and the therapeutic options for management are expanding. Endoscopy is the gold standard investigation for diagnosis of IBD and for assessing mucosal healing, which is increasingly being used as a measure of disease control. However, it is an invasive procedure that is unpleasant for patients and expensive and time-consuming for hospitals. Fecal calprotectin has been shown to be an accurate surrogate marker of gastrointestinal inflammation in IBD.

CONTENT

Fecal calprotectin was initially used for the diagnosis of IBD but is now recognized as having a role in assisting in assessment of disease activity, prediction of relapse, and informing decisions around therapy and may help to minimize requirement for endoscopy. However, there are various preanalytical and analytical factors that can affect interpretation of the results; these need to be understood to optimize clinical care.

SUMMARY

Preanalytical and analytical factors that can potentially influence fecal calprotectin concentrations are examined, and an overview is provided of clinical situations in which fecal calprotectin is commonly measured.

A Point-of-Care Faecal Test Combining Four Biomarkers Allows Avoidance of Normal Colonoscopies and Prioritizes Symptomatic Patients with a High Risk of Colorectal Cancer

Most colonoscopies performed to evaluate gastrointestinal symptoms detect only non-relevant pathologies. We aimed to evaluate the diagnostic accuracy of a qualitative point-of-care (POC) test combining four biomarkers (haemoglobin, transferrin, calprotectin, and lactoferrin), a quantitative faecal immunochemical test (FIT) for haemoglobin, and a quantitative faecal calprotectin (FC) test in symptomatic patients prospectively recruited. Colorectal cancer (CRC), adenoma requiring surveillance, inflammatory bowel disease (IBD), microscopic colitis, and angiodysplasia were considered significant pathologies. A total of 571 patients were included. Significant pathology was diagnosed in 118 (20.7%), including 30 CRC cases (5.3%). The POC test yielded the highest negative predictive values: 94.8% for a significant pathology and 100% for CRC or IBD if the four markers turned negative (36.8% of the patients). Negative predictive values of FIT, FC, and its combination for diagnosis of a significant pathology were 88.4%, 87.6%, and 90.8%, respectively. Moreover, the positive predictive value using the POC test was 82.3% for significant pathology when all biomarkers tested positive (6% of the patients), with 70.6% of these patients diagnosed with CRC or IBD. The AUC of the POC test was 0.801 (95%CI 0.754-0.848) for the diagnosis of a significant pathology. Therefore, this POC faecal test allows the avoidance of unnecessary colonoscopies and prioritizes high risk symptomatic patients.

Value of dynamic analysis of fecal lactoferrin for prediction of response to biotherapy in patients with ulcerative colitis

BACKGROUND

Ulcerative colitis (UC) is a common intestinal inflammatory disease. Biological agents are an effective treatment for UC patients, but some patients are still unresponsive to biological therapy. Therefore, it is of great significance to explore the factors affecting the response to biological therapy.

AIM

To analyze the value of dynamic analysis of fecal lactoferrin (FL) in predicting the response to biotherapy in patients with UC.

METHODS

A total of 168 UC patients admitted to our hospital from July 2018 to September 2021 were selected as the research subjects. All patients were treated with adalimumab. After 12 wk of continuous treatment, they were divided into an effective group and an ineffective group according to the response to treatment. The rates of changes in general data, serum biomarkers, and fecal biomarkers were compared between the two groups. Multivariate logistic regression analysis was used to identify the factors related to biotherapy responsiveness, and the area under the curve was calculated by ROC curve analysis.

RESULTS

There were 132 cases in the effective group and 36 in the ineffective group. After 2 wk of treatment, the rates of changes of CRP, ESR, and PCT in the effective group were greater than those in the ineffective group. The change rates of FC, FL, M2-PK and MMP-9 were also higher than those of the ineffective group (P < 0.05). Logistic regression analysis showed that ESR, PCT, FC and FL were all predictive factors for the response to biotherapy in patients with UC (odds ratio = 0.943, 0.859, 0.964 and 0.875, respectively, P < 0.05 for all). The area under the curve (0.831) of FL was higher than those of ESR, CRP, PCT, FL, MMP-9 and M2-PK (P < 0.05 for all).

CONCLUSION

ESR, PCT, FC and FL can all predict the therapeutic response to biological therapy in UC patients, among which FL has the highest predictive value.

Effect of disease duration on fecal biomarkers in ulcerative colitis: a prospective cohort study

BACKGROUND

Biomarkers such as fecal calprotectin (FC) and fecal immunochemical occult blood tests (FIT) for ulcerative colitis (UC) are used in clinical practice. In this study, the effect of UC disease duration on FC was investigated and compared to that on FIT.

METHODS

One hundred twenty-eight colonoscopic examinations and two fecal biomarkers measurements were performed. The cases of UC were divided into short- and long-term disease-duration groups or categorized into three groups with disease durations of 0-5, 6-13, and 14-38 years. We analyzed correlations between biomarker levels and endoscopic scores, including the Mayo endoscopic subscore (MES), ulcerative colitis endoscopic index of severity, and the sum of MES.

RESULTS

In the analysis of short- and long-term disease durations, the three endoscopic scores and biomarker levels showed significant correlations in both long-term and short-term groups. Most of the correlation coefficients for the individual long-term group were lower than the corresponding values for all cases, while most of the correlation coefficients for the individual short-term groups were higher than the corresponding values for all cases. In the three-group analysis (disease durations of 0-5, 6-13, and 14-38 years), the two biomarkers and three endoscopic scores showed significant correlations, and most of the correlation coefficients between biomarkers and endoscopic scores tended to be lower in the long-term follow-up group. In the receiver operating characteristic analysis for predicting mucosal healing in the three groups, the area under the curve for FC and FIT concentrations in the 0-5 year disease-duration group showed particularly higher values than those for the other two groups.

CONCLUSIONS

Similar to FIT, FC is affected by the duration of UC, indicating that FC may be a highly useful biomarker, especially in short-term disease.

Inflammatory bowel disease biomarkers

Inflammatory bowel disease (IBD) is characterized as chronic inflammation in the gastrointestinal tract, which includes two main subtypes, Crohn's disease and ulcerative colitis. Endoscopy combined with biopsy is the most effective way to establish IBD diagnosis and disease management. Imaging techniques have also been developed to monitor IBD. Although effective, the methods are expensive and invasive, which leads to pain and discomfort. Alternative noninvasive biomarkers are being explored as tools for IBD prognosis and disease management. This review focuses on novel biomarkers that have emerged in recent years. These serological biomarkers and microRNAs could potentially be used for disease management in IBD, thereby decreasing patient discomfort and morbidity.

Diagnostic Utility of Non-invasive Tests for Inflammatory Bowel Disease: An Umbrella Review

BACKGROUND

This study aims to consolidate evidence from published systematic reviews and meta-analyses evaluating the diagnostic performances of non-invasive tests for inflammatory bowel disease (IBD) in various clinical conditions and age groups.

METHODS

Two independent reviewers systematically identified and appraised systematic reviews and meta-analyses assessing the diagnostic utility of non-invasive tests for IBD. Each association was categorized as adults, children, and mixed population, based on the age ranges of patients included in the primary studies. We classified clinical scenarios into diagnosis, activity assessment, and predicting recurrence.

RESULTS

In total, 106 assessments from 43 reviews were included, with 17 non-invasive tests. Fecal calprotectin (FC) and fecal lactoferrin (FL) were the most sensitive for distinguishing IBD from non-IBD. However, anti-neutrophil cytoplasmic antibodies (ANCA) and FL were the most specific for it. FC and FL were the most sensitive and specific tests, respectively, to distinguish IBD from irritable bowel syndrome (IBS). Anti-Saccharomyces cerevisiae antibodies (ASCA), IgA, were the best test to distinguish Crohn's disease (CD) from ulcerative colitis (UC). Interferon-γ release assay was the best test to distinguish CD from intestinal tuberculosis (ITB). Ultrasound (US) and magnetic resonance enterography (MRE) were both sensitive and specific for disease activity, along with the high sensitivity of FC. Small intestine contrast ultrasonography (SICUS) had the highest sensitivity, and FC had the highest specificity for operative CD recurrence.

CONCLUSION

In this umbrella review, we summarized the diagnostic performance of non-invasive tests for IBD in various clinical conditions and age groups. Clinicians can use the suggested non-invasive test depending on the appropriate clinical situation in IBD patients.

A Patient Self-Made Point-of-Care Fecal Test Improves Diagnostic Accuracy Compared with Fecal Calprotectin Alone in Inflammatory Bowel Disease Patients

Background: Monitoring inflammatory bowel disease patients may be challenging. Fecal calprotectin is one of the most performed tests. Other fecal biomarkers are less used in clinical practice. Rapid fecal tests that could be performed by patients may be a useful strategy to closely monitor disease activity. Methods: We performed a prospective observational study including consecutive inflammatory bowel disease patients referred for colonoscopy in a single center. Certest FOB + Transferrin + Calprotectin + Lactoferrin^® (Certest Biotec S.L, Zaragoza, Spain), a one-step point-of-care test which simultaneously detects these four biomarkers was performed. Endoscopic inflammatory activity was defined using the Mayo score (≥1) in ulcerative colitis, SES-CD (>3) and Rutgeerts scores (≥1) for Crohn’s disease. Results: Out of a total of 106 patients (56.5% female, mean age 51 years), 54 (50.9%) were diagnosed with ulcerative colitis and 52 (49.1%) with Crohn’s disease. Endoscopic activity was detected in 42 patients (39.0%). Fecal calprotectin provided the best sensitivity (97.6%), with limited specificity (34.4%). Compared to calprotectin, the other 3 fecal biomarkers showed better specificity (87.5–92.1%) and lower sensitivity (45.2–59.5%). Patients with a negative result in all biomarkers (19/106—17.9%) had 100% (CI 95% 97.4–100) negative predictive value, while patients with the 4 biomarkers positive (13/106—12.3%) had 100% (CI 95% 96.1–100) positive predictive value of endoscopic inflammatory activity. AUROC of this 4 biomarker point-of-care test was 0.845 (95% CI 0.771–0.920), significantly higher than the AUROCs of any of the 4 biomarkers. Conclusions: This test may be a useful strategy to monitor inflammatory activity in clinical practice by excluding or prioritizing patients in need of a colonoscopy.

Fecal Lactoferrin and Other Putative Fecal Biomarkers in Crohn's Disease: Do They Still Have a Potential Clinical Role?

INTRODUCTION

The need for noninvasive markers of disease activity is mandatory in the assessment of Crohn's disease (CD). The most widely fecal biomarker in CD, despite several limits, is fecal calprotectin. This review aims to elucidate the role, if any, of all other fecal biomarkers, as alternative tools for assessing clinical and endoscopic disease activity, and predict capsule endoscopy findings, response to therapy, disease relapse, and postoperative recurrence. These fecal biomarkers included lactoferrin, S100A12, high mobility group box 1, neopterin, polymorphonuclear neutrophil elastase, fecal hemoglobin, alpha1-antitrypsin, lysozyme, human beta-defensin-2, neutrophil gelatinase-associated lipocalin, matrix metalloproteinase-9, chitinase 3-like-1, M2-pyruvate kinase, myeloperoxidase, and eosinophil proteins.

METHODS

A systematic electronic search in the medical literature was performed up to April 2020. Seventy eligible studies were identified out of 859 citations. Data were grouped according to the assessment of clinical and endoscopic disease activity, capsule endoscopy findings, response to therapy, prediction of relapse, and postoperative recurrence.

RESULTS

The overall correlation between lactoferrin and clinical indexes is poor, while performance is good with endoscopic scores. Lactoferrin seems to represent a reasonably good surrogate marker of response to therapy and to be potentially useful in identifying patients at high risk for endoscopic relapse or postoperative recurrence. The evaluation of the performance of all other fecal markers is limited by the lack of adequate data.

CONCLUSIONS

None of the fecal markers so far represents an acceptable alternative to calprotectin in clinical practice. Fecal lactoferrin is the only possible exception, but a more extensive investigation is still required.

Fecal Lactoferrin Predicts Primary Nonresponse to Biologic Agents in Inflammatory Bowel Disease

INTRODUCTION

Fecal lactoferrin (FL) is a timely and accurate marker of inflammation in ulcerative colitis (UC) and Crohn's disease (CD). The aim of this study was to verify whether FL can predict primary nonresponse (PNR) to biologic agents during induction.

METHODS

Retrospective outcome review in 27 patients (13 with CD and 14 with UC) tested for baseline FL and retested within a week after the first and second induction doses. Clinical/biochemical outcomes were evaluated at end of induction and at follow-up (3-24 months).

RESULTS

Compared to baseline, changes of the Harvey-Bradshaw (CD) and Partial Mayo Scoring (UC) indices at end of induction separated responders (18/27 or 67%) from nonresponders (9/17 or 33%). In all patients, the initial FL value at induction decreased compared to baseline, continuing to decrease after the following dose in clinical responders while bouncing back in the others. Models targeting the 2 consecutively decreased FL values or the second FL value compared to baseline or the second FL value compared to the first were able to accurately predict response at end of induction. Follow-up assessment confirmed clinical remission in initial responders (with FL values reduced on the average by 94 ± 10% compared to baseline).

CONCLUSIONS

In CD and UC patients during induction with biologic agents, early FL measurements accurately separate clinical responders from those experiencing PNR. The method described here offers several potential advantages over other strategies to assess and manage these patients.

Timely Monitoring of Inflammation by Fecal Lactoferrin Rapidly Predicts Therapeutic Response in Inflammatory Bowel Disease

BACKGROUND

Fecal lactoferrin (FL) levels may mirror drug-induced changes in inflammation in ulcerative colitis and Crohn disease in a timely way and could be used to assess loss of response (LOR) to biologics.

METHODS

This study is a retrospective outcome review in 61 patients on adalimumab, infliximab, or vedolizumab managed in our center and followed for 6 to 24 months. Patients were 1) in clinical remission or 2) were experiencing possible LOR.

RESULTS

For group 1, in 71% of 31 patients, FL slowly increased during the therapeutic interval (R2 = 0.769; P < 0.001), thus reflecting increasing inflammation as drug concentrations decreased. In the remaining patients, FL was undetectable throughout the therapeutic interval because of a stronger suppression of inflammation. For group 2, in 30 patients negative for infections, FL levels measured 1 to 3 days after infusion/injection compared to preadministration values either increased (nonresponders)-in these patients the medication was switched to another class; partially decreased (partial responders)-the therapeutic interval was shortened; or were normal throughout (responders)-causes for symptoms unrelated to disease activity were found for all. After FL-based management, 3-month standardized clinical scores were normalized in both partial responders (0.58 ± 0.21 vs 0.13 ± 0.09; P < 0.001) and nonresponders (0.81 ± 0.17 vs 0.12 ± 0.08; P < 0.001), and FL levels dropped by up to 99%.

CONCLUSIONS

Levels of FL reflect drug-induced changes in mucosal inflammation in a timely way, thus enabling rapid assessment of therapeutic response in patients with ulcerative colitis and with Crohn disease. In patients with suspected LOR, FL levels before and after infusion/injection accurately separated responders, partial responders, and nonresponders. The strategy proposed here is simple, accurate, and easily applicable to clinical practice.

Lactoferrin and Its Detection Methods: A Review

Lactoferrin (LF) is one of the major functional proteins in maintaining human health due to its antioxidant, antibacterial, antiviral, and anti-inflammatory activities. Abnormal levels of LF in the human body are related to some serious diseases, such as inflammatory bowel disease, Alzheimer’s disease and dry eye disease. Recent studies indicate that LF can be used as a biomarker for diagnosis of these diseases. Many methods have been developed to detect the level of LF. In this review, the biofunctions of LF and its potential to work as a biomarker are introduced. In addition, the current methods of detecting lactoferrin have been presented and discussed. We hope that this review will inspire efforts in the development of new sensing systems for LF detection.

Fibrotic Strictures in Crohn's Disease: Mechanisms and Predictive Factors

Fibrotic strictures are one of the most severe complications of Crohn's Disease (CD). They occur in about 50% of patients at five years and in 70% at ten years of the diagnosis. The only treatment available for symptomatic fibrotic strictures is surgical resection and endoscopic dilation. Both strategies are associated with a high rate of recurrence, and with multiple surgical resections, which pose the threat of surgical morbidity and short bowel syndrome. Therefore, it is crucial to identify, early, the patients more prone to develop intestinal fibrosis to intensify follow-ups, switch to more aggressive treatments, and suggest lifestyle modifications. Scarce data are available concerning biomarkers and genetic determinants to predict which patient will develop intestinal fibrosis. Biologic or clinical markers would be useful to determine this subgroup of CD patients and to predict the onset of intestinal fibrosis and, ideally, its severity. Furthermore, the identification of environmental risk factors may suggest lifestyle changes aimed at modifying the natural course, thus decreasing the risk of complicated CD. In this review, we will critically revise clinical, environmental, genetic, and serologic factors that have been associated with a complicated CD course with a particular focus on the fibrostenosing phenotype and their possible implications as predictive factors of intestinal fibrosis.

Fecal Lactoferrin and Other Stool Markers during Normal Pregnancy and in Inflammatory Bowel Diseases: A Prospective Study and Review of the Literature

Introduction

Management of inflammatory bowel diseases (IBDs) - both Crohn's disease (CD) and ulcerative colitis (UC) - during pregnancy can be challenging since most monitoring tools available in nonpregnant patients are contraindicated.

Objectives

The aim of the study was to test whether fecal inflammatory markers - specifically fecal lactoferrin - physiologically change during normal pregnancy as a prerequisite to use them to monitor IBD activity during pregnancy.

Methods

Fecal lactoferrin was tested in healthy pregnant and nonpregnant women from the same geographic area and age range (18-40 years) - all negative for clinical gastrointestinal tract inflammation. A retrospective review of fecal lactoferrin levels contrasted with the Simple Endoscopic Score for CD, and the Disease Activity Index for UC was also performed in women with active IBDs within the same age range and geographical area.

Results

In 30 nonpregnant subjects, fecal lactoferrin levels were 0.87 ± 1.08 μg/g. In 49 pregnant subjects, levels were 0.59 ± 0.83, 0.87 ± 1.13, and 0.85 ± 1.06 μg/g during the first, second, and third trimester, respectively (p = 0.64), with average levels for the 3 trimesters of 0.81 ± 1.04 μg/g (p = 0.61 compared to nonpregnant subjects). Sequential fecal lactoferrin levels (n = 26) did not differ from one trimester to the other in the individual subjects (p = 0.80). In 45 female IBD patients (27 with CD and 18 with UC), fecal lactoferrin levels were correlated with disease activity as defined by the endoscopic scores: 218, 688, and 1,175 μg/g for CD and 931, 2,088, and 2,509 μg/g for UC, respectively, for mild, moderate, and severe activity.

Conclusions

Fecal lactoferrin levels during normal pregnancy are superimposable to those of nonpregnant women and significantly below levels in women of the same childbearing age with active IBDs. Additional published data - reviewed in this atricle - and our own indicate that fecal lactoferrin and other markers can be potentially used to monitor disease activity in pregnant IBD patients.

Biomarkers of Inflammation in Inflammatory Bowel Disease: How Long before Abandoning Single-Marker Approaches?

BACKGROUND

Inflammatory bowel disease (IBD) is a chronically relapsing disease with a continuous need for proactive monitoring to decide appropriate treatments and follow-up strategies. To date, gastrointestinal endoscopy with histologic examination of biopsies and contrast-enhanced imaging are mandatory techniques for the diagnosis and the activity assessment of IBD.

SUMMARY

In recent decades, many research efforts in the IBD field have been placed on finding non-invasive and reliable biomarkers of disease burden that can be easily tested in body fluids without impacting the quality of life of patients. Unfortunately, the ideal biomarker is yet to be discovered and recent studies have investigated the possibility to increase the accuracy of such measurements by combining different markers. In this review, we provide an update about the current knowledge on biomarkers of intestinal inflammation in IBD, focussing on disease diagnosis, correlation with endoscopic findings, and prediction of relapse. We also summarize composite scores of clinical and laboratory markers that have been recently proposed in various scenarios of disease activity. Key Messages: To date, only C-reactive protein and faecal calprotectin can be considered reliable markers of disease activity with demonstrated utility in IBD management. The combination of different parameters has recently shown higher accuracy and might substitute single-marker approaches in the future of research and clinical practice.

Comparison of 18F-FDG PET-MR and fecal biomarkers in the assessment of disease activity in patients with ulcerative colitis

OBJECTIVE

To compare the diagnostic performance of fecal biomarkers and ¹⁸F-fludeoxyglucose (¹⁸F-FDG) positron emmision tomography-MR (PET-MR) in the assessment of disease activity in patients with ulcerative colitis.

METHODS

This study was conducted under the framework of a single-center clinical trial (clinicaltrials.gov [NCT03781284]). N = 50 participants were enrolled. Fecal samples were collected before bowel preparation. All patients underwent whole-body ¹⁸F-FDG PET-MR followed by ileocolonoscopy within 24 h. Diagnostic performance of five fecal biomarkers (calprotectin, lactoferrin, polymorphonuclear leukocyte elastase, S100A12 and eosinophil-derived neurotoxin), MR morphological parameters (MRmorph), diffusion-weighted imaging and PET in detecting active disease determined by Rachmilewitz endoscopic activity index (EAI) were evaluated and compared with each other. Correlations between fecal biomarkers, PET and endoscopy were calculated.

RESULTS

According to EAI, n = 38 patients presented with endoscopically active disease (16 mild, 19 moderate and 3 severe). All five biomarkers, PET and MRmorph could differentiate endoscopically active disease from endoscopic remission without significant difference regarding their operating characteristics (accuracies between 0.673 for calprotectin and 0.898 for lactoferrin). In predicting endoscopically moderate to severe disease, PET showed the highest diagnostic performance (accuracy = 0.857) compared to calprotectin and lactoferrin (accuracy = 0.633 and 0.735). PET had also the strongest correlation with endoscopy (ρ = 0.685, p < 0.001), while within fecal biomarkers the levels of lactoferrin and eosinophil-derived neurotoxin correlated significantly with EAI (ρ = 0.423 and 0.528, both p < 0.05).

CONCLUSION

Both fecal biomarkers and PET-MR were excellent non-invasive diagnostic tools in the assessment of disease activity in ulcerative colitis.

ADVANCES IN KNOWLEDGE

Both fecal biomarkers and PET-MR parameters are able to predict endoscopically active disease with comparable diagnostic performance. PET had the highest correlation with endoscopy and outperformed fecal biomarkers in differentiating moderate to severe from mild disease.

Fecal lactoferrin accurately reflects mucosal inflammation in inflammatory bowel disease

BACKGROUND

Studies have demonstrated a potential role for fecal biomarkers such as fecal calprotectin (FC) and fecal lactoferrin (FL) in monitoring inflammatory bowel diseases (IBD) - Crohn’s disease (CD) and ulcerative colitis (UC). However, their correlation to endoscopic scores, disease severity and affected intestinal surface has not been extensively investigated.

AIM

To correlate FL, and for comparison white blood cell (WBC) and C-reactive protein (CRP), with endoscopic scores, disease extent and location in CD and UC.

METHODS

Retrospective analysis in 188 patients who had FL, CRP and WBC determined within 30 d of endoscopy. Disease location, disease extent (number of intestinal segments involved), disease severity (determined by endoscopic scores), timing of FL testing in relation to colonoscopy, as well as the use of effective fast acting medications (steroids and biologics) between colonoscopy and FL measurement, were recorded.

RESULTS

In 131 CD and 57 UC patients, both CRP and FL - but not WBC - distinguished disease severity (inactive, mild, moderate, severe). In patients receiving fast-acting (steroids or biologics) treatment in between FL and colonoscopy, FL showed a higher correlation to endoscopic scores when tested before vs after the procedure (r = 0.596, P < 0.001, vs r = 0.285, P = 0.15 for the Simple Endoscopic Score for CD; and r = 0.402, P = 0.01 vs r = 0.054 P = 0.84 for Disease Activity Index). Finally, FL was significantly correlated with the diseased mucosal surface (colon-ileocolon > small bowel) and the number of inflamed colon segments.

CONCLUSION

FL and CRP separated disease severity categories with FL showing lower discriminating P-values. FL showed a close correlation with the involved mucosal surface and with disease extent and was more closely correlated to endoscopy when determined before the procedure – this indicating that inflammatory activity changes associated with therapy might be rapidly reflected by FL levels. FL can accurately and timely characterize intestinal inflammation in IBD.