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.

Association between intestinal bacterial carriage, biomarkers of environmental enteric dysfunction and stunting in rural Malawian children

BackgroundGut bacteria Bifidobacterium longum, Faecalibacterium prausnitzii, Dorea formicigenerans and Akkermansia muciniphila have been implicated in mediation of growth. We investigate the prevalence of these four species, levels of fecal biomarkers of environmental enteric dysfunction (EED) and association with stunting in rural Malawian children. Methods DNA and protein were extracted from fecal samples of 613 children (aged 1-59 months) at a baseline cross-sectional survey in the Mangochi district of Malawi conducted within the framework of the MORDOR (Macrolides Oraux pour Réduire les Décès avec un Oeil sur la Résistance) trial. Intestinal carriage of bacteria was measured by PCR. Neopterin, myeloperoxidase and alpha-1 antitrypsin, biomarkers of EED, were measured by ELISA. Height-for-age Z (HAZ) score <-2 defined stunting. Tests of proportions and regression models were used to explore the relationship between bacterial carriage, EED and stunting.Results B. longum carriage in younger children was associated with elevated EED biomarkers. Two thirds of children had elevated NEO, 33% elevated MPO and 16% elevated AAT. Stunting was found in 38% of the children. No significant associations were found between EED biomarkers or intestinal bacteria carriage and stunting.

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

<b><i>Introduction:</i></b> 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. <b><i>Methods:</i></b> 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. <b><i>Results:</i></b> 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. <b><i>Conclusions:</i></b> 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.

Lipocalin-2 and calprotectin as stool biomarkers for predicting necrotizing enterocolitis in premature neonates

Background Necrotizing enterocolitis (NEC) is a major challenge for premature infants in neonatal intensive care units and efforts toward the search for indicators that could be used to predict the development of the disease have given limited results until now. Methods In this study, stools from 132 very low birth weight infants were collected daily in the context of a multi-center prospective study aimed at investigating the potential of fecal biomarkers for NEC prediction. Eight infants (~6%) received a stage 3 NEC diagnosis. Their stools collected up to 10 days before diagnosis were included and matched with 14 non-NEC controls and tested by ELISA for the quantitation of eight biomarkers. Results Biomarkers were evaluated in all available stool samples leading to the identification of lipocalin-2 and calprotectin as the two most reliable predicting markers over the 10-day period prior to NEC development. Pooling the data for each infant confirmed the significance of lipocalin-2 and calprotectin, individually and in combination 1 week in advance of the NEC clinical diagnosis. Conclusions The lipocalin-2 and calprotectin tandem represents a significant biomarker signature for predicting NEC development. Although not yet fulfilling the “perfect biomarker” criteria, it represents a first step toward it. Impact Stool biomarkers can be used to predict NEC development in very low birth weight infants more than a week before the diagnosis. LCN2 was identified as a new robust biomarker for predicting NEC development, which used in conjunction with CALPRO, allows the identification of more than half of the cases that will develop NEC in very low birth weight infants. Combining more stool markers with the LCN2/CALPRO tandem such as PGE2 can further improve the algorithm for the prediction of NEC development.

C-reactive protein is superior to fecal biomarkers for evaluating colon-wide active inflammation in ulcerative colitis

We evaluated the association between endoscopic scores of colonic inflammation and fecal calprotectin (FC), fecal immunochemical occult blood test (FIT), and C-reactive protein (CRP) in patients with ulcerative colitis (UC). Endoscopic scores reflecting the most severe lesion [maximum Mayo Endoscopic Subscore (M-MES) and Ulcerative Colitis Endoscopic Index of Severity (UCEIS)] and those reflecting the inflammation of the entire colon [sum of MES (S-MES) and Ulcerative Colitis Colonoscopic Index of Severity (UCCIS)] were evaluated. FC, FIT, and CRP were measured, and their association with the four endoscopic scores was evaluated. Endoscopic scores of 78 complete colonoscopies (66 UC patients) were evaluated using the three biomarkers. FC and CRP tended to correlate more strongly with S-MES and UCCIS than with M-MES and UCEIS. In the M-MES 0, 1 group, compared to CRP, FC and FIT showed stronger correlations with S-MES and UCCIS. Conversely, in the M-MES 2, 3 group, only CRP was significantly correlated with each descriptor. CRP more strongly reflects colon-wide mucosal inflammation than FC and allows reliable assessment of inflammation throughout the colon in active UC.

The Addition of Other Fecal Biomarkers Does Not Improve the Diagnostic Accuracy of Immunochemical Fecal Occult Blood Test Alone in a Colorrectal Cancer Screening Cohort

Background: Screening with fecal occult blood test reduces colorectal cancer (CRC) incidence and mortality, and is currently implemented in most countries. However, around 40% of screening colonoscopies are normal. Thus, strategies to avoid these colonoscopies are highly necessary. Adding other fecal biomarkers, such as fecal calprotectin (FC), lactoferrin, and transferrin may be useful, but evidence is scarce.Aims: To evaluate the diagnostic accuracy of fecal occult blood immunochemical test (FIT), FC, and a one-step combo card test for the simultaneous semi-qualitative detection of human hemoglobin (hHb), transferrin (hTf), calprotectin (hCp) and lactoferrin (hLf) in a CRC screening program population.Methods: Single-center, prospective observational study, enrolling patients included in a CRC screening program, referred for a colonoscopy due to a positive FIT test. Participants collected a stool sample prior to bowel preparation, and FIT, FC and the combo semi-qualitative tests were performed on the sample. Sensitivity, specificity, positive and negative predictive values and area under receiver operator curve (AUC) for diagnosis of advanced neoplasia, advanced adenoma and CRC were estimated for each biomarker and their combinations. The primary endpoint of the study was to assess whether these biomarkers could improve the diagnostic accuracy of FIT alone.Results: 336 consecutive patients (64% males) were recruited. Advanced neoplasia was found in 129/336 (38.4%) patients, and of these, 22/336 (6.5%) were diagnosed of CRC. 153/336 (45.5%) colonoscopies were completely normal. The AUC for the diagnosis of advanced neoplasia were 0.725 (95%CI 0.665–0.784) for FIT, 0.477 (95%CI 0.413–0.541) for FC and 0.732 (95%CI 0.674–0.791) for the combination of both (FIT + FC) quantitative tests. The AUCs for the combo test were 0.70 (95%CI 0.641–0.760) for hHb, 0.625 (95%CI 0.562–0.698) for hTf, 0.532 (95%CI 0.469–0.595) for hCp, 0.531 (95%CI 0.466–0.595 ) for hLf and 0.681 (95%CI 0.620–0.741) for the combination of the four biomarkers.Conclusion: In average-risk population, FIT appears to be the best fecal marker for the diagnosis of CRC and advanced adenoma. None of the other biomarkers explored or their combinations provided a better diagnostic accuracy. Only hTF showed an acceptable diagnostic accuracy. FC and hLF were not useful in this setting.

P052 Comprehensive proteomic profiling of stool from UC and CD patients reveals expected and novel mucosal pathobiology, enabling identification of candidate non-invasive biomarkers to monitor mucosal disease activity

Background Inflammatory bowel disease (IBD) is a multifactorial disorder characterized by chronic gastrointestinal (GI) inflammation. In clinical practice, physicians urgently need biomarkers to monitor changes in mucosal disease to manage treatment. Non-invasive tools such as fecal biomarkers could allow for frequent monitoring of mucosal disease activity and may reflect inflammation of the entire GI tract. Towards identification of novel non-invasive fecal biomarkers, we performed a comprehensive, unbiased, analysis of the human fecal proteome from ulcerative colitis (UC), Crohn’s disease (CD) patients, and healthy controls (HC), focusing on human secreted proteins using proteomic approaches. Methods Fecal extraction processes optimized for recovery of secreted proteins were applied to stool samples of mild to severe UC and CD patients and HCs, 20 samples per group. An unbiased survey of the human fecal proteome of the IBD and HC stool extracts was performed using both data-dependent acquisition and data-independent acquisition methods on QExactive HF and Fusion Lumos mass spectrometers. Data were analyzed in Spectronaut for peptide identification, followed by analysis in MS Stats for protein quantification. Fecal calprotectin (fCAL) levels were measured in these stool samples using the Buhlmann EK-CAL immunoassay kit to correlate fCAL levels to proteomic calprotectin (S100A8/S100A9 heterodimer). Results We identified and quantified 594 differentially expressed proteins in stool using proteomics, including known proteins perturbed in IBD pathobiology. Elevated levels of neutrophilic proteins, e.g. fCal, neutrophil elastase, lactoferrin and leucine-rich Α-2 glycoprotein 1 were detected as well as proteins linked to rectal bleeding and ulceration e.g. hemoglobin subunit alpha 1 and beta. Pancreatic enzymes, suggested to be associated with active disease, were also detected. Overall, UC and CD contained many proteins not detected in HC. Differential abundances were observed between UC and CD patients, possibly reflecting differences in mucosal pathophysiology. The abundance of proteomic calprotectin correlated highly with the fCAL levels as determined by immunoassay (Spearman rank order &gt; 0.9 for S100A8 and S100A9 to fCAL), validating the fecal proteomic approach to uncover known and novel proteins of IBD biology. Conclusion We developed and qualified methods to perform fecal proteomics on IBD stool samples, enabling identification of known and novel proteins of mucosal UC and CD disease biology. In depth analysis of these proteomic datasets may reveal novel fecal biomarker candidates, targeted to reflect mucosal disease activity and potentially serve as non-invasive surrogates for endoscopy and help guide treatment in IBD patients.

Extent of disease affects the usefulness of fecal biomarkers in ulcerative colitis

Background Fecal biomarkers are considered to be useful surrogate markers for endoscopic activity. Given the mechanisms of fecal biomarkers, we hypothesized that the extent of ulcerative colitis (UC; pancolitis, left-sided colitis, and proctitis) could affect the usefulness of fecal biomarkers for assessing endoscopic and clinical disease activity; however, few studies have evaluated the utility of fecal biomarkers in the disease extent of UC. Methods Fecal calprotectin, a fecal immunochemical test for hemoglobin, and fecal lactoferrin were used as fecal biomarkers. UC patients, who underwent colonoscopy within 30 days of the fecal biomarker test, participated in this observational study. Clinical and endoscopic disease activity was assessed using the Lichtiger Index and Mayo endoscopic subscore (MES), respectively. Results A total of 162 colonoscopies were performed on 133 UC patients. A correlation analysis between each biomarker and the MES for each disease-extent subgroup showed a decreased correlation in the proctitis compared with the other groups. With the exception of proctitis, it was possible to distinguish between MES 0 and MES ≥ 1 with high area-under-the-curve values for fecal calprotectin and fecal lactoferrin. The fecal immunochemical test for hemoglobin was superior at discriminating MES 0 for proctitis. Conclusions For the practical application of fecal biomarkers for UC patients, it is necessary to consider disease extent before use. In particular, patients with proctitis exhibit a low correlation between stool biomarkers and endoscopic findings. The usefulness of these biomarkers for endoscopic remission is reduced, except for the fecal immunochemical test for hemoglobin.