Calprotectin as a new inflammatory marker of abdominal aortic aneurysm: A pilot study

INTRODUCTION

Abdominal aortic aneurysm (AAA) is a relevant clinical problem due to the risk of rupture of progressively dilated infrarenal aorta. It is characterized by degradation of elastic fibers, extracellular matrix, and inflammation of the arterial wall. Though neutrophil infiltration is a known feature of AAA, markers of neutrophil activation are scarcely analyzed; hence, the main objective of this study.

METHODS

Plasma levels of main neutrophil activation markers were quantified in patients with AAA and a double control group (CTL) formed by healthy volunteers (HV) and patients with severe atherosclerosis submitted for carotid endarterectomy (CE). Calprotectin, a cytoplasmic neutrophil protein, was quantified, by Western blot, in arterial tissue samples from patients with AAA and organ donors. Colocalization of calprotectin and neutrophil elastase was assessed by immunofluorescence.

RESULTS

Plasma calprotectin and IL-6 were both elevated in patients with AAA compared with CTL (p ⩽ 0.0001) and a strong correlation was found between both molecules (p < 0.001). This difference was maintained when comparing with HV and CE for calprotectin but only with HV for IL-6. Calprotectin was also elevated in arterial tissue samples from patients with AAA compared with organ donors (p < 0.0001), and colocalized with neutrophils in the arterial wall.

CONCLUSIONS

Circulating calprotectin could be a specific AAA marker and a potential therapeutical target. Calprotectin is related to inflammation and neutrophil activation in arterial wall and independent of other atherosclerotic events.

Values of serum intestinal fatty acid-binding protein, fecal calprotectin, and fecal human β-defensin 2 for predicting necrotizing enterocolitis

BACKGROUND

This study aimed to assess the diagnostic potential of serum intestinal fatty acid-binding protein (I-FABP), fecal calprotectin (FC), and fecal human β-defensin 2 (hBD2) in predicting necrotizing enterocolitis (NEC) in preterm infants.

METHODS

A prospective cohort of neonates with a gestational age < 32 weeks, suspected of NEC, was enrolled between June 2021 and December 2022. Serum I-FABP, FC, and fecal hBD2 levels were measured upon NEC suspicion, and diagnosis was confirmed through radiological examination or surgical intervention. Diagnostic precision of serum I-FABP, FC, and fecal hBD2 was assessed using a logistic regression model with multiple variables.

RESULTS

The study included 70 neonates (45 males, 25 females), with 30 developing NEC (40% Stage III, n = 12; 60% Stage II, n = 18) and 40 in the control group. NEC patients exhibited significantly higher serum I-FABP and FC levels (4.76 ng/mL and 521.56 µg/g feces, respectively) than those with other diagnoses (1.38 ng/mL and 213.34 µg/g feces, respectively; p ˂ 0.05 for both biomarkers). Stage II NEC neonates showed elevated fecal hBD2 levels (376.44 ng/g feces) than Stage III NEC neonates and controls (336.87 ng/g and 339.86 ng/g feces, respectively; p ˂ 0.05). No such increase was observed in infants progressing to Stage III NEC. Using a serum I-FABP threshold of > 2.54 ng/mL yielded 76.7% sensitivity, 87.5% specificity, 82.1% positive predictive value (PPV), and 83.3% negative predictive value (NPV). For FC (cutoff > 428.99 µg/g feces), corresponding values were 76.7% sensitivity, 67.5% specificity, 63.9% PPV, and 79.4% NPV.

CONCLUSION

Serum I-FABP and FC levels are valuable for early NEC detection and provide insights into disease severity. Low fecal hBD2 levels suggest an inadequate response to luminal bacteria, potentially rendering these infants more susceptible to NEC development or exacerbation.

The gut-brain axis: Correlation of choroid plexus volume and permeability with inflammatory biomarkers in Crohn's disease

BACKGROUND

The dysregulation of the gut-brain axis in chronic inflammatory bowel diseases can cause neuro-psychological disturbances, but the underlying mechanisms are still not fully understood. The choroid plexus (CP) maintains brain homeostasis and nourishment through the secretion and clearance of cerebrospinal fluid. Recent research has demonstrated the existence of a CP vascular barrier in mice which is modulated during intestinal inflammation. This study investigates possible correlations between CP modifications and inflammatory activity in patients with Crohn's disease (CD).

METHODS

In this prospective study, 17 patients with CD underwent concomitant abdominal and brain 3 T MRI. The volume and permeability of CP were compared with levels of C-reactive protein (CRP), fecal calprotectin (FC), sMARIA and SES-CD scores.

RESULTS

The CP volume was negatively correlated with CRP levels (R = -0.643, p-value = 0.024) and FC (R = -0.571, p-value = 0.050). DCE metrics normalized by CP volume were positively correlated with CRP (K-trans: R = 0.587, p-value = 0.045; Vp: R = 0.706, p-value = 0.010; T1: R = 0.699, p-value = 0.011), and FC (Vp: R = 0.606, p-value = 0.037).

CONCLUSIONS

Inflammatory activity in patients with CD is associated with changes in CP volume and permeability, thus supporting the hypothesis that intestinal inflammation could affect the brain through the modulation of CP vascular barrier also in humans.

Iron Sequestration by Murine Calprotectin Induces Starvation Responses in Pseudomonas aeruginosa

Pathogen sensing by the mammalian host induces a pro-inflammatory response that involves release of the antimicrobial metal-sequestering protein calprotectin (CP, S100A8/S100A9 heterooligomer, MRP8/MRP14 heterooligomer) from neutrophils. Biochemical investigations on human CP (hCP) have informed the molecular basis of how this protein sequesters metal ions. Murine models of infection have provided invaluable insights into the ability of murine CP (mCP) to compete with bacterial pathogens for essential metal nutrients. Despite this extensive work, our knowledge of how mCP sequesters metals from bacterial pathogens and its impacts on bacterial physiology is limited. Moreover, whether mCP sequesters iron and induces iron-starvation responses in bacterial pathogens has not been evaluated. Here, we examine the ability of mCP to withhold iron from Pseudomonas aeruginosa, a Gram-negative opportunistic pathogen that causes severe infections in immunocompromised individuals and cystic fibrosis patients. We demonstrate that mCP prevents iron uptake and induces iron-starvation responses in P. aeruginosa laboratory strains PA14 and PAO1 and the JSRI-1 clinical isolate from a cystic fibrosis patient. We also show that mCP prevents iron uptake and induces an iron-starvation response in the Gram-positive bacterial pathogen Staphylococcus aureus. The His6 site of mCP is the iron-sequestering site; it exhibits Ca(II)-dependent Fe(II) affinity and binds Fe(II) with subpicomolar affinity in the presence of excess Ca(II) ions. This work is important for understanding the structure, function, and physiological consequences of mCP and how the mammalian host and bacterial pathogens compete for essential metal nutrients.

Spectroscopic and computational investigations of Cobalt(II) binding to the innate immune protein human calprotectin

Human calprotectin (CP) is an innate immune protein that participates in the metal-withholding response to infection by sequestering essential metal nutrients from invading microbial pathogens. CP is comprised of S100A8 (α subunit, 10.8 kDa) and S100A9 (β subunit, 13.2 kDa). Two transition-metal binding sites of CP form at the S100A8/S100A9 dimer interface. Site 1 is a His3Asp motif comprised of His83 and His87 from the S100A8 subunit and His20 and Asp30 from the S100A9 subunit. Site 2 is an unusual hexahistidine motif composed of S100A8 residues His17 and His27 and S100A9 residues His91, His95, His103, and His105. In the present study, the His3Asp and His6 sites of CP were further characterized by utilizing Co2+ as a spectroscopic probe. Magnetic circular dichroism spectroscopy was employed in conjunction with electron paramagnetic resonance spectroscopy and density functional theory computations to characterize the Co2+-bound S100A8(C42S)/S100A9(C3S) CP-Ser variant and six site variants that allowed the His3Asp and His6 sites to be further probed. Our results provide new insight into the metal-binding sites of CP-Ser and the effect of amino acid substitutions on the structure of site 2.

Role of Calprotectin, IL-6, and CRP in Distinguishing Between Inflammatory Bowel Disease and Diarrhea Predominant Irritable Bowel Syndrome

Background

The early establishment of prophylaxis and immediate administration of anticoagulant therapy upon the diagnosis of venous thromboembolism should be the treatment objectives in these patients.

Objective

The study aimed to determine the optimal cut-off point of Calprotectin, IL-6 (interleukin-6), CRP (C reactive protein) to differentiate UC, IBS-D.

Methods

A cross-sectional descriptive study of 335 individuals ≥15 years old was performed, including 31 healthy controls, 215 with IBS-D, 71 diagnosed with UC, and 18 diagnosed with CD. Receiver Operating Characteristics (ROC), sensitivity, specificity, and area under curve (AUC) were computed.

Results

The results showed that the median value of calprotectin (IQR) in healthy participants was 20.0 (6.0 - 34.0) µg/g; 17,7 (8,7-38,9) µg/g in IBS-D group; 1710.0 (588 - 4260,0) µg/g in UC group; and 560.5 (177.8 - 1210.0) µg/g in CD group. Calprotectin concentration in IBD group including UC and CD was higher than IBS-D with p<0.05. The median value of CRP (range IQR) was 1,3 (0,9 - 2,3) mg/L in IBS-D group; 7.0 (2.4 -16.6) mg/L in UC group; and 10.1 (2.2 - 42.5) mg/L in CD group. CRP concentration in IBD group including UC and CD was higher than IBS-D with p<0.05. The median value of IL-6 (range IQR) was 2.3 (1.6 - 5.7) pg/mL in IBS-D group; 16.8 (9.4 - 47.0) pg/mL in UC group; and 9.4 (7.9 - 11.0) pg/mL in CD group. Calprotectin concentration in IBD group including UC and CD was higher than IBS-D with p<0.05. The optimal cut-off point of calprotectin that differentiated IBS-D from IBD was 110.5 µg/g, with sensitivity and specificity of 93.3% and 91.4%, respectively; of IL-6 was 7.2 pg/mL with sensitivity and specificity of 92.0% and 78.0%, respectively; of CRP of 2.4 mg/L had specific sensitivities of 83.3% and 86.0%, respectively.

Conclusion

The Calprotectin immunoassay has the best value in discriminating between IBD and IBS-D.

Assessing Active Bowel Inflammation in Crohn's Disease Using Intestinal Ultrasound: Correlation With Fecal Calprotectin

AIM

To analyze the correlation between intestinal ultrasound (IUS) and serum and fecal biomarkers, and the characteristics of small bowel disease, for the assessment of active bowel inflammation.

METHODS

Patients with Crohn's disease (CD) who underwent an initial IUS examination between July 2018 and November 2022 at our institution were included retrospectively. We divided small and large bowels into seven segments, and recorded the presence of active inflammation according to following criteria: bowel wall thickness ≥ mm with ≥1 of feature of active disease on IUS. The correlations between IUS-assessed activity and serum C-reactive protein (CRP, mg/dL) and fecal calprotectin (FC, μg/g) levels were analyzed.

RESULTS

A total of 127 patients were included (mean age: 32.42 ± 12.07, M:F = 90:37, median disease duration 6 years [0-35]). Of them, 78 showed active bowel inflammation (61.4%), with inflammation distal to the terminal ileum being the most common disease location (n = 61, 78.2%). FC and serum CRP levels were significantly correlated with the number of segments with active inflammation (rho = 0.58, 0.48), number of segments with complications (r = 0.35, 0.31), and US activity score (r = 0.62, 0.54). With FC cutoff values of 100 and 150 μg/g, the concordance rates for patients with active small bowel disease were 78.7% (26/33) and 72.7% (24/33), respectively, which were better than those for other disease locations.

CONCLUSIONS

Disease activity determined by IUS was significantly correlated with the biomarkers, with a better concordance rate in patients with active small bowel disease than in those with other disease locations with FC cut-off values of 100 and 150 μg/g.

Fecal calprotectin in patients with liver cirrhosis

BACKGROUND AND OBJECTIVES

Sepsis is the most challenging complication in patients with liver cirrhosis. It destabilizes patients leading to worsening of liver dysfunction and increased mortality. Intestinal bacterial dysbiosis, release of endotoxins, increased gut permeability and associated immune dysregulation have been described in cirrhotic patients with septic complications. Calprotectin is a major cytosolic protein secreted by the inflammatory cells and has been widely studied in patients with inflammatory bowel disease. We aimed at evaluating the role of fecal calprotectin (FCAL) in patients with liver cirrhosis.

METHODS

A prospective, observational study on the utility of FCAL test was conducted in patients with liver cirrhosis. Fifteen milligrams of fecal specimen was collected and analyzed within 48 hours of hospitalization from patients with end-stage liver disease (ESLD), acute-on-chronic liver failure (ACLF) and at the time of outpatient visit for stable cirrhotics. Five healthy volunteers underwent FCAL test as control population.

RESULTS

The mean FCAL (µg/g) level in healthy control (n = 5), stable cirrhotics (n = 10), ESLD (n = 10) and ACLF (n = 10) patients was 109.2 (95% CI: - 53.39 to 271.79), 143.3 (95% CI: 50.5-236.45), 176.9 (95% CI: 122.93-230.87) and 543.5 (95% CI: 207.09-879.91) (p = 0.005), respectively. Sepsis was identified in 13 (43.3%) patients. Area under the receiver-operating characteristics curve (AUROC) of FCAL was 0.80 (p = 0.005) and FCAL ≥ 200 µg/g (OR = 10.8, p = 0.006) was associated with sepsis. Nine (25.7%) patients expired. FCAL level was significantly higher in dead patients compared to survivors (mean, 493.67 (95% CI: 142.20-845.14) vs. 199.71 (95% CI: 99.84-299.59) μg/g,p = 0.005.

CONCLUSIONS

FCAL levels are increased in patients with chronic liver disease, with highest level in ACLF. An FCAL level of ≥ 200 µg/g was associated with sepsis and mortality in cirrhotic patients. Larger studies are required to identify the role of FCAL in these patients. Early identification and initiation of anti-microbials may mitigate sepsis and reduce mortality.

The IBD-FITT study - moderate-intensity exercise for patients with inflammatory bowel disease with moderate disease activity: an open-label randomized controlled trial

BACKGROUND

Inflammatory bowel disease (IBD), Crohn's disease, and ulcerative colitis are chronic autoimmune lifelong diseases with fluctuating activity over time. The treatment includes medical therapy and surgery, however, there is no definite cure. Therefore, the quest for new and supplementary treatment options is imperative to improve patients' general health and quality of life. Physical activity and exercise have been suggested to be elements in both the prevention and supplementary treatment of IBD; however, this is based on limited underpowered trials. Thus, the role of exercise as a treatment option still has to be settled. We aim to investigate the effect of a 12-week exercise intervention in adult patients with moderately active IBD on three categories of outcomes (1) disease-specific health-related quality of life (IBDQ); (2) general health status of the patients, i.e., waist circumference, disease activity by clinical scorings systems (Harvey Bradshaw Index, Simple Clinical Colitis Activity Index), blood pressure, blood lipids, and non-disease specific quality of life (EQ5D) scores; and (3) explorative outcomes on biomarkers (C-reactive protein and fecal calprotectin) plus different biomarkers of immunology (cytokine panel).

METHODS

We will apply a superiority design in this open-label randomized clinical trial including 150 patients equally allocated to intervention and usual care. The intervention will be based on a 12-week aerobic exercise program and will include two supervised exercise sessions of 60 min per week, combined with one weekly home training session. We have defined a moderate exercise level as 60-80% of patients' maximum heart rate. The patients in the intervention group will also be offered an online video lesson of 15-25 min on lifestyle guidance, and the same online video lesson will be offered in the comparator group. Questionnaires on quality of life will be forwarded electronically both at inclusion and at the end of the study, and the patients will have blood samples, and fecal samples for calprotectin at baseline, weeks 4 and 8, as well as after 12 weeks (study end).

DISCUSSION

This will be a clinical trial investigating the effect of exercise on patients with Crohn's disease and ulcerative colitis. This trial will add to the evidence on the possible effect of exercise and might clarify whether exercise can benefit as a supplementary treatment addendum. Thus, the trial may provide a new patient-active disease management approach.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04816812. Date of first registration: March 23, 2021.

Altered fecal bile acid composition in active ulcerative colitis

BACKGROUND

Disturbed bile acid homeostasis associated with a rise of primary and a decline of secondary bile acids is a consistent finding in inflammatory bowel diseases (IBDs). Whether fecal bile acids may emerge as biomarkers for IBD diagnosis and disease severity is less clear. Our study aimed to identify associations of 18 fecal bile acid species with IBD entity and disease activity.

METHODS

Stool samples of 62 IBD patients and 17 controls were collected. Eighteen fecal bile acid species were quantified by LC-MS/MS using stable isotope dilution. Lipid levels normalized to a dry weight of the fecal homogenates and ratios of single bile acid species to total bile acid levels were used for calculations.

RESULTS

IBD patients exhibited altered primary and secondary bile acid ratios in stool, with notable distinctions between ulcerative colitis (UC) compared to Crohn's disease (CD) and healthy controls. Fecal calprotectin was negatively correlated with glycolithocholic acid (GLCA) and hyodeoxycholic acid (HDCA) in UC. These bile acids were reduced in stool of UC patients with fecal calprotectin levels > 500 µg/g compared to UC patients with low calprotectin levels. Moreover, negative associations of six secondary bile acids with C-reactive protein (CRP) existed in UC. In CD patients, fecal bile acids did not correlate with CRP or fecal calprotectin. Diarrhoea is common in IBD, and UC patients with diarrhoea had reduced deoxycholic acid (DCA), glycine conjugated DCA (GDCA) and lithocholic acid in stool in contrast to patients with normal stool consistency. Fecal bile acid levels were not associated with diarrhoea in CD patients. UC patients treated with mesalazine had increased levels of fecal GDCA whereas no such changes were observed in CD patients. Bile acid levels of CD and UC patients treated with biologicals or corticosteroids did not change. Relative levels of GHDCA (specificity: 79%, sensitivity: 67%) and glycochenodeoxycholic acid (specificity: 74%, sensitivity: 63%) were the most specific to distinguish UC from CD.

CONCLUSION

Disrupted fecal bile acid homeostasis is associated with disease severity and disease symptoms in UC but not in CD, potentially aiding in distinguishing IBD subtypes and classifying the pathophysiology of diarrhoea in UC.

Gut inflammation associated with age and Alzheimer's disease pathology: a human cohort study

Age-related disease may be mediated by low levels of chronic inflammation ("inflammaging"). Recent work suggests that gut microbes can contribute to inflammation via degradation of the intestinal barrier. While aging and age-related diseases including Alzheimer's disease (AD) are linked to altered microbiome composition and higher levels of gut microbial components in systemic circulation, the role of intestinal inflammation remains unclear. To investigate whether greater gut inflammation is associated with advanced age and AD pathology, we assessed fecal samples from older adults to measure calprotectin, an established marker of intestinal inflammation which is elevated in diseases of gut barrier integrity. Multiple regression with maximum likelihood estimation and Satorra-Bentler corrections were used to test relationships between fecal calprotectin and clinical diagnosis, participant age, cerebrospinal fluid biomarkers of AD pathology, amyloid burden measured using 11C-Pittsburgh compound B positron emission tomography (PiB PET) imaging, and performance on cognitive tests measuring executive function and verbal learning and recall. Calprotectin levels were elevated in advanced age and were higher in participants diagnosed with amyloid-confirmed AD dementia. Additionally, among individuals with AD dementia, higher calprotectin was associated with greater amyloid burden as measured with PiB PET. Exploratory analyses indicated that calprotectin levels were also associated with cerebrospinal fluid markers of AD, and with lower verbal memory function even among cognitively unimpaired participants. Taken together, these findings suggest that intestinal inflammation is linked with brain pathology even in the earliest disease stages. Moreover, intestinal inflammation may exacerbate the progression toward AD.

Clostridioides difficile ferrosome organelles combat nutritional immunity

Iron is indispensable for almost all forms of life but toxic at elevated levels1-4. To survive within their hosts, bacterial pathogens have evolved iron uptake, storage and detoxification strategies to maintain iron homeostasis1,5,6. Recent studies showed that three Gram-negative environmental anaerobes produce iron-containing ferrosome granules7,8. However, it remains unclear whether ferrosomes are generated exclusively by Gram-negative bacteria. The Gram-positive bacterium Clostridioides difficile is the leading cause of nosocomial and antibiotic-associated infections in the USA9. Here we report that C. difficile undergoes an intracellular iron biomineralization process and stores iron in membrane-bound ferrosome organelles containing non-crystalline iron phosphate biominerals. We found that a membrane protein (FezA) and a P1B6-ATPase transporter (FezB), repressed by both iron and the ferric uptake regulator Fur, are required for ferrosome formation and play an important role in iron homeostasis during transition from iron deficiency to excess. Additionally, ferrosomes are often localized adjacent to cellular membranes as shown by cryo-electron tomography. Furthermore, using two mouse models of C. difficile infection, we demonstrated that the ferrosome system is activated in the inflamed gut to combat calprotectin-mediated iron sequestration and is important for bacterial colonization and survival during C. difficile infection.

Leucine-Rich Alpha-2 Glycoprotein Is a Reliable Serum Biomarker for Evaluating Clinical and Endoscopic Disease Activity in Inflammatory Bowel Disease

BACKGROUND

Leucine-rich alpha-2 glycoprotein (LRG) is a novel serum biomarker for inflammation in inflammatory bowel disease (IBD). This prospective study aimed to compare the value of LRG with C-reactive protein (CRP) and fecal calprotectin for evaluating clinical and endoscopic disease activity in patients with IBD.

METHODS

At entry, clinical and endoscopic disease activity was assessed in 267 patients with IBD (ulcerative colitis [UC] 203; Crohn's disease [CD] 64), and the levels of LRG, CRP and fecal calprotectin were measured. The accuracy of the biomarkers for the detection of clinical and endoscopic disease activity was determined by the area under the receiver operating characteristic curve.

RESULTS

Leucine-rich alpha-2 glycoprotein showed a significant relationship with the clinical and endoscopic severity in both UC and CD (both diseases, P < .0001). In the clinical assessment of UC, the accuracy of LRG was significantly higher than that of CRP (0.73 vs 0.63; P < .001). In the endoscopic assessment of UC, the accuracy of LRG was significantly higher than that of CRP (P = .01), but it was significantly lower than that of fecal calprotectin (P = .009; LRG, 0.80; CRP, 0.72; fecal calprotectin, 0.91). In the clinical and endoscopic assessment of CD, the accuracy was not significantly different between the biomarkers (clinical activity: LRG, 0.71; CRP, 0.64; fecal calprotectin, 0.66; in endoscopic activity: LRG, 0.79; CRP, 0.78; fecal calprotectin, 0.81).

CONCLUSIONS

Leucine-rich alpha-2 glycoprotein is a reliable serum biomarker for the assessment of clinical and endoscopic disease activity in patients with IBD. It can be an alternative to CRP for the assessment of UC.

Suboptimal Guideline Adherence and Biomarker Underutilization in Monitoring of Post-operative Crohn's Disease

BACKGROUND

Crohn's disease recurrence after ileocecal resection is common. Guidelines suggest colonoscopy within 6-12 months of surgery to assess for post-operative recurrence, but use of adjunctive monitoring is not protocolized. We aimed to describe the state of monitoring in post-operative Crohn's.

METHODS

We conducted a retrospective study of patients with Crohn's after ileocolic resection with ≥ 1-year follow-up. Patients were stratified into high and low risk based on guidelines. Post-operative biomarker (C-reactive protein, fecal calprotectin), cross-sectional imaging, and colonoscopy use were assessed. Biomarker, radiographic, and endoscopic post-operative recurrence were defined as elevated CRP/calprotectin, active inflammation on imaging, and Rutgeerts ≥ i2b, respectively. Data were stratified by surgery year to assess changes in practice patterns over time. P-values were calculated using Wilcoxon test and Fisher exact test.

RESULTS

Of 901 patients, 53% were female and 78% high risk. Median follow-up time was 60 m for LR and 50 m for high risk. Postoperatively, 18% low and 38% high risk had CRPs, 5% low and 10% high risk had calprotectins, and half of low and high risk had cross-sectional imaging. 29% low and 38% high risk had colonoscopy by 1 year. Compared to pre-2015, time to first radiography (584 days vs. 398 days) and colonoscopy (421 days vs. 296 days) were significantly shorter for high-risk post-2015 (P < 0.001). Probability of colonoscopy within 1 year increased over time (0.48, 2011 vs. 0.92, 2019).

CONCLUSION

Post-operative colonoscopy completion by 1 year is low. The use of CRP and imaging are common, whereas calprotectin is infrequently utilized. Practice patterns are shifting toward earlier monitoring.

Performance of fecal S100A12 as a novel non-invasive diagnostic biomarker for pediatric inflammatory bowel disease: a systematic review and meta-analysis

OBJECTIVE

The incidence and prevalence of inflammatory bowel disease (IBD) in pediatric patients are increasing. Currently, the diagnostic method for IBD is inconvenient, expensive, and difficult. S100A12, a type of calcium-binding protein, detected in the feces of patients with IBD has recently been suggested as a promising diagnostic tool. Hence, the authors aimed to evaluate the accuracy of fecal S100A12 in diagnosing IBD in pediatric patients by performing a meta-analysis.

METHODS

The authors performed a systematic literature search in five electronic databases for eligible studies up to July 15, 2021. Pooled diagnostic accuracies of fecal S100A12 were analyzed as the primary outcomes. Secondary outcomes were standardized mean difference (SMD) of fecal S100A12 levels between IBD and non-IBD groups and a comparison of diagnostic accuracies between fecal S100A12 and fecal calprotectin.

RESULTS

Seven studies comprising 712 children and adolescents (474 non-IBD controls and 238 IBD cases) were included. Fecal S100A12 levels were higher in the IBD group than in the non-IBD group (SMD = 1.88; 95% confidence interval [CI] = 1.19-2.58; p < 0.0001). Fecal S100A12 could diagnose IBD in pediatric patients with a pooled sensitivity of 95% (95% CI = 88%-98%), specificity of 97% (95% CI = 95%-98%), and area under the receiver operating summary characteristics (AUSROC) curve of 0.99 (95% CI = 0.97-0.99). Fecal S100A12 specificity and AUSROC curve values were higher than those of fecal calprotectin (p < 0.05).

CONCLUSION

Fecal S100A12 may serve as an accurate and non-invasive tool for diagnosing pediatric IBD.

Engineered calprotectin-sensing probiotics for IBD surveillance in humans

Inflammatory bowel disease (IBD) is a spectrum of autoimmune diseases affecting the gastrointestinal tract characterized by a relapsing and remitting course of gut mucosal inflammation. Disease flares can be difficult to predict, and the current practice of IBD disease activity surveillance through endoscopy is invasive and requires medical expertise. Recent advancements in synthetic biology raise the possibility that symbiotic microbes can be engineered to selectively detect disease biomarkers used in current clinical practice. Here, we introduce an engineered probiotic capable of detecting the clinical gold standard IBD biomarker, calprotectin, with sensitivity and specificity in IBD patients. Specifically, we identified a bacterial promoter in the probiotic strain Escherichia coli Nissle 1917 (EcN) which exhibits a specific expression increase in the presence of calprotectin. Using murine models of colitis, we show that the reporter signal is activated in vivo during transit of the GI tract following oral delivery. Furthermore, our engineered probiotic can successfully discriminate human patients with active IBD from those in remission and without IBD using patient stool samples, where the intensity of reporter signal quantitatively tracks with clinical laboratory-measured levels of calprotectin. Our pilot study sets the stage for probiotics that can be engineered to detect fecal calprotectin for precise noninvasive disease activity monitoring in IBD patients.

Current and emerging biomarkers for ulcerative colitis

INTRODUCTION

Ulcerative colitis (UC) is a chronic illness requiring lifelong management that could be enhanced by personalizing care using biomarkers.

AREAS COVERED

The main biomarker discovery modalities are reviewed, highlighting recent results across the spectrum of applications, including diagnostics (serum anti-αvβ6 antibodies achieving an area under the curve [AUC] = 0.99; serum oncostatin M AUC = 0.94), disease activity assessment (fecal calprotectin and serum trefoil factor 3: AUC > 0.90), prognostication of the need for treatment escalation (whole blood transcriptomic panels and CLEC5A/CDH2 ratio: AUC > 0.90), prediction of treatment response, and early identification of patients with subclinical disease. The use of established biomarkers is discussed, along with new evidence regarding autoantibodies, proteins, proteomic panels, transcriptomic signatures, deoxyribonucleic acid methylation patterns, and UC-specific glycomic and metabolic disturbances.

EXPERT OPINION

Novel biomarkers will pave the way for optimized UC care. However, validation, simplification, and direct clinical translation of complex models may prove challenging. Currently, few candidates exist to assess key characteristics, such as UC susceptibility, histological disease activity, drug response, and long-term disease behavior. Further research will likely not only reveal new tools to tackle these issues but also contribute to understanding UC pathogenesis mechanisms.

Associations of HIV and iron status with gut microbiota composition, gut inflammation and gut integrity in South African school-age children: a two-way factorial case-control study

BACKGROUND

Human immunodeficiency virus (HIV) and iron deficiency (ID) affect many African children. Both HIV and iron status interact with gut microbiota composition and related biomarkers. The study's aim was to determine the associations of HIV and iron status with gut microbiota composition, gut inflammation and gut integrity in South African school-age children.

METHODS

In this two-way factorial case-control study, 8- to 13-year-old children were enrolled into four groups based on their HIV and iron status: (1) With HIV (HIV+) and ID (n = 43), (2) HIV+ and iron-sufficient nonanaemic (n = 41), (3) without HIV (HIV-) and ID (n = 44) and (4) HIV- and iron-sufficient nonanaemic (n = 38). HIV+ children were virally suppressed (<50 HIV RNA copies/ml) on antiretroviral therapy (ART). Microbial composition of faecal samples (16S rRNA sequencing) and markers of gut inflammation (faecal calprotectin) and gut integrity (plasma intestinal fatty acid-binding protein [I-FABP]) were assessed.

RESULTS

Faecal calprotectin was higher in ID versus iron-sufficient nonanaemic children (p = 0.007). I-FABP did not significantly differ by HIV or iron status. ART-treated HIV (redundancy analysis [RDA] R2  = 0.009, p = 0.029) and age (RDA R2  = 0.013 p = 0.004) explained the variance in the gut microbiota across the four groups. Probabilistic models showed that the relative abundance of the butyrate-producing genera Anaerostipes and Anaerotruncus was lower in ID versus iron-sufficient children. Fusicatenibacter was lower in HIV+ and in ID children versus their respective counterparts. The prevalence of the inflammation-associated genus Megamonas was 42% higher in children with both HIV and ID versus HIV- and iron-sufficient nonanaemic counterparts.

CONCLUSIONS

In our sample of 8- to 13-year-old virally suppressed HIV+ and HIV- children with or without ID, ID was associated with increased gut inflammation and changes in the relative abundance of specific microbiota. Moreover, in HIV+ children, ID had a cumulative effect that further shifted the gut microbiota to an unfavourable composition.

AGA Clinical Practice Guideline on the Role of Biomarkers for the Management of Ulcerative Colitis

BACKGROUND & AIMS

Biomarkers are used frequently for noninvasive monitoring and treatment decision making in the management of patients with ulcerative colitis (UC). This American Gastroenterological Association (AGA) guideline is intended to support practitioners in decisions about the use of biomarkers for the management of UC.

METHODS

A multidisciplinary panel of content experts and guideline methodologists used the Grading of Recommendations Assessment, Development and Evaluation framework to prioritize clinical questions, identify patient-centered outcomes, and conduct an evidence synthesis on the clinical performance of serum C-reactive protein (CRP), fecal calprotectin, and fecal lactoferrin as biomarkers of disease activity in patients with established UC in symptomatic remission or with active symptoms. The guideline panel used the Evidence-to-Decision framework to develop recommendations for the use of biomarkers for monitoring and management of UC and provided implementation considerations for clinical practice.

RESULTS

The guideline panel made 7 conditional recommendations. In patients with UC in symptomatic remission, the panel suggests the use of a biomarker- and symptom-based monitoring strategy over a symptom-based monitoring strategy. For patients in symptomatic remission, the panel suggests using fecal calprotectin <150 μg/g, normal fecal lactoferrin, and/or normal CRP to rule out active inflammation and avoid routine endoscopic assessment of disease. In patients with UC with moderate to severe symptoms, the panel suggests using fecal calprotectin >150 μg/g, elevated fecal lactoferrin, or elevated CRP to inform treatment decisions and avoid routine endoscopic assessment of disease. However, in patients in symptomatic remission but elevated biomarkers, and in patients with moderate to severe symptoms with normal biomarkers, the panel suggests endoscopic assessment of disease to inform treatment decisions. In patients with UC with mild symptoms, the panel suggests endoscopic assessment of disease activity to inform treatment decisions. The panel identified the use of a biomarker-based monitoring strategy over an endoscopy-based monitoring strategy as a knowledge gap. The panel also proposed key implementation considerations for optimal use of biomarkers, and identified areas for future research.

CONCLUSIONS

In patients with UC, noninvasive biomarkers, including fecal calprotectin, fecal lactoferrin, and serum CRP can inform disease monitoring and management.

Intracellular calprotectin (S100A8/A9) facilitates DNA damage responses and promotes apoptosis in head and neck squamous cell carcinoma

OBJECTIVES

In head and neck squamous cell carcinoma (HNSCC), poor prognosis and low survival rates are associated with downregulated calprotectin. Calprotectin (S100A8/A9) inhibits cancer cell migration and invasion and facilitates G2/M cell cycle arrest. We investigated whether S100A8/A9 regulates DNA damage responses (DDR) and apoptosis in HNSCC after chemoradiation.

MATERIALS AND METHODS

Human HNSCC cases in TCGA were analyzed for relationships between S100A8/A9 and expression of apoptosis-related genes. Next, S100A8/A9-expressing and non-expressing carcinoma lines (two different lineages) were exposed to genotoxic agents and assessed for 53BP1 and γH2AX expression and percent of viable/dead cells. Finally, S100A8/A9-wild-type and S100A8/A9null C57BL/6j mice were treated with 4-NQO to induce oral dysplastic and carcinomatous lesions, which were compared for levels of 53BP1.

RESULTS

In S100A8/A9-high HNSCC tumors, apoptosis-related caspase family member genes were upregulated, whereas genes limiting apoptosis were significantly downregulated based on TCGA analyses. After X-irradiation or camptothecin treatment, S100A8/A9-expressing carcinoma cells (i.e., TR146 and KB-S100A8/A9) showed significantly higher 53BP1 and γH2AX expression, DNA fragmentation, proportions of dead cells, and greater sensitivity to cisplatin than wild-type KB or TR146-S100A8/A9-KD cells. Interestingly, KB-S100A8/A9Δ113-114 cells showed similar 53BP1 and γH2AX levels to S100A8/A9-negative KB and KB-EGFP cells. After 4-NQO treatment, 53BP1 expression in oral lesions was significantly greater in calprotectin+/+ than S100A8/A9null mice.

CONCLUSIONS

In HNSCC cells, intracellular calprotectin is strongly suggested to potentiate DDR and promote apoptosis in response to genotoxic agents. Hence, patients with S100A8/A9-high HNSCC may encounter more favorable outcomes because more tumor cells enter apoptosis with increased sensitivity to chemoradiation therapy.

Patient-Reported Outcomes Correlate With Microbial Community Composition Independent of Mucosal Inflammation in Pediatric Inflammatory Bowel Disease

BACKGROUND

Inflammatory bowel diseases (IBDs) involve an aberrant host response to intestinal microbiota causing mucosal inflammation and gastrointestinal symptoms. Patient-reported outcomes (PROs) are increasingly important in clinical care and research. Our aim was to examine associations between PROs and fecal microbiota in patients 0 to 22 years of age with IBD.

METHODS

A longitudinal, prospective, single-center study tested for associations between microbial community composition via shotgun metagenomics and PROs including stool frequency and rectal bleeding in ulcerative colitis (UC) and abdominal pain and stool frequency in Crohn's disease (CD). Mucosal inflammation was assessed with fecal calprotectin. A negative binomial mixed-effects model including clinical characteristics and fecal calprotectin tested for differentially abundant species and metabolic pathways by PROs.

RESULTS

In 70 CD patients with 244 stool samples, abdominal pain correlated with increased relative abundance of Haemophilus and reduced Clostridium spp. There were no differences relative to calprotectin level. In 23 UC patients with 76 samples, both rectal bleeding and increased stool frequency correlated with increased Klebsiella and reduced Bacteroides spp. Conversely, UC patients with lower calprotectin had reduced Klebsiella. Both UC and CD patients with active symptoms exhibited less longitudinal microbial community stability. No differences in metabolic pathways were observed in CD. Increased sulfoglycolysis and ornithine biosynthesis correlated with symptomatic UC.

CONCLUSIONS

Microbial community composition correlated with PROs in both CD and UC. Metabolic pathways differed relative to PROs in UC, but not CD. Data suggest that microbiota may contribute to patient symptoms in IBD, in addition to effects of mucosal inflammation.

Effects of ivacaftor on systemic inflammation and the plasma proteome in people with CF and G551D

BACKGROUND

Ivacaftor is a cystic fibrosis transmembrane conductance regulator (CFTR) potentiator for people with CF and the G551D mutation. We aimed to investigate the biology of CFTR modulation and systemic effects of CFTR restoration by examining changes in circulating measurements of inflammation and growth and novel proteins with ivacaftor treatment.

METHODS

Blood samples from 64 CF subjects with G551D-CFTR were analyzed for inflammatory and growth-related proteins at baseline, 1 and 6 months after ivacaftor initiation. In 30 subjects, plasma was assayed for 1,322 proteins using the SomaScan proteomic platform at baseline and 6 months post-ivacaftor. Correlations with clinical outcomes were assessed.

MEASUREMENTS AND MAIN RESULTS

Significant reductions in high mobility group box-1 protein (HMGB-1), calprotectin, serum amyloid A, and granulocyte colony-stimulating factor (G-CSF), and an increase in insulin-like growth factor (IGF-1) occurred 1 month after ivacaftor. This treatment effect was sustained at 6 months for HMGB-1 and calprotectin. Correcting for multiple comparisons in the proteomic analysis, 9 proteins (albumin, afamin, leptin, trypsin, pancreatic stone protein [PSP], pituitary adenylate cyclase-activating polypeptide-38, repulsive guidance molecule A [RGMA], calreticulin, GTPase KRas) changed significantly with ivacaftor. Proteins changing with treatment are involved in lipid digestion and transport and extracellular matrix organization biological processes. Reductions in calprotectin and G-CSF and increases in calreticulin, and RGMA correlated with improved lung function, while increasing IGF-1, leptin and afamin and decreasing PSP correlated with increased weight.

CONCLUSIONS

Ivacaftor led to changes in inflammatory, lipid digestion, and extracellular matrix proteins, lending insights into the extrapulmonary effects of CFTR modulation.

Preterm Infant Fecal Microbiota and Metabolite Profiles Are Modulated in a Probiotic Specific Manner

OBJECTIVES

To compare the impact of two probiotic supplements on fecal microbiota and metabolites, as well as on gut inflammation in human milk-fed preterm infants.

METHODS

In this single-center observational cohort study, we assessed the effects of Bifidobacterium longum subsp. infantis or Lactobacillus reuteri supplementation on the infant gut microbiota by 16S rRNA gene sequencing and fecal metabolome by 1 H nuclear magnetic resonance spectroscopy. Fecal calprotectin was measured as a marker of enteric inflammation. Aliquots of human or donor milk provided to each infant were also assessed to determine human milk oligosaccharide (HMO) content.

RESULTS

As expected, each probiotic treatment was associated with increased proportions of the respective bacterial taxon. Fecal HMOs were significantly higher in L. reuteri fed babies despite similar HMO content in the milk consumed. Fecal metabolites associated with bifidobacteria fermentation products were significantly increased in B. infantis supplemented infants. Fecal calprotectin was lower in infants receiving B. infantis relative to L. reuteri ( P < 0.01, Wilcoxon rank-sum test) and was negatively associated with the microbial metabolite indole-3-lactate (ILA).

CONCLUSIONS

This study demonstrates that supplementing an HMO-catabolizing Bifidobacterium probiotic results in increased microbial metabolism of milk oligosaccharides and reduced intestinal inflammation relative to a noncatabolizing Lactobacillus probiotic in human milk-fed preterm infants. In this context, Bifidobacterium may provide greater benefit in human milk-fed infants via activation of the microbiota-metabolite-immune axis.

Prevalence and factors associated with vitamin C deficiency in inflammatory bowel disease

BACKGROUND

Patients with inflammatory bowel disease (IBD) are prone to several nutritional deficiencies. However, data are lacking on vitamin C deficiency in Crohn’s disease (CD) and ulcerative colitis (UC) patients, as well as the impact of clinical, biomarker and endoscopic disease severity on the development of vitamin C deficiency.

AIM

To determine proportions and factors associated with vitamin C deficiency in CD and UC patients.

METHODS

In this retrospective study, we obtained clinical, laboratory and endoscopic data from CD and UC patients presenting to the IBD clinic at a single tertiary care center from 2014 to 2019. All patients had an available plasma vitamin C level. Of 353 subjects who met initial search criteria using a cohort discovery tool, 301 ultimately met criteria for inclusion in the study. The primary aim described vitamin C deficiency (≤ 11.4 μmol/L) rates in IBD. Secondary analyses compared proportions with deficiency between active and inactive IBD. Multivariate logistic regression analysis evaluated factors associated with deficiency.

RESULTS

Of 301 IBD patients, 21.6% had deficiency, including 24.4% of CD patients and 16.0% of UC patients. Patients with elevated C-reactive protein (CRP) (39.1% vs 16.9%, P < 0.001) and fecal calprotectin (50.0% vs 20.0%, P = 0.009) had significantly higher proportions of deficiency compared to those without. Penetrating disease (P = 0.03), obesity (P = 0.02) and current biologic use (P = 0.006) were also associated with deficiency on univariate analysis. On multivariate analysis, the objective inflammatory marker utilized for analysis (elevated CRP) was the only factor associated with deficiency (odds ratio = 3.1, 95% confidence interval: 1.5-6.6, P = 0.003). There was no difference in the presence of clinical symptoms of scurvy in those with vitamin C deficiency and those without.

CONCLUSION

Vitamin C deficiency was common in IBD. Patients with elevated inflammatory markers and penetrating disease had higher rates of vitamin C deficiency.

Mn uptake system affects the virulence of Streptococcus suis by mediating oxidative stress

Manganese (Mn) is an important micronutrient that is not readily available to pathogens during infection. Hosts resist the invasion of pathogens through nutritional immunity and oxidative stress. To overcome this nutrient restriction, bacteria utilize high affinity transporters to compete with nutrient-binding proteins (e.g., calprotectin). Little is known about the role of Mn in the pathophysiology of Streptococcus suis. Here, we revealed that the tolerance of S. suis to calprotectin and oxidative stress was associated with Mn. Inactivation of Mn uptake system, TroABCD, in S. suis decreased the tolerance to calprotectin and oxidative stress. Furthermore, Mn uptake system mutant strains reduced capacity for bacterial cellular survival, and attenuated virulence in a mouse model. To explore the regulatory mechanism, we determined the transcriptional start site of troABCD using capping rapid amplification of cDNA ends. Furthermore, we revealed that TroR was a transcriptional regulatory repressor of troABCD. In the absence of troR, transcription levels of troA, troB, troC, and troD were not inhibited by low or high Mn levels, and intracellular Mn contents of mutant strains were higher than that of the wild-type strain. Finally, we used electrophoretic mobility shift assay to demonstrate that TroR bound the promoter region of troABCD. Collectively, this study revealed that Mn acquisition was essential for pathogenesis of S. suis and Mn uptake systems should be targets for the development of new antimicrobials.

Dynamic regulation of Zn(II) sequestration by calgranulin C

Calgranulin C performs antimicrobial activity in the human immune response by sequestering Zn(II). This biological function is afforded with the aid of two structurally distinct Ca(II)-binding EF hand motifs, wherein one of which bears an unusual amino acid sequence. Here, we utilize solution state NMR relaxation measurements to investigate the mechanism of Ca(II)-modulated enhancement of Zn(II) sequestration by calgranulin C. Using C13 /N15 CPMG dispersion experiments we have measured pH-dependent major and minor state populations exchanging on micro-to-millisecond timescale. This conformational exchange takes place exclusively in the Ca(II)-bound state and can be mapped to residues located in the EF-I loop and the linker between the tandem EF hands. Molecular dynamics (MD) simulations spanning nano-to-microsecond timescale offer insights into the role of pH-dependent electrostatic interactions in EF-hand dynamics. Our results suggest a pH-regulated dynamic equilibrium of conformations that explore a range of "closed" and partially "open" sidechain configurations within the Zn(II) binding site. We propose a novel mechanism by which Ca(II) binding to a non-canonical EF loop regulates its flexibility and tunes the antimicrobial activity of calgranulin C.

The Potential Use of Saliva as a Biofluid for Systemic Inflammatory Response Monitoring in Children with Pneumonia

OBJECTIVE

To investigate the levels of C-reactive protein, procalcitonin, calprotectin, interleukin 1 beta (IL-1β), IL-6, and tumor necrosis factor-alpha (TNF-α) in both saliva and serum in children with community-acquired pneumonia and to compare the saliva response with the systemic response.

METHODS

Forty hospitalized children with community-acquired pneumonia aged between 1 mo and 15 y; and 40 healthy controls were included. Both serum and saliva samples were collected on admission and at the time of discharge.

RESULTS

Calculated differences between values for each serum and salivary parameter on admission and before discharge named delta (Δ) values were used for correlation analysis. Salivary Δ values of each parameter were moderately/strongly correlated with their corresponding serum Δ levels [IL-1β ÷ (r = 0.554, p < 0.001); IL-6 ÷ (r = 0.484, p = 0.002); PCT ÷ (r = 0.737, p < 0.001); TNF-α ÷ (r = 0.587, p < 0.001); CRP ÷ (r = 0.703, p < 0.001); and calprotectin ÷ (r = 0.774, p < 0.001)].

CONCLUSIONS

This study will evaluate the reflection of systemic changes in saliva and the efficacy of saliva in pediatric patients with pneumonia. Results will highlight saliva potential use as a biofluid for systemic monitoring in this patient group.

Lycopodium Mitigates Oxidative Stress and Inflammation in the Colonic Mucosa of Acetic Acid-Induced Colitis in Rats

Inflammatory bowel diseases (IBDs) such as ulcerative colitis (UC) and Crohn’s disease (CD) are diseases of the gastrointestinal system involving genetic and environmental factors attributed to oxidative stress and inflammation. Targeting oxidative stress and inflammation by novel dietary compounds of natural origin convincingly appears to be one of the important therapeutic strategies to keep the disease in remission. As there is no permanent cure for IBD except for chronic long-term treatment or surgery, it is therefore imperative to investigate plant-based agents that are receiving attention for their therapeutic benefits to overcome the debilitating clinical conditions of IBD. Lycopodium (LYCO), a plant of tropical and subtropical origin and known by numerous names such as ground pine, club moss, or devil’s claw, has been popularly used for centuries in traditional medicine including Chinese and Indian medicines. In the present study, the effect of LYCO has been investigated in an acetic acid (AA)-induced colitis model in Wistar rats. LYCO was orally administered at the dose of 50 mg/kg/day either 3 days before or 30 min after the induction of IBD and continued for 7 days by intrarectal administration of AA. The changes in body weight and macroscopic and microscopic analysis of the colon of rats of different experimental groups were observed on days 0, 2, 4, and 7. The levels of myeloperoxidase (MPO), reduced glutathione (GSH), and malondialdehyde (MDA) were measured. AA caused a significant reduction in body weight and increased macroscopic and microscopic ulcer scores along with a significant decline in antioxidant enzymes, superoxide dismutase (SOD), and catalase and antioxidant substrate, glutathione (GSH). There was a concomitant increased formation of malondialdehyde (MDA), a marker of lipid peroxidation, and raised myeloperoxidase (MPO) activity, a marker of neutrophil activation. Treatment with LYCO significantly improved IBD-induced reduction in body weight, improved histology, inhibited MDA formation, and restored antioxidants along with reduced MPO activity. AA also caused the release of proinflammatory cytokines such as interleukin-1β (IL-1β) and interleukin-23 (IL-23). Furthermore, AA also increased the levels of calprotectin, a protein released by neutrophils under inflammatory conditions of the gastrointestinal tract. LYCO treatment significantly reduced the release of calprotectin and proinflammatory cytokines. The results demonstrate that LYCO treatment has the potential to improve disease activity by inhibiting oxidative stress, lipid peroxidation, and inflammation along with histological preservation of colonic tissues.

Involvement of Oxidative Stress in Protective Cardiac Functions of Calprotectin

Calprotectin (CLP) belonging to the S-100 protein family is a heterodimeric complex (S100A8/S100A9) formed by two binding proteins. Upon cell activation, CLP stored in neutrophils is released extracellularly in response to inflammatory stimuli and acts as damage-associated molecular patterns (DAMPs). S100A8 and S100A9 possess both anti-inflammatory and anti-bacterial properties. The complex is a ligand of the toll-like receptor 4 (TLR4) and receptor for advanced glycation end (RAGE). At sites of infection and inflammation, CLP is a target for oxidation due to its co-localization with neutrophil-derived oxidants. In the heart, oxidative stress (OS) responses and S100 proteins are closely related and intimately linked through pathophysiological processes. Our review summarizes the roles of S100A8, S100A9 and CLP in the inflammation in relationship with vascular OS, and we examine the importance of CLP for the mechanisms driving in the protection of myocardium. Recent evidence interpreting CLP as a critical modulator during the inflammatory response has identified this alarmin as an interesting drug target.

Learning Longitudinal Patterns and Subtypes of Pediatric Crohn Disease Treated With Infliximab via Trajectory Cluster Analysis

BACKGROUND

The objective of this study is to identify subgroups of pediatric Crohn disease (CD) who had differential responses to the infliximab treatment through trajectory cluster analysis of disease activity using data from electronic health records.

METHODS

We conducted a retrospective study of 295 pediatric patients with CD who had been treated with infliximab for a minimum of one year at the Center for Inflammatory Bowel Disease at The Children's Hospital of Philadelphia between January 2010 and December 2017. The evolution of disease was described, and subgroups of patients were identified using trajectory analysis of longitudinal data of C-reactive protein (CRP). We compared patient characteristics, biomarker for disease activity, and long-term surgical outcomes across subgroups. Cox regression models were used to evaluate the added value of the subgroup classification to baseline phenotype and location in prediction of long-term surgical outcomes.

RESULTS

We identified three subgroups of patients with differential relapse-and-remission profiles (n = 33, 65 and 197 from subgroup 1 to 3), which represented patients with a higher risk of infliximab non-response, with infliximab response but with occasional disease flares, and patients with long-term response. Patients with the best treatment response had a significantly lower frequency of complicated disease phenotypes (P = 0.01), including perianal involvement (P = 0.05), lower baseline CRP (P < 0.01) and calprotectin (P = 0.01), and lowest risk of IBD-related gastrointestinal surgery within 10 years of starting treatment (P < 0.01).

CONCLUSIONS

Readily available longitudinal data from electronic health records can be leveraged to provide deeper characterization of treatment response in pediatric CD.

[Fecal calprotectin as a diagnostic marker of inflammatory bowel disease]

Inflammatory bowel disease (IBD) is a group of diseases characterized by chronic and recurrent inflammation of the gastrointestinal tract. The incidence of IBD has increased significantly in past decades. The aim of this study is to review the literature on the possibility of using fecal calprotectin in the diagnosis of inflammatory bowel disease, the assessment of the severity of the disease, the prediction of a relapse and the monitoring of remission. The literature review was conducted using the PubMed and Google Scholar databases. Most of the publications included in the study are from 2013 or later. Laboratory, imaging, endoscopic and histopathological tests are used in the diagnosis of IBD. In order to confirm the diagnosis, an endoscopic examination with the collection and evaluation of histopathological specimens is required. Laboratory tests useful in the diagnosis of non-specific inflammations include non-specific tests such as the white blood cells count, ESR and CRP. Faecal calprotectin is a protein complex produced by neutrophils in the inflamed gut. The studies included in this review have shown the presence of increased levels of fecal calprotectin in patients with relapses in the course of inflammatory bowel disease. Accordingly, determination of this marker may be useful in the diagnosis of chronic abdominal pain and as screening prior to colonoscopy.

Formation of Calprotectin-Derived Peptides in the Airways of Children with Cystic Fibrosis

Calprotectin is released by activated neutrophils along with myeloperoxidase (MPO) and proteases. It plays numerous roles in inflammation and infection, and is used as an inflammatory biomarker. However, calprotectin is readily oxidized by MPO-derived hypohalous acids to form covalent dimers of its S100A8 and S100A9 subunits. The dimers are susceptible to degradation by proteases. We show that detection of human calprotectin by ELISA declines markedly because of its oxidation by hypochlorous acid and subsequent degradation. Also, proteolysis liberates specific peptides from oxidized calprotectin that is present at inflammatory sites. We identified six calprotectin-derived peptides by mass spectrometry and detected them in the bronchoalveolar lavage fluid of children with cystic fibrosis (CF). We assessed the peptides as biomarkers of neutrophilic inflammation and infection. The content of the calprotectin peptide ILVI was related to calprotectin (r = 0.72, p = 0.01, n = 10). Four of the peptides were correlated with the concentration of MPO (r > 0.7, p ≤ 0.01, n = 21), while three were higher (p < 0.05) in neutrophil elastase-positive (n = 14) than -negative samples (n = 7). Also, five of the peptides were higher (p < 0.05) in the bronchoalveolar lavage fluid from children with CF with infections (n = 21) than from non-CF children without infections (n = 6). The specific peptides liberated from calprotectin will signal uncontrolled activity of proteases and MPO during inflammation. They may prove useful in tracking inflammation in respiratory diseases dominated by neutrophils, including coronavirus disease 2019.

Zinc sequestration by human calprotectin facilitates manganese binding to the bacterial solute-binding proteins PsaA and MntC

Zinc is an essential transition metal nutrient for bacterial survival and growth but may become toxic when present at elevated levels. The Gram-positive bacterial pathogen Streptococcus pneumoniae is sensitive to zinc poisoning, which results in growth inhibition and lower resistance to oxidative stress. Streptococcus pneumoniae has a relatively high manganese requirement, and zinc toxicity in this pathogen has been attributed to the coordination of Zn(II) at the Mn(II) site of the solute-binding protein (SBP) PsaA, which prevents Mn(II) uptake by the PsaABC transport system. In this work, we investigate the Zn(II)-binding properties of pneumococcal PsaA and staphylococcal MntC, a related SBP expressed by another Gram-positive bacterial pathogen, Staphylococcus aureus, which contributes to Mn(II) uptake. X-ray absorption spectroscopic studies demonstrate that both SBPs harbor Zn(II) sites best described as five-coordinate, and metal-binding studies in solution show that both SBPs bind Zn(II) reversibly with sub-nanomolar affinities. Moreover, both SBPs exhibit a strong thermodynamic preference for Zn(II) ions, which readily displace bound Mn(II) ions from these proteins. We also evaluate the Zn(II) competition between these SBPs and the human S100 protein calprotectin (CP, S100A8/S100A9 oligomer), an abundant host-defense protein that is involved in the metal-withholding innate immune response. CP can sequester Zn(II) from PsaA and MntC, which facilitates Mn(II) binding to the SBPs. These results demonstrate that CP can inhibit Zn(II) poisoning of the SBPs and provide molecular insight into how S100 proteins may inadvertently benefit bacterial pathogens rather than the host.

Low Levels of Fecal Calprotectin 3 Months After Surgery Predict Subsequent Endoscopic Postoperative Remission in Crohn's Disease

BACKGROUND/AIMS

In Crohn's disease (CD) few data are available on the usefulness of monitoring fecal calprotectin (FC) in the early postoperative setting. We assessed prospectively the accuracy of FC measured 3 months after surgery to predict the risk of endoscopic postoperative recurrence (POR) within 1 year after resection.

METHODS

In 55 consecutive CD patients who had undergone ileocolonic resection samples were collected 3 months after surgery for measuring serum CRP and FC. Endoscopic POR was assessed by ileocolonoscopy within 6-12 months (median 7 months). Receiver operating characteristic (ROC) curves were generated to assess accuracy of the markers, to determine the best threshold and to calculate sensitivity, specificity, positive and negative predictive values.

RESULTS

In contrast with median CRP levels, median FC concentrations measured 3 months after surgery were significantly higher in patients who later experienced endoscopic POR (Rutgeerts ≥ i2) compared with those who stayed in endoscopic remission within the following 6-12 months (205 μg/g IQR [106-721] vs. 103 μg/g IQR [60-219], p = 0.008). Area under the ROC curve for FC was 0.71. The best cutoff value of FC to identify patients in subsequent endoscopic remission 3 months after surgery was 65 μg/g (96% sensitivity, 31% specificity, 50% positive and 91% negative predictive values). In multivariate analysis, FC < 65 µg/g at 3 months was the only factor associated with subsequent endoscopic remission.

CONCLUSION

FC measured 3 months after surgery below 65 μg/g is an accurate marker to identify CD patients who will later stay in endoscopic remission within 1 year after resection.

Bacterial Responses to Iron Withholding by Calprotectin

Iron (Fe) plays important roles in both essential cellular processes and virulence pathways for many bacteria. Consequently, Fe withholding by the human innate immune system is an effective form of defense against bacterial infection. In this Perspective, we review recent studies that have established a foundation for our understanding of the impact of the metal-sequestering host defense protein calprotectin (CP) on bacterial Fe homeostasis. We also discuss two recently uncovered strategies for bacterial adaptation to Fe withholding by CP. Together, these studies provide insight into how Fe sequestration by CP affects bacterial pathogens that include Pseudomonas aeruginosa, Acinetobacter baumannii, and Staphylococcus aureus. Overall, recent studies suggest that Fe withholding by CP may have implications for bacterial survival and virulence in the host, and further explorations that directly address this possibility present an important area for discovery.

Post-Induction High Adalimumab Drug Levels Predict Biological Remission at Week 24 in Patients With Crohn's Disease

INTRODUCTION

We investigated whether early adalimumab drug levels (ADL) at week 4 predicted biological remission at week 24.

METHODS

In a prospective study, we assessed clinical and biological remission at weeks 0, 4, 12, and 24 after induction of adalimumab in 33 patients with Crohn's disease. Disease activity was determined by the Harvey-Bradshaw Index, ileocolonoscopy reports, cross-sectional imaging, C-reactive protein (CRP), and fecal calprotectin (FC) levels. Clinical remission was defined as Harvey-Bradshaw Index <5. Biological remission was defined as a combination of FC < 200 μg/g and CRP <5 μg/mL. ADL trough levels were tested using a liquid phase, mobility shift assay.

RESULTS

At 24 weeks, 18/33 (55%) of the patients were with biological remission. Ten (30%) patients required dose escalation or withdrawal from adalimumab by week 24 because of lack of response and exhibited significantly higher FC (P = 0.003) and CRP (P = 0.002). ADL levels at week 4 (19.8 μg/mL vs 10.2 μg/mL, P = 0.001) were significantly higher in patients with biological remission vs nonresponders at week 24. ADL levels at week 4 were a good predictor of biological remission at week 24, with area under the curve 0.86, 95% confidence interval (1.1; 1.67) and for combined biological and clinical remission, with area under the curve 0.8. The best ADL cutoff at week 4 that predicted biological remission at week 24 was 13.9 μg/mL (sensitivity 94.4% and specificity 73.3%).

DISCUSSION

In individuals with Crohn's disease, higher adalimumab drug levels at week 4 (>13.9 μg/mL) were significantly associated with biological remission at week 24.

Calprotectin: from biomarker to biological function

The incidence of inflammatory bowel diseases (IBD) emerged with Westernisation of dietary habits worldwide. Crohn's disease and ulcerative colitis are chronic debilitating conditions that afflict individuals with substantial morbidity and challenge healthcare systems across the globe. Since identification and characterisation of calprotectin (CP) in the 1980s, faecal CP emerged as significantly validated, non-invasive biomarker that allows evaluation of gut inflammation. Faecal CP discriminates between inflammatory and non-inflammatory diseases of the gut and portraits the disease course of human IBD. Recent studies revealed insights into biological functions of the CP subunits S100A8 and S100A9 during orchestration of an inflammatory response at mucosal surfaces across organ systems. In this review, we summarise longitudinal evidence for the evolution of CP from biomarker to rheostat of mucosal inflammation and suggest an algorithm for the interpretation of faecal CP in daily clinical practice. We propose that mechanistic insights into the biological function of CP in the gut and beyond may facilitate interpretation of current assays and guide patient-tailored medical therapy in IBD, a concept warranting controlled clinical trials.

Faecal biomarkers in type 1 diabetes with and without diabetic nephropathy

Gastrointestinal dysbiosis is common among persons with type 1 diabetes (T1D), but its potential impact on diabetic nephropathy (DN) remains obscure. We examined whether faecal biomarkers, previously associated with low-grade gastrointestinal inflammation, differ between healthy controls and T1D subjects with and without DN. Faecal samples were analyzed for levels of calprotectin, intestinal alkaline phosphatase (IAP), short-chain fatty acids (SCFA) and immunoglobulins in subjects with T1D (n = 159) and healthy controls (NDC; n = 50). The subjects with T1D were stratified based on albuminuria: normoalbuminuria (< 30 mg/g; n = 49), microalbuminuria (30-299 mg/g; n = 50) and macroalbuminuria (≥ 300 mg/g; n = 60). aecal calprotectin, IAP and immunoglobulin levels did not differ between the T1D albuminuria groups. However, when subjects were stratified based on faecal calprotectin cut-off level (50 µg/g), macroalbuminuric T1D subjects exceeded the threshold more frequently than NDC (p = 0.02). Concentrations of faecal propionate and butyrate were lower in T1D subjects compared with NDC (p = 0.04 and p = 0.03, respectively). Among T1D subjects, levels of branched SCFA (BCFA) correlated positively with current albuminuria level (isobutyrate, p = 0.03; isovalerate, p = 0.005). In our study cohort, fatty acid metabolism seemed to be altered among T1D subjects and those with albuminuria compared to NDC. This may reflect gastrointestinal imbalances associated with T1D and renal complications.

Molecular and Histological Profiling Reveals an Innate-Shaped Immune Microenvironment in Solitary Juvenile Polyps

INTRODUCTION

Solitary juvenile polyps (JP) are characterized by a benign disease course with low recurrence rate but present with signs of intestinal inflammation. To better understand the underlying pathogenesis, we performed histological and molecular evaluation targeting distinct immune mechanisms.

METHODS

Pediatric patients with JP (n = 12), with treatment-naïve inflammatory bowel disease (IBD; [n = 41]) as inflammatory control, and non-IBD controls (n = 14) were investigated. For a comparative analysis of infiltrating immune cells, a next-generation tissue microarray of biopsies was assembled, immunostained, and scored. Targeted transcriptional profiling was performed using a customized immunology panel.

RESULTS

In JP, a predominant accumulation of neutrophils and eosinophils was observed. RNA expression profiles revealed increased levels of CXCL8, CXCL5, and CCL11 transcripts in JP, indicating an enhanced recruitment of neutrophils and eosinophils. Moreover, messenger RNA levels of the proinflammatory cytokine IL1b and the inflammation-amplifying receptor TREM1 were higher in JP, whereas we could not find signs of a functionally polarized Tcell response in JP when compared with IBD.

DISCUSSION

Patients with JP and patients with treatment-naïve IBD have distinct cell infiltrates during active disease. The ample presence of eosinophils in JP supports neutrophil accumulation, which is responsible for the elevated release of calprotectin. Intriguingly, however, we were not able to identify a functionally polarized T-cell response in JP, which indicates that during the acute onset of inflammation in JP, a potent adaptive immune memory is not established. This may explain the low reoccurrence rate of JP.

Low curcumin concentration enhances the anticancer effect of 5-fluorouracil against colorectal cancer

BACKGROUND

Colon cancer treatments include surgery, radiotherapy, and chemotherapy. Chemotherapy using 5-fluorouracil (5-FU) has been widely applied to treat colorectal cancer (CRC). However, it is important to explore the use of chemotherapy drugs in combination with other agents to decrease severe adverse effects.

PURPOSE

This study aimed to investigate the effects of curcumin in combination with 5-FU on the proliferation, migration, and apoptosis of CRC SW620 cell line both in vitro and in vivo.

METHODS

Flow cytometry was used to study the effect of curcumin on chemotherapy-induced apoptosis in CRC cells. The mechanism of curcumin's enhanced antitumor effect in vivo was investigated using gene knockdown, TUNEL, western blot, qRT-PCR and immunohistochemistry.

RESULTS

The results showed a synergistic effect of the two compounds on CRC cells. Considerable reduction in the proliferation and migration of SW620 cells was observed in the combination treatment group. Significantly increased apoptosis rate extended the survival of immunodeficient mice in the combination group as compared to that of the 5-FU group (p < 0.05). The results showed that curcumin significantly inhibited pERK signaling and downregulated L1 expression in SW620 cells.

CONCLUSIONS

We conclude that curcumin promotes chemosensitivity of CRC cells to 5-FU by downregulating L1 expression. Our findings provide experimental evidence for the synergism between curcumin and 5-FU, which can be utilized in clinical applications for reducing the toxicity and adverse effects of 5-FU.

Potential intestinal infection and faecal-oral transmission of SARS-CoV-2

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread to more than 200 countries and regions globally. SARS-CoV-2 is thought to spread mainly through respiratory droplets and close contact. However, reports have shown that a notable proportion of patients with coronavirus disease 2019 (COVID-19) develop gastrointestinal symptoms and nearly half of patients confirmed to have COVID-19 have shown detectable SARS-CoV-2 RNA in their faecal samples. Moreover, SARS-CoV-2 infection reportedly alters intestinal microbiota, which correlated with the expression of inflammatory factors. Furthermore, multiple in vitro and in vivo animal studies have provided direct evidence of intestinal infection by SARS-CoV-2. These lines of evidence highlight the nature of SARS-CoV-2 gastrointestinal infection and its potential faecal-oral transmission. Here, we summarize the current findings on the gastrointestinal manifestations of COVID-19 and its possible mechanisms. We also discuss how SARS-CoV-2 gastrointestinal infection might occur and the current evidence and future studies needed to establish the occurrence of faecal-oral transmission.

Fecal Dipeptidyl Peptidase-4: An Emergent Biomarker in Inflammatory Bowel Disease

INTRODUCTION

Dipeptidyl peptidase-4 (DPP-4) is a membrane-bound glycoprotein that acts as a receptor but also exists in a soluble form. It has been recognized as a mediator of inflammation and considered a biomarker in inflammatory bowel disease (IBD).

METHODS

We evaluated a prospectively recruited cohort, consisting of 101 patients with IBD, using validated clinical indexes; 22 patients with ulcerative colitis (UC) underwent endoscopic evaluation. Fecal DPP-4 (fDPP-4) levels were analyzed and correlated with clinical scores, Mayo endoscopic score (in UC patients), serum DPP-4, C-reactive protein, and fecal calprotectin. Immunohistochemical staining for DPP-4 in intestinal biopsies was also performed.

RESULTS

When compared with remitters, median fDPP-4 levels were higher in patients with ileal Crohn's disease (CD) (7,584 [1,464-7,816] vs 2,104 [630-2,676] ng/mL, P = 0.015) and lower in patients with UC exhibiting clinical activity (1,213 [559-1,682] vs 7,814 [2,555-7,985] ng/mL, P < 0.001). Patients with UC presenting endoscopic activity also had lower levels than remitters (939 [559-1,420] vs 7,544 [4,531-7,940] ng/mL, P = 0.006). Fecal DPP-4 discriminated clinical activity from remission with areas under the curve of 0.76 (95% confidence interval [CI] 0.58-0.94, P = 0.015) and 0.80 (95% CI 0.68-0.93, P < 0.001) in CD and UC, respectively; it allowed to differentiate endoscopic activity in patients with UC, with areas under the curve of 0.84 (95% CI 0.63-1.00, P = 0.009). Immunohistochemical analysis revealed higher DPP-4 apical expression in UC remitters, but no statistically significant differences were revealed between patients with ileal CD.

DISCUSSION

Our results suggest that fDPP-4 can be used as a biomarker of IBD activity, particularly in UC. The expression profiles in intestinal tissue might represent a functional compartmentalization of DPP-4 expression.

Calprotectin in Lung Diseases

Calprotectin (CLP) is a heterodimer formed by two S-100 calcium-binding cytosolic proteins, S100A8 and S100A9. It is a multifunctional protein expressed mainly by neutrophils and released extracellularly by activated or damaged cells mediating a broad range of physiological and pathological responses. It has been more than 20 years since the implication of S100A8/A9 in the inflammatory process was shown; however, the evaluation of its role in the pathogenesis of respiratory diseases or its usefulness as a biomarker for the appropriate diagnosis and prognosis of lung diseases have only gained attention in recent years. This review aimed to provide current knowledge regarding the potential role of CLP in the pathophysiology of lung diseases and describe how this knowledge is, up until now, translated into daily clinical practice. CLP is involved in numerous cellular processes in lung health and disease. In addition to its anti-microbial functions, CLP also serves as a molecule with pro- and anti-tumor properties related to cell survival and growth, angiogenesis, DNA damage response, and the remodeling of the extracellular matrix. The findings of this review potentially introduce CLP in daily clinical practice within the spectrum of respiratory diseases.

Fecal calprotectin as a noninvasive test to predict deep remission in patients with ulcerative colitis

Mucosal healing (MH) has become a major target in the management of ulcerative colitis (UC). Because repeat endoscopy is expensive and invasive, we aimed to evaluate fecal calprotectin (FC) as an alternative marker to predict MH in UC.Eighty patients with UC in clinical remission were consecutively included in a prospective observational study. FC was measured using a quantitative enzyme-linked immunosorbent assay. The colonic mucosa was assessed for endoscopic and histological measures of inflammatory status. Endoscopic and histological remission were defined according to the Mayo endoscopic subscore (MES) and Geboes score (GS), respectively. Deep remission was defined as a combination of the MES and GS. FC performance and cutoff values for identifying MH and deep remission were determined using contingency tables and receiver operator characteristic (ROC) and area under the curve (AUC) analysis.The median FC concentration in patients who met the criteria for deep remission (MES ≤1 and GS < 3.1) was 65.5 μg/g, while that in patients with disease activity was 389.6 μg/g (P = .025). A FC cutoff value of 100 μg/g, determined by the ROC analysis, resulted in sensitivity and specificity of 91.7% and 57.1%, respectively, for histological remission, and 82.4% and 60.9%, respectively, for deep mucosal remission. Positive correlations were detected between FC concentrations with the histologic (CC: 0.435; P < .001) and the combined endoscopic and histologic (CC: 0.413; P < .001) scores.FC can be used confidently as a noninvasive biomarker to predict deep remission in patients with UC in clinical remission when concentrations are below 100 μg/g.

Long-term docosahexaenoic acid (DHA) supplementation in cystic fibrosis patients: a randomized, multi-center, double-blind, placebo-controlled trial

BACKGROUND

Cystic fibrosis (CF) patients have an alteration in fatty acid (FA) metabolism, associated with increased omega-6 and low omega-3 FA. Previous studies on supplementation with omega-3 FA in CF had contradictory results, and to date there is no evidence to recommend routine use of omega-3 supplements in CF patients. We hypothesized that long-term supplementation with docosahexaenoic acid (DHA) will have beneficial effects in these patients, by reducing pulmonary, systemic and intestinal inflammation.

METHODS

This was a randomized, double-blind, parallel, placebo-controlled trial. CF patients (age >2 months) were randomized to receive a seaweed DHA oil solution (50 mg/Kg/day) or matching placebo for 48 weeks. Primary outcomes were pulmonary (interleukin [IL]-8), systemic (IL-8) and intestinal (calprotectin) inflammatory biomarkers. Secondary outcomes included other pulmonary (IL-1β, IL-6, neutrophil elastase, lactate and calprotectin) and systemic (serum-IL-1β, IL-6) inflammatory biomarkers, as well as clinical outcomes (FEV₁, pulmonary exacerbations, antibiotic use, nutritional status and quality of life).

RESULTS

Ninety six CF patients, 44 female, age 14.6±11.9 years (48 DHA and 48 placebo) were included. At trial completion, there were no differences in all primary outcomes [serum-IL-8 (p=0.909), respiratory-IL-8 (p=0.384) or fecal calprotectin (p=0.948)], all secondary inflammatory biomarkers, or in any of the clinical outcomes evaluated. There were few adverse events, with similar incidence in both study groups.

CONCLUSION

In this study, long-term DHA supplementation in CF patients was safe, but did not offer any benefit on inflammatory biomarkers, or in clinical outcomes compared with placebo. (NCT01783613).

Serum Calprotectin and Chemerin Concentrations as Markers of Low-Grade Inflammation in Prepubertal Children with Obesity

In adults, obesity is associated with chronic low-grade inflammation, which may cause long-term adverse health consequences. We evaluated whether obesity in prepubertal children also generates this kind of inflammation and whether calprotectin and chemerin may be useful markers for early detection of such inflammation in this group of children. The study population included 83 children aged 2 to 10 years; 62 with obesity and without components of metabolic syndrome and 21 healthy controls with normal body weight. White blood cell (WBC) count, concentrations of C-reactive protein (CRP), interleukin-6 (IL-6), calprotectin, and chemerin were determined in peripheral blood. Our study showed that in the group with obesity, serum concentrations of calprotectin and chemerin, as well as CRP were significantly higher as compared with the controls. We found a significant positive correlation between serum chemerin concentrations and BMI z-score (r = 0.33, p < 0.01) in children with obesity. Chemerin concentration was also positively correlated with CRP level (r = 0.36, p < 0.01) in the whole group of children. These findings suggest that obesity may generate chronic low-grade inflammation as early as in the prepubertal period which can be indicated by significantly higher serum concentrations of calprotectin and chemerin. Calprotectin and especially chemerin seem to be promising indicators of this type of inflammation in children with obesity, but the correlation between these markers requires further research.

Post hoc analysis of fecal samples from responders and non-responders to Lactobacillus reuteri DSM 17938 intervention

We compared fecal samples from responders and non-responders to administration of Lactobacillus reuteri DSM 17938. Data for this post hoc analysis were collected from an RCT assessing the efficacy of L. reuteri for the management of acute gastroenteritis. Responders were defined as subjects with diarrhea lasting no longer than 48 h. 44 children (17 responders and 27 non-responders) were analyzed. There were no differences in clinical characteristics and gut colonization between both groups. In the responder group, there were significantly lower levels of five metabolites before beginning of the intervention: lactate, choline, ethanol, creatine, and formate. The fecal calprotectin level did not differ between groups prior to the intervention, but its level was significantly lower after intervention in the responder group. Possibly, the responder group with a "metabolic niche", including lower level of metabolites, especially lactate, that are potential products of Lactobacillus genus, would determine the response to probiotic treatment. These findings need to be confirmed, but identification of some differences in the fecal metabolomics and the calprotectin level suggests that further studies are warranted.

Ascitic Calprotectin as an early predictor of hepatocellular carcinoma in patients with cirrhotic ascites

BACKGROUND

Calprotectin is a heterodimer formed by S100A8 and S100A9 proteins which are enhanced during hepatic carcinogenesis and the increased expression of both proteins promotes malignant progression of hepatocellular carcinoma. The potential correlation between ascitic Calprotectin and HCC was not studied.

METHODS

100 patients were stratified into a case group which enrolled 50 patients with cirrhotic ascites and documented HCC and a control group consisted of 50 patients with cirrhotic ascites without HCC. They were evaluated by liver function tests, abdominal ultrasound and routine ascitic fluid examination including ascetic Calprotectin and results were validated in another group (n = 100).

RESULTS

Calprotectin level was significantly higher in the HCC group with insignificant difference regarding total cell count, PNLs, ascitic albumin, LDH, CEA and SAAG. It correlated with serum creatinine (r = 0.245, p = 0.014) and number of focal hepatic lesions (r = 0.309, p = 0.002). In the validation group, 28 patients had elevated ascitic Calprotectin of which 21 patients had developed HCC (75%) after a mean period of 3.8 ± 1.54 months. A cut of value 126 ng/ml was accurate to predict HCC in liver cirrhosis with ascites with a sensitivity of 93.3% specificity 94%, AUC 0.950, Youden's J value = 0.873, p = 0.0001.

CONCLUSION

Ascitic Calprotectin may offer an easy, affordable marker that can predict the early occurrence of HCC.