Plasma calprotectin and its association with cardiovascular disease manifestations, obesity and the metabolic syndrome in type 2 diabetes mellitus patients

A Prospective Study of the Association Between Plasma Calprotectin Levels and New-Onset CKD in the General Population

Introduction

Systemic inflammation has been associated with chronic kidney disease (CKD). In this study, we aimed to investigate a potential association between the plasma biomarker of inflammation calprotectin and new-onset CKD in a population-based cohort study.

Methods

Individuals without CKD at baseline (n = 4662) who participated in the Prevention of REnal and Vascular ENd-stage Disease (PREVEND) prospective population-based cohort study in the Netherlands were included. Baseline plasma calprotectin levels were assessed in samples that had been stored at -80 °C. Occurrence of new-onset CKD was defined as a composite outcome of an estimated glomerular filtration rate (eGFR) <60 ml/min per 1.73 m2, urinary albumin excretion (UAE) >30 mg/24h, or both.

Results

Baseline median (interquartile range) plasma calprotectin levels were 0.49 (0.35-0.68) mg/l and baseline median eGFR was 95.9 (interquartile range: 85.0-105.7) ml/min per 1.73 m2. After median follow-up of 8.3 (7.8-8.9) years, 467 participants developed new-onset CKD. Baseline plasma calprotectin levels were significantly associated with an increased risk of new-onset CKD (hazard ratio [HR] per doubling 1.28 [95% confidence interval, CI: 1.14-1.44], P < 0.001), independent of potentially confounding factors (HR 1.14 [95% CI: 1.01-1.29], P = 0.034), except for baseline high-sensitive C-reactive protein (hs-CRP) (HR 1.05 [0.91-1.21], P = 0.494). In secondary analyses, the association between plasma calprotectin and occurrence of UAE >30 mg/24h remained significant (HR 1.17 [1.02-1.34], P = 0.027), but not significantly so for the incidence of eGFR <60 ml/min per 1.73 m2 as individual outcome (HR 1.15 [0.92-1.43], P = 0.218).

Conclusion

Higher plasma calprotectin levels are associated with an increased risk of developing CKD in the general population. This association is mitigated after adjustment for hs-CRP, and more pronounced with new-onset CKD defined by UAE.

Role of Intestinal Inflammation and Permeability in Patients with Acute Heart Failure

Background and Objectives: Heart failure (HF) represents a major health burden. Although several treatment regimens are available, their effectiveness is often unsatisfactory. Growing evidence suggests a pivotal role of the gut in HF. Our study evaluated the prognostic role of intestinal inflammation and permeability in older patients with acute HF (AHF), and their correlation with the common parameters traditionally used in the diagnostic-therapeutic management of HF. Materials and Methods: In a single-center observational, prospective, longitudinal study, we enrolled 59 patients admitted to the Emergency Department (ED) and then hospitalized with a diagnosis of AHF, from April 2022 to April 2023. Serum routine laboratory parameters and transthoracic echocardiogram were assayed within the first 48 h of ED admission. Fecal calprotectin (FC) and both serum and fecal levels of zonulin were measured, respectively, as markers of intestinal inflammation and intestinal permeability. The combined clinical outcome included rehospitalizations for AHF and/or death within 90 days. Results: Patients with increased FC values (>50 µg/g) showed significantly worse clinical outcomes (p < 0.001) and higher median levels of NT-proBNP (p < 0.05). No significant correlation was found between the values of fecal and serum zonulin and the clinical outcome. Median values of TAPSE were lower in those patients with higher values of fecal calprotectin (p < 0.05). After multivariate analysis, NT-proBNP and FC values > 50 µg/g resulted as independent predictors of a worse clinical outcome. Conclusions: Our preliminary finding supports the hypothesis of a close relationship between the gut and heart, recognizing in a specific marker of intestinal inflammation such as FC, an independent predictive prognostic role in patients admitted for AHF. Further studies are needed to confirm these results, as well as investigate the reliability of new strategies targeted at modulation of the intestinal inflammatory response, and which are able to significantly impact the course of diseases, mainly in older and frail patients.

Serum Versus Fecal Calprotectin Levels in Patients with Severe Obesity Before and 6 Months After Roux-Y-Gastric Bypass: Report of the Prospective Leaky-Gut Study

INTRODUCTION

Obesity is associated with low-grade inflammation, including intestinal inflammation based on fecal or serum calprotectin (FC-SC) measurement. Roux-en-Y gastric bypass (RYGB) improves obesity-related parameters. However, the association between FC-SC levels and postoperative course and the link with metabolic and inflammatory phenotypes before and after RYGB remains unclear.

METHODS

We determined SC levels in 48 patients before (T0) and 6 months after (T6M) RYGB. We then analyzed postoperative changes in FC-SC levels and the relationship with inflammation and metabolic status.

RESULTS

Twenty-three patients (48%) had elevated SC levels (˃2.9 μg/mL) at T0 and T6M. Six of 29 patients (20.7%) had elevated FC concentrations (>50 μg/g) at T0 vs. 16 of 17 patients (94.1%) at T6M (p=0.006). At T0, FC levels correlated with BMI (Rho=0.63; p=0.001) and systemic inflammation (CRP: Rho=0.66, p=0.0006; IL-6: Rho=0.48, p=0.03; haptoglobin: Rho=0.75; p= 0.0006). SC tended to be positively associated with triglyceride levels (Rho=0.34; p=0.08), BMI (Rho=0.34; p=0.08), and inflammatory markers (CRP: Rho=0.33; p=0.09; IL-6: Rho=0.36; p=0.06). FC levels were associated with increased jejunal IL-17+CD8+ T-cell densities (Rho:0.90; p=0.0002). FC and SC were correlated together at T0 (Rho=0.83; p<0.001) but not at T6M. At T6M, SC decreased by 53.6%, whereas FC increased by 79.7%. SC and FC were not associated with any of the variables studied at T6M.

CONCLUSION

FC is a surrogate marker of systemic and intestinal inflammation and adiposity, whereas SC only tends to correlate with systemic inflammation. At 6 months after RYGB, SC-based systemic inflammation decreased, whereas FC-based intestinal inflammation increased. FC and SC levels follow different trajectories and are unrelated to improvements following bariatric surgery.

Hepcidin Reduction during Testosterone Therapy in Men with Type 2 Diabetes: A Randomized, Double-Blinded, Placebo-Controlled Study

High hepcidin is linked to low-grade inflammation and lower iron levels. The consequences of testosterone replacement therapy (TRT) on inflammation and the risk of cardiovascular disease (CVD) are undetermined. We investigate the effect of TRT on the inflammatory cardiovascular risk markers hepcidin-iron, fibroblast growth factor 23 (FGF23)-phosphate-klotho, and calprotectin pathways.

METHODS

A randomized, placebo-controlled, double-blinded study at an academic tertiary-care medical center. Interventions were testosterone gel (TRT, n = 20) or placebo gel (n = 19) for 24 weeks. We included 39 men (50-70 years) with type 2 diabetes (T2D) on metformin monotherapy with bioavailable testosterone levels <7.3 nmol/L. Body composition was assessed with DXA- and MRI-scans; the main study outcomes were serum hepcidin-iron, FGF23, phosphate, klotho, and calprotectin.

RESULTS

Hepcidin levels decreased during TRT (β = -9.5 ng/mL, p < 0.001), lean body mass (β = 1.9 kg, p = 0.001) increased, and total fat mass (β = -1.3 kg, p = 0.009) decreased compared to placebo. Delta hepcidin was not associated with changes in lean body mass or fat mass. Iron and the pathways of FGF23-phosphate-klotho and calprotectin were unchanged during TRT.

CONCLUSIONS

During TRT, the reduction in hepcidin was not associated with circulating iron levels, lean body mass, or fat mass; these findings suggested a direct anti-inflammatory effect of TRT and no indirect effect mediated through these factors.

Calprotectin is a contributor to and potential therapeutic target for vascular calcification in chronic kidney disease

Vascular calcification is an important risk factor for cardiovascular (CV) mortality in patients with chronic kidney disease (CKD). It is also a complex process involving osteochondrogenic differentiation of vascular smooth muscle cells (VSMCs) and abnormal deposition of minerals in the vascular wall. In an observational, multicenter European study, including 112 patients with CKD from Spain and 171 patients on dialysis from France, we used serum proteome analysis and further validation by ELISA to identify calprotectin, a circulating damage-associated molecular pattern protein, as being independently associated with CV outcome and mortality. This was confirmed in an additional cohort of 170 patients with CKD from Sweden, where increased serum calprotectin concentrations correlated with increased vascular calcification. In primary human VSMCs and mouse aortic rings, calprotectin exacerbated calcification. Treatment with paquinimod, a calprotectin inhibitor, as well as pharmacological inhibition of the receptor for advanced glycation end products and Toll-like receptor 4 inhibited the procalcifying effect of calprotectin. Paquinimod also ameliorated calcification induced by the sera of uremic patients in primary human VSMCs. Treatment with paquinimod prevented vascular calcification in mice with chronic renal failure induced by subtotal nephrectomy and in aged apolipoprotein E-deficient mice as well. These observations identified calprotectin as a key contributor of vascular calcification, and increased circulating calprotectin was strongly and independently associated with calcification, CV outcome, and mortality in patients with CKD. Inhibition of calprotectin might therefore be a promising strategy to prevent vascular calcification in patients with CKD.

Calprotectin in Patients with Rheumatic Immunomediated Adverse Effects Induced by Checkpoints Inhibitors

BACKGROUND

this is an exploratory study to evaluate calprotectin serum levels in patients with rheumatic immune-related adverse events (irAEs) induced by immune checkpoint inhibitor (ICI) treatment.

METHODS

this is a retrospective observational study including patients with irAEs rheumatic syndromes. We compared the calprotectin levels to those in a control group of patients with RA and with a control group of healthy individuals. Additionally, we included a control group of patients treated with ICI but without irAEs to check calprotectin levels. We also analysed the performance of calprotectin for the identification of active rheumatic disease using receiver operating characteristic curves (ROC).

RESULTS

18 patients with rheumatic irAEs were compared to a control group of 128 RA patients and another group of 29 healthy donors. The mean calprotectin level in the irAE group was 5.15 μg/mL, which was higher than the levels in both the RA group (3.19 μg/mL) and the healthy group (3.81 μg/mL) (cut-off 2 μg/mL). Additionally, 8 oncology patients without irAEs were included. In this group, calprotectin levels were similar to those of the healthy controls. In patients with active inflammation, the calprotectin levels in the irAE group were significantly higher (8.43 μg/mL) compared to the RA group (3.94 μg/mL). ROC curve analysis showed that calprotectin had a very good discriminatory capacity to identify inflammatory activity in patients with rheumatic irAEs (AUC of 0.864).

CONCLUSIONS

the results suggest that calprotectin may serve as a marker of inflammatory activity in patients with rheumatic irAEs induced by treatment with ICIs.

Effect of antiretroviral therapy on decreasing arterial stiffness, metabolic profile, vascular and systemic inflammatory cytokines in treatment-naïve HIV: A one-year prospective study

INTRODUCTION

Cardiovascular disease is a major cause of death among people living with HIV (PLH). Non-treated PLH show increased levels of inflammation and biomarkers of vascular activation, and arterial stiffness as a prognostic cardiovascular disease risk factor. We investigated the effect of one year of ART on treatment-naïve HIV(+) individuals on arterial stiffness and inflammatory and vascular cytokines.

METHODS

We cross-sectionally compared aortic stiffness via tonometry, inflammatory, and vascular serum cytokines on treatment-naïve (n = 20) and HIV (-) (n = 9) matched by age, sex, metabolic profile, and Framingham score. We subsequently followed young, treatment-naïve individuals after 1-year of ART and compared aortic stiffness, metabolic profile, and inflammatory and vascular serum biomarkers to baseline. Inflammatory biomarkers included: hs-CRP, D-Dimer, SAA, sCD163s, MCP-1, IL-8, IL-18, MRP8/14. Vascular cytokines included: myoglobin, NGAL, MPO, Cystatin C, ICAM-1, VCAM-1, and MMP9.

RESULTS

Treatment-naïve individuals were 34.8 years old, mostly males (95%), and with high smoking prevalence (70%). Baseline T CD4+ was 512±324 cells/mcL. cfPWV was similar between HIV(-) and treatment-naïve (6.8 vs 7.3 m/s; p = 0.16) but significantly decreased after ART (-0.52 m/s; 95% CI -0.87 to -0.16; p0.006). Almost all the determined cytokines were significantly higher compared to controls, except for MCP-1, myoglobin, NGAL, cystatin C, and MMP-9. At follow-up, only total cholesterol and triglycerides increased and all inflammatory cytokines significantly decreased. Regarding vascular cytokines, MPO, ICAM-1, and VCAM-1 showed a reduction. D-Dimer tended to decrease (p = 0.06) and hs-CRP did not show a significant reduction (p = 0.17).

CONCLUSION

One year of ART had a positive effect on reducing inflammatory and vascular cytokines and arterial stiffness.

Is canine calprotectin in serum stabile after storage at low temperature?

BACKGROUND

In human and veterinary medicine calprotectin is most widely used in diagnosing different gastro-intestinal diseases. The aim of this study was to assess the stability of canine calprotectin (cCP) in serum after storage at low temperatures and imprecision of the method.

METHODS

Blood samples were collected from dogs with different clinical diagnoses. Twenty-two dogs were included in this study. Calprotectin concentration was measured 4 hours after serum separation (T0), and after being frozen at - 80 °C for 8 (T1) and 16 weeks (T2). The maximum permissible difference (MPD) was derived from the equation for calculating total error (TE) TE = %Bias + (1.96 x %CV), where bias and coefficient of variation (CV) were defined by the manufacturer. The dogs enrolled in this study were patients admitted during the morning (9-12 a.m.), on the day the first measurement was performed. All sample analysis for determination of stability were done in duplicates. For determination of within-run precision, the two patients' serum samples were analyzed in 20 replicates. Imprecision was assessed by analyzing 20 replicates on one plate on two samples where high and low concentrations were anticipated.

RESULTS

The calculated value of MPD was 32.52%. Median calprotectin concentrations were higher at T1 114.08 μg/L (IQR = 55.05-254.56) and T2 133.6 μg/L (IQR = 100.57-332.98) than at T0 83.60 μg/L (IQR = 50.38-176.07). Relative and absolute bias at T1 (49.3%; 45.98 μg/L) and T2 (109.93%; 94.09 μg /L) have shown that calprotectin concentrations increase after long term storage at - 80 °C.

CONCLUSION

The results of the present study indicate that c-CP was not stable for 16 weeks at low storage temperature (- 80 °C). Considering the observed change in the concentration of c-CP at T1, a storage time of 8 weeks should be safely applied. The method imprecision was not satisfactory, especially in the lower concentration range.

Calprotectin as a Biomarker for Diagnosis and Severity of Acute Noninfectious Anterior Uveitis in Egyptian Patients

PURPOSE

To study the relation between serum calprotectin level and acute noninfectious anterior uveitis in Egyptian patients.

METHODS

An observational prospective study carried out at Menoufia University Hospital during the period from March 2021 till June 2022, after informed consent from all studied patients. This study included 20 eyes of patients with Acute Anterior Uveitis (AAU) and 20 eyes healthy individuals matched sex and age as the control group. Full history taking, ophthalmological examination and serum calprotectin levels were performed for both patients and controls.

RESULTS

Serum calprotectin levels were substantially higher in patients' eyes with acute anterior uveitis than in healthy eyes (61.45±7.89 vs 32.50±11.64; 95% CI: 22.58-35.32; P < 0.001). ROC curve analysis showed that the cut-off point of serum calprotectin in severity detection of AAU was ≥58.0, with sensitivity of 95%, specificity of 43% at AUC of 0.986, with reached to significant level (p < 0.001).

CONCLUSION

Serum calprotectin levels were significantly elevated with positive previous uveitis and marked grade indicating a possible role of calprotectin in the pathogenesis of non-infectious AAU. The serum calprotectin cut-off points for severity detection of AAU were 58.0, with sensitivity of 95% and specificity of 43%. Finally, we identified serum calprotectin as a potential biomarker for detection of anterior uveitis severity and patients' morbidity risk. Further investigation with large sample size is needed to assess the relationship between calprotectin and uveitis activity.

From bench to bedside: Calprotectin (S100A8/S100A9) as a biomarker in rheumatoid arthritis

S100A9/S100A8 (calprotectin), a member of the S100 protein family, has been shown to play a pivotal role in innate immunity activation. Calprotectin plays a critical role in the pathogenesis of rheumatoid arthritis (RA), as it triggers chemotaxis, phagocyte migration and modulation of neutrophils and macrophages. Higher calprotectin levels have been found in synovial fluid, plasma, and serum from RA patients. Recent studies have demonstrated better correlations between serum or plasma calprotectin and composite inflammatory disease activity indexes than c-reactive protein (CRP) or the erythrocyte sedimentation rate (ESR). Calprotectin serum levels decreased after treatment, independently of the DMARD type or strategy. Calprotectin has shown the strongest correlations with other sensitive techniques to detect inflammation, such as ultrasound. Calprotectin independently predicts radiographic progression. However, its value as a biomarker of treatment response and flare after tapering is unclear. This update reviews the current understanding of calprotectin in RA and discusses possible applications as a biomarker in clinical practice.

Plasma calprotectin - preanalytical stability and interference from hemolysis

As an activation product of neutrophil granulocytes, calprotectin has been widely used in fecal samples for diagnosis and monitoring of patients with inflammatory bowel disease. However, fecal sample collection is cumbersome, and pre-analytical sources of error are plentiful. Therefore, plasma calprotectin is being investigated as a promising new biomarker. To utilize any biomarker, pre-analytical factors such as stability and susceptibility to interference from hemolysis must be established. We present precision estimates, stability results as well as interference study on plasma calprotectin in EDTA-plasma using the Thermo Fischer Phadia 250 EliA^TM Calprotectin immunoassay. Precision was estimated by the use of patient pools as well as internal quality controls provided by the manufacturer. Coefficients of variance were below 6.9% for patient samples. Calprotectin was stable in EDTA plasma after storage at 5-8 °C for up to 4 days, as well as after long-term storage at -20 °C. Susceptibility to interference from hemolysis was high, especially for low concentrations of calprotectin (<50 ng/mL) where hemoglobin levels above 0.02 mmol/L lead to false increase in calprotectin concentrations of up to 100%.

Analytical and clinical evaluation of DiaSorin Liaison® Calprotectin fecal assay adapted for serum samples

Background

Calprotectin is a calcium‐binding protein that can be measured in serum, plasma, and feces. Increased serum and plasma calprotectin concentrations have been found in chronic inflammatory rheumatic disorders. An analytical and clinical evaluation of the DiaSorin Liaison® fecal Calprotectin assay using LIAISON® XL was performed.

Methods

The protocol included an analytical and clinical evaluation in which imprecision, the linearity of dilution, differences between serum and plasma samples and method comparison with CalproLab™ ELISA kit were assessed. Serum calprotectin concentrations in active (n = 26) and remission (n = 23) rheumatoid arthritis (RA) patients were compared.

Results

The intra‐day and inter‐day analytical imprecision CVs ranged from 2.9% to 4.0% and 2.7% to 10.4%, respectively. Correlation between measured and expected values was high (R > 0.99), indicating good linearity. The Wilcoxon signed‐rank test showed that serum and plasma matched samples presented statistically significant differences (p < 0.001) being the highest concentrations of calprotectin observed in serum samples. Deming regression equation was as follows: Diasorin calprotectin (μg/ml) = −0.32 (95% CI: −0.65 ‐ −0.05) +1.58 (95% CI: 1.42–1.79).* Calprolab calprotectin (μg/ml). Significantly higher serum calprotectin levels were found in RA patients with active disease when compared to patients with low disease activity or in clinical remission (mean ± SD) [(3.35 μg/ml ± 1.55) vs. (1.63 μg/ml ± 0.52), p < 0.001] and these levels correlated well with all disease activity indices.

Conclusions

The DiaSorin Liaison® fecal Calprotectin assay adapted for serum samples showed adequate technical performances and the clinical performances were similar to other assays.

Serum Calprotectin as a Blood-Based Biomarker for Monitoring Knee Osteoarthritis at Early but Not Late Stages

OBJECTIVE

The identification of early-stage osteoarthritis (OA) is crucial for the deceleration of its progression; however, no reliable biomarker is available for this purpose. The current study aimed to determine the role of serum calprotectin in the detection of early-stage knee OA.

DESIGN

In a case-control study, serum samples were collected from 84 patients with primary bilateral knee OA and 52 healthy controls. The radiographic grading of knee OA was performed using the Kellgren-Lawrence classification system. Serum concentrations of calprotectin were measured using an enzyme-linked immunosorbent assay.

RESULTS

The mean serum calprotectin level was 2908 ± 2516 ng/mL in OA patients and 901 ± 875 ng/mL in healthy control subjects (P < 0.001). Mean serum calprotectin levels were significantly higher in the lower stages of OA: 3740 ± 2728 ng/mL in OA grade I, 3100 ± 2084 ng/mL in OA grade II, 2246 ± 1418 ng/mL in OA grade III, and 2035 ± 765 ng/mL in OA grade IV (P = 0.047). Serum calprotectin levels were significantly higher in patients with a disease duration <42 months compared with those with a disease duration >42 months (P = 0.043).

CONCLUSION

Serum calprotectin level increases significantly in the early stages of OA and shows a reverse association with disease severity. Therefore, it could be suggested as a promising blood-based marker for early-stage knee OA.

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.

Inflammatory markers and risk of cardiovascular mortality in relation to diabetes status in the HUNT study

Inflammatory markers have been associated with increased risk of cardiovascular mortality in general populations. We assessed whether these associations differ by diabetes status. From a population-based cohort study (n = 62,237) we included all participants with diabetes (n = 1753) and a control group without diabetes (n = 1818). Cox regression models were used to estimate hazard ratios (HRs) with 95% confidence intervals (CI) for possible associations with cardiovascular mortality of 4 different inflammatory markers; C-reactive protein (CRP), calprotectin, neopterin and lactoferrin. During a median follow-up of 13.9 years, 728 (20.4%) died from cardiovascular disease (CVD). After adjustment for age, sex and diabetes, the associations of all inflammatory markers with risk of cardiovascular mortality were log-linear (all P ≤ 0.017 for trend) and did not differ according to diabetes status (all P ≥ 0.53 for interaction). After further adjustments for established risk factors, only CRP remained independently associated with cardiovascular mortality. HRs were 1.22 (1.12-1.32) per standard deviation higher loge CRP concentration and 1.91 (1.50-2.43) when comparing individuals in the top versus bottom quartile. The associations of CRP, calprotectin, lactoferrin and neopterin with cardiovascular mortality did not differ by diabetes, suggesting that any potential prognostic value of these markers is independent of diabetes status.

Association of serum calprotectin with peripheral neuropathy in patients with type 2 diabetes mellitus

Introduction

Peripheral neuropathy is a common microvascular complication in patients with type 2 diabetes mellitus with a prevalence of around 50%.

Objectives

This prospective observational cross-sectional study was done to assess serum calprotectin levels among diabetic patients with peripheral neuropathy as compared to those without neuropathy.

Methods

This cross-sectional study was conducted in 126 diabetic patients attending the out-patient department of JIPMER Hospital, Pondicherry from July 2017 to January 2019. The subjects were divided into two groups (with and without peripheral neuropathy) and underwent nerve conduction study of both the lower limbs. Blood samples were collected and stored at -80°C for estimation of serum calprotectin. Serum calprotectin levels were compared between diabetic patients with and without peripheral neuropathy.

Results

Serum calprotectin levels were increased in patients with diabetic peripheral neuropathy (DPN) as compared to those without DPN. However, there was no significant difference in the mean value of serum calprotectin among the various sub-groups of DPN.

Conclusion

Serum calprotectin, an inflammatory biomarker is elevated in patients with diabetic peripheral neuropathy as compared to those without neuropathy.

The Role of Serum Calprotectin as a New Marker in Abdominal Aortic Aneurysms - A Preliminary Report

BACKGROUND

Abdominal Aortic Aneurysm (AAA) remains a surgical challenge. There are many recognizable markers associated with the formation of AAA. Previous experiments carried out on animal models have shown a correlation between serum calprotectin and the occurrence of AAA.

OBJECTIVE

This study aimed to evaluate the level of calprotectin as a potential diagnostic biomarker in patients with diagnosed AAA.

METHODS

The study group consisted of 75 patients aged 35-75 years assigned to two groups: a control group (n=43) of healthy subjects without AAA and a study group (n=32) of patients with a diagnosed AAA. The first calprotectin test was performed upon patient admission to the hospital, and the second control test was performed after three months. The concentration of calprotectin in plasma was determined using the Immunoenzymatic Method (ELISA) with the commercially available Assaypro Kit (AssayMax™ Human Calprotectin ELISA Kit), as well as the sandwich method with polyclonal antibodies to human calprotectin and peroxidase enzyme.

RESULTS & DISCUSSION

Serum calprotectin levels in AAA patients were three times higher than in healthy subjects (p<0.05). A statistically significant twofold decrease in calprotectin concentration was observed after AAA surgery compared to the control group (p<0.05).

CONCLUSION

Calprotectin levels can be an important marker in the detection of AAA. In conclusion, AAA patients showed a threefold increase in serum calprotectin level and a twofold decrease in this marker after AAA surgery.

Gut Alterations in Septic Patients: A Biochemical Literature Review

BACKGROUND

Sepsis is a life-threatening organ dysfunction with high mortality and morbidity rate and with the disease progression many alterations are observed in different organs. The gastrointestinal tract is often damaged during sepsis and septic shock and main symptoms are related to increased permeability, bacterial translocation and malabsorption. These intestinal alterations can be both cause and effect of sepsis.

OBJECTIVE

The aim of this review is to analyze different pathways that lead to intestinal alteration in sepsis and to explore the most common methods for intestinal permeability measurement and, at the same time to evaluate if their use permit to identify patients at high risk of sepsis and eventually to estimate the prognosis.

MATERIAL AND METHODS

The peer-reviewed articles analyzed were selected from PubMed databases using the keywords "sepsis" "gut alteration", "bowel permeability", "gut alteration", "bacterial translocation", "gut permeability tests", "gut inflammation". Among the 321 papers identified, 190 articles were selected, after title - abstract examination and removing the duplicates and studies on pediatric population,only 105 articles relating to sepsis and gut alterations were analyzed.

RESULTS

Integrity of the intestinal barrier plays a key role in the preventing of bacterial translocation and gut alteration related to sepsis. It is obvious that this dysfunction of the small intestine can have serious consequences and the early identification of patients at risk - to develop malabsorption or already malnourished - is very recommended to increase the survivor rate. Until now, in critical patients, the dosage of citrullinemia is easily applied test in clinical setting, in fact, it is relatively easy to administer and allows to accurately assess the functionality of enterocytes.

CONCLUSION

The sepsis can have an important impact on the gastrointestinal function. In addition, the alteration of the permeability can become a source of systemic infection. At the moment, biological damage markers are not specific, but the dosage of LPS, citrulline, lactulose/mannitol test, FABP and fecal calprotectin are becoming an excellent alternative with high specificity and sensitivity.

The Role of Plasma Calprotectin in Non-infectious Uveitis

PURPOSE

To investigate the role of plasma calprotectin in non-infectious uveitis.

METHODS

This is an observational both cross-sectional and prospective study. Patients with active non-infectious uveitis were recruited as well as nonuveitic controls. Plasma calprotectin was determined and an ophthalmological examination was performed for both patients and controls. Independent variables possibly influencing levels of plasma calprotectin were recorded and analyzed. Categorical variables were compared by chi-square test (applying correction by continuity if necessary). T-test (or Kruskal-Wallis when appropriate) was used to compare averages. Multiple linear regression analysis was used to assess relationship between plasma calprotectin levels and independent variables. Spearman coefficient was calculated in order to establish correlation between plasma calprotectin and anterior chamber cell grading. Changes in plasma calprotectin levels between the flare beginning and its resolution were determined with mixed model for repeated measures. R software (version 3.6.0) was used to perform the statistical analysis.

RESULTS

We included 74 patients and 40 controls in the cross-sectional study. Plasma calprotectin levels were higher in uveitis patients compared to those of controls (p = .003), being higher in younger patients and patients with posterior uveitis. No correlation between calprotectin and anterior chamber inflammation degree was found (p = .198). For the prospective study, we included 36 patients. We found no significant differences in calprotectin levels between active and inactive uveitis (p = .344).

CONCLUSIONS

Plasma calprotectin levels are elevated in uveitis patients and are influenced by age and anatomical location of uveitis. Further investigation is needed to assess the relationship between calprotectin and uveitis activity.

Global gene methylation profiling of common warts caused by human papillomaviruses infection

Infection with the human papillomaviruses (HPV) often involves the epigenetic modification of the host genome. Despite its prevalence among the population, host genome methylation in HPV-induced warts is not clearly understood. In this study, genome-wide methylation profiling was carried out on paired healthy skin and wart samples in order to investigate the effects that benign HPV infection has on gene methylation status. To overcome this gap in knowledge, paired wart (n = 12) and normal skin (n = 12) samples were obtained from Arab males in order to perform DNA extraction and subsequent genome-wide methylation profiling on the Infinium Methylation EPIC Bead Chip microarray. Analysis of differential methylation revealed a clear pattern of discrimination between the wart and normal skin samples. In warts, the most differentially methylated (DM) genes included long non-coding RNAs (AC005884, AL049646.2, AC126121.2, AP001790.1, and AC107959.3), microRNAs (MIR374B, MIR596, MIR1255B1, MIR26B, and MIR196A2),snoRNAs (SNORD114-22, SNORD70, and SNORD114-31), pseudogenes (AC069366.1, RNU4ATAC11P, AC120057.1, NANOGP3, AC106038.2, TPT1P2, SDC4P, PKMP3, and VN2R3P), and protein-coding genes (AREG, GJB2, C12orf71, AC020909.2, S100A8, ZBED2, FABP7, and CYSLTR1). In addition, pathway analysis revealed that, among the most differentially methylated genes, STAT5A, RARA, MEF2D, MAP3K8, and THRA were the common regulators. It can be observed that HPV-induced warts involve a clear and unique epigenetic alteration to the host genome.

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

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

Determinants of Increased Serum Calprotectin in Patients with Type 2 Diabetes Mellitus

Circulating calprotectin is a potential biomarker for endovascular inflammation in type 2 diabetes mellitus (T2DM). We investigated the determinants of calprotectin and its relationship with the presence of cardiovascular disease (CVD) in 362 T2DM patients included in the Diabetes and Lifestyle Cohort Twente-1 (DIALECT-1) study. Lifestyle exposures, including nutrition, were determined by validated questionnaires. CVD was defined as coronary artery diseases, strokes, and peripheral artery diseases. Median serum calprotectin levels were 1.04 mg/L [IQR: 0.73-1.46 mg/L] and were higher in women (1.11 mg/L) than men (0.96 mg/L, p = 0.007). Current smoking was a major independent determinant of circulating calprotectin, with a 51% higher calprotectin compared to never smoking (p < 0.001). Albuminuria (p = 0.011), former smoking (p = 0.023), and intake of mono- and disaccharides (p = 0.005) also contributed independently to circulating calprotectin. Each incremental increase in calprotectin level was associated with 1.36-times higher odds for CVD (95% CI 1.04-1.77, p = 0.026). In the current study, calprotectin was the only inflammatory parameter significantly associated with CVD. The strong association of circulating calprotectin with smoking, a well-known direct cause of vascular inflammation, and also with CVD, stresses the urge for further research to define its role as a biomarker in T2DM.

Prognostic value of serum calprotectin level in elderly diabetic patients with acute coronary syndrome undergoing percutaneous coronary intervention: A Cohort study

Patients with acute coronary syndrome (ACS) have an increased serum level of calprotectin. The purpose of present study was to analyze the prognostic significance of serum calprotectin levels in elderly diabetic patients underwent percutaneous coronary intervention (PCI) due to ACS.A total of 273 consecutive elderly diabetic patients underwent PCI for primary ACS were enrolled. Serum calprotectin levels were measured before PCI, and baseline clinical characteristics of all patients were collected. All patients were followed up at regular interval for major adverse cardiovascular events (MACEs) during 1 year after PCI. MACEs include cardiovascular death, nonfatal myocardial infarction, and target vessel revascularization (TVR). The predicting value of serum calprotectin for MACEs was analyzed by using univariate and multivariate analysis and receiver-operating characteristic curve (ROC).At the endpoint of this study, 47 patients of all 273 patients had MACEs. According to optimal cutoff value of calprotectin for predicting MACEs by ROC analysis, all patients were stratified into a high calprotectin group and a low calprotectin group. The incidence rate of MACEs and TVR in high calprotectin group was prominently higher than that in low calprotectin group (21.9% vs 11.5%, P = .02). In multivariable COX regression analysis adjusting for potential confounders, serum calprotectin level remains as an independent risk predictor of MACE (hazard ratio, 1.56; 95% confidence interval [CI]: 1.08-4.62; P = .01).In diabetic patients with a comorbidity of ACS, a high serum level of calprotectin is associated to a higher MACE rate after PCI.

Increase of Neutrophil Activation Markers in Venous Thrombosis-Contribution of Circulating Activated Protein C

Upon activation, neutrophils release their content through different mechanisms like degranulation and NETosis, thus prompting thrombosis. The natural anticoagulant activated protein C (APC) inhibits neutrophil NETosis and, consequently, this may lower the levels of neutrophil activation markers in plasma, further diminishing the thrombotic risk exerted by this anticoagulant. We aimed to describe the status of markers of neutrophil activation in plasma of patients with venous thrombosis, their association with the thrombotic risk and the potential contribution of APC. We quantified three markers of neutrophil activation (cell-free DNA, calprotectin, and myeloperoxidase) in 253 patients with venous thromboembolism (VTE) in a stable phase (192 lower extremity VTE and 61 splanchnic vein thrombosis) and in 249 healthy controls. In them, we also quantified plasma APC, soluble endothelial protein C receptor (EPCR), and soluble thrombomodulin (TM), and we genotyped two genetic regulators of APC: the EPCR gene (PROCR) haplotypes (H) and the TM gene (THBD) c.1418C>T polymorphism. We found a significant increase in plasma cell-free DNA (p < 0.0001), calprotectin (p = 0.0001) and myeloperoxidase (p = 0.005) in VTE patients compared to controls. Furthermore, all three neutrophil activation markers were associated with an increase in the thrombotic risk. Cell-free DNA and calprotectin plasma levels were significantly correlated (Spearman r = 0.28; p < 0.0001). As expected, the natural anticoagulant APC was significantly decreased in VTE patients (p < 0.0001) compared to controls, what was mediated by its genetic regulators PROCR-H1, PROCR-H3, and THBD-c.1418T, and inversely correlated with cell-free DNA levels. This is the largest case-control study that demonstrates the increase in markers of neutrophil activation in vivo in VTE patients and their association with an increased thrombotic risk. This increase could be mediated by low APC levels and its genetic regulators, which could also increase NETosis, further enhancing thrombosis and inflammation.

The Impact of Psoriasis and Metabolic Syndrome on the Systemic Inflammation and Oxidative Damage to Nucleic Acids

BACKGROUND

Psoriasis is a chronic systemic inflammatory disease associated with a wide range of comorbidities, including metabolic syndrome (MetS). Serum calprotectin, ANGPTL8, and oxidative damage to nucleic acids might be associated with both diseases. The presented study describes the influence of psoriasis and MetS on the serum levels of markers of systemic inflammation (calprotectin and ANGPTL8) and markers of oxidative damage to nucleic acids. The applicability of serum levels of calprotectin and ANGPTL8 for monitoring of the activity of psoriasis (diagnostic markers) is also evaluated.

METHODS

Clinical examination (PASI score, MetS), enzyme-linked immunosorbent assay (ELISA), and Enzyme Immunoassay (EIA). Serum calprotectin, ANGPTL8, 8-hydroxy-2'-deoxyguanosine, 8-hydroxyguanosine, and 8-hydroxyguanine. Results and Conclusions. The psoriasis significantly increased the serum level of calprotectin and the serum level of oxidative damage to nucleic acids, however not the serum level of ANGPTL8. The presence of MetS did not significantly affect the serum levels of calprotectin, ANGPTL8, and oxidative damage to nucleic acids in either psoriasis patients or controls. It seems that the serum level of calprotectin (but not the serum level of ANGPTL8) could be used as a biomarker for monitoring the activity of psoriasis.

Gut Microbiome, Intestinal Permeability, and Tissue Bacteria in Metabolic Disease: Perpetrators or Bystanders?

The emerging evidence on the interconnectedness between the gut microbiome and host metabolism has led to a paradigm shift in the study of metabolic diseases such as obesity and type 2 diabetes with implications on both underlying pathophysiology and potential treatment. Mounting preclinical and clinical evidence of gut microbiota shifts, increased intestinal permeability in metabolic disease, and the critical positioning of the intestinal barrier at the interface between environment and internal milieu have led to the rekindling of the "leaky gut" concept. Although increased circulation of surrogate markers and directly measurable intestinal permeability have been linked to increased systemic inflammation in metabolic disease, mechanistic models behind this phenomenon are underdeveloped. Given repeated observations of microorganisms in several tissues with congruent phylogenetic findings, we review current evidence on these unanticipated niches, focusing specifically on the interaction between gut permeability and intestinal as well as extra-intestinal bacteria and their joint contributions to systemic inflammation and metabolism. We further address limitations of current studies and suggest strategies drawing on standard techniques for permeability measurement, recent advancements in microbial culture independent techniques and computational methodologies to robustly develop these concepts, which may be of considerable value for the development of prevention and treatment strategies.

Analysis of Faecal Zonulin and Calprotectin Concentrations in Healthy Children During the First Two Years of Life. An Observational Prospective Cohort Study

Factors affecting the intestinal-barrier permeability of newborns, such as body mass index (BMI), nutrition and antibiotics, are assumed to affect intestinal-barrier permeability in the first two years of life. This study assessed 100 healthy, full-term newborns to 24 months old. Faecal zonulin/calprotectin concentrations were measured at 1, 6, 12, 24 months as gut-permeability markers. Zonulin concentrations increased between 1 and 12 months (medians: 114.41, 223.7 ng/mL; respectively), whereas calprotectin concentrations decreased between one and six months (medians: 149. 29, 109.28 µg/mL); both then stabilized (24 months: 256.9 ng/mL zonulin; 59.5 µg/mL calprotectin). In individual children, high levels at one month gave high levels at older ages (correlations: calprotectin: between 1 and 6 or 12 months: correlation coefficient (R) = 0.33, statistical significance (p) = 0.0095; R = 0.28, p = 0.032; zonulin: between 1 and 24 months: R = 0.32; p = 0.022, respectively). Parameters which gave marker increases: antibiotics during pregnancy (calprotectin; six months: by 80%, p = 0.038; 12 months: by 48%, p = 0.028); vaginal birth (calprotectin: 6 months: by 140%, p = 0.005); and > 5.7 pregnancy-BMI increase (zonulin: 12 months: by 74%, p = 0.049). Conclusions: “Closure of the intestines” is spread over time and begins between the sixth and twelfth month of life. Antibiotic therapy, BMI increase > 5.7 during pregnancy and vaginal birth are associated with increased intestinal permeability during the first two years of life. Stool zonulin and calprotectin concentrations were much higher compared with previous measurements at older ages; clinical interpretation and validation are needed (no health associations found).

Neutrophil Extracellular Traps in Tissue and Periphery in Juvenile Dermatomyositis

OBJECTIVE

Neutrophils are key immune cells participating in host defense through several mechanisms, including the formation of neutrophil extracellular traps (NETs). This study was undertaken to investigate the role of neutrophils in juvenile dermatomyositis (JDM).

METHODS

Electron microscopy was used to identify neutrophils in tissue. NETs were also imaged using fluorescence microscopy and quantified using a myeloperoxidase-DNA enzyme-linked immunosorbent assay (ELISA) in plasma obtained from healthy children (n = 20), disease controls (n = 29), JDM patients (n = 66), and JDM patients with history of calcifications (n = 20). Clinical data included disease activity scores and complement C4 levels. Levels of immune complexes (ICs) and calprotectin were analyzed using ELISA.

RESULTS

Using electron microscopy, neutrophils were found to infiltrate affected muscle tissue, engulfing deposited calcium crystals. Uptake of the crystals led to neutrophil activation (P < 0.01) and subsequent phosphatidylinositol 3-kinase- and NADPH oxidase-dependent but peptidylarginine deiminase 4-independent formation of NETs, which contained mitochondrial DNA (P < 0.05), as confirmed in vivo (P < 0.001) and in vitro (P < 0.01). Peripheral NET levels were associated with calcinosis (P = 0.01), ICs (P = 0.008), and interleukin-8 levels (P = 0.004). Children with JDM had impaired NET clearance (P = 0.01), associated with autoantibody profiles including melanoma differentiation-associated protein 5 (P = 0.005), and depressed complement C4 levels (r = -0.72, P = 0.002). Furthermore, children with JDM showed evidence of neutrophil activation, with elevated levels of peroxidase activity (P = 0.02) and calprotectin (P < 0.01), which were associated with disease activity (P = 0.007), and dyslipidemia (odds ratio 4.7, P < 0.05).

CONCLUSION

We found novel mechanisms of both calcium crystal-mediated neutrophil activation and cell death in JDM pathophysiology. Targeting this pathway may reduce the frequency and extent of calcinosis, as well as prevent long-term development of comorbidities, including atherosclerosis.

Serum Calprotectin Levels and Outcome Following Percutaneous Coronary Intervention in Patients with Diabetes and Acute Coronary Syndrome

Background

A retrospective study of data from a prospective clinical registry was conducted to evaluate the prognostic role of serum calprotectin in patients with diabetes who underwent percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS).

Material/Methods

Data were retrieved for 273 patients with diabetes mellitus who underwent PCI for primary ACS in a single center. Serum calprotectin levels were measured before PCI. Baseline clinical data included the Global Registry of Acute Coronary Events (GRACE) risk score for ACS. All patients underwent regular follow-up for major adverse cardiovascular events (MACE) during 12 months after PCI, including target vessel revascularization (TVR), defined as the need for an unplanned repeat PCI or coronary artery procedure. The predictive value of serum calprotectin for MACE was analyzed by using univariate and multivariate analysis and receiver operating characteristic (ROC) curve analysis.

Results

At the final follow-up, 47 of the 273 patients studies experienced MACE. Optimal cutoff values for serum calprotectin levels predictive for MACE stratified patients into a high calprotectin group and a low calprotectin group. The incidence of MACE and TVR in the high calprotectin group was significantly greater than in the low calprotectin group (21.9% vs. 11.5%; P=0.02). Multivariate analysis, adjusted for confounders, showed that the serum level of calprotectin was an independent risk factor for MACE (HR, 1.56; 95% CI, 1.08–4.62; P=0.01).

Conclusions

In patients with diabetes and the co-morbidity of ACS, a high serum level of calprotectin was associated with a significantly increased risk for MACE following PCI.

The Role of Inflammation in the Endothelial Dysfunction in a Cohort of Pediatric Patients With Inflammatory Bowel Disease

OBJECTIVES

Chronic inflammation plays a central role in the etiology of endothelial damage. Endothelial dysfunction (ED) is the inability of the artery to dilate in response to an endothelial stimulus. We assessed the ED by measuring the reactive hyperaemia index (RHI) and the flow-mediated dilation (FMD) in a cohort of pediatric patients affected by inflammatory bowel disease (IBD) and comparing these parameters to a group of healthy controls (HC).

METHODS

Forty-one patients were consecutive enrolled. ED was evaluated by both the plethysmographic RHI method and the measurement of the FMD of brachial artery after occlusion of the blood flow. Differences between patients and controls were assessed by the Mann-Whitney test. In each patient with IBD, the main inflammation markers were detected and correlated to RHI and FMD by a linear regression test.

RESULTS

We enrolled 26 (59%) patients with IBD and 18 (41%) HC. When comparing FMD value at diagnosis it was significantly lower in IBD patients than in HC (P = 0.04). This result was confirmed at follow-up, when this difference became even more significant (P = 0.004). A significant indirect correlation was found between FMD and fecal calprotectin (r: 0.17; P = 0.04). No differences were found when comparing RHI.

CONCLUSIONS

Our results suggest that inflammation could lead to ED assessed by ultrasound FMD. These data were not confirmed by RHI; however, this could be due to the lack of a standardized pediatric cut-off. More studies are necessary to confirm our data.

Hesperidin ameliorates insulin resistance by regulating the IRS1-GLUT2 pathway via TLR4 in HepG2 cells

The aim of this study was to evaluate the effect and mechanism of hesperidin (HES) on insulin resistance (IR) in the human hepatocellular carcinoma cell line (HepG2 cells). HepG2 cells were induced with lipopolysaccharide (LPS) as a model of IR and treated with HES at three dosages. Next, the levels of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), the glucose content, and glucose uptake were evaluated by enzyme-linked immunosorbent assay, glucose oxidase-peroxidase method (GOD-POD), or (2-(N-(7-nitrobenz-2-oxa-1, 3-diazol-4-yl)amino)-2-deoxyglucose) (2-NBDG). Moreover, the protein expression of toll-like receptors 4 (TLR4), insulin receptor substrate 1 (IRS1), nuclear factor kappa B (NF-κB), and glucose transporter 2 (GLUT2) in HepG2 cells treated with HES were assessed via western blotting analysis. In addition, GLUT2 protein expression exposed to HES was detected following treatment with TLR4 inhibitor (HTA125). Our results demonstrated that HES decreased the levels of TNF-α and IL-6, attenuated the glucose content in culture medium and increased glucose uptake in insulin-resistant HepG2 cells in vitro. Moreover, HES upregulated the expression of IRS1 and GLUT2 protein and downregulated the protein expression of TLR4 and NF-κB in insulin-resistant HepG2 cells. The expression of GLUT2 protein had no significant changes when treated with HES after blockade of TLR4. HES attenuated IR in LPS-inducedinsulin-resistant HepG2 cells. Therefore, regulating the IRS1-GLUT2 pathway via TLR4 represents a potential mechanism of HES on IR in HepG2 cells.

The Influence of Maternal-Foetal Parameters on Concentrations of Zonulin and Calprotectin in the Blood and Stool of Healthy Newborns during the First Seven Days of Life. An Observational Prospective Cohort Study

Background: It can be hypothetically assumed that maternal and perinatal factors influence the intestinal barrier. Methods: The study was conducted with 100 healthy, full-term newborns breastfed in the first week of life, with similar analyses for their mothers. Zonulin and calprotectin levels were used as intestinal permeability markers. Results: The median (range) zonulin concentrations (ng/mL) were in mothers: serum, 21.39 (6.39–57.54); stool, 82.23 (42.52–225.74); and newborns: serum cord blood, 11.14 (5.82–52.34); meconium, 54.15 (1.36–700.65); and stool at age seven days, 114.41 (29.38–593.72). Calprotectin median (range) concentrations (µg/mL) in mothers were: stool, 74.79 (3.89–211.77); and newborns: meconium, 154.76 (6.93–8884.11); and stool at age seven days 139.12 (11.89–627.35). The use of antibiotics during pregnancy resulted in higher zonulin concentrations in umbilical-cord serum and calprotectin concentrations in newborn stool at seven days, while antibiotic therapy during labour resulted in higher zonulin concentrations in the stool of newborns at seven days. Zonulin concentrations in the stool of newborns (at seven days) who were born via caesarean section were higher compared to with vaginal birth. With further analyses, caesarean section was found to have a greater effect on zonulin concentrations than prophylactic administration of antibiotics in the perinatal period. Pregnancy mass gain >18 kg was associated with higher calprotectin concentrations in maternal stool. Body Mass Index (BMI) increase >5.7 during pregnancy was associated with decreased zonulin concentrations in maternal stool and increased calprotectin concentrations in stool of mothers and newborns at seven days. There was also a negative correlation between higher BMI increase in pregnancy and maternal zonulin stool concentrations and a positive correlation between BMI increase in pregnancy and maternal calprotectin stool concentrations. Conclusion: Maternal-foetal factors such as caesarean section, antibiotic therapy during pregnancy, as well as change in mother’s BMI during pregnancy may increase intestinal permeability in newborns. Changes in body mass during pregnancy can also affect intestinal permeability in mothers. However, health consequences associated with increased intestinal permeability during the first days of life are unknown. Additionally, before the zonulin and calprotectin tests can be adopted as universal diagnostic applications to assess increased intestinal permeability, validation of these tests is necessary.

Association of circulating calprotectin with lipid profile in axial spondyloarthritis

Calprotectin (CPT) is released during inflammation, also in the context of atherosclerosis. The link between CPT and the atherosclerotic process was evaluated in several diseases. However, studies in axial spondyloarthritis (axSpA), associated with a high incidence of subclinical atherosclerosis, are scarce. Therefore, we assessed the association of CPT with subclinical atherosclerosis and metabolic risk factors in axSpA. CPT serum levels were measured by enzyme-linked immunosorbent assay in 163 axSpA patients and 63 controls. Subclinical atherosclerosis was determined in patients by carotid ultrasonography (assessing the presence/absence of carotid plaques and carotid intima-media thickness [cIMT]). Data on inflammation, disease activity, lipid profile and treatment were collected to evaluate its relationship with CPT. axSpA patients evidenced lower CPT levels than controls. CPT showed no association with plaques or cIMT in axSpA. CPT and HDL-cholesterol negatively correlated, while a positive association of CPT with the atherogenic index was disclosed. Additionally, axSpA patients with C-reactive protein values at diagnosis higher than 3 mg/L displayed higher CPT levels. Our study shows no relationship between CPT and markers of subclinical atherosclerosis in axSpA. Nevertheless, it demonstrates an association of CPT with adverse lipid profiles and inflammatory biomarkers, which could further influence on the development of atherosclerosis.

Multiple gut-liver axis abnormalities in children with obesity with and without hepatic involvement

BACKGROUND

Gut-liver axis (GLA) dysfunction appears to play a role in obesity and obesity-related hepatic complications.

OBJECTIVES

This study sought to concurrently explore several GLA components in a paediatric obese population with/without liver disease.

METHODS

Thirty-two children (mean age 11.2 years) were enrolled: nine controls with normal weight and 23 patients with obesity (OB+). Of the 23 patients OB(+), 12 had not steatosis (ST-), and 11 had steatosis (ST+) (associated [n = 8] or not [n = 3] with hypertransaminasaemia [ALT +/-]). Subjects were characterized by using auxologic, ultrasonographic and laboratory parameters. A glucose hydrogen breath test was performed to test for small intestinal bacterial overgrowth, a urinary lactulose/mannitol ratio (LMR) was obtained to assess intestinal permeability, and tests for transaminases, blood endogenous ethanol, endotoxin and faecal calprotectin were also conducted.

RESULTS

Eleven out of 23 patients OB(+) (p < 0.05) exhibited pathological (>90th percentile of the control group values) LMR, with values paralleling the grade of liver involvement (normal weight < OB[+] < OB[+]ST[+]ALT[-] < OB[+)]ST[+]ALT[+] [p < 0.05]). LMR significantly correlated with ethanolaemia (r = 0.38, p = 0.05) and endotoxaemia (r = 0.48, p = 0.015) concentrations. Increased permeability was a risk factor for the development of steatosis (p < 0.002). SIBO was present only in patients with obesity. Faecal calprotectin concentrations were within normal limits in all subjects.

CONCLUSIONS

Increased permeability, endogenous ethanol and systemic endotoxin concentrations reflect some GLA dysfunction in obesity and its hepatic complications. Pending further results to establish their potential causative roles, the modulation of the GLA appears to represent a possible target for the prevention and treatment of these conditions.

Sample Type and Storage Conditions Affect Calprotectin Measurements in Blood

BACKGROUND

Calprotectin, a complex of calcium-binding proteins, is abundant in granulocytes. Increased levels of plasma calprotectin have been found in patients with inflammatory and autoimmune diseases. However, a number of preanalytical factors may affect calprotectin measurement in blood samples.

METHODS

Twelve blood samples [4 tubes, 1 each of lithium-heparin (Li-heparin), EDTA, and serum] were drawn from each of 14 healthy individuals. To evaluate the effect of temperature and storage time in the lag time between collection and centrifugation, samples were kept for 2 h at 4 °C, 20 °C, or 37 °C, before centrifugation. Leukocyte, neutrophil, and monocyte counts were measured in EDTA samples on a Sysmex XN-10 hematology analyzer to investigate the relationship between calprotectin concentrations and the granulocyte count.

RESULTS

Calprotectin measurements in EDTA samples were not influenced by temperature or time lag between collection and analysis. Compared to EDTA plasma, significantly higher calprotectin concentrations were found in serum and Li-heparin plasma samples. Furthermore, calprotectin concentrations increased in serum and Li-heparin samples when stored at higher temperatures. There was a linear relationship between the serum calprotectin concentration and neutrophil count in EDTA whole blood.

CONCLUSIONS

EDTA is the most suitable anticoagulant for determination of calprotectin in plasma, as this sample matrix does not seem to be affected by temperature or time between sample collection and analysis. Of particular note, neutrophil activation by either clotting or centrifugation should be avoided during the preanalytical process.

The comparison of acute high-intensity interval exercise vs. continuous moderate-intensity exercise on plasma calprotectin and associated inflammatory mediators

PURPOSE

Calprotectin promotes the release of inflammatory mediators (e.g., monocyte chemoattractant protein-1 [MCP-1] and myeloperoxidase [MPO]) during the innate immune response as a mechanism to augment leukocyte chemotaxis and phagocytosis. Although plasma calprotectin is elevated with traditional continuous moderate-intensity exercise (CME) as an indicator of the inflammatory response, high-intensity interval exercise (HIIE) has been shown to attenuate systemic inflammation while providing similar improvements in cardiovascular health. Therefore, the purpose of this study was to compare plasma levels of calprotectin, MCP-1, and MPO between acute HIIE vs. CME.

METHODS

Nine healthy males (24.67±3.27yrs) were recruited to participate in HIIE and CME on a cycle ergometer. HIIE consisted of 10 repeated 60s of cycling at 90% max watts (W_max) separated by 2min of active recovery intensity of interval exercise, whereas CME consisted of 28min of cycling at 60% W_max. Blood samples were collected prior to, immediately post, and 30 and 60min into recovery following exercise.

RESULTS

Acute HIIE elicited a lower elevation in calprotectin and MPO compared to CME. An increase in MCP-1 was observed across time in both exercise protocols. Furthermore, our analyses did not reveal any significant correlation in percent change (baseline to immediately following exercise) among calprotectin, MCP1, and MPO in neither HIIE nor CME. However, a significant positive correlation was observed in the overall release of calprotectin and MPO across all four time points in both HIIE and CME. Conclusions Our findings indicate that acute HIIE may potentially diminish the systemic release of inflammatory mediators (calprotectin and MPO) compared to CME.

Ischemic colitis of the colon in streptozotocin-induced diabetic rats

This study focuses on two inflammatory diseases, viz., "diabetes mellitus (DM)" that causes serious complications such as retinopathy, nephropathy, and neuropathy, and "ischemic colitis" which is evoked by DM. Ischemic colitis originates from the reduction in mesenteric blood flow to the colon with existence of the occlusive or non-occlusive reasons. Our study objective was to provide early diagnostic approach for ischemic colitis in streptozotocin (STZ)-induced diabetic rats. Sprague-Dawley rats were divided into four groups: (i) control use of 0.1 M citrate buffer, the solvent of streptozotocin (C), (ii). induced ischemia (I), (iii) rats subjected to 60 mg/kg STZ intraperitoneally to induce type 1 diabetes (D) (48 h after STZ injection, blood glucose levels >200 mg/dl were considered as diabetic), and (iv) diabetic rats subjected to intestinal ischemia (D+I). The third diabetic group (D) was not operated. At the end of the experimental period, rats were sacrificed, C-reactive protein (CRP) and calprotectin levels were measured in the serum and colon tissue specimens. Tissue specimens were also analyzed histologically. We found that serum and colon calprotectin levels were elevated in the D+I group compared to the D and/or I group alone, but relatively calprotectin levels increased in I as compared to C group in colon tissues. CRP levels were significantly increased with ischemic colitis in diabetes, while colon CRP levels were decreased. These results provide evidence for the existence of inflammation in the STZ-induced diabetic rats with ischemic colitis. In conclusion, our measurements of serum calprotectin levels of STZ-induced diabetic rats with ischemic colitis provide a practical approach for an early diagnosis of ischemic colitis. Furthermore, these biochemical analyses correlate well with the histopathologic findings of STZ-induced diabetic rats with ischemic colitis. Future studies would be desirable to further strengthen the role of calprotectin in the early diagnosis of ischemic colitis in diabetics clinical settings.

Elevated serum tartrate-resistant acid phosphatase isoform 5a levels in metabolic syndrome

Background

Tartrate-resistant phosphatase isoform 5a is expressed in tumor-associated macrophages and is a biomarker of chronic inflammation. Herein, we correlated serum tartrate-resistant phosphatase isoform 5a levels with metabolic syndrome status and made comparisons with traditional markers of inflammation, including c-reactive protein and interleukin-6.

Methods

One hundred healthy volunteers were randomly selected, and cut-off points for metabolic syndrome related inflammatory biomarkers were determined using receiver operating characteristic curves. Linear and logistic regression models were subsequently used to correlate inflammatory markers with the risk of metabolic syndrome.

Results

Twenty-two participants met the criteria for metabolic syndrome, and serum tartrate-resistant phosphatase isoform 5a levels of >5.8 μg/L were associated with metabolic syndrome (c-statistics, 0.730; p = 0.001; 95% confidence interval, 0.618-0.842). In addition, 1 μg/L increases in tartrate-resistant phosphatase isoform 5a levels were indicative of a 1.860 fold increase in the risk of metabolic syndrome (p = 0.012).

Conclusions

Elevated serum tartrate-resistant phosphatase isoform 5a levels are associated with the risk of metabolic syndrome, with a cut-off level of 5.8 μg/L.

Reduction of calprotectin and phosphate during testosterone therapy in aging men: a randomized controlled trial

OBJECTIVES

To investigate the effect of testosterone treatment on biomarkers calprotectin, fibroblast growth factor 23 (FGF23), soluble Klotho, phosphate, calcium, parathyroid hormone, creatinine and estimated glomerular filtration rate.

DESIGN

Randomized, double-blinded, placebo-controlled study.

SETTING

Odense Androgen Study-the effect of Testim and training in hypogonadal men.

PARTICIPANTS

Men aged 60-78 years old with a low normal concentration of free of bioavailable testosterone <7.3 nmol/L and waist circumference >94 cm recruited from 2008 to 2009 (N = 48) by advertisement.

INTERVENTION

Participants were randomized to receive 5-10 g gel/50-100 mg testosterone (Testim^®, Ipsen, France) or 5-10 g gel/placebo.

RESULTS

The plasma levels of calprotectin and phosphate were significantly reduced in the group receiving testosterone therapy (gel) compared to the placebo group (p < 0.05). Testosterone treatment did not have any significant effect on plasma levels of FGF23 or soluble Klotho. The reduction in phosphate levels was inversely associated with bioavailable testosterone.

CONCLUSION

Compared to the placebo group, 6 months of testosterone therapy (gel) reduced calprotectin and phosphate levels suggesting decreased inflammation and decreased cardiovascular risk.

Total Flavonoids Extracted from Oxytropis falcata Bunge Improve Insulin Resistance through Regulation on the IKKβ/NF-κB Inflammatory Pathway

Background. Insulin resistance (IR) is the main etiology of type 2 diabetes mellitus (T2DM). It has been known that total flavonoid extracts can markedly improve the hypoglycemic symptoms caused by IR. Nevertheless, the relevant molecular mechanism remains unclarified. Aim. This study aimed to investigate the antihyperglycemic effects and mechanism of the total flavonoid extract from Oxytropis falcata Bunge. Methods. STZ-induced T2DM rats (n = 35) were divided into 5 groups: model, low-, medium-, and high-dose total flavonoids, and pioglitazone groups. Ten healthy rats were used as controls. The serum insulin and inflammatory cytokines (MCP-1, TNF-α, and IL-6) level was measured by ELISA. The concentration of IRS-1, p-IRS-1, PKB p-PKB, PI3Kp85, and p-PI3K in skeletal muscles was determined by Western blot. The mRNA level of GLUT4, IκB, and NF-κB in skeletal muscle was detected by qRT-PCR. Results. The treatment of medium- and high-dose total flavonoids significantly reduced the FPG and P2hPG and enhanced insulin level in T2DM rats (P < 0.05). When compared with controls, the serum level of MCP-1, TNF-α, IL-6, IRS-1, and p-IRS-1 was significantly increased in T2DM rats, but the level of PKB, p-PKB, PI3Kp85, and p-PI3K expression was reduced (P < 0.05). The GLUT4 and IκB mRNA expression were significantly decreased, and NF-κB mRNA level was increased (P < 0.05). The treatment of low-, medium-, or high-dose total flavonoids markedly reversed the changes above (P < 0.05). Conclusion. Our study has confirmed the therapeutic effects of total flavonoids from Oxytropis falcata Bunge on IR. The flavonoids might reduce the production of inflammatory cytokines through downregulation of NF-κB expression in inflammatory pathway and regulate the IRS-1-PI3-K-PKB/Akt insulin pathway and thereby increased the GLUT4 expression.

Calprotectin in serum and zonulin in serum and feces are elevated after introduction of a diet with lower carbohydrate content and higher fiber, fat and protein contents

Calprotectin is a marker of inflammation and zonulin is a marker of intestinal permeability. Diets with lower carbohydrate content and higher contents of fat, fiber and protein, e.g., Okinawan-based diet, are considered to reduce inflammation and intestinal permeability. The aim of the present study was to evaluate calprotectin and zonulin levels in serum and feces after intervention with an Okinawan-based Nordic diet. Thirty patients (17 women) with type 2 diabetes, mean age 57.5±8.2 years, BMI 29.9±4.1 kg/m², were served the diet during 12 weeks, and were followed for another 16 weeks. Anthropometric and metabolic parameters were registered. Fasting levels of calprotectin and zonulin in serum and feces, and hormones in plasma, were measured by Luminex or ELISA before study start and after 12 and 28 weeks. Calprotectin in serum tended to be increased (P=0.074) after 12 weeks. Zonulin in serum and feces were elevated after 12 weeks (P=0.019 vs. P<0.001), and remained elevated in serum after 28 weeks (P=0.014). In contrast to baseline, there was a correlation between calprotectin and zonulin in serum and feces after dietary intervention (P=0.025 vs. P=0.079). Energy percentage of protein in breakfast correlated with serum calprotectin (P=0.008) and tended to correlate with serum zonulin (P=0.059). Calprotectin in serum tended to be elevated, and zonulin in serum and feces are elevated after introduction of an Okinawan-based Nordic diet. These biomarkers correlate with energy percentage of protein.

Two meals with different carbohydrate, fat and protein contents render equivalent postprandial plasma levels of calprotectin, cortisol, triglycerides and zonulin

The aim was to compare postprandial plasma levels of calprotectin, cortisol, triglycerides and zonulin between a control breakfast and a moderately low-carbohydrate test breakfast, given randomly after 10-h fast. Blood samples were collected before and repeatedly after the meal. Plasma calprotectin, cortisol, triglycerides and zonulin were analyzed. The total area under the curve (tAUC) and change in AUC from baseline (dAUC) were calculated. Ratios between the test and control values were calculated to investigate equivalence. Healthy volunteers (8 men and 12 women; 46.0 ± 14.5 years) were included. tAUCs of cortisol and triglycerides did not differ between the breakfasts (p = 0.158 versus p = 0.579). Cortisol dAUCs were decreased and triglyceride dAUCs were increased after both breakfasts, with no differences between the breakfasts (p = 0.933 versus p = 0.277). Calprotectin and zonulin levels were unaffected. The meals were bioequivalent for cortisol, triglycerides and zonulin, but not for calprotectin.

Oleanolic Acid Attenuates Insulin Resistance via NF-κB to Regulate the IRS1-GLUT4 Pathway in HepG2 Cells

The aim of our study is to elucidate the mechanisms of oleanolic acid (OA) on insulin resistance (IR) in HepG2 cells. HepG2 cells were induced with FFA as the insulin resistance model and were treated with OA. Then the glucose content and the levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were analyzed. Moreover, protein expression of nuclear factor kappa B (NF-κB), insulin receptor substrate 1(IRS1), and glucose transporter 4 (GLUT4) in cells treated with OA were measured by Western blot analysis. Additionally, IRS1 protein expression exposed to OA was detected after using pyrrolidine dithiocarbamate (PDTC).Our results revealed that OA decreased the glucose content in HepG2 cells in vitro. Moreover, OA reduced the levels of TNF-α and IL-6 and upregulated IRS1 and GLUT4 protein expression. Furthermore, OA also reduced NF-κB protein expression in insulin-resistant HepG2 cells. After blocking NF-κB, the expression of IRS1 protein had no obvious changes when treated with OA. OA attenuated insulin resistance and decreased the levels of TNF-α and IL-6. Meanwhile, OA decreased NF-κB protein expression and upregulated IRS1 and GLUT4 protein expression. Therefore, regulating the IRS1-GLUT4 pathway via NF-κB was the underlying mechanism of OA on insulin resistance.

Role of Calprotectin as a Modulator of the IL27-Mediated Proinflammatory Effect on Endothelial Cells

An underlying endothelial dysfunction plays a fundamental role in the pathogenesis of cardiovascular events and is the central feature of atherosclerosis. The protein-based communication between leukocytes and inflamed endothelial cells leading to diapedesis has been largely investigated and several key players such as IL6, TNFα, or the damage associated molecular pattern molecule (DAMP) calprotectin are now well identified. However, regarding cytokine IL27, the controversial current knowledge about its inflammatory role and the involved regulatory elements requires clarification. Therefore, we examined the inflammatory impact of IL27 on primary endothelial cells and the potentially modulatory effect of calprotectin on both transcriptome and proteome levels. A qPCR-based screening demonstrated high IL27-mediated gene expression of IL7, IL15, CXCL10, and CXCL11. Calprotectin time-dependent downregulatory effects were observed on IL27-induced IL15 and CXCL10 gene expression. A mass spectrometry-based approach of IL27 ± calprotectin cell stimulation enlightened a calprotectin modulatory role in the expression of 28 proteins, mostly involved in the mechanism of leukocyte transmigration. Furthermore, we showed evidence for STAT1 involvement in this process. Our findings provide new evidence about the IL27-dependent proinflammatory signaling which may be under the control of calprotectin and highlight the need for further investigations on molecules which might have antiatherosclerotic functions.

Revisiting the adipocyte: a model for integration of cytokine signaling in the regulation of energy metabolism

Adipose tissue constitutes an extremely active endocrine organ with a network of signaling pathways enabling the organism to adapt to a wide range of different metabolic challenges, such as starvation, stress, infection, and short periods of gross energy excess. The functional pleiotropism of adipose tissue relies on its ability to synthesize and release a huge variety of hormones, cytokines, complement and growth factors, extracellular matrix proteins, and vasoactive factors, collectively termed adipokines. Obesity is associated with adipose tissue dysfunction leading to the onset of several pathologies including type 2 diabetes, dyslipidemia, nonalcoholic fatty liver, or hypertension, among others. The mechanisms underlying the development of obesity and its associated comorbidities include the hypertrophy and/or hyperplasia of adipocytes, adipose tissue inflammation, impaired extracellular matrix remodeling, and fibrosis together with an altered secretion of adipokines. Recently, the potential role of brown and beige adipose tissue in the protection against obesity has been also recognized. In contrast to white adipocytes, which store energy in the form of fat, brown and beige fat cells display energy-dissipating capacity through the promotion of triacylglycerol clearance, glucose disposal, and generation of heat for thermogenesis. Identification of the morphological and molecular changes in white, beige, and brown adipose tissue during weight gain is of utmost relevance for the identification of pharmacological targets for the treatment of obesity and its associated metabolic diseases.

Association of calprotectin with leukocyte chemotactic and inflammatory mediators following acute aerobic exercise

The objective of this study was to examine whether acute aerobic exercise-mediated calprotectin in plasma would be associated with monocyte chemotactic protein-1 (MCP-1), myeloperoxidase (MPO), and interleukin-6 (IL-6) in healthy individuals. Eleven healthy participants, aged 18 to 30 years, were recruited to perform a 30-min bout of aerobic exercise at 75% maximal oxygen uptake. Acute aerobic exercise elicited a significant elevation across time in plasma calprotectin, MCP-1, MPO, and IL-6. Body mass index (BMI) was positively correlated with calprotectin area-under-the-curve with "respect to increase" (AUCi) and IL-6 AUCi. Furthermore, calprotectin AUCi was positively correlated with IL-6 AUCi and MPO AUCi, even after controlling for BMI. Although MPO AUCi was positively correlated with IL-6 AUCi, this relationship no longer existed after controlling for BMI. These results suggest that acute aerobic exercise could mediate innate immune response associated with calprotectin and its related leukocyte chemotactic and inflammatory mediators, especially in individuals with elevated BMI.