Upregulation of oxidative stress gene markers during SARS-COV-2 viral infection

Severe viral infections, including SARS-COV-2, could trigger disruption of the balance between pro-oxidant and antioxidant mediators; the magnitude of which could reflect the severity of infection and lung injury. Using publicly available COVID-19 transcriptomic datasets, we conducted an in-silico analyses to evaluate the expression levels of 125 oxidative stress genes, including 37 pro-oxidant genes, 32 oxidative-responsive genes, and 56 antioxidant genes. Seven oxidative stress genes were found to be upregulated in whole blood and lung autopsies (MPO, S100A8, S100A9, SRXN1, GCLM, SESN2, and TXN); these genes were higher in severe versus non-severe COVID-19 leucocytes. Oxidative genes were upregulated in inflammatory cells comprising macrophages and CD8⁺ T cells isolated from bronchioalveolar fluid (BALF), and neutrophils isolated from peripheral blood. MPO, S100A8, and S100A9 were top most upregulated oxidative markers within COVID-19's lung autopsies, whole blood, leucocytes, BALF derived macrophages and circulating neutrophils. The calprotectin's, S100A8 and S100A9 were upregulated in SARS-COV-2 infected human lung epithelium. To validate our in-silico analysis, we conducted qRT-PCR to measure MPO and calprotectin's levels in blood and saliva samples. Relative to uninfected donor controls, MPO, S100A8 and S100A9 were significantly higher in blood and saliva of severe versus asymptomatic COVID-19 patients. Compared to other different viral respiratory infections, coronavirus infection showed a prominent upregulation in oxidative stress genes with MPO and calprotectin at the top of the list. In conclusion, SARS-COV-2 induce the expression of oxidative stress genes via both immune as well as lung structural cells. The observed correlation between oxidative stress genes dysregulation and COVID-19 disease severity deserve more attention. Mechanistical studies are required to confirm the correlation between oxidative stress gene dysregulation, COVID-19 severity, and the net oxidative stress balance.

[Expression and distribution of calprotectin in healthy and inflamed periodontal tissues]

OBJECTIVE

Calprotectin, the heterdimer of S100A8 and S100A9, is the major cytoplasmic protein of neutrophils, which is also expressed or induced in gingival epithelial cells, activated mononuclear macrophages and vascular endothelial cells. Calprotectin is intimately associated with the initiation and progression of periodontitis, but the in vivo expression patterns of calprotectin in healthy and inflamed periodontal tissue are not fully understood. To observe the expression, distribution and cellular localization of calprotectin in the samples of healthy periodontal tissues and experimental periodontitis tissues of Beagles and to explore their relationship with periodontal inflammation and possible effect.

METHODS

Experimental periodontitis model was established by ligation around the mandibular second molar of the Beagle dogs, while the contralateral teeth were healthy controls. Induction duration was 12 weeks, before the dogs were executed. Tissue specimens were demineralized and serial sections were made conventionally. The in vivo expression of calprotectin in the healthy and inflamed periodontal tissues were examined by immunohistochemistry. The in vitro expression of calprotectin in human primary gingival fibroblasts (GFs) and periodontal ligament (PDL) cells were detected by immunocytochemistry.

RESULTS

Immunohistochemistry analysis indicated that calprotectin was expressed in gingival epithelial cells and infiltrated neutrophils in the healthy periodontium within the gingival epithelium, S100A8/A9 was most strongly expressed in the junctional epithelium, followed by surface epithelium, and least expressed in the sulcular epithelium. The S100A8/A9 expression levels were sharply defined at the junction between the junctional epithelium and the sulcular epithelium. In periodontal inflammatory lesions, the expression level of calprotectin in sulcular epithelium and junctional epithelium was up-regulated than that in the healthy gingival epithelium. Calprotectin was inducibly expressed in fibroblast-like cells in gingival connective tissue and periodontal ligament tissue, microvascular endothelial cells (ECs) and bone marrow fibroblasts under inflammatory conditions. Additionally, the expression of calprotectin in primary human GFs and PDL cells was confirmed by immunnocytochemistry staining.

CONCLUSION

Constitutively expressed in neutrophils and gingival epithelial cells, and calprotectin might maintain the homeostasis and integrity of periodontium. Inflammation-induced expression of calprotectin in GFs, PDL cells, microvascular ECs and bone marrow fibroblasts might process anti-microbial function and promote leukocytes transmigration to defend the host against the microorganisms.

Circulating levels of tight junction proteins in multiple sclerosis: Association with inflammation and disease activity before and after disease modifying therapy

BACKGROUND

Tight junction proteins contribute to maintenance of epithelial and endothelial barriers such as the intestinal barrier and the blood brain barrier (BBB). Increased permeability of these barriers has been linked to disease activity in MS and there is currently a lack of easily accessible biomarkers predicting disease activity in MS.

AIM

To investigate whether levels of circulating tight junction proteins occludin and zonula occludens-1 (ZO-1) are associated with biomarkers of inflammation and disease activity; and to determine whether they could serve as clinical biomarkers.

METHODS

We prospectively included 72 newly diagnosed patients with relapsing remitting MS or clinically isolated syndrome with no prior disease modifying therapy (DMT) use and 50 healthy controls (HCs). Patients were followed with blood samples, 3 tesla MRI, and clinical evaluation for 12 months. Occludin, ZO-1, calprotectin and soluble urokinase-type plasminogen activator receptor (suPAR) were measured by ELISA; serum neurofilament light (NfL) and IL-6 by single-molecule array (SIMOA). The mRNA expression of IFNG, IL1R1, IL10, IL1B, ARG1 and TNF was measured by quantitative real time polymerase chain reaction (qPCR) in whole blood.

RESULTS

Plasma occludin levels were higher in MS patients compared with HCs. After 12 months on DMT, occludin levels were reduced by approximately 25% irrespective of 1st or 2nd line DMT (p<0.001). Furthermore, NfL and calprotectin levels were significantly reduced by 31% and 29%, respectively. Occludin and ZO-1 did not correlate with biomarkers of inflammation and did not predict disease activity at baseline or after 12 months.

CONCLUSIONS

Higher levels of occludin suggest an increased permeability of the BBB and/or the intestinal barrier in MS patients. The reduction of occludin after 12 months on DMTs might reflect repair of these barriers upon treatment. However, plasma levels of ZO-1 and occludin could not predict clinical or MRI disease activity as determined by regression and ROC-curve analysis. Our results do not indicate a clear clinically relevant role for circulating tight junction proteins as biomarkers of disease activity in MS and further investigations in larger cohorts are needed to clarify this issue.

Increased levels of S100A8/A9, IL-1ß and IL-18 as a novel biomarker for recurrent tonsillitis

Background

Acute tonsillitis represents one of the most frequent reasons patients seek primary medical care and otorhinolaryngology consultation. Therefore, recurrent episodes of acute tonsillitis (RAT), also called chronic tonsillitis, exhaust a substantial amount of medical and financial resources. Diagnosis of tonsillitis depends on a physical examination, which therefore does not allow for a reliable differentiation between viral and bacterial infection. However, the frequency of bacterial infections during the previous three years is currently being used as the major deciding factor in patient selection for tonsillectomy. The aim of the present study was to determine an objective biomarker to help in the identification of patients suffering from recurrent tonsillitis.

Results

By analyzing a panel of cytokines and chemokines in serum and saliva of patients with RAT compared to healthy controls, increased levels of IL-1ß (153.7 ± 48.5 pg/ml vs 23.3 ± 6.6 pg/ml, p = 0.021), IL-18 (120.2 ± 16.5 vs 50.6 ± 9.3 pg/ml, p = 0.007) and/or S100A8/A9 (996 ± 102 ng/ml vs 546 ± 86 ng/ml, p = 0.042) could be observed in patients suffering from RAT. Cut-off values of these parameters were determined and combined to a new RAT-score allowing for reliable identification of patients suffering from recurrent tonsillitis with a sensitivity of 95% and a specificity of 88%.

Conclusion

The RAT-score represents the first objective criterion as a tool for the diagnosis of recurrent tonsillitis and it also improves patient selection for tonsillectomy.

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.

Serum calprotectin as a prognostic predictor in severe traumatic brain injury

BACKGROUND

Calprotectin plays an important role during inflammation. We intended to explore the prognostic value of serum calprotectin levels in patients with severe traumatic brain injury (sTBI).

METHODS

In this prospective cohort study of 149 sTBI patients, we determined the relationship between serum calprotectin levels and 90-day overall survival plus poor outcome (Glasgow outcome scale score of 1-3) after sTBI, and analyzed its associations with Rotterdam computerized tomography (CT) scores, Glasgow coma scale (GCS) scores and two markers of inflammatory reaction including serum C-reactive protein levels and blood leucocyte count.

RESULTS

Serum calprotectin levels were significantly correlated with Rotterdam CT scores, GCS scores, serum C-reactive protein levels and blood leucocyte count. Patients with poor outcome at 90 days displayed higher serum calprotectin levels than the other remainders. Serum calprotectin appeared as an independent predictor for 90-day overall survival and poor outcome. Under receiver operating characteristic curve, serum calprotectin levels exhibited an efficient discrimination capacity for 90-day poor outcome.

CONCLUSIONS

Serum calprotectin levels are significantly correlated with inflammation, trauma severity and poor outcome at 90 days in sTBI patients, suggesting that serum calprotectin may be a biomarker for providing complementary prognostic information to identify patients at risk of poor outcome after sTBI.

In Vitro Inhibitory Effect of Recombinant Human Calprotectin on Nalm6 Leukemia Cell Line

BACKGROUND & PURPOSE

In evaluating new drugs for the treatment of various types of cancer, investigations have been made to discover a variety of anti-tumor compounds with less side effects on normal cells. Investigations have shown that the heterodimers S100A8 and S100A9 inhibit the enzyme casein kinase 2 and then prevent the activation of the E7 oncoprotein. Therefore, the aim of this study was to evaluate the effect of calprotectin as an antitumor compound on the Nalm6 (B cell precursor leukemia cell line).

MATERIALS & METHODS

Transformation of genes encoding S100A8 and S100A9 human, designed in the pQE32 plasmid, was performed by the thermal shock method into E. coli M15 bacteria. After bacterial growth in LB medium, the expression of two S100A8 and S100A9 subunits, the solubility of the protein by SDS-PAGE method was determined. Finally, the S100A8 / A9 complex was equally placed in the microtube. In the next step, the cytotoxic effects of calprotectin produced on the Nalm6 cell line were evaluated using the wst1 test. Then, the apoptosis in these cells was measured using flow cytometry methods with Annexin-V coloration.

RESULTS

In the current study, the results showed that the cytotoxic effects of Calprotectin are time and concentration- dependent. Therefore, it can reduce the tumor expression and had a beneficial effect by induced apoptosis in Nalm6 cell line.

CONCLUSION

Calprotectin has an anti-tumor effect on the Nalm6 cell line by increasing apoptosis.

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

BACKGROUND

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

The gut microbiota is associated with the small intestinal paracellular permeability and the development of the immune system in healthy children during the first two years of life

BACKGROUND

The intestinal barrier plays an important role in the defense against infections, and nutritional, endocrine, and immune functions. The gut microbiota playing an important role in development of the gastrointestinal tract can impact intestinal permeability and immunity during early life, but data concerning this problem are scarce.

METHODS

We analyzed the microbiota in fecal samples (101 samples in total) collected longitudinally over 24 months from 21 newborns to investigate whether the markers of small intestinal paracellular permeability (zonulin) and immune system development (calprotectin) are linked to the gut microbiota. The results were validated using data from an independent cohort that included the calprotectin and gut microbiota in children during the first year of life.

RESULTS

Zonulin levels tended to increase for up to 6 months after childbirth and stabilize thereafter remaining at a high level while calprotectin concentration was high after childbirth and began to decline from 6 months of life. The gut microbiota composition and the related metabolic potentials changed during the first 2 years of life and were correlated with zonulin and calprotectin levels. Faecal calprotectin correlated inversely with alpha diversity (Shannon index, r = - 0.30, FDR P (Q) = 0.039). It also correlated with seven taxa; i.a. negatively with Ruminococcaceae (r = - 0.34, Q = 0.046), and Clostridiales (r = - 0.34, Q = 0.048) and positively with Staphylococcus (r = 0.38, Q = 0.023) and Staphylococcaceae (r = 0.35, Q = 0.04), whereas zonulin correlated with 19 taxa; i.a. with Bacillales (r = - 0.52, Q = 0.0004), Clostridiales (r = 0.48, Q = 0.001) and the Ruminococcus (torques group) (r = 0.40, Q = 0.026). When time intervals were considered only changes in abundance of the Ruminococcus (torques group) were associated with changes in calprotectin (β = 2.94, SE = 0.8, Q = 0.015). The dynamics of stool calprotectin was negatively associated with changes in two MetaCyc pathways: pyruvate fermentation to butanoate (β = - 4.54, SE = 1.08, Q = 0.028) and Clostridium acetobutylicum fermentation (β = - 4.48, SE = 1.16, Q = 0.026).

CONCLUSIONS

The small intestinal paracellular permeability, immune system-related markers and gut microbiota change dynamically during the first 2 years of life. The Ruminococcus (torques group) seems to be especially involved in controlling paracellular permeability. Staphylococcus, Staphylococcaceae, Ruminococcaceae, and Clostridiales, may be potential biomarkers of the immune system. Despite observed correlations their clear causation and health consequences were not proven. Mechanistic studies are required.

Effect of zinc supplementation on relative expression of immune response genes in neonates with sepsis: A preliminary study

Background & objectives

Zinc alters gene expression mainly by binding to a site on the transcription factor. Genome-wide expression studies have shown early repression of genes related to zinc and immunity in adult patients with sepsis. The present study was conducted to evaluate the role of zinc supplementation on relative expression of immune response genes in neonatal sepsis.

Methods

In the present study, a sample of convenience of 22 neonates each was selected from the zinc supplemented and control groups using random numbers for expression of immune-related genes by zinc supplementation. These neonates with sepsis were earlier randomized into two groups: with and without zinc supplementation in addition to standard antibiotics and supportive care. Relative expression of immune response genes were analyzed for 22 neonates in each group using quantitative real-time PCR for calprotectin (S100A8/A9), tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), toll-like receptor-4 (TLR-4), cluster of differentiation 14 (CD14) and lipopolysaccharide-binding protein (LBP) genes.

Results

An increase in serum zinc levels was observed in zinc-supplemented group compared to controls. S100A8 gene showed downregulation by three-fold (P <0.001) and S100A9 gene showed upregulation by two-fold (P <0.05) in zinc group compared to controls. CD14 gene showed upregulation by one-fold in zinc-supplemented group compared to controls (P <0.05). No significant fold changes were observed with respect to TNF-α, IL-6, LBP and TLR-4 genes between the two groups.

Interpretation & conclusions

The results of our preliminary study showed that the zinc supplementation might modulates the relative expression of immune-related genes involved in sepsis pathway among neonates. However, studies with larger sample size are needed to be done to provide a better picture on the outcome by gene expression in neonatal sepsis by zinc supplementation.

Faecal Inflammatory Biomarkers and Gastrointestinal Symptoms after Bariatric Surgery: A Longitudinal Study

Background

Bariatric surgery induces various gastrointestinal (GI) modifications. We performed the first study longitudinally assessing the effect of bariatric surgery on faecal inflammatory biomarker levels and its relation with GI complaints.

Method

Faecal calprotectin, lactoferrin, and calgranulin-C levels were determined in 41 patients (34 Roux-en-Y [RYGB], 7 sleeves) before and at 6-16 weeks, 6 months, and 1 year after surgery. Changes in biomarker levels and percentage of patients above reference value were determined. Gastrointestinal symptom rating scale (GSRS) was used to assess GI complaints at corresponding time points. The postoperative relation between GSRS score and biomarker levels above reference value was investigated.

Results

After RYGB, median calprotectin levels are significantly higher (>188, 104-415 μg/g) than before surgery (40, 19-78 μg/g; p < 0.001), and over 90% of patients have levels above reference value 1 year after surgery. Median lactoferrin was 0.4 (0.2-1.6) μg/g before, and >5.9 (1.8-13.6) μg/g after surgery (p < 0.001). Median calgranulin-C levels remained far below the reference value and were 0.13 (0.05-0.24) μg/g before and <0.23 (0.06-0.33) μg/g after surgery. Similar results were found after sleeve gastrectomy. No difference was seen in GSRS score for patients with calprotectin and lactoferrin levels above reference values.

Conclusion

Faecal inflammatory biomarkers calprotectin and lactoferrin, but not calgranulin-C, rise above reference values shortly after bariatric surgery and remain elevated in the majority of patients. The discrepancy between calprotectin and calgranulin-C levels suggests no GI inflammation. Furthermore, patients after RYGB with biomarkers above the population reference value do not seem to have more GI complaints.

Short-chain fatty acids and intestinal inflammation in multiple sclerosis: modulation of female susceptibility by microbial products?

BACKGROUND

Multiple Sclerosis (MS) is an autoimmune-mediated disease of the central nervous system. Experimental data suggest a role of intestinal microbiota and microbial products such as short-chain fatty acids (SCFAs) in the pathogenesis of MS. A recent clinical study reported beneficial effects (mediated by immunomodulatory mechanisms) after oral administration of the SCFA propionate in MS patients. Based on available evidence, we investigated whether SCFAs and the fecal inflammation marker calprotectin are altered in MS.

METHODS

76 subjects (41 patients with relapsing-remitting MS and 35 age-matched controls) were investigated in this case-control study. All subjects underwent clinical assessment with established clinical scales and provided fecal samples for a quantitative analysis of fecal SCFA and fecal calprotectin concentrations. Fecal markers were compared between MS patients and controls, and were analyzed for an association with demographic as well as clinical parameters.

RESULTS

Median fecal calprotectin concentrations were within normal range in both groups without any group-specific differences. Fecal SCFA concentrations showed a non-significant reduction in MS patients compared to healthy subjects. Female subjects showed significantly reduced SCFA concentrations compared to male subjects.

CONCLUSIONS

In our cohort of MS patients, we found no evidence of an active intestinal inflammation. Yet, the vast majority of the investigated MS patients was under immunotherapy which might have affected the outcome measures. The sex-associated difference in fecal SCFA concentrations might at least partially explain female predominance in MS. Large-scale longitudinal studies including drug-naïve MS patients are required to determine the role of SCFAs in MS and to distinguish between disease-immanent effects and those caused by the therapeutic regime.

Urinary calprotectin, NGAL, and KIM-1 in the differentiation of primarily inflammatory vs. non-inflammatory stable chronic kidney diseases

Introduction

It has been demonstrated that urinary neutrophil gelatinase-associated lipocalin (NGAL) and calprotectin are helpful biomarkers in the differentiation of intrinsic and prerenal acute kidney injury.

Objective

The present cross-sectional study investigates, whether urinary biomarkers are able to differentiate primarily inflammatory from non-inflammatory entities in chronic kidney disease (CKD).

Methods

Urinary calprotectin, NGAL, and kidney injury molecule-1 (KIM-1) concentrations were assessed in a study population of 143 patients with stable CKD and 29 healthy controls. Stable renal function was defined as an eGFR fluctuation ≤5 ml/min/1.73 m² in the past 12 months. Pyuria, metastatic carcinoma, and renal transplantation were regarded as exclusion criteria. Diabetic nephropathy, hypertensive nephropathy, and polycystic kidney disease were categorized as ‘primarily non-inflammatory renal diseases’ (NIRD), whereas glomerulonephritis and vasculitis were regarded as ‘primarily inflammatory renal diseases’ (IRD).

Results

Urinary calprotectin and NGAL concentrations significantly differed between CKD and healthy controls (p < 0.05 each), whereas KIM-1 concentrations did not (p = 0.84). The three biomarkers did neither show significant differences in-between the individual entities, nor the two categories of IRD vs. NIRD (calprotectin 155.7 vs. 96.99 ng/ml; NGAL 14 896 vs. 11 977 pg/ml; KIM-1 1388 vs. 1009 pg/ml; p > 0.05 each). Albumin exceeds the diagnostic power of the investigated biomarkers by far.

Conclusions

The urinary biomarkers calprotectin, NGAL, and KIM-1 have no diagnostic value in the differentiation of primarily inflammatory vs. non-inflammatory etiologies of CKD.

Roxithromycin attenuates inflammation via modulation of RAGE-influenced calprotectin expression in a neutrophilic asthma model

Background

Roxithromycin (RXM), a macrolide antibiotic, exhibits anti-asthmatic effects, but its specific mechanism of action remains elusive. We evaluated the effects of RXM on airway inflammation, the expression of calprotectin, and the activity of the receptor of advanced glycation end products (RAGE) to determine whether RXM alleviates inflammation by regulating RAGE activation, and thereby calprotectin expression, in neutrophilic asthma.

Methods

Male Brown Norway rats were sensitized with ovalbumin (OVA) and Freund’s complete adjuvant (FCA) mixture, followed by OVA challenge to induce neutrophilic asthma. RXM (30 mg/kg) or FPS-ZM1 (RAGE inhibitor, 1.5 mg/kg) was administered 30 min prior to each challenge. The infiltration of airway inflammatory cells and cytokines, as well as the expression of calprotectin and RAGE, was assessed.

Results

The expression of airway inflammatory cells and cytokines was found to be significantly elevated in OVA + FCA-induced rats. Increased expression of both calprotectin and RAGE was also detected in OVA + FCA-induced asthma [bronchoalveolar lavage fluid (BALF) calprotectin: 15.07±1.79 vs. 3.86±0.69 ng/mL; serum calprotectin: 20.47±1.64 vs. 9.29±1.31 ng/mL; lung tissue homogenates calprotectin: 28.82±1.01 vs. 12.02±1.38 ng/mg; BALF RAGE: 762.93±36.47 vs. 294.25±45.92 ng/mL; serum RAGE: 906.43±58.95 vs. 505.60±30.16 ng/mL; lung tissue homogenates RAGE: 1,585.24±177.59 vs. 461.53±63.40 ng/mg; all P<0.001]. However, all of these changes were interrupted by RXM and FPS-ZM1.

Conclusions

RXM exerted similar effects as the RAGE inhibitor FPS-ZM1 in terms of reducing airway inflammation and downregulating the expression of calprotectin and RAGE in a neutrophilic asthma model. Our findings provide novel insights into the mechanisms underlying the effect of RXM pretreatment on neutrophilic asthma. Furthermore, FPS-ZM1 may be useful as an intervention specific to the neutrophilic asthma phenotype.

Serum calprotectin as a novel biomarker for severity of COVID-19 disease

Background

Some biomarkers have been reported to be related to the prognosis of the coronavirus disease 2019 (COVID-19). There are sparse data regarding the prognostic value of serum calprotectin in COVID-19 patients.

Aims

This study aimed to investigate the relationship between serum calprotectin level and clinical severity of COVID-19 disease in hospitalized patients.

Methods

This retrospective cross-sectional cohort study included 80 consecutive hospitalized patients with confirmed diagnosis of COVID-19. The study population was divided into two groups as patients hospitalized in the intensive care unit (ICU) and patients hospitalized but not in the ICU. The serum calprotectin levels, other laboratory, and clinical parameters were compared between groups.

Results

The mean age of the patients was 66.5 ± 15.7 years. Of the patients, 42 were in the ICU and 38 were not. Serum calprotectin level and acute-phase reactants such as C-reactive protein, procalcitonin, ferritin, fibrinogen, and white blood cell were significantly higher in ICU patients than in non-ICU patients. ROC curve analysis identified that serum calprotectin level was a predictor for ICU requirement with an area under the curve of 0.641 (p = 0.031). Logistic regression analysis revealed that serum calprotectin was a significant determinant for whether or not patient required the ICU.

Conclusions

These findings demonstrate that serum calprotectin level seems to be a useful biomarker that can predict the severity of COVID-19 disease. Serum calprotectin is a significant predictor of ICU requirement in patients with COVID-19.

Effect of supplemental prebiotics, probiotics and bioactive proteins on the microbiome composition and fecal calprotectin in C57BL6/j mice

The composition and metabolic activity of the microbiome affect many aspects of health, and there is current interest in dietary constituents that may affect this system. The purpose of this study was to evaluate the effects of a mix of probiotics, a mix of prebiotics and a bioactive protein fraction on the microbiome, when fed to mice alone and in combination at physiologically relevant doses. Mice were fed the total western diet (TWD) supplemented with prebiotics, probiotics, and bioactive proteins individually and in combination for four weeks. Subsequently, effects on the composition of the gut microbiome, gut short-chain fatty acids (SCFAs) concentration, and gut inflammation were measured. Ruminococcus gnavus was increased in mice gut microbiome after feeding prebiotics. Bifidobacterium longum was increased after feeding probiotics. The treatments significantly affected beta-diversity with minor treatment effects on cecal or fecal SCFAs levels, and the treatments did not affect gut inflammation as measured by fecal calprotectin.

Blood Biomarkers for Monitoring and Prognosis of Large Vessel Vasculitides

PURPOSE OF REVIEW

Large vessel vasculitides (LVVs) are inflammatory conditions of the wall of large-sized arteries, mainly represented by giant cell arteritis (GCA) and Takayasu arteritis (TA). The inflammatory process within the vessel wall can lead to serious consequences such as development of aneurysms, strokes and blindness; therefore, early diagnosis and follow-up of LVV are fundamental. However, the arterial wall is poorly accessible and blood biomarkers are intended to help physicians not only in disease diagnosis but also in monitoring and defining the prognosis of these conditions, thus assisting therapeutic decisions and favouring personalised management. The field is the object of intense research as the identification of reliable biomarkers is likely to shed light on the mechanisms of disease progression and arterial remodelling. In this review, we will discuss the role of blood biomarkers in LVVs in the light of the latest evidence.

RECENT FINDINGS

In clinical practice, the most widely performed laboratory investigations are the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). However, these indices may be within normal limits during disease relapse and they are not reliable in patients receiving interleukin-6 (IL-6) receptor inhibitors. New biomarkers struggle to gain traction in clinical practice and no molecule with good accuracy has been identified to date. IL-6, a pro-inflammatory cytokine that drives CRP synthesis and increases the ESR, is one of the most promising biomarkers in the field. IL-6 analysis is increasingly performed, and serum levels are more sensitive than ESR for active GCA and might reflect persistent inflammation with high risk of relapse in patients on IL-6 receptor inhibitors. A future with biomarkers that reflect different disease features is an important aspiration. Accordingly, intense effort is being made to identify IL-6-independent inflammatory biomarkers, such as S100 proteins, pentraxin-3 and osteopontin. Moreover, metalloproteinases such as MMP2/9 and angiogenic modulators such as VEGF, YLK-40 and angiopoietins are being studied as markers of arterial remodelling. Lastly, biomarkers indicating organ damage may guide prognostic stratification as well as emergency therapeutic decisions: the most promising biomarkers so far identified are NT-proBNP, which reflects myocardial strain; pentraxin-3, which has been associated with recent optic nerve ischemia; and endothelin-1, which is associated with ischaemic complications. Currently, the use of these molecules in clinical practice is limited because of their restricted availability, lack of sufficient studies supporting their validity and associated costs. Further evidence is required to better interpret their biological and clinical value.

Association of calprotectin with other inflammatory parameters in the prediction of mortality for ischemic stroke

BACKGROUND

Inflammatory response plays an important role in many processes related to acute ischemic stroke (AIS). Calprotectin (S100A8/S100A9), released by monocytes and neutrophils, is a key protein in the regulation of inflammation and thrombosis. The purpose of this study is to evaluate the association of circulating calprotectin with other inflammatory biomarkers and AIS prognosis, as well as the calprotectin content in stroke thrombi.

METHODS

Among the 748 patients treated at a comprehensive stroke center between 2015 and 2017, 413 patients with confirmed acute ischemic injury were prospectively evaluated. Patients with systemic inflammation or infection at onset were excluded. Plasma calprotectin was measured by ELISA in blood samples of AIS patients within the first 24 h. Univariate and multivariate logistic regression models were performed to evaluate its association with mortality and functional independence (FI) at 3 months (defined as modified Rankin Scale < 3) and hemorrhagic transformation (HT) after ischemic stroke. Further, S100A9 was localized by immunostaining in stroke thrombi (n = 44).

RESULTS

Higher calprotectin levels were associated with 3-month mortality, HT, and lower 3-month FI. After adjusting for potential confounders, plasma calprotectin remained associated with 3-month mortality [OR (95% CI) 2.31 (1.13-4.73)]. Patients with calprotectin ≥ 2.26 μg/mL were 4 times more likely to die [OR 4.34 (1.95-9.67)]. Addition of calprotectin to clinical variables led to significant improvement in the discrimination capacity of the model [0.91 (0.87-0.95) vs 0.89 (0.85-0.93); p < 0.05]. A multimarker approach demonstrated that patients with increased calprotectin, CRP, and NLR had the poorest outcome with a mortality rate of 42.3% during follow-up. S100A9 protein, as part of the heterodimer calprotectin, was present in all thrombi retrieved from AIS patients. Mean S100A9 content was 3.5% and tended to be higher in patients who died (p = 0.09). Moreover, it positively correlated with platelets (Pearson r 0.46, p < 0.002), leukocytes (0.45, p < 0.01), and neutrophil elastase (0.70, p < 0.001) thrombus content.

CONCLUSIONS

Plasma calprotectin is an independent predictor of 3-month mortality and provides complementary prognostic information to identify patients with poor outcome after AIS. The presence of S100A9 in stroke thrombi suggests a possible inflammatory mechanism in clot formation, and further studies are needed to determine its influence in resistance to reperfusion.

Self-monitoring with home based fecal calprotectin is associated with increased medical treatment. A randomized controlled trial on patients with inflammatory bowel disease

OBJECTIVES

Self-monitoring of inflammatory bowel disease (IBD) with the assistant of telemedicine and home-based fecal calprotectin (FC) tests is evolving in the management of IBD. We performed a randomized controlled trial to investigate the compliance and effects of the model IBD-Home in patients with IBD.

MATERIALS AND METHODS

Patients were randomized to IBD-Home + standard care (n = 84) or standard care alone (n = 74). Intervention with IBD-Home included IBDoc^® FC test kits and a digital application used for answering symptom questionnaires (Abbvie/Telia). They were instructed to use these on demand during a 12-month period. Data was collected retrospectively from medical records. Patients who completed the intervention were phoned and asked to answer a survey about the experience of IBD-Home.

RESULTS

The compliance to IBD-Home was low (29%). Women were more compliant compared with men (43% vs 17%, p < .001). A significantly higher proportion of patients in the IBD-Home group increased their medical treatment during the study period in comparison to control subjects (33% vs 15% p = .007) and there was an association between an increase in treatment and compliance to IBD home (multivariate odds ratio 3.22; 95^th confidence interval 1.04 - 9.95). Overall patients reported a positive experience with slight technical difficulties.

CONCLUSION

Self-monitoring with home based fecal calprotectin and a digital application was found feasible and appreciated by compliers. Compliance to the IBD-Home model was more common in women and associated with an increased treatment for IBD.

Iron in immune cell function and host defense

The control over iron availability is crucial under homeostatic conditions and even more in the case of an infection. This results from diverse properties of iron: first, iron is an important trace element for the host as well as for the pathogen for various cellular and metabolic processes, second, free iron catalyzes Fenton reaction and is therefore producing reactive oxygen species as a part of the host defense machinery, third, iron exhibits important effects on immune cell function and differentiation and fourth almost every immune activation in turn impacts on iron metabolism and spatio-temporal iron distribution. The central importance of iron in the host and microbe interplay and thus for the course of infections led to diverse strategies to restrict iron for invading pathogens. In this review, we focus on how iron restriction to the pathogen is a powerful innate immune defense mechanism of the host called "nutritional immunity". Important proteins in the iron-host-pathogen interplay will be discussed as well as the influence of iron on the efficacy of innate and adaptive immunity. Recently described processes like ferritinophagy and ferroptosis are further covered in respect to their impact on inflammation and infection control and how they impact on our understanding of the interaction of host and pathogen.

Peri-implant treatment reduces the salivary levels of Colony stimulator factor-1 and S100A8/A9

This study evaluated the impact of peri-implant treatment in the salivary levels of Colony stimulator factor -1 (CSF-1), S100A8/A9 and S100A12 in patients having mucositis or peri-implantitis. As a secondary aim, we analysed the correlation between the salivary and peri-implant crevicular fluid (PICF) levels. Forty-seven patient, 27 having mucositis (mean age 63.11 ± 7.78) and 20 having peri-implantitis (61.25 ± 7.01) participated in the study. Clinical parameters, probing pocket depth, clinical attachment level, % of plaque and bleeding on probing were evaluated. Unstimulated whole saliva was collected from all patients, while PICF was collected only from a patient's subgroup (n = 20). Samples were collected before and 3 months after peri-implant treatment. Enzyme-linked immunosorbent assays determined levels of CSF-1, S100A8/A9 and S100A12. Clinical parameters improved and salivary levels of CSF-1 and S100A8/A9, but not S100A12, reduced significantly after treatment in both groups. No significant correlation was found in the salivary and PICF levels of the same molecule. In conclusion, the treatment of peri-implant disease significantly improved the clinical parameters and reduced the salivary levels of CSF-1 and S100A8/A9. The salivary expressions of CSF-1, S100A8/A9 and S100A12 did not correlate with their own expression in PICF.

Serum Calprotectin Is a Potential Marker in Patients with Asthma

BACKGROUND

Calprotectin is the major cytosolic protein in neutrophil granulocytes. Although asthma is known to cause eosinophilic inflammation, some patients with asthma have non-eosinophilic inflammation, which is characterized by local neutrophilic inflammation. The aim of this study was to assess calprotectin expression levels in a mouse model of asthma, and to observe the relationship of serum calprotectin level and clinical variables in patients with asthma.

METHODS

Mice were sensitized and challenged with 10 μg and 20 μg of Aspergillus fumigatus, respectively; mice treated with saline were used as a control. The levels of calprotectin were determined using enzyme-linked immunosorbent assay, immunoblotting, and immunohistochemical analysis. The serum levels of calprotectin were also assessed in patients with asthma. The relationship between calprotectin and clinicopathological characteristics was determined.

RESULTS

Calprotectin, S100A8, and S100A9 expression was elevated in the mouse lungs, calprotectin levels were higher in the serum of patients with asthma (n = 33) compared with those of healthy individuals (n = 28). Calprotectin levels correlated with forced expiratory volume in one second/forced vital capacity (r = -0.215, P = 0.043), smoke amount (r = 0.413, P = 0.017), body mass index (r = -0.445, P = 0.000), and blood neutrophil percentage (r = 0.300, P = 0.004) in patients with asthma.

CONCLUSION

Our data suggest that calprotectin could potentially be used as a biomarker for asthma.

Neutrophil extracellular traps and thrombosis in COVID-19

Studies of patients with COVID-19 have demonstrated markedly dysregulated coagulation and a high risk of morbid arterial and venous thrombotic events. Elevated levels of blood neutrophils and neutrophil extracellular traps (NETs) have recently been described in patients with COVID-19. However, their potential role in COVID-19-associated thrombosis remains incompletely understood. In order to elucidate the potential role of hyperactive neutrophils and NET release in COVID-19-associated thrombosis, we conducted a case–control study of patients hospitalized with COVID-19 who developed thrombosis, as compared with gender- and age-matched COVID-19 patients without clinical thrombosis. We found that remnants of NETs (cell-free DNA, myeloperoxidase-DNA complexes, and citrullinated histone H3) and neutrophil-derived S100A8/A9 (calprotectin) in patient sera were associated with higher risk of morbid thrombotic events in spite of prophylactic anticoagulation. These observations underscore the need for urgent investigation into the potential relationship between NETs and unrelenting thrombosis in COVID-19, as well as novel approaches for thrombosis prevention.