Heparin-binding protein (HBP/CAP37): a missing link in neutrophil-evoked alteration of vascular permeability

The performance of a combination of heparin-binding protein with other biomarkers for sepsis diagnosis: an observational cohort study

BACKGROUND

HBP, a novel biomarker released from neutrophils, may induce inflammatory responses and exacerbate vascular permeability, representing the pathophysiological characteristics of sepsis and septic shock. However, it remains uncertain whether the combination of HBP with other biomarkers yields enhanced diagnostic capacity for sepsis. We hypothesized that measurements included IL-6·IL-8·HBP, IL-6·IL-8·HBP/ALB and HBP/ALB which based on HBP will improve its diagnostic efficacy and even better than the traditional infection biomarkers.

METHODS

Between July 2021 and June 2022, we carried out a comprehensive, multi-center, observational cohort study spanning six leading tertiary hospitals located in Heilongjiang Province, China. Patients were stratified into three categories based on the severity of infection: non-sepsis, sepsis, and septic shock. We collected clinical and laboratory data, along with infection and inflammation biomarkers, for analysis.

RESULTS

A total of 195 patients were enrolled. Among the three groups, patients with septic shock (n = 75, 38.5%) had significantly higher baseline levels of HBP, WBC, Lac, CRP, PCT, IL-6, IL-8, and IL-10 compared to non-sepsis patients (n = 43, 22.0%) and sepsis patients (n = 77, 39.5%), with statistically significant differences (p < 0.05) observed for all parameters. When compared to SOFA score and traditional markers of CRP, PCT, IL-6 and IL-8, the combined indexes of IL-6·IL-8·HBP and IL-6·IL-8·HBP/ALB demonstrated significantly improved diagnostic performance for sepsis and septic shock (AUC 0.911 and 0.902 respectively, p < 0.001).

CONCLUSIONS

The combined measurements of IL-6·IL-8·HBP and IL-6·IL-8·HBP/ALB can augment the diagnostic capacity of HBP for sepsis, and offer reliable early supplementary indicators to traditional biomarkers for assessing disease severity in patients with infection.

Protective effects of Ruscus extract in combination with ascorbic acid and hesperidine methylchalcone on increased leukocyte-endothelial interaction and macromolecular permeability induced by ischemia reperfusion injury

BACKGROUND

Despite the well-recognized effectiveness of Ruscus aculetus extract combined or not with ascorbic acid (AA) and hesperidine methyl chalcone (HMC) on ischemia reperfusion (I/R) injury protection, little is known about the contribution of each constituent for this effect.

OBJECTIVE

To investigate the effects of AA and HMC combined or not with Ruscus extract on increased macromolecular permeability and leukocyte-endothelium interaction induced by I/R injury.

METHODS

Hamsters were treated daily during two weeks with filtered water (placebo), AA (33, 100 and 300 mg/kg/day) and HMC (50, 150 and 450 mg/kg/day) combined or not with Ruscus extract (50, 150 and 450 mg/kg/day). On the day of experiment, the cheek pouch microcirculation underwent 30 min of ischemia, and the number of rolling and adherent leukocytes and leaky sites were evaluated before ischemia and during 45 min of reperfusion.

RESULTS

Ruscus extract combined with AA and HMC (Ruscus extract mixture) significantly prevented post-ischemic increase in leukocyte rolling and adhesion and macromolecular permeability compared to placebo and these effects were more prominent than AA and HMC alone on leukocyte adhesion and macromolecular leakage.

CONCLUSION

Ruscus extract mixture were more effective than its isolated constituents in protect the hamster cheek pouch microcirculation against I/R injury.

Diagnostic, monitoring, and prognostic value of combined detection of cerebrospinal fluid heparin-binding protein, interleukin-6, interleukin-10, and procalcitonin for post-neurosurgical intracranial infection

OBJECTIVE

Intracranial infection is a common complication after neurosurgery and can increase the length of hospital stay, affect patient prognosis, and increase mortality. We aimed to investigate the value of the combined detection of cerebrospinal fluid (CSF) heparin-binding protein (HBP), interleukin-6 (IL-6), interleukin-10 (IL-10), and procalcitonin (PCT) for post-neurosurgical intracranial infection.

METHODS

This study assessed the diagnostic values of CSF HBP, IL-6, IL-10, PCT levels, and combined assays for post-neurosurgical intracranial infection with the area under the receiver operating characteristic (ROC) curve by retrospectively analysing biomarkers of post-neurosurgical patients.

RESULTS

The CSF HBP, IL-6, IL-10, and PCT levels were significantly higher in the infected group than the uninfected group and the control group (P < 0.001). The indicators in the groups with severe intracranial infections were significantly higher than those in the groups with mild intracranial infections (P < 0.001), and the groups with poor prognoses had significantly higher indexes than the groups with good prognoses. According to the ROC curve display, the AUC values of CSF HBP, IL-6, IL-10, and PCT were 0.977 (95 % CI 0.952-1.000), 0.973 (95 % CI 0.949-0.998), 0.884 (95 % CI 0.823-0.946), and 0.819 (95 % CI 0.733-0.904), respectively. The AUC of the combined test was 0.996 (95 % CI 0.989-1.000), which was higher than those of the four indicators alone.

CONCLUSION

The combined detection can be an important indicator for the diagnosis and disease monitoring of post-neurosurgical intracranial infection.

Diagnostic and prognostic value of heparin-binding protein in sepsis: A systematic review and meta-analysis

BACKGROUND

Sepsis remains a leading cause of death worldwide. In this context, heparin-binding protein (HBP) has emerged as a possible biomarker, drawing significant attention for its diagnostic and prognostic usefulness in septic patients. Despite this advancement, the literature yields conflicting results. This study is intended to critically evaluate the diagnostic and prognostic value of HBP in critically ill septic patients.

METHODS

We searched multiple databases, including PubMed, SCOPUS, Web of Science, and EBSCO, to identify relevant studies on April 27, 2023. We included studies investigating sepsis or its severe outcomes that reported HBP levels and the required data to create 2 × 2 tables. We used R version 4.2.2 and R Studio to analyze the pooled diagnostic accuracy outcomes. The diagmeta package was utilized to calculate the optimum cutoff value.

RESULTS

In our meta-analysis, we incorporated 28 studies including 5508 patients. The analysis revealed that HBP has a sensitivity of 0.71 (95% CI: 0.60; 0.79) and a specificity of 0.68 (95% CI: 0.51; 0.81) in diagnosing sepsis, respectively. HBP demonstrated moderate prognostic accuracy for mortality at a cutoff value of 161.415 ng/mL, with a sensitivity and specificity of 72%, and for severe sepsis outcomes at a cutoff value of 58.907 ng/mL, with a sensitivity and specificity of 71%.

CONCLUSION

Our findings indicate a relatively moderate diagnostic and prognostic accuracy of HBP for sepsis. Future studies are required to verify the accuracy of HBP as a biomarker for sepsis.

Heparin-Binding Protein Promotes Acute Lung Injury in Sepsis Mice by Blocking the Aryl Hydrocarbon Receptor Signaling Pathway

Purpose

This study aimed to explore the therapeutic effect and potential mechanism of heparin-binding protein (HBP) reduction on sepsis-related acute lung injury.

Methods

We utilized a murine model of sepsis-induced by intraperitoneal injection of lipopolysaccharides (LPS) in C57BL/6J mice divided into four groups: Control, LPS, Anti-HBP, and ceftriaxone (CEF). Following sepsis induction, Anti-HBP or CEF treatments were administered, and survival rates were monitored for 48 h. We then used reverse-transcription quantitative PCR to analyze the expression levels of HBP in lung tissues, immunohistochemistry for protein localization, and Western blotting for protein quantification. Pulmonary inflammation was assessed using enzyme-linked immunosorbent assays of proinflammatory cytokines (tumor necrosis factor-α, interleukin [IL]-1β, IL-6, and interferon-γ). The activation state of the aryl hydrocarbon receptor (AhR) signaling pathway was determined via Western blotting, evaluating both cytoplasmic and nuclear localization of AhR and the expression of cytochrome P450 1A1 protein by its target gene.

Results

Anti-HBP specifically reduced HBP levels. The survival rate of mice in the Anti-HBP and CEF groups was much higher than that in the LPS group. The severity of lung injury and pulmonary inflammatory response in the Anti-HBP and CEF groups was significantly lower than that in the LPS group. AhR signaling pathway activation was observed in the Anti-HBP and CEF groups. Additionally, there was no significant difference in the above indices between the Anti-HBP and CEF groups.

Conclusion

HBP downregulation in lung tissues significantly improved LPS-induced lung injury and the pulmonary inflammatory response, thereby prolonging the survival of sepsis mice, suggesting activation of the AhR signaling pathway. Moreover, the effect of lowering the HBP level was equivalent to that of the classical antibiotic CEF.

Trial Registration

Not applicable.

Hepcidin, in contrast to heparin binding protein, does not portend acute kidney injury in patients with community acquired septic shock

BACKGROUND

Acute kidney injury (AKI) is a common and severe complication in patients treated at an Intensive Care Unit (ICU). The pathogenesis of AKI has been reported to involve hypoperfusion, diminished oxygenation, systemic inflammation, and damage by increased intracellular iron concentration. Hepcidin, a regulator of iron metabolism, has been shown to be associated with sepsis and septic shock, conditions that can result in AKI. Heparin binding protein (HBP) has been reported to be associated with sepsis and AKI. The aim of the present study was to compare serum hepcidin and heparin binding protein (HBP) levels in relation to AKI in patients admitted to the ICU.

METHODS

One hundred and forty patients with community acquired illness admitted to the ICU within 24 hours after first arrival to the hospital were included in the study. Eighty five of these patients were diagnosed with sepsis and 55 with other severe non-septic conditions. Logistic and linear regression models were created to evaluate possible correlations between circulating hepcidin and heparin-binding protein (HBP), stage 2-3 AKI, peak serum creatinine levels, and the need for renal replacement therapy (RRT).

RESULTS

During the 7-day study period, 52% of the 85 sepsis and 33% of the 55 non-sepsis patients had been diagnosed with AKI stage 2-3 already at inclusion. The need for RRT was 20% and 15%, respectively, in the groups. Hepcidin levels at admission were significantly higher in the sepsis group compared to the non-sepsis group but these levels did not significantly correlate to the development of stage 2-3 AKI in the sepsis group (p = 0.189) nor in the non-sepsis group (p = 0.910). No significant correlation between hepcidin and peak creatinine levels, nor with the need for RRT was observed. Stage 2-3 AKI correlated, as expected, significantly with HBP levels at admission in both groups (Odds Ratio 1.008 (CI 1.003-1.014, p = 0.005), the need for RRT, as well as with peak creatinine in septic patients.

CONCLUSION

Initial serum hepcidin, and HBP levels in patients admitted to the ICU are biomarkers for septic shock but in contrast to HBP, hepcidin does not portend progression of disease into AKI or a later need for RRT. Since hepcidin is a key regulator of iron metabolism our present data do not support a decisive role of initial iron levels in the progression of septic shock into AKI.

The effect of heparins on plasma concentration of heparin-binding protein: a pilot study

Background

Neutrophil-derived heparin-binding protein (HBP) plays a role in the pathophysiology of impaired endothelial dysfunction during inflammation. HBP has been suggested as a predictor of organ dysfunction and disease progression in sepsis. We investigated the effects of heparins on plasma concentrations of HBP in patients undergoing surgery.

Methods

We studied three groups of patients receiving heparins during or after surgery. The vascular surgery group received 3000-7500 U, whereas the cardiac surgery group received 27 500-40 000 U. After major general surgery, the third group received 5000 U of low-molecular-weight heparin (LMWH) subcutaneously. Serial plasma HBP concentrations were measured after these treatments with two different methods: Axis-Shield ELISA and Joinstar FIC-Q100. In addition, plasma myeloperoxidase and syndecan-1 were measured in the cardiac surgery group.

Results

During vascular surgery, heparin induced a six-fold increase in HBP within 2 min, from 3.6 (2.4-5.4) to 21.4 (9.0-35.4) ng ml-1 (P<0.001). During cardiac surgery, the higher dose of heparin elevated HBP concentrations from 5.3 (2.7-6.1) to 48.7 (38.4-70.1) ng ml-1 (P<0.0001) within 3 min. Patients receiving LMWH showed an increase from a baseline of 5.7 (3.7-12.1) ng ml-1 to a peak HBP concentration of 14.8 (9.5-18.1) ng ml-1 (P<0.0001) after 3 h. Plasma concentrations of myeloperoxidase, but not syndecan-1, also responded with a rapid increase after heparin. There was a strong correlation between the two methods for HBP analysis (r=0.94).

Conclusions

Plasma concentrations of HBP increased rapidly and dose-dependently after heparin administration. Subcutaneous administration of LMWH increases plasma HBP, but to a lesser degree.

Clinical trial registration

ClinicalTrials.gov identifier: NCT04146493.

Heparin-binding protein as a predictor of mortality in patients with diabetes mellitus and community-acquired pneumonia in intensive care unit : a propensity score matched study

BACKGROUND

Patients with diabetes mellitus (DM) are vulnerable to community-acquired pneumonia (CAP), which have a high mortality rate. We aimed to investigate the value of heparin-binding protein (HBP) as a prognostic marker of mortality in patients with DM and CAP.

METHODS

This retrospective study included CAP patients who were tested for HBP at intensive care unit (ICU) admission from January 2019 to April 2020. Patients were allocated to the DM or non-DM group and paired with propensity score matching. Baseline characteristics and clinical outcomes up to 90 days were evaluated. The primary outcome was the 10-day mortality. Receiver operating characteristic (ROC) curves, Kaplan-Meier analysis, and Cox regression were used for statistical analysis.

RESULTS

Among 152 enrolled patients, 60 pairs were successfully matched. There was no significant difference in 10-day mortality, while more patients in the DM group died within 28 d (P=0.024) and 90 d (P=0.008). In the DM group, HBP levels at ICU admission were higher in 10-day non-survivors than in 10-day survivors (median 182.21 [IQR: 55.43-300] ng/ml vs. median 66.40 [IQR: 34.13-107.85] ng/mL, P=0.019), and HBP levels could predict the 10-day mortality with an area under the ROC curve of 0.747. The cut-off value, sensitivity, and specificity were 160.6 ng/mL, 66.7%, and 90.2%, respectively. Multivariate Cox regression analysis indicated that HBP was an independent prognostic factor for 10-day (HR 7.196, 95%CI: 1.596-32.455, P=0.01), 28-day (HR 4.381, 95%CI: 1.449-13.245, P=0.009), and 90-day mortality (HR 4.581, 95%CI: 1.637-12.819, P=0.004) in patients with DM.

CONCLUSION

Plasma HBP at ICU admission was associated with the 10-day, 28-day, and 90-day mortality, and might be a prognostic factor in patients with DM and CAP.

Diagnostic value of plasma heparin-binding protein and the heparin-binding protein-to-albumin ratio in patients with community-acquired Pneumonia: a retrospective study

BACKGROUND

Patients presenting to the emergency department with community-acquired pneumonia (CAP) are characterized by advanced age, comorbidities, critical illness and less-than-typical symptoms, posing a diagnostic challenge. Plasma heparin-binding protein (HBP) and the heparin-binding protein-to-albumin ratio (HBP/Alb) have not been adequately studied in the early diagnosis of CAP. This study assessed the diagnostic value of plasma HBP, HBP/Alb, and conventional inflammatory markers in emergency department patients with CAP.

METHODS

We enrolled 103 patients with CAP, retrospectively analyzed the patients' clinical data, and divided the CAP patients into antibiotic (n = 79) and non-antibiotic (n = 24) groups based on whether antibiotics were administered prior to blood sampling and laboratory tests. The control group was comprised of 52 non-infected patients admitted during the same period. Within 24 h of admission, plasma HBP, serum procalcitonin (PCT), white blood cell count (WBC), neutrophil-to-lymphocyte ratio (NLR) and HBP/Alb levels were collected separately and compared. The receiver operating characteristic (ROC) curve was plotted to assess the diagnostic value of each indicator for CAP patients. Utilizing the Kappa test, the consistency of each indicator used to evaluate CAP and clinical diagnosis was analyzed. Spearman correlation was used to analyze the correlation between plasma HBP and clinical indicators of CAP patients.

RESULTS

Plasma HBP, serum PCT, WBC, NLR and HBP/Alb were all elevated in the CAP group in comparison to the control group (P < 0.001). Plasma HBP, serum PCT, WBC, NLR and HBP/Alb levels did not differ statistically between antibiotic and non-antibiotic groups (P > 0.05). Plasma HBP and HBP/Alb had the highest diagnostic accuracy for CAP, the area under the ROC curve (AUC) were 0.931 and 0.938 (P < 0.0001), and the best cut-off values were 35.40 ng/mL and 0.87, respectively. In evaluating the consistency between CAP and clinical diagnosis, the Kappa values for HBP, PCT, WBC, NLR and HBP/Alb were 0.749, 0.465, 0.439, 0.566 and 0.773, respectively. Spearman correlation analysis showed that plasma HBP was positively correlated with serum PCT, WBC, NLR and HBP/Alb in CAP patients (P < 0.001).

CONCLUSIONS

Plasma HBP and HBP/Alb have a high clinical diagnostic value for CAP and can be used as good and reliable novel inflammatory markers in the emergency department for the early diagnosis of CAP patients.

TLR4-mediated release of heparin-binding protein in human airways: a co-stimulatory role for IL-26

Background

Bacterial infection causes accumulation of neutrophils that release antimicrobial proteins including heparin-binding protein (HBP). In human airways, this neutrophil accumulation can be re-capitulated via intrabronchial exposure to lipopolysaccharide (LPS), a Toll-like receptor 4 (TLR4) agonist, that also causes a local increase in the neutrophil-mobilizing cytokine IL-26. Although LPS is considered a weak stimulus for HBP release ex vivo, its effect on HBP release in human airways in vivo has not been characterized.

Methods

We determined whether intrabronchial exposure to LPS causes concomitant release of HBP and IL-26 in human airways, and whether IL-26 can enhance LPS-induced release of HBP in isolated human neutrophils.

Results

We found that the concentration of HBP was markedly increased in bronchoalveolar lavage (BAL) fluid 12, 24, and 48 hours after LPS exposure, and that it displayed a strong and positive correlation with that of IL-26. Moreover, the concentration of HBP in conditioned media from isolated neutrophils was enhanced only after co-stimulation with LPS and IL-26.

Conclusions

Taken together, our findings indicate that TLR4 stimulation causes concomitant release of HBP and IL-26 in human airways, and that IL-26 may constitute a required co-stimulant for HBP release in neutrophils, thus enabling the concerted action of HBP and IL-26 in local host defense.

Postoperative vasoplegia in lung transplantation: incidence and relation to outcome

BACKGROUND

The incidence and clinical importance of vasoplegia after lung transplantation remains poorly studied. We describe the incidence of vasoplegia and its association with complications after lung transplantation.

METHODS

Perioperative data of 279 lung transplant recipients operated on from 2015 to 2020 were retrospectively analysed.

RESULTS

Vasoplegia occurred in 41.6% of patients after lung transplantation (mild, 31.0%; moderate, 55.2%; severe, 13.8%). Compared with non-vasoplegic patients, vasoplegic patients had a higher incidence of any acute kidney injury, defined by Kidney Disease Improving Global Outcomes (KDIGO) criteria (78.5% vs 65%, P=0.015), renal replacement therapy (47.4% vs 24.5%, P<0.001), and delayed chest closure (18.4% vs 9.2%, P=0.025); were ventilated longer (70 [32-368] vs 34 [19-105] h, P<0.001); and stayed longer in the ICU (12.9 [5-30] vs 6.8 [3-20] days, P<0.001). Mortality at 30 days and 1 yr was higher in patients with vasoplegia (11.2% vs 5.5% and 20.7% vs 11.7%, P=0.039, respectively). Severe vasoplegia represented a predictor of longer-term mortality (hazard ratio=1.65, P=0.008). Underlying infectious disease, increased BMI, higher preoperative pulmonary artery systolic pressure and bilirubin levels, lower glomerular filtration rate, and increased fresh frozen plasma transfusion were predictors of vasoplegia severity. Neutrophilia, leucocytosis, and increased C-reactive protein were associated with vasoplegia, but release of the neutrophil activation markers myeloperoxidase and heparin-binding protein was similar between groups.

CONCLUSIONS

Influenced by preoperative status as well as procedural factors and inflammatory response, vasoplegia is a common and critical condition after lung transplantation with worse short-term outcomes and long-term survival.

AZU1 (HBP/CAP37) and PRKCG (PKC-gamma) may be candidate genes affecting the severity of acute mountain sickness

BACKGROUND

Acute Mountain Sickness (AMS) is one of the diseases that predispose to sudden ascent to high altitudes above 2500 m. Among the many studies on the occurrence and development of AMS, there are few studies on the severity of AMS. Some unidentified phenotypes or genes that determine the severity of AMS may be vital to elucidating the mechanisms of AMS. This study aims to explore the underlying genes or phenotypes associated with AMS severity and to provide evidence for a better understanding of the mechanisms of AMS.

METHODS

GSE103927 dataset was downloaded from the Gene Expression Omnibus database, and a total of 19 subjects were enrolled in the study. Subjects were divided into a moderate to severe AMS (MS-AMS, 9 subjects) group and a no or mild AMS (NM-AMS, 10 subjects) group based on the Lake Louise score (LLS). Various bioinformatics analyses were used to compare the differences between the two groups. Another dataset, Real-time quantitative PCR (RT-qPCR), and another grouping method were used to validate the analysis results.

RESULT

No statistically significant differences in phenotypic and clinical data existed between the MS-AMS and NM-AMS groups. Eight differential expression genes are associated with LLS, and their biological functions are related regulating of the apoptotic process and programmed cell death. The ROC curves showed that AZU1 and PRKCG had a better predictive performance for MS-AMS. AZU1 and PRKCG were significantly associated with the severity of AMS. The expression of AZU1 and PRKCG were significantly higher in the MS-AMS group compared to the NM-AMS group. The hypoxic environment promotes the expression of AZU1 and PRKCG. The results of these analyses were validated by an alternative grouping method and RT-qPCR results. AZU1 and PRKCG were enriched in the Neutrophil extracellular trap formation pathway, suggesting the importance of this pathway in influencing the severity of AMS.

CONCLUSION

AZU1 and PRKCG may be key genes influencing the severity of acute mountain sickness, and can be used as good diagnostic or predictive indicators of the severity of AMS. Our study provides a new perspective to explore the molecular mechanism of AMS.

Time course and mechanistic analysis of human umbilical cord perivascular cell mitigation of lipopolysaccharide-induced systemic and neurological inflammation

BACKGROUND AIMS

Because of their potent immunomodulatory and anti-inflammatory properties, mesenchymal stromal cells are a major focus in the field of stem cell therapy. However, the precise mechanisms underlying this are not entirely understood. Human umbilical cord perivascular cells (HUCPVCs) are a promising cell therapy candidate. This study was designed to evaluate the time course and mechanisms by which HUCPVCs mitigate lipopolysaccharide (LPS)-induced systemic and neurological inflammation in immunocompetent mice. To explore the underlying mechanisms, the authors investigated the biodistribution and fate of HUCPVCs.

METHODS

Male C57BL/6 mice were randomly allocated to four groups: control, LPS, HUCPVCs or LPS + HUCPVCs. Quantitative polymerase chain reaction, enzyme-linked immunosorbent assay and cytokine arrays were used to assess changes in pro-inflammatory mediators systemically and in the brain. Depressive-like behavioral changes were evaluated via a forced swim test. Quantum dot (qDot) labeling and immunohistochemistry were used to assess the biodistribution and fate of HUCPVCs and interactions with recipient innate immune cells.

RESULTS

A single intravenously delivered dose of HUCPVCs significantly reduced the systemic inflammation induced by LPS within the first 24 h after administration. HUCPVC treatment abrogated the upregulated expression of pro-inflammatory genes in the hippocampus and cortex and attenuated depressive-like behavior induced by LPS treatment. Biodistribution analysis revealed that HUCPVC-derived qDots rapidly accumulated in the lungs and demonstrated limited in vivo persistence. Furthermore, qDot signals were associated with major recipient innate immune cells and promoted a shift in macrophages toward a regulatory phenotype in the lungs.

CONCLUSIONS

Overall, this study demonstrates that HUCPVCs can successfully reduce systemic and neurological inflammation induced by LPS within the first 24 h after administration. Biodistribution and fate analyses suggest a critical role for the innate immune system in the HUCPVC-based immunomodulation mechanism.

Heparin-Binding Protein: A Prognostic Biomarker Associated with Severe or Complicated Community-Acquired Pneumonia in Children

Purpose

Heparin-binding protein (HBP) is a novel biomarker for inflammatory diseases. This study aimed to investigate the role of serum HBP in community-acquired pneumonia (CAP) in children and the association of HBP with the severity and prognosis.

Patients and Methods

A total of 125 children with CAP admitted to the hospital were enrolled in this retrospective study. We analyzed the differences in clinical characteristics and examination findings between patients with different levels of HBP. The severe or complicated CAP was defined as having severe radiographic findings and/or systemic manifestations. Receiver operator characteristic (ROC) curves detected the performance of biomarkers in identifying patients with severe or complicated pneumonia. The multivariate logistic regression models assessed the association between HBP levels and the severity and prognosis. Finally, we constructed a predictive model based on HBP.

Results

The rate of severe or complicated CAP for patients with upper-quartile HBP concentration (≥60 ng/mL) was 54.8%, significantly higher than that of patients with lower HBP concentration (26.6%). The level of HBP is substantially correlated with neutrophil counts, C-reactive protein, erythrocyte sedimentation rate, and serum amyloid A protein (r = 0.31, 0.26, 0.36, and 0.26, respectively). HBP achieved the highest level of discrimination for severe or complicated CAP among the biomarkers. Higher HBP concentration (≥60 ng/mL) was associated with a three-fold higher risk of severe or complicated CAP (adjusted odds ratio = 3.11, p < 0.05). A predictive model including four characteristics (HBP, lactate dehydrogenase, age and non-viral infection) for predicting severe or complicated CAP (with area under the ROC curve = 0.75) was built to create a nomogram.

Conclusion

Substantially elevated serum HBP is significantly associated with severe or complicated CAP and poor prognosis in children. This finding warrants further investigation of the function of HBP in the pathogenesis of CAP.

Heparin-binding protein as a biomarker of severe sepsis in the pediatric intensive care unit: A multicenter, prospective study

OBJECTIVES

The aim of this study is to assess Heparin-binding protein (HBP) as a diagnostic and prognostic biomarker of severe sepsis in the pediatric intensive care unit (PICU).

METHODS

A multicenter, prospective study was conducted among children with sepsis in nine PICUs in China from October 2019 to June 2021. Plasma levels of HBP, procalcitonin (PCT), C-reactive protein (CRP), lactate, and white blood cell (WBC) count were determined at enrollment and 72 h after enrollment.

RESULTS

Of 355 included patients, 132 patients were diagnosed with non-severe sepsis (referred to as sepsis), 223 patients had severe sepsis. Patients with severe sepsis had significantly elevated levels of HBP compared with sepsis (median 170.5 vs. 74.1 ng/mL, P < 0.001). Adding HBP to a diagnostic model with PCT and lactate could significantly improve the diagnostic capability for severe sepsis. The plasma levels of HBP correlated positively with the number of dysfunctional organs. After adjusting for confounding factors, the declined levels of HBP at 72 h had a significant association with decreased in-hospital mortality (adjusted odds ratio (aOR) 0.242, P < 0.001). The levels of HBP showed weak positive correlations with PCT, CRP, WBC, and no correlation to lactate.

CONCLUSIONS

HBP at enrollment can be an independent indicator for severe sepsis and the dynamic changes at 72 h can be a predictor for in-hospital mortality in PICU.

Pre-operative systemic inflammatory response index influences long-term survival rate in off-pump surgical revascularization

Coronary artery bypass revascularization is still the optimal treatment for complex coronary artery disease with good long-term results. The relation between inflammatory activation in the post-operative period and the long-term prognosis was already postulated. The possible predictive role of preoperative inflammatory indexes after the off-pump coronary artery bypass grafting technique on long term survival was the aim of the study. Study population included 171 patients with a median age of 64 years (59-64) operated on using off-pump technique between January and December 2014. Patients enrolled in the current study were followed-up for 8 years. We conducted a multivariable analysis of pre-operative and post-operative inflammatory markers based on analysis of the whole blood count. The overall survival rate was 80% for the total follow-up period, while 34 deaths were reported (30-days mortality rate of 1%). In the multivariable analysis, a pre-operative value of systemic inflammatory response index (SIRI) >1.27 (HR = 6.16, 95% CI 2.17-17.48, p = 0.012) revealed a prognostic value for long-term mortality assessment after off-pump surgery. Preoperative inflammatory activation evaluated by systemic inflammatory reaction index (SIRI) possess a prognostic value for patients with complex coronary artery disease. The SIRI value above 1.27 indicates a worse late prognosis after off-pump coronary artery bypass (AUC = 0.682, p<0.001).

The role of lung macrophages in acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is an acute and diffuse inflammatory lung injury in a short time, one of the common severe manifestations of the respiratory system that endangers human life and health. As an innate immune cell, macrophages play a key role in the inflammatory response. For a long time, the role of pulmonary macrophages in ARDS has tended to revolve around the polarization of M1/M2. However, with the development of single-cell RNA sequencing, fate mapping, metabolomics, and other new technologies, a deeper understanding of the development process, classification, and function of macrophages in the lung are acquired. Here, we discuss the function of pulmonary macrophages in ARDS from the two dimensions of anatomical location and cell origin and describe the effects of cell metabolism and intercellular interaction on the function of macrophages. Besides, we explore the treatments for targeting macrophages, such as enhancing macrophage phagocytosis, regulating macrophage recruitment, and macrophage death. Considering the differences in responsiveness of different research groups to these treatments and the tremendous dynamic changes in the gene expression of monocyte/macrophage, we discussed the possibility of characterizing the gene expression of monocyte/macrophage as the biomarkers. We hope that this review will provide new insight into pulmonary macrophage function and therapeutic targets of ARDS.

Transforming growth factor-β receptor type 2 is required for heparin-binding protein-induced acute lung injury and vascular leakage for transforming growth factor-β/Smad/Rho signaling pathway activation

Heparin-binding protein (HBP), as a granule protein secreted by polymorphonuclear neutrophils, participates in the pathophysiological process of sepsis. It has been reported that HBP is a biomarker of sepsis related to the severity of septic shock and organ dysfunction. HBP binds to vascular endothelial cells as a primary target site. However, it is still unclear whether HBP-binding protein receptors exist on the surface of endothelial cells. The effect of HBP on vascular permeability in sepsis and its mechanism needs to be explored. We conducted in vivo and in vitro studies and demonstrated that HBP binds to transforming growth factor-β receptor type 2 (TGF-β-R2) as a ligand. Glutathione S-transferase pull-down analysis revealed that HBP mainly interacts with the extracellular domain of TGF-β-R2. HBP induces acute lung injury and vascular leakage via activation of the TGF-β/SMAD2/3 signaling pathway. A permeability assay suggested that TGF-β-R2 is necessary for HBP-induced increased permeability. We also defined the role of HBP and its potential membrane receptor TGF-β-R2 in the blood-gas barrier in the pathogenesis of HBP-related acute lung injury.

The glycocalyx as a permeability barrier: basic science and clinical evidence

Preclinical studies in animals and human clinical trials question whether the endothelial glycocalyx layer is a clinically important permeability barrier. Glycocalyx breakdown products in plasma mostly originate from 99.6–99.8% of the endothelial surface not involved in transendothelial passage of water and proteins. Fragment concentrations correlate poorly with in vivo imaging of glycocalyx thickness, and calculations of expected glycocalyx resistance are incompatible with measured hydraulic conductivity values. Increases in plasma breakdown products in rats did not correlate with vascular permeability. Clinically, three studies in humans show inverse correlations between glycocalyx degradation products and the capillary leakage of albumin and fluid.

Heparin-binding protein-enhanced quick SOFA score improves mortality prediction in sepsis patients

Purpose

The Quick Sequential Organ Failure Assessment (qSOFA) score proposed by Sepsis-3 as a sepsis screening tool has shown suboptimal accuracy. Heparin-binding protein (HBP) has been shown to identify early sepsis with high accuracy. Herein, we aim to investigate whether or not HBP improves the model performance of qSOFA.

Methods

We conducted a multicenter prospective observational study of 794 adult patients who presented to the emergency department (ED) with presumed sepsis between 2018 and 2019. For each participant, serum HBP levels were measured and the hospital course was followed. The qSOFA score was used as the comparator. The data was split into a training dataset (n = 556) and a validation dataset (n = 238). The primary endpoint was 30-day all-cause mortality.

Results

Compared with survivors, non-survivors had significantly higher serum HBP levels (median: 71.5 ng/mL vs 209.5 ng/mL, p < 0.001). Serum level of HBP weakly correlated with qSOFA class (r² = 0.240, p < 0.001). Compared with the qSOFA model alone, the addition of admission HBP level to the qSOFA model significantly improved 30-day mortality discrimination (AUC, 0.70 vs. 0.80; P < 0.001), net reclassification improvement [26% (CI, 17–35%); P < 0.001], and integrated discrimination improvement [12% (CI, 9–14%); P < 0.001]. Addition of C-reactive protein (CRP) level or neutrophil-to-lymphocyte ratio (NLR) to qSOFA did not improve its performance. A web-based mortality risk prediction calculator was created to facilitate clinical implementation.

Conclusion

This study confirms the value of combining qSOFA and HBP in predicting sepsis mortality. The web calculator provides a user-friendly tool for clinical implementation. Further validation in different patient populations is needed before widespread application of this prediction model.

Dynamic changes in heparin-binding protein as a prognostic biomarker for 30-day mortality in sepsis patients in the intensive care unit

Heparin-binding protein (HBP) has been shown to be a robust predictor of the progression to organ dysfunction from sepsis, and we hypothesized that dynamic changes in HBP may reflect the severity of sepsis. We therefore aim to investigate the predictive value of baseline HBP, 24-h, and 48-h HBP change for prediction of 30-day mortality in adult patients with sepsis. This is a prospective observational study in an intensive care unit of a tertiary center. Patients aged 20 years or older who met SEPSIS-3 criteria were prospectively enrolled from August 2019 to January 2020. Plasma levels of HBP were measured at admission, 24 h, and 48 h and dynamic changes in HBP were calculated. The Primary endpoint was 30-day mortality. We tested whether the biomarkers could enhance the predictive accuracy of a multivariable predictive model. A total of 206 patients were included in the final analysis. 48-h HBP change (HBPc-48 h) had greater predictive accuracy of area under the curve (AUC: 0.82), followed by baseline HBP (0.79), PCT (0.72), lactate (0.71), and CRP (0.65), and HBPc-24 h (0.62). Incorporation of HBPc-48 h into a clinical prediction model significantly improved the AUC from 0.85 to 0.93. HBPc-48 h may assist clinicians with clinical outcome prediction in critically ill patients with sepsis and can improve the performance of a prediction model including age, SOFA score and Charlson comorbidity index.

Use of azurocidin (heparin binding protein) and interleukin-1ß as prognostic indicators in COVID-19 patients

Objective: Considering the published manuscripts on this subject, it is thought that IL-1B and azurocidin may be diagnostic and prognostic factors in severe COVID-19 disease. This study aimed to determine whether azurocidin and IL-1β are useful biomarkers and are associated with disease exacerbation in patients needing advanced treatment options. Material and Method: Our study was performed retrospectively. The data of a total of 291 patients followed in the hospital due to COVID-19 were collected. Among these patients, 66 randomly selected patients were included in this study. The control group consisted of 24 healthy individuals referred to the infectious disease outpatient clinic who weren’t no diagnosis of COVID-19 infection or any other infection. After the samples were taken into tubes without anticoagulant, they were kept at room temperature for 30 min. Afterwards, it was centrifuged at 1000xg for 15 min at +4° according to the instructions of the ELISA kit we used. The remaining serum was transferred to Eppendorf tubes and stored at −80° throughout this study. Results: A statistically significant strong positive correlation was determined between IL1β and azurocidin. A statistically significant weak positive correlation was found between IL1β and CRP, ferritin and neutrophil count, weak negative correlation with albumin, and moderately strong positive correlation with leukocyte count. Moreover, a statistically significant weak positive correlation was found between azurucidin and CRP, ferritin, and neutrophil counts. Conclusion: Azurocidin and IL-1β may serve as a potential therapeutic target for patients at risk of developing systemic multi-organ failure, with improved patient prognosis and prevention of death in severely ill patients. Although these results may contribute to the improvement of the follow-up and treatment of the patients and reduce mortality rates, there is a need for randomized controlled studies with a larger number of patients to be performed in the future.

Human Platelets Contain, Translate, and Secrete Azurocidin; A Novel Effect on Hemostasis

Platelets play a significant role in hemostasis and perform essential immune functions, evidenced by the extensive repertoire of antimicrobial molecules. Currently, there is no clear description of the presence of azurocidin in human platelets. Azurocidin is a 37 kDa cationic protein abundant in neutrophils, with microbicidal, opsonizing, and vascular permeability-inducing activity. Therefore, this work aimed to characterize the content, secretion, translation, and functions of azurocidin in platelets. Our results show the presence of azurocidin mRNA and protein in α-granules of platelet and megakaryoblasts, and stimulation with thrombin, ADP, and LPS leads to the secretion of free azurocidin as well as within extracellular vesicles. In addition, platelets can translate azurocidin in a basal or thrombin-induced manner. Finally, we found that the addition of low concentrations of azurocidin prevents platelet aggregation and activation. In conclusion, we demonstrate that platelets contain, secrete, and translate azurocidin, and this protein may have important implications for hemostasis.

Neutrophil degranulation and myocardial infarction

Myocardial infarction (MI) is one of the most common cardiac emergencies with high morbidity and is a leading cause of death worldwide. Since MI could develop into a life-threatening emergency and could also seriously affect the life quality of patients, continuous efforts have been made to create an effective strategy to prevent the occurrence of MI and reduce MI-related mortality. Numerous studies have confirmed that neutrophils play important roles in inflammation and innate immunity, which provide the first line of defense against microorganisms by producing inflammatory cytokines and chemokines, releasing reactive oxygen species, and degranulating components of neutrophil cytoplasmic granules to kill pathogens. Recently, researchers reported that neutrophils are closely related to the severity and prognosis of patients with MI, and neutrophil to lymphocyte ratio in post-MI patients had predictive value for major adverse cardiac events. Neutrophils have been increasingly recognized to exert important functions in MI. Especially, granule proteins released by neutrophil degranulation after neutrophil activation have been suggested to involve in the process of MI. This article reviewed the current research progress of neutrophil granules in MI and discusses neutrophil degranulation associated diagnosis and treatment strategies.

Application Value of Blood Heparin-Binding Protein in the Diagnosis of Acute Exacerbation of Chronic Obstructive Pulmonary Disease

Objective

To investigate the expression and clinical significance of serum heparin-binding protein (HBP), C-reactive protein (CRP), and white blood cell count (WBC) in an acute exacerbation of chronic obstructive pulmonary disease (COPD).

Methods

A prospective research model was used to select 63 patients with acute exacerbation of chronic obstructive pulmonary disease who were hospitalized in Xuzhou First People's Hospital from January 2020 to June 2020, and among the chronic obstructive pulmonary disease patients who were followed up in our hospital during the same period, 18 patients were in the stable phase, and 43 healthy patients in our hospital during the same period were selected as the healthy control group. 18 patients with stable chronic obstructive pulmonary disease were selected as the observation group, and 43 healthy people who underwent examination at the same time as the control group. For patients with acute COPD recombination, 5 ml of venous blood was collected according to whether the condition of COPD patients with acute exacerbation was stable or not. 5 ml of venous blood was collected for acute exacerbation. According to their clinical symptoms (such as cough, sputum, and asthma), dyspnea score (MRC score), and pulmonary function (FEV1 and FEV1/FVC), it is determined whether the patient's condition is stable. Patients in the stable COPD group will collect 5 ml of venous blood during the outpatient follow-up, and those in the healthy physical examination group will collect veins on the day of the physical examination. In 5 ml of blood, the levels of HBP and CRP in the blood were measured by the enzyme-linked immunosorbent method and the immunoturbidimetric method, respectively, and the peripheral blood WBC was measured by a blood cell analyzer and its supporting reagents. The differences of the three indicators in each group were statistically analyzed. Normally distributed measurement data were compared using t-test, homogeneity of variance of nonnormally distributed measurement data were compared using one-way analysis of variance, uneven variance of nonnormally distributed measurement data were compared using a rank-sum test, and Pearson linear analysis was used for correlation test. Subject working characteristic curve (ROC) was drawn, P < 0.05 means the difference is statistically significant, the receiver working characteristic curve was established, and the area under the curve (AUC) was calculated to analyze blood HBP. The value of blood CRP and peripheral blood WBC counts alone or in combination in the diagnosis of acute exacerbations of chronic obstructive pulmonary disease.

Results

The level of blood heparin-binding protein in the acute exacerbation phase was significantly higher than that in the stable phase and healthy controls (P < 0.05). In the acute exacerbation stage and stable stage group, the blood heparin binding protein, the percentage of leukocytes, neutrophils, and CRP were detected. There is a correlation between (P < 0.05) and a correlation with lung function (FEV1) (P < 0.05). The predictive value of heparin-binding protein, white blood cells, neutrophil percentage, CRP, etc. for the acute exacerbation of chronic obstructive pulmonary disease, with the area under the heparin-binding protein curve, is the largest, and compared with the stable phase, the comparison of heparin-binding protein, white blood cells, and CRP is statistically significant (P < 0.05).

Conclusion

Heparin-binding protein increases in the stable phase and acute exacerbation phase and is related to other inflammatory factors. It is one of the important inflammatory factors in chronic obstructive pulmonary disease. Heparin-binding protein, white blood cells, CRP, etc. have diagnostic and predictive value for acute exacerbation of chronic obstructive pulmonary disease. Heparin-binding protein has the best predictive result, and the combined index test has a better diagnostic predictive value, which is better than single index detection.

Heparin Binding Protein for the Early Diagnosis and Prognosis of Sepsis in the Emergency Department: The Prompt Multicenter Study

BACKGROUND

The validation of new biomarkers for the diagnosis and risk stratification of patients with sepsis at an early point is essential for successful treatment. Recent publications prompted us to investigate of heparin binding protein (HBP) for the emergency department (ED) admissions.

MATERIALS AND METHODS

In this multicenter, cross-sectional study, HBP and procalcitonin (PCT) were measured within the first hour upon admission to the ED in plasma samples of 371 patients with signs of infection. Patients were classified into non-sepsis and sepsis by the Sepsis-3 definitions and were followed up for outcome.

RESULTS

HBP was significantly higher in patients with sepsis and was positively correlated to PCT and C-reactive protein, absolute neutrophil and monocyte counts, creatinine, bilirubin and lactate. Sensitivity, specificity, positive predictive value, and negative predictive value of HBP more than 19.8 ng/mL for the diagnosis of sepsis was 66.3%, 44.9%, 49.3%, and 62.2%, respectively; and for prediction of early death was 100%, 41.0%, 4.5%, and 100%, respectively. Single HBP and PCT could not predict 28-day mortality; this was performed with sensitivity, specificity, positive predictive value, and negative predictive value 44.8%, 81.8%, 17.3%, and 94.6% when used in combination.

CONCLUSION

Admission HBP can be used as a tool for the early diagnosis of sepsis and for the risk of early death in the ED.

Serine pseudoproteases in physiology and disease

Serine proteases (SPs) constitute a very important family of enzymes, both physiologically and pathologically. The effects produced by these proteins have been explained by their proteolytic activity. However, the discovery of pharmacologically active SP molecules that show no enzymatic activity, as the so-called pseudo SPs or SP homologs (SPHs), has exposed a profoundly neglected possibility of nonenzymatic functions of these SP molecules. In this review, the most thoroughly described SPHs are presented. The main physiological domains in which SPHs operate appear to be in reproduction, embryonic development, immune response, host defense, and hemostasis. Hitherto unexplained actions of SPs should therefore be considered also as the result of the ligand-like attributes of SPs. The gain of a novel function by an SPH is a consequence of specific amino acid replacements that have resulted in a novel interaction interface or a 'catalytic trap'. Unraveling the SP/SPH interactome will provide a description of previously unknown physiological functions of SPs/SPHs, aiding the creation of innovative medical approaches.

Neutrophil-derived heparin binding protein triggers vascular leakage and synergizes with myeloperoxidase at the early stage of severe burns (With video)

Background

Burn shock caused by vascular leakage is one of the main causes of high mortality in severe burn injury. However, the pathophysiological mechanism of vascular leakage is still unclear. The purpose of this study was to explore the molecular mechanism of vascular leakage in the early stage of severe burn and provide a new target for the treatment of severe burns.

Methods

Neutrophils were isolated from human peripheral blood by magnetic beads sorting. ELISA was used to detect neutrophil-derived granule proteins and glycocalyx injury products in plasma. The vascular leakage and neutrophil movement were assessed by in vivo laser confocal imaging in mice, and high-quality video were provided.. Adhesion-related molecules were investigated by qRT-PCR. The damage to glycocalyx of mice vascular endothelial cells was observed by transmission electron microscope and scanning electron microscope. Proteomic analysis, flow cytometry and immunofluorescence were used to further study the relationship between human peripheral blood neutrophil-derived hypochlorite (HOCl) and CD44 of human vascular endothelial cells.

Results

In this study, we found that rapidly increasing activated neutrophils secrete heparin binding protein (HBP) and myeloperoxidase (MPO) after severe burn injury. Increased HBP triggers vascular leakage with synergy of MPO, results in systemic edema and burn shock. Furthermore, we found that the MPO catalytic product HOCl but not MPO triggers CD44 extracellular domain shedding from vascular endothelial cells to damage the glycocalyx. Damage to the glycocalyx results in firm adhesion of neutrophils and increases vascular leakage. However, MPO inhibitors partially protect the glycocalyx of vascular endothelial cells. The combination of HBP and MPO inhibitors markedly reduces vascular leakage and systemic edema in the early stage of severe burns.

Conclusions

Taken together, these data reveal that neutrophil-derived HBP and MPO play an important synergies role in triggering vascular leakage at the early stage of severe burns. Targeted intervention in these two biomolecules may introduce new strategies for helping to reduce large amount of fluid loss and subsequent burn shock.

Azurocidin is loaded into small extracellular vesicles via its N-linked glycosylation and promotes intravasation of renal cell carcinoma cells

Azurocidin (AZU1) is an antimicrobial protein secreted by neutrophils that acts as a chemoattractant for monocytes and macrophages and a permeabilizer of vascular endothelial cells. We previously identified AZU1 to be specifically present in extracellular vesicles (EVs) obtained from renal cell carcinoma (RCC) tissues. Here, we examined the relationship between N-linked glycosylation and AZU1 loading into small EVs (SEVs). Inhibition of N-linked glycosylation by introducing mutations in three glycosylation sites inhibited AZU1 loading into SEVs. Furthermore, SEVs released from AZU1-wild-type cells increased the Ca2+ concentration in endothelial cells and the endothelial permeability, whereas SEVs released from AZU1-mutant cells had no significant effect. Anti-AZU1 antibodies diminished the effect of SEVs on endothelial cell sheets. Collectively, we found that N-linked glycosylation of AZU1 directs its loading into SEVs, thereby enabling AZU1-positive SEVs to function as potent permeabilizers of endothelial cells and leading to enhanced transendothelial migration of RCC cells.

Heparin-Binding Protein Levels at Admission and Within 24 h Are Associated with Persistent Organ Failure in Acute Pancreatitis

BACKGROUND

Identification of patients at risk for persistent organ failure (POF) early in the course of acute pancreatitis (AP) is critical for early intervention. Heparin-binding protein (HBP) levels are closely related to inflammation. Therefore, we investigated the relationship between HBP levels and POF in patients with AP.

METHODS

This observational cohort study analyzed 66 patients with AP and 14 healthy volunteers between June 2019 and December 2019. Baseline characteristics, laboratory data, and severity scores of patients with different degrees of AP were compared. Levels of HBP were measured by ELISA. Serum HBP levels were analyzed using receiver operating characteristic curves to identify POF in AP.

RESULTS

Concentrations of serum HBP in healthy volunteers, MAP, MSAP, and SAP groups were 3.9 (range: 3.4-5) ng/ml, 5.2 (3.9-6.8) ng/ml, 5.9 (4.6-7.7) ng/ml, and 11 (8.0-13.8) ng/ml, respectively. The level of HBP in SAP patients was significantly elevated compared to the other groups (P < 0.01). HBP levels ≥ 7 ng/ml showed a specificity of 74%, a sensitivity of 90%, and an AUC of 0.82 for predicting POF.

CONCLUSIONS

HBP levels in patients with POF were significantly elevated. HBP is a useful marker for predicting severe AP.

Thrombocytosis and neutrophilia associated with oxygenator failure and protamine reaction after cardiopulmonary bypass: a case report and literature review

Thrombocytosis has been feared as a source of thrombotic complications during the conduct of cardiopulmonary bypass (CPB) for patients undergoing cardiac procedures. We present a patient urgently requiring repair/replacement of three heart valves that had preexisting myelofibrosis with thrombocytosis (platelet count of 800,000 per µl) and neutrophilia (40,000 per µl). Despite achieving an activated clotting time > 500 s with heparin and antithrombin concentrate administration prior to CPB, the pump oxygenator and reservoir demonstrated significant clot just prior to restoration of the patient's circulation. The patient subsequently suffered a severe protamine reaction that was successfully managed. A review of the literature of similar patients and the relevant cellular and biochemical mechanisms in this setting are presented, with potential therapeutic approaches to prevent such complications noted.

Diagnostic value of heparin-binding protein in the cerebrospinal fluid for purulent meningitis in children

This study aimed to investigate the diagnostic value of heparin-binding protein (HBP) in the cerebrospinal fluid of children with purulent meningitis (PM). This study included 118 children with PM diagnosed at our hospital from January 2018 to January 2020, 110 children with viral meningitis (VM) and 80 children with suspected meningitis who were ruled out by cerebrospinal fluid (CSF) analysis during the same period. HBP and white blood cell (WBC) count in the CSF, and inflammatory factors, including C-reactive protein (CRP), tumor necrosis factor (TNF)-α, and procalcitonin (PCT), were measured. Receiver-operator characteristic curves were used to analyze the predictive value of HBP, CRP, PCT, and TNF-α levels in the diagnosis of PM by CSF analysis. HBP levels in the CSF of children with PM were higher, while the CRP and serum PCT and TNF-α levels were elevated in all groups (P<0.05). In addition, HBP levels in the CSF were more accurate for the diagnosis of PM than traditional diagnostic indexes. HBP levels in the CSF can be used as an important reference for early diagnosis of PM.

Heparin-binding protein is significantly increased in acute pancreatitis

Background

Most patients with acute pancreatitis (AP) experience mild, self-limiting disease with little or no need for hospital care. However, 20–25% of patients develop a more severe and potentially life-threatening condition with progressive systemic inflammatory response syndrome (SIRS) and multiorgan failure, resulting in high morbidity and mortality rates. Predicting disease severity at an early stage is important, as immediate supportive care has been demonstrated to reduce the incidence of SIRS and organ failure, improving patient outcome. Several studies have demonstrated elevated levels of heparin-binding protein (HBP) in patients with sepsis and septic shock, and HBP is believed to play a part in endothelial dysfunction leading to vascular leakage. As HBP levels increase prior to other known biomarkers, HBP has emerged as a promising early predictor of severe sepsis with organ dysfunction.

Methods

Patients admitted to Skåne University Hospital in Malmö between 2010 and 2013 fulfilling the criteria for AP were identified in the emergency department and prospectively enrolled in this study. The primary outcome was measured levels of HBP upon hospital admission in patients with confirmed AP. Correlations among HBP concentrations, disease severity and fluid balance were considered secondary endpoints. The correlation between HBP levels and fluid balance were analysed using Pearson correlation, and the ability of HBP to predict moderately severe/severe AP was assessed using a receiver operating characteristic (ROC) curve.

Results

The overall median HBP level in this study was 529 (307–898) ng/ml. There were no significant group differences in HBP levels based on AP severity. Fluid balance differed significantly between patients with mild versus moderately severe and severe pancreatitis, but we found no correlation between HBP concentration and fluid balance.

Conclusions

HBP levels are dramatically increased in patients with AP, and these levels far exceed those previously reported in other conditions. In this study, we did not observe any significant correlation between HBP levels and disease severity or the need for intravenous fluid. Additional studies on HBP are needed to further explore the role of HBP in the pathogenesis of AP and its possible clinical implications.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-021-01910-6.

Lung Transplantation, Pulmonary Endothelial Inflammation, and Ex-Situ Lung Perfusion: A Review

Lung transplantation (LTx) is the gold standard treatment for end-stage lung disease; however, waitlist mortality remains high due to a shortage of suitable donor lungs. Organ quality can be compromised by lung ischemic reperfusion injury (LIRI). LIRI causes pulmonary endothelial inflammation and may lead to primary graft dysfunction (PGD). PGD is a significant cause of morbidity and mortality post-LTx. Research into preservation strategies that decrease the risk of LIRI and PGD is needed, and ex-situ lung perfusion (ESLP) is the foremost technological advancement in this field. This review addresses three major topics in the field of LTx: first, we review the clinical manifestation of LIRI post-LTx; second, we discuss the pathophysiology of LIRI that leads to pulmonary endothelial inflammation and PGD; and third, we present the role of ESLP as a therapeutic vehicle to mitigate this physiologic insult, increase the rates of donor organ utilization, and improve patient outcomes.

Accuracy of Heparin-Binding Protein in Diagnosing Sepsis: A Systematic Review and Meta-Analysis

OBJECTIVES

Existing studies evaluating the accuracy of heparin-binding protein for the diagnosis of sepsis have been inconsistent. We conducted a systematic review and meta-analysis to assess the totality of current evidence regarding the utility of heparin-binding protein to diagnose sepsis in patients with presumed systemic infection.

DATA SOURCE

PubMed, Embase, the China National Knowledge infrastructure, and WangFang electronic database were searched from inception to December of 2019.

STUDY SELECTION

Two independent reviewers identified eligible studies. Cohort and case-control studies, which measured serum levels of heparin-binding protein among adult patients with suspected sepsis, were eligible for inclusion.

DATA EXTRACTION

Two reviewers independently extracted data elements from the selected studies. A bivariate random-effects meta-analysis model was used to synthesize the prognostic accuracy measures. Risk of bias of studies was assessed with Quality Assessment of Diagnostic Accuracy Studies 2 tool.

DATA SYNTHESIS

We identified 26 studies with 3,868 patients in the meta-analysis. Heparin-binding protein had a pooled sensitivity of 0.85 (95% CI, 0.79-0.90) and a pooled specificity of 0.91 (95% CI, 0.82-0.96) for the diagnosis of sepsis. There was low heterogeneity between the studies (I2 = 12%), and no evidence of publication bias was detected. Heparin-binding protein had a higher sensitivity and specificity when compared with procalcitonin (0.75 [95% CI, 0.62-0.85] and 0.85 [95% CI, 0.73-0.92]) as well as C-reactive protein (0.75 [95% CI, 0.65-0.84] and 0.71 [95% CI, 0.63-0.77]). Serial measurements of heparin-binding protein also showed that heparin-binding protein levels rose significantly at least 24 hours before a diagnosis of sepsis.

CONCLUSIONS

The diagnostic ability of heparin-binding protein is favorable, demonstrating both high sensitivity and specificity in predicting progression to sepsis in critically ill patients. Future studies could assess the incremental value that heparin-binding protein may add to a multimodal sepsis identification and prognostication algorithm for critically ill patients.

Streptococcal protein SIC activates monocytes and induces inflammation

Streptococcus pyogenes is a major bacterial pathogen in the human population and isolates of the clinically important M1 serotype secrete protein Streptococcal inhibitor of complement (SIC) known to interfere with human innate immunity. Here we find that SIC from M1 bacteria interacts with TLR2 and CD14 on monocytes leading to the activation of the NF-κB and p38 MAPK pathways and the release of several pro-inflammatory cytokines (e.g. TNFα and INFγ). In human plasma, SIC binds clusterin and histidine-rich glycoprotein, and whole plasma, and these two purified plasma proteins enhanced the activation of monocytes by SIC. Isolates of the M55 serotype secrete an SIC homolog, but this protein did not activate monocytes. M1 isolates are common in cases of invasive S. pyogenes infections characterized by massive inflammation, and the results of this study indicate that the pro-inflammatory property of SIC contributes to the pathology of these severe clinical conditions.

Serum Heparin-Binding Protein as a Potential Biomarker to Distinguish Adult-Onset Still's Disease From Sepsis

Adult-onset Still’s disease (AOSD) is a systemic, multifactorial, autoinflammatory disease for which the etiopathogenesis is not well understood. Given the similarities in clinical and laboratory features between this disease and sepsis, and the differences in treatment strategies for these two diseases, specific diagnostic markers are crucial for the correct diagnosis and management of AOSD. Previous studies have shown plasma heparin-binding protein (HBP) is a promising potential biomarker for AOSD; thus, this study aimed to detect serum HBP levels in patients with AOSD or sepsis to assess its potential as a biomarker for differential diagnosis. We found that serum HBP levels were significantly higher in patients with active AOSD than that in those with inactive AOSD. Patients with sepsis had higher serum HBP levels compared with those who had active or inactive AOSD. We calculated the area under the receiver operating characteristic (ROC) curve to assess whether HBP could be used to differentiate active from inactive AOSD; this was 0.811 with sensitivity 0.650, specificity 0.811, and cutoff HBP value of 35.59 ng/ml. The area under the ROC curve for HBP as a biomarker to differentiate AOSD from sepsis was 0.653, with sensitivity 0.759, and specificity 0.552, and cutoff HBP value of 65.1 ng/ml. Taken together, the results of our study suggest that serum HBP could be a useful diagnostic biomarker to evaluate disease activity in patients with AOSD, and to differentiate AOSD from sepsis.

Thrombin-Fibrin(ogen) Interactions, Host Defense and Risk of Thrombosis

Fibrinogen is a well-known risk factor for arterial and venous thrombosis. Its function is not restricted to clot formation, however, as it partakes in a complex interplay between thrombin, soluble plasma fibrinogen, and deposited fibrin matrices. Fibrinogen, like thrombin, participates predominantly in hemostasis to maintain vascular integrity, but executes some important pleiotropic effects: firstly, as observed in thrombin generation experiments, fibrin removes thrombin from free solution by adsorption. The adsorbed thrombin is protected from antithrombins, notably α2-macroglobulin, and remains physiologically active as it can activate factors V, VIII, and platelets. Secondly, immobilized fibrinogen or fibrin matrices activate monocytes/macrophages and neutrophils via Mac-1 interactions. Immobilized fibrin(ogen) thereby elicits a pro-inflammatory response with a reciprocal stimulating effect of the immune system on coagulation. In contrast, soluble fibrinogen prohibits recruitment of these immune cells. Thus, while fibrin matrices elicit a procoagulant response, both directly by protecting thrombin and indirectly through the immune system, high soluble fibrinogen levels might protect patients due to its immune diminutive function. The in vivo influence of the 'protective' plasma fibrinogen versus the 'pro-thrombotic' fibrin matrices on thrombosis should be explored in future research.

Investigation and assessment of neutrophil dysfunction early after severe burn injury

BACKGROUND

Extensive burn injury results in a complex immune response that is associated with mortality and prognosis. Studies on acquired immune and the development of sepsis in burn patients have been reported. However, one of the main cells in innate immune, neutrophil dysfunction in the burn shock stage has not been thoroughly characterized.

METHODS

Neutrophil chemotaxis, expression of neutrophil surface markers (P2X1 receptor, [P2RX1]), degranulation (myeloperoxidase [MPO], heparin-binding protein [HBP], matrix metalloproteinase-9 [MMP-9] and neutrophil elastase [NE]), oxidative burst capacity, neutrophil extracellular trap (NET) generation, phagocytosis and apoptosis were measured in 18 patients with major burns (≥30% total body surface area [TBSA]) within 48 h after burn injury. In addition, circulating neutrophils and vascular permeability in mice model with 30% TBSA third-degree burns were also observed and investigated.

RESULTS

Neutrophil functions were reduced considerably in burn shock stage, which was characterized by decreased chemotaxis, phagocytosis and abnormal bactericidal function. Increased release of heparin-binding protein (HBP) and the expression of P2RX1 on the neutrophil surface are related to fluid leakage and decreased chemotaxis during burn shock stage, respectively. The combination of HBP concentration in plasma and P2RX1 expression on neutrophils gives a better prediction of neutrophil dysfunction in burn-injured patients.

CONCLUSION

Neutrophil dysfunction plays a key role in the development of burn injury. Targeting the restoration of neutrophil function may be a feasible therapeutic intervention to help reduce fluid loss during shock and the severity of subsequent infection.

Heparin-binding protein levels correlate with aggravation and multiorgan damage in severe COVID-19

Background

Critically ill coronavirus disease 2019 (COVID-19) patients may suffer persistent systemic inflammation and multiple organ failure, leading to a poor prognosis.

Research question

To examine the relevance of the novel inflammatory factor heparin-binding protein (HBP) in critically ill COVID-19 patients, and evaluate the correlation of the biomarker with disease progression.

Study design and methods

18 critically ill COVID-19 patients who suffered from respiratory failure and sepsis, including 12 cases who experienced a rapidly deteriorating clinical condition and six cases without deterioration, were investigated. They were compared with 15 age- and sex- matched COVID-19-negative patients with respiratory failure. Clinical data were collected and HBP levels were investigated.

Results

HBP was significantly increased in critically ill COVID-19 patients following disease aggravation and tracked with disease progression. HBP elevation preceded the clinical manifestations for up to 5 days and was closely correlated with patients’ pulmonary ventilation and perfusion status.

Interpretation

HBP levels are associated with COVID-19 disease progression in critically ill patients. As a potential mediator of disease aggravation and multiple organ injuries that are triggered by continuing inflammation and oxygen deficits, HBP warrants further study as a disease biomarker and potential therapeutic target.

For the first time, this study observed that heparin-binding protein (HBP) was significantly increased in critically ill COVID-19 patients during disease aggravation, which highlights HBP as a disease mediator and a potential therapeutic targethttps://bit.ly/35dz88C

Pathogenic Mechanisms of Streptococcal Necrotizing Soft Tissue Infections

Necrotizing skin and soft tissue infections (NSTIs) are severe life-threatening and rapidly progressing infections. Beta-hemolytic streptococci, particularly S. pyogenes (group A streptococci (GAS)) but also S. dysgalactiae subsp. equisimilis (SDSE, most group G and C streptococcus), are the main causative agents of monomicrobial NSTIs and certain types, such as emm1 and emm3, are over-represented in NSTI cases. An arsenal of bacterial virulence factors contribute to disease pathogenesis, which is a complex and multifactorial process. In this chapter, we summarize data that have provided mechanistic and immuno-pathologic insight into host-pathogens interactions that contribute to tissue pathology in streptococcal NSTIs. The role of streptococcal surface associated and secreted factors contributing to the hyper-inflammatory state and immune evasion, bacterial load in the tissue and persistence strategies, including intracellular survival and biofilm formation, as well as strategies to mimic NSTIs in vitro are discussed.

The Role of Neutrophils and Neutrophil Extracellular Traps in Acute Pancreatitis

Leukocyte invasion (neutrophils and monocytes/macrophages) is closely related to the severity of acute pancreatitis (AP) and plays an important role in the systemic inflammatory response and other organ injuries secondary to AP. Increased and sustained activation of neutrophils are major determinants of pancreatic injury and inflammation. After the onset of AP, the arrival of the first wave of neutrophils occurs due to a variety of triggers and is critical for the exacerbation of inflammation. In this review, we summarize the functional characteristics of neutrophils, elastase, and heparin-binding proteins in granules, the mechanisms of neutrophil recruitment and the role of neutrophil extracellular traps (NETs) in AP.

Myeloperoxidase mediated alteration of endothelial function is dependent on its cationic charge

Endothelial cell (EC) glycocalyx (GLX) comprise a multicomponent layer of proteoglycans and glycoproteins. Alteration of its integrity contributes to chronic vascular inflammation and leads to the development of cardiovascular diseases. Myeloperoxidase (MPO), a highly abundant enzyme released by polymorphonuclear neutrophils, binds to the GLX and deleteriously affects vascular EC functions. The focus of this study was to elucidate the mechanisms of MPO-mediated alteration of GLX molecules, and to unravel subsequent changes in endothelial integrity and function. MPO binding to GLX of human ECs and subsequent internalization was mediated by cell surface heparan sulfate chains. Moreover, interaction of MPO, which is carrying a cationic charge, with anionic glycosaminoglycans (GAGs) resulted in reduction of their relative charge. By means of micro-viscometry and atomic force microscopy, we disclosed that MPO can crosslink GAG chains. MPO-dependent modulation of GLX structure was further supported by alteration of wheat germ agglutinin staining. Increased expression of ICAM-1 documented endothelial cell activation by both catalytically active and also inactive MPO. Furthermore, MPO increased vascular permeability connected with reorganization of intracellular junctions, however, this was dependent on MPO's catalytic activity. Novel proteins interacting with MPO during transcytosis were identified by proteomic analysis. Altogether, these findings provide evidence that MPO through interaction with GAGs modulates overall charge of the GLX, causing modification of its structure and thus affecting EC function. Importantly, our results also suggest a number of proteins interacting with MPO that possess a variety of cellular localizations and functions.

Blood molecular markers associated with COVID-19 immunopathology and multi-organ damage

COVID-19 is characterized by dysregulated immune responses, metabolic dysfunction and adverse effects on the function of multiple organs. To understand host responses to COVID-19 pathophysiology, we combined transcriptomics, proteomics, and metabolomics to identify molecular markers in peripheral blood and plasma samples of 66 COVID-19-infected patients experiencing a range of disease severities and 17 healthy controls. A large number of expressed genes, proteins, metabolites, and extracellular RNAs (exRNAs) exhibit strong associations with various clinical parameters. Multiple sets of tissue-specific proteins and exRNAs varied significantly in both mild and severe patients suggesting a potential impact on tissue function. Chronic activation of neutrophils, IFN-I signaling, and a high level of inflammatory cytokines were observed in patients with severe disease progression. In contrast, COVID-19-infected patients experiencing milder disease symptoms showed robust T-cell responses. Finally, we identified genes, proteins, and exRNAs as potential biomarkers that might assist in predicting the prognosis of SARS-CoV-2 infection. These data refine our understanding of the pathophysiology and clinical progress of COVID-19.

Biomarkers in urinary tract infections - which ones are suitable for diagnostics and follow-up?

Introduction: Urinary tract infections (UTIs) are one of the most common infections worldwide. Under special circumstances, clinicians must rely on laboratory findings, which might have a weak predicting value, misguiding the practitioners and leading to incorrect diagnosis and overuse of antibiotics. Therefore, there is an urgent need for reliable biomarkers in UTIs. Methods: We performed a literature search for biomarkers used in UTIs from January 1999 until May 2020. We used "urinary tract infection" and "biomarker" as the main key words in the PubMed, Medline and Cochrane databases. After peer review, we excluded the duplicates and identified the suitable articles, from which we collected the data and divided the available biomarkers into 5 groups: i) conventional markers; ii) promising, thoroughly studied biomarkers; iii) promising biomarkers that need further studies; iv) biomarkers of unknown significance; v) controversial, not useful markers. Results: We found 131 articles, mostly from the paediatric population. Neutrophil gelatinase-associated lipocalin (NGAL) and interleukins (IL) have a leading role in diagnosing and differentiating UTIs based on a lot of observational, comparative trials. Heparin Binding Protein (HBP), Lactoferrin (LF), Heat-Shock Protein-70 (HSP-70), Human Defensin-5 (HD-5), Lipopolysaccharide Binding Protein (LBP) and mass spectrometry studies are promising, but confirming data are lacking. The measurable components of the innate immune system and local host cell response could be appropriate biomarkers, but their significance is currently unknown. Conclusions: Conventional biomarkers for UTIs have low specificity. The use of urinary NGAL and interleukins could improve the sensitivity and specificity of laboratory diagnosis of UTIs.

Heparin-binding protein as a novel biomarker for sepsis-related acute kidney injury

Background

Sepsis-related acute kidney injury (AKI) is associated with high morbidity and mortality among patients. Underlying pathomechanisms include capillary leakage and fluid loss into the interstitial tissue and constant exposure to pathogens results in activation of inflammatory cascades, organ dysfunction and subsequently organ damage.

Methods

To identify novel factors that trigger sepsis-related acute kidney injury, plasma levels of Granzyme A, as representative of a lymphocyte-derived protease, and heparin-binding protein as indicator for neutrophil-derived mediators, were investigated retrospectively in 60 sepsis patients.

Results

While no association was found between plasma levels of lymphocyte-derived Granzyme A and the incidence of sepsis-related AKI, sepsis patients with AKI had significantly higher plasma levels of heparin-binding protein compared to those without AKI. This applies both to heparin-binding protein peak values (43.30 ±  23.34 vs. 30.25 ±  15.63 pg/mL; p = 0.005) as well as mean values (27.93 ±  14.39 vs. 22.02 ±  7.65 pg/mL; p = 0.021). Furthermore, a heparin-binding protein cut-off value of 23.89 pg/mL was established for AKI diagnosis.

Conclusion

This study identifies the neutrophil-derived heparin-binding protein as a valuable new biomarker for AKI in sepsis. Beyond the diagnostic perspective, this offers prospect for further research on pathogenesis of AKI and novel therapeutic approaches.

Phagocyte Escape of Leptospira: The Role of TLRs and NLRs

The spirochetal bacteria Leptospira spp. are causative agents of leptospirosis, a globally neglected and reemerging zoonotic disease. Infection with these pathogens may lead to an acute and potentially fatal disease but also to chronic asymptomatic renal colonization. Both forms of disease demonstrate the ability of leptospires to evade the immune response of their hosts. In this review, we aim first to recapitulate the knowledge and explore the controversial data about the opsonization, recognition, intracellular survival, and killing of leptospires by scavenger cells, including platelets, neutrophils, macrophages, and dendritic cells. Second, we will summarize the known specificities of the recognition or escape of leptospire components (the so-called microbial-associated molecular patterns; MAMPs) by the pattern recognition receptors (PRRs) of the Toll-like and NOD-like families. These PRRs are expressed by phagocytes, and their stimulation by MAMPs triggers pro-inflammatory cytokine and chemokine production and bactericidal responses, such as antimicrobial peptide secretion and reactive oxygen species production. Finally, we will highlight recent studies suggesting that boosting or restoring phagocytic functions by treatments using agonists of the Toll-like or NOD receptors represents a novel prophylactic strategy and describe other potential therapeutic or vaccine strategies to combat leptospirosis.

TNFR1, TNFR2, neutrophil gelatinase-associated lipocalin and heparin binding protein in identifying sepsis and predicting outcome in an intensive care cohort

To date no biomarkers can aid diagnosing sepsis with adequate accuracy. We set out to assess the ability of Tumor necrosis factor receptor (TNFR) 1 and 2, Neutrophil gelatinase-associated lipocalin (NGAL) and Heparin binding protein (HBP) to discriminate sepsis from non-infected critically ill patients in a large ICU cohort, and to evaluate their value to predict mortality at 30 days. Adult patients admitted to the ICU with an arterial catheter were included. Clinical data and blood samples were prospectively recorded daily. Diagnoses were set retrospectively. Descriptive statistics and logistic regression models were used. NGAL, TNFR1 and TNFR2 were higher in sepsis patients compared to other diagnoses, as well as in non-survivors compared to survivors. In addition, these biomarkers increased with increasing stages of acute kidney injury. TNFR1 and TNFR2 performed similarly to NGAL and CRP in identifying sepsis patients, but they performed better than CRP in predicting 30-day mortality in this ICU cohort. Thus, TNFR1 and TNFR2 may be particularly useful in identifying high risk sepsis patients and facilitate relevant health care actions in this group of sepsis patients.

Repeated measures of Heparin-binding protein (HBP) and procalcitonin during septic shock: biomarker kinetics and association with cardiovascular organ dysfunction

Background

Heparin-binding protein (HBP) is a neutrophil-derived pro-inflammatory protein, an inducer of endothelial dysfunction and vascular permeability and a promising prognostic biomarker in sepsis. This exploratory study aims to describe the kinetics of plasma HBP during septic shock and investigate an association between repeated measures of HBP concentration and cardiovascular organ dysfunction severity.

Methods

We included patients at or above 18 years with suspected septic shock on admission to the intensive care unit (ICU) during 2014 and 2016 to 2018. Plasma samples were collected from ICU admission and every 4 h for 72 h or until death or ICU discharge and batch analysed for HBP. Mean arterial blood pressure (MAP) and noradrenaline dose (NA dose) were recorded at each sampling time point, and systemic vascular resistance index (SVRI) was recorded when available from non-invasive monitoring. The association between HBP, NA dose, MAP and SVRI was assessed respectively using mixed-effects linear regression models. Procalcitonin (PCT) was used as a comparator.

Results

A total of 24 patients were included. The kinetics of plasma HBP was highly variable over time, with occasional >2-fold increases and decreases in between 4-h measurements. Every 100 ng/mL increase in HBP corresponded to a 30% increase in NA dose in a crude model (95% CI 3 to 60%, p = 0.03, n_obs = 340), a 1.4-mmHg decrease in MAP in an adjusted model (95% CI − 1 to − 2.3 mmHg, p = 0.04) or a 99 dyne s cm⁻⁵ m⁻² decrease in SVRI in another adjusted model (95% CI − 36 to − 162, p = 0.002, n_pat = 13). PCT had a stronger association to NA dose than HBP in a crude model but was not significantly associated to NA dose, MAP or SVRI in any time-adjusted model.

Conclusions

Plasma HBP displayed a highly variable kinetic pattern during septic shock and was significantly associated to cardiovascular organ dysfunction severity over time.

Neutrophils Enhance Cutaneous Vascular Dilation and Permeability to Aggravate Psoriasis by Releasing Matrix Metallopeptidase 9

Neutrophil infiltration and papillary vessel dilation are hallmarks of the initiation phase of psoriatic lesions. However, how neutrophils aggravate psoriasis development during transendothelial migration and the interaction between neutrophils and cutaneous vascular endothelial cells are less well-understood. In this study, we reported that neutrophils and cutaneous vascular endothelial cells activated each other when neutrophils migrated through the cutaneous endothelial barrier. In addition, neutrophil infiltration into skin lesions caused vascular remodeling including cutaneous vasodilation and enhanced vascular permeability in vivo and in vitro. Microarray gene profile data showed that matrix metallopeptidase (MMP)-9 was overexpressed in psoriatic neutrophils, and zymography assay further validated the bioactivity of MMP-9 secreted by psoriatic neutrophils. Moreover, MMP-9 activated vascular endothelial cells through the extracellular signal‒regulated kinase 1/2 and p38-MAPK signaling pathways, enhancing CD4⁺ T-cell transmigration in vitro. Correspondingly, an MMP-9 inhibitor significantly reduced cutaneous vasodilation, vascular permeability, and psoriatic symptoms in an imiquimod- or IL-23‒induced psoriasiform mouse model. Overall, our study demonstrates that neutrophil-derived MMP-9 induces cutaneous vasodilation and hyperpermeability by activating cutaneous vascular endothelial cells, thus facilitating psoriatic lesion development, which increases our knowledge on the role of neutrophils in the pathogenesis of psoriasis.