Skin collagen synthesis is depressed in patients with severe sepsis

Neo-epitope detection identifies extracellular matrix turnover in systemic inflammation and sepsis: an exploratory study

BACKGROUND

Sepsis is associated with high morbidity and mortality, primarily due to systemic inflammation-induced tissue damage, resulting organ failure, and impaired recovery. Regulated extracellular matrix (ECM) turnover is crucial for maintaining tissue homeostasis in health and in response to disease-related changes in the tissue microenvironment. Conversely, uncontrolled turnover can contribute to tissue damage. Systemic Inflammation is implicated to play a role in the regulation of ECM turnover, but the relationship between the two is largely unclear.

METHODS

We performed an exploratory study in 10 healthy male volunteers who were intravenously challenged with 2 ng/kg lipopolysaccharide (LPS, derived from Escherichia coli) to induce systemic inflammation. Plasma samples were collected before (T0) and after (T 1 h, 3 h, 6 h and 24 h) the LPS challenge. Furthermore, plasma was collected from 43 patients with septic shock on day 1 of ICU admission. Circulating neo-epitopes of extracellular matrix turnover, including ECM degradation neo-epitopes of collagen type I (C1M), type III (C3M), type IV (C4Ma3), and type VI (C6M), elastin (ELP-3) and fibrin (X-FIB), as well as the ECM synthesis neo-epitopes of collagen type III (PRO-C3), collagen type IV (PRO-C4) and collagen type VI (PRO-C6) were measured by ELISA. Patient outcome data were obtained from electronic patient records.

RESULTS

Twenty-four hours after LPS administration, all measured ECM turnover neo-epitopes, except ELP-3, were increased compared to baseline levels. In septic shock patients, concentrations of all measured ECM neo-epitopes were higher compared to healthy controls. In addition, concentrations of C6M, ELP-3 and X-FIB were higher in patients with septic shock who ultimately did not survive (N = 7) compared to those who recovered (N = 36).

CONCLUSION

ECM turnover is induced in a model of systemic inflammation in healthy volunteers and was observed in patients with septic shock. Understanding interactions between systemic inflammation and ECM turnover may provide further insight into mechanisms underlying acute and persistent organ failure in sepsis.

Bone homeostasis disorders increased the mortality of sepsis patients: A preliminary retrospective cohort study

Introduction

Sepsis is a common clinical syndrome and nearly 20% of all deaths are related to sepsis. As an important part of the body, bone homeostasis disorders are closely related to inflammatory response, but the correlation between bone homeostasis and sepsis, sepsis shock was unknown. The objective of this study was to explore the relation of bone homeostasis on sepsis and sepsis shock.

Methods

In this retrospective cohort study, patients were enrolled between April 2018 and May 2022 from Beijing Chaoyang hospital. Primary outcomes were serum indicators reflected bone homeostasis, such as cross-linked carboxy-terminal telopeptide of type I collagen (CTX-I), tartrate-resistant acid phosphatase 5b (TRACP-5b) and piezo-type mechanosensitive ion channel component 1 (PIEZO1).

Results

The data were analyzed retrospectively. among 88 evaluable patients, 45 were sepsis (19 were sepsis shock) and 43 were non-sepsis. There was no significant difference in age, gender, BMI, combination diseases, operation time, intraoperative blood loss, and hospital stay. Patients with sepsis or sepsis shock had higher serum CTX-I, TRACP-5b, PIEZO1 (p < 0.05). Spearman’s rank correlation test showed that CTX-I, TRACP-5b, PIEZO1 and the three together (CTX-I + TRACP-5b + PIEZO1) had strong correlation with sepsis or sepsis shock (p < 0.05). The receiver operating characteristic curve (ROC) and precision-recall curve (PRC) showed that these indicators could predict the occurrence of sepsis or sepsis shock (p < 0.05). Besides, decision curve analysis (DCA) and interventions avoided curve (IAC) displayed a high net benefit of bone homeostasis disorders indicators on sepsis or sepsis shock. Kaplan–Meier survival curves revealed that sepsis or shock patients with high value indicators (>0.47227) had a higher mortality (p < 0.05).

Conclusion

Bone homeostasis disorders could increase the mortality of sepsis and sepsis shock patients.

Growth factor expression is enhanced and extracellular matrix proteins are depressed in healing skin wounds in septic patients compared with healthy controls

Sepsis manifests as a dysregulated immune response to infection, damaging organs. Skin has a critical role in protecting the body. In sepsis, skin wound healing is impaired. The mechanisms behind it have been poorly studied. In this study, suction blister wounds were induced on intact abdominal skin in 15 septic patients. A single blister wound was biopsied from each patient and from 10 healthy controls. Immunohistochemical staining of growth factors and extracellular matrix (ECM) proteins was performed. Significance (p < 0.05) of the differences was calculated. The following growth factors were overexpressed in the skin of septic patients compared with healthy controls: epithelial growth factor (intact epithelium p = 0.007, migrating epithelium p = 0.038), vascular epithelial growth factor (intact epithelium p < 0.001, migrating epithelium p = 0.011) and transforming growth factor beta (migrating epithelium p = 0.002). The expression of syndecan‐1 was upregulated in the skin of septic patients compared with healthy controls (intact epithelium p = 0.048, migrating epithelium p = 0.028). The following ECM proteins had lower expression in the epithelium in septic patients than in healthy controls: tenascin‐C (migrating epithelium p = 0.03) and laminin‐332 (intact epithelium p = 0.036). In sepsis, growth factor and syndecan expression was enhanced, while ECM and basement membrane proteins were mostly depressed.

Inhibitory effects of serum from sepsis patients on epithelial cell migration in vitro: a case control study

Background

Sepsis delays wound re-epithelialization. In this study we explored the effect of human sepsis sera as well as the effects of cytokines, growth factors and exosomes of sepsis sera treated normal fibroblasts (NF) on keratinocyte migration and proliferation in vitro.

Methods

Serum samples were taken on days 1, 4, and 9 from 44 patients diagnosed with severe sepsis, and from 14 matching healthy controls. We evaluated the effects of sepsis serum with or without TNF-α, EGF, EGF receptor inhibitor or exosomes of sepsis sera treated NF on human keratinocyte (HaCaT) proliferation (BrdU assay), viability (MTT assay), and migration (horizontal wound healing model). Cytokine levels of sepsis and healthy sera were measured by multiplex assay. Comparisons between groups were carried out using SPSS statistics and P < 0.05 was considered significant.

Results

Severe-sepsis sera collected on days 1, 4, and 9 reduced keratinocyte proliferation by 6% (P = 0.005), 20% (P = 0.001), and 18% (P = 0.002), respectively, compared to control sera. Cell viability in cultures exposed to sepsis sera from days 4 and 9 was reduced by 38% (P = 0.01) and 58% (P < 0.001), respectively. Open-surface wounds exposed to sepsis sera from days 1 and 4 were larger than those exposed to sera from healthy controls (60 vs. 31%, P = 0.034 and 66 vs. 31%, P = 0.023, respectively). Exosomes of sepsis or healthy sera treated NF inhibited keratinocyte migration. We detected higher serum levels of cytokines TNF-α (5.7 vs. 0.7 pg/ml, P < 0.001), IL-6 (24.8 vs. 3.8 pg/ml, P < 0.001), IL-10 (30.0 vs. 11.9 pg/ml, P = 0.040), and VEGF (177.9 vs. 48.1 pg/ml, P = 0.018) in sepsis sera. Levels of EGF were significantly lower in sepsis sera than in that of healthy controls (6.5 vs. 115.6 pg/ml, P < 0.001). Sepsis serum supplemented with EGF 5 ng/ml and TNF-α in all concentrations improved keratinocyte migration.

Conclusions

Keratinocyte viability, proliferation and migration were reduced in severe sepsis in vitro. Exosomes from NF added in healthy or sepsis serum media inhibited keratinocyte migration. Decreased levels of EGF in sepsis sera may partially explain the delay of wound healing with severe-sepsis patients. Increased levels of TNF-α in sepsis sera do not explain diminished keratinocyte migration.

Blister fluid and serum cytokine levels in severe sepsis in humans reflect skin dysfunction

BACKGROUND

Knowledge of sepsis-related end-organ inflammation in vivo is limited. We investigated the cytokine response in skin and in serum in sepsis and its relation to multiorgan failure (MOF) and survival.

METHODS

Cytokines were analysed in serum and in suction blister fluid of intact skin of 44 patients with severe sepsis and 15 healthy controls. Blister fluid and serum samples were collected within 48 h of the first sepsis-induced organ failure. This is a substudy of a larger follow-up study on wound healing in sepsis.

RESULTS

Cytokine levels were higher in patients with sepsis vs. controls (interleukin [IL]-10, blisters: 65.9 vs. 4.3 pg/ml, P < 0.001, serum: 25.7 vs. 4.5 pg/ml, P = 0.004; IL-6, blisters: 41.9 vs. 0.03 pg/ml, P < 0.001, serum: 45.5 vs. 2.1 pg/ml, P < 0.001). Patients with MOF had higher levels of IL-10 (116.4 vs. 21.3 pg/ml, P = 0.015), IL-4 (0.7 vs. 0.07 pg/ml, P = 0.013) and basic fibroblast growth factor (bFGF) (25.9 vs. 9.5 pg/ml, P = 0.027) in blister fluid than patients without MOF. In blister fluid, survivors had lower levels of IL-10 (43.3 vs. 181.9 pg/ml, P = 0.024) and bFGF (15.8 vs. 31.9 pg/ml, P = 0.006) than non-survivors. In serum, survivors had higher levels of vascular endothelial growth factor (VEGF) (152.2 vs. 14.7 pg/ml, P = 0.012) and lower levels of IL-6 (38.5 vs. 91.1 pg/ml, P = 0.011) than non-survivors. The blister fluid levels of bFGF, TNF and VEGF did not correlate with the serum levels.

CONCLUSIONS

Cytokine responses in skin blister fluid in patients with sepsis differed from those in healthy controls.

Procollagen type III aminoterminal propeptide as biomarker of host response in severe sepsis

PURPOSE

The purpose of this study is to test the hypothesis that procollagen type III aminoterminal propeptide (PIIINP) is early elevated in septic episodes and can indicate the acute organ dysfunction/failure characterizing severe sepsis.

MATERIALS AND METHODS

This prospective study included 107 consecutive septic patients (44 with sepsis, 13 with severe sepsis, and 50 with septic shock) and 45 controls. After blood sampling (within 48 hours after onset of septic episodes), serum was assayed. Patients were followed up, and their disease severity was daily evaluated.

RESULTS

Procollagen type III aminoterminal propeptide (median [range]) increased in patients with sepsis (9.4 [2.2-42.4] ng/mL) compared with controls (3.6 [1.9-4.9] ng/mL; P<.001), exhibiting further significant increase in patients with severe sepsis and septic shock (19.5 [6.0-52.4] and 20.2 [1.8-89.2] ng/mL, respectively; P<.01-.001 vs sepsis). Among biomarkers of host response severity, PIIINP was the sole that was independently associated with severe sepsis/septic shock (P=.01). The area under the receiver operating characteristic curve for PIIINP to predict which patients with sepsis would eventually develop severe sepsis/septic shock was 0.87; the cutoff of 12 ng/mL had sensitivity 82% and specificity 89%.

CONCLUSIONS

Increased serum PIIINP can signify severe sepsis/septic shock and predict which patients with sepsis will eventually develop severe sepsis/septic shock, thus representing a biomarker of risk stratification of patients with sepsis.

Does lactate measurement performed on admission predict clinical outcome on the intensive care unit? A concise systematic review

Background

There is a need for practical, efficient and effective prognostic markers for patients admitted to the intensive care unit (ICU) with sepsis, to identify patients at highest risk and guide and monitor treatment. Although many biomarkers and scoring systems have been advocated, none have yet achieved this elusive combination. Most ICUs already use blood lactate concentrations to monitor patients but the evidence base for this application is unclear.

Methods

A systematic review of the last five years of evidence of effectiveness of lactate measurement in prediction of outcome in ICUs was performed.

Results

It was found that there is a lack of high-quality evidence, and no specific studies of prognostic accuracy. d- or l-Lactate concentrations measured in plasma, serum, whole blood or colonic washings were raised at admission in almost all patient groups, and were higher in patient groups who had the worst outcomes (in-hospital mortality, sequential organ failure). However, there was significant overlap in individual concentrations measured in those who died within 28 days of admission, or who developed multiple organ failure, and those who did not. For serum l-lactate concentrations, no specific cut-off value capable of predicting in-hospital mortality or sequential organ failure could be recommended.

Conclusions

The evidence reviewed suggested that whole blood, plasma or serum lactate measurement could not provide specific prognostic information for individual patients. There may be a role for monitoring for normalization of serum d- or l-lactate concentrations during goal-directed therapy in the ICU but further good-quality studies are needed. Measurement of the d-lactate stereoisomer shows promise, such that further studies are warranted.