Blood platelets and sepsis pathophysiology: A new therapeutic prospect in critically [corrected] ill patients?

Relationship between thrombocytopenia and prognosis in children with septic shock: a retrospective cohort study

Septic shock is a life-threatening disease worldwide often associated with thrombocytopenia. Platelets play a crucial role in bridging the gap between immunity, coagulation, and endothelial cell activation, potentially influencing the course of the disease. However, there are few studies specifically evaluating the impact of thrombocytopenia on the prognosis of pediatric patients. Therefore, the study investigates effects of early thrombocytopenia in the prognosis of children with septic shock. Pediatric patients with septic shock from 2015 to 2022 were included monocentrically. Thrombocytopenia was defined as a platelet count of <100 × 109/L during the first 24 hours of septic shock onset. The primary outcome was the 28-day mortality. Propensity score matching was used to pair patients with different platelet counts on admission but comparable disease severity. A total of 419 pediatric patients were included in the analysis. Patients with thrombocytopenia had higher 28-day mortality (55.5% vs. 38.7%, p = .005) compared to patients with no thrombocytopenia. Thrombocytopenia was associated with reduced 28-PICU free days (median value, 0 vs. 13 days, p = .003) and 28-ventilator-free (median value, 0 vs. 19 days, p = .001) days. Among thrombocytopenia patients, those with platelet count ≤50 × 109/L had a higher 28-day mortality rate (63.6% vs. 45%, p = .02). Multiple logistic regression showed that elevated lactate (adjusted odds ratio (OR) = 1.11; 95% confidence interval (CI): 1.04-1.17; P <0.001) and white blood cell (WBC) count (OR = 0.97; 95% CI: 0.95-0.99; p = .003) were independent risk factors for the development of thrombocytopenia. Thrombocytopenia group had increased bleeding events, blood product transfusions, and development of organ failure. In Kaplan-Meier survival estimates, survival probabilities at 28 days were greater in patients without thrombocytopenia (p value from the log-rank test, p = .004). There were no significant differences in the type of pathogenic microorganisms and the site of infection between patients with and without thrombocytopenia. In conclusion, thrombocytopenia within 24 hours of shock onset is associated with an increased risk of 28-day mortality in pediatric patients with septic shock.

EGFR of platelet regulates macrophage activation and bacterial phagocytosis function

BACKGROUND

Beyond their crucial role in hemostasis, platelets possess the ability to regulate inflammation and combat infections through various mechanisms. Stringent control of macrophage activation is essential during innate immune responses in sepsis. Macrophages are considered crucial phagocytic cells that aid in the elimination of pathogens. Platelet interactions with monocytes-macrophages are known to be significant in the response against bacterial infections, but the primary mediator driving these interactions remains unclear. EGFR plays critical role in the regulation of inflammation and infection through various mechanisms.

RESULTS

The overexpression of platelets by thrombopoietin (TPO) leads to the sequestration of both pro-inflammatory (IL-6/IL-1) and anti-inflammatory (IL-10) cytokines in the organ tissue of septic mice. Epidermal growth factor receptor (EGFR) is critical for platelet activation in sepsis. EGFR-licensed platelets enhance macrophage immune function, including the production of reactive oxygen species (ROS) and the clearance of bacteria. Platelet EGFR also induces M1 macrophage polarization by increasing the expression of inducible nitric oxide synthase (iNOS) and CD64.

CONCLUSION

EGFR can activate platelet immune function. Moreover, activated platelets efficiently regulate bacterial phagocytosis and pro-inflammatory function of macrophages through an EGFR-dependent pathway.

Factors influencing recurrent emergency department visits for mild acute respiratory tract infections caused by the influenza virus

Background

Seasonal viral outbreaks, exemplified by influenza A and B viruses, lead to spikes in emergency department (ED) visits, straining healthcare facilities. Addressing ED overcrowding has become paramount due to its implications for patient care and healthcare operations. Recurrent visits among influenza patients remain an underexplored aspect, necessitating investigation into factors influencing such revisits.

Methods

Conducted within a tertiary care university hospital, this study adopts an observational retrospective cohort design. The study included adult patients with acute respiratory symptoms diagnosed with influenza using rapid antigen testing. The cohort was divided into single and recurrent ED visitors based on revisits within 10 days of initial discharge. A comparative analysis was performed, evaluating demographics, laboratory parameters, and clinical process data between recurrent visitors and single visitors.

Results

Among 218 patients, 36.2% (n = 139) experienced recurrent ED visits. Age and gender disparities were not significant. Antibiotics were prescribed for 55.5% (n = 121) and antivirals for 92.7% (n = 202) of patients, with no notable influence on recurrence. Recurrent visitors exhibited lower monocyte counts, hemoglobin levels, higher PDW and P-LCR percentages, and increased anemia prevalence (p = 0.036, p = 0.01, p = 0.004, p = 0.029, p = 0.017, respectively). C-reactive protein (CRP) levels did not significantly affect recurrence.

Conclusion

This study highlights the pressing concern of recurrent ED visits among mild influenza patients, magnifying the challenges of ED overcrowding. The observed notable prescription rates of antibiotics and antivirals underscore the intricate landscape of influenza management. Diminished monocyte counts, hemoglobin levels, and altered platelet parameters signify potential markers for identifying patients at risk of recurrent visits.

CD34 Protein: Its expression and function in inflammation

CD34 has spear-headed the field of basic research and clinical transplantation since the first reports of its expression on hematopoietic stem cells (HSCs). Expressed in mice, humans, rats and other species, CD34 has been used for more than 40 years as a hematopoietic stem and progenitor cell marker. It was later found that muscle satellite cells and epidermal precursors can also be identified with the aid of CD34. Despite the usefulness of CD34 as a marker of HSCs, its overall purpose in animal physiology has remained unclear. This review recaptures CD34 structure, evolutionary conservation, proposed functions, and role in lung inflammation, to describe current research findings and to provide guidance for future studies on CD34.

Pathophysiology of Disseminated Intravascular Coagulation in Sepsis: A Clinically Focused Overview

Sepsis is a major global health problem that results from a dysregulated and uncontrolled host response to infection, causing organ failure. Despite effective anti-infective therapy and supportive treatments, the mortality rate of sepsis remains high. Approximately 30-80% of patients with sepsis may develop disseminated intravascular coagulation (DIC), which can double the mortality rate. There is currently no definitive treatment approach for sepsis, with etiologic treatment being the cornerstone of therapy for sepsis-associated DIC. Early detection, diagnosis, and treatment are critical factors that impact the prognosis of sepsis-related DIC. Over the past several decades, researchers have made continuous efforts to better understand the mechanisms of DIC in sepsis, as well as improve its quantitative diagnosis and treatment. This article aims to provide a comprehensive overview of the current understanding of sepsis-related DIC, focusing on common causes and diagnoses, with the goal of guiding healthcare providers in the care of patients with sepsis.

Development and Validation Nomogram for Predicting the Survival of Patients with Thrombocytopenia in Intensive Care Units

Background

The number of patients with thrombocytopenia (TCP) is relatively high in intensive care units (ICUs). It is therefore necessary to evaluate the prognostic risk of such patients.

Aim

This study investigated the risk factors affecting the survival of patients with TCP in the ICU. Using the findings of this investigation, we developed and validated a risk prediction model.

Methods

We evaluated patients admitted to the ICU who presented with TCP. We used LASSO regression to identify important clinical indicators. Based on these indicators, we developed a prediction model complete with a nomogram for the development cohort set. We then evaluated the mode's accuracy using a receiver operating characteristic (ROC) curve, calibration curves, and decision curve analysis (DCA) in a validation cohort.

Results

A total of 141 cases of ICU TCP were included in the sample, of which 47 involved death of the patient. Clinical results were as follows: N (HR 0.91, 95% CI 0.86-0.97, P=0.003); TBIL (HR 1.98, 95% CI 1.02-1.99, P=0.048); APACHE II (HR 1.94, 95% CI 1.39, 2.48, P=0.045); WPRN (HR 6.22, 95% CI 2.86-13.53, P<0.001); WTOST (HR 0.56, 95% CI 0.21-1.46, P<0.001); and DMV [HR1.87, 95% CI 1.12-2.33]. The prediction model yielded an area under the curve (AUC) of 0.918 (95% CI 0.863-0.974) in the development cohort and 0.926 (95% CI 0.849-0.994) in the validation cohort. Application of the nomogram in the validation cohort gave good discrimination (C-index 0.853, 95% CI 0.810-0.922) and good calibration. DCA indicated that the nomogram was clinically useful.

Conclusion

The individualized nomogram developed through our analysis demonstrated effective prognostic prediction for patients with TCP in ICUs. Use of this prediction metric may reduce TCP-related morbidity and mortality in ICUs.

Role of aspirin, beta-blocker, statins, and heparin therapy in septic patients under mechanical ventilation: a narrative review

Sepsis is the main cause of death among patients admitted to intensive care units. Management of sepsis includes fluid resuscitation, vasopressors, intravenous antimicrobials, source control, mechanical ventilation, and others. New insights into the potential benefits of non-antimicrobial drugs in sepsis have evolved based on the pathophysiology of the disease and the mechanism of action of some drugs, but the findings are still controversial. In this study, we aimed to evaluate the effect of beta-blockers, aspirin, statins, and heparin as adjunctive treatments in septic patients under mechanical ventilation with non-cardiovascular diseases and their effect on mortality. We searched PubMed with relevant keywords (beta-blockers, aspirin, statins, or heparin, and critically ill or sepsis) for the last 10 years and some personal collection of relevant articles, and then we assessed studies according to prespecified inclusion and exclusion criteria. Our results show that beta-blockers, aspirin, and heparin may have promising feedback on reducing mortality. However, new well-controlled, randomized, multicenter studies are needed to confirm that, and multiple issues regarding their usage need to be addressed. On the other hand, the feedback regarding the effectiveness of statins was not as strong as that of the other drugs studied, and we suggest that further research is needed to confirm these results.

Potential therapeutic effect of Carica papaya leaves extract on immune response, biochemical and hematological mechanisms on cecal ligation and puncture model of sepsis in rats: an in vivo study

Antibiotics and immunotherapies possess unavoidable adverse effects that hinder sepsis management. Herbal drugs have demonstrated potential immunomodulatory properties vital for sepsis treatment. We hypothesized in the present study that the use of Carica papaya leaves extract had the potential to improve survival and modulate immune cytokine release during sepsis. Animals were subjected to cecal ligation and puncture (CLP) to induce sepsis. Septic rats divided into 10 groups received ethanol extract of C. papaya leaves (50 and 100 mg/kg), imipenem (120 mg/kg) and cyclophosphamide (CP, 10 mg/kg). To investigate the immunomodulatory potentials of EE, cytokine levels like interleukin (IL-6), tumor necrosis factor (TNF-α), and IL-10 along with hematological and biochemical parameters were analyzed. Our results exhibited improved survival rates concerning ethanol extract treatment alone and in combination with imipenem and CP (100%) as compared to the CLP group (33.3%) on day 7 post-surgery. The combination treatment of ethanol extract with imipenem and CP significantly (P < 0.001) ameliorated cytokine levels and hematological and biochemical parameters in septic rats. A histopathological examination suggested improved liver and kidney tissue condition after combination treatment as compared to the CLP group. Therefore, it was concluded that combination therapy of extract with imipenem and CP improved survival rates and marked immunomodulatory potential in septic rats compared to monotherapy. The findings suggested the use of a mixture of these drugs in clinical settings to treat sepsis.

The role of quick Sepsis-related Organ Failure Assessment score as simple scoring system to predict Fournier gangrene mortality and the correlation with Fournier's Gangrene Severity Index: Analysis of 69 patients

Objective

Fournier's gangrene is a rare but life-threatening infection disease with high mortality rate. The quick Sepsis-related Organ Failure Assessment (qSOFA) is a new and simpler scoring system that may identify patients with suspected infection who are at greater risk for a poor outcome. The purpose of this study was to find out role of qSOFA in determining prognosis of Fournier's gangrene patients.

Methods

This study is a case control with retrospective review of Fournier's gangrene patients treated at Hasan Sadikin Hospital from January 2013 to December 2017 who met inclusion criteria. Participants were divided into two groups according to qSOFA score as high qSOFA (2-3) and low qSOFA (0-1).

Results

From 69 patients, the mortality rate was 24.6%. The sensitivity of qSOFA score to predict mortality was 88.2%; the specificity was 94.2%; positive predictive value was 83.3%; negative predictive value was 96.1%; positive likelihood ratio was 15.2; negative likelihood ratio was 0.12; and the area under the receiver operating characteristic curve of qSOFA was 94.2%. There was significant association between qSOFA scale and mortality with p-value of 0.0001. The qSOFA score has strong positive correlation with Fournier's Gangrene Severity Index (p<0.0001, r=0.704).

Conclusion

qSOFA scoring system has a high prognostic value and can be used to determine prognosis of Fournier's gangrene patients.

Platelet‑related parameters as potential biomarkers for the prognosis of sepsis

Early diagnosis and accurate prognosis are key for reducing the fatality rate and medical expenses associated with sepsis. Platelets are involved in the delayed tissue injury that occurs during sepsis. Therefore, the aim of the present study was to investigate the usefulness of platelets and associated parameters as prognostic markers of sepsis. The present study collected patient samples based on The Third International Consensus Definitions for Sepsis and Septic Shock criteria. Platelet-associated parameters were detected by flow cytometry and their correlation with clinical scores and prognoses was analyzed. Considering the association between endothelial cells and platelet activation, levels of plasma tumor necrosis factor-like weak inducer of apoptosis (TWEAK) and angiopoietin-2 (Ang-2) were analyzed by ELISA. The results showed significant differences in platelet P-selectin expression and phosphatidylserine exposure, mitochondrial membrane potential (Mmp)-Index values and plasma levels of TWEAK and Ang-2 between patients and healthy controls (P<0.05). Except for P-selectin and TWEAK levels, all parameters were correlated with clinical scores (acute physiology and chronic health evaluation II and sequential/sepsis-related organ failure assessment). Additionally, platelet Mmp-Index between admission and the end of therapy was only different in non-survivors (P<0.001) and platelet phosphatidylserine exposure was significantly lower in survivors (P=0.006). Therefore, of the parameters tested, the dynamic monitoring of phosphatidylserine exposure, platelet Mmp-Index values and plasma Ang-2 levels had the most potential for the assessment of disease severity and clinical outcomes.

Combining Serum Procalcitonin Level, Thromboelastography, and Platelet Count to Predict Short-term Development of Septic Shock in Intensive Care Unit

OBJECTIVE

Despite the recent advances in diagnosis and treatment, sepsis continues to lead to high morbidity and mortality. Early diagnosis and prompt treatment are essential to save lives. However, most biomarkers can only help to diagnose sepsis, but cannot predict the development of septic shock in high-risk patients. The present study determined whether the combined measurement of procalcitonin (PCT), thromboelastography (TEG) and platelet (PLT) count can predict the development of septic shock.

METHODS

A retrospective study was conducted on 175 septic patients who were admitted to the intensive care unit between January 2017 and February 2021. These patients were divided into two groups: 73 patients who developed septic shock were assigned to the septic shock group, while the remaining 102 patients were assigned to the sepsis group. Then, the demographic, clinical and laboratory data were recorded, and the predictive values of PCT, TEG and PLT count for the development of septic shock were analyzed.

RESULTS

Compared to the sepsis group, the septic shock group had statistically lower PLT count and TEG measurements in the R value, K value, α angle, maximum amplitude, and coagulation index, but had longer prothrombin time (DT), longer activated partial thromboplastin time (APTT), and higher PCT levels. Furthermore, the Sequential Organ Failure Assessment (SOFA) score was higher in the septic shock group. The multivariate logistic regression analysis revealed that PCT, TEG and PLT count were associated with the development of septic shock. The area under the curve analysis revealed that the combined measurement of PCT, TEG and PLT count can be used to predict the development of septic shock with higher accuracy, when compared to individual measurements.

CONCLUSION

The combined measurement of PCT, TEG and PLT count is a novel approach to predict the development of septic shock in high-risk patients.

Effect of antiplatelet agents on Escherichia coli sepsis mechanisms: A review

Despite ever-increasing improvements in the prognosis of sepsis, this condition remains a frequent cause of hospitalization and mortality in Western countries. Sepsis exposes the patient to multiple complications, including thrombotic complications, due to the ability of circulating bacteria to activate platelets. One of the bacteria most frequently implicated in sepsis, Escherichia coli, a Gram-negative bacillus, has been described as being capable of inducing platelet activation during sepsis. However, to date, the mechanisms involved in this activation have not been clearly established, due to their multiple characteristics. Many signaling pathways are thought to be involved. At the same time, reports on the use of antiplatelet agents in sepsis to reduce platelet activation have been published, with variable results. To date, their use in sepsis remains controversial. The aim of this review is to summarize the currently available knowledge on the mechanisms of platelet activation secondary to Escherichia coli sepsis, as well as to provide an update on the effects of antiplatelet agents in these pathological circumstances.

Inhibition of platelet activation suppresses reactive enteric glia and mitigates intestinal barrier dysfunction during sepsis

Background

Intestinal barrier dysfunction, which is associated with reactive enteric glia cells (EGCs), is not only a result of early sepsis but also a cause of multiple organ dysfunction syndrome. Inhibition of platelet activation has been proposed as a potential treatment for septic patients because of its efficacy in ameliorating the organ damage and barrier dysfunction. During platelet activation, CD40L is translocated from α granules to the platelet surface, serving as a biomarker of platelet activation a reliable predictor of sepsis prognosis. Given that more than 95% of the circulating CD40L originate from activated platelets, the present study aimed to investigate if inhibiting platelet activation mitigates intestinal barrier dysfunction is associated with suppressing reactive EGCs and its underlying mechanism.

Methods

Cecal ligation and puncture (CLP) was performed to establish the sepsis model. 24 h after CLP, the proportion of activated platelets, the level of sCD40L, the expression of tight-junction proteins, the intestinal barrier function and histological damage of septic mice were analyzed. In vitro, primary cultured EGCs were stimulated by CD40L and LPS for 24 h and EGCs-conditioned medium were collected for Caco-2 cells treatment. The expression of tight-junction proteins and transepithelial electrical resistance of Caco-2 cell were evaluated.

Results

In vivo, inhibiting platelet activation with cilostazol mitigated the intestinal barrier dysfunction, increased the expression of ZO-1 and occludin and improved the survival rate of septic mice. The efficacy was associated with reduced CD40L⁺ platelets proportion, decreased sCD40L concentration, and suppressed the activation of EGCs. Comparable results were observed upon treatment with compound 6877002, a blocker of CD40L-CD40-TRAF6 signaling pathway. Also, S-nitrosoglutathione supplement reduced intestinal damage both in vivo and in vitro. In addition, CD40L increased release of TNF-α and IL-1β while suppressed the release of S-nitrosoglutathione from EGCs. These EGCs-conditioned medium reduced the expression of ZO-1 and occludin on Caco-2 cells and their transepithelial electrical resistance, which could be reversed by CD40-siRNA and TRAF6-siRNA transfection on EGCs.

Conclusions

The inhibition of platelet activation is related to the suppression of CD40L-CD40-TRAF6 signaling pathway and the reduction of EGCs activation, which promotes intestinal barrier function and survival in sepsis mice. These results might provide a potential therapeutic strategy and a promising target for sepsis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10020-022-00562-w.

Clinical assessment of neutrophil gelatinase-associated lipocalin as a potential diagnostic marker for neonatal sepsis: a prospective cohort study

Sepsis is a life-threatening condition associated with high morbidity and mortality rates among neonates. Clinical diagnosis is limited due to the neonates' unspecific signs and symptoms as well as the long time required to obtain the blood culture results. Consequently, there is an urgent need for new biomarkers to early diagnose neonatal sepsis. We aimed to evaluate Neutrophil Gelatinase-Associated Lipocalin (NGAL) diagnostic performance to detect neonatal sepsis. We enrolled 30 neonates with sepsis admitted to the neonatal intensive care units and 30 age- and sex-matched healthy neonates recruited from the neonatal outpatient clinic during their routine follow-up visits. We measured NGAL levels by sandwich enzyme-linked immunosorbent assay, the C-reactive protein (CRP) with nephelometry technique using BN II nephelometer, and the complete blood count by Mindray BC-6800 analysers. NGAL, CRP, TLC, haemoglobin, and platelet levels showed significant differences between cases and control (all p < .001). Of the 30 neonates with sepsis, 17 neonates (56.7%) survived. At 0 h, the NGAL level showed no statistically significant difference between the non-survivors and survivors' groups; however, after 96 h, NGAL was significantly higher in the non-survivors group (p ˂ .001). Our diagnostic analysis showed that NGAL levels have strong discrimination power to early differentiate neonates with sepsis; at the 475.00 pg/ml cut-off value, NGAL showed both sensitivity and specificity of 100% with an area under curve of 100%. Conclusion: Our study suggests that NGAL could be a promising biomarker for neonatal sepsis detection. Further studies with larger sample sizes and survival analysis are warranted to confirm this finding and to clarify the efficacy of NGAL in survival prediction. Key findingsNGAL level was high in neonates with sepsisNGAL level was high in non-survived neonatesNGAL could be a promising diagnostic marker for sepsis.

Inhibition of platelet activation suppresses reactive enteric glia and mitigates intestinal barrier dysfunction during sepsis

Background

Intestinal barrier dysfunction, which is associated with reactive enteric glia cells (EGCs), is not only a result of early sepsis but also a cause of multiple organ dysfunction syndrome. Inhibition of platelet activation has been proposed as a potential treatment for septic patients because of its efficacy in ameliorating the organ damage and barrier dysfunction. During platelet activation, CD40L is translocated from α granules to the platelet surface, serving as a biomarker of platelet activation a reliable predictor of sepsis prognosis. Given that more than 95% of the circulating CD40L originate from activated platelets, the present study aimed to investigate if inhibiting platelet activation mitigates intestinal barrier dysfunction is associated with suppressing reactive EGCs and its underlying mechanism.

Methods

Cecal ligation and puncture (CLP) was performed to establish the sepsis model. 24 h after CLP, the proportion of activated platelets, the level of sCD40L, the expression of tight-junction proteins, the intestinal barrier function and histological damage of septic mice were analyzed. In vitro, primary cultured EGCs were stimulated by CD40L and LPS for 24 h and EGCs-conditioned medium were collected for Caco-2 cells treatment. The expression of tight-junction proteins and transepithelial electrical resistance of Caco-2 cell were evaluated.

Results

In vivo, inhibiting platelet activation with cilostazol mitigated the intestinal barrier dysfunction, increased the expression of ZO-1 and occludin and improved the survival rate of septic mice. The efficacy was associated with reduced CD40L⁺ platelets proportion, decreased sCD40L concentration, and suppressed the activation of EGCs. Comparable results were observed upon treatment with compound 6,877,002, a blocker of CD40L–CD40–TRAF6 signaling pathway. Also, S-nitrosoglutathione supplement reduced intestinal damage both in vivo and in vitro. In addition, CD40L increased release of TNF-α and IL-1β while suppressed the release of S-nitrosoglutathione from EGCs. These EGCs-conditioned medium reduced the expression of ZO-1 and occludin on Caco-2 cells and their transepithelial electrical resistance, which could be reversed by CD40-siRNA and TRAF6-siRNA transfection on EGCs.

Conclusions

The inhibition of platelet activation is related to the suppression of CD40L-CD40-TRAF6 signaling pathway and the reduction of EGCs activation, which promotes intestinal barrier function and survival in sepsis mice. These results might provide a potential therapeutic strategy and a promising target for sepsis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10020-022-00556-8.

Neutrophil-lymphocyte ratio and platelet-lymphocyte ratio use in detecting bowel ischaemia in adhesional small bowel obstruction

BACKGROUND

Bowel ischaemia significantly increases morbidity and mortality from adhesional small bowel obstruction. Current biomarkers and clinical parameters have poor predictive value for ischaemia. Our study investigated whether neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) could be used to predict bowel ischaemia in adhesional small bowel obstruction.

METHODS

This single-centre retrospective study collected clinical, biochemical and radiological data from patients with adhesional small bowel obstruction between 2017 and 2020 who underwent operative management. The presence or absence of bowel ischaemia/infarction was used to distinguish two populations. Biochemical markers on admission and immediately prior to operation were collected to give platelet-lymphocyte ratio (PLR₀ and PLR_PRE-OP , respectively) and neutrophil-lymphocyte ratio (NLR₀ and NLR_PRE-OP , respectively). SAS 9.4 (SAS Institute Inc., Cary, NC) software was used for data analysis with Mann-Whitney U testing for continuous variables and Pearson Chi-square test for categorical variables. Sensitivity and specificity for PLR and NLR were calculated by means of receiver operating characteristic (ROC) curve analysis.

RESULTS

Twenty-seven patients had intra-operative bowel ischaemia whilst the remaining 73 had no evidence of bowel ischaemia. Both median PLR_PRE-OP and NLR_PRE-OP were significantly higher in patients with bowel ischaemia compared to those without (PLR_PRE-OP 272 [IQR 224-433] and 231 [IQR 146-295] respectively, P = 0.027; NLR_PRE-OP 12.5 [IQR 8.6-21.3] v. 5.5 [IQR 3.5-10.2] respectively, P ≤ 0.001). Area under the receiver operator characteristic curve (AUC) was 0.762 for NLR_PRE-OP , with a sensitivity of 85.1% and specificity of 63% for NLR 7.4.

CONCLUSION

Raised NLR is predictive of bowel ischaemia in patients with adhesional small bowel obstruction.

ICU and Sepsis: Role of Myeloid and Lymphocyte Immune Cells

Sepsis is a severe immune system reaction to infection and a major cause of ICU-related fatalities. Because of the high mortality, high cost of treatment, and complex aetiology of sepsis, sepsis has a huge impact on healthcare. Some of the health complications in sepsis are abnormal cardiac functions, hypoperfusion, hypotension, tissue damage, multiple organ failure, and ultimately death. Individuals with weak immune systems and chronic medical conditions are highly vulnerable to sepsis. In sepsis, a patient shows the extreme immune response in the initial stage while prolonged immunosuppression in the later stages. Sepsis-driven immunosuppression ushers in death because sepsis cases develop secondary infections postrecovery. The later immunocompromised state in sepsis is attributed myeloid-derived suppressor cell upregulation and reduced immune activity displayed by lymphocytes (lymphocyte anergy). As a result, it is currently suggested that regulating the immune response is a better therapeutic approach than focusing on inflammation to improve the immune system's capacity to fight infections. Moreover, finding novel and accurate prognostic biomarkers that can help in rapid sepsis diagnoses and deciding better therapeutic strategies will significantly lower clinical case mortality rates.

The Controversial Role of LPS in Platelet Activation In Vitro

Circulating platelets are responsible for hemostasis and thrombosis but are also primary sensors of pathogens and are involved in innate immunity, inflammation, and sepsis. Sepsis is commonly caused by an exaggerated immune response to bacterial, viral, and fungal infections, and leads to severe thrombotic complications. Among others, the endotoxin lipopolysaccharide (LPS) found in the outer membrane of Gram-negative bacteria is the most common trigger of sepsis. Since the discovery of the expression of the LPS receptor TLR4 in platelets, several studies have investigated the ability of LPS to induce platelet activation and to contribute to a prothrombotic phenotype, per se or in combination with plasma proteins and platelet agonists. This issue, however, is still controversial, as different sources, purity, and concentrations of LPS, different platelet-purification protocols, and different methods of analysis have been used in the past two decades, giving contradictory results. This review summarizes and critically analyzes past and recent publications about LPS-induced platelet activation in vitro. A methodological section illustrates the principal platelet preparation protocols and significant differences. The ability of various sources of LPS to elicit platelet activation in terms of aggregation, granule secretion, cytokine release, ROS production, and interaction with leukocytes and NET formation is discussed.

Thrombocytopenia and Bloodstream Infection: Incidence and Implication on Length of Stay in the Pediatric Intensive Care Unit

The incidence and prognosis of thrombocytopenia in critically ill patients with bloodstream infection (BSI) is not well delineated in the pediatric intensive care unit (PICU) setting. We assessed these variables in our PICU and sought to determine whether thrombocytopenia could serve as a prognostic marker for length of stay (LOS). The study was conducted at the medical PICU of a university hospital, on all critically ill pediatric patients consecutively admitted during a 3-year period. Patient surveillance and data collection have been used to identify the risk factors during the study period. The main outcomes were BSI incidence and implication on morbidity and LOS. Data from 2,349 PICU patients was analyzed. The overall incidence of BSI was 3.9% (93/2,349). Overall, 85 of 93 patients (91.4%) with BSI survived and 8 patients died (8.6% mortality rate). The overall incidence of thrombocytopenia among these 93 patients was 54.8% (51/93) and 100% (8/8) for the nonsurvivors. Out of the 85 survivors, 27 thrombocytopenic patients were hospitalized for >14 days versus 14 of nonthrombocytopenic patients (p = 0.007). Thrombocytopenia was associated with borderline significance with an increased LOS (adjusted odds ratio = 3.00, 95% confidence interval: 0.93–9.71, p = 0.066). Thrombocytopenia is common in critically ill pediatric patients with BSI and constitutes a simple and readily available risk marker for PICU LOS.

Modes of action and diagnostic value of miRNAs in sepsis

Sepsis is a clinical syndrome defined as a dysregulated host response to infection resulting in life-threatening organ dysfunction. Sepsis is a major public health concern associated with one in five deaths worldwide. Sepsis is characterized by unbalanced inflammation and profound and sustained immunosuppression, increasing patient susceptibility to secondary infections and mortality. microRNAs (miRNAs) play a central role in the control of many biological processes, and deregulation of their expression has been linked to the development of oncological, cardiovascular, neurodegenerative and metabolic diseases. In this review, we discuss the role of miRNAs in sepsis pathophysiology. Overall, miRNAs are seen as promising biomarkers, and it has been proposed to develop miRNA-based therapies for sepsis. Yet, the picture is not so straightforward because of the versatile and dynamic features of miRNAs. Clearly, more research is needed to clarify the expression and role of miRNAs in sepsis, and to promote the use of miRNAs for sepsis management.

An Insight into Recent Advances on Platelet Function in Health and Disease

Platelets play a variety of roles in vascular biology and are best recognized as primary hemostasis and thrombosis mediators. Platelets have a large number of receptors and secretory molecules that are required for platelet functionality. Upon activation, platelets release multiple substances that have the ability to influence both physiological and pathophysiological processes including inflammation, tissue regeneration and repair, cancer progression, and spreading. The involvement of platelets in the progression and seriousness of a variety of disorders other than thrombosis is still being discovered, especially in the areas of inflammation and the immunological response. This review represents an integrated summary of recent advances on the function of platelets in pathophysiology that connects hemostasis, inflammation, and immunological response in health and disease and suggests that antiplatelet treatment might be used for more than only thrombosis.

Correlation between thrombopoietin and inflammatory factors, platelet indices, and thrombosis in patients with sepsis: A retrospective study

BACKGROUND

Thrombopoietin (TPO) is a primary regulator of thrombopoiesis in physiological conditions. TPO, in combination with its specific cytokine receptor c-Mpl, drives platelet production by inducing the proliferation and differentiation of megakaryocytes. However, the role of TPO in sepsis is not well determined. The elevated levels of TPO are often accompanied by a decrease of platelet count (PLT) in systemic infected conditions, which is contrary to the view that TPO promotes platelet production under physiological conditions. In addition, whether TPO mediates organ damage in sepsis remains controversial.

AIM

To explore the relationships between TPO and inflammatory factors, platelet indices, and thrombotic indicators in sepsis.

METHODS

A total of 90 patients with sepsis diagnosed and treated at the emergency medicine department of The First People’s Hospital of Foshan between January 2020 and March 2021 were enrolled in this study. In addition, 110 patients without sepsis who came to the emergency medicine department were included as controls. Clinical and laboratory parameters including age, gender, TPO, blood cell count in peripheral blood, platelet indices, inflammatory factors such as high-sensitivity C-reactive protein (hs-CRP), interleukin (IL)-21, and IL-6, organ damage indicators, and thrombotic indicators were collected and analyzed by using various statistical approaches.

RESULTS

The results showed that the TPO levels were higher in the sepsis group than in controls [86.45 (30.55, 193.1) vs 12.45 (0.64, 46.09) pg/mL, P < 0.001], but PLT was lower (P < 0.001). Multivariable analysis showed that white blood cell count (WBC) [odds ratio (OR) = 1.32; 95% confidence interval (CI): 1.01-1.722; P = 0.044], TPO (OR = 1.02; 95%CI: 1.01-1.04; P = 0.009), IL-21 (OR = 1.02; 95%CI: 1.00-1.03; P = 0.019), troponin I (OR = 55.20; 95%CI: 5.69-535.90; P = 0.001), and prothrombin time (PT) (OR = 2.24; 95%CI: 1.10-4.55; P = 0.027) were independent risk factors associated with sepsis. TPO levels were positively correlated with IL-21, IL-6, hs-CRP, creatinine, D-dimer, PT, activated prothrombin time, international normalized ratio, fibrinogen, WBC count, and neutrophil count, and negatively correlated with PLT, thrombin time, red blood cell count, and hemoglobin concentration (P < 0.05). Receiver operating characteristic analysis showed that TPO had fair predictive value in distinguishing septic patients and non-septic patients (the area under the curve: 0.788; 95%CI: 0.723-0.852; P < 0.001). With an optimized cutoff value (28.51 pg/mL), TPO had the highest sensitivity (79%) and specificity (65%).

CONCLUSION

TPO levels are independently associated with sepsis. High TPO levels and low PLT suggest that TPO might be an acute-phase response protein in patients with infection.

Prognostic Role of Subsequent Thrombocytopenia in Necrotizing Fasciitis Without Liver Disease

BACKGROUND

Necrotizing fasciitis (NF) is a life-threatening disease with a fulminant presentation. Although early diagnosis can be aided by combining physical examination, the Laboratory Risk Indicator for Necrotizing Fasciitis score, and computed tomography, a mortality rate of 30% is still reported. In the modern times, an economical and efficient biomarker for predicting mortality in NF patients is still lacking. Platelet count is typically measured in routine blood tests and aids in predicting disease severity. We aimed to clarify the role of platelet count as a predictive factor for aspects of prognosis, such as mortality and surgical outcomes, in patients with NF.

METHODS

We identified 285 patients with NF between 2018 and 2020 in a single medical center in southern Taiwan. Medical records were collected for the evaluation of patients with thrombocytopenia. Univariate and multivariate analyses were performed for different outcomes.

RESULTS

We included 115 patients with confirmed diagnoses of NF. Twelve patients died with a mortality rate of 10.4%. Patients with thrombocytopenia exhibited a higher mortality rate (20.9% vs 4.2%, P = 0.006), more shock episodes (51.2% vs 11.1%, P < 0.001), higher intensive care unit admission rate (46.5% vs 13.9%, P < 0.001), and longer hospital length of stay (37.49 ± 24.12 days vs 28.82 ± 14.63 days, P = 0.037) than those without thrombocytopenia. All patients infected with Vibrio species exhibited thrombocytopenia. In multivariate analysis, independent risk factors for mortality were thrombocytopenia (odds ratio, 4.57; 95% confidence interval, 1.08-19.25) and single gram-negative bacterial culture from the wound (odds ratio 6.88; 95% confidence interval, 1.58-29.96).

CONCLUSIONS

In patients with NF and subsequent thrombocytopenia, a higher mortality rate, greater numbers of shock episodes, higher demand for intensive care unit, and longer hospital length of stay were observed than in those without thrombocytopenia. In patients with NF, platelet count is a valuable and economic indicator of prognosis. Once thrombocytopenia developed in patients with necrotizing fasciitis, aggressive antibiotic treatment and surgical management are required to improve the chances of recovery.

The Underestimated Role of Platelets in Severe Infection a Narrative Review

Beyond their role in hemostasis, platelets have emerged as key contributors in the immune response; accordingly, the occurrence of thrombocytopenia during sepsis/septic shock is a well-known risk factor of mortality and a marker of disease severity. Recently, some studies elucidated that the response of platelets to infections goes beyond a simple fall in platelets count; indeed, sepsis-induced thrombocytopenia can be associated with—or even anticipated by—several changes, including an altered morphological pattern, receptor expression and aggregation. Of note, alterations in platelet function and morphology can occur even with a normal platelet count and can modify, depending on the nature of the pathogen, the pattern of host response and the severity of the infection. The purpose of this review is to give an overview on the pathophysiological interaction between platelets and pathogens, as well as the clinical consequences of platelet dysregulation. Furthermore, we try to clarify how understanding the nature of platelet dysregulation may help to optimize the therapeutic approach.

TSST-1 protein exerts indirect effect on platelet activation and apoptosis

Thrombocytopenia or platelet dysfunction is a risk factor for severe infection. Staphylococcus aureus (S. aureus) releases a variety of virulence factors especially toxic shock syndrome toxin 1 (TSST-1), which may cause toxic shock syndrome. S. aureus, when carrying the tst gene, is more prone to cause toxic shock syndrome and is responsible for an especially high rate of mortality. However, the effect of TSST-1 protein on platelets is unknown. Patients with the tst gene positive S. aureus bacteremia showed more serious infection, higher mortality and lower platelet count. The tst gene positive S. aureus strains induce more platelet apoptosis and activation and corresponding up-regulation of Bak and down-regulation of Bcl-XL in addition to the activation of Caspase-3. C57BL/6 mice infected with the tst gene positive strains resulted in both a decrease in platelet count and an increase in platelet apoptosis and/or activation events and mortality. Moreover, TSST-1 protein, encoded by tst gene, caused the decrease of platelet count, the increase of platelet apoptosis and activation events and the level of inflammatory cytokines in vivo. However, TSST-1 protein was unable to induce traditional activation and apoptosis on human platelets in vitro. These results suggested that TSST-1 protein may exert indirect effects on platelet activation and apoptosis in vivo.

Clotting Dysfunction in Sepsis: A Role for ROS and Potential for Therapeutic Intervention

Sepsis is regarded as one of the main causes of death among the critically ill. Pathogen infection results in a host-mediated pro-inflammatory response to fight infection; as part of this response, significant endogenous reactive oxygen (ROS) and nitrogen species (RNS) production occurs, instigated by a variety of sources, including activated inflammatory cells, such as neutrophils, platelets, and cells from the vascular endothelium. Inflammation can become an inappropriate self-sustaining and expansive process, resulting in sepsis. Patients with sepsis often exhibit loss of aspects of normal vascular homeostatic control, resulting in abnormal coagulation events and the development of disseminated intravascular coagulation. Diagnosis and treatment of sepsis remain a significant challenge for healthcare providers globally. Targeting the drivers of excessive oxidative/nitrosative stress using antioxidant treatments might be a therapeutic option. This review focuses on the association between excessive oxidative/nitrosative stress, a common feature in sepsis, and loss of homeostatic control at the level of the vasculature. The literature relating to potential antioxidants is also described.

Endothelial dysfunction caused by circulating microparticles from diabetic mice is reduced by PD98059 through ERK and ICAM-1

Endothelial dysfunction contributes to the development of diabetic complications and the production of circulating microparticles (MPs). Our previous study showed that diabetic mice-derived MPs (DM MPs) had increased levels of extracellular regulated protein kinase 1/2 (ERK1/2) and impaired endothelial-dependent relaxation in aortas when compared with control mice-derived MPs. This study was designed to investigate whether PD98059, an ERK1/2 inhibitor, affects the function of aortas and DM MPs. MPs were obtained from streptozotocin-induced DM, DM after PD98059 treatment, and ICR mice as control. The mice and MPs were then analyzed on the basis of their vascular function and enzyme expressions. Compared with the controls, platelet-derived MPs and ERK1/2 levels in the MPs were significantly elevated in the DM but showed little change in PD98059-treated DM. PD98059 mainly decreased ERK1/2 phosphorylation in the MPs. In the aortas of DM and DM MPs the endothelium-dependent vascular function was impaired, and there was a significantly greater improvement in the vascular function in the PD98059-treated DM aortas and the aortas treated with PD98059-treated DM MPs than in DM aortas and the aortas treated with DM MPs. Furthermore, DM MPs increased ERK1/2 and intracellular adhesion molecule-1 (ICAM-1) expressions in the aortas, but PD98059-treated DM MPs did not show these effects. For the first time, these results indicate that PD98059 treatment improves endothelial dysfunction in DM, and adhesion properties of DM MPs can be partly blocked by PD98059 via ERK and ICAM-1. These effects may explain some of the vascular complications in diabetes.

[Acute kidney injury in intensive care unit: A review]

Acute kidney injury is a common complication in intensive care unit. Its incidence is variable according to the studies. It is considered to occur in more than 50 % of patients. Acute kidney injury is responsible for an increase in morbidity (length of hospitalization, renal replacement therapy) but also for excess mortality. The commonly accepted definition of acute kidney injury comes from the collaborative workgroup named Kidney Disease: Improving Global Outcomes (KDIGO). It made it possible to standardize practices and raise awareness among practitioners about monitoring plasma creatinine and also diuresis. Acute kidney injury in intensive care unit is a systemic disease including circulatory, endothelial, epithelial and cellular function involvement and an acute kidney injury is not accompanied by ad integrum repair. After prolonged injury, inadequate repair begins with a fibrotic process. Several mechanisms are involved (cell cycle arrest, epithelial-mesenchymal transition, mitochondrial dysfunction) and result in improper repair. A continuum exists between acute kidney disease and chronic kidney disease, characterized by different renal recovery phenotypes. Thus, preventive measures to prevent the occurrence of kidney damage play a major role in management. The nephrologist must be involved at every stage, from the prevention of the first acute kidney injury (upon arrival in intensive care unit) to long-term follow-up and the care of a chronic kidney disease.

Long-term cardiovascular complications following sepsis: is senescence the missing link?

Among the long-term consequences of sepsis (also termed “post-sepsis syndrome”) the increased risk of unexplained cardiovascular complications, such as myocardial infarction, acute heart failure or stroke, is one of the emerging specific health concerns. The vascular accelerated ageing also named premature senescence is a potential mechanism contributing to atherothrombosis, consequently leading to cardiovascular events. Indeed, vascular senescence-associated major adverse cardiovascular events (MACE) are a potential feature in sepsis survivors and of the elderly at cardiovascular risk. In these patients, accelerated vascular senescence could be one of the potential facilitating mechanisms. This review will focus on premature senescence in sepsis regardless of age. It will highlight and refine the potential relationships between sepsis and accelerated vascular senescence. In particular, key cellular mechanisms contributing to cardiovascular events in post-sepsis syndrome will be highlighted, and potential therapeutic strategies to reduce the cardiovascular risk will be further discussed.

With improved management of patients, sepsis survivors are increasing each year.

Early cardiovascular complications, of yet undeciphered mechanisms, are an emerging health issue in post-sepsis syndrome.

Premature senescence of endothelium and vascular tissue is proven an accelerated process of atherogenesis in young septic rats.

An increasing body of clinical evidence point at endothelial senescence in the initiation and development of atherosclerosis.

Prevention of premature senescence by senotherapy and cardiological follow-up could improve long-term septic patients’ outcomes.

Serum markers for the early diagnosis of intestinal anastomotic leak after gyne-oncological operations

OBJECTIVE

To analyse the serum markers for the early diagnosis of intestinal anastomotic leak (AL) after the gyne-oncological operations.

METHODS

Between September 2017 and March 2021, patients with an intestinal anastomosis performed during the gyne-oncological surgeries were identified from a tertiary centre in Turkey. As the local guideline of the clinic, all these patients were followed by measuring serum samples including procalcitonin (PCT) and C-reactive protein (CRP) on postoperative day (POD) 1 through the day of discharge or the day of re-operation for AL.

RESULTS

12.5% (5/40) of the patients suffered an AL and 4 of them were re-operated. The mean albumin values on POD 3-4 and the mean platelet values on POD 1 were lower in the AL group (P < .05). Although it was not statistically significant (P > .05), median PCT values (ng/mL) on POD 8-10 were higher in the AL group compared with no leak group. The best cut-off point for PCT on POD 9 was determined to be 0.11 ng/mL (AUC: 0.917, Sensitivity = 100.0%, specificity = 66.7%, positive predictive value = 66.7%, negative predictive value = 100.0%).

CONCLUSION

Serum PCT and CRP concentrations were not found to be helpful for the early diagnosis of AL in patients operated for gyne-oncological malignancies. Low levels of albumin and platelets in the first days after the operation may be clue for a possible AL.

Potential role of herbal medicines as a novel approach in sepsis treatment

The growing number of deaths related to sepsis has become a major concern for past few years. Sepsis is a complex pathological reactions that is explained by series of host response to microbial insult. The resulted systemic reactions are manifested by early appearance of proinflammatory cytokines leading to hyperinflammatory phase which is followed by septic shock and death of the patient. The present study has revealed that antibiotics are not self-sufficient to control the complex mechanism of sepsis. Moreover prolonged and unnecessary administration of antibiotics may lead to antibiotic resistance to pathogens. In addition to this, immunosuppressive medications are selective and have targeted approach to certain study population. Drugs from herbal origin have shown to possess a mammoth of immunomodulatory potential by suppressing proinflammatory and anti-inflammatory cytokines exhibiting no or minimal unwanted secondary responses. Concomitantly, herbal plants tend to modulate oxidative stress level and haematological imbalance during inflammatory diseased conditions. Natural compounds have gained much attention for the treatment of several clinical complications. Considering the promising responses of medicinal plants with less/no side effects and easy procurement, comprehensive research on herbal plants to treat sepsis should be contemplated.

The Value of a Complete Blood Count (CBC) for Sepsis Diagnosis and Prognosis

Sepsis represents an important global health burden due to its high mortality and morbidity. The rapid detection of sepsis is crucial in order to prevent adverse outcomes and reduce mortality. However, the diagnosis of sepsis is still challenging and many efforts have been made to identify reliable biomarkers. Unfortunately, many investigated biomarkers have several limitations that do not support their introduction in clinical practice, such as moderate diagnostic and prognostic accuracy, long turn-around time, and high-costs. Complete blood count represents instead a precious test that provides a wealth of information on individual health status. It can guide clinicians to early-identify patients at high risk of developing sepsis and to predict adverse outcomes. It has several advantages, being cheap, easy-to-perform, and available in all wards, from the emergency department to the intensive care unit. Noteworthy, it represents a first-level test and an alteration of its parameters must always be considered within the clinical context, and the eventual suspect of sepsis must be confirmed by more specific investigations. In this review, we describe the usefulness of basic and new complete blood count parameters as diagnostic and prognostic biomarkers of sepsis.

Association between platelet count and multiorgan dysfunction and outcomes in patients with sepsis in the pediatric intensive care unit in Saudi Arabia

BACKGROUND

Sepsis is one of the leading causes of morbidity and mortality in the pediatric population worldwide. This study aimed to establish a correlation between platelet count and outcomes of severe sepsis/septic shock in pediatric patients.

METHODS

This retrospective cohort study was conducted in the pediatric intensive care unit (PICU) in a pediatric tertiary care medical hospital. Pediatric patients from newborns to 14-year-olds with a diagnosis of sepsis or septic shock who were admitted to the PICU between April 2015 and February 2018 were enrolled. Patients were classified into two groups based on the presence of thrombocytopenia: thrombocytopenia group (TG) with a platelet count <150,000/μL during the first seven days after admission, and non-thrombocytopenia group (NTG) with a platelet count >150,000/μL.

RESULTS

Overall, 206 children were enrolled, including 82 (39.8%) in the TG and 124 (60.2%) in the NTG. Thrombocytopenia was more common in patients with a negative bacterial blood culture (93.9%, P = 0.007). NTG was associated with a higher mortality rate (29%) than the TG (12.2%, P = 0.005). Multiorgan dysfunction syndrome (MODS) at the onset of sepsis (time zero) was found to be more prevalent in NTG than in TG (P = 0.001), while the progression of MODS over the three days remained the same in both groups.

CONCLUSION

Thrombocytopenia was more associated with non-bacterial sepsis/septic shock, and it may indicate a better outcome of sepsis in pediatric patients.

The pathophysiology of sepsis-2021 update: Part 1, immunology and coagulopathy leading to endothelial injury

Disclaimer

In an effort to expedite the publication of articles related to the COVID-19 pandemic, AJHP is posting these manuscripts online as soon as possible after acceptance. Accepted manuscripts have been peer-reviewed and copyedited, but are posted online before technical formatting and author proofing. These manuscripts are not the final version of record and will be replaced with the final article (formatted per AJHP style and proofed by the authors) at a later time.

Purpose

To provide an overview of current literature on the pathophysiology of sepsis, with a focus on mediators of endothelial injury and organ dysfunction.

Summary

Sepsis is a dysregulated response to infection that triggers cascades of interconnected systems. Sepsis has been a significant cause of mortality worldwide, and the recent viral pandemic that may produce severe sepsis and septic shock has been a major contributor to sepsis-related mortality. Understanding of the pathophysiology of sepsis has changed dramatically over the last several decades. Significant insight into the components of the inflammatory response that contribute to endothelial injury and trigger coagulation pathways has been achieved. Similarly, characterization of anti-inflammatory pathways that may lead to secondary infections and poor outcome has illustrated opportunities for improved therapies. Description of an increasing number of important mediators and pathways has occurred and may point the way to novel therapies to address immune dysregulation. Pharmacists will need a fundamental understanding of the overlapping pathways of the immune response to fully prepare for use of novel treatment options. While pharmacists typically understand coagulation cascade how to utilize anticoagulants, the issues in sepsis related coagulopathy and role of mediators such as cytokines and complement and role of activated platelets and neutrophils require a different perspective.

Conclusion

Pharmacists can benefit from understanding both the cellular and organ system issues in sepsis to facilitate assessment of potential therapies for risk and benefit.

Serum C1q Levels Have Prognostic Value for Sepsis and are Related to the Severity of Sepsis and Organ Damage

Objective

To explore the clinical application value of serum complement component C1q levels in sepsis.

Methods

The clinical data and laboratory examination data of 320 research subjects (including 132 cases as sepsis group, 93 cases as nonsepsis group and 95 cases as control group) who were diagnosed and treated in Renmin Hospital of Wuhan University from July 2020 to March 2021 were collected. We compared the levels of each index among the three groups and further analyzed the C1q levels of different severity subgroups and different outcome subgroups of sepsis. Afterwards, we explored the correlation between C1q levels and SOFA score, organ damage indexes and coagulation indexes. Finally, the receiver operating characteristic curve (ROC) was used to analyze the prognostic value of C1q in patients with sepsis.

Results

C1q levels were significantly reduced in the serum of patients with sepsis; the level of C1q in the death group was lower than that in the survival group (127.1 mg/L vs 153.2 mg/L, P < 0.05), and the mortality in the C1q decreased group was higher when compared with C1q normal group; in addition, serum C1q levels were correlated with SOFA score, organ damage indexes and coagulation indexes; C1q had a high area under the curve (AUC) for the prognosis of sepsis, and the combination of other indexes can further improve the prognostic value.

Conclusion

Serum C1q levels have potential clinical value for the condition and prognosis of sepsis.

Platelet activation in critically ill COVID-19 patients

BACKGROUND

Microvascular, arterial and venous thrombotic events have been largely described during severe coronavirus disease 19 (COVID-19). However, mechanisms underlying hemostasis dysregulation remain unclear.

METHODS

We explored two independent cross-sectional cohorts to identify soluble markers and gene-expression signatures that discriminated COVID-19 severity and outcomes.

RESULTS

We found that elevated soluble (s)P-selectin at admission was associated with disease severity. Elevated sP-selectin was predictive of intubation and death (ROC AUC = 0.67, p = 0.028 and AUC = 0.74, p = 0.0047, respectively). An optimal cutoff value was predictive of intubation with 66% negative predictive value (NPV) and 61% positive predictive value (PPV), and of death with 90% NPV and 55% PPV. An unbiased gene set enrichment analysis revealed that critically ill patients had increased expression of genes related to platelet activation. Hierarchical clustering identified ITG2AB, GP1BB, PPBP and SELPLG to be upregulated in a grade-dependent manner. ROC curve analysis for the prediction of intubation was significant for SELPLG and PPBP (AUC = 0.8, p = 0.046 for both). An optimal cutoff value for PBPP was predictive of intubation with 100% NPV and 45% PPV, and for SELPLG with 100% NPV and 50% PPV.

CONCLUSION

We provide evidence that platelets contribute to COVID-19 severity. Plasma sP-selectin level was associated with severity and in-hospital mortality. Transcriptional analysis identified PPBP/CXCL7 and SELPLG as biomarkers for intubation. These findings provide additional evidence for platelet activation in driving critical COVID-19. Specific studies evaluating the performance of these biomarkers are required.

Selenocompounds and Sepsis: Redox Bypass Hypothesis for Early Diagnosis and Treatment: Part A-Early Acute Phase of Sepsis: An Extraordinary Redox Situation (Leukocyte/Endothelium Interaction Leading to Endothelial Damage)

Significance: Sepsis is a health disaster. In sepsis, an initial, beneficial local immune response against infection evolves rapidly into a generalized, dysregulated response or a state of chaos, leading to multiple organ failure. Use of life-sustaining supportive therapies creates an unnatural condition, enabling the complex cascades of the sepsis response to develop in patients who would otherwise die. Multiple attempts to control sepsis at an early stage have been unsuccessful. Recent Advances: Major events in early sepsis include activation and binding of leukocytes and endothelial cells in the microcirculation, damage of the endothelial surface layer (ESL), and a decrease in the plasma concentration of the antioxidant enzyme, selenoprotein-P. These events induce an increase in intracellular redox potential and lymphocyte apoptosis, whereas apoptosis is delayed in monocytes and neutrophils. They also induce endothelial mitochondrial and cell damage. Critical Issues: Neutrophil production increases dramatically, and aggressive immature forms are released. Leukocyte cross talk with other leukocytes and with damaged endothelial cells amplifies the inflammatory response. The release of large quantities of reactive oxygen, halogen, and nitrogen species as a result of the leukocyte respiratory burst, endothelial mitochondrial damage, and ischemia/reperfusion processes, along with the marked decrease in selenoprotein-P concentrations, leads to peroxynitrite damage of the ESL, reducing flow and damaging the endothelial barrier. Future Directions: Endothelial barrier damage by activated leukocytes is a time-sensitive event in sepsis, occurring within hours and representing the first step toward organ failure and death. Reducing or stopping this event is necessary before irreversible damage occurs.

Research Advances in the Subtype of Sepsis-Associated Thrombocytopenia

The incidence and mortality of sepsis in the intensive care unit (ICU) are extremely high. Thrombocytopenia, one of the most common laboratory abnormalities, is correlated with prognosis in sepsis. The pathophysiology of sepsis-associated thrombocytopenia (SAT) remains unclear and may be associated with several factors such as platelet activation due to vascular injury and pathogen, suppression of bone marrow, platelet-targeted antibodies and desialylation. This review summarized all these possible mechanisms in the 3 subtypes of SAT: increased platelet consumption, reduced platelet production and increased platelet destruction. Based on the clinically available platelet parameters, the evidence for identifying SAT subtypes and the recent progress in treatments according to these subtypes are proposed to provide new prospects for the management of SAT.

Evaluation of leukopenia during sepsis as a marker of sepsis-defining organ dysfunction

Background

Although both leukocytosis and leukopenia have been considered Systemic Inflammatory Response Syndrome criteria, leukopenia is not generally considered a normal response to infection. We sought to evaluate the prognostic validity of leukopenia as a sign of sepsis-defining hematological organ dysfunction within the Sepsis-3 framework. We hypothesized that leukopenia is associated with higher risk of mortality than leukocytosis among patients with suspected infection.

Methods

We performed a retrospective cohort study using the Medical Information Mart v1.4 in Intensive Care-III database. Multivariable regression models were used to evaluate the association between leukopenia and mortality in patients with suspected infection defined by Sepsis-3.

Results

We identified 5,909 ICU patients with suspected infection; 250 (4.2%) had leukopenia. Leukopenia was associated with increased in-hospital mortality compared with leukocytosis (OR, 1.5; 95% CI 1.1–1.9). After adjusting for demographics and comorbidities in the Sepsis-3 consensus model, leukopenia remained associated with increased risk of mortality compared with leukocytosis (OR 1.6, 95% CI 1.2–2.2). Further adjustment for the platelet component of the SOFA attenuated the association between leukopenia and mortality (OR decreased from 1.5 to 1.1). However, 83 (1.4%) of patients had leukopenia without thrombocytopenia and 14 had leukopenia prior to thrombocytopenia.

Conclusions

Among ICU patients with suspected infection, leukopenia was associated with increased risk of death compared with leukocytosis. Due to correlation with thrombocytopenia, leukopenia did not independently improve the prognostic validity of SOFA; however, leukopenia may present as a sign of sepsis prior to thrombocytopenia in a small subset of patients.

Multi-Organ Transcriptome Dynamics in a Mouse Model of Cecal Ligation and Puncture-Induced Polymicrobial Sepsis

PURPOSE

During sepsis, an excessive inflammatory immune reaction contributes to multi-organ dysfunction syndrome (MODS), a critical condition associated with high morbidity and mortality; however, the molecular mechanisms driving MODS remain elusive.

METHODS

We used RNA sequencing to characterize transcriptional changes in the early phase of sepsis, at 6, 12, 24 hour time points in lung, kidney, liver, and heart tissues, in a cecal ligation and puncture (CLP)-induced polymicrobial sepsis murine model.

RESULTS

The CLP surgery induced significant changes (adj. p-value<0.05) in expression of hundreds of transcripts in the four organs tested, with the highest number exceeding 2,000 differentially expressed genes (DEGs) in all organs at 12 hours post-CLP. Over-representation analysis by functional annotations of DEGs to the Reactome database revealed the immune system, hemostasis, lipid metabolism, signal transduction, and extracellular matrix remodeling biological processes as significantly altered in at least two organs, while metabolism of proteins and RNA were revelaed as being liver tissue specific in the early phase of sepsis.

CONCLUSION

RNA sequencing across organs and time-points in the CLP murine model allowed us to study the trajectories of transcriptome changes demonstrating alterations common across multiple organs as well as biological pathways altered in an organ-specific manner. These findings could pave new directions in the research of sepsis-induced MODS and indicate new sepsis treatment strategies.

Perioperative thrombocytopenia

PURPOSE OF REVIEW

In this review, we discuss recent developments and trends in the perioperative management of thrombocytopenia.

RECENT FINDINGS

Large contemporary data base studies show that preoperative thrombocytopenia is present in about 8% of asymptomatic patients, and is associated with increased risks for bleeding and 30-day mortality. Traditionally specific threshold platelet counts were recommended for specific procedures. However, the risk of bleeding may not correlate well with platelet counts and varies with platelet function depending on the underlying etiology. Evidence to support prophylactic platelet transfusion is limited and refractoriness to platelet transfusion is common. A number of options exist to optimize platelet counts prior to procedures, which include steroids, intravenous immunoglobulin, thrombopoietin receptor agonists, and monoclonal antibodies. In addition, intraoperative alternatives and adjuncts to transfusion should be considered. It appears reasonable to use prophylactic desmopressin and antifibrinolytic agents, whereas activated recombinant factor VII could be considered in severe bleeding. Other options include enhancing thrombin generation with prothrombin complex concentrate or increasing fibrinogen levels with fibrinogen concentrate or cryoprecipitate.

SUMMARY

Given the lack of good quality evidence, much research remains to be done. However, with a multidisciplinary multimodal perioperative strategy, the risk of bleeding can be decreased effectively.

Platelet Microparticles Enriched in miR-223 Reduce ICAM-1-Dependent Vascular Inflammation in Septic Conditions

In the process of sepsis, activated platelets shed microvesicles containing microRNAs (miRNAs), which can be internalized by distinct recipient cells in circulation, consequently eliciting a potent capability to regulate their cellular functions in different diseases. In the present study, activated human platelets transferring miR-223 into endothelial cells via platelet-derived microparticles (PMPs) was investigated in vitro during septic conditions with a proposed mechanism involving in downregulation of the enhanced expression of intercellular adhesion molecule-1 (ICAM-1). The uptake of PMPs encasing miR-223 and the adhesion of peripheral blood mononuclear cells (PBMCs) on human coronary artery endothelial cells (HCAECs) were observed by immunofluorescence microscopy upon co-culture with PMPs isolated from sepsis or control plasma. The expression of miR-223-3p and its gene target ICAM1 in HCAECs were quantified by RT-qPCR and ELISA after the cells were incubated with septic or control PMPs, whose levels were induced with thrombin-receptor activating peptide (TRAP). Leukocyte-depleted platelets (LDPs) from septic patients showed a decreased miR-223 level, while septic plasma and PMPs revealed an elevated miRNA level compared to control samples. Similarly, TRAP-activated LDPs demonstrated a reduced intracellular miR-223 expression, while increased levels in the supernatant and PMP isolates were observed vs. untreated samples. Furthermore, TNF-α alone resulted in decreased miR-223 and elevated ICAM1 levels in HCAECs, while PMPs raised the miRNA level that was associated with downregulated ICAM1 expression at both mRNA and protein levels under TNF-α treatment. Importantly, miR-223 was turned out not to be newly synthesized as shown in unchanged pre-miR-223 level, and mature miR-223 expression was also elevated in the presence of PMPs in HCAECs after transfection with Dicer1 siRNA. In addition, septic PMPs containing miR-223 decreased ICAM1 with a reduction of PBMC binding to HCAECs. In conclusion, septic platelets released PMPs carrying functional miR-223 lower ICAM1 expression in endothelial cells, which may be a protective role against excessive sepsis-induced vascular inflammation.

Platelet count patterns and patient outcomes in sepsis at a tertiary care center: Beyond the APACHE score

Acute physiology and chronic health evaluation II (APACHE-II) scoring system is used to classify disease severity of patients in the intensive care unit. However, several limitations render the scoring system inadequate in identifying risk factors associated with outcomes. Little is known about the association of platelet count patterns, and the timing of platelet count and other hematologic parameters in predicting mortality in patients with sepsis.This retrospective observational study included 205 septic shock patients, with an overall mortality of 47.8%, enrolled at a tertiary care hospital in Riyadh, Kingdom of Saudi Arabia between 2018 and 2020. Bivariate and multivariate regression analyses were used to identify hematologic risk factors associated with mortality. We used the bivariate Pearson Correlation test to determine correlations between the tested variables and APACHE-II score.Two platelet count patterns emerged: patients with a decline in platelet count after admission (group A pattern, 93.7%) and those with their lowest platelet count at admission (group B pattern, 6.3%). The lowest mean platelet count was significantly lower in nonsurvivors (105.62 ± 10.67 × 103/μL) than in survivors (185.52 ± 10.81 × 103/μL), P < .001. Bivariate Pearson correlation revealed that the lowest platelet count and platelet count decline were significantly correlated with APACHE-II score (r = -0.250, P < .01), (r = 0.326, P < .001), respectively. In multiple logistic regression analysis, the independent mortality risk factors were degree of platelet count decline in group A (odds ratio, 1.028 [95% confidence interval: 1.012-1.045], P = .001) and platelet pattern in group B (odds ratio, 6.901 [95% confidence interval: 1.446-32.932], P = .015). The patterns, values, subsets, and ratios of white blood cell count were not significantly associated with mortality.Nadir platelet count and timing, and degree of platelet count decline are useful markers to predict mortality in early septic shock. Therefore, platelet count patterns might enhance the performance of severity scoring systems in the intensive care unit.

Comparison of Mean Platelet Counts in Preterm Infants with and without Retinopathy of Prematurity

Platelets are a primary source of pro- and anti-angiogenic cytokines. However, the evidence of their role in retinopathy of prematurity (ROP) is controversial. This retrospective study aimed to compare mean weekly platelet counts between infants with and without ROP over the first 6 weeks of life. A total of 93 infants matched by gestational age and birth weight were recruited (31 with ROP, 62 without ROP). Weekly mean platelet counts and other related risk factors were documented. The repeated measure analysis of variance (ANOVA) and the repeated measure analysis of covariance (ANCOVA) were used to compare mean platelet counts over time between the two groups, with and without adjusting for confounders. We found significant differences in the weekly mean platelet counts of infants with and without ROP over the first 6 weeks of life (p = 0.002). These differences disappeared after adjusting for covariates (p = 0.489). Lower mean platelet counts in ROP infants are not directly related to ROP, but rather to the presence of other risk factors for ROP, such as culture-proven sepsis, blood transfusion and bronchopulmonary dysplasia.

Lack of early platelet and leukocyte activation can indicate complications after major burn injury

BACKGROUND

Major burn injury causes massive tissue destruction consequently enhanced platelet function and leukocyte-mediated inflammatory response.

METHODS

In a prospective, observational study 23 consecutive patients with more than 20% body surface burn injury were followed for five days (T1-T5) after admission to a university intensive care (ICU). Platelet and leukocyte antisedimentation rate (PAR and LAR) was measured by one-hour gravity sedimentation. It detects the percentage of total platelet and leukocyte number crossed the half line of blood sample column, therefore, they can be regarded as cells of decreased specific gravity. We aimed to investigate the time course of PAR and LAR after burn injury, as the trend of platelet and the leukocyte activation in the early post-burn period.

RESULTS

Daily mean PAR and LAR values continuously increased in the observation period (T1 to T5). Daily mean PAR and LAR were lower in ICU non-survivors (n = 7) compared to survivors (n = 16) between T2 and T4 (p < 0.05 and p < 0.01). PAR values of septic patients (n = 10) were lower than that of non-septic ones (n = 13, p < 0.01 at T5).

CONCLUSIONS

Both PAR and LAR, as novel bedside test can predict septic complications and unfavorable outcome after major burn injury. Further studies with higher sample size are warranted.

Immune gene expression networks in sepsis: A network biology approach

To study the dysregulated host immune response to infection in sepsis, gene expression profiles from the Gene Expression Omnibus (GEO) datasets GSE54514, GSE57065, GSE64456, GSE95233, GSE66099 and GSE72829 were selected. From the Kyoto Encyclopedia of Genes and Genomes (KEGG) immune system pathways, 998 unique genes were selected, and genes were classified as follows based on gene annotation from KEGG, Gene Ontology, and Reactome: adaptive immunity, antigen presentation, cytokines and chemokines, complement, hematopoiesis, innate immunity, leukocyte migration, NK cell activity, platelet activity, and signaling. After correlation matrix formation, correlation coefficient of 0.8 was selected for network generation and network analysis. Total transcriptome was analyzed for differentially expressed genes (DEG), followed by gene set enrichment analysis. The network topological structure revealed that adaptive immunity tended to form a prominent and isolated cluster in sepsis. Common genes within the cluster from the 6 datasets included CD247, CD8A, ITK, LAT, and LCK. The clustering coefficient and modularity parameters were increased in 5/6 and 4/6 datasets in the sepsis group that seemed to be associated with functional aspect of the network. GSE95233 revealed that the nonsurvivor group showed a prominent and isolated adaptive immunity cluster, whereas the survivor group had isolated complement-coagulation and platelet-related clusters. T cell receptor signaling (TCR) pathway and antigen processing and presentation pathway were down-regulated in 5/6 and 4/6 datasets, respectively. Complement and coagulation, Fc gamma, epsilon related signaling pathways were up-regulated in 5/6 datasets. Altogether, network and gene set enrichment analysis showed that adaptive-immunity-related genes along with TCR pathway were down-regulated and isolated from immune the network that seemed to be associated with unfavorable prognosis. Prominence of platelet and complement-coagulation-related genes in the immune network was associated with survival in sepsis. Complement-coagulation pathway was up-regulated in the sepsis group that was associated with favorable prognosis. Network and gene set enrichment analysis supported elucidation of sepsis pathogenesis.

Biomarkers of Platelet Activation and Their Prognostic Value in Patients With Sepsis-Associated Disseminated Intravascular Coagulopathy

Sepsis-associated disseminated intravascular coagulation (DIC) is related to marked hemostatic changes such as transient thrombocytopenia secondary to the endogenous activation and consumption of platelets. This study measured markers of platelet function in 103 adult ICU patients with clinically established sepsis-associated DIC to determine the biomarker association with disease severity. Patients were categorized as having no DIC, nonovert DIC, or overt DIC using the International Society of Thrombosis and Hemostasis scoring system. Plasma levels of CD40L, platelet factor 4 (PF4), platelet-derived microparticles, and microparticle-associated tissue factor were quantified. Markers of platelet activation were significantly elevated in patients with DIC compared to healthy individuals. This increase was independent of platelet count. Levels of PF4 differed based on the severity of DIC and differentiated nonsurvivors and survivors. These findings suggest that the markers of platelet activation in DIC may not be regulated by the number of circulating platelets and may be independent of the factors leading to their consumption.

Fluctuation in red cell distribution width predicts disseminated intravascular coagulation morbidity and mortality in sepsis: a retrospective single-center study

BACKGROUND

Red cell distribution width (RDW) values increase in many diseases and conditions, including sepsis. However, the relationship between RDW fluctuation and prognosis in patients with sepsis or the likely morbidity associated with sepsis-induced disseminated intravascular coagulation (DIC) has not been previously investigated. This study examined the association between dynamic changes to RDW and DIC occurrence in sepsis, as well as the prognostic significance of changes to RDW during hospital stay in patients with sepsis.

METHODS

We collected baseline emergency department admissions' data. All RDW values recorded during hospitalization of patients with sepsis were combined to calculate RDW standard deviation (RDW-SD) and the increase rate of RDW; we also collected data on coagulation indicators. The endpoints were 28-day mortality and sepsis-related DIC morbidity.

RESULTS

Of 232 patients included in our analysis, 66 were diagnosed with DIC (28.4%), and 86 (37.1%) died within 28 days. The RDW-SD and the increase rate of RDW were independent risk factors for 28-day mortality and sepsis-associated DIC morbidity, respectively. The DIC occurrence and mortality rate increased continually with an increasing rate of RDW of at least 6%.

CONCLUSIONS

The RDW-SD and RDW increase rate shown in the study as the indicators of RDW fluctuation can help predict sepsis-related DIC morbidity and prognosis in patients with sepsis.

Platelet-Monocyte Aggregates: Understanding Mechanisms and Functions in Sepsis

ABSTRACT

Platelets have been shown to play an important immunomodulatory role in the pathogenesis of various diseases through their interactions with other immune and nonimmune cells. Sepsis is a major cause of death in the United States, and many of the mechanisms driving sepsis pathology are still unresolved. Monocytes have recently received increasing attention in sepsis pathogenesis, and multiple studies have associated increased levels of platelet-monocyte aggregates observed early in sepsis with clinical outcomes in sepsis patients. These findings suggest platelet-monocyte aggregates may be an important prognostic indicator. However, the mechanisms leading to platelet interaction and aggregation with monocytes, and the effects of aggregation during sepsis are still poorly defined. There are few studies that have really investigated functions of platelets and monocytes together, despite a large body of research showing separate functions of platelets and monocytes in inflammation and immune responses during sepsis. The goal of this review is to provide insights into what we do know about mechanisms and biological meanings of platelet-monocyte interactions, as well as some of the technical challenges and limitations involved in studying this important potential mechanism in sepsis pathogenesis. Improving our understanding of platelet and monocyte biology in sepsis may result in identification of novel targets that can be used to positively affect outcomes in sepsis.

Preventing the development of severe COVID-19 by modifying immunothrombosis

BACKGROUND

COVID-19-associated acute respiratory distress syndrome (ARDS) is associated with significant morbidity and high levels of mortality. This paper describes the processes involved in the pathophysiology of COVID-19 from the initial infection and subsequent destruction of type II alveolar epithelial cells by SARS-CoV-2 and culminating in the development of ARDS.

MAIN BODY

The activation of alveolar cells and alveolar macrophages leads to the release of large quantities of proinflammatory cytokines and chemokines and their translocation into the pulmonary vasculature. The presence of these inflammatory mediators in the vascular compartment leads to the activation of vascular endothelial cells platelets and neutrophils and the subsequent formation of platelet neutrophil complexes. These complexes in concert with activated endothelial cells interact to create a state of immunothrombosis. The consequence of immunothrombosis include hypercoagulation, accelerating inflammation, fibrin deposition, migration of neutrophil extracellular traps (NETs) producing neutrophils into the alveolar apace, activation of the NLRP3 inflammazome, increased alveolar macrophage destruction and massive tissue damage by pyroptosis and necroptosis Therapeutic combinations aimed at ameliorating immunothrombosis and preventing the development of severe COVID-19 are discussed in detail.