Rethinking platelet function: thrombocytopenia induced immunodeficiency in critical illness

Association between the red cell distribution width and mortality in elderly patients with non-traumatic coma: An observational cohort study

Elevated red blood cell distribution width (RDW) can be associated with disease severity. However, studies on RDW for the prognosis of elderly patients with non-traumatic coma (NTC) are lacking. This study aims to examine the relationship between RDW and outcomes in elderly patients with NTC. This observational cohort study included elderly patients (aged ≥ 65 years) with NTC between January 2022 and December 2022. We measured RDW upon patient arrival at the emergency department (ED). We conducted a multivariable analysis using logistic regression of relevant covariates to predict in-hospital mortality. Survival curves based on 30-day mortality were designed using the Kaplan-Meier method. The primary outcome was in-hospital mortality, and the secondary outcome was 30-day mortality. A total of 689 patients were included in the study, and in-hospital mortality was 29.6% (n = 204). Our results found that the RDWs of non-survivors were significantly greater than those of survivors (14.6% vs 13.6%). Multivariable analysis showed that RDWs at ED arrival were independently associated with in-hospital mortality (odds ratio, 1.126; 95% confidence interval, 1.047-1.212; P < .001). The Kaplan-Meier curve indicated that the survival probability of patients with a low RDW was greater than those with a high RDW. Having a high RDW at ED arrival was associated with in-hospital mortality in elderly patients with NTC.

Association Between Platelet Levels and 28-Day Mortality in Patients With Sepsis: A Retrospective Analysis of a Large Clinical Database MIMIC-IV

BACKGROUND

This research focused on evaluating the correlation between platelet count and sepsis prognosis, and even the dose-response relationship, in a cohort of American adults.

METHOD

Platelet counts were recorded retrospectively after hospitalization for patients admitted to Beth Israel Deaconess Medical Center's intensive care unit between 2008 and 2019. On admission to the intensive care unit, sepsis patients were divided into four categories based on platelet counts (very low < 50 × 10⁹/L, intermediate-low 50 × 10⁹-100 × 10⁹/L, low 100 × 10⁹-150 × 10⁹/L, and normal ≥ 150 × 10⁹/L). A multivariate Cox proportional risk model was used to calculate the 28-day risk of mortality in sepsis based on baseline platelet counts, and a two-piece linear regression model was used to calculate the threshold effect.

RESULTS

The risk of 28-day septic mortality was nearly 2-fold higher in the platelet very low group when compared to the low group (hazard ratios [HRs], 2.24; 95% confidence interval [CI], 1.92-2.6). Further analysis revealed a curvilinear association between platelets and the sepsis risk of death, with a saturation effect predicted at 100 × 10⁹/L. When platelet counts were below 100 × 10⁹/L, the risk of sepsis 28-day death decreased significantly with increasing platelet count levels (HR, 0.875; 95% CI, 0.84-0.90).

CONCLUSION

When platelet count was less than 100 × 10⁹/L, it was a strong predictor of the potential risk of sepsis death, which is declined by 13% for every 10 × 10⁹/L growth in platelets. When platelet counts reach up to 100 × 10⁹/L, the probability of dying to sepsis within 28 days climbs by 1% for every 10 × 10⁹/L increase in platelet count.

Blood transfusion in major emergency abdominal surgery

BACKGROUND

Major emergency abdominal surgery is associated with excess mortality. Transfusion is known to be associated with increased morbidity and emergency surgery is an independent risk factor for perioperative transfusion. The primary objectives of this study were to identify risk factors for transfusion, and secondarily to investigate the influence of transfusion on clinical outcomes after major emergency abdominal surgery.

STUDY DESIGN AND METHODS

This study combined retrospective observational data including intraoperative, postoperative, and transfusion data in patients undergoing major emergency abdominal surgery from January 2010 to October 2016 at a Danish university hospital. The primary outcome was a transfusion of any kind from initiation of surgery to postoperative day 7. Secondary outcomes included 7-, 30-, 90-day and long-term mortality (median follow-up = 34.6 months, IQR = 13.0-58.3), lengths of stay, and surgical complication rate (Clavien-Dindo score ≥ 3a).

RESULTS

A total of 1288 patients were included and 391 (30%) received a transfusion of any kind. Multivariate logistic regression identified age, hepatic comorbidity, cardiac comorbidity, post-surgical anemia, ADP-receptor inhibitors, acetylsalicylic acid, anticoagulants, and operation type as risk factors for postoperative transfusion. 60.1% of the transfused patients experienced a serious surgical complication within 30 days of surgery compared with 28.1% of the non-transfused patients (p < 0.001). Among patients receiving a postoperative transfusion, unadjusted long-term mortality was increased with a hazard ratio of 3.8 (95% CI 2.9-5.0), p < 0.01. Transfused patients had significantly higher mortality at 7-, 30-, 90- and long-term, as well as a longer hospital stay but in the multivariate analyses, transfusion was not associated with mortality.

CONCLUSION

Peri- and postoperative transfusion in relation to major emergency abdominal surgery was associated with an increased risk of postoperative complications. The potential benefits and harms of blood transfusion and clinical significance of pre- and postoperative anemia after major emergency abdominal surgery should be further studied in clinical prospective studies.

Mean platelet volume/platelet count ratio predicts long-term mortality in patients with infective endocarditis

Aim: We aimed to examine the association between baseline mean platelet volume/platelet count ratio (MPR) and all-cause mortality in patients with infective endocarditis (IE). Patients & methods: This study analyzed 218 consecutive patients with IE and divided them into four groups based on MPR quartiles. We used Kaplan-Meier survival curves to determine the cumulative survival and Cox proportional hazards models to investigate the association between MPR and all-cause mortality after hospital discharge. Results: Kaplan-Meier curves showed a gradual increase in mortality risk from the lowest MPR quartile to the highest quartile. Multivariate analysis revealed that MPR was an independent predictor of increased risk for all-cause death. Conclusion: Elevated MPR was independently associated with long-term all-cause mortality in patients with IE.

Relation between dynamic changes of platelet counts and 30-day mortality in severely burned patients

Thrombocytopenia is a common event in severely burned patients and associated with adverse outcome. The underlying relationship between the dynamic changes of platelet counts and mortality has not been well defined. We performed a 6-year retrospective chart of adult patients with a burn index of 50 or greater admitted to two burn centers and collected data on patient demographics, laboratory results, and patient outcomes. The mean daily increase in the platelet count (∆PC/∆t) from day 3 to day 10 was calculated, and 30-day mortality was determined. For the study, 141 survivors and 65 nonsurvivors were enrolled. The sequential changes in PCs presented a biphasic pattern after admission, with a slump to the nadir during the first 3 days and a subsequent recovery. With respect to 30-day mortality, compared with the AUC of APACHE-Ⅱ score (0.841), no significant difference was noted between ΔPC/ΔT and APACHE-Ⅱ score (p = 0.0648). The ΔPC/ΔT associated with the best discrimination between survivors and nonsurvivors was 20.57 × 10⁹/L due to the cutoff with optimal Youden index (0.453). By multiple logistic regression, ΔPC/ΔT ＜ 20.57 × 10⁹/L was one of the prognostic predictors of 30-day mortality. Furthermore, Kaplan-Meier estimates of hospital survival according to the size of ΔPC/ΔT revealed that a blunted increase with ΔPC/ΔT ＜ 20.57 × 10⁹/L was associated with increased 30-day mortality. A blunted daily increase in PCs, especially ΔPC/ΔT < 20.57 × 10⁹/L, is associated with increased 30-day mortality, which provides prognostic information for mortality risk assessment in severely burned patients.

Platelets Modulate Innate Immune Response Against Human Respiratory Syncytial Virus In Vitro

Detection of respiratory syncytial virus (RSV) in blood, including mononuclear leukocytes and organs other than the lung, suggests that RSV disseminates outside the respiratory tract. In this study, the role of platelets in host defense against RSV was explored using an in vitro model. Platelets, also produced in the lungs, are increasingly recognized as an important part of host immune responses and may therefore play a role in modulating lung infections and clearing RSV viremia. In human peripheral blood mononuclear cells (PBMCs), platelets significantly reduced RSV infection of monocytes, monocyte activation, and interferon (IFN)α/γ production. Direct contact of platelets with PBMCs modulated the immune response when stimulated with Poly I:C (TLR3) and R848 (TLR7/8), Toll-like receptors (TLRs) involved in the recognition of RSV, and led to an enhanced IFNα/γ production. This suggested that reduction in RSV infection of monocytes in the presence of platelets could be IFN dependent; blocking IFNα receptor 2 (IFNAR2) on PBMCs indeed increased RSV infection. In addition, IFNs were not detected when PBMCs were stimulated with inactivated RSV, indicating that infection of monocytes was important for the induction of IFN responses and that the platelet-mediated reduced RSV infection was responsible for the decreased IFN levels. Furthermore, platelets could internalize RSV reducing the amount of viral particles that could infect monocytes. Our findings suggest that platelets may play a role in the clearance of RSV viremia by internalizing viral particles and by enhancing type I IFN production from PBMCs, which subsequently exert antiviral effect on host cells.

Effect of Transfusion Strategy in Acute Non-variceal Upper Gastrointestinal Bleeding: A Nationwide Study of 5861 Hospital Admissions in Denmark

BACKGROUND

Acute non-variceal upper gastrointestinal bleeding (NVUGIB) is a common cause of admissions as well as aggressive transfusion of blood products. Whether the transfusion strategy in NVUGIB impacts on hemostasis is unknown and constitutes the focus of this study.

METHOD

Retrospective analysis of all hospital admissions in Denmark between 2011 and 2013 where hemostatic endoscopic interventions in either the stomach or duodenum had been employed. Regression modeling was used to predict the effect of units transfused of packed red blood cells (PRBC), fresh frozen plasma (FFP), and platelets (PLT) on primary outcome 30-day mortality as well as secondary hemostasis-related outcomes and need for re-endoscopy and conversion to surgery. The model was corrected for confounders, including transfusion of other blood products (PRBC, FFP, and PLT, respectively), patient age as well as pre-existing medical conditions.

RESULTS

5107 patients received 10783 therapeutic endoscopic interventions. Units of PRBC transfused were identified as a predictor of re-endoscopy, surgery, and 30-day mortality with odds ratio (OR) 1.08 (1.06-1.09, p < 0.01), 1.05 (1.03-1.07, p < 0.01), and 1.04 (1.01-1.06, p < 0.01), respectively. Units of FFP transfused were associated with a higher risk of surgery and 30-day mortality with OR 1.05 (1.02-1.08, p < 0.01) and 1.04 (1.02-1.07, p < 0.01), respectively. Units of PLTs transfused were independently associated with a reduction in risk of re-endoscopy 0.93 (0.87-0.98, p = 0.02). A high ratio of PRBC:FFP:PLT (1:1:1) was associated with reduced need for re-endoscopy OR 0.23 (0.06-0.67, p = 0.01) but increased mortality with OR 3.60 (1.34-11.38, p = 0.02).

CONCLUSION

PRBC transfusion was associated with adverse events, including 30-day mortality and failure of hemostasis. In contrast, transfusion of PLT was associated with a reduction in need for re-endoscopy.

Fresh Frozen Plasma Modulates Brain Gene Expression in a Swine Model of Traumatic Brain Injury and Shock: A Network Analysis

BACKGROUND

Resuscitation with fresh frozen plasma (FFP) decreases brain lesion size and swelling in a swine model of traumatic brain injury and hemorrhagic shock. We hypothesized that brain gene expression profiles after traumatic brain injury and hemorrhagic shock would be modulated by FFP resuscitation.

STUDY DESIGN

Fifteen swine underwent a protocol of traumatic brain injury and hemorrhagic shock and 2 hours of shock followed by resuscitation with FFP, normal saline, or hetastarch (5/group). After 6 hours, brain RNA was isolated and hybridized onto a porcine gene ST 1.1 microarray. Weighted gene correlation network analysis was used to identify clusters of highly coexpressed genes. Principal component analysis identified cluster eigenvectors, indicating overall direction and magnitude of cluster gene expression. Using linear regression, cluster eigenvectors were associated with treatment as well as brain lesion size and swelling. Results were post-hoc corrected using false discovery rate. Relevant gene clusters were subjected to pathway analysis using the Reactome tool.

RESULTS

Network analysis identified 322 gene expression clusters (total of 12,462 coexpressed genes). Fresh frozen plasma resuscitation (but not normal saline or hetastarch) was positively associated with 2 distinct gene clusters (termed A and B) comprising 493 genes. Gene expression in both clusters was negatively associated with brain swelling, and cluster B was also negatively associated with lesion size. Pathway analysis revealed an upregulation of genes involved in metabolic and platelet signaling, as well as collagen formation and downregulation of inflammation.

CONCLUSIONS

Fresh frozen plasma resuscitation in this model was associated with downregulation of inflammatory pathway genes and expression of gene clusters mapping to increased metabolic and platelet signaling, which, in turn, was reversely associated with brain swelling.

Haemostatic function and biomarkers of endothelial damage before and after platelet transfusion in patients with acute myeloid leukaemia

OBJECTIVES

The beneficial effect of platelet transfusion on haemostasis is well established, but there is emerging evidence that platelet transfusion induces an inflammatory response in vascular endothelial cells.

BACKGROUND

We investigated haemostatic function and endothelial biomarkers before and after platelet transfusion in patients with acute myeloid leukaemia.

MATERIALS AND METHODS

Blood was sampled before, 1 and 24 h after platelet transfusion. Primary and secondary haemostasis was evaluated by whole blood aggregometry (Multiplate) and thromboelastography (TEG). Endothelial biomarkers (sICAM-1, syndecan-1, sThrombomodulin, sVE-Cadherin) and platelet activation biomarkers (sCD40L, TGF-beta) were investigated along with haematology/biochemistry analyses.

RESULTS

Twenty-two patients were included. Despite continued low platelet counts, platelet transfusion normalised the median values of most TEG parameters and slightly increased platelet aggregation (all P < 0·05). Endothelial biomarkers were not significantly affected by transfusion. The 1 h sCD40L level correlated positively with Syndecan-1 and soluble thrombomodulin delta values, biomarkers of endothelial damage (both P = 0·005).

CONCLUSION

Platelet transfusion improved haemostasis, whereas post-transfusion increases in sCD40L were associated with endothelial damage, indicating that transfused platelets and platelet-derived pro-inflammatory mediators may have opposite effects on the endothelium.

Circulating levels of platelet α-granule cytokines in trauma patients

OBJECTIVE AND DESIGN

To elucidate whether platelets differentiate cytokine release following trauma, we prospectively measured three major platelet-derived cytokines in 213 trauma patients on hospital arrival.

METHODS

We measured plasma levels of the anti-inflammatory β-thromboglobulins (βTGs), transforming growth factor-β1 (TGFβ1) and the pro-inflammatory platelet factor 4 (PF4) cytokines. We also measured soluble glycoprotein VI (sGPVI), procoagulant platelet microparticles (PMPs) and white blood cell (WBC) counts, and evaluated in vitro platelet function in primary and secondary haemostasis by aggregometry and thromboelastometry, respectively. We evaluated associations of each cytokine by multivariate regression including injury severity score (ISS), WBC counts, sGPVI and platelet counts as explanatory variables.

RESULTS

Severely injured patients (ISS > 15) had higher levels of βTGs and TGFβ1 (both p < 0.01) but lower levels of PF4 (p = 0.02). GPVI and PMPs levels correlated with TGFβ1 and PF4 whereas we found no significant association between cytokine levels and measures of haemostasis. By multivariate regression, a high WBC count was associated with high levels of TGFβ1 (p = 0.01) and βTGs (p < 0.01) but with low levels of PF4 (p = 0.03).

CONCLUSION

Severely injured patients had higher levels of βTGs and TGFβ1 but lower levels of the PF4; a high WBC count predicted this anti-inflammatory profile of platelet cytokines.

Fresh frozen plasma resuscitation attenuates platelet dysfunction compared with normal saline in a large animal model of multisystem trauma

BACKGROUND

Platelet dysfunction following trauma has been identified as an independent predictor of mortality. We hypothesized that fresh frozen plasma (FFP) resuscitation would attenuate platelet dysfunction compared with 0.9% normal saline (NS).

METHODS

Twelve swine were subjected to multisystem trauma (traumatic brain injury, liver injury, rib fracture, and soft tissue injury) with hemorrhagic shock (40% of estimated blood volume). Animals were left in shock (mean arterial pressure, 30-35 mm Hg) for 2 hours followed by resuscitation with three times shed volume NS (n = 6) or one times volume FFP (n = 6) and monitored for 6 hours. Platelet function was assessed by adenosine diphosphate (ADP)-induced platelet aggregation at baseline, after 2 hours of shock following resuscitation, and 6 hours after resuscitation. Fibrinogen levels and markers of platelet activation (transforming growth factor β [TGF-β], sP-Selectin, and CD40L) as well as endothelial injury (intercellular adhesion molecule 1 [ICAM-1], vascular cell adhesion molecule 1 [VCAM-1]) were also assayed. Thromboelastography was used to measure clotting activity.

RESULTS

ADP-induced platelet aggregation was significantly higher in the FFP group (46.3 U vs. 25.5 U, p < 0.01) following resuscitation. This was associated with higher fibrinogen levels (202 mg/dL vs. 80 mg/dL, p < 0.01) but lower endothelial activation (VCAM-1, 1.25 ng/mL vs. 3.87 ng/mL, p = 0.05). Other markers did not differ.After 6 hours of observation, ADP-induced platelet aggregation remained higher in the FFP group (53.8 U vs. 37.0 U, p = 0.03) as was fibrinogen levels (229 mg/dL vs. 153 mg/dL, p < 0.01). Endothelial activation was lower (ICAM-1, 21.0 ng/mL vs. 24.4 ng/mL, p = 0.05), whereas TGF-β levels were higher (2,138 pg/mL vs. 1,802 pg/mL, p = 0.03) in the FFP group. Other markers did not differ. Thromboelastography revealed increased clot strength in the FFP group at both postresuscitation time points.

CONCLUSION

Resuscitation with FFP resulted in an immediate and sustained improvement in platelet function and clot strength compared with high-volume NS resuscitation. This was associated with an increase in fibrinogen levels and an attenuation of endothelial activation.

Active exercise in critically ill adults affected by thrombocytopaenia

Introduction

Thrombocytopaenia (TCP), or low platelet count, is a haematological disorder that commonly occurs in critically ill patients and is defined as a platelet count below 100 000/μL. Patients are at higher risk of muscular atrophy and other complications after prolonged bed rest. This literature review aims to clarify the appropriateness of active exercise in critically ill adult patients with TCP.

Methods

A review of the literature was conducted using the following key words that are PubMed medical subheading (MeSH) terms: ‘critical illness’, ‘exercise therapy’, ‘manual therapy’, ‘physical therapy’, ‘physiotherapy’, ‘postoperative care’, ‘rehabilitation’, ‘thrombocytopenia’, and ‘thrombopenia’. The search was limited by publication date (2000 to 2013) and language (English only) in three main databases: PubMed, SCOPUS, and CINAHL.

Results

The key word searches found a total of 78 citations. Of these, only those meeting the inclusion criteria were selected after reading the title and abstract. Two studies were included after reading the full-texts. Exercise is used to treat muscular atrophy in critically ill adult patients, and rehabilitation plays an important role in the care pathway. Results of our analysis do not support evidence for or against exercise in critically ill adult patients with TCP; therefore, health professionals must pay close attention to the presence of signs of bleeding in these patients when proposing exercise.

Discussion

Surprisingly, no study was found that directly covered this issue. Aggressive exercise may not be appropriate in patients with very low platelet counts. On the other hand, critically ill patients are at high risk of muscular atrophy due to the forced bed rest, especially after complex surgery or in prolonged hospitalisation. Physiotherapists and those providing care must share their observations with the rest of the multidisciplinary team before treatment starts.

Conclusions

Active exercise in critically ill adult patients with severe TCP must be personalised and platelet count carefully monitored before proposing physical activity. Physical recovery can be challenging in critically ill adult patients, and it can be limited by severe TCP, mostly when bleeding is present.

Discrepant fibrinolytic response in plasma and whole blood during experimental endotoxemia in healthy volunteers

Background

Sepsis induces early activation of coagulation and fibrinolysis followed by late fibrinolytic shutdown and progressive endothelial damage. The aim of the present study was to investigate and compare the functional hemostatic response in whole blood and plasma during experimental human endotoxemia by the platelet function analyzer, Multiplate and by standard and modified thrombelastography (TEG).

Methods

Prospective physiologic study of nine healthy male volunteers undergoing endotoxemia by means of a 4-hour infusion of E. coli lipopolysaccharide (LPS, 0.5 ng/kg/hour), with blood sampled at baseline and at 4 h and 6 h. Physiological and standard biochemical data and coagulation tests, TEG (whole blood: TEG, heparinase-TEG, Functional Fibrinogen; plasma: TEG±tissue-type plasminogen activator (tPA)) and Multiplate (TRAPtest, ADPtest, ASPItest, COLtest) were recorded. Mixed models with Tukey post hoc tests and correlations were applied.

Results

Endotoxemia induced acute SIRS with increased HR, temperature, WBC, CRP and procalcitonin and decreased blood pressure. It also induced a hemostatic response with platelet consumption and reduced APTT while INR increased (all p<0.05). Platelet aggregation decreased (all tests, p<0.05), whereas TEG whole blood clot firmness increased (G, p = 0.05). Furthermore, during endotoxemia (4 h), whole blood fibrinolysis increased (clot lysis time (CLT), p<0.001) and Functional Fibrinogen clot strength decreased (p = 0.049). After endotoxemia (6 h), whole blood fibrinolysis was reduced (CLT, p<0.05). In contrast to findings in whole blood, the plasma fibrin clot became progressively more resistant towards tPA-induced fibrinolysis at both 4 h and 6 h (p<0.001).

Conclusions

Endotoxemia induced a hemostatic response with reduced primary but enhanced secondary hemostasis, enhanced early fibrinolysis and fibrinogen consumption followed by downregulation of fibrinolysis, with a discrepant fibrinolytic response in plasma and whole blood. The finding that blood cells are critically involved in the vasculo-fibrinolytic response to acute inflammation is important given that disturbances in the vascular system contribute significantly to morbidity and mortality in critically ill patients.

Consecutive thrombelastography clot strength profiles in patients with severe sepsis and their association with 28-day mortality: a prospective study

PURPOSE

The aim of this study was to assess associations between consecutive thrombelastography (TEG) profiles and standard coagulation tests and disease severity and mortality in patients with severe sepsis.

MATERIALS AND METHODS

This was a prospective observational study of adults with severe sepsis admitted to the intensive care unit (ICU). Clinical scores/variables, infection, TEG, biochemistry, therapy, and overall mortality were recorded.

RESULTS

Fifty patients (60% men, median age 62 years, 28-day mortality 24%) were included. At admission, 22%, 48%, and 30% had a hypocoagulable, normocoagulable, and hypercoagulable TEG clot strength (maximum amplitude [MA]), respectively. Hypocoagulable patients had higher Sequential Organ Failure Assessment and disseminated intravascular coagulation scores compared with hypercoagulable patients and higher 28-day mortality compared with normocoagulable patients (all P < .05). Most patients (73%-91%) displayed a TEG MA comparable with the admission profile during the initial 4 ICU days or until death/discharge. Patients progressing to hypocoagulable MA had a high early mortality (80%) and hypocoagulable MA independently predicted 28-day mortality (adjusted odds ratio, 4.29 [95% confidence interval, 1.35-13.65], P = .014). In hypocoagulable and hypercoagulable patients, only fibrinogen (P = .041 and P < .001, respectively) contributed independently to clot strength, whereas both platelets (P < .001) and fibrinogen (P < .001) contributed independently to clot strength in normocoagulable patients.

CONCLUSIONS

The ICU admission TEG MA remained constant for several days in patients with severe sepsis and hypocoagulable MA independently predicted 28-day mortality.

High sCD40L levels early after trauma are associated with enhanced shock, sympathoadrenal activation, tissue and endothelial damage, coagulopathy and mortality

BACKGROUND

Severe injury activates the sympathoadrenal, hemostatic and inflammatory systems, but a maladapted response may contribute to a poor outcome. Soluble CD40L is a platelet-derived mediator that links inflammation, hemostasis and vascular dysfunction.

OBJECTIVES

To investigate the association between the sCD40L level and tissue injury, shock, coagulopathy and mortality in trauma patients.

METHODS

A prospective, observational study of 80 trauma patients admitted to a Level I Trauma Center. Data on demography, biochemistry, Injury Severity Score (ISS) and 30-day mortality were recorded and admission plasma/serum analyzed for sCD40L and biomarkers reflecting sympathoadrenal activation (adrenaline, noradrenaline), tissue/endothelial cell/glycocalyx damage (histone-complexed DNA fragments [hcDNA], Annexin V, thrombomodulin and syndecan-1), coagulation activation/inhibition (PF1.2, TAT-complex, antithrombin, protein C, activated protein C, sEPCR, TFPI, von Willebrand factor [VWF], fibrinogen and factor [F] XIII), fibrinolysis (D-dimer, tissue plasminogen activator [tPA] and plasminogen activator inhibitor-1 [PAI-1]) and inflammation (interleukin-6 [IL-6] and sC5b-9). We compared patients stratified by median sCD40L level and investigated predictive values of sCD40L for mortality.

RESULTS

High circulating sCD40L was associated with enhanced tissue and endothelial damage (ISS, hcDNA, Annexin V, syndecan-1 and sTM), shock (pH, standard base excess), sympathoadrenal activation (adrenaline) and coagulopathy evidenced by reduced thrombin generation (PF1.2), hyperfibrinolysis (D-dimer), increased activated partial thromboplastin time (APTT) and inflammation (IL-6) (all P < 0.05). A higher ISS (P = 0.017), adrenaline (P = 0.049) and platelet count (P = 0.012) and lower pH (P =0.002) were associated with higher sCD40L by multivariate linear regression analysis. High circulating sCD40L (odds ratio [OR] 1.84 [95% CI 1.05-3.23], P = 0.034), high age (P = 0.002) and low Glasgow Coma Score (GCS) pre-hospital (P = 0.002) were independent predictors of increased mortality.

CONCLUSIONS

High early sCD40L levels in trauma patients reflect tissue injury, shock, coagulopathy and sympathoadrenal activation and predict mortality. As sCD40L has pro-inflammatory activity and activates the endothelium, sCD40L may be involved in trauma-induced endothelial damage and coagulopathy.