Thrombocytopenia in the sepsis syndrome: role of hemophagocytosis and macrophage colony-stimulating factor

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.

Value of hemophagocytosis in the diagnosis of hemophagocytic lymphohistiocytosis in critically ill patients

BACKGROUND

Ferritin is an established biomarker in the diagnosis of secondary hemophagocytic lymphohistiocytosis (HLH), which is diagnosed by the HLH-2004 criteria. Among these criteria, detection of hemophagocytosis through invasive procedures may delay early life saving treatment. Our aim was to investigate the value of hemophagocytosis in diagnosing HLH in critically ill patients.

METHODS

In this secondary analysis of a retrospective observational study, we included all patients aged ≥18 years and admitted to any adult ICU at Charité-Universitätsmedizin Berlin between January 2006 and August 2018, who had hyperferritinemia (≥500 μg/L) and underwent bone marrow biopsy during their ICU course.

RESULTS

Two hundred fifty-two patients were included, of whom 31 (12.3%) showed hemophagocytosis. In multivariable logistic regression analysis, maximum ferritin was independently associated with hemophagocytosis. By removing hemophagocytosis from HLH-2004 criteria and HScore, prediction accuracy for HLH diagnosis was only marginally decreased compared to the original scores.

CONCLUSIONS

Our results strengthen the diagnostic value of ferritin and underline the importance of considering HLH diagnosis in patients with high ferritin but only four fulfilled HLH-2004 criteria, when hemophagocytosis was not assessed or not detectable. Proof of hemophagocytosis is not required for a reliable HLH diagnosis.

Thrombocytopenia in Klebsiella pneumoniae liver abscess: a retrospective study on its correlation with disease severity and potential causes

Objective

Thrombocytopenia is commonly associated with infectious diseases and serves as an indicator of disease severity. However, reports on its manifestation in conjunction with Klebsiella pneumoniae liver abscess (KPLA) are scarce. The present study sought to elucidate the correlation between thrombocytopenia and KPLA severity and delve into the etiological factors contributing to the incidence of thrombocytopenia.

Materials and methods

A retrospective analysis of the clinical data from patients with KPLA admitted between June 2012 and June 2023 was performed. Baseline characteristics, biochemical assessments, therapeutic interventions, complications, and clinical outcomes were compared between patients with and without thrombocytopenia. To investigate the potential etiologies underlying thrombocytopenia, the association between platelet count reduction and thrombophlebitis was examined, with a particular focus on platelet consumption. Furthermore, bone marrow aspiration results were evaluated to assess platelet production anomalies.

Results

A total of 361 KPLA patients were included in the study, among whom 60 (17%) had concurrent thrombocytopenia. Those in the thrombocytopenia group exhibited significantly higher rates of thrombophlebitis (p = 0.042), extrahepatic metastatic infection (p = 0.01), septic shock (p = 0.024), admissions to the intensive care unit (p = 0.002), and in-hospital mortality (p = 0.045). Multivariate analysis revealed that thrombocytopenia (odds ratio, 2.125; 95% confidence interval, 1.114-4.056; p = 0.022) was independently associated with thrombophlebitis. Among the thrombocytopenic patients, eight underwent bone marrow aspiration, and six (75%) had impaired medullar platelet production. After treatment, 88.6% of thrombocytopenic patients (n = 47) demonstrated recovery in their platelet counts with a median recovery time of five days (interquartile range, 3-6 days).

Conclusions

Thrombocytopenia in patients with KPLA is indicative of increased disease severity. The underlying etiologies for thrombocytopenia may include impaired platelet production within the bone marrow and augmented peripheral platelet consumption as evidenced by the presence of thrombophlebitis.

Platelet Count During Course of Cardiogenic Shock

The study investigates the prognostic value of the platelet count in patients with cardiogenic shock (CS). Limited data regarding the prognostic value of platelets in patients suffering from CS is available. Consecutive patients with CS from 2019 to 2021 were included at one institution. Firstly, the prognostic value of the baseline platelet count was tested for 30-day all-cause mortality. Thereafter, the prognostic impact of platelet decline during course of intensive care unit (ICU) hospitalization was assessed. A total of 249 CS patients were included with a median platelet count of 224 × 10 6 /ml. No association of the baseline platelet count with the risk of 30-day all-cause mortality was found (log-rank p = 0.563; hazard ratio [HR] = 0.879; 95% confidence interval [CI] 0.557-1.387; p = 0.579). In contrast, a decrease of platelet count by ≥ 25% from day 1 to day 3 was associated with an increased risk of 30-day all-cause mortality (55% vs. 39%; log-rank p = 0.045; HR = 1.585; 95% CI 0.996-2.521; p = 0.052), which was still evident after multivariable adjustment (HR = 1.951; 95% CI 1.116-3.412; p = 0.019). Platelet decrease during the course of ICU hospitalization but not the baseline platelet count was associated with an increased risk of 30-day all-cause mortality in CS patients.

Diagnostic and prognostic role of platelets in patients with sepsis and septic shock

Studies investigating the prognostic role of platelets commonly include critically ill patients, whereas data regarding the prognostic impact of platelet count in patients admitted with sepsis and septic shock is limited. Therefore, the study investigates the prognostic role of platelet count in patients with sepsis and septic shock. Consecutive patients with sepsis and septic shock from 2019 to 2021 were included monocentrically. Blood samples were retrieved from the day of disease onset (day 1), days 2, 3, 5, 7 and 10. Firstly, the diagnostic value of platelet count was tested for septic shock compared to sepsis. Secondly, the prognostic value of platelet count was tested for 30-day all-cause mortality. Statistical analyses included univariable t-test, Spearman's correlation, C-statistics, Kaplan-Meier analyses, as well as multivariable mixed analysis of variance (ANOVA), Cox proportional regression analyses and propensity score matching. A total of 358 patients with sepsis and septic shock were included with a median platelet count of 176 × 10⁶/ml. The presence of thrombocytopenia (i.e. <150 × 10⁶/ml) was associated with increased risk of 30-day mortality (HR = 1.409; 95% CI 1.057-1.878; p = .019), which was still demonstrated after propensity score matching. During the course of sepsis, a nadir was observed on sepsis day 5 with a decrease in the mean platelet count by 21.5%. Especially serum lactate, mean arterial pressure and the presence of malignancies were found to predict platelet decline during the course of sepsis/septic shock. The presence of platelet decline >25% was associated with an increased risk of 30-day all-cause mortality (HR = 1.484; 95% CI 1.045-2.109; p = .028). Following platelet decline, recovery was observed from day 5 to day 10 (mean increase 7.5%). However, platelet recovery was not found to be associated with 30-day all-cause mortality (HR = 1.072; 95% CI 0.567-2.026; p = .832). In conclusion, both thrombocytopenia and platelet decline during the course of sepsis were associated with an increased risk of 30-day all-mortality in patients admitted with sepsis or septic shock.

Current knowledge of thrombocytopenia in sepsis and COVID-19

Thrombocytopenia, characterized by a decrease in platelet count, is commonly observed in sepsis and COVID-19. In sepsis, thrombocytopenia can result from various mechanisms, including impaired platelet production in the bone marrow, accelerated platelet destruction due to increased inflammation, sequestration of platelets in the spleen, immune-mediated platelet destruction, or dysregulated host responses. Similarly, thrombocytopenia has been reported in COVID-19 patients, but the immune-related mechanisms underlying this association remain unclear. Notably, interventions targeting thrombocytopenia have shown potential for improving outcomes in both sepsis and COVID-19 patients. Understanding these mechanisms is crucial for developing effective treatments.

Heparin, Heparan Sulphate and Sepsis: Potential New Options for Treatment

Sepsis is a life-threatening hyperreaction to infection in which excessive inflammatory and immune responses cause damage to host tissues and organs. The glycosaminoglycan heparan sulphate (HS) is a major component of the cell surface glycocalyx. Cell surface HS modulates several of the mechanisms involved in sepsis such as pathogen interactions with the host cell and neutrophil recruitment and is a target for the pro-inflammatory enzyme heparanase. Heparin, a close structural relative of HS, is used in medicine as a powerful anticoagulant and antithrombotic. Many studies have shown that heparin can influence the course of sepsis-related processes as a result of its structural similarity to HS, including its strong negative charge. The anticoagulant activity of heparin, however, limits its potential in treatment of inflammatory conditions by introducing the risk of bleeding and other adverse side-effects. As the anticoagulant potency of heparin is largely determined by a single well-defined structural feature, it has been possible to develop heparin derivatives and mimetic compounds with reduced anticoagulant activity. Such heparin mimetics may have potential for use as therapeutic agents in the context of sepsis.

Random Skin Biopsy Is a Useful Procedure in the Evaluation of Hemophagocytic Lymphohistiocytosis: A Case Report and Review of Literature

ABSTRACT

Hemophagocytic lymphohistiocytosis (HLH) is a rare, life-threatening syndrome, characterized by aberrant activation of T lymphocytes and macrophages leading to hypercytokinemia. HLH can be familial or a result of various secondary etiologies. We present a case of a 46-year-old woman with a past medical history of multiple sclerosis on rituximab who presented as a transfer from an outside hospital with numerous clinical abnormalities including recurrent episodes of fever of unknown origin for 3 weeks, persistent leukocytosis, hypertriglyceridemia, and steatohepatitis. Given the uncertain nature of her illness, she underwent a random skin biopsy from the abdominal region to exclude hematolymphoid malignancy. Histopathology revealed a brisk histiocytic rich dermal infiltrate accompanied by perivascular lymphocytic infiltrate. The histiocytes were enlarged and positive for muraminadase and CD68 stains exhibiting hemophagocytosis focally. As per the HLH-2004 protocol, our patient met the diagnostic criteria of HLH. Concurrent bone marrow biopsy revealed similar rare hemophagocytosis. Cytogenetics and molecular studies were negative, supporting secondary HLH.

Renal involvement as a unique manifestation of hemophagocytic syndrome

Renal-limited hemophagocytic syndrome (HPS) is a rare clinical setting characterized by abnormal activation of the immune system. Fever associated with pancytopenia, hepatosplenomegaly with liver dysfunction, and hypofibrinogenemia are usually observed in HPS. From a histological level, the presence of non-malignant macrophages infiltrating bone marrow and organs represents the hallmark of this condition. Non-malignant macrophages are associated with phagocytizing activities involving other blood cells. While primary HPS is usually associated with inherited dysregulation of the immune system, secondary HPS usually occurs in the context of infection or is linked to a neoplastic process. Clinical presentation varies and can potentially lead to life-threatening settings. While renal involvement has frequently been reported, however, detailed descriptions of the kidney manifestations of HPS are lacking. More critically, the diagnosis of HPS is rarely supported by renal biopsy specimens. We report four rare cases of biopsy-proven renal-limited HPS in patients presenting with acute kidney injury (AKI). The available evidence on this topic is critically discussed in light of the possible emergence of an autonomous entity characterized by an isolated kidney involvement.

An Evidence-Based Guideline Improves Outcomes for Patients With Hemophagocytic Lymphohistiocytosis and Macrophage Activation Syndrome

OBJECTIVE

To compare clinical outcomes in children with hemophagocytic lymphohistiocytosis (HLH) and macrophage activation syndrome (MAS) who were managed before and after implementation of an evidence-based guideline (EBG).

METHODS

A management algorithm for MAS-HLH was developed at our institution based on literature review, expert opinion, and consensus building across multiple pediatric subspecialties. An electronic medical record search retrospectively identified hospitalized patients with MAS-HLH in the pre-EBG (October 15, 2015, to December 4, 2017) and post-EBG (January 1, 2018, to January 21, 2020) time periods. Predetermined outcome metrics were evaluated in the 2 cohorts.

RESULTS

After the EBG launch, 57 children were identified by house staff as potential patients with MAS-HLH, and rheumatology was consulted for management. Ultimately, 17 patients were diagnosed with MAS-HLH by the treating team. Of these, 59% met HLH 2004 criteria, and 94% met 2016 classification criteria for MAS complicating systemic juvenile idiopathic arthritis. There was a statistically significant reduction in mortality from 50% before implementation of the EBG to 6% in the post-EBG cohort (P = 0.02). There was a significant improvement in time to 50% reduction in C-reactive protein level in the post-EBG vs pre-EBG cohorts (log-rank P < 0.01). There were trends toward faster time to MAS-HLH diagnosis, faster initiation of immunosuppressive therapy, shorter length of hospital stay, and more rapid normalization of MAS-HLH-related biomarkers in the patients post-EBG.

CONCLUSION

While the observed improvements may be partially attributed to advances in treatment of MAS-HLH that have accumulated over time, this analysis also suggests that a multidisciplinary treatment pathway for MAS-HLH contributed meaningfully to favorable patient outcomes.

Sepsis and Thrombocytopenia: A Nowadays Problem

Sepsis is a life-threatening organ failure produced by a dysregulated host response to infection that involves 15.6% of hospital mortality. The most common signs and symptoms of sepsis are hypotension, tachypnea, fever, and leukocytosis, whether suspected or confirmed. Including a major one, thrombocytopenia is a sign that is an independent predictor of poor outcomes in patients with sepsis, increasing their mortality rate and their length of stay in the intensive care unit (ICU). So far, the ongoing treatment for this problem is securing the airway, treating hypoxemia, and providing vascular access for hydration, antibiotic delivery, and vasopressors, if needed. This article has reviewed the different possible mechanisms found for sepsis-associated thrombocytopenia, going from the most acknowledged one as decreased platelet production to the potential aftermath of sepsis itself as disseminated intravascular coagulation (DIC). This article has also discussed the future treatment for patients suffering from thrombocytopenia and sepsis, going from phase I and II trials as GI antagonists to the well-known drug aspirin as a possible treatment for this problem.

Adapted Murine Sepsis Score: Improving the Research in Experimental Sepsis Mouse Model

The Murine Sepsis Score (MSS) is used to assess the severity of sepsis in rats and mice based on observational characteristics. The quantitative variables of glycemia, body weight, and temperature are predictors of severity in experimental models of sepsis. Therefore, our study sought to adapt the MSS with the same variables to indicate earlier the severity of the disease in murine models of the disease. Sepsis mice presented hypoglycemia, weight loss, and hypothermia. Therefore, these variables were included in the Adapted Murine Sepsis Score (A-MSS). The A-MASS presented 100% specificity and 87.5% sensibility been able to differentiate the early sepsis symptoms and its severity. The A-MSS allows an early and more complete diagnosis of sepsis in mice and might be considered as a procedure to improve the analysis of systemic sepsis dysfunction in murine experimental models.

Platelets in pediatric and neonatal sepsis: novel mediators of the inflammatory cascade

Sepsis, a dysregulated host response to infection, has been difficult to accurately define in children. Despite a higher incidence, especially in neonates, a non-specific clinical presentation alongside a lack of verified biomarkers has prevented a common understanding of this condition. Platelets, traditionally regarded as mediators of haemostasis and thrombosis, are increasingly associated with functions in the immune system with involvement across the spectrum of innate and adaptive immunity. The large number of circulating platelets (approx. 150,000 cells per microlitre) mean they outnumber traditional immune cells and are often the first to encounter a pathogen at a site of injury. There are also well-described physiological differences between platelets in children and adults. The purpose of this review is to place into context the platelet and its role in immunology and examine the evidence where available for its role as an immune cell in childhood sepsis. It will examine how the platelet interacts with both humoral and cellular components of the immune system and finally discuss the role the platelet proteome, releasate and extracellular vesicles may play in childhood sepsis. This review also examines how platelet transfusions may interfere with the complex relationships between immune cells in infection. IMPACT: Platelets are increasingly being recognised as important "first responders" to immune threats. Differences in adult and paediatric platelets may contribute to differing immune response to infections. Adult platelet transfusions may affect infant immune responses to inflammatory/infectious stimuli.

Secondary Hemophagocytic Lymphohistiocytosis in Post-COVID-19 Patients: A Report of Two Cases

Hemophagocytic lymphohistiocytosis (HLH) is a disease that can affect both children and adults. HLH can be categorized as primary or secondary. Secondary HLH (sHLH) may be secondary to various viral infections. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus infection is a pandemic with multi-system involvement. HLH in COVID-19 positive patients is a recognized entity. However, in post-COVID-19 patients who have recovered and are negative by serological tests and reverse transcription-polymerase chain reaction test may present with sHLH due to dysregulation of the immune system. We highlight this unusual finding of post-COVID-19 sHLH in two cases, who were diagnosed by the new revised H-score.

Relative platelet reductions provide better pathophysiologic signatures of coagulopathies in sepsis

In sepsis-associated coagulopathies and disseminated intravascular coagulation, relative platelet reductions may reflect coagulopathy severity. However, limited evidence supports their clinical significance and most sepsis-associated coagulopathy criteria focus on the absolute platelet counts. To estimate the impact of relative platelet reductions and absolute platelet counts on sepsis outcomes. A multicenter retrospective observational study was performed using the eICU Collaborative Research Database, comprising 335 intensive care units (ICUs) in the United States. Patients with sepsis and an ICU stay > 2 days were included. Estimated effects of relative platelet reductions and absolute platelet counts on mortality and coagulopathy-related complications were evaluated. Overall, 26,176 patients were included. Multivariate mixed-effect logistic regression analysis revealed marked in-hospital mortality risk with larger platelet reductions between days one and two, independent from the resultant absolute platelet counts. The adjusted odds ratio (OR) [95% confidence intervals (CI)] for in-hospital mortality was 1.28[1.23–1.32], 1.86[1.75–1.97], 2.99[2.66–3.36], and 6.05[4.40–8.31] for 20–40%, 40–60%, 60–80%, and > 80% reductions, respectively, when compared with a < 20% decrease in platelets (P < 0.001 for each). In the multivariate logistic regression analysis, platelet reductions ≥ 11% and platelet counts ≤ 100,000/μL on day 2 were associated with high coagulopathy-related complications (OR [95%CI], 2.03 and 1.18; P < 0.001 and P < 0.001), while only platelet reduction was associated with thromboembolic complications (OR [95%CI], 1.43 [1.03–1.98], P < 0.001). The magnitude of platelet reductions represent mortality risk and provides a better signature of coagulopathies in sepsis; therefore, it is a plausible criterion for sepsis-associated coagulopathies.

Coagulopathy and sepsis: Pathophysiology, clinical manifestations and treatment

Sepsis is a complex syndrome with a high incidence, increasing by 8.7% annually over the last 20 years. Coagulopathy is a leading factor associated with mortality in patients with sepsis and range from slight thrombocytopenia to fatal disorders, such as disseminated intravascular coagulation (DIC). Platelet reactivity increases during sepsis but prospective trials of antiplatelet therapy during sepsis have been disappointing. Thrombocytopenia is a known predictor of worse prognosis during sepsis. The mechanisms underlying thrombocytopenia in sepsis have yet to be fully understood but likely involves decreased platelet production, platelet sequestration and increased consumption. DIC is an acquired thrombohemorrhagic syndrome, resulting in intravascular fibrin formation, microangiopathic thrombosis, and subsequent depletion of coagulation factors and platelets. DIC can be resolved with treatment of the underlying disorder, which is considered the cornerstone in the management of this syndrome. This review presents the current knowledge on the pathophysiology, diagnosis, and treatment of sepsis-associated coagulopathies.

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.

Hemophagocytic Lymphohistiocytosis in Critically Ill Patients

BACKGROUND

Hemophagocytic lymphohistiocytosis (HLH), an uncontrolled overactivation of the immune system, is well characterized in pediatric patients, yet, much less is known about this life-threatening condition in adult patients. As HLH is often complicated by organ failure, patients will require admission to the intensive care unit for organ support therapy. However, recognition of HLH patients in the intensive care unit (ICU) is challenged by the clinical overlap with sepsis. Here, we analyze HLH patients to better understand its clinical presentation, diagnosis, and treatment.

METHODS

For the purpose of this retrospective observational study, we searched for suspected and diagnosed adult HLH of all patients admitted to at least one adult surgical, anesthesiological or medical ICU between January 2006 and August 2018 at the university hospital Charité - Universitätsmedizin Berlin. All cases were reviewed by two HLH experts, who confirmed or declined the diagnosis.

RESULTS

Of 6,340 ICU patients with ferritin measurement, 40 suffered from HLH (0.63%). Of these, in-hospital mortality was 60.0% over all cases, which was highest in malignancy-associated HLH (71.4%). Infections were identified as most common triggers (42.5%). A variety of 19 different treatment strategies were applied. Non-survivors showed higher ferritin at diagnosis compared with survivors (P = 0.021), which was also seen in multivariable analyses. A minimum ferritin of 4083 μg/L after diagnosis was most predictive for 30-day mortality (AUC 0.888, 95% CI 0.771-1.000; sensitivity 93.8%, specificity 78.9%).

CONCLUSIONS

Mortality in adult HLH patients in the ICU is high, particularly in malignancy-associated HLH. Infections are the most frequent HLH triggers in critically ill patients. At present, there is no standardized treatment for HLH in adult patients available. Assessment of ferritin is valuable for diagnosis, prognosis, and treatment monitoring.

TRIAL REGISTRATION

The study was registered with www.ClinicalTrials.gov (NCT02854943) on August 1, 2016.

Can Coagulation System Disorders and Cytokine and Inflammatory Marker Levels Predict the Temporary Clinical Deterioration or Improvement of Septic Patients on ICU Admission?

Although coagulation disorders and immune/inflammatory response have been associated with the final outcome of patients with sepsis, their link with thetemporaryclinical deterioration or improvement of patients is unknown. We aimed to investigate this link. We prospectively included consecutive patients admitted to the intensive care unit (ICU) with a suspected diagnosis of infection and evaluated within the first 24 h from admission. Blood levels of many cytokines and inflammatory and coagulation factors were measured and their predictive value was assessed by calculating the Area Under the Receiver Operating Characteristic (AUROC) curves. Patients (n = 102) were allocated in five groups, i.e., sepsis (n = 14), severe sepsis (n = 17), septic shock (n = 28), Systemic Inflammatory Response Syndrome (SIRS) without infection (n = 17), and trauma/surgery without SIRS or infection (n = 26). In septic shock, coagulation factors FVII and FIX and Protein C had AUROCs 0.67-0.78. In severe sepsis, Antithrombin III, Protein C, C-reactive protein, Procalcitonin and Thrombopoietin had AUROCs 0.73-0.75. In sepsis, Tumor Necrosis Factor a, and Interleukins 1β and 10 had AUROCs 0.66-0.72. In patients admitted to the ICU with a suspected diagnosis of infection, coagulation factors and inhibitors, as well as cytokine and inflammatory marker levels, have substantial predictive value in distinct groups of septic patients.

Can we truly diagnose adult secondary hemophagocytic lymphohistiocytosis (HLH)? A critical review of current paradigms

The HLH-2004 criteria were initially conceived as inclusion criteria for a clinical trial investigating therapy for (largely primary) pediatric hemophagocytic lymphohistiocytosis (HLH). These criteria have since been extrapolated to diagnose adult secondary HLH despite their questionable generalizability. It remains unclear whether these diagnostic criteria are truly applicable among adult secondary cases, and rigorous evidence for their use among such patients is lacking. This review critically examines the utility of the HLH-2004 criteria for the diagnosis of adult secondary HLH. It is framed as a reappraisal of each of the criteria's individual components, with an assessment of the relevance of, and/or evidence regarding, each. There are clear limitations to these criteria as they apply to adult secondary HLH, however they may help guide our understanding of the disease to some extent. Some new paradigms are emerging for the diagnosis of adult secondary HLH, however these too are limited by the difficulties inherent in formulating specific criteria for a very non-specific syndrome, which lacks any single gold-standard diagnostic test.

Current understanding and future implications of sepsis-induced thrombocytopenia

Sepsis is a global health burden that needs intensive medical care. Thrombocytopenia in sepsis is well known to increase morbidity as well as mortality. Several studies have been performed both in animal models and in humans to understand the mechanism by which sepsis causes thrombocytopenia. Recent studies have shown that inhibiting thrombocytopenia improves outcomes in sepsis patients. Understanding these mechanisms to identify targets in use of newer treatment modalities besides using resuscitation measures, antibiotics and removal of thrombocytopenia inducing agent could potentially help us improve outcomes in sepsis.

Umbilical Cord-Derived CD362+ Mesenchymal Stromal Cells Attenuate Polymicrobial Sepsis Induced by Caecal Ligation and Puncture

Mesenchymal stromal cells (MSCs) have a multimodal, immunomodulatory mechanism of action and are now in clinical trials for single organ and systemic sepsis. However, a number of practicalities around source, homogeneity and therapeutic window remain to be determined. Here, we utilised conditioned medium from CD362⁺-sorted umbilical cord-human MSCs (UC-hMSCs) for a series of in vitro anti-inflammatory assays and the cryopreserved MSCs themselves in a severe (Series 1) or moderate (Series 2+3) caecal ligation and puncture (CLP) rodent model. Surviving animals were assessed at 48 h post injury induction. MSCs improved human lung, colonic and kidney epithelial cell survival following cytokine activation. In severe systemic sepsis, MSCs administered at 30 min enhanced survival (Series 1), and reduced organ bacterial load. In moderate systemic sepsis (Series 2), MSCs were ineffective when delivered immediately or 24 h later. Of importance, MSCs delivered 4 h post induction of moderate sepsis (Series 3) were effective, improving serum lactate, enhancing bacterial clearance from tissues, reducing pro-inflammatory cytokine concentrations and increasing antimicrobial peptides in serum. While demonstrating benefit and immunomodulation in systemic sepsis, therapeutic efficacy may be limited to a specific point of disease onset, and repeat dosing, MSC enhancement or other contingencies may be necessary.

Title: Cytokine release syndrome is not usually caused by secondary hemophagocytic lymphohistiocytosis in a cohort of 19 critically ill COVID-19 patients

Severe COVID-19 associated respiratory failure, poses the one challenge of our days. Assessment and treatment of COVID-19 associated hyperinflammation may be key to improve outcomes. It was speculated that in subgroups of patients secondary hemophagocytic lymphohistiocytosis (sHLH) or cytokine release syndrome (CRS) with features of macrophage activation syndrome might drive severe disease trajectories. If confirmed, profound immunosuppressive therapy would be a rationale treatment approach. Over a median observation period of 11 (IQR: 8; 16) days, 19 consecutive confirmed severe COVID-19-patients admitted to our intensive-care-unit were tested for presence of sHLH by two independent experts. HScores and 2004-HLH diagnostic criteria were assessed. Patients were grouped according to short-term clinical courses: discharge from ICU versus ongoing ARDS or death at time of analysis. The median HScore at admission was 157 (IQR: 98;180), without the key clinical triad of HLH, i.e. progressive cytopenia, persistent fever and organomegaly. Independent expert chart review revealed the absence of sHLH in all cases. No patient reached more than 3/6 of modified HLH 2004 criteria. Nevertheless, patients presented hyperinflammation with peripheral neutrophilic signatures (neutrophil/lymphocyte-ratio > 3.5). The latter best paralleled their short-term clinical courses, with declining relative neutrophil numbers prior to extubation (4.4, [IQR: 2.5;6.3]; n = 8) versus those with unfavourable courses (7.6, [IQR: 5.2;31], n = 9). Our study rules out virus induced sHLH as the leading cause of most severe-COVID-19 trajectories. Instead, an associated innate neutrophilic hyperinflammatory response or virus-associated-CRS appears dominant in patients with an unfavourable clinical course. Therapeutic implications are discussed.

Immunosuppression is Inappropriately Qualifying the Immune Status of Septic and SIRS Patients

Immunosuppression is the most commonly used concept to qualify the immune status of patients with either sterile systemic inflammatory response syndrome (SIRS) or sepsis. In this review we attempt to demonstrate that the concept of immunosuppression is an oversimplification of the complex anti-inflammatory response that occurs in patients dealing with a severe sterile or infectious insult. Particularly, the immune status of leukocytes varies greatly depending on the compartment from where they are derived from. Furthermore, although certain functions of immune cells present in the blood stream or in the hematopoietic organs can be significantly diminished, other functions are either unchanged or even enhanced. This juxtaposition illustrates that there is no global defect. The mechanisms called reprogramming or trained innate immunity are probably aimed at preventing a generalized deleterious inflammatory reaction, and work to maintain the defense mechanisms at their due levels.

Macrophage Activation Syndrome and Secondary Hemophagocytic Lymphohistiocytosis in Childhood Inflammatory Disorders: Diagnosis and Management

Macrophage activation syndrome (MAS), a form of secondary hemophagocytic lymphohistiocytosis, is a frequently fatal complication of a variety of pediatric inflammatory disorders. MAS has been most commonly associated with systemic juvenile idiopathic arthritis (sJIA), as approximately 10% of children with sJIA develop fulminant MAS, with another 30-40% exhibiting a more subclinical form of the disease. Children with other rheumatologic conditions such as systemic lupus erythematosus and Kawasaki disease are also at risk for MAS. Moreover, MAS also complicates various genetic autoinflammatory disorders such as gain of function mutations in the cytosolic inflammasome NLRC4, pediatric hematologic malignancies (e.g., T-cell lymphoma), and primary immunodeficiencies characterized by immune dysregulation. Disease-specific and broadly inclusive diagnostic criteria have been developed to facilitate the diagnosis of MAS. Recently, simple screening tools such as the serum ferritin to erythrocyte sedimentation rate ratio have been proposed. Early diagnosis and rapid initiation of immunosuppression are essential for the effective management of MAS. With a better understanding of the pathophysiology of MAS and the advent of novel therapeutics, a broad immunosuppressive approach to treatment is giving way to targeted anti-cytokine therapies. These treatments include agents that block interleukin-1 (IL-1), IL-6, IL-18, interferon-γ, as well as inhibitors of downstream targets of cytokine signaling (e.g., Janus kinases). Increased early recognition of MAS among pediatric inflammatory disorders combined with the use of effective and less toxic cytokine-targeted therapies should lower the mortality of this frequently fatal disorder.

Haemophagocytic lymphohistiocytosis in adult critical care

Haemophagocytic lymphohistiocytosis (HLH) is a syndrome of severe immune dysregulation, characterised by extreme inflammation, fever, cytopaenias and organ dysfunction. HLH can be triggered by conditions such as infection, autoimmune disease and malignancy, among others. Both a familial and a secondary form have been described, the latter being increasingly recognised in adult patients with critical illness. HLH is difficult to diagnose, often under-recognised and carries a high mortality. Patients can present in a very similar fashion to sepsis and the two syndromes can co-exist and overlap, yet HLH requires specific immunosuppressive therapy. HLH should be actively excluded in patients with presumed sepsis who either lack a clear focus of infection or who are not responding to energetic infection management. Elevated serum ferritin is a key biomarker that may indicate the need for further investigations for HLH and can guide treatment. Early diagnosis and a multidisciplinary approach to HLH management may save lives.

Hepatic sinusoidal hemophagocytosis with and without hemophagocytic lymphohistiocytosis

BACKGROUND/PURPOSE

Hemophagocytic lymphohistiocytosis (HLH) is a rare, life threatening hyperinflammatory syndrome. Sinusoidal hemophagocytosis is occasionally observed on liver biopsy in patients who do not have clinical suspicion of HLH. We aimed at comparing the clinical characteristics and outcomes of patients with signs of hemophagocytosis on liver biopsy meeting and not meeting the HLH diagnostic criteria.

METHODS

We reviewed the clinical, laboratory features and outcomes of all adult patients consecutively admitted in our center between 08/2011 and 08/2017 presenting with liver histology showing sinusoidal hemophagocytosis and of critically ill patients presenting with severe liver disease in whom hemophagocytosis was histologically confirmed. The characteristics of patients fulfilling and not fulfilling the diagnostic criteria of HLH were compared.

RESULTS

We identified 12 cases (58% male, median age 61, 75% with a chronic underlying disease) with liver histology showing sinusoidal hemophagocytosis. All had at least some of the clinical features typically associated with HLH. Six were critical ill patients. In 4 cases with insufficient laboratory and clinical criteria, liver biopsy allowed to confirm the HLH diagnosis. Six patients died, of which four met the diagnostic criteria for HLH. Two patients with chronic liver disease died despite not fulfilling the diagnostic criteria of HLH.

CONCLUSION

Hemophagocytosis on liver biopsy may contribute to confirming a diagnosis of HLH in suspected cases with indeterminate clinical and laboratory findings. Sinusoidal hemophagocytosis in patients with cirrhosis was associated with bad outcome.

The Use of High Dose Eltrombopag in the Management of Sepsis-Associated Thrombocytopenia in Critically Ill Patients

Introduction

Sepsis is a life-threatening condition, and sepsis-associated thrombocytopenia (SAT) is a common consequence of the disease where platelet count falls drastically within a very short time. Multiple key factors may cause platelet over-activation, destruction and reduction in platelet production during the sepsis. Eltrombopag is a thrombopoietin receptor agonist and is the second-line drug of choice in the treatment of chronic immune thrombocytopenia (ITP).

Aim of the study

The objective of this study was to observe the therapeutic outcome of high dose eltrombopag in SAT management in critically ill patients.

Material and Methods

This 6-month-long single group, observational study was conducted on seventeen ICU patients with SAT. Eltrombopag 100 mg/day in two divided doses was given to each patient. Platelet counts were monitored. A low platelet blood count returning to 150 K/μL or above, is taken as indicative of a successful reversal of a thrombocytopenia event.

Results

The mean Apache II score of patients (n= 17) was 18.71 (p-value: >0.05). No eltrombopag-induced adverse event was observed among the patients during the study period. Thrombocytopenia events were reversed successfully in 64.71% of patients (11; n= 17) within eight days of eltrombopag therapy.

Conclusions

The therapeutic potentiality of high dose eltrombopag regime in the management of sepsis-associated thrombocytopenia was found clinically significant in over two-thirds of critically ill adult patients enrolled in the study. These data may point to a new strategy in the management of acute type of thrombocytopenia in septic patients.

Mechanisms of Thrombocytopenia During Septic Shock: A Multiplex Cluster Analysis of Endogenous Sepsis Mediators

BACKGROUND

Thrombocytopenia is a common feature of sepsis and may involve various mechanisms often related to the inflammatory response. This study aimed at evaluating factors associated with thrombocytopenia during human septic shock. In particular, we used a multiplex analysis to assess the role of endogenous sepsis mediators.

METHODS

Prospective, observational study. Thrombocytopenia was defined as an absolute platelet count <100 G/L or a 50% relative decrease in platelet count during the first week of septic shock. Plasma concentrations of 27 endogenous mediators involved in sepsis and platelet pathophysiology were assessed at day-1 using a multi-analyte Milliplex human cytokine kit. Patients with underlying diseases at risk of thrombocytopenia (hematological malignancies, chemotherapy, cirrhosis, and chronic heart failure) were excluded.

RESULTS

Thrombocytopenia occurred in 33 (55%) of 60 patients assessed. Patients with thrombocytopenia were more prone to present with extrapulmonary infections and bacteremia. Disseminated intravascular coagulation was frequent (81%) in these patients. Unbiased hierarchical clustering identified five different clusters of sepsis mediators, including one with markers of platelet activation (e.g., thrombospondin-1) positively associated with platelet count, one with markers of inflammation (e.g., tumor necrosis factor alpha and heat shock protein 70), and endothelial dysfunction (e.g., intercellular adhesion molecule-1 and vascular cell adhesion molecule-1) negatively associated with platelet count, and another involving growth factors of thrombopoiesis (e.g., thrombopoietin), also negatively associated with platelet count. Surrogates of hemodilution (e.g., hypoprotidemia and higher fluid balance) were also associated with thrombocytopenia.

CONCLUSION

Multiple mechanisms seemed involved in thrombocytopenia during septic shock, including endothelial dysfunction/coagulopathy, hemodilution, and altered thrombopoiesis.

Pneumococcal Bacteremia Complicated by Hemophagocytic Lymphohistiocytosis

From pneumonia to pericarditis, from sepsis to splenic abscess, Streptococcus pneumoniae is the causative agent of a diverse array of pyogenic disease. With the introduction of vaccines and effective antibiotic treatments, the incidence of complicated streptococcal infection has declined. We report a case of S. pneumoniae bacteremia, in the setting of occult sinusitis, complicated by hemophagocytic lymphohistiocytosis (HLH), disseminated intravascular coagulation (DIC), and recurrent pneumococcal infection. Although severe streptococcal infection has been associated with immunodeficiency or splenectomy, no such predisposition was identified in our patient. We discuss the association of streptococcal infection with HLH and DIC and review occult sinusitis as a source of pneumococcal bacteremia, with the goal of enhancing the "illness scripts" of general medical practitioners to include such entities.

Platelets in Sepsis: An Update on Experimental Models and Clinical Data

Beyond their important role in hemostasis, platelets play a crucial role in inflammatory diseases. This becomes apparent during sepsis, where platelet count and activation correlate with disease outcome and survival. Sepsis is caused by a dysregulated host response to infection, leading to organ dysfunction, permanent disabilities, or death. During sepsis, tissue injury results from the concomitant uncontrolled activation of the complement, coagulation, and inflammatory systems as well as platelet dysfunction. The balance between the systemic inflammatory response syndrome (SIRS) and the compensatory anti-inflammatory response (CARS) regulates sepsis outcome. Persistent thrombocytopenia is considered as an independent risk factor of mortality in sepsis, although it is still unclear whether the drop in platelet count is the cause or the consequence of sepsis severity. The role of platelets in sepsis development and progression was addressed in different experimental in vivo models, particularly in mice, that represent various aspects of human sepsis. The immunomodulatory function of platelets depends on the experimental model, time, and type of infection. Understanding the molecular mechanism of platelet regulation in inflammation could bring us one step closer to understand this important aspect of primary hemostasis which drives thrombotic as well as bleeding complications in patients with sterile and infectious inflammation. In this review, we summarize the current understanding of the contribution of platelets to sepsis severity and outcome. We highlight the differences between platelet receptors in mice and humans and discuss the potential and limitations of animal models to study platelet-related functions in sepsis.

Thrombocytopenia in Septic Shock Patients—A Prospective Observational Study of Incidence, Risk Factors and Correlation with Clinical Outcome

The objectives of the study were to study the incidence of various degrees of severity of thrombocytopenia in septic shock, the risk factors for its development and the correlation with clinical outcome. Complete blood counts, chemistry panel, arterial lactate, serum cortisol, APACHE II score, logistic organ dysfunction score and SOFA score were determined in 69 septic shock patients within 24 hours of admission or onset of septic shock. We followed the patients until they died or for six months to determine the mortality rate. The incidence of thrombocytopenia in our study group was 55%. Patients with thrombocytopenia had significantly higher serum creatinine, SOFA score, vasopressor requirement, lower PaO2/FiO2 ratio and higher mortality than those without thrombocytopenia (P <0.05). Higher SOFA score, low PaO2/FiO2 ratio and high vasopressor dose were independent risk factors for development of thrombocytopenia. The presence of thrombocytopenia had significant correlation with SOFA score (P=0.008). On receiver-operator characteristic curve analysis, platelet count was found to be predictive of increased mortality (area under curve=0.56). Thrombocytopenic patients had 1.4 times the risk of mortality and lower survival probability at six months (log rank test P=0.03). In conclusion, thrombocytopenia is common in septic shock and is associated with worse clinical outcome. Higher SOFA score, low PaO2/FiO2 ratio and high vasopressor dose are independent risk factors for development of thrombocytopenia in septic shock.

Complement Activation Occurs at the Surface of Platelets Activated by Streptococcal M1 Protein and This Results in Phagocytosis of Platelets

Platelets circulate the bloodstream and principally maintain hemostasis. Disturbed hemostasis, a dysregulated inflammatory state, and a decreased platelet count are all hallmarks of severe invasive Streptococcus pyogenes infection, sepsis. We have previously demonstrated that the released M1 protein from S. pyogenes activates platelets, and this activation is dependent on the binding of M1 protein, fibrinogen, and M1-specific IgG to platelets in susceptible donors. In this study, we characterize the M1-associated protein interactions in human plasma and investigate the acquisition of proteins to the surface of activated platelets and the consequences for platelet immune function. Using quantitative mass spectrometry, M1 protein was determined to form a protein complex in plasma with statistically significant enrichment of fibrinogen, IgG3, and complement components, especially C1q. Using flow cytometry, these plasma proteins were also confirmed to be acquired to the platelet surface, resulting in complement activation on M1-activated human platelets. Furthermore, we demonstrated an increased phagocytosis of M1-activated platelets by monocytes, which was not observed with other physiological platelet agonists. This reveals a novel mechanism of complement activation during streptococcal sepsis, which contributes to the platelet consumption that occurs in sepsis.

Pathogenesis and diagnosis of disseminated intravascular coagulation

Several clinical conditions, in particular those associated with a systemic inflammatory response, can cause some degree of activation of coagulation but when the procoagulant stimulus is sufficiently severe and overcomes the natural anticoagulant mechanisms of coagulation, disseminated intravascular coagulation (DIC) may occur. The clinical manifestations of DIC encompass multiorgan dysfunction caused by fibrin-platelet clots in the microcirculation, and bleeding caused by consumption of platelets and coagulation factors. Molecular mechanisms that play a role in inflammation-induced effects on coagulation have been recognized in much detail. Exposure of blood to tissue factor is the most common trigger, whereas the intravascular coagulation is propagated due to loss of function of physiological anticoagulants and impaired fibrinolysis. In patients with DIC, various abnormalities in routine coagulation parameters may be observed, including thrombocytopenia, prolonged global coagulation assays, or high levels of fibrin split products. In addition, more sophisticated tests for activation of individual factors or pathways of coagulation may point to specific involvement of these components in the pathogenesis of the disorder. A combination of readily available tests is usually sufficient in establishing the diagnosis of DIC, and for this purpose, several scoring algorithms have been developed. Some specific clinical situations may elicit coagulation responses that can be distinguished from DIC or may occur in combination with DIC, including dilutional coagulopathy, liver failure-related coagulation derangement, and thrombotic microangiopathies.

Disseminated intravascular coagulation: an update on pathogenesis and diagnosis

INTRODUCTION

Activation of the hemostatic system can occur in many clinical conditions. However, a systemic and strong activation of coagulation complicating clinical settings such as sepsis, trauma or malignant disease may result in the occurrence disseminated intravascular coagulation (DIC). Areas covered: This article reviews the clinical manifestation and relevance of DIC, the various conditions that may precipitate DIC and the pathogenetic pathways underlying the derangement of the hemostatic system, based on clinical and experimental studies. In addition, the (differential) diagnostic approach to DIC is discussed. Expert commentary: In recent years a lot of precise insights in the pathophysiology of DIC have been uncovered, leading to a better understanding of pathways leading to the hemostatic derangement and providing points of impact for better adjunctive treatment strategies. In addition, simple diagnostic algorithms have been developed and validated to establish a diagnosis of DIC in clinical practice.

Is There a Role for Hematopoietic Growth Factors During Sepsis?

Sepsis is a complex syndrome characterized by simultaneous activation of pro- and anti-inflammatory processes. After an inflammatory phase, patients present signs of immunosuppression and possibly persistent inflammation. Hematopoietic growth factors (HGFs) are glycoproteins that cause immune cells to mature and/or proliferate. HGFs also have a profound effect on cell functions and behavior. HGFs play crucial role in sepsis pathophysiology and were tested in several clinical trials without success to date. This review summarizes the role played by HGFs during sepsis and their potential therapeutic role in the Management of sepsis-related immune disturbances.

How I treat disseminated intravascular coagulation

Disseminated intravascular coagulation (DIC) is a condition characterized by systemic activation of coagulation, potentially leading to thrombotic obstruction of small and midsize vessels, thereby contributing to organ dysfunction. At the same time, ongoing consumption of platelets and coagulation proteins results in thrombocytopenia and low concentrations of clotting factors, which may cause profuse hemorrhagic complications. DIC is always secondary to an underlying condition, such as severe infections, solid or hematologic malignancies, trauma, or obstetric calamities. A reliable diagnosis of DIC can be made through simple scoring algorithms based on readily available routine hemostatic parameters. The cornerstone of supportive treatment of this coagulopathy is management of the underlying condition. Additionally, administration of heparin may be useful, and restoration of physiological anticoagulants has been suggested, but has not been proven successful in improving clinically relevant outcomes so far. In patients with major bleeding or at risk for hemorrhagic complications, administration of platelet concentrates, plasma, or coagulation factor concentrates should be considered.

Predicting 30-day mortality in patients with sepsis: An exploratory analysis of process of care and patient characteristics

Background

Sepsis represents a significant public health burden, costing the NHS £2.5 billion annually, with 35% mortality in 2006. The aim of this exploratory study was to investigate risk factors predictive of 30-day mortality amongst patients with sepsis in Nottingham.

Methods

Data were collected prospectively from adult patients with sepsis in Nottingham University Hospitals NHS Trust as part of an on-going quality improvement project between November 2011 and March 2014. Patients admitted to critical care with the diagnosis of sepsis were included in the study. In all, 97 separate variables were investigated for their association with 30-day mortality. Variables included patient demographics, symptoms of systemic inflammatory response syndrome, organ dysfunction or tissue hypoperfusion, locations of early care, source of sepsis and time to interventions.

Results

A total of 455 patients were included in the study. Increased age (adjOR = 1.05 95%CI = 1.03-1.07 p < 0.001), thrombocytopenia (adjOR = 3.10 95%CI = 1.23-7.82 p = 0.016), hospital-acquired sepsis (adjOR = 3.34 95%CI = 1.78-6.27 p < 0.001), increased lactate concentration (adjOR = 1.16 95%CI = 1.06-1.27 p = 0.001), remaining hypotensive after vasopressors (adjOR = 3.89 95%CI = 1.26-11.95 p = 0.02) and mottling (adjOR = 3.80 95%CI = 1.06-13.55 p = 0.04) increased 30-day mortality odds. Conversely, fever (adjOR = 0.46 95%CI = 0.28-0.75 p = 0.002), fluid refractory hypotension (adjOR = 0.29 95%CI = 0.10-0.87 p = 0.027) and being diagnosed in surgical wards (adjOR = 0.35 95%CI = 0.15-0.81 p = 0.015) were protective. Treatment timeliness were not significant factors.

Conclusion

Several important predictors of 30-day mortality were found by this research. Retrospective analysis of our sepsis data has revealed mortality predictors that appear to be more patient-related than intervention-specific. With this information, care can be improved for those identified most at risk of death.

Platelets directly regulate DNA damage and division of Staphylococcus aureus

Platelets (PLTs) are classically used in the clinical setting to maintain hemostasis. Recent evidence supports important roles for PLTs in host inflammatory and immune responses, and PLT-rich plasma has been demonstrated to inhibit the growth of bacteria in vitro and in vivo; however, few studies have examined whether PLTs can inhibit bacterial growth directly, and related mechanisms have not been elucidated further. Accordingly, in this study, we evaluated the effects of PLTs on bacterial growth. We washed and purified PLTs from peripheral blood, then confirmed that PLTs significantly inhibited the growth of Staphylococcus aureus when cocultured in vitro. Moreover, PLTs damaged DNA and blocked cell division in S. aureus. During coculture, PLT-derived TGF-β1 was dramatically down-regulated compared with that in PLT culture alone, and the addition of TGF-β1 to the coculture system promoted the inhibition of PLTs on S. aureus. Analysis of a murine S. aureus infection model demonstrated that the depletion of PLTs exacerbated the severity of infection, whereas the transfusion of PLTs alleviated this infection. Our observations demonstrate that PLTs could directly inhibit the growth of S. aureus by damaging DNA and blockage cell division, and that PLT-derived TGF-β1 may play an important role in this machinery.-Xu, J., Yi, J., Zhang, H., Feng, F., Gu, S., Weng, L., Zhang, J., Chen, Y., An, N., Liu, Z., An, Q., Yin, W., Hu, X. Platelets directly regulate DNA damage and division of Staphylococcus aureus.

Assessing thrombocytopenia in the intensive care unit: the past, present, and future

Thrombocytopenia is common among patients admitted to the intensive care unit (ICU). Multiple pathophysiological mechanisms may contribute, including thrombin-mediated platelet activation, dilution, hemophagocytosis, extracellular histones, ADAMTS13 deficiency, and complement activation. From the clinical perspective, the development of thrombocytopenia in the ICU usually indicates serious organ system derangement and physiologic decompensation rather than a primary hematologic disorder. Thrombocytopenia is associated with bleeding, transfusion, and adverse clinical outcomes including death, though few deaths are directly attributable to bleeding. The assessment of thrombocytopenia begins by looking back to the patient's medical history and presenting illness. This past information, combined with careful observation of the platelet trajectory in the context of the patient's clinical course, offers clues to the diagnosis and prognosis. Management is primarily directed at the underlying disorder and transfusion of platelets to prevent or treat clinical bleeding. Optimal platelet transfusion strategies are not defined, and a conservative approach is recommended.

Contribution to diagnosis and treatment of bone marrow aspirate results in critically ill patients undergoing bone marrow aspiration: a retrospective study of 193 consecutive patients

Background

The purpose of the work was to assess the contribution to diagnosis and/or treatment (CDT) of bone marrow aspiration (BMA) in the critically ill patient.

Methods

The retrospective study included 193 patients. On the basis of BMA findings, contribution to diagnosis was defined by one of four previously unestablished diagnoses (maturation arrest of granulocyte precursors, hemophagocytic lymphohistiocytosis, hematological malignancy, marrow infiltration with cancer cells) and to treatment as the initiation or withdrawal of a specific treatment including the decision to forgo life-sustaining treatment (DFLST).

Results

A CDT of BMA was observed in 40/193 patients (20.7%). BMA contributed to diagnosis in 37 cases (granulocyte precursor maturation arrest, N = 10; hemophagocytic lymphohistiocytosis, N = 12; hematological malignancy, N = 15) and to treatment in 14, including three DFLSTs. In multivariate analysis, the factors associated with a CDT were hematological malignancy, cancer or non-malignant hematological abnormality known on admission, indication for BMA excluding isolated thrombocytopenia, higher pre-BMA HScore (calculated prior to BMA), and higher SOFA score with or without platelet-count SOFA subscore. In the 160 patients without hematological malignancy or cancer known on admission, non-malignant hematological abnormality known on admission, indication for BMA excluding isolated thrombocytopenia, higher pre-BMA HScore, and higher SOFA score calculated with or without platelet-count SOFA subscore were independently associated with a CDT of BMA.

Conclusion

BMA can have a significant CDT in ICU patients with or without a known hematological malignancy or cancer on admission. An HScore calculated before BMA can be a valuable tool for predicting a CDT of BMA.

Electronic supplementary material

The online version of this article (10.1186/s40560-017-0263-7) contains supplementary material, which is available to authorized users.

New-onset acute thrombocytopenia in hospitalized patients: pathophysiology and diagnostic approach

Thrombocytopenia is a hematological finding commonly encountered in daily clinical practice from asymptomatic clinic patients to critically ill intensive care unit patients. A broad spectrum of etiologies and variation in clinical presentation often present a diagnostic challenge. Furthermore, concomitant presence of thrombosis and thrombocytopenia, as in cases of thrombotic thrombocytopenia, complicates the management. In hospitalized patients, new-onset thrombocytopenia is an important reason for hematology consultation. Therefore, it is of utmost importance that the etiology is diagnosed accurately. In addition, a basic understanding of the pathophysiology and the differential diagnosis avoids delay in the diagnosis and leads to rapid initiation of treatment. This review will address causes of thrombocytopenia that arises in hospitalized patients with an emphasis on the pathophysiological basis of each disorder.

The impact of admission neutrophil-to-platelet ratio on in-hospital and long-term mortality in patients with infective endocarditis

BACKGROUND

Infective endocarditis (IE) is associated with increased neutrophil and reduced platelet counts. We assessed the relationship between the neutrophil-to-platelet ratio (NPR) on admission and adverse outcomes in patients with IE.

METHODS

Patients diagnosed with IE between January 2009 and July 2015 (n=1293) were enrolled, and 1046 were finally entered into the study. Study subjects were categorized into four groups according to NPR quartiles: Q1<18.9 (n=260); Q2: 18.9-27.7 (n=258); Q3: 27.7-43.3 (n=266); and Q4>43.3 (n=262). Cox proportional hazards regression was performed to identify risk factors for long-term mortality; the optimal cut-off was evaluated by receiver operating characteristic curves.

RESULTS

Risk of in-hospital death increased progressively with NPR group number (1.9 vs. 5.0 vs. 9.8 vs. 14.1%, p<0.001). The follow-up period was a median of 28.8 months, during which 144 subjects (14.3%) died. Long-term mortality increased from the lowest to the highest NPR quartiles (7.6, 11.8, 17.4, and 26.2%, respectively, p<0.001). Multivariate Cox proportional hazard analysis revealed that lgNPR (HR=2.22) was an independent predictor of long-term mortality. Kaplan-Meier survival curves showed that subjects in Q4 had an increased long-term mortality compared with the other groups.

CONCLUSIONS

Increased NPR was associated with in-hospital and long-term mortality in patients with IE. As a simple and inexpensive index, NPR may be a useful and rapid screening tool to identify IE patients at high risk of mortality.

The Use of Ferritin to Identify Critically Ill Patients With Secondary Hemophagocytic Lymphohistiocytosis

OBJECTIVES

Thrombocytopenia is a common, multifactorial, finding in ICU. Hemophagocytosis is one of the main explanatory mechanisms, possibly integrated into hemophagocytic lymphohistiocytosis syndrome, of infectious origin in the majority of cases in ICU. The hemophagocytic lymphohistiocytosis is probably underdiagnosed in the ICU, although it is associated with dramatic outcomes. The main objectives of this work were to identify the frequency of secondary hemophagocytic lymphohistiocytosis, and the main prognostic factors for mortality.

DESIGN/SETTING

We conducted a retrospective observational study in all adult patients admitted with suspected or diagnosed hemophagocytic lymphohistiocytosis, between January 1, 2000, and August 22, 2012.

PATIENTS

A total of 106 patients (42%) had significant hemophagocytosis on bone marrow examination, performed for exploration of thrombocytopenia, bicytopenia, or pancytopenia.

MEASUREMENTS AND MAIN RESULTS

The median age was 56 (45-68) and the median Simplified Acute Physiology Score 2 was 55 (38-68). The main reason for ICU admission was hemodynamic instability (58%), predominantly related to sepsis (45% cases). The main precipitating factor found was a bacterial infection in 81 of 106 patients (76%), including 32 (30%) with Escherichia coli infection. Forty six of 106 patients (43%) died in the ICU. They were significantly older, had higher Simplified Acute Physiology Score 2, plasma lactate deshydrogenase bilirubin, and serum ferritin. The fibrinogen and the percentage of megakaryocytes were significantly lower in nonsurvivors when compared with survivors. In multivariate analysis, only serum ferritin significantly predicted death related to hemophagocytosis. A serum ferritin greater than 2,000 μg/L predicted death with a sensitivity of 71% and a specificity of 76%. A decreased percentage of megakaryocytes also predicted patient death in the ICU.

CONCLUSIONS

Hemophagocytosis is common in thrombocytopenic patients with sepsis, frequently included in a postinfectious hemophagocytic lymphohistiocytosis setting. Our study reveals that ferritin could be a reliable prognostic marker in these patients, and hold particular interest in discussing a specific treatment for hemophagocytic lymphohistiocytosis.