Disseminated intravascular coagulation and its immune mechanisms

Rapid high-throughput method for investigating physiological regulation of neutrophil extracellular trap formation

BACKGROUND

Neutrophils, the most abundant white blood cells in humans, play pivotal roles in innate immunity, rapidly migrating to sites of infection and inflammation to phagocytose, neutralize, and eliminate invading pathogens. Neutrophil extracellular trap (NET) formation is increasingly recognized as an essential rapid innate immune response, but when dysregulated, it contributes to pathogenesis of sepsis and immunothrombotic disease.

OBJECTIVES

Current NETosis models are limited, routinely employing nonphysiological triggers that can bypass natural NET regulatory pathways. Models utilizing isolated neutrophils and immortalized cell lines do not reflect the complex biology underlying neutrophil activation and NETosis that occurs in whole blood. To our knowledge, we report the first human ex vivo model utilizing naturally occurring molecules to induce NETosis in whole blood. This approach could be used for drug screening and, importantly, inadvertent activators of NETosis.

METHODS

Here we describe a novel, high-throughput ex vivo whole blood-induced NETosis model using combinatorial pooling of native NETosis-inducing factors in a more biologically relevant Synthetic-Sepsis model.

RESULTS

We found different combinations of factors evoked distinct neutrophil responses in the rate of NET generation and/or magnitude of NETosis. Despite interdonor variability, similar sets of proinflammatory molecules induced consistent responses across donors. We found that at least 3 biological triggers were necessary to induce NETosis in our system including either tumor necrosis factor-α or lymphotoxin-α.

CONCLUSION

These findings emphasize the importance of investigating neutrophil physiology in a biologically relevant context to enable a better understanding of disease pathology, risk factors, and therapeutic targets, potentially providing novel strategies for disease intervention and treatment.

COMPREHENSIVE THERAPEUTIC EFFICACY ANALYSIS OF INTRAVENOUS IMMUNOGLOBULIN IN TREATING SEPSIS-INDUCED COAGULOPATHY: A SINGLE-CENTER, RETROSPECTIVE OBSERVATIONAL STUDY

ABSTRACT

Objective : The aim of the study is to investigate the efficacy of intravenous immunoglobulin (IVIg) in treating sepsis-induced coagulopathy ( SIC ). Methods : A retrospective controlled analysis was conducted on 230 patients with SIC at Ganzhou People's Hospital from January 2016 to December 2022. All patients were screened using propensity score matching and treated according to the SSC2016 guidelines. Compared with the control group (n = 115), patients in the test group (n = 115) received IVIg (200 mg/kg.d) for 3 consecutive days after admission. The rating scales, coagulation function, survival, and treatment duration were evaluated. Results : On day 3 of treatment, both groups exhibited reduced platelet and thromboelastogram (TEG) maximum amplitude (MA) levels, with the control group showing a more significant decrease ( P < 0.05). By the fifth day, these levels had recovered in both groups. However, the test group experienced a significant increase by day 7 ( P < 0.05). Coagulation factors II and X began to increase on day 3, and normalization was significantly faster in the test group on day 5 ( P < 0.05). The levels of prothrombin time, international normalized ratio, activated partial thromboplastin time, d -dimer, fibrinogen, fibrin degradation products, TEG-R, and TEG-K exhibited a notable decline on day 3 and demonstrated significantly faster recovery on day 5 in the test group ( P < 0.05). In addition, both groups showed a reduction in Acute Physiology and Chronic Health Evaluation II, Sequential Organ Failure Assessment, disseminated intravascular coagulation, and lactate (LAC) levels on day 3, but the test group's scores decreased significantly more by day 7 ( P < 0.05). Within the test group, white blood cell count, C-reactive protein, procalcitonin, IL-6, and Tmax levels were lower ( P < 0.05). Furthermore, the test group demonstrated shorter duration for intensive care unit stay, mechanical ventilation, and continuous renal replacement therapy ( P < 0.05). No significant differences were observed in the duration of fever or vasoactive drug use between the groups. However, the log-rank method indicated a higher 28-day survival rate in the test group ( P < 0.05). Conclusion : IVIg can successfully increase platelet count and coagulation factors, correct coagulation disorders, enhance organ function, and reduce 28-day mortality in patients with SIC .

Targeting extranuclear histones to alleviate acute and chronic inflammation

Extracellular histones instigate an inflammatory triad - centered on cytotoxicity, immune cell stimulation, and coagulation - ultimately shaping the dynamics and outcome of various inflammatory pathologies. Given the virtual absence of beneficial functions of histones in the extracellular space, in recent years a number of interference strategies have emerged. In this review we summarize pathogenic functions of extracellular histones and highlight current developments of therapeutic interference. Finally, we elaborate on the current status of preclinical attempts to interfere with extracellular histones in the context of a focus on sepsis and cardiovascular diseases, both of which are leading causes of mortality worldwide.

Immunological alterations in the endothelial barrier: a new predictive and therapeutic paradigm for sepsis

INTRODUCTION

Despite the fact incidence and mortality vary widely among regions, sepsis remains a major cause of morbidity and cost worldwide. The importance of the endothelial barrier in sepsis and infectious diseases is increasingly recognized; however, the underlying pathophysiology of the endothelial barrier in sepsis remains poorly understood.

AREAS COVERED

Here we review the advances in basic and clinical research for relevant papers in PubMed database. We attempt to provide an updated overview of immunological alterations in endothelial dysfunction, discussing the central role of endothelial barrier involved in sepsis to provide new predictive and therapeutic paradigm for sepsis.

EXPERT OPINION

Given its physiological and immunological functions in infectious diseases, the endothelial barrier has been dramatically altered in sepsis, suggesting that endothelial dysfunction may play a critical role in the pathogenesis of sepsis. Although many reliable biomarkers have been investigated to monitor endothelial activation and injury in an attempt to find diagnostic and therapeutic tools, there are no specific therapies to treat sepsis due to its complex pathophysiology. Since sepsis is initiated by both hyperinflammation and immunoparalysis occurring simultaneously, a 'one-treatment-fits-all' strategy for sepsis-induced immune injury and immunoparalysis is bound to fail, and an individualized 'precision medicine' approach is required.

Macrophage fate: to kill or not to kill?

Macrophages are dynamic innate immune cells that either reside in tissue, serving as sentinels, or recruited as monocytes from bone marrow into inflamed and infected tissue. In response to cues in the tissue microenvironment (TME), macrophages polarize on a continuum toward M1 or M2 with diverse roles in progression and resolution of disease. M1-like macrophages exhibit proinflammatory functions with antimicrobial and anti-tumorigenic activities, while M2-like macrophages have anti-inflammatory functions that generally resolve inflammatory responses and orchestrate a tissue healing process. Given these opposite phenotypes, proper spatiotemporal coordination of macrophage polarization in response to cues within the TME is critical to effectively resolve infectious disease and regulate wound healing. However, if this spatiotemporal coordination becomes disrupted due to persistent infection or dysregulated coagulation, macrophages' inappropriate response to these cues will result in the development of diseases with clinically unfavorable outcomes. Since plasticity and heterogeneity are hallmarks of macrophages, they are attractive targets for therapies to reprogram toward specific phenotypes that could resolve disease and favor clinical prognosis. In this review, we discuss how basic science studies have elucidated macrophage polarization mechanisms in TMEs during infections and inflammation, particularly coagulation. Therefore, understanding the dynamics of macrophage polarization within TMEs in diseases is important in further development of targeted therapies.

Schistocyte detection in artificial intelligence age

Schistocytes are fragmented red blood cells produced as a result of mechanical damage to erythrocytes, usually due to microangiopathic thrombotic diseases or mechanical factors. The early laboratory detection of schistocytes has a critical impact on the timely diagnosis, effective treatment, and positive prognosis of diseases such as thrombocytopenic purpura and hemolytic uremic syndrome. Due to the rapid development of science and technology, laboratory hematology has also advanced. The accuracy and efficiency of tests performed by fully automated hematology analyzers and fully automated morphology analyzers have been considerably improved. In recent years, substantial improvements in computing power and machine learning (ML) algorithm development have dramatically extended the limits of the potential of autonomous machines. The rapid development of machine learning and artificial intelligence (AI) has led to the iteration and upgrade of automated detection of schistocytes. However, along with significantly facilitated operation processes, AI has brought challenges. This review summarizes the progress in laboratory schistocyte detection, the relationship between schistocytes and clinical diseases, and the progress of AI in the detection of schistocytes. In addition, current challenges and possible solutions are discussed, as well as the great potential of AI techniques for schistocyte testing in peripheral blood.

Unraveling the Intricate Web: Complement Activation Shapes the Pathogenesis of Sepsis-Induced Coagulopathy

BACKGROUND

Sepsis-associated coagulopathy specifically refers to widespread systemic coagulation activation accompanied by a high risk of hemorrhage and organ damage, which in severe cases manifests as disseminated intravascular coagulation (DIC), or even develops into multiple organ dysfunction syndrome (MODS). The complement system and the coagulation system as the main columns of innate immunity and hemostasis, respectively, undergo substantial activation after sepsis.

SUMMARY

Dysfunction of the complement, coagulation/fibrinolytic cascades caused by sepsis leads to "thromboinflammation," which ultimately amplifies the systemic inflammatory response and accelerates the development of MODS. Recent studies have revealed that massive activation of the complement system exacerbates sepsis-induced coagulation and even results in DIC, which suggests that inhibition of complement activation may have therapeutic potential in the treatment of septic coagulopathy.

KEY MESSAGES

Sepsis-associated thrombosis involves the upregulation or activation of procoagulant factors, down-regulation or inactivation of anticoagulant factors, and impairment of the fibrinolytic mechanism. This review aims to summarize the latest literature and analyze the underlying molecular mechanisms of the activation of the complement system on the abnormal coagulation cascades in sepsis.

Deciphering Abnormal Platelet Subpopulations in COVID-19, Sepsis and Systemic Lupus Erythematosus through Machine Learning and Single-Cell Transcriptomics

This study focuses on understanding the transcriptional heterogeneity of activated platelets and its impact on diseases such as sepsis, COVID-19, and systemic lupus erythematosus (SLE). Recognizing the limited knowledge in this area, our research aims to dissect the complex transcriptional profiles of activated platelets to aid in developing targeted therapies for abnormal and pathogenic platelet subtypes. We analyzed single-cell transcriptional profiles from 47,977 platelets derived from 413 samples of patients with these diseases, utilizing Deep Neural Network (DNN) and eXtreme Gradient Boosting (XGB) to distinguish transcriptomic signatures predictive of fatal or survival outcomes. Our approach included source data annotations and platelet markers, along with SingleR and Seurat for comprehensive profiling. Additionally, we employed Uniform Manifold Approximation and Projection (UMAP) for effective dimensionality reduction and visualization, aiding in the identification of various platelet subtypes and their relation to disease severity and patient outcomes. Our results highlighted distinct platelet subpopulations that correlate with disease severity, revealing that changes in platelet transcription patterns can intensify endotheliopathy, increasing the risk of coagulation in fatal cases. Moreover, these changes may impact lymphocyte function, indicating a more extensive role for platelets in inflammatory and immune responses. This study identifies crucial biomarkers of platelet heterogeneity in serious health conditions, paving the way for innovative therapeutic approaches targeting platelet activation, which could improve patient outcomes in diseases characterized by altered platelet function.

Acute cardiovascular complications of disseminated intravascular coagulation in acute myeloid leukemia

BACKGROUND

Disseminated intravascular coagulation (DIC) is a common complication of all leukemia subtypes, but it is an especially prominent feature of Acute Myeloid Leukemias (AML). DIC complicating AML can lead to a variety of complications, however, its association with acute cardiovascular complications has not been reported before.

METHODS

National Inpatient Sample Database was used to procure individuals with AML, and baseline demographics and comorbidities were collected using ICD-10-DM codes. Patients were stratified into those with and without DIC. Greedy propensity matching using R was performed to match the two cohorts in 1:1 ratio on age, gender, and fifteen other baseline comorbidities. Univariate analysis pre and post-match along with binary logistic regression analysis post-match were used to analyze outcomes.

RESULTS

Out of a total of 37,344 patients with AML, 996 had DIC. DIC patients were younger, predominantly males, and had lower prevalence of baseline cardiovascular comorbidities. DIC patients had statistically significant higher mortality (30.2 % vs 7.8 %), acute myocardial infarction (5.1 % vs 1.8 %), acute pulmonary edema (2.3 % vs 0.7 %), cardiac arrest (6.4 % vs 0.9 %), and acute DVT/PE (6.6 % vs 2.7 %). Logistic regression model after matching showed similar outcomes along with significantly higher rates of acute heart failure in DIC patients.

CONCLUSION

These findings highlight the importance of close cardiovascular monitoring and prompt recognition of complications in AML patients with DIC. The underlying mechanisms involve a complex interplay of procoagulant factors, cytokine release, and endothelial dysfunction. Further studies are needed to develop targeted interventions for prevention and management of these complications.

Damage-associated cellular markers in the clinical and pathogenic profile of vaccine-induced immune thrombotic thrombocytopenia

BACKGROUND

Adenoviral vector-based COVID-19 vaccine-induced immune thrombotic thrombocytopenia (VITT) is rare but carries significant risks of mortality and long-term morbidity. The underlying pathophysiology of severe disease is still not fully understood. The objectives were to explore the pathophysiological profile and examine for clinically informative biomarkers in patients with severe VITT.

METHODS

Twenty-two hospitalized patients with VITT, 9 pre- and 21 post-ChAdOx1 vaccine controls, were recruited across England, United Kingdom. Admission blood samples were analyzed for cytokine profiles, cell death markers (lactate dehydrogenase and circulating histones), neutrophil extracellular traps, and coagulation parameters. Tissue specimens from deceased patients were analyzed.

RESULTS

There were strong immune responses characterized by significant elevations in proinflammatory cytokines and T helper 1 and 2 cell activation in patients with VITT. Markers of systemic endothelial activation and coagulation activation in both circulation and organ sections were also significantly elevated. About 70% (n = 15/22) of patients met the International Society for Thrombosis and Haemostasis criteria for disseminated intravascular coagulation despite negligible changes in the prothrombin time. The increased neutrophil extracellular trap formation, in conjunction with marked lymphopenia, elevated lactate dehydrogenase, and circulating histone levels, indicates systemic immune cell injury or death. Both lymphopenia and circulating histone levels independently predicted 28-day mortality in patients with VITT.

CONCLUSION

The coupling of systemic cell damage and death with strong immune-inflammatory and coagulant responses are pathophysiologically dominant and clinically relevant in severe VITT.

Low-frequency inherited complement receptor variants are associated with purpura fulminans

ABSTRACT

Extreme disease phenotypes can provide key insights into the pathophysiology of common conditions, but studying such cases is challenging due to their rarity and the limited statistical power of existing methods. Herein, we used a novel approach to pathway-based mutational burden testing, the rare variant trend test (RVTT), to investigate genetic risk factors for an extreme form of sepsis-induced coagulopathy, infectious purpura fulminans (PF). In addition to prospective patient sample collection, we electronically screened over 10.4 million medical records from 4 large hospital systems and identified historical cases of PF for which archived specimens were available to perform germline whole-exome sequencing. We found a significantly increased burden of low-frequency, putatively function-altering variants in the complement system in patients with PF compared with unselected patients with sepsis (P = .01). A multivariable logistic regression analysis found that the number of complement system variants per patient was independently associated with PF after controlling for age, sex, and disease acuity (P = .01). Functional characterization of PF-associated variants in the immunomodulatory complement receptors CR3 and CR4 revealed that they result in partial or complete loss of anti-inflammatory CR3 function and/or gain of proinflammatory CR4 function. Taken together, these findings suggest that inherited defects in CR3 and CR4 predispose to the maladaptive hyperinflammation that characterizes severe sepsis with coagulopathy.

Phenotypes of Disseminated Intravascular Coagulation

Two phenotypes of disseminated intravascular coagulation (DIC) are systematically reviewed. DIC is classified into thrombotic and fibrinolytic phenotypes characterized by thrombosis and hemorrhage, respectively. Major pathology of DIC with thrombotic phenotype is the activation of coagulation, insufficient anticoagulation with endothelial injury, and plasminogen activator inhibitor-1-mediated inhibition of fibrinolysis, leading to microvascular fibrin thrombosis and organ dysfunction. DIC with fibrinolytic phenotype is defined as massive thrombin generation commonly observed in any type of DIC, combined with systemic pathologic hyperfibrinogenolysis caused by underlying disorder that results in severe bleeding due to excessive plasmin formation. Three major pathomechanisms of systemic hyperfibrinogenolysis have been considered: (1) acceleration of tissue-type plasminogen activator (t-PA) release from hypoxic endothelial cells and t-PA-rich storage pools, (2) enhancement of the conversion of plasminogen to plasmin due to specific proteins and receptors that are expressed on cancer cells and endothelial cells, and (3) alternative pathways of fibrinolysis. DIC with fibrinolytic phenotype can be diagnosed by DIC diagnosis followed by the recognition of systemic pathologic hyperfibrin(ogen)olysis. Low fibrinogen levels, high fibrinogen and fibrin degradation products (FDPs), and the FDP/D-dimer ratio are important for the diagnosis of systemic pathologic hyperfibrin(ogen)olysis. Currently, evidence-based treatment strategies for DIC with fibrinolytic phenotypes are lacking. Tranexamic acid appears to be one of the few methods to be effective in the treatment of systemic pathologic hyperfibrin(ogen)olysis. International cooperation for the elucidation of pathomechanisms, establishment of diagnostic criteria, and treatment strategies for DIC with fibrinolytic phenotype are urgent issues in the field of thrombosis and hemostasis.

Altitude-Related Venous Thrombosis With Heart Disease: An Updated Review

Altitude-related venous thrombosis (ARVT) is a condition of growing concern among individuals engaged in high-altitude travel and activities. This updated review explores the epidemiology, pathophysiological mechanisms, clinical presentations, and management of ARVT based on a thematic analysis and synthesis of the existing literature. ARVT's multifactorial etiology involves the interplay of hypobaric hypoxia and endothelial dysfunction, creating a procoagulant state and increasing the risk of thrombosis. Common clinical manifestations include pain, swelling, and redness in the extremities, necessitating accurate and timely diagnosis, particularly in remote settings. Thromboprophylaxis during high-altitude travel and activities plays a crucial role in reducing the risk of ARVT, while anticoagulation remains the mainstay of management. Further research is needed to optimize preventive and treatment strategies, enhancing patient outcomes and safety in high-altitude environments.

Platelet and HIV Interactions and Their Contribution to Non-AIDS Comorbidities

Platelets are anucleate cytoplasmic cell fragments that circulate in the blood, where they are involved in regulating hemostasis. Beyond their normal physiologic role, platelets have emerged as versatile effectors of immune response. During an infection, cell surface receptors enable platelets to recognize viruses, resulting in their activation. Activated platelets release biologically active molecules that further trigger host immune responses to protect the body against infection. Their impact on the immune response is also associated with the recruitment of circulating leukocytes to the site of infection. They can also aggregate with leukocytes, including lymphocytes, monocytes, and neutrophils, to immobilize pathogens and prevent viral dissemination. Despite their host protective role, platelets have also been shown to be associated with various pathophysiological processes. In this review, we will summarize platelet and HIV interactions during infection. We will also highlight and discuss platelet and platelet-derived mediators, how they interact with immune cells, and the multifaceted responsibilities of platelets in HIV infection. Furthermore, we will give an overview of non-AIDS comorbidities linked to platelet dysfunction and the impact of antiretroviral therapy on platelet function.

Complement and coagulation crosstalk - Factor H in the spotlight

The immune complement and the coagulation systems are blood-based proteolytic cascades that are activated by pathway-specific triggers, based on protein-protein interactions and enzymatic cleavage reactions. Activation of these systems is finely balanced and controlled through specific regulatory mechanisms. The complement and coagulation systems are generally viewed as distinct, but have common evolutionary origins, and several interactions between these homologous systems have been reported. This complement and coagulation crosstalk can affect activation, amplification and regulatory functions in both systems. In this review, we summarize the literature on coagulation factors contributing to complement alternative pathway activation and regulation and highlight molecular interactions of the complement alternative pathway regulator factor H with several coagulation factors. We propose a mechanism where factor H interactions with coagulation factors may contribute to both complement and coagulation activation and regulation within the haemostatic system and fibrin clot microenvironment and introduce the emerging role of factor H as a modulator of coagulation. Finally, we discuss the potential impact of these protein interactions in diseases associated with factor H dysregulation or deficiency as well as evidence of coagulation dysfunction.

Acute lower extremity arterial thrombosis associated with nephrotic syndrome in adults: case series and literature review

BACKGROUND

Nephrotic syndrome (NS) is a condition associated with hypercoagulability. Thromboembolic events are a well-recognized complication of NS. Venous thrombosis is well known, while arterial thrombosis, which is more severe, occurs less frequently and is mainly reported in children in the literature. The aim of this study was to understand these rare adult cases of NS associated with acute lower extremity arterial thrombosis and draw attention to them to prevent misdiagnosis and delayed treatment.

METHODS

From January 2011 and October 2022, we conducted a retrospective study of patients with NS and arterial thrombosis. Their clinical manifestations, imaging characteristics, treatments and outcomes were analyzed and compared, and a literature review was performed.

RESULTS

Nine adults with NS and acute lower limb arterial thrombosis were described. In seven of these patients, six had fresh thrombi that preceded the NS diagnosis, while one had a history of NS for 14 years and previously underwent an emergency thrombectomy. Three of the seven patients eventually underwent above-knee amputations, and the other four underwent arterial revascularization with satisfactory recovery of lower-extremity perfusion. In addition to the seven patients mentioned above, the other two received successful anticoagulant treatment, as the thrombosis was present only in the popliteal artery.

CONCLUSION

Acute lower extremity arterial thrombosis is a rare but serious and potentially lethal complication in patients with NS, and early recognition and appropriate management are crucial for good patient outcomes.

Recent Advances in the Management of Microangiopathic Hemolytic Anemias (MAHA): A Narrative Review

Red blood cells (RBCs) start to break down early in hemolytic anemia, which can be chronic or life-threatening. It should be considered while determining if normocytic or macrocytic anemia is present. Hemolysis in the reticuloendothelial system may happen intravascularly, extravascularly, or both. It accounts for a broad spectrum of laboratory and clinical situations, both physiological and pathological. Whenever the frequency of RBC breakdown is rapid enough to lower hemoglobin levels below the normal range, hemolytic anemia occurs. Microangiopathic hemolytic anemia (MAHA) is a term used to describe non-immune hemolysis induced by intravascular RBC fragmentation caused by substances in the tiny blood arteries that generate schistocytes in the peripheral circulation. Microvasculature abnormalities, such as small arterioles and capillaries, are usually involved. Furthermore, MAHA can also be brought on by intravascular devices like a prosthetic heart valve or assistive technologies. Poor deformity results in entrapment, phagocytosis, antibody-mediated elimination through phagocytosis or direct complement activation, fragmentation brought about by microthrombi or acute mechanical stress, oxidation, or spontaneous cellular death. Hemolysis may cause acute anemia, jaundice, hematuria, dyspnea, tiredness, tachycardia, and possibly hypotension. This article aims to synthesize existing research, identify therapeutic strategies, and provide insights into current and emerging approaches for managing this complex hematological disorder.

The Crossroads of the Coagulation System and the Immune System: Interactions and Connections

The coagulation and immune systems, two vital systems in the human body, share intimate connections that fundamentally determine patient health. These systems work together through several common regulatory pathways, including the Tissue Factor (TF) Pathway. Immune cells expressing TF and producing pro-inflammatory cytokines can influence coagulation, while coagulation factors and processes reciprocally impact immune responses by activating immune cells and controlling their functions. These shared pathways contribute to maintaining health and are also involved in various pathological conditions. Dysregulated coagulation, triggered by infection, inflammation, or tissue damage, can result in conditions such as disseminated intravascular coagulation (DIC). Concurrently, immune dysregulation may lead to coagulation disorders and thrombotic complications. This review elucidates these intricate interactions, emphasizing their roles in the pathogenesis of autoimmune diseases and cancer. Understanding the complex interplay between these systems is critical for disease management and the development of effective treatments. By exploring these common regulatory mechanisms, we can uncover innovative therapeutic strategies targeting these intricate disorders. Thus, this paper presents a comprehensive overview of the mutual interaction between the coagulation and immune systems, highlighting its significance in health maintenance and disease pathology.

Case report of Salmonella derby septicemia complicated with co-occurrence of disseminated intravascular coagulation and thrombotic microangiopathy

BACKGROUND

Both disseminated intravascular coagulation and thrombotic microangiopathy are complications of sepsis as Salmonella septicemia, respectively. They are related and have similar clinical characteristics as thrombopenia and organ dysfunctions. They rarely co-occur in some specific cases, which requires a clear distinction.

CASE PRESENTATION

A 22-year-old woman had just undergone intracranial surgery and suffered from Salmonella derby septicemia with multiorgan involvement in the hospital. Laboratory workup demonstrated coagulation disorder, hemolytic anemia, thrombocytopenia, and acute kidney injury, leading to the co-occurrence of disseminated intravascular coagulation and secondary thrombotic microangiopathy. She received antibiotics, plasma exchange therapy, dialysis, mechanical ventilation, fluids, and vasopressors and gained full recovery without complications.

CONCLUSION

Disseminated intravascular coagulation and secondary thrombotic microangiopathy can co-occur in Salmonella derby septicemia. They should be treated cautiously in diagnosis and differential diagnosis. Thrombotic microangiopathy should not be missed just because of the diagnosis of disseminated intravascular coagulation. Proper and timely identification of thrombotic microangiopathy with a diagnostic algorithm is essential for appropriate treatment and better outcomes.

Platelets as a Gauge of Liver Disease Kinetics?

A multitude of laboratory and clinical interferences influence the utility of platelet-based diagnostic indices, including immature platelet fraction, in longitudinal monitoring and prognostication of patients with chronic liver disease (CLD). The complex yet highly regulated molecular basis of platelet production and clearance kinetics becomes dysregulated in liver pathogenesis. These underlying molecular mechanisms, including premature platelet clearance and bone marrow suppression in parallel with the progressive (e.g., treatment-naïve) or regressive (e.g., on-treatment and off-treatment) disease courses, involved in CLDs, may further confound the changes in platelet–liver correlations over time. Platelet count and function are commonly and secondarily altered in vivo in CLDs. However, the precise characterization of platelet functions during cirrhosis, including in vitro platelet aggregation, has proven challenging due to interferences such as thrombocytopenia. A flow cytometric approach may help monitor the unstably rebalanced hyper- and hypoaggregable states in patients with cirrhosis at risk of hyperaggregable, prothrombotic, or bleeding events. Studies have attempted to stratify patients with cirrhosis by substages and prognosis through the use of novel indices such as the ratio of in vitro endogenous platelet aggregation to platelet count. This review attempts to highlight clinical and laboratory precautions in the context of platelet-assisted CLD monitoring.

Serum concentration as a predictor of tigecycline-induced hypofibrinogenemia in critically ill patients: a retrospective cohort study

OBJECTIVES

The objective of this study was to determine the thresholds of serum concentration as a predictor of tigecycline-induced hypofibrinogenemia in critically ill patients.

METHODS

A retrospective cohort study was conducted in ICU patients treated with tigecycline. The clinical data and serum concentration were extracted from the patients' electronic medical records. Patients were divided into hypofibrinogenemia (HF) group and normal group according to fibrinogen (FIB) value. The receiver operating characteristic (ROC) curves and logistic regression was used to derive serum concentration thresholds and quantify the association between exposure thresholds and hypofibrinogenemia while adjusting for confounders.

RESULTS

In total, 100 patients were included. ROC curves analyse showed that tigecycline concentration parameters were strongly predictive of hypofibrinogenemia. Adjusting for duration of tigecycline, C_1/2 ≥ 0.645 mg/L, AUC_0-24 ≥ 20.76 mg∙h/L and C_min ≥ 0.455mg/L were associated with a 3- to 5-fold increased risk of tigecycline-induced hypofibrinogenemia in logistic regression.

CONCLUSION

The findings from this study provide evidence that tigecycline exposure is highly predictive of hypofibrinogenemia, with approximately 3- to 5-fold increased risk. C_1/2 ≥ 0.645 mg/L with best area under ROC curve and NPV appears to be the most appropriate toxicity threshold.