Prognostic impact of platelet distribution width in patients with Crimean-Congo hemorrhagic fever

Vascular dysfunction in hemorrhagic viral fevers: opportunities for organotypic modeling

The hemorrhagic fever viruses (HFVs) cause severe or fatal infections in humans. Named after their common symptom hemorrhage, these viruses induce significant vascular dysfunction by affecting endothelial cells, altering immunity, and disrupting the clotting system. Despite advances in treatments, such as cytokine blocking therapies, disease modifying treatment for this class of pathogen remains elusive. Improved understanding of the pathogenesis of these infections could provide new avenues to treatment. While animal models and traditional 2D cell cultures have contributed insight into the mechanisms by which these pathogens affect the vasculature, these models fall short in replicatingin vivohuman vascular dynamics. The emergence of microphysiological systems (MPSs) offers promising avenues for modeling these complex interactions. These MPS or 'organ-on-chip' models present opportunities to better mimic human vascular responses and thus aid in treatment development. In this review, we explore the impact of HFV on the vasculature by causing endothelial dysfunction, blood clotting irregularities, and immune dysregulation. We highlight how existing MPS have elucidated features of HFV pathogenesis as well as discuss existing knowledge gaps and the challenges in modeling these interactions using MPS. Understanding the intricate mechanisms of vascular dysfunction caused by HFV is crucial in developing therapies not only for these infections, but also for other vasculotropic conditions like sepsis.

New Prognostic Parameter of West Nile Virus: Platelet Distribution Width

Background: West Nile virus (WNV) infection is a viral disease caused by arboviruses. It can cause epidemics of febrile diseases and meningoencephalitis, especially at the end of the summer season. In this study, we aimed to determine the risk factors of WNV encephalitis with a case-control study of the patients followed in our clinic. Materials and Methods: Among the patients who applied to our hospital with sudden onset fever, headache, myalgia, nausea, vomiting, maculopapular rash, viral meningitis, or encephalitis findings in late summer and early autumn, those diagnosed with positive WNV PCR and antibody tests were defined as WNV cases. In the same date range, patients with clinically compatible but negative serological and PCR tests for WNV in our hospital were considered as the control group. Results: WNV infection was diagnosed in 26 of 48 patients who were examined with a preliminary diagnosis of WNV infection, and the other 22 patients were considered as the control group. A statistically significant difference was found between the two groups in C-reactive protein, procalcitonin, 1-h erythrocyte sedimentation rate, alkaline phosphatase, platelet, and platelet distribution width (PDW). PDW >17.85% indicated WNV infection with 82% sensitivity and 91% specificity. PDW percentage >17.85 increased the risk of WNV infection by 6.1 times. The power of the study was calculated as 83%. Conclusion: The most common findings in WNV cases were fever and confusion. WNV infection should be considered in the differential diagnosis in patients with fever and confusion in September and October in settlements on the migration route of birds. The percentage of PDW in whole blood examination can guide the differential diagnosis of WNV cases.

Low-molecular-weight heparin therapy reduces 28-day mortality in patients with sepsis-3 by improving inflammation and coagulopathy

Background and aim

Sepsis is a syndromic response to infection and is associated with high mortality, thus imposing a significant global burden of disease. Although low-molecular-weight heparin (LMWH) has been recommended to prevent venous thromboembolism, its anticoagulant and anti-inflammatory effects in sepsis remain controversial. Owing to the modification of the Sepsis-3 definition and diagnostic criteria, further evaluation of the efficacy and benefit population of LMWH is required.

Methods

We performed a retrospective cohort study to assess whether LMWH improved the inflammation, coagulopathy, and clinical outcomes against Sepsis-3 and to identify the target patients. All patients diagnosed with sepsis at the First Affiliated Hospital of Xi'an Jiaotong University (the largest general hospital in northwest China) from January 2016 to December 2020 were recruited and re-evaluated using Sepsis-3 criteria.

Results

After 1:1 propensity score matching, 88 pairs of patients were categorized into the treatment and control groups based on subcutaneous LMWH administration. Compared with the control group, a significantly lower 28-day mortality was observed in the LMWH group (26.1 vs. 42.0%, p = 0.026) with a comparable incidence of major bleeding events (6.8 vs. 8.0%, p = 0.773). Cox regression analysis showed that LMWH administration was the independent protective factor for septic patients (aHR, 0.48; 95% CI, 0.29-0.81; p = 0.006). Correspondingly, the LMWH treatment group showed a significant improvement in inflammation and coagulopathy. Further subgroup analysis showed that LMWH therapy was associated with favorable outcomes in patients younger than 60 years and diagnosed with sepsis-induced coagulopathy (SIC), ISTH overt DIC, non-septic shock, or non-diabetics and in patients included in the moderate-risk group (APACHE II score 20-35 or SOFA score 8-12).

Conclusion

Our study results showed that LMWH improves 28-day mortality by improving inflammatory response and coagulopathy in patients meeting Sepsis-3 criteria. The SIC and ISTH overt DIC scoring systems can better identify septic patients who are likely to benefit more from LMWH administration.

Thrombocytopenia in Virus Infections

Thrombocytopenia, which signifies a low platelet count usually below 150 × 10⁹/L, is a common finding following or during many viral infections. In clinical medicine, mild thrombocytopenia, combined with lymphopenia in a patient with signs and symptoms of an infectious disease, raises the suspicion of a viral infection. This phenomenon is classically attributed to platelet consumption due to inflammation-induced coagulation, sequestration from the circulation by phagocytosis and hypersplenism, and impaired platelet production due to defective megakaryopoiesis or cytokine-induced myelosuppression. All these mechanisms, while plausible and supported by substantial evidence, regard platelets as passive bystanders during viral infection. However, platelets are increasingly recognized as active players in the (antiviral) immune response and have been shown to interact with cells of the innate and adaptive immune system as well as directly with viruses. These findings can be of interest both for understanding the pathogenesis of viral infectious diseases and predicting outcome. In this review, we will summarize and discuss the literature currently available on various mechanisms within the relationship between thrombocytopenia and virus infections.

Platelet Distribution Width at First Day of Hospital Admission in Patients with Hemorrhagic Fever with Renal Syndrome Caused by Hantaan Virus May Predict Disease Severity and Critical Patients' Survival

Thrombocytopenia is one of the main characteristics of hemorrhagic fever with renal syndrome (HFRS). This study aimed to evaluate the associations of platelet distribution width (PDW) with the disease severity and critical patients' survival of HFRS. The demographics, clinical data, and white blood cell and platelet parameters including PDW in 260 patients hospitalized for HFRS were analyzed. The results showed that PDW on the first day (PDW1) was positively associated with the disease severity (p = 0.005). Multiple regression analysis showed that in addition to age (odds ratio [OR], 1.091; 95% confidence interval [CI], 1.015-1.172) and occurrence of sepsis (OR, 22.283; 95% CI, 2.985-166.325), PDW1 (OR, 0.782; 95% CI, 0.617-0.992) was a risk factor of the mortality, having an area under the receiver operating characteristic curve of 0.709 (95% CI, 0.572-0.846, p = 0.013) for predicting mortality, with a sensitivity of 70% and a specificity of 67% at a cutoff of 16.5 fL, in patients with critical HFRS. These results suggest the potential of PDW at the first day of hospitalization as a valuable parameter for evaluating the severity of HFRS and a moderate parameter for predicting the prognosis of critical HFRS patients. A prospective study in large patient population is needed to validate these findings.