Thrombocytopenia in Virus Infections

Yohimbine Treatment Alleviates Cardiac Inflammation/Injury and Improves Cardiac Hemodynamics by Modulating Pro-Inflammatory and Oxidative Stress Indicators

Acute myocarditis, also known as myocardial inflammation, is a self-limited condition caused by systemic infection with cardiotropic pathogens, primarily viruses, bacteria, or fungi. Despite significant research, inflammatory cardiomyopathy exacerbated by heart failure, arrhythmia, or left ventricular dysfunction and it has a dismal prognosis. In this study, we aimed to evaluate the therapeutic effect of yohimbine against lipopolysaccharide (LPS) induced myocarditis in rat model. The anti-inflammatory activity of yohimbine was assessed in in-vitro using RAW 264.7 and H9C2 cells. Myocarditis was induced in rats by injecting LPS (10 mg/kg), following the rats were treated with dexamethasone (2 mg/kg) or yohimbine (2.5, 5, and 10 mg/kg) for 12 h and their therapeutic activity was examined using various techniques. Yohimbine treatment significantly attenuated the LPS-mediated inflammatory markers expression in the in-vitro model. In-vivo studies proved that yohimbine treatment significantly reduced the LPS-induced increase of cardiac-specific markers, inflammatory cell counts, and pro-inflammatory markers expression compared to LPS-control samples. LPS administration considerably affected the ECG, RR, PR, QRS, QT, ST intervals, and hemodynamic parameters, and caused abnormal pathological parameters, in contrast, yohimbine treatment substantially improved the cardiac parameters, mitigated the apoptosis in myocardial cells and ameliorated the histopathological abnormalities that resulted in an improved survival rate. LPS-induced elevation of cardiac troponin-I, myeloperoxidase, CD-68, and neutrophil elastase levels were significantly attenuated upon yohimbine treatment. Further investigation showed that yohimbine exerts an anti-inflammatory effect partly by modulating the MAPK pathway. This study emphasizes yohimbine's therapeutic benefit against LPS-induced myocarditis and associated inflammatory markers response by regulating the MAPK pathway.

An Investigation of Mortality Associated With Comorbid Pneumonia and Thrombocytopenia in a Rural Southwest Missouri Hospital System

BACKGROUND

Pneumonia places a significant burden on individuals and society, contributing to a substantial number of hospital admissions, emergency department visits, deaths, and healthcare costs each year. Comorbidities can greatly increase the risk of poor outcomes when associated with pneumonia. One comorbidity that has yet to be thoroughly researched is thrombocytopenia, which is known to play an important role in activating the immune response to infections. A decrease in platelet count may limit the immune response and consequently increase mortality in patients with pneumonia. The purpose of this study was to investigate whether comorbid thrombocytopenia and pneumonia are associated with poor outcomes.

METHODS

This study was a retrospective cohort analysis comparing mortality rates among patients with comorbid thrombocytopenia and pneumonia, pneumonia without thrombocytopenia, and thrombocytopenia without pneumonia. Data were collected from Freeman Health System using International Classification of Diseases, Tenth Revision (ICD-10) codes from January 1, 2019, to December 31, 2021. ICD-10 codes for pneumonia and thrombocytopenia were extracted and stratified into three groups: those with both pneumonia and thrombocytopenia, those with pneumonia without thrombocytopenia, and those with thrombocytopenia without pneumonia. Mortality rates were then compared across the three groups.

RESULTS

There were 4,414 patients admitted with pneumonia and 1,157 admissions for thrombocytopenia without pneumonia. Among the 4,414 patients admitted with pneumonia, 3,902 did not have thrombocytopenia, while 512 had thrombocytopenia. Of the patients without thrombocytopenia, 14% (3,902) expired. Among the 512 patients with thrombocytopenia, 43% expired. In the thrombocytopenia without pneumonia group, 11% (1,157) expired.

CONCLUSION

These results indicate a significant increase in mortality in patients with both pneumonia and thrombocytopenia compared to those with pneumonia without thrombocytopenia (an increase in mortality of 28.93% with a 95% CI: 24.50-33.36%, P < 0.0001). While pneumonia itself increases mortality compared to the general population, patients with both pneumonia and thrombocytopenia exhibit even higher mortality rates.

Hemostasis Testing in the Emergency Department: A Narrative Review

Routine laboratory screening is typically performed at initial evaluation of the vast majority of presentations to the emergency department (ED). These laboratory results are crucial to the diagnostic process, as they may influence up to 70% of clinical decisions. However, despite the usefulness of biological assessments, many tests performed are inappropriate or of doubtful clinical relevance. This overutilization rate of laboratory testing in hospitals, which represents a significant medical-economic burden, ranges from 20 to 67%, with coagulation tests at the top of the list. While reviews frequently focus on nonintensive care units, there are few published assessments of emergency-specific interventions or guidelines/guidance to date. The aim of this review is to highlight current recommendations for hemostasis evaluation in the emergency setting with a specific analysis of common situations leading to ED admissions, such as suspected venous thrombosis or severe bleeding. We revisit the evidence related to the assessment of patient's hemostatic capacity based on comprehensive history taking and physical examination as well as best practice recommendations for blood sample collection to ensure the reliability of results. This review also includes an examination of various currently available point of care tests and a comprehensive discussion on indications, limitations, and interpretation of these tests.

Innate immune response of snakehead fish to Indian strain of snakehead rhabdovirus (SHRV-In) infection and the infectivity potential of the virus to other freshwater fishes

A new virus known as snakehead rhabdovirus (SHRV-In) was discovered in South India in striped snakehead (Channa striata) that had hemorrhagic patches and cutaneous ulcerations. The virus is the most potentially harmful pathogen of snakehead because it could cause 100% mortality within 5 days. The goal of the current investigation was to evaluate the infectivity of rhabdovirus in freshwater fishes and to analyze the immune response in snakehead fish after challenge with SHRV-In. The infectivity study of SHRV-In against three freshwater fish such as tilapia, grass carp and loach showed that the virus could not induce mortality in any of them. Snakehead fish challenged with SHRV-In showed significant (p < 0.05) changes in haematological parameters such as red blood cell (RBC), haemoglobin (HGB), haematocrit (HCT), mean corpuscular haemoglobin concentration (MCHC), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), white blood cell (WBC), total platelet (PLT) counts, mean platelet volume (MPV) and immunological markers such as respiratory burst, superoxide dismutase, catalase activity and myeloperoxidase activity at 6, 12, 24 and 48 hpi. Real time PCR was executed to examine the expression profile of innate immune genes such as IRF-7, IL-8 and IL-12 in Snakehead fish at 6, 12, 24 and 48 h post SHRV-In infection. Immune gene expression of IRF-7, IL-8 and IL-12 were up-regulated in the spleen when compared to kidney at 6 and 12 hpi. However, the expression level of all the genes was down-regulated at 24 and 48 hpi. The down regulation of innate immune genes after 24 hpi in these tissues may be the result of increased multiplication of SHRV-In by interfering with the immune signaling pathway.

Differentiating viral and bacterial infections: A machine learning model based on routine blood test values

The growing threat of antibiotic resistance necessitates accurate differentiation between bacterial and viral infections for proper antibiotic administration. In this study, a Virus vs. Bacteria machine learning model was developed to distinguish between these infection types using 16 routine blood test results, C-reactive protein concentration (CRP), biological sex, and age. With a dataset of 44,120 cases from a single medical center, the model achieved an accuracy of 82.2 %, a sensitivity of 79.7 %, a specificity of 84.5 %, a Brier score of 0.129, and an area under the ROC curve (AUC) of 0.905, outperforming a CRP-based decision rule. Notably, the machine learning model enhanced accuracy within the CRP range of 10-40 mg/L, a range where CRP alone is less informative. These results highlight the advantage of integrating multiple blood parameters in diagnostics. The "Virus vs. Bacteria" model paves the way for advanced diagnostic tools, leveraging machine learning to optimize infection management.

Multi-omics analysis reveals COVID-19 vaccine induced attenuation of inflammatory responses during breakthrough disease

The immune mechanisms mediating COVID-19 vaccine attenuation of COVID-19 remain undescribed. We conducted comprehensive analyses detailing immune responses to SARS-CoV-2 virus in blood post-vaccination with ChAdOx1 nCoV-19 or a placebo. Samples from randomised placebo-controlled trials (NCT04324606 and NCT04400838) were taken at baseline, onset of COVID-19-like symptoms, and 7 days later, confirming COVID-19 using nucleic amplification test (NAAT test) via real-time PCR (RT-PCR). Serum cytokines were measured with multiplexed immunoassays. The transcriptome was analysed with long, short and small RNA sequencing. We found attenuation of RNA inflammatory signatures in ChAdOx1 nCoV-19 compared with placebo vaccinees and reduced levels of serum proteins associated with COVID-19 severity. KREMEN1, a putative alternative SARS-CoV-2 receptor, was downregulated in placebo compared with ChAdOx1 nCoV-19 vaccinees. Vaccination ameliorates reductions in cell counts across leukocyte populations and platelets noted at COVID-19 onset, without inducing potentially deleterious Th2-skewed immune responses. Multi-omics integration links a global reduction in miRNA expression at COVID-19 onset to increased pro-inflammatory responses at the mRNA level. This study reveals insights into the role of COVID-19 vaccines in mitigating disease severity by abrogating pro-inflammatory responses associated with severe COVID-19, affirming vaccine-mediated benefit in breakthrough infection, and highlighting the importance of clinically relevant endpoints in vaccine evaluation.

Viruses and thrombocytopenia

Thrombocytopenia, characterized by a decrease in platelet count, is a multifaceted clinical manifestation that can arise from various underlying causes. This review delves into the intriguing nexus between viruses and thrombocytopenia, shedding light on intricate pathophysiological mechanisms and highlighting the pivotal role of platelets in viral infections. The review further navigates the landscape of thrombocytopenia in relation to specific viruses, and sheds light on the diverse mechanisms through which hepatitis C virus (HCV), measles virus, parvovirus B19, and other viral agents contribute to platelet depletion. As we gain deeper insights into these interactions, we move closer to elucidating potential therapeutic avenues and preventive strategies for managing thrombocytopenia in the context of viral infections.

Valproic Acid-Induced Thrombocytopenia in Treatment-Resistant GABRB3 Genetic Epilepsy: A Case Report

Valproic acid (VPA) is utilized in the management of a variety of seizure and mood disorders. A rare side effect of this medication is dose-dependent thrombocytopenia. In this case, we report a patient with a treatment-resistant epilepsy GABRB3 genetic variant phenotype who was admitted for sepsis and found to have significant thrombocytopenia with clinical manifestations of epistaxis and easy bruising, which was found to be due to VPA use rather than secondary to other clinical pathologies. The patient's clinical condition improved with supportive treatment including fluid rehydration. Platelet counts normalized after a transfusion and holding of her valproate. She experienced breakthrough seizures despite the initiation of diazepam. The decision was made to restart VPA per Neurology consult recommendations for better seizure control. She had no breakthrough seizures reported after restarting VPA in the hospital. This case highlights the importance of monitoring antiseizure medication side effects, especially in populations at higher risk due to treatment resistance.

The blood routine test holds screening values for influenza A in 2023: a retrospective study

Background

Influenza A is the most common viral pathogen isolated from pediatric clinics during influenza seasons. Some young patients with influenza manifest rapid progression with high fever and severe sequelae, such as pneumonia and meningitis. Therefore, early diagnosis and prompt treatment are highly important. Specific diagnostic tests currently include antigen detection, antibody detection, nucleic acid test and virus isolation. Rapid antigen testing is the most commonly adopted method in the outpatient setting, but false negative results are frequently observed, which causes delayed treatment and severe outcome. Routine blood test is the most commonly used detection for the outpatients. Incorporating specific blood cell counts into rapid antigen test may overcome some technical issues and enable accurate early diagnosis.

Methods

We enrolled 537 children with influenza-like symptoms like fever or respiratory symptoms from pediatric outpatients and 110 children without infectious diseases for control. Routine blood tests detected by a routine analyzer and influenza A virus antigen detection were performed in the patients. Significant blood routine parameters between groups were examined by statistical tests. Parameters in routine blood test were assessed by the receiver operating characteristic curve to find the screening indicators of influenza A. Multivariate logistic regression were used to establish the optimal combinations of blood routine parameters in our screening model.

Results

Two subgroups were set according to age: ≤6 years old group and >6 years old group. In each group, patients were further divided into three subgroups: the influenza A-positive-result group (A+ group) (n=259), influenza A-negative-result group (A- group) (n=277) and healthy control group (H group) (n=110). Most routine blood parameters showed significant differences among the three subgroups in each age group. Notably, lymphocyte (LYM) number, platelet (PLT) number, lymphocyte-to-monocyte ratio (LMR) and LYM multiplied by PLT (LYM*PLT) exhibited extremely significant differences. Using A- group as a reference based on the area under the curve (AUC), both age groups had a similar trend. For A- group, the optimal cutoff value of LYM*PLT was 221.6, the AUC, the sensitivity and specificity were 0.6830, 55.71% and 76.92% in the ≤6 years old group. Meanwhile, the cutoff value of LYM*PLT was 196.7, and the AUC, the sensitivity and specificity were 0.6448, 53.97% and 70.81%, respectively in the >6 years old group. Screening model based on multivariate logistic regression model revealed that LYM*PLT was the optimal parameter combinations in ≤6 years old group (AUC =0.7202), while LYM and PLT were the optimal parameter combinations in >6 years old group (AUC =0.6760).

Conclusions

Several blood routine parameters in children with influenza A demonstrate differential levels in both age subgroups. The LYM*PLT exhibits the potential screening value of influenza infection.

Levels of peripheral blood routine, biochemical and coagulation parameters in patients with hemorrhagic fever with renal syndrome and their relationship with prognosis: an observational cohort study

BACKGROUND

Hantaan virus (HTNV), Seoul virus (SEOV) and Puumala virus (PUUV) are major serotypes of the Hantavirus, which can cause hemorrhagic fever with renal syndrome (HFRS). The pathophysiology of HFRS in humans is complex and the determinants associated with mortality, especially the coagulation and fibrinolysis disorders, are still not been fully elucidated. Severe patients usually manifest multiple complications except for acute kidney injury (AKI). The aim of this study was to observe the levels of peripheral blood routine, biochemical and coagulation parameters during the early stage, so as to find independent risk factors closely related to the prognosis, which may provide theoretical basis for targeted treatment and evaluation.

METHODS

A total of 395 HFRS patients from December 2015 to December 2018 were retrospectively enrolled. According to prognosis, they were divided into a survival group (n = 368) and a death group (n = 27). The peripheral blood routine, biochemical and coagulation parameters were compared between the two groups on admission. The relationship between the parameters mentioned above and prognosis was analyzed, and the dynamic changes of the coagulation and fibrinolysis parameters during the first week after admission were further observed.

RESULTS

In addition to AKI, liver injury was also common among the enrolled patients. Patients in the death group manifested higher levels of white blood cell counts (WBC) on admission. 27.30% (107/392) of the patients enrolled presented with disseminated intravascular coagulation (DIC) on admission and DIC is more common in the death group; The death patients manifested longer prothrombin time (PT) and activated partial thromboplastin time (APTT), higher D-dimer and fibrinogen degradation product (FDP), and lower levels of platelets (PLT) and fibrinogen (Fib) compared with those of the survival patients. The proportion of D-dimer and FDP abnormalities are higher than PT, APTT and Fib. Prolonged PT, low level of Fib and elevated total bilirubin (TBIL) on admission were considered as independent risk factors for prognosis (death).

CONCLUSIONS

Detection of PT, Fib and TBIL on admission is necessary, which might be benefit to early predicting prognosis. It is also important to pay attention to the dynamic coagulation disorders and hyperfibrinolysis during the early stage in the severe HFRS patients.

Persistent, Poorly Responsive Immune Thrombocytopenia Secondary to Asymptomatic COVID-19 Infection in a Child

Immune thrombocytopenic purpura (ITP) secondary to asymptomatic COVID-19 infection, especially in children, is not reported. Furthermore, persistent, treatment-resistant ITP secondary to COVID-19 is not reported. We report a previously healthy 14-year-old Asian boy who developed secondary ITP following an asymptomatic COVID-19 infection and is having a relapsing and remitting cause with poor response to immunosuppressants even after 21 months following the diagnosis. This case emphasizes the importance of testing for COVID-19 in newly diagnosed ITP patients and the need for follow-up platelet counts in patients who recover from COVID-19 as it may follow into developing secondary ITP yet being asymptomatic until you present with a bleeding complication of ITP. The poor response to standard immunosuppression warrants more understanding of the pathophysiology of persistently low platelets following COVID-19 infection. Long-term sequelae of the disease highlight the importance of getting vaccinated for COVID-19 despite COVID-19 being no longer a global emergency.

It's in the blood: a review of the hematological system in SARS-CoV-2-associated COVID-19

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to an unprecedented global healthcare crisis. While SARS-CoV-2-associated COVID-19 affects primarily the respiratory system, patients with COVID-19 frequently develop extrapulmonary manifestations. Notably, changes in the hematological system, including lymphocytopenia, neutrophilia and significant abnormalities of hemostatic markers, were observed early in the pandemic. Hematological manifestations have since been recognized as important parameters in the pathophysiology of SARS-CoV-2 and in the management of patients with COVID-19. In this narrative review, we summarize the state-of-the-art regarding the hematological and hemostatic abnormalities observed in patients with SARS-CoV-2-associated COVID-19, as well as the current understanding of the hematological system in the pathophysiology of acute and chronic SARS-CoV-2-associated COVID-19.

Non-Invasive Prediction Scores for Hepatitis B Virus- and Hepatitis D Virus-Infected Patients-A Cohort from the North-Eastern Part of Romania

Approximately 62-72 million people are infected worldwide with HDV. Patients with chronic hepatitis D (CHD) have a higher risk of developing cirrhosis or hepatocellular carcinoma (HCC) and an increased mortality rate compared to those with chronic hepatitis B (CHB). The stage of liver fibrosis or the risk of developing HCC can also be estimated by non-invasive scores, which are cost effective, easier to apply, and reproducible. In this study, we aimed to evaluate the predictive value of four non-invasive scores (FIB-4, APRI, AST/ALT ratio, and aMAP) in assessing severe fibrosis/cirrhosis and the presence of HCC in patients with HBV/HDV superinfection, as compared with HBV mono-infection. Our 8-year retrospective analysis revealed that HDV-infected patients had a 2-3 times higher risk of developing cirrhosis and HCC than HBV-mono-infected subjects. High AST and ALT baseline levels qualified as independent predictors for cirrhosis development in both groups. The following fibrosis scores, FIB-4, APRI score, and AAR, were significantly increased when cirrhosis was present at baseline and showed a good prediction for developing cirrhosis in the CHD group. The aMAP score, a risk predictor for HCC, showed significantly higher values in patients with HCC in both groups. Nonetheless, non-invasive scores should always be considered for monitoring patients with CHB and CHD, but only when associated with other diagnosis methods.

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.

Severe fever with thrombocytopenia syndrome virus induces platelet activation and apoptosis via a reactive oxygen species-dependent pathway

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tick-borne infectious disease caused by the SFTS virus (SFTSV) and with a high fatality rate. Thrombocytopenia is a major clinical manifestation observed in SFTS patients, but the underlying mechanism remains largely unclear. Here, we explored the effects of SFTSV infection on platelet function in vivo in severely infected SFTSV IFNar-/- mice and on mouse and human platelet function in vitro. Results showed that SFTSV-induced platelet clearance acceleration may be the main reason for thrombocytopenia. SFTSV-potentiated platelet activation and apoptosis were also observed in infected mice. Further investigation showed that SFTSV infection induced platelet reactive oxygen species (ROS) production and mitochondrial dysfunction. In vitro experiments revealed that administration of SFTSV or SFTSV glycoprotein (Gn) increased activation, apoptosis, ROS production, and mitochondrial dysfunction in separated mouse platelets, which could be effectively ameliorated by the application of antioxidants (NAC (N-acetyl-l-cysteine), SKQ1 (10-(6'-plastoquinonyl) decyltriphenylphosphonium) and resveratrol). In vivo experiments showed that the antioxidants partially rescued SFTSV infection-induced thrombocytopenia by improving excessive ROS production and mitochondrial dysfunction and down-regulating platelet apoptosis and activation. Furthermore, while SFTSV and Gn directly potentiated human platelet activation, it was completely abolished by antioxidants. This study revealed that SFTSV and Gn can directly trigger platelet activation and apoptosis in an ROS-MAPK-dependent manner, which may contribute to thrombocytopenia and hemorrhage during infection, but can be abolished by antioxidants.

Management of patients on antithrombotic therapy with severe infections: a joint clinical consensus statement of the ESC Working Group on Thrombosis, the ESC Working Group on Atherosclerosis and Vascular Biology, and the International Society on Thrombosis and Haemostasis

Patients with severe infections and a pre-existing indication for antithrombotic therapy, i.e. antiplatelet agents, anticoagulant drugs, or their combinations, require integrated clinical counselling among coagulation, infectious disease, and cardiology specialists, due to sepsis-induced coagulopathy that frequently occurs. Bacterial and viral pathogens constitute an increasing threat to global public health, especially for patients with ongoing antithrombotic treatment who have a high risk of thrombotic recurrences and high susceptibility to severe infections with increased morbidity and mortality. Similarly, sepsis survivors are at increased risk for major vascular events. Coagulopathy, which often complicates severe infections, is associated with a high mortality and obligates clinicians to adjust antithrombotic drug type and dosing to avoid bleeding while preventing thrombotic complications. This clinical consensus statement reviews the best available evidence to provide expert opinion and statements on the management of patients hospitalized for severe bacterial or viral infections with a pre-existing indication for antithrombotic therapy (single or combined), in whom sepsis-induced coagulopathy is often observed. Balancing the risk of thrombosis and bleeding in these patients and preventing infections with vaccines, if available, are crucial to prevent events or improve outcomes and prognosis.

Children with Chronic Immune Thrombocytopenia Exhibit High Expression of Human Endogenous Retroviruses TRIM28 and SETDB1

Chronic immune thrombocytopenia (CITP) is an autoimmune disease whose underlying biologic mechanisms remain elusive. Human endogenous retroviruses (HERVs) derive from ancestral infections and constitute about 8% of our genome. A wealth of clinical and experimental studies highlights their pivotal pathogenetic role in autoimmune diseases. Epigenetic mechanisms, such as those modulated by TRIM28 and SETDB1, are involved in HERV activation and regulation of immune response. We assessed, through a polymerase chain reaction real-time Taqman amplification assay, the transcription levels of pol genes of HERV-H, HERV-K, and HERV-W; env genes of Syncytin (SYN)1, SYN2, and HERV-W; as well as TRIM28 and SETDB1 in whole blood from 34 children with CITP and age-matched healthy controls (HC). The transcriptional levels of all HERV sequences, with the exception of HERV-W-env, were significantly enhanced in children with CITP as compared to HC. Patients on eltrombopag treatment exhibited lower expression of SYN1, SYN2, and HERV-W-env as compared to untreated patients. The mRNA concentrations of TRIM28 and SETDB1 were significantly higher and were positively correlated with those of HERVs in CITP patients. The over-expressions of HERVs and TRIM28/SETDB1 and their positive correlations in patients with CITP are suggestive clues of their contribution to the pathogenesis of the disease and support innovative interventions to inhibit HERV and TRIM28/SETDB1 expressions in patients unresponsive to standard therapies.

Prognostic Value of Routine Biomarkers in the Early Stage of COVID-19

Various biomarkers like certain complete blood cell count parameters and the derived ratios including neutrophil-lymphocyte ratio are commonly used to evaluate disease severity. Our study aimed to establish if baseline levels of complete blood cell count-derived biomarkers and CRP, measured before any treatment which can interfere with their values, could serve as a predictor of development of pneumonia and the need for hospitalization requiring oxygen therapy. We retrospectively analyzed the laboratory data of 200 consecutive patients without comorbidities, who denied usage of medications prior to blood analysis and visited a COVID-19 ambulance between October and December 2021. Multivariate regression analysis extracted older age, elevated CRP and lower eosinophil count as significant independent predictors of pneumonia (p = 0.003, p = 0.000, p = 0.046, respectively). Independent predictors of hospitalization were higher CRP (p = 0.000) and lower platelet count (p = 0.005). There was no significant difference in the neutrophil-lymphocyte and platelet-lymphocyte ratios between examined groups. Individual biomarkers such as platelet and eosinophil count might be better in predicting the severity of COVID-19 than the neutrophil-lymphocyte and platelet-lymphocyte ratios.

Platelet role in the prediction of MIS-C severity

Introduction

Multisystem inflammatory syndrome in children (MIS-C) has been reported as one of the cytokine storm syndromes associated with COVID-19. Despite the several proposed diagnostic criteria, MIS-C remains a diagnostic and clinical challenge. Recent studies have demonstrated that platelets (PLTs) play a crucial role in COVID-19 infection and its prognosis. This study aimed to investigate the clinical importance of PLT count and PLT indices in predicting MIS-C severity in children.

Patients and methods

We conducted a retrospective single-center study at our university hospital. A total of 43 patients diagnosed with MIS-C during a 2-year period (from October 2020 to October 2022) were included in the study. MIS-C severity was evaluated according to the composite severity score.

Results

Half of the patients were treated in the pediatric intensive care unit. No single clinical sign was associated with a severe condition, except for shock (p = 0.041). All the routine biomarkers, such as complete blood count (CBC) and C-reactive protein (CRP), used for MIS-C diagnosis were significant in predicting MIS-C severity. Single PLT parameters, such as mean PLT volume, plateletcrit, or PLT distribution width, did not differ between the severity groups. However, we found that a combination of PLT count and the previously mentioned PLT indices had the potential to predict MIS-C severity.

Conclusions

Our study emphasizes the importance of PLT in MIS-C pathogenesis and severity. It revealed that together with routine biomarkers (e.g., CBC and CRP), it could highly improve the prediction of MIS-C severity.

Sepsis - it is all about the platelets

Sepsis is accompanied by thrombocytopenia and the severity of the thrombocytopenia is associated with mortality. This thrombocytopenia is characteristic of disseminated intravascular coagulation (DIC), the sepsis-associated coagulopathy. Many of the pathogens, both bacterial and viral, that cause sepsis also directly activate platelets, which suggests that pathogen-induced platelet activation leads to systemic thrombosis and drives the multi-organ failure of DIC. In this paper we review the mechanisms of platelet activation by pathogens and the evidence for a role for anti-platelet agents in the management of sepsis.

Regulation of megakaryo/thrombopoiesis by endosomal toll-like receptor 7 and 8 activation of CD34+ cells in a viral infection model

Background

CD34+ cells, megakaryocytes (MKs), and platelets express toll-like receptors (TLRs) that enable these cells to amplify the host innate immune response. However, the role of TLR7/TLR8 activation in megakaryopoiesis has not yet been investigated.

Objectives

We evaluated the effect of coxsackievirus B3 (CVB3) and synthetic TLR7/TLR8 agonists on the development of human MKs and production of platelets.

Methods

CD34+ cells from human umbilical cord were inoculated with CVB3 or stimulated with synthetic TLR7/TLR8 agonists and then cultured in the presence of thrombopoietin.

Results

CD34+ cells, MK progenitor cells, and mature MKs expressed TLR7 and TLR8, and exposure to CVB3 resulted in productive infection, as determined by the presence of viral infectious particles in culture supernatants. Cell expansion, differentiation into MKs, MK maturation, and platelet biogenesis were significantly reduced in CD34+-infected cultures. The reduction in MK growth was not due to an alteration in cellular proliferation but was accompanied by an increase in cellular apoptosis and pyroptosis. Impairment of MK generation and maturation of viable cells were also associated with decreased expression of transcription factors involved in these processes. These effects were completely abrogated by TLR7 but not TLR8 antagonists and mimicked by TLR7 but not TLR8 agonists. CVB3 infection of CD34+ cells increased the immunophenotype of MKs characterized as CD148+/CD48+ or CD41+/CD53+ cells.

Conclusion

These data suggest a novel role of TLR7 in megakaryo/thrombopoiesis that may contribute to a better understanding of the molecular basis underlying thrombocytopenia and the immunologic role of MKs in viral infection processes.

Blood Platelets in Infection: The Multiple Roles of the Platelet Signalling Machinery

Platelets are classically recognized for their important role in hemostasis and thrombosis but they are also involved in many other physiological and pathophysiological processes, including infection. Platelets are among the first cells recruited to sites of inflammation and infection and they exert their antimicrobial response actively cooperating with the immune system. This review aims to summarize the current knowledge on platelet receptor interaction with different types of pathogens and the consequent modulations of innate and adaptive immune responses.

A Case of COVID-19-Induced Immune Thrombocytopenia (ITP) in an Adult Female: An Under-Recognized Emerging Phenomenon

Coronavirus disease 2019 (COVID-19) follows a mild course in majority of cases, but some patients may develop non-pulmonary yet life-threatening complications. A Pandora's box had been opened when multisystem hyper-inflammatory syndromes and autoimmune diseases that had been described previously in children and young adults, that are associated with COVID-19, have now emerged in adults. They need to be recognized as important sequelae of severe COVID-19 disease. Immune thrombocytopenia (ITP) or thrombocytopenic purpura is an autoantibody and T-cell-mediated autoimmune disorder characterized by isolated thrombocytopenia, which can be triggered by different infections. First-line treatment of severe ITP includes platelet transfusions in life-threatening cases, followed by corticosteroids and intravenous immunoglobulins (IVIG). Since the beginning of the pandemic, more and more cases of COVID-19-associated ITP have been reported. We report a case of acquired ITP in a young woman that could only be attributed to her COVID-19 infection and was refractory to platelet transfusion, requiring further treatments. The aim of this report is to review some of the etiologies and purposed molecular mechanisms of the autoimmune nature of the disease and to focus on diagnosis and treatment. We will review the current literature surrounding this non-pulmonary manifestation of COVID-19 and current treatment options for this uncommon presentation of ITP.

Scoping Review on Epigenetic Mechanisms in Primary Immune Thrombocytopenia

Immune Thrombocytopenia (ITP) is an autoimmune blood disorder that involves multiple pathways responsible for the homeostasis of the immune system. Numerous pieces of literature have proposed the potential of immune-related genes as diagnostic and prognostic biomarkers, which mostly implicate the role of B cells and T cells in the pathogenesis of ITP. However, a more in-depth understanding is required of how these immune-related genes are regulated. Thus, this scoping review aims to collate evidence and further elucidate each possible epigenetics mechanism in the regulation of immunological pathways pertinent to the pathogenesis of ITP. This encompasses DNA methylation, histone modification, and non-coding RNA. A total of 41 studies were scrutinized to further clarify how each of the epigenetics mechanisms is related to the pathogenesis of ITP. Identifying epigenetics mechanisms will provide a new paradigm that may assist in the diagnosis and treatment of immune thrombocytopenia.

Influence of confirmed viral infection on adult acute fulminant myocarditis supported with extracorporeal membrane oxygenation

BACKGROUND

The impact of etiologies of acute fulminant myocarditis (AFM), which requires extracorporeal membrane oxygenation (ECMO), on clinical outcomes remains unknown. This study aimed to investigate the risk factors for ECMO weaning and mortality among patients with AFM due to viral etiologies in a tertiary referral medical center.

METHODS

We included 33 adults with AFM who received ECMO and were admitted between January 2002 and January 2021. General demographics, laboratory data, echocardiography findings, and long-term outcomes were analyzed for confirmed viral etiology and unconfirmed etiology groups.

RESULTS

The overall hospital survival rate was 54.5%. The age, sex, severity of the hemodynamic condition, and cardiac rhythm were similar between the two groups. Multivariate Cox regression analysis revealed that a confirmed viral etiology (HR 4.201, 95% CI 1.061-16.666), peri-ECMO renal replacement therapy (RRT) (HR 9.804, 1.140-83.333) and a high positive end-expiratory pressure (PEEP) in the ventilator settings at 24 h after ECMO (HR 1.479, 1.020-2.143) were significant prognostic factors for in-hospital mortality. Peri-ECMO RRT was also a significant negative prognostic factor for successful ECMO weaning (OR 0.061, 0.006-0.600) in the multivariate logistic model.

CONCLUSIONS

Among AFM patients receiving ECMO support, RRT use was associated with a decreased chance of survival to ECMO weaning. Multiple organ dysfunction and a high PEEP were also predictive of a lower chance of hospital survival. Those with a confirmed diagnosis of viral myocarditis may require more medical attention due to the higher risk of hospital mortality than those without a definite diagnosis.

Hematological Abnormalities Beyond Lymphocytosis During Infectious Mononucleosis: Epstein-Barr Virus-Induced Thrombocytopenia

Background

Thrombocytopenia during Epstein-Barr virus mononucleosis is well-known; however, no recent series have investigated its frequency, associated factors, and evolution. The present study aimed to investigate platelet count characteristics in adult patients with infectious mononucleosis.

Methods

We reviewed the clinical records of 400 patients admitted to the hospital with infectious mononucleosis (52.0% male; median age, 19 years [range, 15-87 years]), focusing on blood platelet counts, thrombocytopenia prevalence and outcomes.

Results

Thrombocytopenia (platelet count ≤150 ×10⁹/L) was present in 119 (29.7%) patients. Thirty-two (8.0%) patients showed platelet counts lower than 100 ×10⁹/L. Thrombocytopenia was severe (platelets <50 ×10⁹/L) in 6 (1.5%) patients. Thrombocytopenia was associated with a lower frequency of typical mononucleosis symptoms such as sore throat and lymphadenopathy, lower frequency of positive heterophil antibodies, higher serum bilirubin concentration and prothrombin time, lower blood leukocyte and lymphocyte count, lower concentration of serum immunoglobulin G and immunoglobulin A concentrations, and larger spleen size. Thrombocytopenia normalized quickly during follow-up. Only 2 cases required specific therapy. Platelet counts significantly increased during follow-up, even in cases without baseline thrombocytopenia. There were no significant hemorrhagic complications.

Conclusions

Transient thrombocytopenia is common during infectious mononucleosis in adult patients. Patients with thrombocytopenia have distinct clinical and biological features; it is typically mild during infectious mononucleosis. Cases of severe thrombocytopenia are rare and were not associated with hemorrhagic complications in this series.

Review on the Biogenesis of Platelets in Lungs and Its Alterations in SARS-CoV-2 Infection Patients

Thrombocytes (platelets) are the type of blood cells that are involved in hemostasis, thrombosis, etc. For the conversion of megakaryocytes into thrombocytes, the thrombopoietin (TPO) protein is essential which is encoded by the TPO gene. TPO gene is present in the long arm of chromosome number 3 (3q26). This TPO protein interacts with the c-Mpl receptor, which is present on the outer surface of megakaryocytes. As a result, megakaryocyte breaks into the production of functional thrombocytes. Some of the evidence shows that the megakaryocytes, the precursor of thrombocytes, are seen in the lung's interstitium. This review focuses on the involvement of the lungs in the production of thrombocytes and their mechanism. A lot of findings show that viral diseases, which affect the lungs, cause thrombocytopenia in human beings. One of the notable viral diseases is COVID-19 or severe acute respiratory syndrome caused by SARS-associated coronavirus 2 (SARS-CoV-2). SARS-CoV-2 caused a worldwide alarm in 2019 and a lot of people suffered because of this disease. It mainly targets the lung cells for its replication. To enter the cells, these virus targets the angiotensin-converting enzyme-2 (ACE-2) receptors that are abundantly seen on the surface of the lung cells. Recent reports of COVID-19-affected patients reveal the important fact that these peoples develop thrombocytopenia as a post-COVID condition. This review elaborates on the biogenesis of platelets in the lungs and the alterations of thrombocytes during the COVID-19 infection.

Platelet-Derived Biomarkers: Potential Role in Early Pediatric Serious Bacterial Infection and Sepsis Diagnostics

Fever is the most common complaint of children who are attending a pediatric emergency department (PED). Most of the fever cases are of viral origin; however, the most common markers, such as leucocyte, neutrophil count, or C-reactive protein, are not sensitive or specific enough to distinguish the etiology of fever, especially if children present at the early phase of infection. Currently, platelets have been attributed a role as important sentinels in viral and bacterial infection pathogenesis. Thus, our aim was to analyze different platelet indices, such as PNLR (platelet-to-neutrophil/lymphocyte ratio), PNR (platelet-to-neutrophil ratio) as well as specific secreted proteins, such as sP-selectin, CXCL4, CXCL7, and serotonin. We included 68 children who were referred to PED with the early onset of fever (<12 h). All children with comorbidities, older than five years, and psychiatric diseases, who refused to participate were excluded. All the participants were divided into viral, bacterial, or serious bacterial infection (SBI) groups. All the children underwent blood sampling, and an additional sample was collected for protein analysis. Our analysis revealed statistically significant differences between leucocyte, neutrophil, and CRP levels between SBI and other groups. However, leucocyte and neutrophil counts were within the age norms. A higher PNLR value was observed in a bacterial group, PNR-in viral. As we tested CXCL7 and sP-selectin, alone and together those markers were statistically significant to discriminate SBI and sepsis from other causes of infection. Together with tachypnoe and SpO2 < 94%, it improved the prediction value of sepsis as well as SBI. CXCL4 and serotonin did not differ between the groups. Concluding, CXCL7 and sP-selectin showed promising results in early SBI and sepsis diagnosis.

The multifaceted role of platelets in mediating brain function

Platelets, the small, anucleate blood cells that originate from megakaryocytes in the bone marrow, are typically associated with coagulation. However, it is now apparent that platelets are more multifaceted than originally thought, with their function extending beyond their traditional role in hemostasis to acting as important mediators of brain function. In this review, we outline the broad repertoire of platelet function in the central nervous system, focusing on the similarities between platelets and neurons. We also summarize the role that platelets play in the pathophysiology of various neurological diseases, with a particular focus on neuroinflammation and neurodegeneration. Finally, we highlight the exciting prospect of harnessing the unique features of the platelet proteome and extracellular vesicles, which are rich in neurotrophic, antioxidative, and antiinflammatory factors, for the development of novel neuroprotective and neuroregenerative interventions to treat various neurodegenerative and traumatic pathologies.

Severe Thrombocytopenia Associated with Dengue Fever: An Evidence-Based Approach to Management of Thrombocytopenia

Dengue is a mosquito-borne viral illness common in tropical and subtropical countries but very rare in the United States. Patients infected with dengue often present with thrombocytopenia. In the setting of dengue, platelet transfusions as a treatment for thrombocytopenia have no clear benefits in reduction of severe bleeding or improvement of the platelet count. Here, we present a case of a traveler infected with dengue virus and discuss the approach to treat thrombocytopenia.

Serum Markers Associated with Disease Severity in a Bosnian Hemorrhagic Fever with Renal Syndrome Cohort

Puumala orthohantavirus (PUUV) is endemic in Europe and can cause hemorrhagic fever with renal syndrome (nephropathia epidemica). Disease features include fever, thrombocytopenia, and acute kidney injury (AKI). This retrospective cohort study of forty PUUV patients aims to characterize associations of serum immunological, hemostatic or kidney injury markers to disease severity. While interleukin-18 (IL-18) was significantly increased in severely thrombocytopenic patients (<100 × 109 platelets/L) compared to patients with higher platelet counts, RANTES was significantly decreased in these patients. These data suggest that patients with significant thrombocytopenia might have experienced pronounced Th1 immune responses. When kidney dysfunction was used as the primary disease outcome, recently identified AKI biomarkers (Cystatin C, insulin-like growth factor-binding protein 7, Nephrin, and trefoil factor 3) were significantly upregulated in patients with severe PUUV infection, defined as the estimated glomerular filtration rate (eGFR) below 30 m/min/1.73 m2. The increased expression of these markers specifically indicates pathology in glomeruli and proximal tubuli. Furthermore, E-selectin was significantly higher while interferon gamma-induced protein 10 (IP-10) was significantly lower in PUUV patients with more severe kidney dysfunction compared to patients with higher eGFR-values. Increased E-selectin illustrates the central role of endothelial cell activation, whereas decreased IP-10 could indicate a less important role of this cytokine in the pathogenesis of kidney dysfunction.

Dengue Virus and Platelets: From the Biology to the Clinic

Dengue is one of the most important vector-borne viral illnesses found in tropical and subtropical regions. Colombia has one of the highest rates of dengue cases in the Americas. Severe dengue virus (DENV) infection presents with capillary leakage, hemorrhage, and organ compromise, eventually leading to death. Over the years, there have been many efforts to develop a vaccine that guarantees protective immunity, but they have been partially successful, as such immunity would need to guarantee protection against four distinct viral serotypes. Absolute platelet count is a laboratory parameter used to monitor the clinical progression of DENV, as infection is often accompanied by thrombocytopenia. Although this finding is well described with respect to the natural history of the disease, there are various hypotheses as to the cause of this rapid decrease, and several in vivo and ex vivo models have been used to explain the effect of DENV infection on platelets and their precursors. DENV infects and activates platelets, facilitating their elimination through recognition by phagocytic cells and peripheral margination. However, infection also affects the precursors in the bone marrow by modulating megakaryopoiesis. The objective of this article is to explore various proposed mechanisms of DENV-induced thrombocytopenia to better understand the pathophysiology and clinical presentations of this highly relevant viral infection.

The Development of Immune Thrombocytopenia Due to COVID-19 Presenting as Menorrhagia

Immune thrombocytopenia (ITP), also known as immune thrombocytopenic purpura, is a hematological disorder characterized by a decreased platelet count, predisposing patients to bleeding. Coronavirus disease 2019 (COVID-19) has been linked to multiple cases of newly diagnosed ITP and is usually found in moderate-to-severe infections, peaking in children and elderly adults. Menorrhagia is the medical term for menstrual periods with abnormally heavy or prolonged bleeding occurring at regular intervals or prolonged uterine bleeding lasting more than seven days. Here, we report the case of a 23-year-old African American female who presented with the chief complaint of menorrhagia and was subsequently diagnosed as having ITP induced by an asymptomatic COVID-19 infection.

Carica papaya ameliorates thrombocytopenia through upregulation of Interleukin-11 and modulation of thrombopoietin in mouse model of carboplatin-induced myelosuppression

INTRODUCTION

Carica papaya L. (C. papaya) is used as a folk medicine for the treatment of various diseases throughout the world. Recently, papaya leaves decoction has been effectively used for the prevention and treatment of thrombocytopenia. The current study was undertaken to evaluate the thrombopoietic and immunomodulatory activities of C. papaya leaves in the mouse model of carboplatin induced myelosuppression.

METHODS

Myelosuppression was induced by a single intraperitoneal injection of carboplatin (125 mg/kg b. w.). Aqueous extract of C. papaya leaves (15 mg/kg b. w.) was given orally by feeding tube from day 0-18 to preventive group to see the preventive effect and from day 6-18 to treatment group for treatment effect.

RESULTS

The results showed that the C. papaya leaves extract significantly decreased the fall in platelet count in preventive and treatment groups. Extract significantly prevented the fall in total WBCs count on day 12 and 18 in the preventive group, whereas it significantly elevated the WBCs count in treatment group on day 18. Significantly increased RBCs count in both groups was observed on day 18 after treatment with C. papaya leaves extract. Treatment with C. papaya leaves extract significantly upregulated the mRNA expression levels of thrombopoietic cytokine IL-11 in both preventive and treatment groups. It is also observed that restoration of normal platelet count might have been resulted owing to the synergistic effect of upregulated IL-11 which ultimately led to a significantly diminished TPO expression.

CONCLUSION

Our data suggest that aqueous extract of C. papaya leaves possesses significant preventive and curative properties against thrombocytopenia.

Platelet-HIV: interactions and their implications

While it is clear that platelets interact with viruses, the ramifications and mechanisms of those interactions are still being defined for each type of viral infection. HIV/AIDS⁺ represents a potentially unique example of how viremia affects platelets since the increasing efficacy of antiretroviral therapeutics (ART) has made it a chronic disease that increases the risk of cardiovascular disease. In this opinion article, we discuss some of the open questions about how platelets interact with HIV. What happens to a virion once it binds a platelet? What is the nature of virus-induced platelet activation? Are platelets a normal part of the immune response to viremia that has been co-opted to increase the spread of HIV? The answers to these and similar questions will help define how platelet-directed therapeutics might be used in treating HIV/AIDS⁺ patients.

COVID-19-A Trigger Factor for Severe Immune-Mediated Thrombocytopenia in Active Rheumatoid Arthritis

Thrombocytopenia is defined as a platelet count below 150,000/mm³ for adults. There is still controversy about whether individuals with platelet counts of 100,000/mm³ to 150,000/mm³ should be classified as having genuine thrombocytopenia or borderline thrombocytopenia. Thrombocytopenia is considered mild when the platelet count is between 70,000 and 150,000/mm³ and severe if the count is less than 20,000/mm³. Thrombocytopenia in rheumatoid arthritis is a rare complication, with an incidence estimated between 3 and 10%. The main etiological aspects include drug-induced thrombocytopenia and immune thrombocytopenic purpura. The most common hematological abnormalities in SARS-CoV-2 infection are lymphopenia and thrombocytopenia. It has been observed that the severity of thrombocytopenia correlates with the severity of the infection, being a poor prognosis indicator and a risk factor for mortality. COVID-19 can stimulate the immune system to destroy platelets by increasing the production of autoantibodies and immune complexes. Autoimmunity induced by viral infections can be related to molecular mimicry, cryptic antigen expression and also spreading of the epitope. During the COVID-19 pandemic, it is of great importance to include the SARS-CoV-2 infection in differential diagnoses, due to the increased variability in forms of presentation of this pathology. In this review, our aim is to present one of the most recently discovered causes of thrombocytopenia, which is the SARS-CoV-2 infection and the therapeutic challenges it poses in association with an autoimmune disease such as rheumatoid arthritis.

The Use of Clinical Scores in the Management of Immune Thrombocytopenic Purpura in Children

While the majority of children with recently diagnosed ITP have a benign, self-limiting condition, most often with a spontaneously recovery, 40% of children with ITP progress toward persistent ITP and 10-20% goes toward chronicity. Several clinical scores have been developed with the aim to perform a better monitoring outcome or to differentiate transient vs. persistent ITP (e.g., Donato score). Our paper aims to describe and to compare the most important scores used in the management of ITP in children: bleeding severity scores and chronicity prediction scores. These scores include a combination of different already known risk factors: age, gender, presence of a previous infections or vaccination, bleeding grade, type of onset, platelet count at diagnosis. The real utility of these scores has been a matter of debate and no consensus has been reached so far as to their necessity to be implemented as compulsory tool in the care of children with ITP.

Platelets in COVID-19 disease: friend, foe, or both?

Immuno-thrombosis of COVID-19 results in the activation of platelets and coagulopathy. Antiplatelet therapy has been widely used in COVID-19 patients to prevent thrombotic events. However, recent analysis of clinical trials does not support the major effects of antiplatelet therapy on mortality in hospitalized COVID-19 patients, despite the indisputable evidence for an increased risk of thrombotic complications in COVID-19 disease. This apparent paradox calls for an explanation. Platelets have an important role in sensing and orchestrating host response to infection, and several platelet functions related to host defense response not directly related to their well-known hemostatic function are emerging. In this paper, we aim to review the evidence supporting the notion that platelets have protective properties in maintaining endothelial barrier integrity in the course of an inflammatory response, and this role seems to be of particular importance in the lung. It might, thus, well be that the inhibition of platelet function, if affecting the protective aspect of platelet activity, might diminish clinical benefits resulting from the inhibition of the pro-thrombotic phenotype of platelets in immuno-thrombosis of COVID-19. A better understanding of the platelet-dependent mechanisms involved in the preservation of the endothelial barrier is necessary to design the antiplatelet therapeutic strategies that inhibit the pro-thrombotic activity of platelets without effects on the vaso-protective function of platelets safeguarding the pulmonary endothelial barrier during multicellular host defense in pulmonary circulation.

Magnitude and Associated Factors of Thrombocytopenia among Pregnant Women Attending Antenatal Care Clinics at Dessie Comprehensive Specialized Hospital, Northeast Ethiopia

BACKGROUND

Thrombocytopenia is a common hematological abnormality during gestation. Pregnant women with severe thrombocytopenia may be associated with a higher risk of excessive bleeding during or after delivery. Therefore, the main aim of this study was to assess the magnitude and associated factors of thrombocytopenia among pregnant women attending antenatal care services at Dessie comprehensive and specialized hospital, Northeast Ethiopia.

METHODS

An institution-based cross-sectional study was conducted from February to March 2021. Using a systematic random sampling technique, a total of 294 pregnant women were enrolled in the study. Structured interviewer-administered questionnaires were used to collect socio-demographic and clinical data of study participants. Four ml of venous blood were collected from each pregnant woman and a complete blood count was determined using DIRUI BF 6500 automated hematology analyzer. Data were entered into Epidata version 4.6.0 and then exported into SPSS version 24.0. Multivariate logistic regression was used to assess the association between dependent and independent variables. P-value < 0.05 was considered to be statistically significant.

RESULTS

A total of 294 pregnant women who visited antenatal care services at Dessie comprehensive specialized hospital were included. The mean (±SD) age of the study participants was 29.7 (±6.1) years. The prevalence of thrombocytopenia among pregnant women was 9.9% (95% CI: 6.5, 13.6). A mild type of thrombocytopenia is the major type and accounted for 72.4% whereas moderate thrombocytopenia and severe thrombocytopenia accounted for 17.2% and 10.4% respectively among pregnant women. Multivariate logistic regression showed that urban residents (AOR: 0.206,95% CI, 0.055-0.748), gestational ages within the first trimester (AOR: 0.183, 95% CI, 0.057-0.593) and gestational ages within the second trimester (AOR = 0.264, 95% CI, 0.092-0.752) were significantly associated and independent predictors of thrombocytopenia in pregnant women.

CONCLUSION

In this study, the prevalence of thrombocytopenia was 9.9% and the mild type of thrombocytopenia (72.4%) was higher than the other type of thrombocytopenia among pregnant women. In multivariate logistic regression analysis, residence and gestational age (trimester) were significantly associated with thrombocytopenia. Therefore, the platelet count should be routinely determined during the antenatal care visit for proper diagnosis and to minimize bleeding during and or after childbirth.

Platelets in the pathogenesis of flavivirus disease

Research on the role of platelets in modulating innate and adaptive host immune responses has gaining importance in the last two decades. Since the virus can directly interact with platelet receptors and modulate the host immune response, understanding the role of platelets in viral pathogenesis would pave way for novel therapeutic means. The present review aims at presenting the important molecular aspects of platelet-flavivirus interactions and how it leads to platelet activation, thrombocytopenia, and vascular endothelial leakage. Besides, the role of some of the platelet-derived factors as biomarkers for the early prediction of disease outcome taking dengue infection as an example is reviewed.

Fundamentals in Covid-19-Associated Thrombosis: Molecular and Cellular Aspects

The novel coronavirus disease (COVID-19) is associated with a high incidence of coagulopathy and venous thromboembolism that may contribute to the worsening of the clinical outcome in affected patients. Marked increased D-dimer levels are the most common laboratory finding and have been repeatedly reported in critically ill COVID-19 patients. The infection caused by Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) is followed by a massive release of pro-inflammatory cytokines, which mediate the activation of endothelial cells, platelets, monocytes, and neutrophils in the vasculature. In this context, COVID-19-associated thrombosis is a complex process that seems to engage vascular cells along with soluble plasma factors, including the coagulation cascade, and complement system that contribute to the establishment of the prothrombotic state. In this review, we summarize the main findings concerning the cellular mechanisms proposed for the establishment of COVID-19-associated thrombosis.

A review of severe thrombocytopenia in Zika patients - Pathophysiology, treatment and outcome

BACKGROUND

During the 2015 Zika virus infection (ZVI) epidemic swiping through the Americas, few cases of ZVI with severe, potentially life-threatening thrombocytopenia were reported. Platelet transfusion, corticosteroids and intravenous immunoglobulins (IVIG) were in most cases applied as therapeutic options, predominantly with success. We present a comprehensive overview concerning the pathophysiology, treatment strategies and outcomes of patients with ZVI and severe thrombocytopenia (platelet count <50 × 10⁹/L).

METHOD

A literature search was performed.

RESULTS

Eleven case reports and case series with a total of 28 patients met the inclusion criteria; including five cases with lethal outcome. Therapeutic strategies, including platelet transfusion, administration of steroids and/or IVIG were described in 24 cases.

CONCLUSIONS

Severe thrombocytopenia is a rare, but potentially life-threatening complication of ZVI. The principal pathophysiological mechanism appears to immune-induced thrombocytopenia. Due to a paucity of cases, the optimal treatment strategy remains to be elucidated.

Effectiveness of COVID-19 vaccines and their challenges (Review)

At the end of 2019, a new disease recognized such as severe acute respiratory syndrome (SARS), was reported in Wuhan, China. This disease was caused by an unknown SARS coronavirus 2 (SARS-CoV-2); a virus is characterized by high infectivity among humans. In some cases, this disease can be asymptomatic, while in other cases can induce flu-like symptoms or acute respiratory distress syndrome, pneumonia and death. For this reason, the World Health Organization and Public Health Emergency of International Concern declared a pandemic status in January 2020. Currently, numerous countries have been involved in the development of effective vaccines to protect humans against SARS-CoV-2 infection. The present review will discuss the four vaccines, AZD1222 (AstraZeneca or Vaxzevria), Janssen (Ad26.COV2.S), Moderna/mRNA-1273 and BioNTech/Fosun/Pfizer BNT162b1, that are currently in use worldwide to understand their efficacy, but also evaluate the difficulties and challenges of vaccine development. Although several questions should be addressed regarding these vaccines, the current review will examine the viral elements used in the coronavirus-19 vaccine that can play a crucial role in inducing a strong immune response, as well as the different adverse effects that they can cause to individuals.

Association of bleeding symptoms during influenza infection and administered drugs

On March 1, 2019, the Ministry of Health, Labour and Welfare added bleeding symptoms to adverse reaction package inserts as a possible adverse event for a new anti-influenza drug, baloxavir marboxil, because 13 patients with bleeding symptoms were identified among influenza patients taking the drug. Nevertheless, aspects of the epidemiology of bleeding symptoms among influenza patients remain unclear. This study elucidated bleeding symptoms among influenza patients and hospitalized patients as severe cases. A survey was administered to all physicians in Japan during the 2019-2020 season for reporting of bleeding symptoms in influenza patients. The survey elicited information about outcomes, assuming associated underlying diseases and drugs in addition to administered drugs including acetaminophen and anti-influenza (antiviral) drugs. We received reports of 63 cases with bleeding symptoms, including 5 cases of hospitalized patients. Among all patients, 54% had been administered oseltamivir; 10% had been administered baloxavir marboxil. Among hospitalized patients, all had been administered acetaminophen; 40% of them had been administered oseltamivir, and one patient had been administered baloxavir marboxil. Accumulation of bleeding symptom cases is expected to be necessary to evaluate the association.

To clot or not to clot? Ad is the question-Insights on mechanisms related to vaccine-induced thrombotic thrombocytopenia

Vaccine-induced immune thrombotic thrombocytopenia (VITT) has caused global concern. VITT is characterized by thrombosis and thrombocytopenia following COVID-19 vaccinations with the AstraZeneca ChAdOx1 nCov-19 and the Janssen Ad26.COV2.S vaccines. Patients present with thrombosis, severe thrombocytopenia developing 5-24 days following first dose of vaccine, with elevated D-dimer, and PF4 antibodies, signifying platelet activation. As of June 1, 2021, more than 1.93 billion COVID-19 vaccine doses had been administered worldwide. Currently, 467 VITT cases (0.000024%) have been reported across the UK, Europe, Canada, and Australia. Guidance on diagnosis and management of VITT has been reported but the pathogenic mechanism is yet to be fully elucidated. Here, we propose and discuss potential mechanisms in relation to adenovirus induction of VITT. We provide insights and clues into areas warranting investigation into the mechanistic basis of VITT, highlighting the unanswered questions. Further research is required to help solidify a pathogenic model for this condition.

Role of SARS-CoV-2 -induced cytokines and growth factors in coagulopathy and thromboembolism

Severe COVID-19 patients frequently present thrombotic complications which commonly lead to multiorgan failure and increase the risk of death. Severe SARS-CoV-2 infection induces the cytokine storm and is often associated with coagulation dysfunction. D-dimer, a hallmark of venous thromboembolism (VTE), is observed at a higher level in the majority of hospitalized COVID-19 patients. The precise molecular mechanism of the disproportionate effect of SARS-CoV-2 infection on the coagulation system is largely undefined. SARS-CoV-2 -induced endotheliopathy and, induction of cytokines and growth factors (GFs) most likely play important roles in platelet activation, coagulopathy, and VTE. Generally, viral infections lead to systemic inflammation and induction of numerous cytokines and GFs and many of them are reported to be associated with increased VTE. Most importantly, platelets play key thromboinflammatory roles linking coagulation to immune mediators in a variety of infections including response to viral infection. Since the pathomechanism of coagulopathy and VTE in COVID-19 is largely undefined, herein we highlight the association of dysregulated inflammatory cytokines and GFs with thrombotic complications and coagulopathy in COVID-19.

Recent Advances in the Discovery and Function of Antimicrobial Molecules in Platelets

The conventional function described for platelets is maintaining vascular integrity. Nevertheless, increasing evidence reveals that platelets can additionally play a crucial role in responding against microorganisms. Activated platelets release molecules with antimicrobial activity. This ability was first demonstrated in rabbit serum after coagulation and later in rabbit platelets stimulated with thrombin. Currently, multiple discoveries have allowed the identification and characterization of PMPs (platelet microbicidal proteins) and opened the way to identify kinocidins and CHDPs (cationic host defense peptides) in human platelets. These molecules are endowed with microbicidal activity through different mechanisms that broaden the platelet participation in normal and pathologic conditions. Therefore, this review aims to integrate the currently described platelet molecules with antimicrobial properties by summarizing the pathways towards their identification, characterization, and functional evaluation that have promoted new avenues for studying platelets based on kinocidins and CHDPs secretion.