The terms microparticles (MPs) and microvesicles (MVs) refer to large extracellular vesicles (EVs) generated from a broad spectrum of cells upon its activation or death by apoptosis. The unique surface antigens of MPs/MVs allow for the identification of their cellular origin as well as its functional characterization. Two basic aspects of MP/MV functions in physiology and pathological conditions are widely considered. Firstly, it has become evident that large EVs have strong procoagulant properties. Secondly, experimental and clinical studies have shown that MPs/MVs play a crucial role in the pathophysiology of inflammation-associated disorders. A cardinal feature of these disorders is an enhanced generation of platelets-, endothelial-, and leukocyte-derived EVs. Nevertheless, anti-inflammatory effects of miscellaneous EV types have also been described, which provided important new insights into the large EV-inflammation axis. Advances in understanding the biology of MPs/MVs have led to the preparation of this review article aimed at discussing the association between large EVs and inflammation, depending on their cellular origin.

Infection with severe acute respiratory syndrome coronavirus 2 (SARS–CoV–2) is a rapidly spreading and devastating global pandemic. Many researchers are attempting to clarify the mechanisms of infection and to develop a drug or vaccine against the virus, but there are still no proven effective treatments. The present article reviews the common presenting hematological manifestations of coronavirus disease 2019 (COVID–19). Elucidating the changes in hematological parameters in SARS–CoV–2 infected patients could help to understand the pathophysiology of the disease and may provide early clues to diagnosis. Several studies have shown that hematological parameters are markers of disease severity and suggest that they mediate disease progression.

Objectives: Symptomatic hemorrhagic transformation (sHT) is a life-threatening complication of acute ischemic stroke (AIS). The early identification of the patients at increased risk of sHT can have clinically relevant implications. The aim of this study was to explore the validity and accuracy of the neutrophil-to-lymphocyte ratio (NLR) in predicting sHT in patients with AIS undergoing revascularization. Methods: Consecutive patients hospitalized for AIS who underwent intravenous thrombolysis, mechanical thrombectomy or both were identified. The NLR values were estimated at admission. The study endpoint was the occurrence of sHT within 24 h from stroke treatment. Results: Fifty-one patients with AIS were included, with a median age of 67 (interquartile range, 55–78) years. sHT occurred in 10 (19.6%) patients. Patients who developed sHT had higher NLR at admission. NLR was an independent predictor of sHT and showed good discriminatory power (area under the curve 0.81). In a multivariable analysis, NLR and systolic blood pressure were independently associated with sHT. Conclusions: NLR at admission can accurately predict sHT in patients with AIS undergoing revascularization.

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Iron is found in almost all foods, so dietary iron intake is related to energy intake. However, its availability for absorption is quite variable, and poor bioavailability is a major reason for the high prevalence of nutritional iron deficiency anaemia. Absorption occurs primarily in the proximal small intestine through mature enterocytes located at the tips of the duodenal villi. Two transporters: Hem Carrier Protein 1 (HCP1) and Divalent Metal Transporter 1 (DMT1) appear to mediate the entry of most if not all dietary iron into these mucosal cells. Absorption is regulated according to the body's needs. The results of studies suggest that iron absorption is regulated by the control of iron export from duodenal enterocytes to the circulating transferrin pool by ferroportin. Hepcidin, a 25-amino acid polypeptide, which is synthesised primarily in hepatocytes, reduces the iron absorption from the intestine by binding to the only known cellular iron exporter, ferroportin, causing it to be degraded. Therefore, hepcidin is now considered to be the most important factor controlling iron absorption.

Haemostatic unbalance is often observed in patients with coronavirus disease 2019 (COVID-19), and patients with severe disease are at high risk of developing thromboembolic complications. Viscoelastic methods (VEMs), including thrombelastography (TEG) and thromboelastometry (TEM), provide data on the nature of haemostatic disturbance. In this systematic review, we assessed the performance of TEG and TEM in the assessment of blood coagulation and fibrinolysis in patients with COVID-19. PubMed, Scopus, Web of Science Core Collection, medRxiv and bioRxiv were systematically searched for clinical studies evaluating TEG and/or TEM variables in COVID-19 individuals. Ten studies, with a total of 389 COVID-19 patients, were included, and VEMs were performed in 292 of these patients. Most patients (90%) presented severe COVID-19 and required mechanical ventilation. TEG and TEM variables showed that these patients displayed hypercoagulability and fibrinolysis shutdown, despite the use of appropriate thromboprophylaxis. However, the mechanism underlying these phenomena and their clinical significance in COVID-19 patients who developed thrombosis, is still not clear. Further studies are warranted if VEMs might help to identify those at highest risk of thrombotic events and who therefore may derive the greatest benefit from antithrombotic therapy.

Our findings suggest that patients with acute ischaemic stroke have increased generation of MPs-TF. Nevertheless, further studies are needed in order to confirm such inference.

Background and Objectives: Ischaemic stroke (IS) is the leading cause of death and disability worldwide. All stages of cerebral ischaemia, but especially acute phase, are associated with inflammatory response. Recent studies showed that neutrophil-to-lymphocyte ratio (NLR) and lymphocyte-to-monocyte ratio (LMR) may be used to assess inflammation in IS. To test whether there is a relationship between these parameters and type of stroke treatment, we analysed NLR and LMR in IS patients treated with three different modalities. Materials and Methods: The study included 58 adults with acute IS. A total of 28 patients received intravenous thrombolysis. In another 10 patients, the thrombolytic therapy was followed by thrombectomy and 20 patients did not undergo causal treatment. Blood samples were obtained within 24 h of the stroke diagnosis to calculate NLR and LMR. Next, NLR and LMR of the study subgroups were compared. Results: Our study revealed that NLR was significantly higher in patients treated with thrombectomy following thrombolysis, compared to no causal treatment. Statistical analysis demonstrated that patients with high National Institutes of Health Stroke Scale (NIHSS) scores presented higher NLR than in those with low NIHSS scores. Additionally, patients with high-sensitivity C-reactive protein (hs-CRP) ≥ 3 mg/L presented with significantly higher NLR and significantly lower LMR than the group of patients with lower hs-CRP (<3 mg/L). Conclusions: The main finding of this pilot study was that NLR in IS patients treated using thrombectomy following thrombolysis was markedly higher than that in other treatment groups, which was associated with increased severity of the disease in these patients. Therefore, patients with higher NLR may be expected to have more severe stroke. The link between stroke severity and NLR deserves further study.