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Vascular endothelial growth factor C (Vegfc) is crucial for lymphatic and blood vessel development, yet its cellular sources and specific functions in heart development remain unclear. To address this, we created a vegfc reporter and an inducible overexpression line in zebrafish. We found vegfc expression in large coronary arteries, circulating thrombocytes, cardiac adipocytes, and outflow tract smooth muscle cells. Notably, although coronary lymphangiogenesis aligns with Vegfc-expressing arteries in juveniles, it occurs only after coronary artery formation. Vegfc overexpression induced ectopic lymphatics on the ventricular surface prior to arterial formation, indicating that Vegfc abundance, rather than arterial presence, drives lymphatic development. However, this overexpression did not affect coronary artery coverage, suggesting a specific role for Vegfc in lymphatic, rather than arterial, development. Thrombocytes emerged as the initial Vegfc source during inflammation following heart injuries, transitioning to endocardial and myocardial expression during regeneration. Lower Vegfc levels in an amputation model corresponded with a lack of lymphatic expansion. Importantly, Vegfc overexpression enhanced lymphatic expansion and promoted scar resolution without affecting cardiomyocyte proliferation, highlighting its role in regulating lymphangiogenesis and promoting heart regeneration. [ABSTRACT FROM AUTHOR]

Thrombocytopenia represents one of the most frequent causes of addressability for a hematological consultation. The purpose of the study is to establish a correlation between the degree of thrombocytopenia and the appearance of the mucocutaneous bleeding, with a therapeutic purpose. Materials and method: Our study is a retrospective observational study and was carried out on a group of 100 patients who were referred to the Hematology Clinic of Sp. St. Spiridon, Iași for a period of 12 months and who presented with isolated thrombocytopenia on admission. Other coagulopathy evolving with thrombocytopenia were excluded. To establish the correlation between the decrease in the number of platelets and the appearance of the hemorrhagic skin-mucosal syndrome, statistical methods were used – F Test – Two sample for Variance. Results and discussions: Thrombocytopenia was defined as the value of platelets below 150,000\mmc. 5 grades of thrombocytopenia were established: grade I (TR=150,000-100,000/mmc), grade II (TR= 100,000-50,000/mmc), grade III (TR=50,000-20,000/mmc), grade IV (TR= 20,000 -10,000/mmc), grade V (TR below 10,000/mmc)40% of the patients included in the study presented thrombocytopenia gr. I, 24% – grade II, 15% – grade III, 6% – grade IV and 15% presented severe thrombocytopenia (grade V). The mucocutaneous bleeding was manifested by: petechiae and ecchymosis, epistaxis, bleeding in the oral cavity (gingival bleeding, hemorrhagic bullae), menometrorrhagia, hematuria, melena. There is a statistical correlation between the number of platelets and the occurrence of mucocutaneous bleeding: p=0.000121 (p less than 0.001). The first clinical manifestations of the mucocutaneous bleeding appeared at the value of 70,000/mmc. No statistical correlation was obtained between the age of the patients and the number of platelets (p=0.0352). Conclusions: The occurrence of mucocutaneous bleeding is directly related to the decrease in the number of platelets. The oral cavity usually is involved in bleeding caused by the decrease in the number of platelets and requires a multidisciplinary approach.

Introduction: Immune checkpoint inhibitors (ICIs) have revolutionized classical treatment approaches of various cancer entities, but are also associated with a number of side effects. One of these may be life-threatening clotting disorders with the risk of thrombotic or hemorrhagic complications, the mechanisms of which are still poorly understood. In the present study, we analyzed the direct effects of pembrolizumab, nivolumab, and ipilimumab on platelet aggregation as well as plasma coagulation followed by fibrinolysis in an ex vivo model. Methods: Microplate spectrometry was used to analyze aggregation, coagulation, and fibrinolysis in platelet-free (PFP) and platelet-rich (PRP) healthy donor plasma samples treated with pembrolizumab, nivolumab, ipilimumab, and appropriate isotype controls. Aggregation was induced by TRAP-6. Clotting of PFP and PRP followed by lysis was initiated with a tissue factor in a mixture of phosphatidylserine:phosphatidylcholine and the addition of t-PA. Among other parameters, the area under the curve (AUC) was used to compare the effect of ICIs on aggregation, coagulation, and fibrinolysis. Results: Upon direct contact with platelets, pembrolizumab stimulated platelet aggregation in PRP, while nivolumab and ipilimumab promoted disaggregation with corresponding changes in the AUC. Pembrolizumab and nivolumab, both PD-1 receptor inhibitors, had no effect on the plasma coagulation cascade. Ipilimumab, a CTLA-4 receptor inhibitor, significantly increased the rate of PRP clotting. When clotting was followed by lysis, all ICIs were found to prolong the growth of the PRP-derived fibrin clot and delay its elimination. This was manifested by an increase in AUC relative to control PRP. Conclusion: This study characterizes the potential impact of pembrolizumab, nivolumab, and ipilimumab on hemostasis. Nivolumab and ipilimumab are able to reduce aggregation and increase the procoagulant properties of platelets, which can cause side effects associated with hemostatic imbalance leading to thrombosis or bleeding. The observed ICI-specific effects may contribute to our understanding of the mechanisms by which ICI affects platelets and suggest how, in a clinical setting, to reduce coagulation disorders during ICI treatment in the future. [ABSTRACT FROM AUTHOR]

Abstract Background Platelets stored at 1–6 °C are hypothesized to be more hemostatically active than standard room temperature platelets (RTP) stored at 20–24 °C. Recent studies suggest converting RTP to cold-stored platelets (Delayed Cold-Stored Platelets, DCSP) may be an important way of extending platelet lifespan and increasing platelet supply while also activating and priming platelets for the treatment of acute bleeding. However, there is little clinical trial data supporting the efficacy and safety of DCSP compared to standard RTP. Methods This protocol details the design of a multicentre, two-arm, parallel-group, randomized, active-control, blinded, internal pilot trial to be conducted at two cardiac surgery centers in Canada. The study will randomize 50 adult (≥ 18 years old) patients undergoing at least moderately complex cardiac surgery with cardiopulmonary bypass and requiring platelet transfusion to receive either RTP as per standard of care (control group) or DCSP (intervention group). Patients randomized to the intervention group will receive ABO-identical, buffy-coat, pathogen-reduced, platelets in platelet additive solution maintained at 22 °C for up to 4 days then placed at 4 °C for a minimum of 24 h, with expiration at 14 days after collection. The duration of the intervention is from the termination of cardiopulmonary bypass to 24 h after, with a maximum of two doses of DCSP. Thereafter, all patients will receive RTP. The aim of this pilot is to assess the feasibility of a future RCT comparing the hemostatic effectiveness of DCSP to RTP (defined as the total number of allogeneic blood products transfused within 24 h after CPB) as well as safety. Specifically, the feasibility objectives of this pilot study are to determine (1) recruitment of ≥ 15% eligible patients per center per month); (2) appropriate platelet product available for ≥ 90% of patients randomized to the cold-stored platelet group; (3) Adherence to randomization assignment (> 90% of patients administered assigned product). Discussion DCSP represents a promising logistical solution to address platelet supply shortages and a potentially more efficacious option for the management of active bleeding. No prospective clinical studies on this topic have been conducted. This proposed internal pilot study will assess the feasibility of a larger definitive study. Trial registration NCT 06147531 (clinicaltrials.gov).

Thrombocytopenia represents one of the most frequent causes of addressability for a hematological consultation. The purpose of the study is to establish a correlation between the degree of thrombocytopenia and the appearance of the mucocutaneous bleeding, with a therapeutic purpose. Materials and method: Our study is a retrospective observational study and was carried out on a group of 100 patients who were referred to the Hematology Clinic of Sp. St. Spiridon, Iași for a period of 12 months and who presented with isolated thrombocytopenia on admission. Other coagulopathy evolving with thrombocytopenia were excluded. To establish the correlation between the decrease in the number of platelets and the appearance of the hemorrhagic skin-mucosal syndrome, statistical methods were used - F Test - Two sample for Variance. Results and discussions: Thrombocytopenia was defined as the value of platelets below 150,000\mmc. 5 grades of thrombocytopenia were established: grade I (TR=150,000-100,000/mmc), grade II (TR= 100,000-50,000/mmc), grade III (TR=50,000-20,000/mmc), grade IV (TR= 20,000 -10,000/mmc), grade V (TR below 10,000/mmc)40% of the patients included in the study presented thrombocytopenia gr. I, 24% - grade II, 15% - grade III, 6% - grade IV and 15% presented severe thrombocytopenia (grade V). The mucocutaneous bleeding was manifested by: petechiae and ecchymosis, epistaxis, bleeding in the oral cavity (gingival bleeding, hemorrhagic bullae), menometrorrhagia, hematuria, melena. There is a statistical correlation between the number of platelets and the occurrence of mucocutaneous bleeding: p=0.000121 (p less than 0.001). The first clinical manifestations of the mucocutaneous bleeding appeared at the value of 70,000/mmc. No statistical correlation was obtained between the age of the patients and the number of platelets (p=0.0352). Conclusions: The occurrence of mucocutaneous bleeding is directly related to the decrease in the number of platelets. The oral cavity usually is involved in bleeding caused by the decrease in the number of platelets and requires a multidisciplinary approach. [ABSTRACT FROM AUTHOR]

Background: Platelets stored at 1–6 °C are hypothesized to be more hemostatically active than standard room temperature platelets (RTP) stored at 20–24 °C. Recent studies suggest converting RTP to cold-stored platelets (Delayed Cold-Stored Platelets, DCSP) may be an important way of extending platelet lifespan and increasing platelet supply while also activating and priming platelets for the treatment of acute bleeding. However, there is little clinical trial data supporting the efficacy and safety of DCSP compared to standard RTP. Methods: This protocol details the design of a multicentre, two-arm, parallel-group, randomized, active-control, blinded, internal pilot trial to be conducted at two cardiac surgery centers in Canada. The study will randomize 50 adult (≥ 18 years old) patients undergoing at least moderately complex cardiac surgery with cardiopulmonary bypass and requiring platelet transfusion to receive either RTP as per standard of care (control group) or DCSP (intervention group). Patients randomized to the intervention group will receive ABO-identical, buffy-coat, pathogen-reduced, platelets in platelet additive solution maintained at 22 °C for up to 4 days then placed at 4 °C for a minimum of 24 h, with expiration at 14 days after collection. The duration of the intervention is from the termination of cardiopulmonary bypass to 24 h after, with a maximum of two doses of DCSP. Thereafter, all patients will receive RTP. The aim of this pilot is to assess the feasibility of a future RCT comparing the hemostatic effectiveness of DCSP to RTP (defined as the total number of allogeneic blood products transfused within 24 h after CPB) as well as safety. Specifically, the feasibility objectives of this pilot study are to determine (1) recruitment of ≥ 15% eligible patients per center per month); (2) appropriate platelet product available for ≥ 90% of patients randomized to the cold-stored platelet group; (3) Adherence to randomization assignment (> 90% of patients administered assigned product). Discussion: DCSP represents a promising logistical solution to address platelet supply shortages and a potentially more efficacious option for the management of active bleeding. No prospective clinical studies on this topic have been conducted. This proposed internal pilot study will assess the feasibility of a larger definitive study. Trial registration: NCT 06147531 (clinicaltrials.gov). [ABSTRACT FROM AUTHOR]

Introduction: Studies assessing the impact of preoperative and first-day postoperative values of leukocytes, thrombocytes, and platelet/leukocyte ratio (PLR) after radical cystectomy (RC) are sparse. We aimed to assess the impact of these factors on long-term survival after RC. Methods: An analysis of patients undergoing open RC from 2004 to 2023 at our center was performed. Leukocytosis was defined as ≥8,000 leukocytes/μL and thrombocytosis as ≥400,000 thrombocytes/μL. Similarly, the cutoff for PLR was set at 28. A multivariable Cox regression analysis was performed to assess the role of leukocytosis, thrombocytosis, and PLR on long-term survival after RC. For all analyses, hazard ratios (HRs) with the corresponding 95% confidence intervals (CIs) were estimated. Results: A total of 1,817 patients with a median age of 70 years (interquartile range [IQR]: 62–77) were included. Overall, 804 (44%), 175 (10%), and 1,296 (71%) patients presented with leukocytosis, thrombocytosis, and PLR ≥28 preoperatively. Accordingly, 1,414 (78%), 37 (2%), and 249 (14%) patients presented with leukocytosis, thrombocytosis, and PLR ≥28 on the first day after RC. At a median follow-up of 26 months (IQR: 8–68) after RC, 896 (49%) patients died. In the multivariate Cox regression analysis after adjusting for major perioperative risk factors, only preoperative leukocytosis (HR: 1.3, 95% CI: 1.1–1.6, p = 0.01), as well as both preoperative and first-day thrombocytosis (HR: 2.1, 95% CI: 1.5–2.9, and HR: 2.8, 95% CI: 1.6–5.1, p < 0.001, accordingly) were associated with worse overall survival. Conclusion: PLR should not be used as a prognostic marker for survival after RC. On the contrary, preoperative leukocytosis, as well as preoperative and first-day thrombocytosis should raise awareness among clinicians performing RC since they were independently associated with worse survival after RC. [ABSTRACT FROM AUTHOR]

Imaging flow cytometry is an attractive method to investigate individual cells by optical properties. However, imaging flow cytometry applications with clinical relevance are scarce so far. Platelet aggregation naturally occurs during blood coagulation to form a clot. However, aberrant platelet aggregation is associated with cardiovascular disease under steady‐state conditions in the blood. Several types of so‐called antiplatelet drugs are frequently described to reduce the risk of stroke or cardiovascular diseases. However, an efficient monitoring method is missing to identify the presence and frequency of platelet–platelet aggregates in whole blood on a single cell level. In this work, we employed imaging flow cytometry to identify fluorescently labeled platelets in whole blood with a conditional gating strategy. Images were post‐processed and aligned. A convolutional neural network was designed to identify platelet–platelet aggregates of two, three, and more than three platelets, and results were validated against various data set properties. In addition, the neural network excluded erythrocyte–platelet aggregates from the results. Based on the results, a parameter for detecting platelet–platelet aggregates, the weighted platelet aggregation, was developed. If employed on a broad scale with proband and patient samples, our method could aid in building a future diagnostic marker for cardiovascular disease and monitoring parameters to optimize drug prescriptions in such patient groups. [ABSTRACT FROM AUTHOR]

Extracellular sphingosine-1-phosphate (S1P) emerged as an important regulator of muscle function. We previously found that plasma S1P concentration is elevated in response to acute exercise and training. Interestingly, hypoxia, which is commonly utilized in training programs, induces a similar effect. Therefore, the aim of the current study was to determine the effect of normobaric hypoxia on exercise-induced changes in blood sphingolipid metabolism. Fifteen male competitive cyclists performed a graded cycling exercise until exhaustion (GE) and a simulated 30 km individual time trial (TT) in either normoxic or hypoxic (FiO2 = 16.5%) conditions. Blood samples were taken before the exercise, following its cessation, and after 30 min of recovery. We found that TT increased dihydrosphingosine-1-phosphate (dhS1P) concentration in plasma (both HDL- and albuminbound) and blood cells, as well as the rate of dhS1P release from erythrocytes, regardless of oxygen availability. Plasma concentration of S1P was, however, reduced during the recovery phase, and this trend was augmented by hypoxia. On the other hand, GE in normoxia induced a selective increase in HDL-bound S1P. This effect disappeared when the exercise was performed in hypoxia, and it was associated with reduced S1P level in platelets and erythrocytes. We conclude that submaximal exercise elevates total plasma dhS1P concentration via increased availability of dihydrosphingosine resulting in enhanced dhS1P synthesis and release by blood cells. Maximal exercise, on the other hand, induces a selective increase in HDL-bound S1P, which is a consequence of mechanisms not related to blood cells. We also conclude that hypoxia reduces post-exercise plasma S1P concentration. [ABSTRACT FROM AUTHOR]

Acute exacerbations (AE) are severe complications of chronic obstructive pulmonary disease (COPD); however, the need for biomarkers which predict them is still unmet. High platelet count (PLC) and platelet-to-lymphocyte ratio (PLR) are associated with higher mortality in patients with COPD. We investigated if PLC and PLR at the onset of a severe AE could predict the time of the next relapse. In a prospective observational cohort study, data of 152 patients hospitalized with AECOPD were collected, and patients were divided into PLC-low (<239 ​× ​109/L, n ​= ​51), PLC-medium (239-297 ​× ​109/L, n ​= ​51) and PLC-high (>297 ​× ​109/L, n ​= ​50) or PLR-low (<147, N ​= ​51), PLR-medium (147–295, n ​= ​51) and PLR high (>295, n ​= ​50) groups based on PLC and PLR tertiles using admission laboratory results. Clinical characteristics and the time to the next severe or moderate AE within 52 weeks were compared among subgroups using log-rank test. PLC and PLR tertiles did not differ in clinical characteristics or the time till the next AE (p ​> ​0.05). PLC and PLR showed a direct weak correlation to neutrophil count (Pearson r ​= ​0.26, p ​< ​0.01 and r ​= ​0.20, p ​= ​0.01) and PLC also demonstrated a weak relationship to white blood cell counts (Pearson r ​= ​0.29, p ​< ​0.001). However, PLR presented an inverse relationship to monocyte and eosinophil counts (r ​= ​−0.32, p ​< ​0.001 and r ​= ​−0.17, p ​= ​0.03). PLC and PLR do not predict the time till the next relapse; however, they may reflect on neutrophilic inflammatory response during an exacerbation of COPD. [ABSTRACT FROM AUTHOR]

Background: The clinical course of ischemic and hemorrhagic strokes can be influenced by the coagulation status of individual patients. The prior use of antiplatelet therapy (APT) such as acetylsalicylic acid (ASA) or P2Y12-antagonists has been inconsistently described as possibly increasing the risk of hemorrhagic transformation or expansion. Since clinical studies describing prior use of antiplatelet medication are overwhelmingly lacking specific functional tests, we aimed to implement testing in routine stroke care. Methods: We used fluorescence-activated cell sorting (FACS) with antibodies against CD61 for thrombocyte identification and CD62p or platelet activation complex-1 (PAC-1) to determine platelet activation. Aggregometry and automated platelet functioning analyzer (PFA-200) were employed to test thrombocyte reactivity. FACS and aggregometry samples were stimulated in vitro with arachidonic acid (AA) and adenosine diphosphate (ADP) to measure increase in CD62p-/PAC-1-expression or aggregation, respectively. Results: Between February and July 2023, 20 blood samples (n = 11 ischemic strokes; n = 7 hemorrhagic strokes; n = 2 controls) were acquired and analyzed within 24 h of symptom onset. N = 11 patients had taken ASA, n = 8 patients no APT and n = 1 ASA+clopidogrel. ASA intake compared to no APT was associated with lower CD62p expression after stimulation with AA on FACS analysis (median 15.8% [interquartile range {IQR} 12.6-37.2%] vs. 40.1% [IQR 20.3-56.3%]; p = 0.020), lower platelet aggregation (9.0% [IQR 7.0-12.0%] vs. 88.5% [IQR 11.8-92.0%]; p = 0.015) and longer time to plug formation with PFA-200 (248.0 s [IQR 157.0-297] vs. 121.5 s [IQR 99.8-174.3]; p = 0.027). Significant correlations were noted between AA-induced CD62p expression and aggregometry analysis (n = 18; ρ = 0.714; p < 0.001) as well as a negative correlation between CD62p increase and PFA clot formation time (n = 18; ρ = -0.613; p = 0.007). Sensitivity for ASA intake was highest for PFA (81.8% for values ≥155.5 s). The combination of ASA + clopidogrel also affected ADP-induced CD62p and PAC-1 expression. Conclusion: In the clinical setting it is feasible to use differentiated platelet analytics to determine alterations caused by antiplatelet therapy. Among the tests under investigation, PFA-200 showed the highest sensitivity for the intake of ASA in stroke patients. FACS analysis on the other hand might be able to provide a more nuanced approach to altered platelet reactivity. [ABSTRACT FROM AUTHOR]

Extracellularsphingosine-1-phosphate (S1P) emerged as an important regulator of muscle function. We previously found that plasma S1P concentration is elevated in response to acute exercise and training. Interestingly, hypoxia, which is commonly utilized in training programs, induces a similar effect. Therefore, the aim of the current study was to determine the effect of normobaric hypoxia on exercise-induced changes in blood sphingolipid metabolism. Fifteen male competitive cyclists performed a graded cycling exercise until exhaustion (GE) and a simulated 30 km individual time trial (TT) in either normoxic or hypoxic (FiO 2 = 16.5%) conditions. Blood samples were taken before the exercise, following its cessation, and after 30 min of recovery. We found that TT increased dihydrosphingosine-1-phosphate (dhS1P) concentration in plasma (both HDL- and albuminbound) and blood cells, as well as the rate of dhS1P release from erythrocytes, regardless of oxygen availability. Plasma concentration of S1P was, however, reduced during the recovery phase, and this trend was augmented by hypoxia. On the other hand, GE in normoxia induced a selective increase in HDL-bound S1P. This effect disappeared when the exercise was performed in hypoxia, and it was associated with reduced S1P level in platelets and erythrocytes. We conclude that submaximal exercise elevates total plasma dhS1P concentration via increased availability of dihydrosphingosine resulting in enhanced dhS1P synthesis and release by blood cells. Maximal exercise, on the other hand, induces a selective increase in HDL-bound S1P, which is a consequence of mechanisms not related to blood cells. We also conclude that hypoxia reduces post-exercise plasma S1P concentration.

BackgroundThe clinical course of ischemic and hemorrhagic strokes can be influenced by the coagulation status of individual patients. The prior use of antiplatelet therapy (APT) such as acetylsalicylic acid (ASA) or P2Y12-antagonists has been inconsistently described as possibly increasing the risk of hemorrhagic transformation or expansion. Since clinical studies describing prior use of antiplatelet medication are overwhelmingly lacking specific functional tests, we aimed to implement testing in routine stroke care.MethodsWe used fluorescence-activated cell sorting (FACS) with antibodies against CD61 for thrombocyte identification and CD62p or platelet activation complex-1 (PAC-1) to determine platelet activation. Aggregometry and automated platelet functioning analyzer (PFA-200) were employed to test thrombocyte reactivity. FACS and aggregometry samples were stimulated in vitro with arachidonic acid (AA) and adenosine diphosphate (ADP) to measure increase in CD62p-/PAC-1-expression or aggregation, respectively.ResultsBetween February and July 2023, 20 blood samples (n = 11 ischemic strokes; n = 7 hemorrhagic strokes; n = 2 controls) were acquired and analyzed within 24 h of symptom onset. N = 11 patients had taken ASA, n = 8 patients no APT and n = 1 ASA+clopidogrel. ASA intake compared to no APT was associated with lower CD62p expression after stimulation with AA on FACS analysis (median 15.8% [interquartile range {IQR} 12.6–37.2%] vs. 40.1% [IQR 20.3–56.3%]; p = 0.020), lower platelet aggregation (9.0% [IQR 7.0–12.0%] vs. 88.5% [IQR 11.8–92.0%]; p = 0.015) and longer time to plug formation with PFA-200 (248.0 s [IQR 157.0–297] vs. 121.5 s [IQR 99.8–174.3]; p = 0.027). Significant correlations were noted between AA-induced CD62p expression and aggregometry analysis (n = 18; ρ = 0.714; p < 0.001) as well as a negative correlation between CD62p increase and PFA clot formation time (n = 18; ρ = −0.613; p = 0.007). Sensitivity for ASA intake was highest for PFA (81.8% for values ≥155.5 s). The combination of ASA + clopidogrel also affected ADP-induced CD62p and PAC-1 expression.ConclusionIn the clinical setting it is feasible to use differentiated platelet analytics to determine alterations caused by antiplatelet therapy. Among the tests under investigation, PFA-200 showed the highest sensitivity for the intake of ASA in stroke patients. FACS analysis on the other hand might be able to provide a more nuanced approach to altered platelet reactivity.

Thrombocytes play an essential role in hemostasis and thrombosis. Moreover, the controlled activation of thrombocytes is required in reproduction and fertility. The platelet-activating factor and the controlled activation of platelets have important roles in folliculogenesis, ovulation, placental development, implantation and embryo development. Activated platelets accumulate in the follicular vessels surrounding the follicle and, due to its released soluble molecules (factors, mediators, chemokines, cytokines, neurotransmitters), locally increase oocyte maturation and hormone secretion. Furthermore, activated platelets are involved in the pathogenesis of ovarian hyperstimulation syndrome (OHSS) and preeclampsia. Low-dose aspirin can prevent OHSS during ovulation induction, while intrauterine or intraovarian administration of platelet-rich plasma (PRP) increases the endometrium thickness and receptivity as well as oocyte maturation. Activated thrombocytes rapidly release the contents of intracellular granules and have multiple adhesion molecules and receptors on their surface. Considering the numerous homeostatic endocrine functions of thrombocytes, it is reasonable to suppose a platelet-associated regulatory system (PARS) in reproduction. Although we are far from a complete understanding of the regulatory processes, the results of PARS research and the therapeutic application of aspirin and PRP during in vitro fertilization are promising. [ABSTRACT FROM AUTHOR]

Examining tortoises’ blood cell parameters in natural populations could be useful for monitoring their health status. The current study examines the blood cell morphology of Eastern Hermann's tortoise in populations inhabiting three distinct locations in Serbia: Čermor, Gonjište, and Kunovica. We analyzed the number and morphometric parameters of different types of peripheral blood cells, including their length, width, and cell and nuclear size, and compared blood cell morphology across populations, sexes, and seasons (spring and summer). Our findings revealed significant variations in erythrocyte and lymphocyte morphometry among Eastern Hermann's tortoises from different populations and sexes, highlighting the influence of these factors on blood cell characteristics. Seasonal differences were observed in lymphocyte and thrombocyte counts, emphasizing the dynamic nature of hematological parameters in these tortoises. Additionally, alterations in erythrocyte cytoplasm were observed, suggesting potential pathological conditions. Establishing reference hematological intervals for healthy wild populations is crucial for monitoring health status, identifying early indicators of stress or disease, and guiding conservation efforts for Eastern Hermann's tortoises. Our results contribute to the general knowledge of the blood cell characteristics of Hermann's tortoise and provide insights into potential population-level differences in their physiology. [ABSTRACT FROM AUTHOR]

Background: Phenobarbital (PB) is used as a first‐line treatment for recurrent epileptic seizures in cats. While hematologic abnormalities are well‐known side effects of antiepileptic therapy with PB in humans and dogs, little is known about such alterations in cats. Objectives: The aim of this retrospective study was to investigate the prevalence and clinical relevance of cytopenia during PB treatment in cats. Methods: In this single‐center, retrospective clinical study, 69 cats—with suspected idiopathic epilepsy admitted to the Small Animal Clinic of the University of Veterinary Medicine in Vienna (VMU)—were included. A complete blood count for each patient was performed, and changes in hematocrit, leukocytes, neutrophils, and thrombocytes were documented and graded. Results: Fifty‐three out of 69 cats (76.8%) showed cytopenias with a reduction of at least one cell fraction during PB treatment. The most frequent change was neutropenia (60%), followed by leukopenia (49.3%), thrombocytopenia (24.1%), and anemia (20.3%). Most of the changes were mild or moderate; only one patient (1.5%) showed severe leukopenia and neutropenia, and one was a life‐threatening neutropenia (1.5%) with a serum PB concentration within or even below the therapeutic range. These patients did not present with clinical symptoms other than those related to epileptic episodes. Cats who received combination therapy showed lower hematocrits than those who received monotherapy. A tendency for leukocytes and neutrophils to decrease during PB treatment was also seen. Conclusions: Blood cytopenias may frequently occur in cats on chronic PB therapy, even when serum drug levels are within the therapeutic range. However, clinical signs are typically mild to moderate and rarely severe. [ABSTRACT FROM AUTHOR]

Patients with severe infection have an increased risk of cardiovascular events. A possible underlying mechanism is inflammation-induced platelet aggregation. We investigated whether hyperaggregation occurs during infection, and whether aspirin inhibits this. In this multicentre, open-label, randomised controlled trial, patients hospitalised due to acute infection were randomised to receive 10 days of aspirin treatment (80 mg 1dd or 40 mg 2dd) or no intervention (1:1:1 allocation). Measurements were performed during infection (T1; days 1–3), after intervention (T2; day 14) and without infection (T3; day > 90). The primary endpoint was platelet aggregation measured by the Platelet Function Analyzer® closure time (CT), and the secondary outcomes were serum and plasma thromboxane B2 (sTxB2 and pTxB2). Fifty-four patients (28 females) were included between January 2018 and December 2020. CT was 18% (95%CI 6;32) higher at T3 compared with T1 in the control group (n = 16), whereas sTxB2 and pTxB2 did not differ. Aspirin prolonged CT with 100% (95%CI 77; 127) from T1 to T2 in the intervention group (n = 38), while it increased with only 12% (95%CI 1;25) in controls. sTxB2 decreased with 95% (95%CI − 97; − 92) from T1 to T2, while it increased in the control group. pTxB2 was not affected compared with controls. Platelet aggregation is increased during severe infection, and this can be inhibited by aspirin. Optimisation of the treatment regimen may further diminish the persisting pTxB2 levels that point towards remaining platelet activity. This trial was registered on 13 April 2017 at EudraCT (2016-004303-32). [ABSTRACT FROM AUTHOR]

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To better characterize occurrence and extent of anticoagulant-associated pseudothrombocytopenia (PTCP) in the daily routine of a high-throughput clinical laboratory in order to draw conclusions on a more precise definition of this phenomenon.

Surgical-induced hemostasis is a critical step in the closure of incisions, which is frequently achieved via electrocauterization and subsequent tissue necrotization. The latter is associated with postoperative complications. Recent in vivo work suggested reactive species-producing gas plasma technology as a pro-homeostatic agent acting via platelet activation. However, it remained elusive how platelet activation is linked to lipid and protein oxidation and the reactive species compositions. A direct relation between the reactive species composition and platelet activation was revealed by assessing the production of several reactive species and by using antioxidants. In addition, platelet lipidome and proteome analysis identified significantly regulated key lipids in the platelet activation pathway, such as diacylglycerols and phosphatidylinositol as well as oxylipins like thromboxanes. Lipid oxidation products mainly derived from phosphatidylethanolamine and phosphatidylserine species were observed at modest levels. In addition, oxidative post-translational modifications were identified on key proteins of the hemostasis machinery. This study provides new insights into oxidation-induced platelet activation in general and suggests a potential role of those processes in gas plasma-mediated hemostasis in particular. [Display omitted] • Direct relation of gas plasma-derived reactive species and human platelet activation found. • Lipidomics and proteomics revealed key lipids and proteins regulated in gas plasma-activated platelets. • Lipid oxidation products and oxidative post-translational modifications identified via high-resolution mass spectrometry. [ABSTRACT FROM AUTHOR]

PURPOSE: The study aimed to determine a simple diagnostic test that could predict the risk of anastomotic leakage in early postoperative period. METHODS: A single-center, retrospective study was conducted. The electronic medical records of patients who underwent resection for rectal tumor between January 1, 2016, and December 31, 2021, in University Hospital Olomouc, were reviewed. The data included risk factors for leakage and laboratory parameters commonly obtained. RESULTS: The decrease in platelets was signifi cant as for the possibility of being a marker of anastomotic leakage; OR = 0.980 (p = 0.036). A decrease of 34 or higher predicts leakage with a sensitivity of 45 % (95 % CI: 23.1–68.5 %) and specifi city of 81.1 % (95 % CI: 75.2–86.1 %). Postoperative leukocyte blood level (OR = 1.134; p = 0.019) and leukocyte level on postoperative day 1 (OR = 1.184; p = 0.023) were signifi cant predictors for leakage. WBC values ≥ 8.8 predict leakage with a sensitivity of 70.0 % (95 % CI: 45.7–88.1 %) and specifi city of 55.3 % (95 % CI: 48.4–62.0 %). Hemoglobin blood level ≤ 79.5 predicts leakage with a sensitivity of 70.0 % (95 % CI: 45.7–88.1 %) and specifi city of 62.2 % (95 % CI: 55.5–68.7 %). CONCLUSION: Despite the fact that the specifi city and sensitivity of the followed parameters are low, they could serve as markers useful for early diagnosis or suspicion for leakage (Tab. 5, Fig. 3, Ref. 14). Text in PDF www.elis.sk. [ABSTRACT FROM AUTHOR]

Platelets or thrombocytes play an important role in thrombosis and maintaining hemostasis. Thrombocytes help in forming blood clots at the site of the wound. When the level of platelets decreases, uncontrolled bleeding occurs which can result in mortality. A decrease in the blood platelet level is known as thrombocytopenia which can be caused due to various reasons. A variety of treatment options are available for thrombocytopenia like platelet transfusion, splenectomy, platelet management with various types of corticosteroids, and recombinant interleukin-11 (rhIL-11). The use of rhIL-11 is approved by FDA for the treatment of thrombocytopenia. rhIL-11 is a recombinant cytokine that is administered to patients suffering from chemotherapy-induced thrombocytopenia as it enhances megakaryocytic proliferation which aids in platelet production. But this treatment has various side effects and is costly. Hence, there is a crucial need to identify cost-effective alternative strategies that present no side effects. The majority of the population in low-income countries requires a functional and cost-effective treatment for low thrombocyte count. Carica papaya is a tropical herbaceous plant that has been reported in recovering low platelet count during dengue virus infection. Even though multiple benefits of the Carica papaya leaf extract (CPLE) are popular, the active compound present in it, which mediates these benefits, remains to be identified. This review aims to highlight the different aspects of rhIL-11 and CPLE-induced platelet counts and their limitations and benefits in the treatment of thrombocytopenia. The literature related to the treatment of thrombocytopenia using rhIL-11 and CPLE from 1970 to 2022 was searched using PubMed and Google Scholar databases with the keywords Recombinant Interleukin-11, Papaya Leaf Extract, Thrombocytopenia, and Platelets. [ABSTRACT FROM AUTHOR]

Aim: Recurrent pregnancy loss (RPL) is known to be associated with increased thrombophilia and oxidative toxicity. However, the mechanism of thrombophilia apoptosis and oxidative toxicity is still unclear. In addition, the treatment of heparin induced regulator roles on intracellular free Ca2+ ([Ca2+]i) and cytosolic reactive oxygen species (cytROS) concentrations in several diseases. TRPM2 and TRPV1 channels are activated by different stimuli, including oxidative toxicity. The aim of this study was to investigate the effects of low molecular weight heparin (LMWH) via modulation of TRPM2 and TRPV1 on calcium signaling, oxidative toxicity, and apoptosis in the thrombocytes of RPL patients. Study Design: Thrombocyte and plasma samples collected from 10 patients with RPL and 10 healthy controls were used in the current study. Main Findings: The [Ca2+]i concentration, cytROS (DCFH‐DA), mitochondrial membrane potential (JC‐1), apoptosis, caspase‐3, and caspase‐9 levels were high in the plasma and thrombocytes of RPL patients, although they were diminished by the treatments of LMWH, TRPM2 (N‐(p‐amylcinnamoyl)anthranilic acid) and TRPV1 (capsazepine) channel blockers. Conclusions: The current study results suggest that the treatment of LMWH is useful against apoptotic cell death and oxidative toxicity in the thrombocytes of patients with RPL, which seem to be dependent on increased levels of [Ca2+]i concentration via the activation of TRPM2 and TRPV1. [ABSTRACT FROM AUTHOR]

Leucocytozoon parasites remain poorly investigated in comparison to other haemosporidians. The host cell inhabited by their blood stages (gametocytes) remains insufficiently known. This study aimed to determine the blood cells inhabited by Leucocytozoon gametocytes in different species of Passeriformes and to test if this feature has a phylogenetic importance. We microscopically analyzed blood films stained with Giemsa from six different bird species and individuals and used PCR-based methods for parasite lineage identification. The DNA sequences obtained were applied for phylogenetic analysis. Leucocytozoon parasite from the song thrush Turdus philomelos (cytochrome b lineage STUR1), the blackbird Turdus merula (undetermined lineage), the garden warbler Sylvia borin (unknown lineage) inhabited erythrocytes, a parasite from the blue tit Cyanistes caeruleus (PARUS4) infects lymphocytes, while in the wood warbler Phylloscopus sibilatrix (WW6) and the common chiffchaff Phylloscopus collybita (AFR205) they were found inhabiting thrombocytes. Parasites infecting thrombocytes were closely related, while the parasites infecting erythrocytes were placed in three different clades, and the one found in lymphocytes was placed in a separate clade. This shows that the determination of host cells inhabited by Leucocytozoon parasites can be phylogenetically important and should be considered in future species descriptions. Noteworthy, phylogenetic analysis might be used for the prediction of which host cells parasite lineages might inhabit. [ABSTRACT FROM AUTHOR]

Pegagan embun (Hydrocotyle sibthorpioides Lam.) has been studied as an immunostimulant, increasing macrophage cell activity and phagocytosis capacity. Based on that circumstance, the study aims to prove the immunostimulating effect by measuring the activity of Hydrocotyle sibthorpioides Lam. extract in the capsule for the complete blood profile of healthy volunteers. The number of volunteers used was twenty people, and the volunteers were divided into two groups. The first group was given a placebo capsule without Hydrocotyle sibthorpioides Lam. extract. The second group was given a capsule with Hydrocotyle sibthorpioides Lam. extract with a dose of 67 mg, which was taken once a day for three days. Blood sampling was obtained before and after taking the capsule preparation. Observation of the complete blood profile was conducted by investigating changes in blood parameters such as haemoglobin levels, number of erythrocytes, number of leukocytes, hematocrit values, number of thrombocytes and the percentage of leukocyte types (banded neutrophils, segmented neutrophils, eosinophils, basophils, monocytes, and lymphocytes). The second group given Hydrocotyle sibthorpioides Lam. extract showed a significant effect on the increase in haemoglobin levels, number of thrombocytes and hematocrit values (p<0.05). The percentage of leukocyte type values showed that lymphocytes increased significantly (p<0.05). In contrast, the segmented neutrophil increased but did not show a significant difference with the percentage of banded neutrophils, eosinophils, basophils and monocytes (p>0.05). There was a nonsignificant result in all parameters for the first group, which was administrated with a placebo capsule without Hydrocotyle sibthorpioides Lam. extract.v [ABSTRACT FROM AUTHOR]

Background: Beetroots are considered a vital source of nutrition and are usually incorporated into the daily diet to prevent different disease conditions. The therapeutic effect observed is due to the presence of active ingredients in the vegetables. The majority of our population, especially females, suffers from anemia due to malnutrition. The perseverance of this research was to explore the hematopoietic effects of lyophilized beetroot powder at different doses so they could be recommended as a nutritional supplement. Methodology: Albino rabbits weighing 1500-2000 gm of either gender were selected for the study and alienated into three sets. Set I was administered distilled water, whereas sets II and III were given lyophilized beetroot 500 mg/kg and 1000 mg/kg, correspondingly. For hematopoietic evaluation of blood, automated huma count plus was utilized. After adjusting according to their weights, lyophilized beetroot powder was suspended in distilled water and given at 500 mg/kg and 1000 mg/kg to rabbits. They were dosed once daily for two months. Results: The effects were verified before the dosing was scheduled and on the 30th day and 60th day of dosing. The outcomes presented a highly noteworthy increase (p

Background: Inflammation is important in the development of atherosclerosis. Research suggested sex-dependent differences for the value of inflammatory markers for risk stratification of stroke patients with internal carotid artery stenosis (ICAS). We investigated whether leukocytes and thrombocytes were associated with ≥50% ICAS in acute stroke and whether this was sex-dependent. Patients included in the Preventive Antibiotics in Stroke Study (PASS) were used. PASS is a randomized controlled trial that randomized between four days of preventive ceftriaxone intravenously or standard stroke care alone. It investigated whether ceftriaxone could improve functional outcome at three months after stroke. Methods: Patients included in PASS were evaluated for the predictive value of leukocytes and thrombocytes for ICAS. Ischemic stroke and TIA patients were selected out of PASS patients. Logistic regression analysis was performed adjusting for NIHSS and other covariates. Results: 2550 patients were included in PASS. 1413 of 2550 patients (55%) were evaluated in this sub study. Female patients showed a mean of 8.55 × 109/L for leukocytes and 259 × 109/L for thrombocytes. Men showed a mean of 8.29 × 109/L for leukocytes and 224 × 109/L for thrombocytes. Multivariate logistic regression analysis showed that leukocytes were independently associated with ICAS ≥ 50% in male patients (OR 1.094, p = 0.008), but not in female patients (OR 1.041, p = 0.360). Thrombocytes were not associated with ICAS. Conclusions: We conclude that blood leukocyte count independently predicts ICAS in men after acute stroke, but not in women. Clinical Trial unique identifier: ISRCTN66140176. [ABSTRACT FROM AUTHOR]

In our laboratory, we study thrombopoiesis and hemostasis using zebrafish as a model organism to unravel the mechanisms of differentiation and development of thrombocytes. We have shown in our earlier work that thrombocytes are functional equivalents of platelets and have transcriptional machinery similar to megakaryocytes. We recently found evidence that hox genes play a role in their development. We used piggyback gene knockdown and thrombocyte quantification assays to understand the influence of these ancient developmental regulators on thrombopoiesis. In this chapter, we describe methods used to discover these hox genes., (© 2025. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)

In humans, splenectomy is performed to treat many clinical disorders, including immune thrombocytopenia. However, the incidence of splenectomies for immune thrombocytopenia as a therapeutic has significantly declined over the past decade due to the availability of new therapies. Infection and sepsis as a result of splenectomies are well documented, but other long-term effects are not well characterized. Evidence suggests that persons who have had a prior splenectomy may be at an increased risk of vascular conditions. Also, elevated levels of cell-derived microparticles appear to contribute to an increased risk of thrombosis and cardiovascular disease. However, in vivo studies on the increased levels of microparticles following splenectomy are limited. In order to understand the effects of splenectomies, we developed a protocol for splenectomy in adult zebrafish. After anesthesia, the spleen was removed under a stereomicroscope after making an incision on the ventral side of the fish. The spleen was removed by pulling with forceps. The incision was closed by Vetbond tissue glue. Blood collected from both splenectomized zebrafish and those that underwent sham surgeries was immunolabeled with polyclonal antisera against αIIb, followed by flow cytometry. We observed elevated levels of thrombocytes and their microparticles in splenectomized zebrafish. Finally, by injecting αIIb antibody intravenously into zebrafish, we found the thrombocyte counts decreased, suggesting the fish developed immune thrombocytopenia like conditions, which were then reversed by splenectomy. In summary, the model developed here should be useful to study molecular changes due to splenectomy. Also, the zebrafish will be useful in modeling treatment of immune thrombocytopenia like conditions.

Simple Summary: Head and neck cancer (HNC) treatment poses several challenges in clinical practice, and treatment side effects can be debilitating due to the close proximity of important anatomical structures. Cancer recurrence post-treatment presents some of the most challenging HNC management issues. This prospective study identifies high-risk groups for recurrence of head and neck cancer, based on commonly accessible clinical parameters. In this study with 272 HNC patients, elevated pre- and post-treatment CRP levels, low BMI and advanced stage at admission indicate higher risk for recurrence of disease. Using these parameters, a risk model is proposed which may be useful for estimating the probability of cancer recurrence and allow the identification of high and low-risk patients. This prospective study identifies high-risk groups for recurrence of head and neck cancer by BMI and circulating inflammatory response markers. Head and neck cancer patients from three Swedish hospitals were included (n = 272). Leukocyte and thrombocyte counts, CRP levels, and BMI were measured pre-treatment and post-treatment. Associations between the four factors and treatment failure (residual tumor, loco-regional failure, general failure/distant metastasis) were assessed using a Cox proportional hazards model adjusted for sex, age at the initial visit, smoking status, cancer stage, and hemoglobin count. CRP level was the only significant single variable, with an average increase in risk of recurrence of 74% (p = 0.018) for every doubling. The predictive power of a combined model using all variables was highest during the initial months after treatment, with AUC under the ROC curve 0.75 at the 0–3 month timepoints. Patients with elevated pre- and post-treatment CRP levels are at higher risk for recurrence of disease. Male patients with low post-treatment BMI, advanced stage, and high CRP at any time post treatment are at high risk for recurrence. The combined model may be useful for stratifying post-treatment patients into low and high-risk groups, to enable more detailed follow-up or additional treatment regimens. [ABSTRACT FROM AUTHOR]

Background: Adult primary immune thrombocytopenia (ITP) is a rare bleeding disorder of unknown cause. Recent estimates of its incidence and trend over time were acquired for England. Method: The primary ITP population (using ICD 10 code D693 and excluding secondary ITP cases; positive predictive value: 82.6%) was sourced from NHS Digital inpatient and outpatient. Incidence rate (IR) for England and by age groups, sex, and regions were calculated and trends were assessed using average annual percent change (AAPC). Results: A total of 25 805 patients (mean age 59 years; females 57.8%) diagnosed between 2003 and 2014 was identified. IRs increased from 4.2/100 000 to 6.4/100 000 over this period (AAPC:4.3%). For all sex‐specific age groups, the IRs significantly increased over time, except 18–29 years males. The greatest increase was among females aged 30–39 (AAPC:8.7%). In contrast, among ≥70 years, ITP was more common in males (highest IR among ≥80 years males: 23.9/100 000). England's average annual IR was 6.1/100 000 for 2010–14. An estimated 2.5/100 000 (based on UKITP Registry data) was estimated to require 1st line treatment whereas 2.4/100 000 would have 1st and 2nd line treatments within 6 months from diagnosis. IRs for London and East Midlands were the highest (6.5/100 000). Conclusions: This study found a rising incidence of primary ITP, with sharp increases among young women and elderly men. These findings put in context the impact of ITP on patients' lives and the healthcare services in England, especially with 17%–50% who may develop chronic ITP and require long‐term care. [ABSTRACT FROM AUTHOR]

For almost a century, familial hypercholesterolemia (FH) has been considered a serious disease, causing atherosclerosis, cardiovascular disease, and ischemic stroke. Closely related to this is the widespread acceptance that its cause is greatly increased low-density-lipoprotein cholesterol (LDL-C). However, numerous observations and experiments in this field are in conflict with Bradford Hill's criteria for causality. For instance, those with FH demonstrate no association between LDL-C and the degree of atherosclerosis; coronary artery calcium (CAC) shows no or an inverse association with LDL-C, and on average, the life span of those with FH is about the same as the surrounding population. Furthermore, no controlled, randomized cholesterol-lowering trial restricted to those with FH has demonstrated a positive outcome. On the other hand, a number of studies suggest that increased thrombogenic factors—either procoagulant or those that lead to high platelet reactivity—may be the primary risk factors in FH. Those individuals who die prematurely have either higher lipoprotein (a) (Lp(a)), higher factor VIII and/or higher fibrinogen compared with those with a normal lifespan, whereas their LDL-C does not differ. Conclusions: Many observational and experimental studies have demonstrated that high LDL-C cannot be the cause of premature cardiovascular mortality among people with FH. The number who die early is also much smaller than expected. Apparently, some individuals with FH may have inherited other, more important risk factors than a high LDL-C. In accordance with this, our review has shown that increased coagulation factors are the commonest cause, but there may be other ones as well. [ABSTRACT FROM AUTHOR]

In mammalian hematopoiesis, megakaryocytes mature and become polyploid in the bone marrow before releasing platelets into circulation. In contrast, fish produce thrombocytes in kidney marrow, where young thrombocytes undergo maturation in circulation, akin to platelets. Despite morphological differences, our single-cell sequencing revealed significant gene expression similarities between fish thrombocytes and mammalian megakaryocytes, including Nfe2, which is crucial in platelet production. In addition to nfe2 expression, we found four nfe2- related genes, nfe2I1a, nfe2I1b, nfe2I2a, and nfe2I3, were expressed in mature thrombocytes. However, only nfe2, nfe2l2a, and nfe2l3 are expressed in young thrombocytes. Thus, we hypothesized that Nfe2-related factors may also be involved in thrombocyte production. To address this, we knocked down the four novel nfe2- related genes by the piggyback method and found both young and mature thrombocytes reduced when nfe2, nfe2l1a, and nfe2l3 were knocked down. They also exhibited greater gill bleeding and prolonged time to occlusion (TTO) compared to controls. In summary, our study shows Nfe2I1a and Nfe2l3 as novel transcription factors that are positive regulators influencing adult zebrafish thrombopoiesis. [ABSTRACT FROM AUTHOR]

Platelets are enucleated fragments of cells with a diversity of internal granules. They are responsible for functions related to hemostasis, coagulation, and inflammation. The activation of these processes depends on a cascade coordinated by cytokines, chemokines, and components of purinergic signaling, such as ATP, ADP, and adenosine. Platelets express distinct components of the purinergic system: P2X1, P2Y1, PY12, and P2Y14 receptors; and the ectonucleotidases NTPDase, NPP, and 5NTE (ecto-5′-nucleotidase). Except for P2Y14, which has not yet exhibited a known function, all other components relate to the biological processes mentioned before. Platelets are known to display specific responses to microorganisms, being capable of recognizing pathogen-associated molecular patterns (PAMPs), engulfing certain classes of viruses, and participating in NETosis. Platelet function dysregulation implicates various pathophysiological processes, including cardiovascular diseases (CVDs) and infections. In COVID-19 patients, platelets exhibit altered purinergic signaling and increased activation, contributing to inflammation. Excessive platelet activation can lead to complications from thrombosis, which can affect the circulation of vital organs. Therefore, controlling the activation is necessary to end the inflammatory process and restore homeostasis. Ectonucleotidases, capable of hydrolyzing ATP, ADP, and AMP, are of fundamental importance in activating platelets, promising pharmacological targets for clinical use as cardiovascular protective drugs. In this review, we revisit platelet biology, the purinergic receptors and ectonucleotidases on their surface, and their importance in platelet activity. Additionally, we describe methods for isolating platelets in humans and murine, as well as the main techniques for detecting the activity of ectonucleotidases in platelets. Considering the multitude of functions revealed by platelets and their potential use as potent bioreactors able to secrete and present molecules involved in the communication of the vasculature with the immune system, it is crucial to deeply understand platelet biology and purinergic signaling participation to contribute to the developing of therapeutic strategies in diseases of the cardiovascular, inflammatory, and immune systems. [ABSTRACT FROM AUTHOR]

Leucocytozoon parasites remain poorly investigated in comparison to other haemosporidians. The host cell inhabited by their blood stages (gametocytes) remains insufficiently known. This study aimed to determine the blood cells inhabited by Leucocytozoon gametocytes in different species of Passeriformes and to test if this feature has a phylogenetic importance. We microscopically analyzed blood films stained with Giemsa from six different bird species and individuals and used PCR-based methods for parasite lineage identification. The DNA sequences obtained were applied for phylogenetic analysis. Leucocytozoon parasite from the song thrush Turdus philomelos (cytochrome b lineage STUR1), the blackbird Turdus merula (undetermined lineage), the garden warbler Sylvia borin (unknown lineage) inhabited erythrocytes, a parasite from the blue tit Cyanistes caeruleus (PARUS4) infects lymphocytes, while in the wood warbler Phylloscopus sibilatrix (WW6) and the common chiffchaff Phylloscopus collybita (AFR205) they were found inhabiting thrombocytes. Parasites infecting thrombocytes were closely related, while the parasites infecting erythrocytes were placed in three different clades, and the one found in lymphocytes was placed in a separate clade. This shows that the determination of host cells inhabited by Leucocytozoon parasites can be phylogenetically important and should be considered in future species descriptions. Noteworthy, phylogenetic analysis might be used for the prediction of which host cells parasite lineages might inhabit.

Background. Complete blood count (CBC) is a simple and affordable diagnostic tool that is routinely used in therapeutic practice. At the same time, its diagnostic and prognostic potentials in terms of management of acute myocardial infarction (AMI) are currently limited. Based on a number of previous studies, we suggest that the analysis of platelet count and indices among AMI patients may have significant diagnostic and prognostic value, as well as dynamic changes in these parameters during the treatment course.Objectives. To evaluate the value of platelet indices and ratios in terms of their diagnostic and prognostic potential among patients with AMI at the time of hospitalization and on the 7th day of treatment.Materials and methods. The study involved 152 patients diagnosed with AMI (Group 1), 30 patients diagnosed with the chronic coronary syndrome (Group 2) and 24 healthy volunteers (Group 3). CBC was performed for all participants to determine all platelet indices. Also, anamnestic and clinical data were evaluated, as well as results of the coronary angiography. GRACE score was calculated.Results. The highest diagnostic value was shown by the WBC/MPV ratio (AUC 0,798; sensitivity 83,1 %; specificity 65,1 %) and PLT/L ratio (AUC 0,644; sensitivity 62,7 %; specificity 53,5 %), as opposed to traditionally used MPV (AUC 0,426; sensitivity 47,5 %; specificity 48,8 %) and PLT (AUC 0,484; sensitivity 60,8 %; specificity 58,1 %). We were unable to establish a relationship between CBC platelet counts at the time of hospitalization and the risk of complications according to the GRACE score. However, those changes according to CBC were obtained on the 7th day of treatment. In particular, the number of platelets was associated with the risk of hospital (r = 0,287; p = 0,016) and 6-month mortality (r = 0,260; p = 0,30), the duration of ischemia (r = 0,238; p = 0,016) and the number of affected vessels according to the results of angiography (r = 0,395; p = 0,002). Similarly, P-LCC correlated with the risk of hospital (r = 0,483; p = Conclusion. We found that combined ratios such as WBC/MPV and PLT/L had a higher diagnostic value compared to MPV, PLT and P-LCR. The prognostic potential of platelet indices was significantly higher on the 7th day of hospital stay. In particular, elevated levels of platelets, platelets, and P-LCR were correlated with a higher risk of hospital and 6-month mortality.

CD4+FoxP3+ regulatory T cells (CD4+ Tregs) are known to dampen inflammation following severe trauma. Platelets were shown to augment their posttraumatic activation in burn injury, but the exact mechanisms remain unclear. We hypothesized that platelet activation mechanisms via GPIIb/IIIa, fibrinogen, and PAR4 have an immunological effect and modulate CD4+ Treg activation early after trauma. Therefore, C57Bl/6 N mice were injected with tirofiban (GPIIb/IIIa inhibition), ancrod (fibrinogen splitting enzyme), or tcY-NH2 (selective PAR4 antagonist peptide) before inducing a third-degree burn injury of 25% of the total body surface area. Changes in coagulation, and local and systemic CD4+ Treg activity were assessed via rotational thromboelastometry (ROTEM®) and phospho-flow cytometry 1 h post intervention. The inhibition of GPIIb/IIIa and fibrinogen locally led to a higher basic activity of CD4+ Tregs compared to non-inhibited animals. In contrast, PAR4 disruption on platelets locally led to an increased posttraumatic activation of CD4+ Tregs. Fibrinogen led to complete elimination of coagulation, whereas GPIIb/IIIa or PAR4 inhibition did not. GPIIb/IIIa receptor and fibrinogen inhibition increase CD4+ Tregs activity independently of trauma. Both are crucial for thrombus formation. We suggest platelets trapped in thrombi are unable to interact with CD4+ Tregs but augment their activity when circulating freely. In contrast, PAR4 seems to reduce CD4+ Treg activation following trauma. In summary, GPIIb/IIIa-, PAR4-, and fibrinogen-dependent pathways in platelets modulate CD4+ Treg baseline activity, independently from their hemostatic functionality. PAR4-dependent pathways modulate the posttraumatic interplay of platelets and CD4+ Tregs. [ABSTRACT FROM AUTHOR]

The examination of a peripheral blood smear is mandatory in case of unexplained thrombocytopenia or thrombocytosis. First, the number of platelets should be estimated in order to confirm the platelet count determined by the haematology analyser, and to rule out causes of spuriously low or elevated platelet counts. Second, the size and morphological features of the platelets, which may provide information on the underlying cause of the low or enhanced platelet count, have to be assessed.

Schizophrenia is a disorder of strange and disordered thoughts, delusions, hallucinations, inappropriate influences, and disorders of psychosocial functioning. One of the management of schizophrenia therapy is the administration of atypical antipsychotic drugs, namely clozapine. Clozapine is an antagonist of serotonin (5-HT2) and dopamine type 2 (D2) receptors. However, the risk of using clozapine provides a risk of side effects in the form of metabolic syndromes such as impaired blood glucose regulation and disorders of blood elements such as leukocytes and platelets. This study aims to determine the effect of using clozapine on blood glucose, leukocyte, and platelet levels in schizophrenia patients at Banyumas General Hospital. This research method was carried out by cross-sectional study in outpatient schizophrenia at Banyumas General Hospital who received clozapine therapy and had met the inclusion and exclusion criteria, taken by consecutive sampling, then examined blood glucose levels, leukocyte counts, and platelet counts before and after giving clozapine therapy. Samples were taken on day 1 and day 10 of drug use. Paired t-test statistical analysis was used to see the effect of using clozapine on glucose, leucocyte, and platelet levels. In the T-test, it was found that there was a relationship between the use of clozapine on the patient's blood glucose levels, the use of clozapine did not have a significant effect on the increase in leukocyte levels and there was also a relationship between the use of clozapine and the patient's platelet levels. The results showed that the patient had an increase in blood glucose levels by a percentage (100%), the patient had leukopenia by a percentage (63.5%), the patient had thrombocytopenia by a percentage (75%), while the other patients had thrombocytosis. Patients with hyperglycemia, leucopenia, and thrombocytopenia were those who used clozapine> 12 months

In humans, splenectomy is performed to treat many clinical disorders, including immune thrombocytopenia. However, the incidence of splenectomies for immune thrombocytopenia as a therapeutic has significantly declined over the past decade due to the availability of new therapies. Infection and sepsis as a result of splenectomies are well documented, but other long-term effects are not well characterized. Evidence suggests that persons who have had a prior splenectomy may be at an increased risk of vascular conditions. Also, elevated levels of cell-derived microparticles appear to contribute to an increased risk of thrombosis and cardiovascular disease. However, in vivo studies on the increased levels of microparticles following splenectomy are limited. In order to understand the effects of splenectomies, we developed a protocol for splenectomy in adult zebrafish. After anesthesia, the spleen was removed under a stereomicroscope after making an incision on the ventral side of the fish. The spleen was removed by pulling with forceps. The incision was closed by Vetbond tissue glue. Blood collected from both splenectomized zebrafish and those that underwent sham surgeries was immunolabeled with polyclonal antisera against αIIb, followed by flow cytometry. We observed elevated levels of thrombocytes and their microparticles in splenectomized zebrafish. Finally, by injecting αIIb antibody intravenously into zebrafish, we found the thrombocyte counts decreased, suggesting the fish developed immune thrombocytopenia like conditions, which were then reversed by splenectomy. In summary, the model developed here should be useful to study molecular changes due to splenectomy. Also, the zebrafish will be useful in modeling treatment of immune thrombocytopenia like conditions. [ABSTRACT FROM AUTHOR]

Thrombocytes circulate in the blood of nonmammalian vertebrates and are involved in hemostasis; however, many detailed characteristics of thrombocytes remain unclear. Recently, we established an amphibian thrombocyte cell line. Here, we report the finding that thrombocytes produce integrin alpha IIb (CD41)‐positive extracellular vesicles (EVs), which include microRNAs (miRs). Flow cytometric analysis showed the expression of CD41+ and phosphatidylserine on the surface of EVs. Nanotracking analysis showed that these CD41+ EVs were approximately 100 nm in diameter. As CD41+ EVs were also observed from African clawed frogs, the production of CD41+ EVs might be common to amphibians. Microarray analysis showed that the CD41+ EVs contain many kinds of miRs. These CD41+ EVs were phagocytosed by endothelial cells and macrophages. qPCR analysis showed that many angiogenesis‐related genes were up‐regulated in CD41+ EV‐treated endothelial cells. Over‐expression of some miRs in the CD41+ EVs increased the proliferation of endothelial cells. These results indicated that thrombocytes produced CD41+ EVs, including miRs, that were received by endothelial cells to induce the expression of angiogenesis‐related genes. These results indicated that the CD41+ EVs produced from thrombocytes act as signaling molecules to repair damaged blood vessels. [ABSTRACT FROM AUTHOR]

Background & Aims: The evidence regarding the use of anticoagulant (AC) agents in portal vein thrombosis (PVT) is increasing and, most patients undergo chronic treatment with low molecular weight heparin (LMWH) or vitamin K antagonists (VKA). Nevertheless, there are no clear data about who should receive antithrombotic therapy, when to initiate it, how long and what dose should be used for this set of patients. The aim of the study was to assess the outcome of patients with cirrhosis and portal vein thrombosis who received AC therapy, in terms of thrombus regression, bleeding events and survival rates. Methods: This observational and retrospective study included 107 cirrhotic patients diagnosed with PVT in a single tertiary center between 2010-2019. 54 received low molecular weight heparin or vitamin K antagonist (AC treatment group) and 53 were untreated. All patients were periodically follow-up to assess the evolution of PVT (regression, progression, stable thrombus) and potential occurrence of bleeding events. Results: The regression of portal vein thrombosis was significantly higher in the AC treatment group (OR=2.430; 95% CI=1.11-6.167; p=0.026), more than 50% of on-treatment patients experiencing regression of the thrombus. However, bleeding events were significantly more frequent in the AC treatment group (18.5% vs. 7.5%) and the risk of bleeding was associated with thrombocytes less than 50x103/mm3 (OR=8.266; 95%CI: 2.310-39.211; p=0.002). Survival was better in the AC treatment group (68.4% vs 48.7% at 5 years and 92.7% vs 77.8% at 1 year, p=0.038) and was lower in patients that experienced bleeding events (37.22% survival at 5 years, mean time survival 44 months, p=0.008). Conclusions: In our cohort of cirrhotic patients with PVT more than 50% of patients receiving AC therapy presented regression of the thrombus; most of them obtained partial recanalization. The bleeding complication rate was higher than expected, reaching 18%. The overall mortality was lower in the treated group. [ABSTRACT FROM AUTHOR]

This comprehensive review examines the role of fish thrombocytes, cells considered functionally analogous to platelets in terms of coagulation, but which differ in their origin and morphology. Despite the evolutionary distance between teleosts and mammals, genomic studies reveal conserved patterns in blood coagulation, although there are exceptions such as the absence of factors belonging to the contact system. Beyond coagulation, fish thrombocytes have important immunological functions. These cells express both proinflammatory genes and genes involved in antigen presentation, suggesting a role in both innate and adaptive immune responses. Moreover, having demonstrated their phagocytic abilities, crucial in the fight against pathogenic microorganisms, underscores their multifaceted involvement in immunity. Finally, the need for further research on the functions of these cells is highlighted, in order to better understand their involvement in maintaining the health of aquaculture fish. The use of standardized and automated methods for the analysis of these activities is advocated, emphaiszing their potential to facilitate the early detection of stress or infection, thus minimizing the economic losses that these adverse situations can generate in the field of aquaculture. • Fish thrombocytes resemble platelets but differ in origin, suggesting conserved coagulation patterns throughout evolution. • Despite differences between teleosts and mammals, genomic studies reveal conserved coagulation mechanisms. • Fish thrombocytes express proinflammatory and antigen-presenting genes, implying roles in both innate and adaptive immunity. • The demonstrated phagocytic capacity of fish thrombocytes highlights their multifaceted involvement in immunity. [ABSTRACT FROM AUTHOR]

Platelets play roles in malignancy, wound healing, and immunity. Nevertheless, their significance in postoperative outcomes is not established. This is a retrospective cohort study of 100,795 patients undergoing cancer surgery in 2010 and 2014 in >500 hospitals. Patients were stratified into five groups based on preoperative platelet counts. Multivariable logistic regression was used to determine the risk of 30-day mortality, morbidities, readmission, and prolonged hospitalization using the mid-normal group as a reference. We adjusted for demographic variables, comorbidities, and operation complexity. In the 2014 cohort, multivariable analysis showed that mortality was higher in patients with thrombocytopenia (OR 1.49, 95% CI [1.23–1.81]), high-normal platelets (OR 1.29, [1.06–1.55]), and thrombocytosis (OR 1.78, [1.45–2.19]). Composite postoperative morbidity followed a similar trend with thrombocytopenia (OR 1.34, [1.25–1.43]), high-normal counts (OR 1.41, [1.33–1.49]), and thrombocytosis (OR 2.20, [2.05–2.36]). Concordantly, the risks of prolonged hospitalization and 30-day readmission followed the same pattern. These results were validated in a large colon cancer cohort from the 2010 database. In conclusion, platelet count is a prognostic indicator in cancer surgeries. This could be related to the role of platelets in wound healing and immunity on one hand, and propagating malignancy on the other.

Recent studies have indicated that medical options without splenectomy, such as rituximab (RTX) or thrombopoietin receptor agonists (TPO-RAs), can be effective to treat persistent or chronic primary immune thrombocytopenia (ITP). However, it remains to be determined which of these strategies should be the first choice after the first-line treatment for newly diagnosed ITP. We performed a systematic review and network meta-analysis to establish a clinically meaningful hierarchy of the efficacy and safety of medical treatments for persistent or chronic ITP in adults. Randomized controlled trials (RCTs) evaluating medical treatments were included. Reviewers independently extracted data and assessed the risk of bias. The main outcome was the overall response (platelet≥ 50 × 109/L); incidence of bleeding episodes, necessity of rescue treatments, and therapy-related adverse events including thrombosis were the secondary endpoints. A total of 12 randomized controlled trials (N= 1306) were included in this study. Our main finding was an improved overall response in TPO-RA arms (both Eltrombopag and Romiplostim) compared with that of RTX or placebo. There were no significant differences between Eltrombopag and Romiplostim. Moreover, clinically significant bleeding episodes were decreased in TPO-RA arm compared with placebo. Therapy-related adverse events showed similar profiles, and were tolerable in all treatment arms. In conclusion, TPO-RAs can be first choices for the treatment of persistent and chronic ITP, rather than RTX, as alternatives to splenectomy. Future head-to-head trials including TPO-RAs vs. RTX or Eltrombopag vs. Romiplostim are necessary to validate our study findings and determine the most suitable therapy for persistent/chronic ITP.

Thrombocytopenia is the most common haemostatic disorder in patients admitted to Intensive Care Units (ICUs). The mechanisms contributing to a decrease in the platelet count in critically ill patients are multifactorial, among which sepsis and trauma are the most frequent. A differential diagnosis of profound thrombocytopenia is crucial for effective treatment. A low platelet count is a strong independent predictor of morbidity and mortality because it is associated with life-threatening bleeding or thrombosis. This article aims to outline the definition and pathophysiology of thrombocytopenia and present a three-step algorithm of the clinical management of this haemostatic disorder.