Impact of 6-hydroxydopamine on agonist-induced human platelet functional parameters: An explanation for platelet impairment in Parkinson's disease.

Parkinson's disease (PD) is the second-most prevalent neurodegenerative disease worldwide, which worsens with advancing age. It is a common movement disorder and is often associated with several vascular diseases with decreased stroke frequency. Circulating platelets substantially regulate vascular complications, including stroke, and share striking similarities with PD neurons. Although structural alterations in platelets are well-documented in PD, their functional parameters remain unclear. This study aimed to investigate the functional abnormalities in platelets associated with PD by evaluating key functional aspects such as adhesion, activation, secretion, aggregation, and clot retraction. To achieve this, we treated human blood platelets with 6-hydroxydopamine or 6-OHDA, that selectively destroys dopaminergic neurons, thereby creating an in vitro experimental model that closely resembles the pathogenic environment in PD, and examine its impact on platelet functions. In our study, platelet adhesion was assessed and further evaluated by a microplate reader, activation and secretion by a flow cytometer, aggregation by aggregometer, and clot retraction by Sonoclot. Phase-contrast and confocal microscopic studies further verified the results from the above experiments. Our findings showed that 6-OHDA treatment significantly inhibited thrombin (a platelet agonist)-induced functions, including adhesion, activation, aggregation, secretion, and clot retraction in human-washed platelets. In summary, this research provides pioneering evidence that 6-OHDA induces abnormal platelet functions, shedding light on the previously unexplored processes by which 6-OHDA affects platelet activity.

Flow Cytometry and Platelets.

Clinical assessment of platelet activation by flow cytometry is useful in the characterization and diagnosis of platelet-specific disorders and as a measure of risk for thrombosis or bleeding. Platelets circulate in a resting, "unactivated" state, but when activated they undergo alterations in surface glycoprotein function and/or expression level, exposure of granule membrane proteins, and exposure of procoagulant phospholipids. Flow cytometry provides the means to detect these changes and, unlike other platelet tests, is appropriate for measuring platelet function in samples from patients with low platelet counts. The present review will focus on flow cytometric tests for platelet activation markers.

Anti-Platelet Activity of Sea Buckthorn Seeds and Its Relationship with Thermal Processing.

Sea buckthorn (Hippophae rhamnoides L.) is a tree or shrub with small, orange berries. Sea buckthorn seeds have shown many properties beneficial to human health, including antioxidant, anti-hypertensive, anti-hyperlipidemic, and retinoprotective activities. Seeds, as a component of food, are often exposed to high temperatures, which can increase or decrease their biological activity. In our previous study, we showed that both raw and roasted sea buckthorn seeds had significant antioxidant activity, which was measured in human plasma in vitro. In this paper, we evaluated the effect of extracts from raw and roasted sea buckthorn seeds on several parameters of hemostasis in vitro, including thrombus formation in full blood (measured by the Total Thrombus formation Analysis System-T-TAS), blood platelet activation (based on the exposition of P-selectin, the active form of GPIIb/IIIa on their surface and platelet-derived microparticles formation), aggregation (measured with impedance aggregometry), adhesion to fibrinogen and collagen, arachidonic acid metabolism in washed platelets stimulated by thrombin, and COX-1 activity. We also measured the levels of free 8-isoprostane in plasma and the total non-enzymatic antioxidant status of plasma. The extract from roasted seeds (50 µg/mL) significantly prolonged the time of occlusion measured by T-TAS-the AUC10 (area under the curve) value was decreased by approximately 18%. Both extracts decreased the exposition of the active form of GPIIb/IIIa on the surface of platelets activated with 10 µM ADP (by 38.4-62.2%) and 20 µM ADP (by 39.7-51.3%). Moreover, the extract from raw seeds decreased the exposition of P-selectin on the surface of platelets stimulated with 20 µM ADP (by 31.2-34.9%). The adhesion of thrombin-stimulated platelets to fibrinogen and collagen was inhibited only by the extract from roasted sea buckthorn seeds (by 20-30%). Moreover, the extract from raw seeds inhibited the level of TBARS (thiobarbituric acid-reactive substances, an indicator of enzymatic peroxidation of arachidonic acid) in washed platelets stimulated with thrombin; the activity of COX-1 was inhibited by both extracts, although the effect of the extract from raw seeds was stronger. These results indicate that sea buckthorn seeds have anti-platelet activity that is not decreased by thermal processing, but more research is needed to determine which exact chemical compounds and mechanisms are responsible for this phenomenon.

Exploring the relationship between blood platelet and other components utilizing count regression: A cross-sectional study in Bangladesh.

Background and Aims: Blood, vital for transporting nutrients and maintaining balance, comprises red blood cells, white blood cells, and platelets, each pivotal. Imbalances lead to issues-low red cells cause fatigue (anemia), high white cells hint at infection, low counts raise infection risks. Using trendy statistical approaches, investigating the complex link between platelet counts and numerous blood components. Our investigation, leveraging count regression approaches, revealed deep insights into the interaction between platelet counts and other important hematological markers. Methods: A cross-sectional study utilized data from 3120 individuals, including both male and female participants, who visited these hospitals between June 16, 2022 and December 17, 2022, to assess their blood samples through testing by using convenience non-parametric sampling framework. Platelet count was taken into account as a measure of outcome in this research. This specific study region was chosen for its easy accessibility, which helped the seamless execution of the data-gathering technique. Count regression, negative binomial regression, and quasi-Poisson regression techniques have been employed for examining relationship of the data sets. Results: Three different count regression models were utilized to assess the proper association between the response and the relevant covariates and we found negative binomial count regression model (Akaike information criterion = 76.55, Bayesian information criterion = 76.59, and deviance = 3.14) was providing comparatively better performance than others. Based on the chosen model we found white blood cell, erythrocyte sedimentation rate, and eosinophils are significant but neutrophil, monocyte, and lymphocyte are not significant. We have also gone through proper model adequacy checking for our selected model and we found enough evidence to justify our model. Conclusion: From the result, we found insightful remarks into the mechanisms involved in platelet production and regulation, which can aid in developing increased effective treatments and interventions to maintain optimal platelet levels and prevent health problems related to abnormal platelet counts.

Safety Results for Geographic Atrophy Associated with Age-Related Macular Degeneration Using Subretinal Cord Blood Platelet-Rich Plasma.

Purpose: To evaluate the safety of subretinal injection of cord blood platelet-rich plasma (CB-PRP) and its possible effect in eyes affected by geographic atrophy (GA) associated with dry age-related macular degeneration (d-AMD). Design: Interventional, open-label study started in January 2021 with follow-up at 12 months (the Si.Cord Study). This study was a single-center, nonrandomized, sequential-assigned clinical trial conducted in Rome, Italy, at Fondazione Policlinico Universitario Agostino Gemelli IRCCS (ClinicalTrials.gov NCT04636853). Participants: Thirteen patients (26 eyes) with bilateral d-AMD-related GA were enrolled. One eye from each patient (with more advanced GA) underwent CB-PRP treatment, and the fellow eye was considered the control. All patients participated in follow-up at 12 months. Intervention: All 13 eyes received 23-gauge (G) vitrectomy and subretinal injection of CB-PRP using a 41-gauge needle. Main Outcomes and Measures: Best-corrected visual acuity (BCVA) with ETDRS letters, central macular thickness using OCT, and atrophic area measured on en face OCT images were assessed at baseline, 1, 3, 6, and 12 months. Results: The BCVA in the treated group was 34.46 ± 20.8 ETDRS at baseline, 40.84 ± 20.52 at 1 month, 40.07 ± 20.34 at 3 months, 39.38 ± 19.84 at 6 months, and 35.84 ± 18.38 at 12 months. In the untreated group, the BCVA was 53 ± 21.1 ETDRS letters at baseline, 51.54 ± 20.99 at 1 month, 46.62 ± 19.47 at 3 months, 46.85 ± 18.58 at 6 months, and 43.92 ± 17.97 at 12 months (2-way analysis of variance: interaction of treatment by eye or time, P = 0.084). Central macular thickness did not show a significant intereye difference at 12 months (P = 0.97). The atrophic geographic areas tended to increase in both treated and fellow eyes at 12 months (P < 0.0001). No inflammatory reaction, endophthalmitis, retinal detachment, uveitis, or other complications due to the subretinal injection of CB-PRP were observed during the follow-up. Conclusions: Subretinal injection of CB-PRP could be safely used for d-AMD in its GA form. Despite its safety, a larger cohort of patients, and probably a new way of administration, will be needed to understand whether the CB-PRP could have a role in the GA treatment. Financial Disclosures: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

New Findings Regarding the Effects of Selected Blue Food Colorants (Genipin, Patent Blue V, and Brilliant Blue FCF) on the Hemostatic Properties of Blood Components In Vitro.

Natural and synthetic colorants present in food can modulate hemostasis, which includes the coagulation process and blood platelet activation. Some colorants have cardioprotective activity as well. However, the effect of genipin (a natural blue colorant) and synthetic blue colorants (including patent blue V and brilliant blue FCF) on hemostasis is not clear. In this study, we aimed to investigate the effects of three blue colorants-genipin, patent blue V, and brilliant blue FCF-on selected parameters of hemostasis in vitro. The anti- or pro-coagulant potential was assessed in human plasma by measuring the following coagulation times: thrombin time (TT), prothrombin time (PT), and activated partial thromboplastin time (APTT). Moreover, we used the Total Thrombus formation Analysis System (T-TAS, PL-chip) to evaluate the anti-platelet potential of the colorants in whole blood. We also measured their effect on the adhesion of washed blood platelets to fibrinogen and collagen. Lastly, the cytotoxicity of the colorants against blood platelets was assessed based on the activity of extracellular lactate dehydrogenase (LDH). We observed that genipin (at all concentrations (1-200 µM)) did not have a significant effect on the coagulation times (PT, APTT, and TT). However, genipin at the highest concentration (200 µM) and patent blue V at the concentrations of 1 and 10 µM significantly prolonged the time of occlusion measured using the T-TAS, which demonstrated their anti-platelet activity. We also observed that genipin decreased the adhesion of platelets to fibrinogen and collagen. Only patent blue V and brilliant blue FCF significantly shortened the APTT (at the concentration of 10 µM) and TT (at concentrations of 1 and 10 µM), demonstrating pro-coagulant activity. These synthetic blue colorants also modulated the process of human blood platelet adhesion, stimulating the adhesion to fibrinogen and inhibiting the adhesion to collagen. The results demonstrate that genipin is not toxic. In addition, because of its ability to reduce blood platelet activation, genipin holds promise as a novel and valuable agent that improves the health of the cardiovascular system and reduces the risk of cardiovascular diseases. However, the mechanism of its anti-platelet activity remains unclear and requires further studies. Its in vivo activity and interaction with various anti-coagulant and anti-thrombotic drugs, including aspirin and its derivatives, should be examined as well.

Psychometrics of patient-reported outcomes measurement information system in von Willebrand disease, inherited platelet function disorders, and rare bleeding disorders.

Background: Patient-reported outcomes measurement information system (PROMIS) measures can be used to measure patient-reported outcomes. PROMIS measures, including computer adaptive tests (CATs) and short forms, have demonstrated the ability to adequately assess outcomes in patients with hemophilia. It is, however, unclear if PROMIS measures are suitable for patients with von Willebrand disease (VWD), inherited platelet function disorders (IPFDs), and rare bleeding disorders (RBDs). Objectives: To evaluate the feasibility, measurement properties, and relevance of PROMIS measures in adults with VWD, IPFDs, and RBDs. Methods: In this cross-sectional multicenter study, adults with VWD, IPFDs, and RBDs completed 9 PROMIS measures and the Short Form-36 version 2 (SF-36v2) electronically. Feasibility was determined by the number of completed items and floor/ceiling effects. Measurement properties included construct validity based on a multitrait-multimethod analysis and reliability using the reliability coefficient and greatest lower bound. Relevance was evaluated based on comparison with the Dutch general population. Results: In total, 111 patients (median age, 57 years [IQR, 44-67]; 60% VWD, 16% IPFD, 24% RBD) participated. Mean number of items answered varied from 5.3 to 8.7 (range, 4-12) per PROMIS CAT in patients with VWD. Construct validity was supported for all CATs and all instruments had a good reliability (≥0.70). The PROMIS measures had less ceiling effects than the SF-36v2. Conclusion: The PROMIS measures are a feasible, valid, and reliable alternative for the SF-36v2 in patients with primarily nonsevere forms of VWD. The relevance of the selected measures was limited. Additional research is necessary to evaluate the PROMIS measures in adults with IPFDs and RBDs.

Utility of thromboelastography with platelet mapping for monitoring platelet transfusion in qualitative platelet disorders.

BACKGROUND: Patients with pathogenic variants in RASGRP2 (inherited platelet disorder (IPD)-18) exhibit normal platelet counts but impaired platelet aggregation and αIIbß3 activation. Moderate-to-severe bleeding episodes require patients to be transfused with platelets and/or pro-hemostatic agents. We recently demonstrated that hemostatic efficacy of transfused platelets is limited by dysfunctional endogenous platelets in a mouse model of IPD-18 (Rasgrp2-/- mice), as dysfunctional platelets were recruited to the forming hemostatic plug but did not participate in clot contraction. Thus, higher amounts of transfused platelets were required to outcompete these dysfunctional cells and to reverse bleeding. OBJECTIVE: We here studied the usefulness of thromboelastography with platelet mapping (TEG-PM) for ex vivo monitoring of the hemostatic potential in Rasgrp2-/- mice transfused with various amounts of wild-type (WT) platelets. METHODS: Whole blood (WB) samples from WT and Rasgrp2-/- mice were tested in TEG-PM and parameters for clot formation and contraction (K time, α-angle, maximum amplitude [MA]) were measured. RESULTS: Rasgrp2-/- WB samples did not contract in TEG-PM, consistent with a critical role of this protein in αIIbß3 activation. Addition of WT platelets improved TEG parameters in a ratio-dependent manner, consistent with our recent in vivo studies showing impaired hemostasis at a 5:1, but not at a 2:1 ratio of mutant to WT platelets. K and α values were identified as better predictors of transfusion efficacy than MA, the most platelet-dependent TEG parameter. CONCLUSION: This proof-of-concept study supports the use of TEG-PM to monitor platelet transfusion ratios and hemostatic potential in IPD-18 and potentially other platelet disorders.

CORRELATION OF NEUTROPHIL-LYMPHOCYTE RATIO (NLR) AND PLATELET-LYMPHOCYTE RATIO (PLR) WITH COMPLICATIONS AND POSTOPERATIVE SURVIVAL IN SURGERY FOR BONE METASTASIS OF THE APPENDICULAR SKELETON / CORRELAÇÃO DO NEUTROPHIL-LYMPHOCYTE RATIO (NLR) E PLATELET-LYMPHOCYTE RATIO (PLR) COM COMPLICAÇÕES E SOBREVIDA PÓS-OPERATÓRIAS NA CIRURGIA PARA METÁSTASE ÓSSEA DO ESQUELETO APENDICULAR

Introduction: Bone metastasis is the most common malignant neoplasm of the skeleton, and surgical decision-making depends on multiple factors, including postoperative complications and life expectancy. The identification of new prognostic factors can assist in decision making. Objective: In long bones metastases, to analyze the incidence of complications and postoperative survival up to 1 year, correlating them with NLR and PLR. Method: Review of 160 medical records of patients who underwent surgery for bone metastasis in the appendicular skeleton. In addition to epidemiological characteristics, NLR and PLR values were determined, correlating them with survival and complications. Result: Women represented 64.5% with a primary breast tumor in 62.6%; the proximal femur was the most affected; median survival was 13.2 months and in 1 year 34.7%. Tumor resection with endoprosthesis was more common. The post-surgical complication rate was 10% and the average time for post-operative complications to occur was 27.9 days (0-140). An association between the neutrophil variable and postoperative complications was found (p=0.04). For every 100 more units of neutrophils there was a 1% increase in the chances of post-surgical complications. Mean NLR and PLR values were, respectively, 5.3 (0.2-30.7) and 199.7 (32.1-676.7). Patients with NLR NLR ≥ 2 (p<0,001) showed a decrease in survival from 92,3% to 62,5% at the 3rd month, and from 61,5% to 31,3% at 1 year. Those with PLR ≥209 (p<0.001) showed a decrease in survival from 69% to 59.3% at the 3rd month, and from 40.2% to 25.9% at 1 year. Conclusion: There was no positive association between NLR and PLR with postoperative complications, but strongly yes with survival from the 3rd month after surgery.

Introdução: Metástase óssea é a neoplasia maligna mais comum do esqueleto, e a tomada de decisão cirúrgica depende de múltiplos fatores, incluindo as complicações pós-operatórias e a expectativa de vida. A identificação de novos fatores prognósticos pode auxiliar na tomada de decisão. Objetivo: Analisar em metástases de ossos longos, a incidência de complicações e sobrevida pós-operatórias até 1 ano correlacionando-as com NLR e PLR. Método: Revisão de 160 prontuários de operados por metástase óssea no esqueleto apendicular. Além de características epidemiológicas, foram determinados os valores de NLR e PLR correlacionando-os com sobrevida e complicações. Resultado: Mulheres representaram 64,5% com tumor primário na mama em 62,6%; o fêmur proximal foi o mais acometido; sobrevida média foi 13,2 meses e a de 1 ano 34,7%; ressecção tumoral com endoprótese foi mais comum. A taxa de complicação pós-cirúrgicas foi de 10% e o tempo médio para a ocorrência de complicações pós-operatórias foi de 27,9 dias (0-140). Foi encontrada associação da variável neutrófilos com a complicação pós-operatória (p=0,04). A cada 100 unidades a mais de neutrófilos houve aumento de 1% nas chances de complicações pós-cirúrgicas. Valores médios do NLR e PLR foram, respectivamente, 5,3 (0,2-30,7) e 199,7 (32,1-676,7).  Os pacientes com NLR ≥ 2 (p<0,001) apresentaram diminuição na sobrevida de 92,3% para 62,5% no 3° mês e de 61,5% para 31,3% em 1 ano. Aqueles com PLR ≥209 (p<0,001) apresentaram diminuição na sobrevida de 69% para 59,3% no 3° mês, e de 40,2% para 25,9% em 1 ano. Conclusão: Não foi verificada associação positiva entre o NLR e o PLR com complicações pós-operatórias, mas com sobrevida fortemente sim, a partir do 3° mês de pós-operatório.

CAN NEUTROPHIL-LYMPHOCYTE RATIO (NLR) AND PLATELET-LYMPHOCYTE RATIO (PLR) BE PROGNOSTIC INDICATORS FOR OPERATIVE COMPLICATIONS AND SURVIVAL IN BONE METASTASES? / NEUTROPHIL-LYMPHOCYTE RATIO (NLR) E PLATELET-LYMPHOCYTE RATIO (PLR) PODEM SER INDICADORES DE PROGNÓSTICO PARA COMPLICAÇÕES OPERATÓRIAS E SOBREVIDA EM METÁSTASES ÓSSEAS?

Introduction: In general, inflammation stimulates the production and release of neutrophils and, at the same time, decreases the production of lymphocytes. Lymphopenia reflects that cell-mediated immunity is impaired, while neutrophilia represents a response to systemic inflammation in these cancers. Objective: To review the incidence of complications and postoperative survival rates in patients with bone metastases in long bones, correlating them with markers NLR and PLR. Method: Narrative review carried out collecting information published on virtual platforms in Portuguese and English, initially carried out by searching for descriptors related to the topic, which were: "lower extremity, surgery, metastasis, epidemiology, postoperative complications, neutrophils, lymphocytes, platelets". The extension incorporated AND or OR, by title and/or summary, and full reading of the texts most related to the topic. Result: 21 articles were included. Conclusion: The higher both the NLR and PLR are associated with lower survival in patients with bone metastases when undergoing surgical treatment, especially after 3 months postoperatively. However, there is still no confirmation that they signal any outcome, favorable or not, in relation to postoperative complications.

Introdução : De um modo geral, a inflamação estimula a produção e liberação de neutrófilos e, ao mesmo tempo, diminui a produção de linfócitos. A linfopenia reflete que a imunidade mediada pelas células é prejudicada, enquanto a neutrofilia representa resposta à inflamação sistêmica nesses cânceres. Objetivo : Revisar nos pacientes com metástase óssea em ossos ao longo da incidência de complicações e taxas de sobrevida pós-operatória correlacionando-as com os marcadores NLR e PLR. Método : Revisão narrativa feita colhendo informações publicadas em plataformas virtuais em português e inglês inicialmente realizada por busca dos descritores relacionados ao tema que foram: "extremidade inferior, cirurgia, metástase, epidemiologia, complicações pós-operatórias, neutrófilos, linfócitos, plaquetas" e seus equivalentes em inglês " extremidade inferior, cirurgia, metástase, epidemiologia, sobrevivência, complicações, neutrófilos, linfócitos, plaquetas sanguíneas ". A extensão incorporou AND ou OR, pelo título e/ou resumo, e leitura na íntegra dos textos mais relacionados ao tema.  Resultado : Foram incluídos 21 artigos. Conclusão : Quanto maiores, tanto o NLR quanto o PLR estão associados à menor sobrevida em pacientes com MO quando submetidos ao tratamento cirúrgico, especialmente após 3 meses de pós-operatório. Contudo, ainda não há confirmação de que eles sinalizam algum estágio, positivo ou não, em relação às complicações pós-operatórias.

Investigating the role of rotenone on human blood platelets: Molecular insights into abnormal platelet functions in Parkinson's disease.

Parkinson's disease (PD) is a predominant neuromotor disorder characterized by the selective death of dopaminergic neurons in the midbrain. The majority of PD cases are sporadic or idiopathic, with environmental toxins and pollutants potentially contributing to its development or exacerbation. However, clinical PD patients are often associated with a reduced stroke frequency, where circulating blood platelets are indispensable. Although platelet structural impairment is evident in PD, the platelet functional alterations and their underlying molecular mechanisms are still obscure. Therefore, we investigated rotenone (ROT), an environmental neurotoxin that selectively destroys dopaminergic neurons mimicking PD, on human blood platelets to explore its impact on platelet functions, thus replicating PD conditions in vitro. Our study deciphered that ROT decreased thrombin-induced platelet functions, including adhesion, activation, secretion, and aggregation in human blood platelets. As ROT is primarily responsible for generating intracellular reactive oxygen species (ROS), and ROS is a key player regulating the platelet functional parameters, we went on to check the effect of ROT on platelet ROS production. In our investigation, it became evident that ROT treatment resulted in the stimulation of ROS production in human blood platelets. Additionally, we discovered that ROT induced ROS production by augmenting Ca2+ mobilization from inositol 1,4,5-trisphosphate receptor. Apart from this, the treatment of ROT triggers protein kinase C associated NADPH oxidase-mediated ROS production in platelets. In summary, this research, for the first time, highlights ROT-induced abnormal platelet functions and may provide a mechanistic insight into the altered platelet activities observed in PD patients.

Should HLA and HPA-matched platelet transfusions for patients with Glanzmann Thrombasthenia or Bernard-Soulier syndrome be standardized care? A Dutch survey and recommendations.

BACKGROUND: Glanzmann thrombasthenia (GT) and Bernard-Soulier syndrome (BSS) patients require frequent platelet transfusions and hence have an increased risk for alloimmunization against donor Human Leukocyte Antigens (HLA) when no HLA-matching is performed. Knowing that Human Platelet Antigens (HPA) are located on the platelet glycoproteins that can be absent in these patients, preventive HPA-matching may also be considered. Uniform recommendations on this topic lack in transfusion guidelines making standard practice unclear, therefore, we aimed to provide a framework for matched platelet transfusions. STUDY DESIGN AND METHODS: We conducted a targeted literature search and a national survey of Dutch (pediatric) hematologists from July to September 2021. RESULTS: We found 20 articles describing platelet transfusion policies in 483 GT-patients and 29 BSS-patients, both adults and children. Twenty surveys were returned for full analysis. All responders treated patients with platelet disorders, including GT (n = 36 reported) and BSS (n = 29 reported). Of respondents, 75% estimated the risk of antibody formation as "likely" for HLA and 65% for HPA. Formation of HLA antibodies was reported in 5 GT and in 5 BSS-patients, including one child. Fifteen respondents gave preventive HLA-matched platelets in elective setting (75%). Three respondents additionally matched for HPA in GT-patients (15%). Main argument for matched platelet transfusions was preventing alloimmunization to safeguard the effectivity of 'random' donor-platelets in acute settings. CONCLUSION: Elective HLA-matching for GT and BSS-patients is already conducted by most Dutch (pediatric) hematologists. HPA-matching is mainly applied when HPA-antibodies are formed. Based on the current literature and the survey, recommendations are proposed.

Use of crushed tranexamic acid tablets in water for paediatric patients with bleeding disorders.

BACKGROUND: Ε-Aminocaproic acid oral solution (EACA OS) is the only commercially available antifibrinolytic for patients who cannot swallow tablets. Insurance denials and high costs remain barriers to its use. OBJECTIVES: To determine the safety and efficacy of crushed tranexamic acid tablets in water (cTXAw) for children with bleeding disorders. METHODS: We retrospectively reviewed records of children (<10 years) with bleeding disorders who received cTXAw or EACA OS from 1 December 2018, through 31 July 2022, at Mayo Clinic (Rochester, Minnesota). Bleeding outcomes were defined according to ISTH criteria. RESULTS: Thirty-two patients were included (median age, 3 years; male, n = 23). Diagnoses were VWD (n = 17), haemophilia (n = 5), FVII deficiency (n = 3), inherited platelet disorder (n = 4), ITP (n = 2), and combined FV and FVII deficiencies (n = 1). Thirty-two courses of cTXAw (monotherapy 24/32; mean duration 6 days) and fifteen courses of EACA (monotherapy 12/15; mean duration 5 days) were administered. No surgical procedures (n = 28) were complicated by bleeding. Of the 19 bleeding events, 16 had effective haemostasis, two had no reported outcome, and one had no response. cTXAw and EACA were equally effective in preventing and treating bleeding (p value > .1). No patients had adverse effects. Eight of 19 patients (42%) who were initially prescribed EACA OS did not receive it because of cost or insurance denial. The estimated average wholesale price of one treatment was $94 for cTXAw and $905 for EACA OS. CONCLUSIONS: CTXAw appears to be an effective, safe, and low-cost alternative option to EACA OS for young children with bleeding disorders.

ISTH bleeding assessment tool and platelet function analyzer in children with mild inherited platelet function disorders.

OBJECTIVES: To evaluate the diagnostic performance of platelet function analyzer (PFA) and The International Society on Thrombosis and Hemostasis bleeding-assessment-tool (ISTH-BAT) in detecting mild inherited platelet function disorders (IPFDs) in children with suspected bleeding disorders. METHODS: Prospective single-center diagnostic study including consecutive patients <18 years with suspected bleeding disorder and performing a standardized workup for platelet function defects including ISTH-BAT, PFA, platelet aggregation testing, blood smear-based immunofluorescence, and next-generation sequencing-based genetic screening for IPFDs. RESULTS: We studied 97 patients, of which 34 von Willebrand disease (VWD, 22 type-1, 11 type-2), 29 IPFDs (including delta-/alpha-storage pool disease, Glanzmann thrombasthenia, Hermansky-Pudlak syndrome) and 34 with no diagnosis. In a model combining PFA-adenosine diphosphate (ADP), PFA-epinephrine (EPI), and ISTH-BAT overall performance to diagnose IPFDs was low with area under the curves of 0.56 (95% CI 0.44, 0.69) compared with 0.84 (95% CI 0.76, 0.92) for VWD. Correlation of PFA-EPI/-ADP and ISTH-BAT was low with 0.25/0.39 Spearman's correlation coefficients. PFA were significantly prolonged in patients with VWD and Glanzmann thrombasthenia. ISTH-BAT-scores were only positive in severe bleeding disorders, but not in children with mild IPFDs or VWD. CONCLUSION: Neither ISTH-BAT nor PFA or the combination of both help diagnosing mild IPFDs in children. PFA is suited to exclude severe IPFDs or VWD and is in this regard superior to ISTH-BAT in children.

Potential for modulation of platelet function via adenosine receptors during inflammation.

Traditionally, platelets are known to play an important role in haemostasis and thrombosis; however, they serve also as important modulators of inflammation and immunity. Platelets secrete adhesion molecules and cytokines, interact with leukocytes and endothelium, and express toll-like receptors involved in a direct interaction with pathogens. Platelets express A2A and A2B subtypes of receptors for adenosine. The activation of these receptors leads to an increase in cAMP concentration in the cytoplasm, thereby resulting in inhibited secretion of pro-inflammatory mediators and reduced cell activation. Therefore, platelet adenosine receptors could be a potential target for inhibiting platelet activation and thus down-regulating inflammation or immunity. The biological effects of adenosine are short-lasting, because the compound is rapidly metabolized; hence, its lability has triggered efforts to synthesize new, longer-lasting adenosine analogues. In this article, we have reviewed the literature regarding the pharmacological potential of adenosine and other agonists of A2A and A2B receptors to affect platelet function during inflammation. LINKED ARTICLES: This article is part of a themed issue on Platelet purinergic receptor and non-thrombotic disease. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v181.4/issuetoc.

Immune Thrombocytopenic Purpura in an Adult Male: A Case Report.

Immune thrombocytopenic purpura (ITP) is an autoimmune disease characterized by immune-mediated destruction of platelets, resulting in a decreased blood platelet count (less than 100 x 109/L) in the absence of other known etiology of thrombocytopenia. ITP is uncommon in adult males. The signs and symptoms of ITP vary widely and are quite diverse. The degree of thrombocytopenia and bleeding are not always correlated. Timely diagnosis, intervention, and regular monitoring can easily prevent complications. We report a case of a 22-year-old male presented with gum bleeding along with purpura and ecchymosis over the upper limb, lower limb, trunk, and face.

Diversity of Megakaryocytes.

Megakaryocytes are commonly known as large, polyploid, bone marrow resident cells that contribute to hemostasis through the production of platelets. Soon after their discovery in the 19th century, megakaryocytes were described in tissue locations other than the bone marrow, specifically in the lungs and the blood circulation. However, the localization of megakaryocytes in the lungs and the contribution of lung megakaryocytes to the general platelet pool has only recently been appreciated. Moreover, the conception of megakaryocytes as uniform cells with the sole purpose of platelet production has been challenged. Here, we review the literature on megakaryocyte cell identity and location with a special focus on recent observations of megakaryocyte subpopulations identified by transcriptomic analyses.

Platelet to lymphocyte and neutrophil to lymphocyte ratio in the first trimester of pregnancy, are they useful for predicting spontaneous miscarriage? A case-control study.

Background: In 15% of all clinical pregnancies, a miscarriage can occur, but the exact cause of this phenomenon is not fully understood. However, it is believed that a faulty placenta, which triggers an inflammatory response in the mother's body, may be one of the causes. Medical literature has increasingly focused on 2 indicators of inflammation, the platelet-lymphocyte ratio (PLR) and neutrophil-lymphocyte ratio (NLR). Despite this, there has yet to be a study conducted that examines the rates of PLR and NLR in cases of miscarriage. Objective: This study aims to determine whether there is an increase in complete blood count inflammatory parameters such as NLR and PLR in women who experience miscarriages. Materials and Methods: This retrospective case-control study was conducted from March 2021 to March 2022, across 3 academic hospitals in Tehran, Iran. A total of 240 participants were enrolled comprising individuals with either miscarriages or normal pregnancies (n = 120/each). Data were collected from the medical records of participants aged between 18-42 yr old, with gestational age ranging from 6-13 wk. The demographic information, including age, body mass index, parity, history of abortion, number of abortions, number of living children, hematocrit and hemoglobin levels, platelet distribution width (PDW), PLR, NLR, mean platelet volume, and platelet were extracted from their records. The gestational age was also recorded. Results: A total of 240 participants were recruited for the study. PDW, NLR, PLR, and lymphocyte values were higher in the miscarriage group compared to the healthy normal pregnant women (p < 0.001). Mean platelet volumes were found to be lower in the miscarriage group compared to the healthy normal pregnant women (p < 0.001). Conclusion: Although, no statistically significant difference was observed in the hemoglobin, hematocrit, platelets, and neutrophils in these 2 groups of pregnant women. The higher inflammatory markers including PDW, NLR, and PLR could potentially aid in the speculation of defective placentation as a contributing factor to the development of miscarriage. Measurement of these markers may be useful to predict pregnancy leading to miscarriage.

Multicolor flow cytometry in clinical samples for platelet signaling assessment.

Background: Availability of multichannel cytometers and specific commercial antibodies makes flow cytometry a new option to simultaneously assess multiple intracellular platelet signaling pathways for clinical purposes, in small volume of blood or low platelet count. Objectives: To describe a multicolor flow cytometry with fluorescent barcoding technique for screening signaling pathways downstream membrane receptors of major platelet agonists (adenosine diphosphate, thrombin, thromboxane, and collagen). Methods: By comparison with immunoblotting, we first selected the target phosphoproteins, AKT, P38MAPK, LIMK, and SPL76; the times of stimulation; and phosphoflow barcoding conditions. We then performed a clinical study on whole blood of patients without evidence of blood platelet disorder on standard biological screening, consulting for trivial or occasionally provoked bleeds without familial antecedent (bleeding of unknown origin, n = 23) or type-1 von Willebrand disease (n = 9). In addition, we included a small group of patients with definite platelet disorders (Glanzmann thrombasthenia, δ-storage pool deficiency, and immune glycoprotein VI-related disease with granule secretion defect). Results: The range, kinetics, and distribution of fluorescence intensity were established for each agonist-target protein combination. Principal component analysis indicates a correlation in response to a target phosphoprotein (AKT and P38MAPK) to different agonists but no correlation in the response of different target phosphoproteins to the same agonist. The heterogeneity of individual responses in the whole population displayed was analyzed using clustering algorithm. Patients with platelet storage pool deficiency were positioned as lowest responders on the heatmap. Conclusion: In complement of functional tests, this study introduces a new approach for rapid platelet signaling profiling in clinical practice.

Innovative i-PRF semisurgical method for gingival augmentation and root coverage in thin periodontal phenotypes: a preliminary study.

OBJECTIVES: The aim of the study was to evaluate the effect of injectable platelet-rich fibrin (i-PRF) on gingival thickness and gingival recession in individuals with thin periodontal phenotypes. METHOD AND MATERIALS: In this prospective study, i-PRF was applied via a semisurgical method to augment 53 tooth regions with thin periodontal phenotypes. In order to ensure that sufficient blood clot formed on the side of the gingiva facing the bone and that i-PRF reached the area, a minimal incision was made with the help of a scalpel in the apical region of the relevant region, and the periosteum was elevated with a microsurgical instrument. To ensure sustained exposure to angiogenetic growth factors and enhance the histoconductive properties, i-PRF injection was applied to the relevant areas in four sessions at 10-day intervals. RESULTS: An increase in gingival thickness was achieved in 92.5% of the areas treated with i-PRF, and the desired gingival thickness (0.8 mm) was achieved in 44.9% of these areas. In addition, significant reductions in the amount of recession were observed in 83.3% of the 12 gingival recession areas (P = .005). Moreover, complete coverage was achieved in 60% of these regions. CONCLUSION: With the new i-PRF semisurgical method, it was shown that gingival thickness can be increased in tooth regions with thin gingiva, and that areas of gingival recession can be covered. Further comprehensive studies are needed to fully understand the role of i-PRF in enhancing angiogenesis and the histoconductive properties of this fully autogenous blood concentrate.