-
1.
An epitope-based approach of HLA-matched platelets for transfusion: a noninferiority crossover randomized trial.
Marsh, JC, Stanworth, SJ, Pankhurst, LA, Kallon, D, Gilbertson, AZ, Pigden, C, Deary, AJ, Mora, AS, Brown, J, Laing, ES, et al
Blood. 2021;(3):310-322
-
-
Free full text
-
Abstract
Platelet transfusion refractoriness results in adverse outcomes and increased health care costs. Managing refractoriness resulting from HLA alloimmunization necessitates the use of HLA antigen-matched platelets but requires a large platelet donor pool and does not guarantee full matching. We report the first randomized, double-blind, noninferiority, crossover trial comparing HLA epitope-matched (HEM) platelets with HLA standard antigen-matched (HSM) platelet transfusions. Alloimmunized, platelet-refractory, thrombocytopenic patients with aplastic anemia, myelodysplastic syndrome, or acute myeloid leukemia were eligible. HEM platelets were selected using HLAMatchMaker epitope (specifically eplet) matching. Patients received up to 8 prophylactic HEM and HSM transfusions provided in random order. The primary outcome was 1-hour posttransfusion platelet count increment (PCI). Forty-nine patients were randomized at 14 UK hospitals. For intention to treat, numbers of evaluable transfusions were 107 and 112 for HEM and HSM methods, respectively. Unadjusted mean PCIs for HEM and HSM methods were 23.9 (standard deviation [SD], 15) and 23.5 (SD, 14.1), respectively (adjusted mean difference, -0.1; 95% confidence interval [CI], -2.9 to 2.8). Because the lower limit of the 95% CI was not greater than the predefined noninferiority limit, the HEM approach was declared noninferior to the HSM approach. There were no differences in secondary outcomes of platelet counts, transfusion requirements, and bleeding events. Adequate 1-hour PCI was more frequently observed, with a mean number of 3.2 epitope mismatches, compared with 5.5 epitope mismatches for inadequate 1-hour increments. For every additional epitope mismatch, the likelihood of an adequate PCI decreased by 15%. Epitope-matched platelets should be considered to support HLA alloimmunized patients. This trial was registered at www.isrctn.com as #ISRCTN23996532.
-
2.
Inhaled nitric oxide to control platelet hyper-reactivity in patients with acute submassive pulmonary embolism.
Kline, JA, Puskarich, MA, Pike, JW, Zagorski, J, Alves, NJ
Nitric oxide : biology and chemistry. 2020;:20-28
-
-
Free full text
-
Abstract
BACKGROUND We test if inhaled nitric oxide (NO) attenuates platelet functional and metabolic hyper-reactivity in subjects with submassive pulmonary embolism (PE). METHODS Participants with PE were randomized to either 50 ppm NO + O2 or O2 only for 24 h with blood sampling at enrollment and after treatment; results were compared with healthy controls. Platelet metabolic activity was assessed by oxygen consumption (basal and uncoupled) and reactivity was assessed with agonist-stimulated thromboelastography (TEG) and fluorometric measurement of agonist-stimulated cytosolic [Ca++] without and with pharmacological soluble guanylate (sGC) modulation. RESULTS Participants (N = 38 per group) were well-matched at enrollment for PE severity, comorbidities as well as TEG parameters and platelet O2 consumption. NO treatment doubled the mean plasma [NO3-] (P < 0.001) indicating successful delivery, but placebo treatment produced no change. After 24 h, neither TEG nor O2 consumption parameters differed significantly between treatment groups. Platelet cytosolic [Ca++] was elevated with PE versus controls, and was decreased by treatment with cinaciguat (an sGC activator), but not riociguat (an sGC stimulator). Stimulated platelet lysate sGC activity was increased with PE compared with controls. CONCLUSIONS In patients with acute submassive PE, despite evidence of adequate drug delivery, inhaled NO had no major effect on platelet O2 consumption or agonist-stimulated parameters on TEG. Pharmacological activation, but not stimulation, of sGC effectively decreased platelet cytosolic [Ca++], and platelet sGC activity was increased with PE, confirming the viability of sGC as a therapeutic target.
-
3.
Differential effects of testosterone on circulating neutrophils, monocytes, and platelets in men: Findings from two trials.
Gagliano-Jucá, T, Pencina, KM, Guo, W, Li, Z, Huang, G, Basaria, S, Bhasin, S
Andrology. 2020;(5):1324-1331
-
-
Free full text
-
Abstract
BACKGROUND Testosterone treatment increases erythrocytes in men, but its effects on leukocyte and platelet counts are unknown and could affect its safety. OBJECTIVE To determine whether testosterone affects circulating leukocytes and platelets in men. METHODS Secondary analyses of two randomized testosterone trials were performed: the 5α-reductase (5aR) and OPTIMEN trials. In 5aR trial, 102 healthy men, 21-50 years (mean age 38), received a long-acting GnRH agonist, and 50, 125, 300, or 600 mg/week testosterone enanthate (TE) plus placebo or 2.5 mg/ day dutasteride for 20 weeks. In OPTIMEN, 78 functionally limited men, ≥65 years (mean age 72) with protein intake ≤ 0.83 g kg-1 day-1 , were randomized to controlled diets with 0.8 g kg-1 day-1 protein or 1.3 g kg-1 day-1 protein plus placebo or TE (100 mg/week) for 6 months. Changes from baseline in total and differential leukocyte count, and platelet count were evaluated. RESULTS In 5aR, testosterone administration was associated with increases in total leukocyte (estimated change from baseline 40, 490, 1230, and 1280 cells/µL, P < .001), neutrophil (65.1, 436.1, 1177.2, and 1192.2 cells/µL, P < .001), monocyte (-20.2, 24.5, 90.6, and 143.9 cells/µL, P < .001), platelet (-7.3, 8.4, 8.7, and 8.9 × 103 cells/µL, P = .033), and erythrocyte counts. Testosterone did not affect absolute lymphocyte count. Similar increase in total leukocyte count was observed with testosterone treatment in OPTIMEN (change 0.77 × 103 cells/µL, P vs placebo = 0.004). CONCLUSIONS Testosterone administration in men differentially increases neutrophil and monocyte counts. These findings, together with its erythropoietic effects, suggest that testosterone promotes the differentiation of hematopoietic progenitors into the myeloid lineage. These findings have potential mechanistic, therapeutic, and safety implications.
-
4.
Delayed increase of thrombocyte levels after a single sub-anesthetic dose of ketamine - A randomized trial.
Colic, L, Woelfer, M, Colic, M, Leutritz, AL, Liebe, T, Fensky, L, Sen, ZD, Li, M, Hoffmann, J, Kretzschmar, MA, et al
European neuropsychopharmacology : the journal of the European College of Neuropsychopharmacology. 2018;(6):701-709
Abstract
Recently, ketamine has been investigated as a potential antidepressant option for treatment resistant depression. Unlike traditional drugs, it yields immediate effects, most likely via increased glutamatergic transmission and synaptic plasticity. However, ketamine administration in humans is systemic and its long-term impact on blood parameters has not yet been described in clinical studies. Here we investigated potential sustained effects of ketamine administration (0.5 mg/kg ketamine racemate) on hematological and biochemical values in plasma and serum in a randomized double-blinded study. 80 healthy young participants were included and whole blood samples were collected 5 days before, and 14 days after the infusion. To assess the group effect, repeated measure analyses of co-variance (rmANCOVA) were conducted for the following blood parameters: levels of sodium, potassium, calcium, hemoglobin and number of erythrocytes, lymphocytes, and thrombocytes. RmANCOVA revealed a significant time by treatment effect on thrombocyte levels (F1, 74 = 13.54, p < 0.001, eta = 0.155), driven by an increase in the ketamine group (paired t-test, t = -3.51, df = 38, p = 0.001). Specificity of thrombocyte effect was confirmed by logistic regression, and in addition, no other coagulation parameters showed significant interaction. Moreover, the relative increase in the ketamine group was stable across sexes and not predicted by age, BMI, smoking, alcohol or drug use, and contraception. Our results describe aftereffects of sub-anesthetic ketamine administration on blood coagulation parameters, which should be considered especially when targeting psychiatric populations with relevant clinical comorbidities.
-
5.
A switch to a raltegravir containing regimen does not lower platelet reactivity in HIV-infected individuals.
van der Heijden, WA, van Crevel, R, de Groot, PG, Urbanus, RT, Koenen, HJPM, Bosch, M, Keuter, M, van der Ven, AJ, de Mast, Q
AIDS (London, England). 2018;(17):2469-2475
Abstract
OBJECTIVE Platelet hyperreactivity and increased platelet-monocyte aggregation (PMA) are associated with increased cardiovascular risk and inflammation. In a previous cross-sectional study, individuals using a raltegravir (RAL)-based regimen were found to have reduced platelet reactivity and PMA compared with other antiretroviral regimens. Our aim was to investigate whether switching from a nonintegrase inhibitor regimen to a RAL-based regimen reduces platelet reactivity or PMA. DESIGN An investigator initiated, single-centre, prospective randomized, open-label, blinded endpoint trial. METHODS Forty HIV-infected adults using a nonintegrase inhibitor containing regimen with undetectable viral load were randomized to either continue their regimen or switch to a RAL-based regimen for 10 weeks, continuing the same backbone. The primary outcome was the change in platelet reactivity at week 10, which was determined as the expression of the platelet activation marker P-selectin and binding of fibrinogen before and after ex-vivo stimulation with different platelet agonists. Secondary outcomes included PMA, plasma markers of platelet activation and markers of inflammation and immune cell activation. RESULTS Twenty-one participants were enrolled in the continuation group and 19 in the RAL group. Baseline characteristics were comparable between groups. There were no differences in the change in platelet reactivity to either platelet agonist at week 10, nor in plasma markers of platelet activation. PMA, C-reactive protein, T-cell activation (CD38HLA-DR) and monocyte (CD14CD16) subsets. CONCLUSION Switching a nonintegrase inhibitor containing regimen to a RAL-based regimen does not reduce platelet reactivity, platelet-leukocyte aggregation, inflammation and immune activation in virologically suppressed HIV-infected individuals. CLINICAL TRIAL NUMBER NCT02383355.
-
6.
Wine consumption reduced postprandial platelet sensitivity against platelet activating factor in healthy men.
Xanthopoulou, MN, Kalathara, K, Melachroinou, S, Arampatzi-Menenakou, K, Antonopoulou, S, Yannakoulia, M, Fragopoulou, E
European journal of nutrition. 2017;(4):1485-1492
Abstract
PURPOSE Platelet activating factor (PAF) is a potent inflammatory and thrombotic mediator that participates in the initiation and prolongation of atherosclerosis. The aim of the present study was to evaluate the potential effect of wine consumption on platelet aggregation against PAF. METHODS The study had cross-over design. Ten healthy men participated in four daily trials on separate days: They consumed a standardized meal along with white wine, Robola variety (trial R), or red wine, Cabernet Sauvignon variety (trial CS), or an ethanol solution (trial E), or water (trial W). Blood samples were collected before and after meal consumption and at several time points during the next 6 h. Platelet aggregation against PAF (EC50 values) and several blood biomarkers were measured, and incremental areas under the curve (iAUC) were calculated. RESULTS A significant trial effect was found in platelet sensitivity against PAF (p trial = 0.01). Moreover, the iAUC-PAF EC50 of CS trial was higher compared to both iAUC-PAF EC50 of E and W trials (P = 0.04, P = 0.02). Plasminogen activator inhibitor-1 iAUC was higher in all alcoholic beverages compare with the one of W trial (P E = 0.05, P R = 0.01, P CS = 0.01). Triacylglycerol iAUC increased significantly only in E compared to W trial (P = 0.04) and were significantly lower at 60-120 min in wine trials compared to the one of E (P < 0.05). CONCLUSIONS Wine consumption improved platelet sensitivity independently of alcohol, kept triacylglycerols at lower levels during their postprandial elevation, and did not affect plasminogen activator inhibitor-1 levels more adversely than ethanol per se.
-
7.
Conjugated Linoleic Acid Modulates Clinical Responses to Oral Nitrite and Nitrate.
Hughan, KS, Wendell, SG, Delmastro-Greenwood, M, Helbling, N, Corey, C, Bellavia, L, Potti, G, Grimes, G, Goodpaster, B, Kim-Shapiro, DB, et al
Hypertension (Dallas, Tex. : 1979). 2017;(3):634-644
-
-
Free full text
-
Abstract
Dietary NO3- (nitrate) and NO2- (nitrite) support ˙NO (nitric oxide) generation and downstream vascular signaling responses. These nitrogen oxides also generate secondary nitrosating and nitrating species that react with low molecular weight thiols, heme centers, proteins, and unsaturated fatty acids. To explore the kinetics of NO3-and NO2-metabolism and the impact of dietary lipid on nitrogen oxide metabolism and cardiovascular responses, the stable isotopes Na15NO3 and Na15NO2 were orally administered in the presence or absence of conjugated linoleic acid (cLA). The reduction of 15NO2- to 15NO was indicated by electron paramagnetic resonance spectroscopy detection of hyperfine splitting patterns reflecting 15NO-deoxyhemoglobin complexes. This formation of 15NO also translated to decreased systolic and mean arterial blood pressures and inhibition of platelet function. Upon concurrent administration of cLA, there was a significant increase in plasma cLA nitration products 9- and 12-15NO2-cLA. Coadministration of cLA with 15NO2- also impacted the pharmacokinetics and physiological effects of 15NO2-, with cLA administration suppressing plasma NO3-and NO2-levels, decreasing 15NO-deoxyhemoglobin formation, NO2-inhibition of platelet activation, and the vasodilatory actions of NO2-, while enhancing the formation of 9- and 12-15NO2-cLA. These results indicate that the biochemical reactions and physiological responses to oral 15NO3-and 15NO2-are significantly impacted by dietary constituents, such as unsaturated lipids. This can explain the variable responses to NO3-and NO2-supplementation in clinical trials and reveals dietary strategies for promoting the generation of pleiotropic nitrogen oxide-derived lipid signaling mediators. Clinical Trial Registration- URL: http://www.clinicaltrials.gov . Unique identifier: NCT01681836.
-
8.
Effect of 1-y oral supplementation with vitaminized olive oil on platelets from healthy postmenopausal women.
Vignini, A, Nanetti, L, Raffaelli, F, Sabbatinelli, J, Salvolini, E, Quagliarini, V, Cester, N, Mazzanti, L
Nutrition (Burbank, Los Angeles County, Calif.). 2017;:92-98
Abstract
OBJECTIVE Olive oil is the main fat source in the Mediterranean diet and shows a protective role against aging and related diseases. Osteoporosis represents a serious health problem worldwide and is associated with an increased risk for fractures and mortality. Nutrition should be part of bone disease prevention strategies, especially in light of the aging population and the effect of diet on bone health. The aim of this study was to investigate whether oral supplementation with extra virgin olive oil (VOO) enriched with vitamins D3, K1, and B6 (VitVOO) is able to modify some physicochemical and functional plasma membrane properties and nitrosative stress markers status. METHODS In this single-center, randomized placebo-controlled trial, 60 postmenopausal women were administered either VitVOO or placebo (PlaVOO). After 1 y of oral supplementation, platelet membrane fluidity changes, Na+/K+-ATPase activity, serum nitric oxide, and peroxynitrite levels were determined in participants. RESULTS After 1 y (time 1), women taking VitVOO showed lower nitric oxide levels than those taking PlaVOO; the same trend was found for peroxynitrite levels. As far as membrane fluidity was concerned, a significant decrease in anisotropy of diphenylhexatriene and trimethylammonium-diphenylhexatriene at time 1 in VitVOO participants compared with PlaVOO was found. Finally, Na+/K+-ATPase activity showed a significant increase after VitVOO supplementation. CONCLUSION The supplementation of VitVOO into the diet of postmenopausal women could represent a proper tool for platelet function and a useful strategy against nitrosative stress and related diseases, thus confirming the antioxidant role played by the added vitamins.
-
9.
Platelet reactivity in patients with venous thrombosis who use rosuvastatin: a randomized controlled clinical trial.
Biedermann, JS, Cannegieter, SC, Roest, M, van der Meer, FJ, Reitsma, PH, Kruip, MJ, Lijfering, WM
Journal of thrombosis and haemostasis : JTH. 2016;(7):1404-9
-
-
Free full text
-
Abstract
UNLABELLED Essentials Statins, especially rosuvastatin, may reduce venous thrombosis risk, but the mechanism is unclear. We performed a randomized trial investigating the effect of rosuvastatin on platelet reactivity. Thromboxane-A2 mediated platelet aggregation was measured before and after rosuvastatin therapy. Rosuvastatin did not inhibit thromboxane-mediated platelet aggregation in venous thrombosis patients. SUMMARY Background Statins may exert a protective effect against the risk of venous thrombosis (VT), but the mechanism is unclear. Objectives In this open-label, randomized clinical trial (www.clinicaltrials.gov NCT01613794), we aimed to determine the ex vivo effect of rosuvastatin on platelet reactivity in patients with a history of VT. Methods Platelet reactivity, in platelet reaction units (PRUs), was measured at baseline and after 28 days with VerifyNow, which uses arachidonic acid to determine thromboxane-mediated platelet aggregation, in 50 consecutive patients included in our study (25 receiving rosuvastatin and 25 without intervention). Results Forty-seven of 50 (94.0%) consecutively enrolled patients had two valid PRU measurements. The mean PRUs in rosuvastatin users were 609 at baseline and 613 at the end of the study (mean change 5; 95% confidence interval [CI] - 18 to 27). The mean PRUs in non-users were 620 at baseline and 618 at the end of the study (mean change - 2; 95% CI - 15 to 12). The mean difference in PRU change between users and non-users was 6 (95% CI - 20 to 33). After exclusion of patients who used antiplatelet medication, or had thrombocytopenia, similar results were obtained, i.e. no apparent effect of rosuvastatin on PRUs, with a mean difference in PRU change between users and non-users of - 1 (95% CI - 20 to 19). Conclusions Rosuvastatin does not affect platelet reactivity when arachidonic acid is used as an agonist in patients with a history of VT.
-
10.
Moderate intake of docosahexaenoic acid raises plasma and platelet vitamin E levels in cystic fibrosis patients.
Véricel, E, Mazur, S, Colas, R, Delaup, V, Calzada, C, Reix, P, Durieu, I, Lagarde, M, Bellon, G
Prostaglandins, leukotrienes, and essential fatty acids. 2016;:41-47
Abstract
Patients with cystic fibrosis have increased oxidative stress and impaired antioxidant systems. Moderate intake of docosahexaenoic acid (DHA) may favor the lowering of oxidative stress. In this randomized, double-blind, cross-over study, DHA or placebo capsules, were given daily to 10 patients, 5mg/kg for 2 weeks then 10mg/kg DHA for the next 2 weeks (or placebo). After 9 weeks of wash-out, patients took placebo or DHA capsules. Biomarkers of lipid peroxidation and vitamin E were measured at baseline, and after 2 and 4 weeks of treatment in each phase. The proportions of DHA increased both in plasma and platelet lipids after DHA supplementations. The lipid peroxidation markers did not significantly decrease, in spite of a trend, after the first and/or the second dose of DHA but plasma and platelet vitamin E amounts increased significantly after DHA supplementation. Our findings reinforce the antioxidant potential of moderate DHA intake in subjects displaying increased oxidative stress.