Project description:BackgroundPrior studies have suggested an association between platelet transfusions (PTXs) and worse outcomes among infants with necrotizing enterocolitis (NEC), potentially mediated by proinflammatory factors released by platelets. However, the effects of storage on platelet proinflammatory factor release and the confounding role of illness severity on NEC outcomes have not been determined.Study design and methodsFirst, neuropeptide Y (a potent splanchnic vasoconstrictor released by platelets) was measured by enzyme-linked immunosorbent assay in fresh frozen plasma and in the supernatant of leukoreduced apheresis-derived platelets at different times during storage. Next, we evaluated the relationship between PTX rates and death in a multicenter cohort of very-low-birth-weight infants with NEC, adjusting for illness severity.ResultsNeuropeptide Y levels increased over time in the supernatant of leukoreduced apheresis-derived platelets and were 4.4-fold and 8.9-fold higher than in fresh frozen plasma on Days 2 and 3 of storage, respectively (p < 0.001). Among 598 very-low-birth-weight infants, 44 developed NEC. In unadjusted analysis, PTX rate was 30.3 (95% confidence interval [CI], 11.5-80.1) per 100 infant-days among infants who died, compared to 6.0 (95% CI, 3.2-11.2) among survivors (incidence rate ratio, 5.1; 95% CI, 1.6-16.2; p = 0.006). In multivariable analysis, there was no association between PTX rate and mortality (incidence rate ratio, 3.0; 95% CI, 0.6-15.0; p = 0.18), although estimation was imprecise.ConclusionProinflammatory mediators accumulate in platelet suspensions during storage. Although PTX rates were not associated with increased mortality among infants with NEC in our study, our estimates suggest the potential for such an association that needs evaluation in larger studies.
Project description:BackgroundWe conducted a trial of prophylactic platelet transfusions to evaluate the effect of platelet dose on bleeding in patients with hypoproliferative thrombocytopenia.MethodsWe randomly assigned hospitalized patients undergoing hematopoietic stem-cell transplantation or chemotherapy for hematologic cancers or solid tumors to receive prophylactic platelet transfusions at a low dose, a medium dose, or a high dose (1.1x10(11), 2.2x10(11), or 4.4x10(11) platelets per square meter of body-surface area, respectively), when morning platelet counts were 10,000 per cubic millimeter or lower. Clinical signs of bleeding were assessed daily. The primary end point was bleeding of grade 2 or higher (as defined on the basis of World Health Organization criteria).ResultsIn the 1272 patients who received at least one platelet transfusion, the primary end point was observed in 71%, 69%, and 70% of the patients in the low-dose group, the medium-dose group, and the high-dose group, respectively (differences were not significant). The incidences of higher grades of bleeding, and other adverse events, were similar among the three groups. The median number of platelets transfused was significantly lower in the low-dose group (9.25x10(11)) than in the medium-dose group (11.25x10(11)) or the high-dose group (19.63x10(11)) (P=0.002 for low vs. medium, P<0.001 for high vs. low and high vs. medium), but the median number of platelet transfusions given was significantly higher in the low-dose group (five, vs. three in the medium-dose and three in the high-dose group; P<0.001 for low vs. medium and low vs. high). Bleeding occurred on 25% of the study days on which morning platelet counts were 5000 per cubic millimeter or lower, as compared with 17% of study days on which platelet counts were 6000 to 80,000 per cubic millimeter (P<0.001).ConclusionsLow doses of platelets administered as a prophylactic transfusion led to a decreased number of platelets transfused per patient but an increased number of transfusions given. At doses between 1.1x10(11) and 4.4x10(11) platelets per square meter, the number of platelets in the prophylactic transfusion had no effect on the incidence of bleeding. (ClinicalTrials.gov number, NCT00128713.)
Project description:Acute platelet transfusion after intracerebral hemorrhage (ICH) given in efforts to reverse antiplatelet medication effects and prevent ongoing bleeding does not appear to improve outcome and may be associated with harm. Although the underlying mechanisms are unclear, the influence of ABO-incompatible platelet transfusions on ICH outcomes has not been investigated. We hypothesized that patients with ICH who receive ABO-incompatible platelet transfusions would have worse platelet recovery (using absolute count increment [ACI]) and neurological outcomes (mortality and poor modified Rankin Scale [mRS 4-6]) than those receiving ABO-compatible transfusions. In a single-center cohort of consecutively admitted patients with ICH, we identified 125 patients receiving acute platelet transfusions, of whom 47 (38%) received an ABO-incompatible transfusion. Using quantile regression, we identified an association of ABO-incompatible platelet transfusion with lower platelet recovery (ACI, 2 × 103cells per μL vs 15 × 103cells per μL; adjusted coefficient β, -19; 95% confidence interval [CI], -35.55 to -4.44; P = .01). ABO-incompatible platelet transfusion was also associated with increased odds of mortality (adjusted odds ratio [OR], 2.59; 95% CI, 1.00-6.73; P = .05) and poor mRS (adjusted OR, 3.61; 95% CI, 0.97-13.42; P = .06); however, these estimates were imprecise. Together, these findings suggest the importance of ABO compatibility for platelet transfusions for ICH, but further investigation into the mechanism(s) underlying these observations is required.
Project description:Platelet transfusion is one of the most crucial therapeutic approaches in Medicine. However, severe and fatal adverse reactions may develop. In addition to their important function in hemostasis, platelets' role in inflammation has become more evident. Recently, platelets are also recognized as the main source of circulating soluble CD40 ligand (sCD40L, (CD154)), which plays significant roles in hemostasis, platelet activation, clot stability, interactions with other cells, and upregulation of different mediators. In this review, we will briefly highlight the importance of platelet transfusion, its role in inflammatory and thrombotic transfusion reactions, and visit the most recent findings on sCD40L.
Project description:BackgroundThrombocytopenia is frequent among neonates, and 20-25% of affected infants are treated with platelet transfusions. These are frequently given for mild thrombocytopenia (platelets: 50-100 × 10(9) L(-1)), largely because of the known hyporeactivity of neonatal platelets. In tests of primary hemostasis, however, neonates have shorter bleeding and closure times (CTs) than adults. This has been attributed to their higher hematocrits, higher von Willebrand factor (VWF) concentrations, and predominance of longer VWF polymers.ObjectiveTo determine whether the 'transfusion' of adult (relatively hyperreactive) platelets into neonatal blood results in a hypercoagulable profile.MethodsCord blood (CB) and adult peripheral blood (PB) were separated (with a modified buffy coat method) to generate miniaturized platelet concentrates (PCs) and thrombocytopenic blood. PB-derived and CB-derived PCs (n = 7 per group) were then 'transfused'in vitro into thrombocytopenic CB and PB. The effects of autologous vs. allogeneic (developmentally mismatched) 'transfusions' were evaluated with whole blood aggregometry, a platelet function analyzer (PFA-100), and thromboelastography (TEG).ResultsAdult platelets aggregated significantly better than neonatal platelets in response to thrombin receptor-activating peptide, ADP, and collagen, regardless of the blood into which they were transfused. The 'transfusion' of adult platelets into thrombocytopenic CB resulted in shorter CTs-EPI (PFA-100) and higher clot strength and firmness (TEG) than 'transfusion' of neonatal autologous platelets.ConclusionsIn vitro'transfusion' of adult platelets into neonatal blood results in shorter CTs than 'transfusion' with neonatal platelets. Our findings should raise awareness of the differences between the neonatal and adult hemostatic system and the potential 'developmental mismatch' associated with platelet transfusions for neonatal hemostasis.
Project description:The revised Common Rule requires using a single institutional review board (sIRB) for U.S.-based, multisite, nonexempt, federally conducted or supported research with human participants. The 21st Century Cures Act directs the Department of Health and Human Services (HHS) to harmonize differences between HHS and the U.S. Food and Drug Administration (FDA) regulations governing research with humans. Anticipating that the FDA may update its 2006 centralized IRB guidance, we conducted interviews with 34 stakeholders engaged in FDA-regulated clinical research to identify benefits and challenges of using sIRBs and to gather recommendations for revising the FDA's guidance. The main benefits were consistency and standardization, speed and efficiency, and streamlining and simplification. The main challenges were uncertainty at local institutions, including addressing local context; decreased timeliness of the research review process; variable processes; and insufficient communication. Several recommendations for FDA guidance focused on the local context and communication plans. Findings suggest that the sIRB review process may be gaining efficiency although challenges remain.
Project description:AimMitochondrial dysfunction is a critical factor in the pathogenesis of septic cardiomyopathy (SCM). Mitochondrial anchored protein ligase (MAPL), a small ubiquitin-like modifier (SUMO) E3 ligase, plays a significant role in mitochondrial function. However, the role of MAPL in SCM remains unclear.MethodsTo investigate the role of MAPL in SCM, cardiomyocyte-specific MAPL knockout mice were generated. A cecal ligation and puncture (CLP) procedure was employed to induce a sepsis-like condition.ResultsThe expression of MAPL in heart tissues and H9C2 cardiomyocytes was elevated following CLP challenge or lipopolysaccharide (LPS) stimulation. MAPL deficiency ameliorated CLP-induced cardiac injury, dysfunction, and inflammation, and also improved the survival rate of mice following CLP operation. Additionally, MAPL deficiency or knockdown inhibited LPS-induced cardiomyocyte apoptosis, improved mitochondrial structural abnormalities, and increased ATP production. Furthermore, MAPL knockdown mitigated LPS-induced reductions in mitochondrial membrane potential (MMP) and intracellular reactive oxygen species (ROS) production. Mechanistically, the expression of dynamin-related protein 1 (drp1) in the mitochondria of heart tissues or H9C2 cardiomyocytes was elevated under septic conditions. Accordingly, the SUMOylation of drp1 in heart tissues or H9C2 cardiomyocytes was increased under sepsis conditions, which was reduced by MAPL knockout or knockdown.ConclusionOur results reveal that MAPL promotes cardiac injury/dysfunction and inflammation in SCM. Deficiency or knockdown of MAPL alleviates SCM by reducing drp1 SUMOylation as well as drp1-mediated mitochondrial dysfunction. These findings suggest that targeting MAPL may represent a therapeutic strategy for patients with SCM.
Project description:ObjectiveTo evaluate the immediate effects of red blood cell transfusion on central venous oxygen saturation and lactate levels in septic shock patients with different transfusion triggers.MethodsWe included patients with a diagnosis of septic shock within the last 48 hours and hemoglobin levels below 9.0 g/dL Patients were randomized for immediate transfusion with hemoglobin concentrations maintained above 9.0 g/dL (Group Hb9) or to withhold transfusion unless hemoglobin felt bellow 7.0 g/dL (Group Hb7). Hemoglobin, lactate, central venous oxygen saturation levels were determined before and one hour after each transfusion.ResultsWe included 46 patients and 74 transfusions. Patients in Group Hb7 had a significant reduction in median lactate from 2.44 (2.00 - 3.22) mMol/L to 2.21 (1.80 - 2.79) mMol/L, p = 0.005, which was not observed in Group Hb9 [1.90 (1.80 - 2.65) mMol/L to 2.00 (1.70 - 2.41) mMol/L, p = 0.23]. Central venous oxygen saturation levels increased in Group Hb7 [68.0 (64.0 - 72.0)% to 72.0 (69.0 - 75.0)%, p < 0.0001] but not in Group Hb9 [72.0 (69.0 - 74.0)% to 72.0 (71.0 - 73.0)%, p = 0.98]. Patients with elevated lactate or central venous oxygen saturation < 70% at baseline had a significant increase in these variables, regardless of baseline hemoglobin levels. Patients with normal values did not show a decrease in either group.ConclusionRed blood cell transfusion increased central venous oxygen saturation and decreased lactate levels in patients with hypoperfusion regardless of their baseline hemoglobin levels. Transfusion did not appear to impair these variables in patients without hypoperfusion. ClinicalTrials.gov NCT01611753.