Effect Of Whole Blood Research Articles

The Efficacy of Whole Blood Resuscitation During Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) to Mitigate Post-occlusion Circulatory Collapse: A Translational Model in Large Swine.

Uncontrolled torso hemorrhage is the primary cause of potentially survivable deaths on the battlefield. Zone 1 Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA), in conjunction with damage control resuscitation, may be an effective management strategy for these patients in the prehospital or austere phase of their care. However, the effect of whole blood (WB) transfusion during REBOA on post-occlusion circulatory collapse is not fully understood. Yorkshire male swine (n = 6 per group, 70-90 kg) underwent a 40% volume-controlled hemorrhage. After a 10-minute hemorrhagic shock period, a REBOA balloon was inflated in Zone 1. Fifteen minutes after inflation, 0, 1, or 3 units (450 mL/unit) of autologous WB was infused through the left jugular vein. Thirty minutes after initial balloon inflation, the balloon was deflated slowly over 3 minutes. Following deflation, normal saline was administered (up to 3,000 mL) and swine were observed for 2 hours. Survival (primary outcome), hemodynamics, and blood gas values were compared among groups. Statistical significance was determined by log-rank test, one-way ANOVA, and repeated measures ANOVA. Survival rates were comparable between groups (P = .345) with 66% of control, 33% of the one-unit animals, and 50% of the 3-unit animals survived until the end of the study. Following WB infusion, both the 1-unit and the 3-unit groups had significantly higher blood pressure (P < .01), pulmonary artery pressure (P < .01), and carotid artery flow (P < .01) compared to the control group. WB transfusion during Zone 1 REBOA was not associated with increased short-term survival in this large animal model of severe hemorrhage. We observed no signal that WB transfusion may mitigate post-occlusion circulatory collapse. However, there was evidence of supra-normal blood pressures during WB transfusion.

FINDING THE SWEET SPOT: THE ASSOCIATION BETWEEN WHOLE BLOOD TO RED BLOOD CELLS RATIO AND OUTCOMES OF HEMORRHAGING CIVILIAN TRAUMA PATIENTS.

Purpose: To evaluate the dose-dependent effect of whole blood (WB) on the outcomes of civilian trauma patients with hemorrhagic shock. Methods: We performed a 2-year (2020-2021) retrospective analysis of the ACS-TQIP dataset. Adult (≥18) trauma patients with a shock index (SI) >1 who received at least 5 units of PRBC and one unit of WB within the first 4 h of admission were included. Primary outcomes were 6-h, 24-h, and in-hospital mortality. Secondary outcomes were major complications and hospital and intensive care unit length of stay. Results: A total of 830 trauma patients with a mean (SD) age of 38 (16) were identified. The median [IQR] 4-h WB and PRBC requirements were 2 [2-4] U and 10 [7-15] U, respectively, with a median WB:RBC ratio of 0.2 [0.1-0.3]. Every 0.1 increase in WB:RBC ratio was associated with decreased odds of 24-h mortality (aOR: 0.916, P = 0.035) and in-hospital mortality (aOR: 0.878, P < 0.001). Youden's index identified 0.25 (1 U of WB for every 4 U of PRBC) as the optimal WB:PRBC ratio to reduce 24-h mortality. High ratio (≥0.25) group had lower adjusted odds of 24-h mortality (aOR: 0.678, P = 0.021) and in-hospital mortality (aOR: 0.618, P < 0.001) compared to the low ratio group. Conclusions: A higher WB:PRBC ratio was associated with improved early and late mortality in trauma patients with hemorrhagic shock. Given the availability of WB in trauma centers across the United States, at least one unit of WB for every 4 units of packed red blood cells may be administered to improve the survival of hemorrhaging civilian trauma patients.

Volume replacement in the resuscitation of trauma patients with acute hemorrhage: an umbrella review

BackgroundThe use of intravenous fluid therapy in patients with major trauma in prehospital settings is still controversial. We conducted an umbrella review to evaluate which is the best volume expansion in the resuscitation of a hemorrhagic shock to support the development of major trauma guideline recommendations.MethodsWe searched PubMed, Embase, and CENTRAL up to September 2022 for systematic reviews (SRs) investigating the use of volume expansion fluid on mortality and/or survival. Quality assessment was performed using AMSTAR 2 and the Certainty of the evidence was assessed with the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach.ResultsWe included 14 SRs investigating the effects on mortality with the comparisons: use of crystalloids, blood components, and whole blood. Most SRs were judged as critically low with slight overlapping of primary studies and high consistency of results. For crystalloids, inconsistent evidence of effectiveness in 28- to 30-day survival (primary endpoint) was found for the hypertonic saline/dextran group compared with isotonic fluid solutions with moderate certainty of evidence. Pre-hospital blood component infusion seems to reduce mortality, however, as the certainty of evidence ranges from very low to moderate, we are unable to provide evidence to support or reject its use. The blood component ratio was in favor of higher ratios among all comparisons considered with moderate to very low certainty of evidence. Results about the effects of whole blood are very uncertain due to limited and heterogeneous interventions in studies included in SRs.ConclusionHypertonic crystalloid use did not result in superior 28- to 30-day survival. Increasing evidence supports the scientific rationale for early use of high-ratio blood components, but their use requires careful consideration. Preliminary evidence is very uncertain about the effects of whole blood and further high-quality studies are required.

The Effect of Whole Blood and Bone Marrow with the Addition of Pyrimidine-2,4(1h,3h)-dione Thietanyl Derivatives on Free Radical Oxidation.

It is relevant to study the general patterns and identify non-specific mechanisms of body protective and adaptive reactions violation, which can lead to the various pathological processes and develop principles for the correction of these disorders. One of the therapy and prevention directions is the search for new medicines. In recent years, new derivatives of pyrimidine bases have been synthesized and studied. Pyrimidine-based medicines have a membrane-stabilizing and immunomodulatory effect and can normalize metabolic disorders and increase the oxidative activity of leukocytes. Disruption of the free radical oxidation processes, the generation of reactive oxygen species and lipid peroxidation, including in whole blood and bone marrow, has gained importance in recent years. Each reaction was monitored by thin layer chromatography. 1H, 13C, and 15N NMR spectra were recorded (chemical shifts were expressed as δ-values). We studied the effect of 6-methyl-3-(thietan- 3-yl)pyrimidine-2,4(1H,3H)-dione on the generation of reactive oxygen species (ROS) in the whole blood and bone marrow using the study of whole blood spontaneous and stimulated chemiluminescence (CL). CL methods make it possible to quickly and easily assess the studied material (whole blood, bone marrow) effect on free radical oxidation. Using CL methods, it is possible to reveal the presence of medicines' pro- or antioxidant properties, opening up new possibilities in the search for substances with antioxidant properties and comparing their activity. Alkylation of 6-methylpyrimidine-2,4(1H,3H)-dione by 2-chloromethylthiirane in protic solvents in the presence of alkali leads to the formation of an N-thietane derivative. NMR spectroscopy showed that 6-methylpyrimidine-2,4(1H,3H)-dione was alkylated at position 3. The oxidation reactions of N-(thietan-3-yl)pyrimidine-2,4(1H,3H)-dione were studied, and it was determined that, depending on the excess of the oxidizing agent and the duration of the process, N-(1-oxothietan-3-yl)- or N-(1,1-- dioxothietan-3-yl)pyrimidine-2,4(1H,3H)-diones were formed. The effects of free radical oxidation processes of new biologically active pyrimidine-2,4(1H,3H)-diones were studied. New pyrimidine-2,4(1H,3H)-diones increase the general adaptive capabilities of the body and have protective effects in extreme conditions.

Science, Medicine, and the Anesthesiologist

Science, Medicine, and the Anesthesiologist

A comparison of an optimized automated sample preparation of PEth in blood pretreated by freezing versus manual preparation in whole blood, analyzing by UHPLC – MS/MS

A robust and simple high-throughput automatic sample preparation in a 96-well plate format for quantification of PEth16:0/18:1 with UHPLC-MS/MS in pre-treated frozen blood samples has been simplified as well as optimised regarding liquid handling parameters. To keep the air cushion in the pipetting step as small as possible, 300 µl pipette tips were used instead of 1000 µl tips for pipetting the minimum volume of 2-propanol required for the sample preparation. The 96-well plate was mixed vigorously to acquire a good reproducibility of the PEth results. A 96-wellplate with a well volume of 2.0 ml was used to eliminate cross contamination between the wells, and the calibration curve covered a concentration range from 0.03 to 5 µmol/l. The method was sensitive, and the limit of quantification was 0.005 µmol/l for PEth. The matrix effect in whole blood was small and corrected to 106% by using an isotope-labelled internal standard. There was no carry-over observed after the highest standard 5 µmol/l. The intermediate precision and accuracy were, respectively, less than 9% and 101% when using both the automated and manual sample preparation method. 19 external controls were analysed from an Equalis proficiency testing program for a period of 16 months, and our results were always within 79% of the assigned value. 114 samples were analysed by manual and automatic sample preparation with UHPLC-MS/MS in respectively whole blood and pre-treated frozen blood samples. The mean percentage difference of these measurements between the two methods was calculated in accordance with (Bland & Altman) to be (−4.8 ± 5.6) %.

Whole Blood Holding Time Prior to Plasma Processing Alters microRNA Expression Profile.

MicroRNAs (miRNAs) can exhibit aberrant expression under different physiological and pathological conditions. Therefore, differentially expressed circulating miRNAs have been a focus of biomarker discovery research. However, the use of circulating miRNAs comes with challenges which may hinder the reliability for their clinical application. These include varied sample collection protocols, storage times/conditions, sample processing and analysis methods. This study focused on examining the effect of whole blood holding time on the stability of plasma miRNA expression profiles. Whole blood samples were collected from healthy pregnant women and were held at 4°C for 30 min, 2 h, 6 h or 24 h prior to processing for plasma isolation. Plasma RNA was extracted and the expression of 179 miRNAs were analyzed. Unsupervised principal component analysis demonstrated that whole blood holding time was a major source of variation in miRNA expression profiles with 53 of 179 miRNAs showing significant changes in expression. Levels of specific miRNAs previously reported to be associated with pregnancy-associated complications such as hsa-miR-150-5p, hsa-miR-191-5p, and hsa-miR-29a-3p, as well as commonly used endogenous miRNA controls, hsa-miR-16-5p, hsa-miR-25-3p, and hsa-miR-223-3p were significantly altered with increase in blood holding time. Current protocols for plasma-based miRNA profiling for diagnostics describe major differences in whole blood holding periods ranging from immediately after collection to 26 h after. Our results demonstrate holding time can have dramatic effects on analytical reliability and reproducibility. This highlights the importance of standardization of blood holding time prior to processing for plasma in order to minimize introduction of non-biological variance in miRNA profiles.

Genetic variants at the RTP4/MASP1 locus are associated with fatigue in Scandinavian patients with primary Sjögren’s syndrome

ObjectivesFatigue is common and severe in primary Sjögren’s syndrome (pSS). The aim of this study was to identify genetic determinants of fatigue in pSS through a genome-wide association study.MethodsPatients with...

Monitoring DOACs with a Novel Dielectric Microsensor: A Clinical Study.

There are acute settings where assessing the anticoagulant effect of direct oral anticoagulants (DOACs) can be useful. Due to variability among routine coagulation tests, there is an unmet need for an assay that detects DOAC effects within minutes in the laboratory or at the point of care. We developed a novel dielectric microsensor, termed ClotChip, and previously showed that the time to reach peak permittivity (T peak) is a sensitive parameter of coagulation function. We conducted a prospective, single-center, pilot study to determine its clinical utility at detecting DOAC anticoagulant effects in whole blood. We accrued 154 individuals: 50 healthy volunteers, 49 rivaroxaban patients, 47 apixaban, and 8 dabigatran patients. Blood samples underwent ClotChip measurements and plasma coagulation tests. Control mean T peak was 428 seconds (95% confidence interval [CI]: 401-455 seconds). For rivaroxaban, mean T peak was 592 seconds (95% CI: 550-634 seconds). A receiver operating characteristic curve showed that the area under the curve (AUC) predicting rivaroxaban using T peak was 0.83 (95% CI: 0.75-0.91, p < 0.01). For apixaban, mean T peak was 594 seconds (95% CI: 548-639 seconds); AUC was 0.82 (95% CI: 0.73-0.91, p < 0.01). For dabigatran, mean T peak was 894 seconds (95% CI: 701-1,086 seconds); AUC was 1 (p < 0.01). Specificity for all DOACs was 88%; sensitivity ranged from 72 to 100%. This diagnostic study using samples from "real-world" DOAC patients supports that ClotChip exhibits high sensitivity at detecting DOAC anticoagulant effects in a disposable portable platform, using a miniscule amount of whole blood (<10 µL).

Whole blood transfusion versus component therapy in trauma resuscitation: a systematic review and meta-analysis.

BackgroundPatients with hemorrhagic shock from trauma often require balanced blood product transfusion with red blood cells, plasma, and platelets. Resuscitation with whole blood resuscitation is becoming a common practice. We performed a systematic review and meta‐analysis of studies comparing whole blood transfusion with balanced component therapy in patients suffering from traumatic hemorrhagic shock.MethodsWe searched MEDLINE Ovid, EMBASE, and the Cochrane Library for human studies comparing whole blood with component blood therapy published from January 2007 to June 2019. We included studies from both civilian and military settings and that reported 24‐hour, in‐hospital, or 30‐day mortality. We followed the Preferred Reporting Items in Systematic Reviews and Meta‐Analyses (PRISMA) guidelines, assessing study quality, publication bias, and heterogeneity. We used meta‐analytic models to determine the associations (odds ratio [OR] with 95% confidence interval [CI]) between whole blood transfusion and (1) 24‐hour mortality, and (2) in‐hospital or 30‐day mortality.ResultsA total of 1759 identified studies, 12 (reporting on n = 8431 patients) met inclusion criteria. There was heterogeneity in the design, setting, interventions, and outcomes of the studies. On meta‐analysis, whole blood transfusion was not associated with 24‐hour mortality (OR = 0.83; 95% CI = 0.56–1.24) or in‐hospital/30‐day mortality (OR = 0.79; 95% CI = 0.48–1.31).ConclusionIn this systematic review and meta‐analysis, compared with conventional component transfusion, whole blood was not associated with 24‐hour or in‐hospital mortality. However, there were important limitations with and heterogeneity among the primary studies. Additional study is needed to determine the effectiveness of whole blood.

Marstacimab, a tissue factor pathway inhibitor neutralizing antibody, improves coagulation parameters of ex vivo dosed haemophilic blood and plasmas.

Tissue factor pathway inhibitor (TFPI) is an endogenous inhibitor of the extrinsic pathway that negatively regulates thrombin production during coagulation. Under haemophilic conditions, where the intrinsic coagulation pathway is impaired, inhibition of TFPI may improve clotting. We investigated the ex vivo effects of a human TFPI neutralizing antibody, marstacimab (previously PF-06741086), in coagulation assays including rotational thromboelastometry (ROTEM), thrombin generation assay (TGA) and the dilute prothrombin time (dPT) assay, performed in haemophilic whole blood and plasmas. We compared the effects of marstacimab to the effects of recombinant coagulation factors and investigated the reproducibility of marstacimab in restoring haemostasis by comparing its effect in whole blood collected from the same study participants on differing days. Citrated whole blood and plasmas obtained from haemophilia participants were supplemented ex vivo with vehicle, marstacimab, recombinant FVIII (rFVIII) or recombinant factor IX (rFIX) and analysed in ROTEM, TGA and the dPT assay using low tissue factor concentrations to trigger coagulation. Marstacimab induced pro-coagulant responses in ROTEM parameters including reduction in clotting times and increases in angle. Similarly, participant plasmas supplemented with marstacimab exhibited improvements in TGA parameters, including reduced lag times, increased peak thrombin concentrations and reductions in dPT clotting time. Concentrations of marstacimab tested showed activity comparable to addition of rFVIII or rFIX and were reproducible. These studies show the ex vivo potency of marstacimab in restoring haemostasis in whole blood and plasmas from haemophilia participants and comparability to ex vivo reconstitution with recombination coagulation factors.

Hemarthrosis alters mitochondrial dynamics in situ after traumatic injury

Purpose: Hemarthrosis occurs after a variety of joint injuries and contributes to rapid progression of posttraumatic osteoarthritis (PTOA). Similarly, mitochondrial responses to traumatic injury appear to modulate rate of PTOA progression. In vitro studies have shown that chondrocyte mitochondria are impaired by a variety of signaling molecules present in whole blood and that pro-inflammatory activity is responsive to manipulations of mitochondrial function. The combination of oxidizing mitochondria and oxidizing, labile iron derived from blood already associated with trauma may cause more severe mitochondrial damage in situ than previously characterized in agarose models. This study tested whether the addition of whole blood after injury would exacerbate losses in mitochondrial content observed after impact in a chelation-inhibitable fashion. Methods: Fresh, skeletally mature, bovine stifle (knee) joints were obtained from a local abattoir (Bud’s Custom Meats, Riverside, IA) and 1 cm diameter cylindrical osteochondral explants from the loaded articular surface of the femoral condyle were harvested. Explants were equilibrated for 1 day in 45% F-12/45% Dulbecco’s modified Eagle medium/10% fetal bovine serum at 37ºC with 5% O2 and 5% CO2. Explants were impacted with a 2 J impact via drop tower to the articular surface using a flat impermeable platen (or sham impact for controls) and placed into one of three solutions: normal media, normal media + 10% whole blood from the same animal, or normal media + 10% blood + the iron chelator desferrioxamine mesylate (DFO) (100 μM, Sigma-Aldrich). Samples were returned to the incubator in these solutions and 2 h later stained in serum free media with 1 μM calcein AM, a viability dye, and 200 nM MitoTracker Deep Red, a stain for mitochondria (both ThermoFisher Scientific). Cells were visualized with an Olympus FV1000 confocal microscope with a 20X objective immersed in phenol red-free media, as well as with a 100X immersion objective placed in contact with the impacted site. Images were analyzed using a custom-written two-part analysis routine developed in Matlab. Viable cells were automatically identified from the calcein AM-stained images using intensity thresholding and area-based shape measures, and resultant cell counts were expressed as viable cell density (cells/mm2). A mask image of only viable cells was applied to the MitoTracker images to extract mitochondrial staining intensity from viable cells. Data reported are the average results from explants obtained from 4 separate animals represented in all groups. Results: Impact resulted in a ∼50% reduction in viable cell density in the zone of impact across all groups and conditions. Total viable cell mitochondrial staining decreased after impact (p < 0.05) and this was not altered with whole blood addition after impact, Figure 1. A trend towards recovery of mitochondrial content was observed with whole blood and DFO after impact; however this has not reached statistical significance at n = 4 (p = 0.2 for reversing the effect of impact). A clear difference in mitochondrial network morphology was observed comparing samples with and without whole blood, Figure 2, with samples exposed to whole blood demonstrating a much more punctate, fragmented morphology. No significant differences in cell viability were observed after including blood in our studies, suggesting that impact itself was largely determinate of cell death at sites of impact. The mitochondrial phenotype after impact appears very different in the presence of hemarthrosis, with brighter and more punctate mitochondria than impact alone. Conclusions: Iron chelation may be effective in preventing loss of overall mitochondrial intensity, i.e. mitochondrial mass, but greater numbers of replicates will be needed to reach statistical significance. While DFO provided some recovery of intensity, it did not appear to rescue the morphology changes associated with exposure to blood. This study contributes to ongoing efforts in the field to improve the physiological relevance of in vitro models of cartilage injury by demonstrating a clear effect of whole blood on intracellular responses to mechanical injury.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

504: Diagnosis of pre-eclampsia: can proteinuria be attributed to hematuria?

Preeclampsia occurring prenatal or postpartum is characterized by new-onset hypertension and proteinuria. In the acute setting, urine dipstick measures of +1 proteinuria measurements correlate with protein concentrations of 30 mg/dl, meeting preeclampsia criteria. However, blood contamination of urine specimens commonly occurs and idiopathic hematuria is associated with preeclampsia, potentially invalidating measures of urine protein. We sought to quantify urine protein levels due to red blood cells (RBCs) and fresh frozen plasma (FFP) in order to determine the reliability of blood-contaminated urine protein measures. Since urine hypo- or hyperosmolarity may lyse RBCs and release intracellular protein, we further quantified the effects of urine osmolarity. Artificial urine was created using sodium chloride and ddH2O with osmolality ranging from 100 to 900 mOsm/kg. Packed RBCs and FFP were added to 10mL of saline in stepwise concentrations from 0.1 to 5% per volume, and 5 replicates of each concentration were performed. The effect of whole blood was modeled as the expected mix of RBCs and plasma (1/3, 2/3). A urine dipstick was used to measure hematuria (0, trace, +1, +2, +3) and proteinuria (0, trace, 30, 100, ≥300 mg/dl) using the Clinitek Status machine, which was automatically calibrated each use. With the addition of pRBCs, at +2 or lower hematuria levels, there was no measurable proteinuria regardless of saline osmolarity. In isotonic saline (300 mOsm/kg), at +3 hematuria (maximum reading), proteinuria levels increased as the concentration of RBCs increased, ranging from trace (0.5%) to +3 (≥3%) levels of proteinuria. The highest levels of protein were achieved in hypotonic solutions while hypertonic solutions produce slightly lower levels of protein. FFP protein levels were nearly identical to pRBCs for urine 300-900 mOsm/kg and did not vary significantly with osmolarity. In modeled whole blood, a minimum of +2 hematuria may produce +1 (30 mg/dl) proteinuria. With +2 to +3 hematuria, proteinuria measures may be falsely elevated. Therefore, at hematuria readings below +2, proteinuria should not be attributed to RBC or blood contamination. The effect of hematuria on proteinuria is heightened in hypotonic urine.

Rapid C-reactive protein determination in whole blood with a White Light Reflectance Spectroscopy label-free immunosensor for Point-of-Care applications

The fast and accurate determination of C-reactive protein (CRP) in human whole blood samples employing a white light reflectance spectroscopy sensing platform is demonstrated. Each assay cycle was completed in 12 min, including 5-min reaction with the diluted whole blood samples, 3-min with the biotinylated anti-CRP antibody, and 4-min with streptavidin solution. The effect of whole blood on the assay performance was evaluated, and it was found that dilutions as low as 50-times could be employed. Thus, taking into account that the assay had a detection limit of 2.2 μg/L CRP in 50-times diluted sample, whole blood concentrations as low as 110 μg/L could be determined. In addition, due to the implementation of a two-step sandwich immunoassay, high-dose hook-effect was avoided. The accuracy of the assay was determined through recovery experiments by spiking whole blood samples with exogenous CRP. Mean recovery values ranging from 92 to 108% were obtained, indicating the accuracy of measurements performed with the developed immunosensor. The excellent analytical characteristics, the short analysis time and the compact instrument size support the applicability of the immunosensor developed for point-of-care CRP determinations.

Effects of low-level laser irradiation on human blood lymphocytes in vitro.

Low-level laser irradiation (LLLI) has various effects on cultured human lymphocytes in vitro, but little is known about such effects in whole blood. This study investigated whether LLLI affected lymphocyte count in human whole blood in vitro. A total number of 130 blood samples were collected from apparently healthy adult patients through venipuncture into tubes containing EDTA. Each sample was divided into two equal aliquots to be used as a non-irradiated control sample and an irradiated sample. The irradiated aliquot was subjected to laser wavelengths of 405, 589, and 780nm with different fluences of 36, 54, 72, and 90J/cm2, at a fixed irradiance of 30mW/cm2. A paired student t test was used to compare between non-irradiated and irradiated samples. The lymphocyte counts were measured using a computerized hematology analyzer and showed a significant (P < 0.02) maximum increase (1.6%) at a fluence of 72J/cm2 when compared with non-irradiated samples. This increase in lymphocyte count upon irradiation was confirmed by flow cytometry. At a wavelength of 589nm and fluence of 72J/cm2, irradiation of whole blood samples showed a significant increase in CD45 lymphocytes and natural killer (NK) (CD16, CD56) cells, but no significant changes in CD3 T lymphocytes, T-suppressor (CD3, CD8) cells, T-helper (CD3, CD4) cells, and CD19 B lymphocytes when compared with their non-irradiated counterparts. Our results clearly demonstrate that NK cell count is altered by irradiation, which ultimately affects the whole lymphocyte count significantly.

Enhanced HDL Functionality in Small HDL Species Produced Upon Remodeling of HDL by Reconstituted HDL, CSL112

Rationale: CSL112, human apolipoprotein A-I (apoA-I) reconstituted with phosphatidylcholine, is known to cause a dramatic rise in small high-density lipoprotein (HDL). Objective: To explore the mechanisms by which the formation of small HDL particles is induced by CSL112. Methods and Results: Infusion of CSL112 into humans caused elevation of 2 small diameter HDL fractions and 1 large diameter fraction. Ex vivo studies showed that this remodeling does not depend on lipid transfer proteins or lipases. Rather, interaction of CSL112 with purified HDL spontaneously gave rise to 3 HDL species: a large, spherical species composed of apoA-I from native HDL and CSL112; a small, disc-shaped species composed of apoA-I from CSL112, but smaller because of the loss of phospholipids; and the smallest species, lipid-poor apoA-I composed of apoA-I from HDL and CSL112. Time-course studies suggest that remodeling occurs by an initial fusion of CSL112 with HDL and subsequent fission leading to the smaller forms. Functional studies showed that ATP-binding cassette transporter 1–dependent cholesterol efflux and anti-inflammatory effects in whole blood were carried by the 2 small species with little activity in the large species. In contrast, the ability to inactivate lipid hydroperoxides in oxidized low-density lipoprotein was carried predominantly by the 2 largest species and was low in lipid-poor apoA-I. Conclusions: We have described a mechanism for the formation of small, highly functional HDL species involving spontaneous fusion of discoidal HDL with spherical HDL and subsequent fission. Similar remodeling is likely to occur during the life cycle of apoA-I in vivo.

Protease‐activated receptor 4 is more important than protease‐activated receptor 1 for the thrombin‐induced procoagulant effect on platelets

Protease-activated receptor 4 is more important than protease-activated receptor 1 for the thrombin-induced procoagulant effect on platelets

Leukocyte filtration and postoperative infections

BackgroundLeukocyte filtration has been hypothesized to reduce the risk of postoperative infections by alleviating the immunosuppressive effect of whole blood. However, the literature regarding the clinical efficacy of leukocyte filtration remains conflicted. This meta-analysis investigates the impact of allogeneic and autologous leukocyte-filtered blood transfusions on the incidence of postoperative infections in adult surgical patients. MethodsA comprehensive literature search of PubMed, Google Scholar, and Cochrane Central Registry of Controlled trials (1966-2016) was completed for all published randomized controlled trials. Postoperative infections under “as-per-protocol” (APP) and “intention-to-treat” (ITT), length of stay, and mortality were analyzed. ResultsSixteen randomized controlled trials involving 6586 randomized (ITT) patients (4615 APP patients) in various clinical settings were evaluated. The leukocyte-filtered blood group demonstrated an overall 26% risk reduction in postoperative infections when analyzed by APP (relative risk [RR] = 0.74; 95% confidence interval [CI, 0.60-0.92]; P = 0.007) and a 22% risk reduction when analyzed by ITT (RR = 0.78; 95% CI [0.65-0.94]; P = 0.009). Leukocyte-filtered blood was also associated with a significant reduction in length of stay (standardized difference of mean [SDM] = −0.74; 95% CI [−1.32 to −0.15]; P = 0.014) and all-cause mortality (RR = 0.74; 95% CI [0.57-0.95]; P = 0.018). ConclusionsLeukocyte-filtered blood transfusions are associated with significantly lower postoperative infection rates in both the APP and ITT populations. Leukocyte filtration also shortens length of stay and decreases all-cause mortality in surgical patients and should be considered in all surgical patients.

Evaluation of the Antithrombotic Effects of Rivaroxaban and Apixaban Using the Total Thrombus-Formation Analysis System®: In Vitro and Ex Vivo Studies.

BackgroundThe usefulness of the Total Thrombus-Formation Analysis System® (T-TAS®) for monitoring the anticoagulant effects of non-vitamin K oral anticoagulants (NOACs) in clinical practice has been poorly addressed.MethodsNOACs (rivaroxaban and apixaban) were added to whole blood from healthy subjects in an in vitro study, and their effects on thrombus formation were evaluated by the T-TAS®. We also evaluated antithrombotic effects using ex vivo samples of whole blood from patients given rivaroxaban or apixaban at the respective trough and peak drug concentrations.ResultsT-TAS® could determine anticoagulant effects in whole blood treated with rivaroxaban or apixaban in vitro. The increases in the anticoagulant effects of rivaroxaban and apixaban from the trough to peak concentrations in whole blood were successfully monitored by the T-TAS® using ex vivo samples. The antithrombotic effects of rivaroxaban and apixaban (in terms of factor Xa inhibition) at the peak were strongly linked to those at the trough.ConclusionT-TAS® could be a clinically useful tool for monitoring the anticoagulant effects of factor Xa inhibitors, and may represent an accurate quantitative analysis.

Inhibitory effect of nitrite on coagulation processes demonstrated by thrombelastography

Nitric oxide (NO) can be generated by two-step reduction pathway in which nitrate is converted first into nitrite and then into NO via several mechanisms, as well as from arginine by endogenous nitric oxide synthase (NOS). We have recently shown that nitrite ions in the presence of erythrocytes inhibit platelet aggregation and activation, as measured by aggregometry and flow cytometric analysis of P-selectin, through its reduction to NO under partially deoxygenated conditions. In the current study, we investigated how nitrite may affect overall clotting processes via modulating platelet function using thrombelastography (TEG). We measured three major TEG parameters, reaction time (R, time to initial fibrin formation), α angle (velocity of clot growth) and maximum amplitude (MA, maximum clot strength) using blood from healthy volunteers. An NO donor (DEANONOate) showed inhibitory effects on all TEG parameters in platelet rich plasma (PRP) and whole blood, resulting in delayed R, decreased angle, and reduced MA in a dose dependent manner. Nitrite ions also exhibited inhibitory effects in whole blood at 20% hematocrit, and this was greatly enhanced under hypoxic conditions, being demonstrable at 0.1μM concentration. Neither compound changed any TEG parameters in plasma. Our results suggest that nitrite affects overall blood clotting and that TEG may be used to follow this process. Further the physiological effects of factors which determine NO bioavailability, such as endogenous levels of blood and tissue nitrite, may be useful as biomarkers for predicting hemostatic potential.