Red Blood Cell Ratio Research Articles

Novel lymphocyte to red blood cell ratio (LRR), neutrophil to red blood cell ratio (NRR), monocyte to red blood cell ratio (MRR) as predictive and prognostic biomarkers for locally advanced breast cancer.

Lymphocytes, neutrophils, and monocytes are vital effector cells in innate immunity. We postulated that lymphocyte to red blood cell ratio (LRR), neutrophil to red blood cell ratio (NRR), monocyte to red blood cell ratio (MRR) could represent the intensity of systemic inflammatory immunological reaction reflected through the lymphocyte, neutrophil and monocyte respectively. This study aimed to access the predictive and prognostic value of LRR, NRR, MRR and LRR-NRR-MRR score for locally advanced breast cancer. A total of 137 patients from two clinical trials SHPD002 and SHPD003 were included. Logistic regression analysis was used to evaluate the association between ratios and pathological complete response (pCR). Disease-free survival (DFS) and overall survival (OS) were estimated by Kaplan-Meier method and cox regression analysis. Lower LRR-NRR-MRR score (OR =0.593; 95% CI: 0.369-0.954; P=0.031) was more easily to achieve pCR in multivariate analysis. Lower LRR (P=0.022), NRR (P=0.027) and MRR (P=0.024) were significantly associated with better DFS. LRR-NRR-MRR score was an independently prognostic factor for both DFS (HR =3.318; 95% CI: 1.601-6.876; P=0.001) and OS (HR =3.160; 95% CI: 1.030-9.696; P=0.044). The LRR-NRR-MRR score could be identified as a new predictive biomarker for the therapeutic effect of neoadjuvant therapy and an independent prognostic factor for both DFS and OS for locally advanced breast cancer.

Fresh Frozen Plasma-to-Packed Red Blood Cell Ratio and Mortality in Traumatic Hemorrhage: Nationwide Analysis of 4,427 Patients

Despite the presence of highly reliable data, studies on packed red blood cells (pRBC):fresh frozen plasma (FFP) ratio suffer from limited sample size and the presence of survivor bias. We sought to study the association between FFP:pRBC and early mortality in the hemorrhaging trauma patient. This was a retrospective nationwide cohort that included all TQIP participating hospitals (2013 to 2016). We included all trauma patients who were transfused ≥10 pRBCs and ≥1 FFP within 24 hours. We excluded transferred patients and those who died in the emergency department or had missing/inaccurate transfusion data. Patients were assigned to 7 FFP:pRBC cohorts (range 1:1 to 1:6, and 1:6+) only if the ratio was similar at 4 and 24 hours and, to avoid survival bias, were excluded otherwise. Multivariable analyses correcting for all available confounders (age, demographics, comorbidities, vital signs, Injury Severity Score [ISS] and mechanism, procedures performed) were derived to study the independent relationship between FFP:pRBC and 24-hour mortality. Of 1,002,595 patients, 4,427 patients were included. Mean age was 41 years, 79% were males, 61% had blunt trauma, and median ISS was 29. Most patients were transfused in a 1:1, 1:2, or 1:3 ratio (31%, 41%, and 11%, respectively); mortality ranged between 28% for 1:1 and 62% for 1:4. In multivariable analyses, the odds of mortality independently and incrementally increased to 1.23 (95% CI 1.02 to 1.48) for a 1:2 ratio, 2.11 (95% CI 1.42 to 3.13) for 1:4, and as high as 4.11 (95% CI 2.31 to 7.31) for 1:5 (all p < 0.05). A 1:1 FFP:pRBC ratio is associated with the lowest mortality in the hemorrhaging trauma patient, and mortality increases with decreasing ratios.

A population-based analysis of French transfusion practices for women experiencing severe postpartum hemorrhage

BackgroundTransfusion is a major therapy for severe postpartum hemorrhage but there are few population-based descriptions of practice. The objective of this retrospective French population-based study was to describe transfusion practices in women with severe postpartum hemorrhage and the compliance with guidelines. MethodsStudy data were sourced from a prior prospective population-based study of 182 309 deliveries in France between 2012 and 2013. Transfusion practices and compliance with French national guidelines were described for all women with severe postpartum hemorrhage who had been transfused with red blood cells. ResultsIn 1495 women with severe postpartum hemorrhage (0.8% of all deliveries), 35.1% were not transfused, 50.0% were transfused during active bleeding and 14.9% exclusively after control of bleeding. Among 697 women with a hemoglobin level <7 g/dL, 21.4% were not transfused. In 747 women transfused during active bleeding, 68.8% also received fresh frozen plasma (fresh frozen plasma to red blood cell ratio between 0.5 and 1 in 80.4%). Forty-four percent received fibrinogen concentrate (including 37.4% with a plasma fibrinogen level >2 g/L) and 8.6% had a massive transfusion. Among 223 women transfused after bleeding was controlled, 5.4% received fresh frozen plasma and 13% had a hemoglobin level >7 g/dL. ConclusionsOne in five women with severe postpartum hemorrhage and a low hemoglobin concentration did not receive blood transfusion, which does not comply with French national recommendations. Over-transfusion occurred in women in whom bleeding had been controlled. The use of tools to help clinicians with transfusion decision-making should be developed.

Repeatability of regional pulmonary functional metrics of Hyperpolarized 129 Xe dissolved-phase MRI.

MRI of hyperpolarized 129 Xenon (HP 129 Xe) is increasingly utilized for investigating pulmonary function. The solubility of HP 129 Xe in lung tissue, blood plasma (Barrier), and red blood cells (RBC), with unique chemical shifts, enables spectroscopic imaging of potential imaging biomarkers of gas exchange and microstructural pulmonary physiology. To quantify global average and regional repeatability of Barrier:gas, RBC:gas, and RBC:Barrier ratios derived from dissolved-phase 129 Xe imaging and their dependence on intervisit changes in lung inflation volume. Prospective. Fourteen healthy volunteers. One subject was unable to complete the study resulting in 13 subjects for analysis (eight female, five male, ages 24-69, 53.8 ± 13.9). 1.5T. Subjects were imaged using a 3D radial 1-point Dixon method to separate Barrier and RBC component signals, at two different timepoints, with ~1 month between visits. RBC:Gas, Barrier:Gas, and RBC:Barrier measures were compared across time and with pulmonary function tests (PFTs). Repeatablilty was quantified using Bland-Altman plots, coefficient of repeatability, coefficient of variation (CV), and intraclass correlation coefficients (ICCs). Dependence of imaging measures on PFTs and lung volume was evaluated using Spearman and Pearson correlation coefficients, respectively. Statistical significance was determined by F-test for intraclass correlations, and t-test for Spearman correlations and regression. Mean RBC:Gas, Barrier:Gas, and RBC:Barrier had CVs of 19.2%, 20.0%, and 11.5%, respectively, and had significant ICCs, equal to 0.78, 0.79, and 0.92, respectively. Intervisit differences in RBC:Barrier were significantly correlated with intervisit differences in DLCO (r = 0.93, P = 0.007). Significant correlations with intervisit lung volume differences and intervisit differences in mean RBC:Gas (r = -0.73, P = 0.005) and Barrier:Gas (r = -0.69, P = 0.009) were found. Three commonly used 129 Xe MRI-based measures of gas-exchange show good repeatability, particularly the Barrier:RBC ratio, which did not depend on lung inflation volume and was strongly associated with intervisit changes in DLCO . 1 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2019;50:1182-1190.

Hematologic disorders during essential hypertension

BackgroundBesides the traditional risk factors, hematological changes may be involved in the development of arterial hypertension and in its pathogenesis. MethodsThe study, conducted on a sample of 545 subjects, 215 with hypertension and 330 witnesses, were evaluated for peripheral blood parameters in western Algeria; Logistic regression analysis was used to predict hypertension with hematological parameters. ResultsThe characters studied related significantly; lower red blood cell levels have a three-and-a-half-fold risk of developing hypertension compared to those who have normal red blood cell counts (OR = 3.64, 95% CI = 1.37–9.65, p < 0.05). Subjects who have mean corpuscular volume rate below 80 fl are more exposed to hypertension (OR = 13.58, 95% CI = 4.68–39.41, p = 0.000). The mean corpuscular hemoglobin concentration reveals that subjects who have a lower than normal (<27 pg) are once less exposed to hypertension (OR = 0.04, 95% CI = 0.01–0.13, p = 0.000). Subjects who have lower platelet count than normal are twelve times more exposed to hypertension (OR = 12.13, 95% CI = 1.45–101.18, P = 0.021). Finally, the increase in sedimentation rate at one hour increases the risk of hypertension by 56.63 times compared to subjects with normal sedimentation rate (OR = 56.63, 95% CI = 3.37–597.33, P = 0.001). ConclusionsHematological profile associated with essential hypertension retained Red blood cells ratio, mean corpuscular volume, mean corpuscular hemoglobin concentration, platelet ratio, and sedimentation rate at one hour.

Erythrocyte-cancer hybrid membrane-camouflaged melanin nanoparticles for enhancing photothermal therapy efficacy in tumors

Cell membrane coating has emerged as an intriguing biomimetic strategy to endow nanomaterials with functions and properties inherent to source cells for various biomedical applications. Hybrid membrane of different types of cells could be coated onto nanoparticle surface to achieve additional functions. Herein, we fused red blood cell (RBC) membrane together with MCF-7 cell membrane and fabricated an erythrocyte-cancer (RBC-M) hybrid membrane-camouflaged melanin nanoparticle (Melanin@RBC-M) platform for enhancing therapeutic efficacy of photothermal therapy (PTT). The fused RBC-M hybrid membrane vesicles retained both RBC and MCF-7 cell membrane proteins and the resultant Melanin@RBC-M exhibited prolonged blood circulation and homotypic targeting to source MCF-7 cells simultaneously. Interestingly, increasing MCF-7 membrane components in RBC-M significantly enhanced the homotypic targeting function of Melanin@RBC-M while increasing RBC membrane components in RBC-M effectively reduced the cellular uptake of Melanin@RBC-M by macrophages and improved their circulation time in the blood. After intravenous injection into MCF-7 tumor-bearing athymic nude mice, Melanin@RBC-M with 1:1 membrane protein weight ratio of RBC to MCF-7 exhibited significantly higher tumor accumulation and better PTT efficacy compared with other Melanin@RBC-M with different membrane protein weight ratios as well as pristine melanin nanoparticles, due to the optimal balance between prolonged blood circulation and homotypic targeting. In addition, in vitro photoacoustic results revealed that Melanin@RBC-M had a photoacoustic signal enhancement with the increase of nanoparticle size (64 → 148 nm) and the photoacoustic amplitudes increased linearly with nanoparticle concentration at the excitation wavelength ranged from 680 nm to 800 nm, which could be used for quantification of Melanin@RBC-M in vivo. Looking forward, coating hybrid membrane onto nanoparticles could add flexibility and controllability in enhancing nanoparticles functionality and offer new opportunities for biomedical applications.

Care Standardization Reduces Blood Donor Exposures and Transfusion in Complex Cranial Vault Reconstruction.

Complex cranial vault reconstruction (CCVR) often requires a large-volume transfusion of blood products. We implemented a series of improvement interventions to reduce blood donor exposures (BDE) and transfusion requirements in CCVR. We implemented interventions over 4 epochs: (E1) reconstituted blood (1:1 ratio of donor-matched red blood cells and fresh-frozen plasma) for intraoperative transfusions, (E2) reconstituted blood plus postoperative transfusion guidelines, (E3) reconstituted blood plus intraoperative antifibrinolytics and postoperative guidelines, and (E4) fresh whole blood for intraoperative transfusion, antifibrinolytics, and postoperative guidelines. Primary outcomes, BDE, and total volume of blood products transfused are presented by using statistical process control charts, with statistical comparisons between each epoch and baseline data. We included 347 patients <72 months old who underwent CCVR between 2008 and 2016 (E1: n = 50; E2: n = 41; E3: n = 87; and E4: n = 169). They were compared with a baseline sample group of 138 patients who were managed between 2001 and 2006. Compared with our baseline group, patients in each epoch had a significant reduction in BDE (P = .02-<.0001). Conversely, compared with the baseline group, we observed an increase the volume of blood products transfused in E1 (P = .004), no difference in E2 (P = .6) or E3 (P = .46), and a reduction in the volume of blood products transfused in E4 (P < .0001). The implementation of sequential clinical improvement strategies resulted in a sustained reduction in BDE whereas only the use of whole blood resulted in a significant reduction in the total volume of blood products transfused in children undergoing CCVR.

Estimation of platelet counts: auto analyzer versus counts from peripheral blood smear based on traditional and platelet: red blood cell ratio method

Introduction: Accurate platelet counts are of utmost importance in clinical practice The methods used for estimating platelet count are: Manual method using counting chamber, Examination of a peripheral blood smear (PBS) and automated hematology analyzers Automated hematology analyzers produce erroneous results in the presence of particles of similar size and/or light scatter like fragmented red blood cells (RBC), microcytic RBCs and in the presence of giant platelets and platelet clumps. Aims and Objectives: Comparison of platelet count by three methods: 1. Automated six part analyzer. Traditional method: Counting average platelets per ten high power fields and multiplying the same by 15,000. 3. From smear by counting the number of platelets per 1000 RBCs and calculating the platelet count on the basis of platelet: RBC ratio. Methods: Ethylene Diamine Tetra-acetic acid (EDTA) samples for platelet counts over a period of two months were analyzed by the above-mentioned methods. Statistical software SPSS 2 and independent T tests were used to compare the variables between the groups. Sensitivity and specificity of the methods was calculated. Results: 250 EDTA samples were analyzed of which normal platelet counts were (56.4%) thrombocytopenic (35.2%) and thrombocytosis (8.4%). There was no significant difference between the platelet counts done by the auto analyzer compared with traditional (P value 0.50) and platelet: RBC ratio method (0.906). Specificity of the methods was 99.1% and the sensitivity was 92.5%. Conclusion: Platelet counts by traditional and platelet: RBC ratio can be used as alternate reliable methods as compared to the auto analyzers.

Effect of Different Sources of Supplemental Zinc on Performance, Nutrient Digestibility, and Antioxidant Enzyme Activities in Lambs.

Zinc (Zn) is an essential element in the growth of all animals and plays structural and catalytic roles in many enzymes and functional proteins. Two completely randomized trials were conducted to evaluate the effects of different sources of zinc on performance, nutrient digestibility, blood mineral profile, and antioxidant enzyme activities in male growing lambs on a barley-based diet. The first trial was conducted for 70days and consisted of 30 lambs (30.8 ± 2.8kg mean body weight, 4-5months of age) which were randomly allocated to five treatments consisting of a basal diet (19.72mg Zn/kg DM), or the basal diet supplemented with 30mg Zn/kg DM, added as either zinc-sulfate (ZnSulf; inorganic), zinc-methionine (ZnMet), zinc-proteinate (ZnProt) or zinc-glycinate (ZnGly). For the second trial, to measure the effects of dietary Zn on nutrient digestibility, four lambs from each group of the first experiment were randomly allocated to individual digestibility cages for 12days (first 7days as an adaptation period followed by 5days of sample collection). Among the groups, dietary Zn supplementation above basal level significantly improved average daily gain, average daily feed intake, feed/gain ratio, and superoxide dismutase activity of red blood cells (P < 0.05). Glutathione peroxidase activity of lambs supplemented with organic Zn was significantly (P < 0.05) higher than inorganic and control groups. At the end of the trial, the concentration of plasma Zn, tri-iodothyronine (T3), thyroxine (T4), and the activity of alkaline phosphatase was increased (P < 0.05) in all groups receiving Zn as compared with controls (P < 0.05). In addition, thyroxine level in animals supplemented with Zn-methionine and Zn-proteinate was greater than in animals receiving Zn-glycine and Zn-sulfate. The results of the second trial revealed that the supplementation with Zn-methionine and Zn-proteinate increased the digestibility of crude protein (CP) and acid detergent fiber (ADF) compared to groups supplemented with Zn sulfate and control (P < 0.05). All organic sources of Zn improved organic matter (OM) digestibility compared to inorganic and control (P < 0.05). Results indicated that, regardless of source, supplementation of Zn in growing lambs improved growth performance, blood antioxidants, and thyroid hormone levels. Furthermore, Zn-methionine and Zn-proteinate supplementation appeared to improve the digestibility of CP, OM, and ADF more effectively than Zn-sulfate.

Outcomes of patients receiving a massive transfusion for major trauma.

The benefits of high transfusion ratios (plasma to red blood cells and platelets to red blood cells) on survival in injured patients who receive massive transfusions remain uncertain. This study aimed to assess the association between transfusion ratios and adverse events and survival in patients undergoing massive transfusion for major trauma. A retrospective observational study was conducted on patients who had major trauma using a Japanese national administrative database. The associations between transfusion ratios and outcomes (in-hospital mortality and incidence of adverse events) were analysed using a non-linear logistic generalized additive model (GAM). In a logistic generalized estimating equation model, adjusted for patient and hospital-level confounders, transfusion ratios were included as continuous or categorical variables (low, transfusion ratio 0·75 or less; intermediate, over 0·75 to 1·25; high, over 1·25). Some 1777 patients were included in the analysis, of whom 602 died in hospital. GAM plots of the transfusion ratios for in-hospital mortality demonstrated a downward convex unimodal curve. In-hospital mortality was similar with increasing transfusion ratios for plasma (adjusted odds ratio (OR) 1·13, 95 per cent c.i. 0·82 to 1·55; P = 0·446) and platelets (adjusted OR 0·84, 0·66 to 1·08; P = 0·171). Both plasma to red blood cell ratio (adjusted OR 1·77, 1·32 to 2·37; P < 0·001) and platelet to red blood cell ratio (adjusted OR 1·71, 1·35 to 2·15; P < 0·001) were significantly associated with a higher incidence of adverse events. No significant differences in in-hospital mortality were observed between the three transfusion categories (low, medium and high). In this study, transfusion strategies with high plasma to red blood cell and platelet to red blood cell ratios did not have survival benefits, but were associated with an increase in adverse events.

Removal of hyperpolarized 129 Xe gas-phase contamination in spectroscopic imaging of the lungs.

A novel technique is presented for retrospective estimation and removal of gas-phase hyperpolarized Xenon-129 (HP 129 Xe) from images of HP 129 Xe dissolved in the barrier (comprised of parenchymal lung tissue and blood plasma) and red blood cell (RBC) phases. The primary aim is mitigating RF pulse performance limitations on measures of gas exchange (e.g., barrier-gas and RBC-gas ratios). Correction for gas contamination would simplify technical dissemination of HP 129 Xe applications across sites with varying hardware performance, scanner vendors, and models. Digital lung phantom and human subject experiments (N = 8 healthy; N = 1 with idiopathic pulmonary fibrosis) were acquired with 3D radial trajectory and 1-point Dixon spectroscopic imaging to assess the correction method for mitigating barrier and RBC imaging artifacts. Dependence of performance on TE, image SNR, and gas contamination level were characterized. Inter- and intra-subject variation in the dissolved-phase ratios were quantified and compared to human subject experiments before and after correction. Gas contamination resulted in image artifacts similar to those in disease that were mitigated after correction in both simulated and human subject data; for simulation experiments performance varied with TE, but was independent of image SNR and the amount of gas contamination. Artifacts and variation of barrier and RBC components were reduced after correction in both simulation and healthy human lungs (barrier, P = 0.01; RBC, P = 0.045). The proposed technique significantly reduced regional variations in barrier and RBC ratios, separated using a 1-point Dixon approach, with improved accuracy of dissolved-phase HP 129 Xe images confirmed in simulation experiments.

Fluorescence Exclusion: A Simple Method to Assess Projected Surface, Volume and Morphology of Red Blood Cells Stored in Blood Bank.

Red blood cells (RBC) ability to circulate is closely related to their surface area-to-volume ratio. A decrease in this ratio induces a decrease in RBC deformability that can lead to their retention and elimination in the spleen. We recently showed that a subpopulation of “small RBC” with reduced projected surface area accumulated upon storage in blood bank concentrates, but data on the volume of these altered RBC are lacking. So far, single cell measurement of RBC volume has remained a challenging task achieved by a few sophisticated methods some being subject to potential artifacts. We aimed to develop a reproducible and ergonomic method to assess simultaneously RBC volume and morphology at the single cell level. We adapted the fluorescence exclusion measurement of volume in nucleated cells to the measurement of RBC volume. This method requires no pre-treatment of the cell and can be performed in physiological or experimental buffer. In addition to RBC volume assessment, brightfield images enabling a precise definition of the morphology and the measurement of projected surface area can be generated simultaneously. We first verified that fluorescence exclusion is precise, reproducible and can quantify volume modifications following morphological changes induced by heating or incubation in non-physiological medium. We then used the method to characterize RBC stored for 42 days in SAG-M in blood bank conditions. Simultaneous determination of the volume, projected surface area and morphology allowed to evaluate the surface area-to-volume ratio of individual RBC upon storage. We observed a similar surface area-to-volume ratio in discocytes (D) and echinocytes I (EI), which decreased in EII (7%) and EIII (24%), sphero-echinocytes (SE; 41%) and spherocytes (S; 47%). If RBC dimensions determine indeed the ability of RBC to cross the spleen, these modifications are expected to induce the rapid splenic entrapment of the most morphologically altered RBC (EIII, SE, and S) and further support the hypothesis of a rapid clearance of the “small RBC” subpopulation by the spleen following transfusion.

Use of French lyophilized plasma transfusion in severe trauma patients is associated with an early plasma transfusion and early transfusion ratio improvement.

Early transfusion of high ratio of fresh frozen plasma (FFP) and red blood cells (RBC) is associated with mortality reduction. However, time to reach high ratio is limited by the need to thaw the FFP. French lyophilized plasma (FLYP) used by French army and available in military teaching hospital does not need to be thawed and is immediately available. We hypothesize that the use of FLYP may reduce time to reach a plasma/RBC ratio of 1:1. A retrospective study performed in a Level 1 trauma center between January 2012 and December 2015. Severe trauma patients who received 2 U of RBC in the emergency room were included and assigned to two groups according to first plasma transfused: FLYP group and FFP group. Forty-three severe trauma patients in the FLYP group and 29 in the FFP group were included. The time until first plasma transfusion was shorter in the FLYP group than in the FFP group, respectively 15 min (10-25) versus 95 min (70-145) (p < 0.0001). Time until a 1:1 ratio was shorter in the FLYP group than in the FFP group. There were significantly fewer cases of massive transfusion in the FLYP group than in the FFP group with respectively 7% vs. 45% (p < 0.0001). The use of FLYP provided significantly faster plasma transfusions than the use of FFP as well as a plasma and RBC ratio superior to 1:2 that was reached more rapidly in severe trauma patients. These results may explain the less frequent need for massive transfusion in the patients who received FLYP. These positive results should be confirmed by a prospective and randomized evaluation. Therapeutic, level IV.

A genome-wide association study of red-blood cell fatty acids and ratios incorporating dietary covariates: Framingham Heart Study Offspring Cohort.

Recent analyses have suggested a strong heritable component to circulating fatty acid (FA) levels; however, only a limited number of genes have been identified which associate with FA levels. In order to expand upon a previous genome wide association study done on participants in the Framingham Heart Study Offspring Cohort and FA levels, we used data from 2,400 of these individuals for whom red blood cell FA profiles, dietary information and genotypes are available, and then conducted a genome-wide evaluation of potential genetic variants associated with 22 FAs and 15 FA ratios, after adjusting for relevant dietary covariates. Our analysis found nine previously identified loci associated with FA levels (FADS, ELOVL2, PCOLCE2, LPCAT3, AGPAT4, NTAN1/PDXDC1, PKD2L1, HBS1L/MYB and RAB3GAP1/MCM6), while identifying four novel loci. The latter include an association between variants in CALN1 (Chromosome 7) and eicosapentaenoic acid (EPA), DHRS4L2 (Chromosome 14) and a FA ratio measuring delta-9-desaturase activity, as well as two loci associated with less well understood proteins. Thus, the inclusion of dietary covariates had a modest impact, helping to uncover four additional loci. While genome-wide association studies continue to uncover additional genes associated with circulating FA levels, much of the heritable risk is yet to be explained, suggesting the potential role of rare genetic variation, epistasis and gene-environment interactions on FA levels as well. Further studies are needed to continue to understand the complex genetic picture of FA metabolism and synthesis.

Patient-Specific Adhesion of Sickle Red Blood Cells in Shear-Gradient Microscale Flow

The pathophysiology of sickle cell disease (SCD) involves altered biophysical properties of red blood cells (RBCs) and increased cellular adhesion, which can synergistically trigger recurrent and painful vaso-occlusive events in the microcirculatory network. RBC adhesion to the endothelial wall is heterogeneous and may initiate such occlusions by disrupting the local flow thus activating platelets and promoting subsequent cell-cell interactions. Moreover, these episodic events take place within a wide range of dynamically changing shear rates at the microscale. In order to better understand the role of shear rate on this process, we quantified shear-dependent RBC adhesion to endothelial proteins fibronectin (FN) and laminin (LN) utilizing a microfluidic system that can simulate physiologically relevant shear gradients of microcirculatory blood flow at a single flow rate.Whole blood samples were collected from 20 patients (10 males and 10 females) with homozygous SCD (HbSS). Samples were perfused through FN and LN immobilized shear-gradient microchannels (Fig. 1A) in which the shear rate continuously changes along flow direction. Computational simulations characterized the flow dynamics near the adherent RBCs (Fig. 1B). Based on the numerical results, a rectangular “field of interest (FOI)”, along which the shear rate dropped approximately three-fold, was chosen for quantification of shear-dependent RBC adhesion.We observed changes in RBC adhesion to LN and FN in the shear gradient flow. Figure 1C and 1D show typical adhesion curves of surface adherent RBCs for an individual SCD sample within the FOI. To assess patient specific shear-dependent adhesion, we defined a parameter, “shear dependent adhesion rate (SDAR)”, which is the slope of the adhesion curves based on normalized RBC adhesion numbers.A higher SDAR value was indicative of marked numbers of adherent RBCs that detach at higher shear rates whereas the effect of shear rate on RBC detachment was less for a lower SDAR. We observed an inverse relationship between SDAR and number of persistently adherent RBCs at high shear rates. Shear-dependent RBC adhesion to LN was heterogeneous among SCD patients. Patients with higher WBC counts constituted the low SDAR population with a threshold SDAR value of 60 (Fig. 1E, p=0.005, ANOVA). WBCs from patients with higher SDARs (and fewer persistently adhered cells) were all within the normal range. Patients in the low SDAR group also had significantly elevated absolute neutrophil counts (Fig. 1F, p=0.006, ANOVA), and ferritin levels (Fig. 1G, p=0.007, ANOVA). The mean ferritin level of those with low SDAR was nearly ten times greater than normal (mean= [3272.3 ± 791.9] μg/L vs. [784.5±219.6] μg/L). No white blood cell (WBC) adhesion was observed in the experiments.Here, we report a novel shear dependent adhesion ratio of sickle RBCs utilizing LN and FN functionalized microchannels. The approach presented here enabled us to create a shear gradient throughout the channel which may simulate the physiological flow conditions in the post-capillary venules. We further analyzed shear-dependent RBC adhesion in a patient specific manner and identified patient groups with low and high SDAR. The findings also suggested a link between lower shear dependent sickle RBC adhesion to LN and patient clinical phenotypes including inflammation and iron overload.Acknowledgments: This work was supported by grant #2013126 from the Doris Duke Charitable Foundation, National Heart Lung and Blood Institute R01HL133574, and National Science Foundation CAREER Award 1552782.Figure 1: Shear-dependent sickle RBC adhesion in microscale flow. (A) Macroscopic image of the shear-gradient microchannel with the arrow indicating flow direction. (B) Velocity and shear rate contours on a 2D plane above the bottom surface. The dashed rectangular area indicates the field of interest (FOI) where the experimental data were obtained. (C, D) Typical distribution of adherent deformable and non-deformable RBCs in LN and FN functionalized microchannels with the shear gradient. Dashed lines represent the adhesion curves and the corresponding equations were used to quantify shear dependent adhesion data. Shear-dependent RBC adhesion was lower (nSDAR<60) in patients with elevated white blood cell counts (E), absolute neutrophil counts (F), and serum ferritin levels (G). The dashed rectangles indicate the normal clinical values. [Display omitted] DisclosuresLittle:Hemex Health: Equity Ownership. Gurkan:Hemex Health: Employment, Equity Ownership.

Risk factors for fetomaternal bleeding after laser therapy for twin-twin transfusion syndrome.

To quantify and assess potential risk factors for transplacental passage of fetal red blood cells (RBCs) into the maternal circulation (fetomaternal bleeding, FMB) after laser surgery for twin-twin transfusion syndrome (TTTS). A retrospective study of Rhesus-D negative patients that underwent laser surgery for TTTS. Patients with and without postoperative detectable fetal RBCs on Kleihauer-Betke (KB) testing were compared to determine risk factors for FMB. Patients were further sub-classified into those with a FMB<20% and ≥20% of estimated fetoplacental blood volume. Of 60 studied patients, 26/60 (43%) had a positive postoperative KB test. The median fetal:adult RBC ratio was 0.00125, estimated to be a FMB volume of 6.25mL. There were 17/26 (65%) of patients with FMB<20% and 9/26 (35%) patients with ≥20% of the fetoplacental blood volume. Stage III-Recipient and III-Recipient/Donor patients were more likely to have a positive KB test (14/21 [66.7%] vs 12/39 [30.8%], OR=4.50 [1.27-16.54], P=0.0162). No other risk factors for FMB were apparent. Fetomaternal bleed appears to be a common finding after laser surgery for TTTS. TTTS Stage, particularly stage III-Recipient and III-Recipient/Donor, appears to be a risk factor for FMB.

Optimal Dose, Timing and Ratio of Blood Products in Massive Transfusion: Results from a Systematic Review

Optimal dose, timing and ratio to red blood cells (RBC) of blood component therapy (fresh frozen plasma [FFP], platelets, cryoprecipitate or fibrinogen concentrate) to reduce morbidity and mortality in critically bleeding patients requiring massive transfusion is unknown. We performed a systematic review for randomized controlled trials (RCT) in MEDLINE, The Cochrane Library, Embase, CINAHL, PubMed the Transfusion Evidence Library and using multiple clinical trials registries to 21 February 2017. Sixteen RCTs were identified: six completed (five in adult trauma patients, one pediatric burn patients) and ten ongoing trials. Of the completed trials: three were feasibility trials, comparing a FFP, platelets and RBC ratio of 1:1:1 to laboratory-guided transfusion practice [n=69], early cryoprecipitate compared to standard practice [n=41], and early fibrinogen concentrate compared to placebo [n=45]; one trial compared the effect of FFP, platelets and RBC ratio of 1:1:1 with 1:1:2 on 24-hour and 30-day mortality [n=680]; one compared whole blood to blood component therapy on 24-hour blood use [n=107]; one compared a FFP to RBC ratio of 1:1 with 1:4 [n=16]. Data from two trials were pooled in a meta-analysis for 28-day mortality because the transfusion ratios achieved were similar. Results from these two trials suggest higher transfusion ratios were associated with transfusion of more FFP and platelets without evidence of significant difference with respect to mortality or morbidity. On the limited evidence available, there is insufficient basis to recommend a 1:1:1 over a 1:1:2 ratio or standard care for adult patients with critical bleeding requiring massive transfusion.

Application of fresh whole blood for resuscitation with massive blood loss

First transfusion of fresh whole blood happened more than 100 years ago. But, after that, transfusion of blood components became more common. Among them are: red blood cells (RBC), fresh frozen plasma (FFP), platelets, cryoprecipitate. One of the major issues in massive transfusion is a trauma-related coagulopathy. For its prophylaxis and treatment, an 1:1:1 ratio of RBC:FFP:platelets during massive transfusion is advised. But, this goal is often unachievable during to lack of blood components readily available and, moreover, this ratio is close to composition of fresh whole blood. Also, there is an opinion, that switch to blood component-based therapy is not always feasible and fresh whole blood can be much more effective than blood components for treatment of trauma-induced coagulopathy. Indications for, benefits and disadvantages of fresh whole blood are within scope of this review.

Dietary and genetic influences on hemostasis in a Yup'ik Alaska Native population.

Fish and marine animals are important components of the subsistence diet of Alaska Native people, resulting in a high ω3 PUFA intake. The historical record for circumpolar populations highlights a tendency for facile bleeding, possibly related to ω3 PUFA effects on platelet activation and/or vitamin K-dependent clotting factors. To evaluate these two scenarios in Yup’ik people of southwestern Alaska, we examined the association between dietary ω3 PUFA intake and activities of clotting factor II, V, fibrinogen, PT, INR, PTT, and sP-selectin in 733 study participants, using the nitrogen isotope ratio of red blood cells as a biomarker of ω3 PUFA consumption. sP-selectin alone correlated strongly and inversely with ω3 PUFA consumption. Approximately 36% of study participants exhibited PIVKA-II values above the threshold of 2 ng/ml, indicative of low vitamin K status. To assess genetic influences on vitamin K status, study participants were genotyped for common vitamin K cycle polymorphisms in VKORC1, GGCX and CYP4F2. Only CYP4F2*3 associated significantly with vitamin K status, for both acute (plasma vitamin K) and long-term (PIVKA-II) measures. These findings suggest: (i) a primary association of ω3 PUFAs on platelet activation, as opposed to vitamin K-dependent clotting factor activity, (ii) that reduced CYP4F2 enzyme activity associates with vitamin K status. We conclude that high ω3 PUFA intake promotes an anti-platelet effect and speculate that the high frequency of the CYP4F2*3 allele in Yup’ik people (~45%) evolved in response to a need to conserve body stores of vitamin K due to environmental limitations on its availability.

Association Between Ratio of Fresh Frozen Plasma to Red Blood Cells During Massive Transfusion and Survival Among Patients Without Traumatic Injury

Hemostatic resuscitation has been shown to be beneficial for patients with trauma, but there is little evidence that it is equally beneficial for bleeding patients without trauma. The practice of a high transfusion ratio of fresh frozen plasma (FFP) to red blood cells (RBCs) has spread to other surgical and medical fields. To identify whether ratio-based resuscitation in patients without trauma is associated with improved survival. This study is a retrospective review of all massive transfusions provided in an urban academic hospital from January 1, 2009, through December 31, 2012. Massive transfusion was defined as the transfusion of at least 10 U of RBCs in the first 24 hours after a patient's admission to the operating room, emergency department, or intensive care unit. All patients who received massive transfusions within the study period and survived more than 30 minutes after hospital arrival were counted (n=865). Patients were grouped into those with trauma and those without trauma. Sources of data included the Research Patient Data Registry, patients' medical records, and blood bank records. All data collection occurred between April 26, 2013, and April 26, 2015. Data analysis took place from April 27, 2015, and June 22, 2016. Examination of FFP:RBC transfusion ratios for patients without trauma. There were 865 massive transfusion events that occurred within 4 years, transfusing 16 569 U of RBCs, 13 933 U of FFP, 5228 U of cryoprecipitate, and 22 635 U of platelets. Most of these transfusions were received by patients without trauma (767 [88.7%]), by men (582 [67.3%]), and for intraoperative bleeding (544 [62.9%]). The FFP:RBC ratios of survivors and nonsurvivors were nearly identical: the ratio for survivors was 1:1.5 (interquartile range [IQR], 1:1.1-1:2.2) and for nonsurvivors was 1:1.4 (IQR, 1:1.1-1:1.9; P = .43). Among the 767 patients without trauma, there was no difference in the adjusted odds ratio (aOR) for 30-day mortality when comparing the high FFP:RBC ratio vs the low FFP:RBC ratio subgroups (aOR, 1.10; 95% CI, 0.72-1.70; P = .65). In vascular surgery, the aOR for death favored the high FFP:RBC ratio subgroup (aOR, 0.16; 95% CI, 0.03-0.79; P = .02). However, in general surgery and medicine, the aOR for death favored the low FFP:RBC ratio subgroup; general surgery: aOR, 4.27 (95% CI, 1.28-14.22; P = .02); medicine: aOR, 8.48 (95% CI, 1.50-47.75; P = .02). High FFP:RBC transfusion ratios are applied mostly to patients without trauma, who account for nearly 90% of all massive transfusion events. Thirty-day survival was not significantly different in patients who received a high FFP:RBC ratio compared with those who received a low ratio.