Red cell transfusion and the immune system

The treatment of chronic anemia in heart failure: a global approach

Chronic anemia is an independent risk factor for mortality in patients with heart failure (HF). Restoring physiological hemoglobin (Hb) levels is essential to increase oxygen transport capacity to tissues and improve cell metabolism as well as physical and cardiac performance. Nutritional deficits and iron deficiency are the major causes of chronic anemia, but other etiologies include chronic kidney disease, inflammatory processes, and unexplained anemia. Hormonal therapy, including erythropoietin (EPO) and anabolic treatment in chronic anemia HF patients, may contribute to improving Hb levels and clinical outcomes. Although preliminary studies showed a beneficial effect of EPO therapy on cardiac efficiency and in HF, more recent studies have not confirmed this positive impact of EPO, alluding to its side effect profile. Physical exercise significantly increases Hb levels and the response of anemia to treatment. In malnourished patients and chronic inflammatory processes, low levels of anabolic hormones, such as testosterone and insulin-like growth factor-1, contribute to the development of chronic anemia. This paper aims to review the effect of nutrition, EPO, anabolic hormones, standard HF treatments, and exercise as regulatory mechanisms of chronic anemia and their cardiovascular consequences in patients with HF.

Impact of a cell salvage device on blood transfusions to dogs undergoing surgery at a referral veterinary hospital

OBJECTIVE

To determine the number of homologous blood transfusions received by canine surgical patients after introducing a cell salvage device (CSD), trends in surgeries requiring blood transfusion, and the incidence of transfusion reactions.

STUDY DESIGN

Retrospective study.

SETTING

Single referral hospital.

ANIMALS

All dogs having surgery at a single center (November 2015 to February 2021).

INTERVENTIONS

Medical records of dogs having surgical treatment, including those that received either an autologous or homologous blood transfusion, were reviewed. The surgical patients were the baseline population, and the 2 transfusion groups were compared within this population to analyze the trends.

MAIN RESULTS

A total of 37 and 86 dogs received autologous and homologous blood transfusions, respectively. There was an upward trend in the number of total monthly blood transfusions. No significant increase in the monthly number of homologous transfusions was observed before or after acquisition of the CSD. There was also an upward trend in total monthly surgeries, including those with higher risks of hemorrhage. Dogs receiving homologous blood transfusions had a higher incidence of clinical signs consistent with transfusion reactions (6.98%).

CONCLUSIONS

An upward trend in autologous blood transfusions was seen with the introduction of a CSD. Hospitals with large surgical caseloads at high risk of hemorrhage may see a decreased need for outsourced blood products with the use of the CSD. The device can lead to a more responsible use of an increasingly scarce resource and decrease the risk of a blood transfusion reaction in dogs.

Feasibility and performance of in-house red blood cell reagents to detect unexpected antibodies in immunized patients in Burkina Faso

In sub-Saharan Africa, antibody detection tests remain inaccessible because of the high cost and limited shelf life of red blood cell (RBC) reagents. This study aimed at investigating the feasibility and performance of locally prepared RBC reagents for antibody detection in Burkina Faso. We conducted an experimental study comparing commercial RBC panels and a local panel prepared from phenotyped blood donors in Ouagadougou, Burkina Faso. Antibody detection testing was performed by the indirect antiglobulin test using a gel card filtration column in a low-ionic-strength solution. Judgment criteria were the concordance rate and the kappa agreement coefficient of results generated by the two panels. A total of 302 blood donors were phenotyped for the major antigens of the RH, KEL, MNS, FY, JK, LE, and P1PK blood group systems. From this pool of donors, we designed an RBC detection panel that was used to screen for unexpected antibodies in 1096 plasma samples from 832 patients with a history of transfusion and 264 recently delivered or pregnant women with no history of blood transfusion. A positive antibody detection test was observed in 8.1 percent of the samples using the local panel versus 6.4 percent with the commercial panels. A total of 23 samples were negative with the commercial panels and positive with the local panel, while the findings were reversed for four samples. The concordance rate was 97.5 percent, and the kappa agreement coefficient was 0.815. Our results suggest that the development of local RBC panels can be an alternative to commercial panels in countries with limited resources. It could also be a cost-effective intervention, mainly for children under 5 years of age, women of childbearing age, and pregnant women, all of whom are most at risk for malaria and sickle cell disease complications. Blood services could develop and implement appropriate strategies to make phenotyped donor pools available for the design of suitable RBC panels.

Patient Blood Management in Microsurgical Procedures for Reconstructive Surgery

Introduction: The main purpose of reconstructive surgery (RS) is to restore the integrity of soft tissues damaged by trauma, surgery, congenital deformity, burns, or infection. Microsurgical techniques consist of harvesting tissues that are separated from the vascular sources of the donor site and anastomosed to the vessels of the recipient site. In these procedures, there are some preoperative modifiable factors that have the potential to influence the outcome of the flap transfer and its anastomosis. The management of anemia, which is always present in the postoperative period and plays a decisive role in the implantation of the flap, covers significant importance, and is associated with clinical and laboratory settings of chronic inflammation. Methods: Chronic inflammatory anemia (ACD) is a constant condition in patients who have undergone RS and correlates with the perfusion of the free flap. The aim of this treatment protocol is to reduce the transfusion rate by maintaining both a good organ perfusion and correction of the patient's anemic state. From January 2017 to September 2019, we studied 16 patients (16 males, mean age 38 years) who underwent microsurgical procedures for RS. Their hemoglobin (Hb) levels, corpuscular indexes, transferrin saturation (TSAT) ferritin concentrations and creatinine clearance were measured the first day after surgery (T0), after the first week (T1), and after five weeks (T2). At T0, all the patients showed low hemoglobin levels (average 7.4 g/dL, STD 0.71 range 6.2-7.4 g dL-1), with an MCV of 72, MCH of 28, MCHC of 33, RDW of 16, serum iron of 35, ferritin of 28, Ret% of 1.36, TRF of 277, creatinine clearance of 119 and high ferritin levels (range 320-560 ng mL-1) with TSAT less than 20%. All the patients were assessed for their clinical status, medical history and comorbidities before the beginning of the therapy. Results: A collaboration between the two departments (Department of Transfusion Medicine and Department of Reconstructive Surgery) resulted in the application of a therapeutic protocol with erythropoietic stimulating agents (ESAs) (Binocrit 6000 UI/week) and intravenous iron every other day, starting the second day after surgery. Thirteen patients received ESAs and FCM (ferric carboxymaltose, 500-1000 mg per session), three patients received ESAs and iron gluconate (one vial every other day). No patients received blood transfusions. No side effects were observed, and most importantly, no limb or flap rejection occurred. Conclusions: Preliminary data from our protocol show an optimal therapeutic response, notwithstanding the very limited scientific literature and data available in this specific surgical field. The enrollment of further patients will allow us to validate this therapeutic protocol with statistically sound data.

Understanding Intraoperative Transfusion Decision-Making Variability: A Qualitative Study

There is evidence of significant intraoperative red blood cell (RBC) transfusion variability that cannot be explained by case-mix, and may reflect unwarranted transfusions. The objective was to explore the source of intraoperative RBC transfusion variability by eliciting the beliefs of anesthesiologists and surgeons that underlie transfusion decisions. Interviews based on the Theoretical Domains Framework were conducted to identify beliefs about intraoperative transfusion. Content analysis was performed to group statements into domains. Relevant domains were selected based on frequency of beliefs, perceived influence on transfusion, and the presence of conflicting beliefs within domains. Of the 28 transfusion experts recruited internationally (16 anesthesiologists, 12 surgeons), 24 (86%) were Canadian or American and 11 (39%) identified as female. Eight relevant domains were identified: (1) Knowledge (insufficient evidence to guide intraoperative transfusion), (2) Social/professional role and identity (surgeons/anesthesiologists share responsibility for transfusions), (3) Beliefs about consequences (concerns about morbidity of transfusion/anemia), (4) Environmental context/resources (transfusions influenced by type of surgery, local blood supply, cost of transfusion), (5) Social influences (institutional culture, judgment by peers, surgeon-anesthesiologist relationship, patient preference influencing transfusion decisions), (6) Behavioral regulation (need for intraoperative transfusion guidelines, usefulness of audits and educational sessions to guide transfusion), (7) Nature of the behaviors (overtransfusion remains commonplace, transfusion practice becoming more restrictive over time), and (8) Memory, attention, and decision processes (various patient and operative characteristics are incorporated into transfusion decisions). This study identified a range of factors underlying intraoperative transfusion decision-making and partly explain the variability in transfusion behavior. Targeted theory-informed behavior-change interventions derived from this work could help reduce intraoperative transfusion variability.

Association of Preoperative Blood Transfusion on Postoperative Outcomes in Emergency General Surgery

INTRODUCTION

Emergency general surgery (EGS) patients often present with anemia, in which preoperative transfusions are performed to mitigate anemia-associated risks. However, transfusions have also been noted to cause worse postoperative outcomes. This study examined how transfusion-associated outcomes vary at different levels of anemia.

MATERIALS AND METHODS

The American College of Surgeons National Surgical Quality Improvement Program database from 2005 to 2019 was used to identify patients who had undergone any of 12 major EGS procedures using Current Procedural Terminology codes. Patients were divided into two cohorts based on receipt of preoperative transfusion. Cohorts were subdivided into anemia severity levels and propensity score-matched within each using patient demographic and comorbidity variables. We analyzed 30-day postoperative outcomes, including morbidity, mortality, and return to odds ratio (OR), using univariate Chi-squared tests, Wilcoxon signed-rank tests, and multivariate logistic regression analyses.

RESULTS

595,407 EGS cases were identified. Receiving preoperative transfusion were 44.45% (n = 3058) of severely anemic, 10.94% (n = 9076) of moderately anemic, 1.34% (n = 1370) of mildly anemic, and 0.174% (n = 704) of no anemia patients. Transfusion resulted in an increased overall morbidity in the severe (OR 1.54), moderate (OR 1.50), mild (OR 1.71), and no anemia (OR 1.85) groups. Mortality increased in the moderate (OR 1.27), mild (OR 1.61), and no anemia (OR 1.76) subgroups. In severe anemia, transfusion status and mortality were not significantly associated.

CONCLUSIONS

Transfusion is associated with higher morbidity and mortality rates in those with higher hematocrit levels, even after controlling for pre-existing comorbidities. A restrictive transfusion strategy should be considered to avoid risks for those with a hematocrit level more than 24%.

A Retrospective Cohort Study of Red Cell Alloimmunisation in Rural, Remote, and Aboriginal and Torres Strait Islander Peoples Admitted to Intensive Care in the Northern Territory, Australia

Red cell (RC) alloantibodies occur on exposure to non-self RC antigens in transfusion and pregnancy (typically IgG and clinically significant) or in association with non-RC immune environmental factors (typically IgM and not clinically significant). In Australia, the risk of RC alloimmunisation in First Nations peoples is unknown. We assessed the epidemiology, specificity, and antecedents of RC alloimmunisation via a data linkage retrospective cohort study of Northern Territory (NT) intensive care unit (ICU) patients (2015-2019). Of 4183 total patients, 50.9% were First Nations. In First Nations versus non-First Nations patients, the period prevalence of alloimmunisation was 10.9% versus 2.3%, with 390 versus 72 prevalent alloantibodies detected in 232 versus 48 alloimmunised patients, of which 135 (34.6%) versus 52 (72.2%) were clinically significant specificities. Baseline and follow-up alloantibody testing were available for 1367 patients, in whom new incident clinically significant alloantibodies developed in 4.5% First Nations versus 1.1% non-First Nations patients. On Cox proportional hazards modelling, adjusted hazard ratios (HR) showed First Nations status (HR 2.67 (95% CI 1.05-6.80), p = 0.04) and cumulative RC unit transfusion exposure (HR 1.03 (95% CI 1.01-1.05), p = 0.01) were independent predictors of clinically significant alloimmunisation. First Nations Australian patients are at increased risk of alloimmunisation due to RC transfusion, underscoring the importance of very judicious use of RC transfusions and shared decision-making with patients. Further studies are recommended to explore the role of other (non-RC) immune host factors, given the relative high prevalence of non-clinically significant IgM alloantibodies within alloimmunised First Nations patients.

Lasso-Based Machine Learning Algorithm for Predicting Postoperative Lung Complications in Elderly: A Single-Center Retrospective Study from China

Background

The predictive effect of systemic inflammatory factors on postoperative pulmonary complications in elderly patients remains unclear. In addition, machine learning models are rarely used in prediction models for elderly patients.

Patients and Methods

We retrospectively evaluated elderly patients who underwent general anesthesia during a 6-year period. Eligible patients were randomly assigned in a 7:3 ratio to the development group and validation group. The Least logistic absolute shrinkage and selection operator (LASSO) regression model and multiple logistic regression analysis were used to select the optimal feature. The discrimination, calibration and net reclassification improvement (NRI) of the final model were compared with "the Assess Respiratory Risk in Surgical Patients in Catalonia" (ARISCAT) model.

Results

Of the 9775 patients analyzed, 8.31% developed PPCs. The final model included age, preoperative SpO2, ANS (the Albumin/NLR Score), operation time, and red blood cells (RBC) transfusion. The concordance index (C-index) values of the model for the development cohort and the validation cohort were 0.740 and 0.748, respectively. The P values of the Hosmer-Lemeshow test in two cohorts were insignificant. Our model outperformed ARISCAT model, with C-index (0.740 VS 0.717, P = 0.003) and NRI (0.117, P < 0.001).

Conclusion

Based on LASSO machine learning algorithm, we constructed a prediction model superior to ARISCAT model in predicting the risk of PPCs. Clinicians could utilize these predictors to optimize prospective and preventive interventions in this patient population.

CFNAs of RBCs affect the release of inflammatory factors through the expression of CaMKIV in macrophages

BACKGROUND

Blood transfusions reportedly modulate the recipient's immune system. Transfusion-related immunomodulation has been suggested as a mechanism of some adverse clinical outcomes. Extracellular nucleic acids circulate in plasma and activate relevant immune responses, but little is known about their mechanism of action in transfusion-related immunomodulation (TRIM). The aim of this study was to investigate the effects of cell-free nucleic acids (CFNAs) produced by red blood cells (RBCs) on innate immunity, especially peripheral blood mononuclear cells (PBMCs) and macrophages, and to investigate the mechanism of action.

METHODS

Differentially expressed genes (DEGs) between PBMCs exposed to RBC-produced CFNA and normal PBMCs were analyzed by gene expression data combined with bioinformatics. KEGG and GO enrichment analyses were performed for the DEGs, and in vitro experiments were performed for the effects of key genes on the release of inflammatory factors from macrophages.

RESULTS

Analysis of microarray data showed that exposure of monocytes to RBC-produced CFNAs increased the expression of genes involved in the innate immune response, including chemokines, chemokine receptors, and innate response receptors, and that calcium channel activity was highly regulated, with a key gene being CaMKIV. CaMKIV played a critical role in LPS-induced inflammatory factor release from macrophages, which was exacerbated by overexpression of the CaMKIV gene.

CONCLUSION

RBCs regulate the release of inflammatory factors during blood transfusion by releasing CFNAs and affecting expression of the CaMKIV gene in PBMCs or macrophages, which is a potential regulatory mechanism of blood transfusion-related immune regulation and related adverse reactions.

Cell Salvage in Oncological Surgery, Peripartum Haemorrhage and Trauma

Oncological surgery, obstetric haemorrhage and severe trauma are the most challenging conditions for establishing clinical recommendations for the use of cell salvage. When the likelihood of allogeneic transfusion is high, the intraoperative use of this blood-saving technique would be justified, but specific patient selection criteria are needed. The main concerns in the case of oncological surgery are the reinfusion of tumour cells, thereby increasing the risk of metastasis. This threat could be minimized, which may help to rationalize its indication. In severe peripartum haemorrhage, cell salvage has not proven cost-effective, damage control techniques have been developed, and, given the risk of fetomaternal alloimmunization and amniotic fluid embolism, it is increasingly out of use. In trauma, bleeding may originate from multiple sites, coagulopathy may develop, and it should be evaluated whether re-transfusion of autologous blood collected from uncontaminated organ cavities would be feasible. General safety measures include washing recovered blood and its passage through leukocyte depletion filters. To date, no well-defined indications for cell salvage have been established for these pathologies, but with accurate case selection and selective implementation, it could become safe and effective. Randomized clinical trials are urgently needed.

Intraoperative Red Blood Cell Transfusion Decision-making: A Systematic Review of Guidelines

OBJECTIVES

The objective of this work was to carry out a systematic review of clinical practice guidelines (CPGs) pertaining to intraoperative red blood cell (RBC) transfusions, in terms of indications, decision-making, and supporting evidence base.

SUMMARY OF BACKGROUND DATA

RBC transfusions are common during surgery and there is evidence of wide variability in practice.

METHODS

Major electronic databases (MEDLINE, EMBASE, and CINAHL), guideline clearinghouses and Google Scholar were systematically searched from inception to January 2019 for CPGs pertaining to indications for intraoperative RBC transfusion. Eligible guidelines were retrieved and their quality assessed using AGREE II. Relevant recommendations were abstracted and synthesized to allow for a comparison between guidelines.

RESULTS

Ten guidelines published between 1992 and 2018 provided indications for intraoperative transfusions. No guideline addressed intraoperative transfusion decision-making as its primary focus. Six guidelines provided criteria for transfusion based on hemoglobin (range 6.0-10.0 g/dL) or hematocrit (<30%) triggers. In the absence of objective transfusion rules, CPGs recommended considering other parameters such as blood loss (n = 7), signs of end organ ischemia (n = 5), and hemodynamics (n = 4). Evidence supporting intraoperative recommendations was extrapolated primarily from the nonoperative setting. There was wide variability in the quality of included guidelines based on AGREE II scores.

CONCLUSION

This review has identified several clinical practice guidelines providing recommendations for intraoperative transfusion. The existing guidelines were noted to be highly variable in their recommendations and to lack a sufficient evidence base from the intraoperative setting. This represents a major knowledge gap in the literature.

The Prevalence of unexpected antibodies in Saudi's plasma prior blood transfusion and their association with clinical conditions: A cross-sectional study

Unexpected antibodies, also called irregular antibodies, are not known to exist in a person's serum before testing. This research aims to assess the prevalence of unexpected antibodies and their correlation with several clinical conditions. This cross-sectional prospective study, undertaken from June 2019 to June 2020, included ABO, Rh grouping, cross-matching, and antibody screening. Antibody identification was performed only on patients who tested positive in the screening test. From a total of 9764 participants who were screened for unexpected antibodies, 107 (1.1%) tested positive. The Rh blood group system antibodies were the most frequent, particularly anti-D. There was also a significant correlation between the unexpected antibodies and history of transfusion, pregnancy, and autoimmune diseases as P ≤ 0.05. The most prominent unexpected antibodies in the study belong to the Rh system (Anti-D). Moreover, as a result of the strong correlation between the unexpected antibodies as well as the history of transfusion, pregnancy, and autoimmune diseases, the highest safety criteria must be followed during the transfusion of blood to patients with these clinical conditions.

Anemia as a Risk Factor for Organ Dysfunctions in Patients Operated on Heart Valves

Aim      To study the effects of pre- and postoperative anemia on the risk and the structure of internal organ dysfunction in patients undergoing surgery for acquired heart diseases (AHD).Material and methods  This was a retrospective cohort study including 610 primarily operated patients with AHD. A comparative analysis of the incidence and the structure of internal organ dysfunction was performed, and the likelihood of intraoperative hemotransfusion was determined for patients with preoperative anemia (Hb &lt;130 g/l) and without it. The incidence and the nature of internal organ damage were compared in patients with postoperative Hb &lt; 90 g/l and 90-130 g/l.Results The presence of postoperative anemia detected in 45 % of patients at two days after the surgery 6-fold increased the risk of acute heart failure (odds ratio [OR], 5.75; 95 % confidence interval [CI], 1.23-26.84; р=0.016), 4-fold increased the risk of multiorgan failure (MOF) (OR, 4.2; 95 % CI, 1.16-15.64; р=0.03), and 5-fold increased the likelihood of hemotransfusion (OR, 4.74; 95 % CI, 3.12-7.19; р&lt;0.0001). Severe and moderate anemia (Hb &lt;90 g/l) was observed in 11.2 % of patients, which presence 6-fold increased the risk of brain dysfunction (OR, 5.72; 95 % CI, 2.17-15.06; р=0.001) and MOF (OR, 5.97; 95 % CI, 1.94-18.35; р=0.004) compared to patients with Hb 90-130 g/l.Conclusion      In patients with AHD, postoperative anemia increases the risk of circulatory decompensation at two days after the surgery and of MOF and also increases the likelihood of intraoperative hemotransfusion; postoperative anemia with Hb &lt;90 g/l increases the risk of brain damage and MOF.

Effect of intraoperative blood transfusion on Treg and FOXP3 in patients with digestive tract malignancies and different ABO blood types

Background

Blood transfusion can cause immunosuppression and lead to worse outcomes in patients with digestive tract malignancies; however, the specific mechanism behind this is not completely understood. One theory is that increased numbers of regulatory CD3⁺CD4⁺CD25⁺FOXP3⁺ T cells (Tregs) and forkhead box protein-3 mRNA (FOXP3) expression in the blood after transfusion contribute to these outcomes. The effect of blood transfusion on immune function in patients with different ABO blood types is variable. This study investigates the effect of intraoperative blood transfusion on the number of Tregs and the expression of FOXP3 in the blood of patients with different ABO blood types and digestive tract malignancies.

Methods

Patients with digestive tract malignancies who underwent radical resection and received intraoperative blood transfusion were divided into four groups according to their blood types:blood group A, blood group B, blood group O and blood group AB (n = 20 for each group). Blood was collected from all patients before surgery, immediately after transfusion, 1 day after transfusion, and 5 days after transfusion. The number of Tregs was measured by flow cytometry. The expression of FOXP3 was detected by real time reverse transcription polymerase chain reaction (RT-PCR).

Results

There was no significant difference in the number of Tregs or expression of FOXP3 mRNA among patients with different blood types before surgery. However, the number of Tregs and the expression of FOXP3 increased after blood transfusion in all blood type groups. This increase was especially evident and statistically significant on the first day after blood transfusion when compared with measures obtained before the surgery. Measures returned to the preoperative level five days after surgery. There were significant differences in the increase of Tregs and expression of FOXP3 among patients with different blood types. The greatest increase was seen in patients with blood group B and the least in blood group A.

Conclusions

Intraoperative blood transfusion can lead to an increase in blood Tregs and FOXP3 expression in patients with digestive tract malignancies. Increases were greatest on the first day after surgery and differed among patients with different blood types. Increases were greatest in blood type B and least in blood type A.

There is no dose-response relationship between allogeneic blood transfusion and healthcare-associated infection: a retrospective cohort study

Background

The association between allogeneic blood transfusion and healthcare-associated infection (HAI) is considered dose-dependent. However, this association may be confounded by transfusion duration, as prolonged hospitalization stay increases the risk of HAI. Also, it is not clear whether specific blood products have different dose–response risks.

Methods

In this retrospective cohort study, a logistic regression was used to identify confounding factors, and the association between specific blood products and HAI were analyzed. Then Cox regression and restricted cubic spline regression was used to visualize the hazard of HAI per transfusion product.

Results

Of 215,338 inpatients observed, 4.16% were transfused with a single component blood product. With regard to these transfused patients, 480 patients (5.36%) developed a HAI during their hospitalization stay. Logistic regression showed that red blood cells (RBCs) transfusion, platelets transfusion and fresh-frozen plasmas (FFPs) transfusion were risk factors for HAI [odds ratio (OR) 1.893, 95% confidence interval (CI) 1.656–2.163; OR 8.903, 95% CI 6.646–11.926 and OR 1.494, 95% CI 1.146–1.949, respectively]. However, restricted cubic spline regression analysis showed that there was no statistically dose–response relationship between different transfusion products and the onset of HAI.

Conclusions

RBCs transfusion, platelets transfusion and FFPs transfusion were associated with HAI, but there was no dose–response relationship between them.

The Trajectory of Alterations in Immune-Cell Counts in Severe-Trauma Patients Is Related to the Later Occurrence of Sepsis and Mortality: Retrospective Study of 917 Cases

Background

Severe trauma is believed to disrupt the homeostasis of the immune system, and lead to dramatic changes in the circulating immune-cell count (ICC). The latter fluctuates widely over time. Knowledge about the relationship between these dramatic changes and dynamic fluctuations and the late prognosis of trauma patients is sparse. We investigated the relationship between the trajectory of alterations in the circulating ICC within 7 days in severe-trauma patients and subsequent sepsis and mortality.

Methods

A retrospective analysis of 917 patients with an Injury Severity Score ≥16 was undertaken. The absolute neutrophil, lymphocyte, and monocyte counts (ANC, ALC, and AMC, respectively) on days 1, 3, and 7 (D1, D3, and D7, respectively) after trauma, and whether sepsis or death occurred within 60 days, were recorded. As the disordered circulating ICCs fluctuated widely, their time-varying slopes (D3/D1 and D7/D3) were calculated. Patients were divided into “sepsis” and “non-sepsis” groups, as well as “alive” and “death” groups. Comparative studies were conducted between every two groups. Univariate and multivariate logistic regression analyses were used to identify variables related to the risk of sepsis and mortality. Receiver operating characteristic curves were plotted to assess the predictive value of various risk factors.

Results

More severe trauma caused more pronounced increases in the ANC and slower recovery of the ALC within 7 days. The ALC (D3), ANC (D7), ALC (D3/D1), and ANC (D7/D3) were independent risk factors for sepsis. The ALC (D3), ALC (D7), AMC (D7), and ALC (D3/D1) were independent risk factors for mortality. A combination of the ALC (D3) and ALC (D3/D1) exerted a good predictive value for sepsis and death.

Conclusions

The trajectory of alterations in the circulating ICC in the early stage after trauma is related to subsequent sepsis and mortality.

The Effect of Preoperative Anemia and Perioperative Transfusion on Surgical Outcomes After Gastrectomy for Gastric Cancer

BACKGROUND

The aim of this study is to examine the interaction between preoperative anemia and perioperative transfusions with postoperative morbidity and mortality among patients undergoing gastrectomy for cancer.

MATERIALS AND METHODS

The American College of Surgeons National Surgical Quality Improvement Program database was queried from 2005 to 2016. Restricted cubic splines modeled the nonlinear relationship between preoperative hematocrit (Hct) and 30-day overall morbidity, sepsis, and mortality. Preoperative Hct was categorized based on cut points for the three models. Multiple regression modeling examined the interactive effect of preoperative anemia and postoperative transfusion on surgical outcomes.

RESULTS

Among 9936 included patients, complication incidence was 38.9% (sepsis 12.7%; mortality 6.0%). Preoperative Hct cut points were identified at 29 and 42. Hct <29 was associated with higher risk of morbidity (OR 2.47, 95%CI 2.10-2.93). Postoperative transfusion was associated with lower risk of morbidity for Hct <29 (OR 0.56, 95%CI 0.43-0.73) but increased risk between 29 and 42 (OR 1.59, 95%CI 1.21-2.08). Similar relationships were found for sepsis and mortality.

CONCLUSIONS

Preoperative Hct <29 is associated with an increased risk of surgical complications after gastrectomy for cancer and perioperative transfusions appear to be beneficial for Hct <29 only. There may be a role for better optimization of red cell mass among high-risk patients before gastrectomy for cancer.

Blood transfusion and lung surgeries in pediatric age group: A single center retrospective study

Background:

Blood transfusion is not without harm, and recent studies suggest association between transfusion and poor outcome in critically ill patients. Although it is prescribed for many reasons based on the firm belief that blood transfusion improves oxygen carrying capacity, it carries notable adverse hazards. Importantly, lung surgeries are counted as moderate to high-risk operations and take a significant risk of blood loss.

Aim:

This study aims to reveal the association between blood transfusion and poor clinical outcomes and characterize the epidemiology of blood transfusion after pediatric chest surgery.

Settings and Design:

Retrospective cohort study, done throughout 3 years.

Materials and Methods:

A total of 248 patients who underwent open thoracotomy and lung surgery and aged ≤18 years were classified according to the need of intraoperative or postoperative blood transfusion into two groups: Group I (non-transfused = 130) and Group II (transfused = 118).

Statistical Analysis:

SPSS v25 was used for analysis.

Results:

Transfusion probability ranged between 42.8% and 50% according to type of surgery. As regard to postoperative variables, there was no significant difference between both groups regarding the duration of analgesia, allergic reactions, need of re-operation and in-hospital mortality. However, transfused group showed significant increase in duration of antibiotic, persistent postoperative fever, time to remove chest drains, ICU stays, hospital stay and pneumonia. Incidence of pneumonia had a relative risk 1.82 with transfused compared to non-transfused group.

Conclusion:

Transfusion group in pediatrics undergoing lung surgeries in our study was more prone to adverse outcomes such as pneumonia, delayed time to remove chest drains, prolonged ICU stay, and hospital stay.

Use of preoperative erythropoietin therapy to facilitate autologous blood donation in orthopedic surgery: A meta-analysis

BACKGROUND

Autologous blood transfusion helps to avoid or reduce the need for allogenic blood transfusion in patients undergoing major surgery. We examined the value of erythropoietin therapy to support preoperative autologous blood donation (PABD) in patients undergoing orthopedic surgery.

METHODS

For this systematic review and meta-analysis, Medline, Cochrane, EMBASE, and Google Scholar databases were searched from October 26th, 1989 until September 30th, 2017. Primary outcomes were percentages of patients able to donate ≥4 units of blood for autologous transfusion, amount of allogeneic blood transfused, changes in hematocrit and hemoglobin levels from before PABD to immediately before surgery, and adverse events.

RESULTS

Of 256 studies identified, 18 studies met the inclusion criteria with a total of 1914 patients (mean age 51-69 years), of whom 1153 were treated with erythropoietin. Erythropoietin was associated with a greater percentage of patients able to donate ≥4 units of blood for autologous use compared to controls (OR = 6.00, 95% CI = 3.97 to 9.09, P < .001). Patients receiving preoperative erythropoietin had significantly less of a reduction in hematocrit and hemoglobin levels from before PABD to immediately before surgery compared with controls (hematocrit: mean differences = -1.438, 95% CI = -2.14 to -0.73, P < .001; hemoglobin: mean differences = -1.426, 95% CI = -1.78 to -1.07, P < .001). No significant differences were observed in the amount of allogenic blood transfused between patients receiving erythropoietin and controls (difference in means = -0.220, 95% CI = -0.536 to 0.097, P = .174). Patients who received erythropoietin were less likely to experience dizziness than controls, but the incidence of nausea or fatigue were similar between groups.

CONCLUSION

Erythropoietin therapy during the PABD period results in less of a reduction in hematocrit and hemoglobin levels and an increase in the percentage of patients able to donate blood preoperatively.

Impact of perioperative red blood cell transfusion on postoperative recovery and long-term outcome in patients undergoing surgery for ovarian cancer: A propensity score-matched analysis

BACKGROUND

The impact of perioperative red blood cell transfusion (PRBCT) on cancer survival has remained controversial.

METHODS

We conducted a retrospective study in patients undergoing primary debulking surgery (PDS) for ovarian cancer between January 2013 and December 2017. The patients were divided into two groups based on whether they received PRBCT. Clinical characteristics were compared between groups. After propensity score matching, perioperative systemic inflammation-based scores, quality of recovery, postoperative outcomes, disease-free survival (DFS), and overall survival (OS) were compared between groups. Univariate and multivariable Cox proportional hazard models were used to evaluate the association between covariates and survival outcomes.

RESULTS

A total of 1037 patients were enrolled in this study, and 31.7% of patients received PRBCT. After propensity matching, there was no significant difference in the clinical characteristics between groups. Patients receiving PRBCT had more postoperative fluctuations in systemic inflammatory response-related indicators (P < 0.001), a higher incidence of postoperative grade II complications (28.4% vs. 14.8%), a longer length of stay (10.6 d vs. 6.2 d) and higher 30-day and total readmission rates (7.1% vs. 4.4% and 11.2% vs. 8.1%, P < 0.001, respectively) than patients who did not receive PRBCT. The OS and DFS rates 3 years after surgery were significantly lower in the patients receiving PRBCT than in patients not receiving PRBCT (58.9% vs. 74.5%, 39.6% vs. 52.3%).

CONCLUSIONS

PRBCT was significantly associated with more fluctuations in systemic inflammatory indicators, a prolonged length of stay, higher postoperative complication rates and increased cancer recurrence and overall mortality in ovarian cancer patients undergoing PDS.

Comparison of the blood parameters and histopathology between grass carp infected with a virulent and avirulent isolates of genotype II grass carp reovirus

Grass carp hemorrhagic disease caused by grass carp reovirus (GCRV) is the most important disease for grass carp aquaculture. Its typical clinical symptom is haemorrhaging, although the mechanism was remained unclear. In this study, we investigated the differences in blood parameters and histopathological features between grass carp infected with a virulent and avirulent isolates of genotype II GCRV. Infection with the virulent isolate resulted in increases in 8 routine blood and 2 serum biochemical parameters (P < 0.05); while 9 routine blood and 5 biochemical parameters were significantly decreased (P < 0.05) compared with fish infected with the avirulent isolate. The majority of these alterations were related to hemorrhage, inflammatory reactions and organic damage. The histopathologic changes were primarily vasodilation and hyperaemia in multiple organs, lymphocyte and macrophage infiltration as well as severe vacuolar degeneration in spleen, kidney and liver. The histopathology changes in fish infected with the avirulent isolate were minimal. These results indicated that the pathogenicity of GCRV was primarily reflected in destruction of the blood circulatory system and parenchymatous organs. This study lays the foundation for further research on the pathogenesis of bleeding caused by GCRV infection and the use of blood parameters and histopathology as tools for disease diagnosis.

Perioperative Outcomes Following Pediatric Cranial Vault Remodeling: Are Improvements Possible?

PURPOSE

The Pediatric Craniofacial Collaborative Group recently reported pooled perioperative data from 31 North American centers performing open cranial vault remodeling procedures. The authors sought to determine if outcomes were different at a single higher-volume center and if identified, ascertain reasons for any differences and propose strategies for improvement.

METHODS

A retrospective review was performed of all open pediatric cranial vault procedures performed at our center during the identical 3.25-year period reported by the Collaborative group, including demographic, perioperative management and outcome data, to permit multiple comparative analyses.

RESULTS

The 310 procedures were performed by our center during this time period, compared to 1223 by the combined 31 institutions (median: 29.5 cases/center; interquartile range: 12-54.5). Multiple outcome differences were found: our higher-volume center had a significantly lower overall red blood cell transfusion rate (≤2 years: 7.5 percent vs 91 percent, P <0.001), those requiring transfusions were transfused considerably smaller volumes (≤2 years: 3.8mL/kg vs 45.3 mL/kg, P <0.001), and exposure to ≥3 blood donors was significantly less (none vs 20 percent, P <0.001). There were no mortalities in either group, but almost all matched adverse events were less common at our center. Both the intensive care unit and hospital lengths of stay were significantly shorter at our center (1 vs 2 days, 2 vs 4 days, both P <0.001).

CONCLUSIONS

Perioperative outcomes following pediatric craniosynostosis corrections performed at a single higher-volume center compare favorably to median national data. Multiple potential strategies to reduce blood utilization, minimize perioperative complications, and shorten hospitalizations are proposed.

MicroRNA Profiling of Exosomes Derived from Red Blood Cell Units: Implications in Transfusion-Related Immunomodulation

Purpose

To elucidate the microRNAs existent in exosomes derived from stored red blood cell (RBC) unit and their potential function.

Materials and Methods

Exosomes were isolated from the supernatant derived from stored RBC units by sequential centrifugation. Isolated exosomes were characterized by TEM (transmission electron microscopy), western blotting, and DLS (dynamic light scattering). MicroRNA (miRNA) microarray was performed to detect the expression of miRNAs in 3 exosome samples. Results revealed miRNAs that were simultaneously expressed in the 3 exosome samples and were previously reported to exist in mature RBCs. Functions and potential pathways of some detected miRNAs were illustrated by bioinformatic analysis. Validation of the top 3 abundant miRNAs was carried out by qRT-PCR (quantitative reverse transcription‐polymerase chain reaction).

Results

TEM and DLS revealed the mean size of the exosomes (RBC-derived) as 64.08 nm. These exosomes exhibited higher abundance of short RNA than the long RNA. 78 miRNAs were simultaneously detected in 3 exosome samples and mature RBCs. Several biological processes might be impacted by these miRNAs, through their target gene(s) enriched in a particular signalling pathway. The top 3 (abundant) miRNAs detected were as follows: miR-125b-5p, miR-4454, and miR-451a. qRT-PCR revealed higher abundance of miR-451a than others. Only miR-4454 and miR-451a abundance tended to increase with increasing storage time.

Conclusion

Exosomes derived from stored RBC units possessed multiple miRNAs and, hence, could serve various functions. The function of exosomes (RBC-derived) might be implemented partly by the predominantly enriched miR-451a.

Epidemiology of chronic red-cell transfusion recipients in Sweden and Denmark-a 10 year follow-up study

BACKGROUND AND OBJECTIVES

Chronic red-cell transfusions may be an indispensable part of patient treatment and may require early intervention to avoid adverse transfusion effects. The population of chronic transfusion recipients including common diagnoses and survival remains poorly characterised. Thus, the objective was to examine the complete range of chronic transfusion recipients, including demographic and patient characteristics and survival.

MATERIALS AND METHODS

All patients who received their first transfusion in Sweden or Denmark from January 1, 2002 to December 31, 2010 were followed up for subsequent transfusion episodes until December 31, 2012. Data on patient characteristics at time of the first and subsequent transfusions were retrieved from the national registers. We estimated the proportion of transfused patients who experienced 20 or more red-cell transfusion episodes (with an episode defined as all transfusions received 4 days or less apart) and characterised this patient population with respect to diagnoses, demographics and survival.

RESULTS

Among 893 117 first time red-cell transfusion recipients, 6157 (0·7%) experienced 20 or more episodes in total. The most common diagnoses among these patients were haematologic malignancies followed by non-haematologic malignancies and non-malignant blood and immune system related diseases. On average, chronically transfused patients had a median survival of less than 1 year following their 20th transfusion episode.

CONCLUSION

This study provides an overview of patient characteristics related to repeat red-cell transfusions and of the amount of red-cell transfusion episodes administered during a 10-year period in two countries. Patients who become chronically transfused suffer from diseases with poor prognosis.

A Hepatocyte-Mimicking Antidote for Alcohol Intoxication

Alcohol intoxication causes serious diseases, whereas current treatments are mostly supportive and unable to remove alcohol efficiently. Upon alcohol consumption, alcohol is sequentially oxidized to acetaldehyde and acetate by the endogenous alcohol dehydrogenase and aldehyde dehydrogenase, respectively. Inspired by the metabolism of alcohol, a hepatocyte-mimicking antidote for alcohol intoxication through the codelivery of the nanocapsules of alcohol oxidase (AOx), catalase (CAT), and aldehyde dehydrogenase (ALDH) to the liver, where AOx and CAT catalyze the oxidation of alcohol to acetaldehyde, while ALDH catalyzes the oxidation of acetaldehyde to acetate. Administered to alcohol-intoxicated mice, the antidote rapidly accumulates in the liver and enables a significant reduction of the blood alcohol concentration. Moreover, blood acetaldehyde concentration is maintained at an extremely low level, significantly contributing to liver protection. Such an antidote, which can eliminate alcohol and acetaldehyde simultaneously, holds great promise for the treatment of alcohol intoxication and poisoning and can provide therapeutic benefits.

Assessment of the prescription of red blood cell concentrates in the pediatric age group

OBJECTIVE

To verify the adequacy of red blood cell (RBC) prescription to pediatric patients in different sectors of a pediatric hospital.

METHOD

A retrospective study was conducted including 837/990 RBC transfusion requisition forms for children and adolescents (0 to 13 years old) filed in between January 2007 and April 2015 by the pediatricians of the emergency room (ER), infirmary ward and intensive care unit (pICU). Transfusion requisition forms belonging to patients with chronic anemia or acute hemorrhage, as well as incompletes requisition forms, were excluded.

RESULTS

Trigger, prescribed volume and subtype of RBC concentrates were adequate in 532 (65.3%), 460 (58.8%) and 805 (96.2%) of the transfusions, respectively. When the clinical picture was considered, prescription adequacy was higher compared to the use of the hemoglobin level alone (70.9% vs. 41%). The pICU had the highest correct trigger percentage (343 [71.6%]; p<0.001) while the ER showed more often adequate prescribed volumes (119 [66.1%]; p=0.020). The most common inadequacy regarding volume was that of prescriptions above the recommendation > 15 mL/kg found in 309 cases (36.9%). Thirty-two (32) RBC subtypes were requested and none were consistent with current recommendations.

CONCLUSION

The results obtained in our study showed that RBC transfusion occurred more appropriately when the clinical picture was taken into account at request. There was a tendency to prescribe higher volumes and RBC subtypes without the justification of current protocols. Hemotherapic teachings at undergraduate level and medical residency must be improved.

Early local delivery of vancomycin suppresses ectopic bone formation in a rat model of trauma-induced heterotopic ossification

Heterotopic ossification (HO) is a debilitating sequela of high-energy injuries. It frequently requires surgical excision once symptomatic and there is no practical prophylaxis for combat-injured patients. In this study, we examined the effect of local vancomycin powder on HO formation in a small animal model of blast-related, post-traumatic HO. Male Sprague-Dawley rats were subjected to a polytraumatic extremity injury and amputation with or without methicillin-resistant Staphylococcus aureus infection. Animals were randomized to receive a single local application of vancomycin (20 mg/kg) at the time of injury (POD-0, n = 34) or on postoperative day-3 (POD-3, n = 11). Quantitative volumetric measurement of ectopic bone was calculated at 12-weeks post-injury by micro-CT. Bone marrow and muscle tissues were also collected to determine the bacterial burden. Blood for serum cytokine analysis was collected at baseline and post-injury. Vancomycin treatment on POD-0 suppressed HO formation by 86% and prevented bone marrow and soft tissue infections. We concurrently observed a marked reduction histologically in nonviable tissue, chronic inflammatory cell infiltrates, bone infection, fibrous tissue, and areas of bone necrosis within this same cohort. Delayed treatment was significantly less efficacious. Neither treatment had a marked effect on the production of pro-inflammatory cytokines. Our study demonstrates that local vancomycin treatment at the time of injury significantly reduces HO formation in both the presence and absence of infection, with decreased efficacy if not given early. These findings further support the concept that the therapeutic window for prophylaxis is narrow, highlighting the need to develop early treatment strategies for clinical management. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2397-2406, 2017.

Blood transfusion in the surgical treatment of adolescent idiopathic scoliosis-a single-center experience of patient blood management in 210 cases

BACKGROUND

The surgical treatment of adolescent idiopathic scoliosis can be associated with substantial blood loss, requiring allogeneic red blood cell (RBC) transfusion. This study describes the use of RBC and the effect of a standardized perioperative patient blood management program.

STUDY DESIGN AND METHODS

Patients treated with posterior instrumented fusion were consecutively enrolled over a 6-year period. Patient blood management strategies were implemented in 2011, including prophylactic tranexamic acid, intraoperative permissive hypotension, restrictive fluid therapy (including avoidance of synthetic colloids), restrictive RBC trigger according to institutional standardized protocol, the use of cell savage, and goal-directed therapy according to thrombelastography.

RESULTS

In total, 210 patients were included. 64 patients (31%) received RBC transfusions. A decline in the intraoperative rate of RBC transfusion was observed, from 77% in 2011 to 13% in 2016 (p < 0.001). Patients in the transfusion group had a significantly larger major curve, lower preoperative hemoglobin, higher estimated blood loss, and an increased use of crystalloid volume resuscitation. Multiple logistic regression showed that significant predictors for RBC transfusion were preoperative hemoglobin level (odds ratio [OR], 0.40; 95% confidence interval [CI], 0.27-0.57), estimated blood loss (OR, 1.26; 95% CI, 1.15-1.42), and year of surgery (indicating the effect of patient blood management) (OR per year, 0.76; 95% CI, 0.58-0.99).

CONCLUSION

A perioperative patient blood management program substantially reduced the need for RBC transfusion. A preoperative evaluation of anemia is essential to further minimize transfusion rates.

Preoperative blood transfusion is a predictor of worse short-term postoperative outcomes after colectomy

BACKGROUND

Both anemia and blood transfusion are associated with poor outcomes. The aim of this study was to evaluate the effect of preoperative blood transfusion on postoperative outcomes after colectomy, stratified by severity of anemia.

METHODS

Patients undergoing colectomy from 2012-2014 were selected from the National Surgical Quality Improvement Program targeted colectomy database. Patients were divided into 2 groups based on receipt of preoperative transfusion and then stratified by hematocrit. Univariate and multivariate analyses were used to compare 30-day outcomes between the 2 groups.

RESULTS

A total of 60,785 patients were included in the study, with an overall preoperative transfusion rate of 3.4% (n = 2,073). On univariate analysis, transfusion was associated with significantly greater rates of postoperative morbidity. The risk-adjusted, multivariate model confirmed increased risk of complications with preoperative transfusion (odds ratio 1.32, 95% confidence interval, 1.18-1.48). Furthermore, transfusion did not improve outcomes even in the setting of moderate anemia (odds ratio 1.35, 95% confidence interval, 1.14-1.60) or severe anemia (odds ratio 0.97, 95% confidence interval, 0.66-1.41).

CONCLUSIONS

Preoperative transfusion is an independent predictor of complications in patients with mild and moderate anemia. Furthermore, these retrospective data suggest that even severely anemic patients do not benefit from preoperative transfusion and empiric transfusion therefore should be avoided. Alternatives to preoperative optimization of this high-risk surgical population should be sought.

Transfusion in critical care - a UK regional audit of current practice

A consistent message within critical care publications has been that a restrictive transfusion strategy is non-inferior, and possibly superior, to a liberal strategy for stable, non-bleeding critically ill patients. Translation into clinical practice has, however, been slow. Here, we describe the degree of adherence to UK best practice guidelines in a regional network of nine intensive care units within Wessex. All transfusions given during a 2-month period were included (n = 444). Those given for active bleeding or within 24 h of major surgery, trauma or gastrointestinal bleeding were excluded (n = 148). The median (IQR [range]) haemoglobin concentration before transfusion was 73 (68-77 [53-106]) g.l^-1 , with only 34% of transfusion episodes using a transfusion threshold of < 70 g.l^-1 . In a subgroup analysis that did not study patients with a history of cardiac disease (n = 42), haemoglobin concentration before transfusion was 72 (68-77 [50-98]) g.l^-1 , with only 36% of transfusion episodes using a threshold of < 70 g.l^-1 (see Fig. 3). Most blood transfusions given to critically ill patients who were not bleeding in this audit used a haemoglobin threshold > 70 g.l^-1 . The reason why recommendations on transfusion triggers have not translated into clinical practice is unclear. With a clear national drive to decrease usage of blood products and clear evidence that a threshold of 70 g.l^-1 is non-inferior, it is surprising that a scarce and potentially dangerous resource is still being overused within critical care. Simple solutions such as electronic patient records that force pause for thought before blood transfusion, or prescriptions that only allow administration of a single unit in non-emergency circumstances may help to reduce the incidence of unnecessary blood transfusions.

A high-throughput microfluidic approach for 1000-fold leukocyte reduction of platelet-rich plasma

Leukocyte reduction of donated blood products substantially reduces the risk of a number of transfusion-related complications. Current 'leukoreduction' filters operate by trapping leukocytes within specialized filtration material, while allowing desired blood components to pass through. However, the continuous release of inflammatory cytokines from the retained leukocytes, as well as the potential for platelet activation and clogging, are significant drawbacks of conventional 'dead end' filtration. To address these limitations, here we demonstrate our newly-developed 'controlled incremental filtration' (CIF) approach to perform high-throughput microfluidic removal of leukocytes from platelet-rich plasma (PRP) in a continuous flow regime. Leukocytes are separated from platelets within the PRP by progressively syphoning clarified PRP away from the concentrated leukocyte flowstream. Filtrate PRP collected from an optimally-designed CIF device typically showed a ~1000-fold (i.e. 99.9%) reduction in leukocyte concentration, while recovering >80% of the original platelets, at volumetric throughputs of ~1 mL/min. These results suggest that the CIF approach will enable users in many fields to now apply the advantages of microfluidic devices to particle separation, even for applications requiring macroscale flowrates.

AAGBI guidelines: the use of blood components and their alternatives 2016

Blood transfusion can be life-saving. Anaesthetists regularly request and administer blood components to their patients. All anaesthetists must be familiar with indications and appropriate use of blood and blood components and their alternatives, but close liaison with haematology specialists and their local blood sciences laboratory is encouraged. Considerable changes in approaches to optimal use of blood components, together with the use of alternative products, have become apparent over the past decade, leading to a need to update previous guidelines and adapt them for the use of anaesthetists working throughout the hospital system.

Transfusion practices and infectious risks

Transfusion-transmitted infections remain among the most-feared complications of allogeneic blood transfusion. Thanks to several strategies including donor screening and deferral, blood testing and pathogen inactivation, their risks have reached all-time low levels, particularly in developed nations. Nonetheless, new and emerging infections remain a threat that is likely to exacerbate in the coming years with continued globalization and climate change. More effective strategies of pathogen inactivation and more vigilant horizon screening are hoped to abate the risk. Additionally, allogeneic transfusion has repeatedly been shown to be associated with worsening of outcomes in patients, including the documented increased risk of infections (often nosocomial) in recipients of transfusions. The underlying mechanism is likely to be related to immunosuppressive effects of allogeneic blood, iron content, and bacterial contamination. This issue is best addressed by more judicious and evidence-based use of allogeneic blood components to ensure the potential benefits outweigh the risks.

Nanostructural Changes in the Cell Membrane of Gamma-Irradiated Red Blood Cells

The effect of gamma radiation on the ultrastructure of the cell membranes of red blood cells has been probed using a powerful tool, namely, atomic force microscopy. We used mice erythrocytes as a model. Blood samples withdrawn from mice were gamma-irradiated using a ⁶⁰Co source unit with doses of 10,15,20,25 and 30 Gy. Structural changes appeared in the form of nanoscale potholes, depressions and alterations of the cell membrane roughness. The roughness of the cell membrane increased dramatically with increasing doses, although at 10 Gy , the cell membrane roughness was less than that of normal red blood cells (controls). Therefore, such modifications at the nano-scale level may affect the biophysical properties of membranes, resulting in impairment of their function.