Transfusion In Sickle Cell Disease Research Articles

Alloimmunization and hyperhemolysis in sickle cell disease.

Alloimmunization against red blood cell antigens and delayed hemolytic transfusion reaction (DHTR) are major barriers to transfusion in sickle cell disease (SCD). In SCD, DHTR is a potentially life-threatening. Blood group polymorphism in SCD patients, who are of African ancestry and frequently exposed to antigens they do not carry; an inflammatory clinical state; and occasional transfusion in acute situations are risk factors for alloimmunization and DHTR. In patients at risk, the transfusion indication must be balanced against the risk of developing DHTR. However, when transfusion is absolutely necessary, protocols combining the prevention of exposure to immunogenic antigens with immunosuppressive treatments must be implemented, and patients should be carefully monitored during posttransfusion follow-up. This close monitoring makes it possible to diagnose hyperhemolysis as soon as possible; to avoid retransfusion, which can exacerbate hemolysis; and to administer specific treatments, such as anticomplement therapy, in severe cases. Finally, in patients with severe disease, hematopoietic stem cell transplantation may be indicated. However, transfusion is also required in this context, and its management is complex because these risks must be taken into account.

Preoperative Exchange Transfusion for Patients with SCD Systematic Review

Introduction: Sickle cell disease (SCD) is the most common genetic disease world wide with the highest prevalence in Africa, Middle east, and east Asia. Surgeries in patients with SCD are associated with a higher rate of perioperative complications, however, there is no solid recommendations in the guidelines to advice perioperative transfusion strategies in patients with SCD. This review investigated the current available evidence in the literature to provide a clearer guidance. Methods: PubMed and Embase electronic search identified 655 articles related to randomized controlled trials and observational studies about the safety of perioperative transfusion in SCD. After removing duplicates and non-relevant articles 39 articles were evaluated in full text for eligibility, of which 24 studies were found eligible for inclusion in qualitative analysis and 16 studies with 3486 participants eligible for inclusion in the quantitative analysis. Assessment of quality and risk of Bias was done using the Cochrane tool for RCTs and ROBBINS-I tool for observational non randomized studies. The safety outcomes of perioperative transfusion, including acute chest syndrome (ACS), painful crisis, neurological complications, fever, minor or major bleeding, thrombosis, intensive care unit (ICU) admission, and all-cause mortality were assessed in comparison to SCD patients undergoing surgeries with conservative transfusion strategy. The risk ratio (RR) with 95% confidence intervals (CI) were calculated for the desired outcomes, the data was combined in forest plots and meta-analysis using the random-effects model. Results: Of the 24 studies included, 13 studies had the control arm as no transfusion in comparison to perioperative transfusion, while the remaining studies had conservative strategy guided by hemoglobin level as a control. Sixteen studies reported ACS among SCD patients who received perioperative transfusion (n=1890) versus conservative transfusion strategy (n=1596) (RR= 0.91, 95% CI 0.58-1.41, I2= 58%) (Figure 1-A). Fifteen studies reported painful crisis with perioperative transfusion (n=1856) versus conservative transfusion strategy (n=1532) (RR= 0.94, 95% CI 0.53-1.68, I2= 63%) (Figure 1-B). Neurological complications associated with the perioperative transfusion in SCD (n=1590) compared to conservative transfusion strategy (n=1250) were reported in nine studies (RR= 1.38, 95% CI 0.54-3.57, I2= 0%). Seven studies reported fever as a post-operative complication following perioperative transfusion in SCD (n= 1243) versus conservative transfusion (n= 922) (RR= 1.36, 95% CI 0.94-1.97, I2= 51%). Six studies reported bleeding following perioperative transfusion in SCD (n= 847) versus conservative strategy (n= 477) (RR= 4.32, 95% CI 1.75-10.68, P=0.002, I2= 0%) (Figure 1-C). Three studies reported thrombotic events following the perioperative transfusion in SCD (n= 885) versus conservative transfusion (n= 404) (RR= 0.59, 95% CI 0.06-5.68, I2= 0%). ICU admissions were reported in three studies with perioperative transfusion (n= 53) versus conservative transfusion (n= 147) (RR= 4.99, 95% CI 0.98-25.48, I2= 0%). Mortality was reported in six studies with perioperative transfusion (n= 1320) versus conservative transfusion (n= 977) (RR= 0.67, 95% CI 0.05-8.75, I2= 71%). Conclusion: According to this systematic review and meta-analysis Perioperative transfusion in SCD resulted in significantly higher rate of bleeding compare to conservative strategies while the rates of acute chest syndrome, painful crisis, fever, neurological complications, thrombosis, ICU admission, and mortality remained similar between the two strategies.

Red blood cell transfusion in sickle cell disease.

Red blood cell transfusion in sickle cell disease.

Palatability and Acceptability of Flaxseed-Supplemented Foods in Children with Sickle Cell Disease.

Omega-3 fatty acids (w3FAs) have demonstrated benefits in several inflammatory disease states; however, limited research has been conducted in sickle cell disease (SCD). While marine-based w3FAs are used, their strong odor and taste are a barrier to long-term use. Plant-based sources, especially those in whole foods, may circumvent this barrier. We tested whether flaxseed (rich source of w3FAs) was acceptable to children with SCD. A cross-sectional tasting trial of flaxseed added to baked products (cookies, pancakes, brownies) or to readily available foods (applesauce, pudding, yogurt) was conducted among 30 children (median age = 13 years) reporting to a clinic for routine follow-up, sick visits, or transfusion for SCD to determine acceptability. A food preference rank scale (1-7) was used to rank products based on taste, sight, smell, and texture. An average score for each product was computed. Children were also asked to rank their top three products. The top-ranked products were flaxseed baked in brownies and cookies and ground flaxseed added to yogurt. More than 80% of participants indicated willingness to be contacted for a follow-up study in which a flaxseed-supplemented diet would be evaluated for mitigation of SCD-associated pain. In conclusion, flaxseed-enriched products are palatable and acceptable in children with SCD.

Prevalence of Transfusion-Transmitted Infections in Multi-Transfused Thalassemia and Sickle Cell Disease Patients: A Single Center Experience from Southern Odisha, India

ABSTRACT Background: Repeated transfusion in sickle cell disease (SCD) and transfusion-dependent thalassemia (TDT) patients lead to transfusion-transmitted infections (TTIs). The prevalence, as well as various risk factors for TTIs in these patients, is found to be inconsistent. This study aimed to observe the prevalence, types of infections as well as risk factors for TTIs in a tertiary health care center. Materials and Methods: This observational study was undertaken on both SCD and TDT patients admitted to the hospital for a transfusion. In all patients, the enzyme-linked immunosorbent assay-based test kit was used for the diagnosis of hepatitis C virus (HCV), hepatitis B virus (HBV), and human immunodeficiency virus 1 and 2 (HIV 1 and 2). However, a rapid test kit was used for the diagnosis of malaria and syphilis. Detailed information on age of the patients, duration of transfusion, and number of transfusion as risk factors were recorded. The association of factors with various infections was analyzed statistically. Results: A total of 153 patients were recruited including 49 SCD and 104 TDT patients. Of 153 patients, 25 patients were found to have infections including HCV in 22 (14.38%) patients, HBV in 2 (1.31%) patients, and HIV in 2 patients (1 patient was positive for both HCV and HBV). Out of 25 TTIs patients, 7 patients had SCD and 18 patients had TDT. On the association, only an increased number of transfusion per year was found to be significantly associated with TTIs (P = 0.008) in SCD patients. However, all the risk factors were found to be associated with TTIs except gender in TDT patients. Conclusion: The occurrence of TTIs was found to be associated with older patients, increased number of transfusion per year, and large duration of transfusion. The increasing trend in the TTIs in these patients calls for a shift toward preventive and comprehensive care to reduce the health burden.

Dietary Iron Restriction Alters Microbiota-Host Crosstalk and Protects Against Vaso-Occlusion and Organ Damage in Sickle Cell Disease Mice

Introduction: Sickle cell disease (SCD) is the most commonly inherited monogenic hemoglobinopathy and results from a mutation in the β-globin gene (HbS), leading to red blood cell (RBC) sickling, vaso-occlusive episodes (VOE), and organ damage. Chronic hemolysis, inflammation, and repeated red blood cell transfusions in SCD can disrupt iron homeostasis. Patients who receive multiple blood transfusions develop iron-overload, and another subpopulation of SCD patients manifest iron deficiency. SCD mice exhibit increased iron absorption via upregulation of the intestinal transcription factor hypoxia inducible factor-2a(HIF-2a) leading to the development of iron overload. Disruption of intestinal HIF-2a or limiting iron intake by dietary iron restriction in SCD mice, significantly reduced systemic iron overload, lowered cellular sickle hemoglobin, and consequently improved hemolysis and ameliorated anemia. Our lab previously demonstrated that microbial signals from the gut also participated in initiation of VOE and organ damage in SCD mice. To elucidate connections between dietary iron, the microbiota-gut axis, and SCD pathogenesis, we hypothesize that dietary iron restriction may reduce microbiota load and gut permeability, and contributes to amelioration of acute and chronic complications in SCD mice. Methods: SCD mice were generated by transplanting bone marrow cells from Berkeley SCD (Tg[Hu-miniLCRα1GγAγδβS]Hba−/− Hbb−/−) mice into 8-week old, lethally-irradiated C57BL/6J mice. Immediately after transplantation, SCD mice were fed either a regular-iron diet (Ctrl) containing 185 parts per million (ppm) iron or an otherwise identical iron-restricted diet (IRD) containing 3 ppm iron. VOE and organ damage analysis were conducted 3-4 months after treatments. Results: IRD resulted in a reduced organ iron concentration in SCD compared to Ctrl group(0.6±0.1 v.s. 4.0±0.7ug iron/mg liver tissue; P=0.001), confirming that dietary iron restriction reverses organ iron deposition in SCD mice. SCD mice treated with IRD exhibited reduced MCHC (19.7±0.3 v.s. 20.1±0.2 pg; P=0.006) and serum indirect bilirubin (0.4±0.04 v.s. 0.7±0.07 mg/dL; P=0.001) indicating a decrease in cellular sickle hemoglobin and hemolysis. Furthermore, IRD reduced the fraction of aged neutrophils by >50% in SCD mice which corresponded with improved VOE parameters (RBC velocity: 2.0±0.2 v.s. 1.6±0.1mm/s; P=0.01; blood flow rate: 314±33 v.s. 230±13pL/s; P=0.01; leukocyte adhesion: 10±1 v.s. 14±1cells/100um vein; P=0.01; IRD v.s. Ctrl). Importantly, IRD led to prolonged survival after TNF-a challenge in SCD mice (Fig1). IRD resulted in a dramatic reduction in lung leukocyte infiltration, indicating significantly reduced lung inflammation in SCD mice (Fig2A). Compared to Ctrl liver samples, IRD resulted in significantly less liver necrosis, leukocyte infiltration and fibrosis (Fig2B). We further hypothesized that, in addition to reducing iron concentration in organs, IRD ameliorates organ damage by preventing translocation of microbial compounds. Microbiota load in IRD treated SCD mice were decreased to 25% of Ctrl level. IRD inhibited translocation of FITC-Dextran by 5-fold compared to Ctrl suggesting functionally improved gut permeability. We detected significantly decreased TLR2 ligands in serum of IRD compared to Ctrl mice (0.31±0.04 v.s. 0.46±0.05 TLR2 ligand activities O.D. 650nm; P=0.04) suggesting ligands from gram-positive bacteria (TLR2 agonists) may play a role in triggering SCD complications. Conclusion: Our study demonstrates first time that dietary iron restriction reduces VOE severity and alleviates chronic organ damage in SCD mice. These findings provide strong evidence for the therapeutic potential of manipulating iron homeostasis and the gut microbiome to ameliorate SCD pathophysiology. Many treatments under development focus on lowering the systemic iron concentration to relieve disease complications, and our data suggest that iron-induced changes in microbiota load and gut integrity are related and novel therapeutic targets. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Magnetic Fractionation of Red Blood Cells Based on Oxygen Saturation in Sickle Cell Disease

Anemias are a broad classification of red blood cell (RBC) disorders which effectively result in inadequate oxygen transport in the body. Sickle Cell Disease (SCD) results from a point mutation in hemoglobin, and the hemoglobin-oxygen equilibrium becomes right shifted (i.e., SCD RBCs do not oxygen saturate to the same degree as healthy RBCs). RBC exchange transfusion is a common clinical practice to increase the oxygen carrying capacity of a SCD patient - a process by which the patient's own RBCs are exchanged with healthy donor blood. During this process, large amounts of donor RBCs are discarded along with the patients SCD RBCs. Here we present a new RBC separation modality based on hemoglobin-oxygen equilibrium.It is well known that RBCs become magnetized as a function of the oxygen saturation of its hemoglobin. Due to the difference in hemoglobin-oxygen equilibrium for healthy and SCD RBCs we demonstrate a magnetic method of fractionating RBCs based on oxygen saturation. In our study, we use the SCD transfusion waste product and sort this sample into healthy fractions and SCD fractions using a field flow permeant magnetic separator. Under variable oxygen tension of the sample, we preformed the magnetic sorting.By incorporation of magnetic separation into RBC exchange processes, more efficient selection, and removal of SCD RBCs can be accomplished. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

PI-10: DIETARY IRON RESTRICTION PROTECTS AGAINST VASO-OCCLUSION AND ORGAN DAMAGE IN SICKLE CELL DISEASE

Purpose: Sickle cell disease (SCD) is the most commonly inherited monogenic hemoglobinopathy and results from a mutation in the β-globin gene (HbS), leading to red blood cell (RBC) sickling, vaso-occlusive episodes (VOE), and organ damage. Chronic hemolysis, inflammation, and repeated red blood cell transfusions in SCD can disrupt iron homeostasis. Patients who receive multiple blood transfusions develop iron-overload, and another subpopulation of SCD patients manifest iron deficiency. SCD mice exhibit increased iron absorption via upregulation of the intestinal transcription factor hypoxia inducible factor-2a(HIF-2a) leading to the development of iron overload. Disruption of intestinal HIF-2a or limiting iron intake by dietary iron restriction in SCD mice, significantly reduced systemic iron overload, lowered cellular sickle hemoglobin as reflected by reduced RBC mean corpuscular hemoglobin concentration (MCHC), and consequently improved hemolysis and ameliorated anemia. Understanding iron homeostasis is therefore critical to SCD pathogenesis and holds the promise for identifying novel approaches to treat SCD. Materials and methods: SCD mice were generated by transplanting bone marrow cells from Berkeley SCD (Tg[Hu-miniLCRα1GγAγδβS]Hba−/− Hbb−/−) mice into 8-week old, lethally-irradiated C57BL/6J mice. Immediately after transplantation, SCD mice were fed either a regular-iron diet (Ctrl) containing 185 parts per million (ppm) iron or an otherwise identical iron-restricted diet (IRD) containing 3 ppm iron. VOE and organ damage analysis were done 3-4 months after treatments. Results: IRD resulted in a reduced organ iron concentration (Fig-1A) in SCD compared to Ctrl group, confirming that dietary iron restriction ameliorates organ iron deposition in SCD mice. SCD mice treated with IRD exhibited reduced MCHC (Fig-1B) and serum indirect bilirubin(IDBILC) (Fig-1C) indicating a decrease in cellular sickle hemoglobin and hemolysis. Furthermore, IRD reduced the fraction of aged neutrophils by >50% in SCD mice (Fig-1D), which corresponded with improved VOE parameters. Specifically, intravital microscopy (IVM) demonstrated elevated mean centerline RBC velocity and blood flow rate and decreased leukocyte adhesion in IRD compared to Ctrl mice (Fig-1E-G). Importantly, IRD led to prolonged survival after TNF-a challenge in SCD mice (Fig-1H). IRD resulted in a dramatic reduction in lung leukocyte infiltration, indicating significantly reduced lung inflammation in SCD mice (Fig-2A). Compared to Ctrl liver samples, IRD resulted in significantly less liver necrosis, leukocyte infiltration and fibrosis (Fig-2B,C), decreased serum liver enzymes (ALT, AST; Fig-2D), and reduced levels of total and direct bilirubin (TBILC, DBILC; Fig-2D).We further hypothesized that, in addition to reducing iron concentration in organs, IRD ameliorates organ damage by preventing translocation of microbial compounds.IRD inhibits translocation of FITC-Dextran by 5-fold compared to Ctrl suggesting functionally improved gut permeability (Fig-2E). We detected significantly decreased TLR2 ligands in serum of IRD mice (Fig-2F) suggesting ligands from gram-positive bacteria (TLR2 agonists) may play a role in triggering SCD complications. Conclusion: Our study demonstrates for the first time that dietary iron restriction reduces VOE severity and alleviates chronic organ damage in SCD mice. Novel approaches that target iron availability/absorption in the gut, the gut microbiome and aged neutrophil crosstalk and gut barrier integrity, provide an important area of further investigation with the potential of improving hemolysis, VOE, and organ damage in SCD patients.(A)The bone-marrow/spleen/liver Non-heme iron content. (B)MCHC, (C)IDBILC,(D)aged neutrophils percentage in Ctrl/IRD SCD mice. IVM parameters (E) (Vrbc) (F) blood flow rate (J) the number of adherent leukocytes and (J) survival rate after TNF-a injection(A)Leukocyte infiltration in lung and (B)liver tissue. (C)Liver necrosis, leukocyte infiltration, and fibrosis. (D)Liver ALT and AST, TBILC, and DBILC from sera. (E)serum FITC-Dextran and (F) TLR2 ligands activity in Ctrl/IRD SCD mice The authors do not declare any conflict of interest

S299: ROLE OF RED BLOOD CELL MEMBRANE-DERIVED PARTICLES ON ENDOTHELIAL DAMAGES DURING ONSET STAGE OF DELAYED HEMOLYTIC TRANSFUSION REACTION

Background: Delayed hemolytic transfusion reaction (DHTR) is a life-threatening complication of red blood cell (RBC) transfusion in sickle cell disease (SCD) patients, leading to the increase of plasma hemoglobin (Hb) and heme which are responsible for endothelial damage and organs failure. By the development of an in vitro model reproducing endothelial damages at the early phase of DHTR (Nguyen et al, ASH 2018), our previous study suggested that RBC membrane-derived particles released during the onset stage of DHTR could be also involved in DHTR physiopathology. Aims: In this study, we aim to determine the mechanism of endothelial damages induced by these RBC particles. Methods: Human Umbilical Vein Endothelial Cells (HUVECs) cultured in flow condition for 24 hours were perfused by either serum only (decomplemented or not) or serum containing either whole hemolysate (sonicated RBCs) or different hemolysate components or RBCs membranes (ghosts) under shear stress 1 dyne/cm2. Annexin V and Eculizumab were used for complement studies. Endothelial activation and damages were assessed by membrane CD54 (PECAM-1, Platelet endothelial cell adhesion molecule 1), CD106 (VCAM-1, Vascular Cell Adhesion Molecule-1) and actin network staining. The whole blood adhesion assays and platelets aggregation study on hemolysate-preconditioned HUVECs were performed in continuous flow. Confocal microscopy was used to study interaction between HUVECs and hemoglobin (Hb) and RBC membrane-derived particles. Results: Our fluidic model reproduced a hemolysate-induced pro-inflammatory phenotype and damages of HUVECs via NFkB signaling pathway in a TLR-4 independent manner. The most deleterious effects were observed in whole hemolysate conditions in which, an important quantity of RBC large-size particles (> 2 μm) mostly positive for C3 was detected. These effects on HUVECs were significantly reduced after their elimination by 14000 g centrifugation (Figure 1). Noteworthy, the suspension of ghosts induced a similar activation on HUVECs compared to whole hemolysate suggesting the major role of RBC membrane-derived particles in early hemolysis-induced endothelial damages. Confocal microscopy for intracellular compartment of hemolysate-treated HUVECs demonstrated that while the CD235a+ Hb+ particles were only found in whole hemolysate conditions, the Hb was detected similarly in all conditions tested. Selective blocking of RBCs particles and Hb endocytosis did not affect hemolysate-induced HUVECs activation. These observations demonstrate that in the very early stage (≤4H) of intravascular hemolysis, erythrocytes large-size particles can be internalized in HUVECs, but their internalization is not necessary for endothelial activation effect. Complement inactivation of serum or treatment of RBC particles by either Annexin V or Eculizumab could reduced their effects on endothelial activation suggesting a complement-dependent mechanism Image:Summary/Conclusion: This study suggested for the first time the major role of RBCs large-size particles on endothelial damages at the onset of DHTR in a complement-dependent manner justifying the complement blocking treatment in certain DHTR patients. Furthermore, we have also demonstrated the endocytosis of free Hb by HUVECs, but its pathological impact is still unclear. This endocytosis would facilitate the Hb clearance during a massive hemolysis? These new understandings will allow a better and earlier management to preserve endothelial functions.

Preclinical evaluation of the preservation of red blood cell concentrates by hypoxic storage technology for transfusion in sickle cell disease.

Not available.

Pregnancy outcomes with hydroxyurea use in women with sickle cell disease.

Hydroxyurea reduces pain crises, acute chest syndrome, and blood transfusions in sickle cell disease (SCD), but potential detrimental effects on fertility and birth outcomes impede its use. Data on the effects of hydroxyurea taken for SCD during conception and pregnancy are scarce. The Sickle Cell Disease Implementation Consortium collected self-reported pregnancy history, corresponding hydroxyurea use, and pregnancy outcomes in women with SCD in the clinical setting. Among 1285 women 18-45 years of age, 737 (57.4%) reported 1788 pregnancies (1079 live births, 394 miscarriages, 40 stillbirths, 207 abortions, 48 current pregnancies, and 20 missing outcomes) of which 241 (15.9%) live births, miscarriages or stillbirths were conceived while on hydroxyurea. In univariate analyses, pregnancy number more than three, severe sickle genotype, history of stillbirth or miscarriage, and chronic kidney disease at enrollment were covariates significantly associated with a pregnancy ending in miscarriage or stillbirth. After adjustment for covariates and additional SCD severity markers in multivariate analyses, hydroxyurea use during conception and pregnancy, but not during conception only, was associated with an increase in the odds ratio (OR) of miscarriage or stillbirth (OR 2.21, 95% confidence interval [CI] 1.40-3.47). In analyses of live birth outcomes, hydroxyurea use during conception and pregnancy was associated with birth weight < 5.5 pounds in full-term infants (OR 2.98, 95% CI 1.09-7.38) but not with prematurity or serious medical problems at birth. These findings suggest that hydroxyurea use may be safe up to the time of conception, but that clinicians should continue to advise caution regarding use during pregnancy.

Glucose-6-phosphate dehydrogenase deficiency is more prevalent in Duffy-null red blood cell transfusion in sickle cell disease.

Resistance to malaria infection may be conferred by erythrocyte genetic variations including glucose-6-phosphate dehydrogenase (G6PD) deficiency and lack of Duffy antigens. In red blood cell (RBC) transfusion, G6PD deficiency may shorten transfusion survival. Because Duffy-null units are commonly transfused in sickle cell disease (SCD) due to antigen matching protocols, we examined whether Duffy-null donor RBC units have a higher prevalence of G6PD deficiency. Pediatric patients with SCD on chronic transfusion therapy were followed prospectively for multiple transfusions. RBC unit segments were collected to measure G6PD activity and RBC genotyping. The decline in donor hemoglobin (ΔHbA) following transfusion was assessed from immediate posttransfusion estimates and HbA measurements approximately 1month later. Of 564 evaluable RBC units, 59 (10.5%) were G6PD deficient (23 severe, 36 moderate deficiency); 202 (37.6%) units were Duffy-null. G6PD deficiency occurred in 40 (19.8%) Duffy-null units versus 15 (4.5%) Duffy-positive units (p < .0001). In univariate analysis, the fraction of Duffy-null RBC units per transfusion was associated with greater decline in HbA (p=.038); however, in multivariate analysis, severe G6PD deficiency (p=.0238) but not Duffy-null RBC (p=.0139) were associated with ΔHbA. Selection of Duffy-null RBC units may result in shorter in vivo survival of transfused RBCs due to a higher likelihood of transfusing units from G6PD deficient donors.

Choosing Non-Malignant Hematologic Care Wisely: An Educational Pilot Study for Internal Medicine Residents

Introduction: Choosing Wisely ® (CW ®)is an initiative of the American Board of Internal Medicine Foundation created to guide the selection of care that is 1) supported by evidence, 2) not duplicative, 3) free from harm, and 4) truly necessary. Between 2013-14, the American Society of Hematology (ASH) published 10 recommendations in accordance with CW ® principles relevant to hematologic care. Previous studies have demonstrated that clinical exposure to non-malignant hematology (NMH) improves trainee understanding of evidence-based, cost effective care as outlined by ASH CW ®. However, dedicated clinical rotations in NMH for internal medicine (IM) residents are not consistently available. Therefore, we created a condensed educational curricular experience using a small group, case-based structure designed to teach the fundamentals of ASH CW ® in NMH to first year IM residents. With a pilot of 6 sessions, we investigated resident baseline knowledge, evaluated the curricular session, and assessed knowledge retention.Methods: The educational intervention focused on 3 content areas in ASH CW ®: venous thromboembolism (VTE), heparin-induced thrombocytopenia (HIT), and sickle cell disease (SCD) (Table 1). Participants included 21 first year IM residents at a large academic medical center. A 1-hour small group teaching session was scheduled monthly as an assigned didactic for the 2020-21 academic year. A total of 6 sessions were provided, and each session had 2-4 residents assigned. The first 4 sessions were in-person and the final 2 were virtual due to the COVID-19 pandemic. The first author was the instructor at all sessions.To assess baseline knowledge of the 3 content areas, participants completed an online assessment with 5 case-based multiple-choice questions at the beginning of the session. The instructor then guided participants to again complete the questionnaire together, now using internet access via a personal computer and a recommended list of online resources, including ASH Clinical Practice Guidelines and Pocket Guides. The instructor then led discussion on how each correct answer or guideline recommendation achieves the 4 CW ® principles. At the conclusion of the session, participants completed an online survey to evaluate the educational intervention using a modified Likert scale. To assess knowledge retention, participants received the original online multiple-choice assessment by email 3 months later.Results: All participants (21/21, 100%) completed the baseline knowledge assessment. The average number of questions correct out of 5 total was 3.3 (67%), with a range of correct answers from 1 to 5. Table 2 includes the content area of each question and the number of correct responses. The question with the lowest total correct (9/21, 43%) addressed the use of transfusion in an uncomplicated pain crisis in SCD.Seventeen participants (81%) completed the curricular evaluation. All respondents (17/17, 100%) either agreed or strongly agreed 1) that the session filled a gap in their NMH training and 2) that they learned something that would change their clinical practice. Only 1 participant (5%) reported completing a rotation in NMH prior to the session.Six participants (29%) completed the repeat knowledge assessment at 3 months. All respondents (100%) achieved a perfect score on the multiple choice questions. When asked if the knowledge gained had influenced their clinical practice, 3 (50%) strongly agreed, 2 (33%) agreed, 1 (17%) was neutral, and none disagreed or strongly disagreed.Conclusion: Our results demonstrate a successful educational pilot to improve the knowledge of ASH CW ® initiatives in NMH for first year IM residents using small group interactive case-based learning. Participants were overwhelmingly receptive to this intervention, expressed high satisfaction and confirmed that the session positively influenced their clinical practice. Although participation in the repeat assessment of knowledge was limited, those that did participate demonstrated high knowledge retention. We intend to expand this pilot initiative by providing the educational session for all incoming IM residents at our institution. We then plan to assess its impact on clinical practice (i.e. use of transfusion in SCD, use of thrombophilia testing, documentation of 4Ts score calculation) to apply the principles of ASH CW ® for improved patient care. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Epidemiology and Predictors of Blood Transfusion in Hospitalizations for Sickle Cell Disease

Background: Transfusional iron overload contributes to considerable morbidity and mortality in patients with sickle cell disease. Despite FDA (Food and Drug Administration) approval of voxelotor in 2019, it remains underutilized, and RBC (red blood cell) transfusions play a prominent role in managing these patients. Contemporary large-scale epidemiologic data on blood transfusions in sickle cell disease are lacking. This study reports demographics, readmission rate, and factors associated with blood transfusion in hospitalizations for sickle cell disease.Methods: We performed a retrospective cohort study using the Nationwide Readmissions Database (NRD) for 2017 & 2018 to identify hospitalizations with the primary diagnosis of sickle disease using appropriate ICD-10-CM (International Classification of Diseases, Tenth Revision, Clinical Modification) codes. These admissions were categorized into those who received blood transfusions and those without blood transfusions. We performed descriptive analysis to compare demographics, hospital characteristics, various comorbid conditions, and complications between the two groups. All-cause 30-day readmission rate was calculated after excluding index admissions from December, deaths during index admissions, and elective readmissions. Multivariable logistic regression was used to adjust for confounders and determine factors associated with RBC transfusion. The analysis was carried out to produce national estimates after applying weights, and the methodology provided by the HCUP (Healthcare Cost and Utilization Project) was utilized.Results: Out of 109,783 weighted index hospitalizations, 28,300 were transfused, and 81,483 were not transfused. The proportion of females and 40 years & older was higher in the transfused category than not transfused (59.49% vs. 53.52% and 28.86% vs. 21.27% respectively; p<0.001 for both). The wealthiest population was more likely to be in the transfused category than the non-transfused (11.27% vs. 8.34%; p<0.001). The proportion of admissions to teaching hospitals, large metropolitan hospitals, and highest volume hospitals was higher in the non-transfused category compared to the transfused (79.89% vs. 72.17%; p<0.001, 69.26% vs. 65.35%; p 0.003 and 74.71% vs. 63.51%; p<0.001 respectively). The comorbidity burden, mean length of stay, total hospital charges, and inpatient mortality were higher in the transfused category than those without transfusion (table 1). Most admissions were transfused once, with multiple transfusions (3 or more) being given more in the non-teaching hospitals than teaching (1.27% vs. 0.41%; p 0.01). Furthermore, more than half of all transfusions happened within the first two days of admission, with a higher proportion of early transfusions in the non-teaching hospitals compared to teaching hospitals (65.6% vs. 57.82% for admission days 1 and 2; p<0.001) (table 2). Age group ≥40 years and 25-39 years were more likely to receive transfusion in the first two days of admission than the 18-24-year-olds (69.01% vs. 59.14% vs. 49.2%; p<0.001 respectively). After adjusting for confounders, older age groups (age ≥40 years and 25-39 years) compared to 18-24-year-olds (aOR {adjusted odds ratio} 1.48; 95% CI {confidence interval} 1.36-1.62 and aOR 1.21; 95% CI 1.12-1.31 respectively), female sex (aOR 1.23; 95% CI 1.17-1.31), highest community-level income (aOR 1.52; 95% CI 1.31-1.75), admission to rural hospital (aOR 1.82; 95% CI 1.26-2.6), length of stay 4-7 vs. ≤3 days (aOR 1.56; 95% CI 1.46-1.66) and length of stay ≥8 vs. ≤3 days (aOR 2.28; 95% CI 2.05-2.53) were found to be associated with higher odds of blood transfusion. Admission to a teaching hospital was associated with lower blood transfusion odds than a non-teaching hospital (aOR 0.70; 95% CI 0.56-0.87) (table 3).Conclusion: A quarter of admissions for sickle cell disease receive a blood transfusion. In addition to performing more frequent and early transfusions, the odds of being transfused are higher in a non-teaching hospital. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Extended phenotyping does not preclude the occurrence of delayed haemolytic transfusion reactions in sickle cell disease.

Delayed haemolytic transfusion reaction (DHTR) is a potentially life-threatening complication of red blood cell (RBC) transfusions in sickle cell disease (SCD) and is classically induced by reactivation of previously formed antibodies. Improved antigenic matching has reduced alloimmunization and may reduce DHTR risk. We conducted a retrospective cohort study to investigate the incidence rate of DHTR in SCD patients receiving extended matched units (ABO/RhDCcEe/K/Fya /Jkb /S). Occasional transfusion episodes (OTE) between 2011 and 2020 were reviewed for occurrence of DHTR symptoms using four screening criteria: decreased Hb, increased lactate dehydrogenase (LDH), pain, and dark urine. We included 205 patients who received a cumulative number of 580 transfusion episodes of 1866 RBC units. During follow-up, 10 DHTR events were observed. The incidence rate of DHTR was 13·8/1000 OTEs [95% confidence interval (CI): 7·37-22·2], with a cumulative incidence of 15·2% (95% CI: 8·4-24·0%) after 25 patients having received RBC units. One DHTR event was fatal (10%). Symptoms were misdiagnosed in four DHTR events (40%) as other acute SCD complications. Despite a lower incidence rate compared to most other studies, the incidence rate of DHTR in SCD remains high, in spite of extended matching of donor RBCs. Increased awareness of DHTR is of utmost importance to facilitate early diagnosis and, consequently, improve outcome.

Guidelines for the monitoring and management of iron overload in patients with haemoglobinopathies and rare anaemias.

Guidelines for the monitoring and management of iron overload in patients with haemoglobinopathies and rare anaemias.

Impact of universal irradiation on chronic transfusion for sickle cell disease.

Irradiation of blood products prevents transfusion-associated graft-versus-host disease, but most patients do not require this modification which could have an adverse impact on transfusion outcomes. We hypothesized that irradiation may increase transfusion requirements for patients with sickle cell disease (SCD) receiving chronic transfusion. Our pediatric hospital implemented a new policy of universal blood product irradiation in May 2018. We conducted a retrospective chart review of patients with SCD receiving chronic red blood cell (RBC) transfusion throughout the year before and after institution of this policy. The primary outcome was the change in RBC transfusion volume per patient weight transfused during the pre- vs. post- universal irradiation period. Secondary outcomes were the change in median pretransfusion laboratory values. Among 17 patients, 8 (47%) received more RBCs the year before irradiation and 9 (53%) received more the year after irradiation. Implementation of universal irradiation did not significantly increase transfusion volumes needed to clinically manage this population (median change +1.7ml/kg/year, p= .54). Additionally, there were no significant changes in absolute reticulocyte count, hemoglobin, hemoglobin S%, white blood cell count, lactate dehydrogenase, total bilirubin, serum potassium, and ferritin during the two time periods. In a cohort of patients with SCD receiving simple chronic transfusion, irradiation did not impact transfusion requirements or pertinent pretransfusion laboratory values. Irradiation does not appear to have clinically significant consequences for SCD chronic transfusion management.

Sickle Cell Disease and the Adherence to Guidelines for Use of Blood Transfusions

▪Background:An expert panel convened by the NHLBI in 2014 provided guidelines and indications for blood transfusions in patients with sickle cell disease (SCD). These recommendations were to help conserve the use of blood transfusions in SCD in order to reduce the complications of iron overload, transmission of blood-borne pathogens and development of alloantibodies. We retrospectively reviewed the charts of SCD patients who received blood during inpatient admissions and evaluated the indications for transfusions in this population.Methods:The hospital database was screened for admissions of patients with the diagnosis of SCD (HbSS, HbSβ0, HbSβ+, HbSC) who were billed for a blood transfusion between 8/1/2015 to 8/31/2016. All patients were >18 years of age. Each chart was reviewed individually to assess the clinical setting and reasons for transfusion. The following parameters were documented: age, sex, length of hospital stay (LOS), hemoglobin (Hgb) at time of transfusion, baseline Hgb, reticulocyte count, total bilirubin, number of units transfused, documented reason for transfusion, immediate reaction to transfusion, presence of alloantibodies and ferritin level. We defined the infusion of blood as a transfused event which included single or multiple units of blood. We excluded transfusions given for acute bleeding.Results:There were a total of 200 decisions to transfuse blood for 87 patients between 8/1/2015 to 8/31/2016. 72% of the patients had HbSS disease. HbSB0, HbSB+, HbSC, and unknown genotype constituted 14%, 19%, 6% and 7% of the cohort, respectively. Mean age was 30.6 years and 76% were female. A total of 434 units were transfused. The most common reasons for transfusion that deviated from guidelines were uncomplicated pain crises and a fall in Hgb (> 2g/dl, >1.5 g/dl) which accounted for 65.5% (n = 237 units) of the transfusion events (Pain 27%, Hgb drop > 2 gm 20.5% and Hgb drop > 1.5 gm 17.5%). The most common indicated guideline reasons for transfusion were symptomatic anemia and acute chest syndrome and only accounted for 12.5% and 10%, respectively of transfusions in this cohort. The mean Hgb at which patients were transfused was 6.6 g/dl, with a median value of 6.5 g/dl. The mean Hgb of those transfused for drop in hemoglobin and symptomatic anemia were 5.9 g/dl and 5.7 g/dl, respectively. The mean level of ferritin in this cohort was 2483. 15/87(17%) of patients had allo-antibodies. There was a 2% occurrence of immediate allergic blood transfusion reaction. The average LOS for all patients was 9.0 days. The average LOS for patient who received blood for uncomplicated pain or drop in Hgb was 8.9 days.Conclusion:In this group of patients with SCD, the majority of the inpatient transfusions were not indicated by national guidelines. Only 34.5% of transfusion events met expert panel recommendations. There was significant iron overload and development of allo-antibodies noted in our cohort. It is possible that there was a lack of documentation of symptoms due to anemia in those who received blood for a drop in hemoglobin. Regardless, there appears to be a significant number of unnecessary transfusions in SCD patients. We plan to develop and implement an educational program for care providers as to increase adherence to guidelines for transfusions in SCD. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Rejuvenated RBCs Increase Oxygen Consumption in a Simulated Exchange Transfusion Model of Sickle Cell Disease Patients

Introduction: Exchange transfusion of red blood cells (RBCs) in patients with Sickle Cell Disease (SCD) may require 6 to 8 units to reduce sickle hemoglobin (Hb-S) to less than 30 percent of total hemoglobin (NIH No. 02-2117). Low oxygen affinity (high p50) in patients with SCD is manifested by impaired blood viscosities and reduced hemoglobin concentration. Well characterized RBC metabolic changes during liquid storage of donor RBC include an increase in the affinity of hemoglobin for oxygen (low p50) by depletion of 2,3-diphosphoglycerate (2,3-DPG). Transfusion of stored RBCs (Standard RBC) suggests inefficient and impaired O2 delivery to tissues compared to fresh circulating RBCs (Hasan 1994, Scott 2016) or after exchange transfusion in SCD (Uchida 1998). Extracorporeal manipulation of p50 through RBC rejuvenation increases the level of 2,3-DPG and increases the p50 of stored RBCs by right-shifting the Oxyhemoglobin Dissociation Curve (ODC) (Dennis 1979). Rejuvenation occurs by incubating RBCs at 37 °C for 60 minutes with a rejuvenation solution (Citra Labs). An exchange transfusion simulation model was developed to evaluate the changes in oxygen release capacity of rejuvenated RBCs and the potential impact on estimated oxygen consumption (VO2) compared to Standard RBCs.Methods: Oxyhemoglobin dissociation curves were generated from (5) RBC units (leukocyte-reduced), CPD/AS-1, on Day 0, after 21 days of storage (Standard RBC), and after rejuvenation on day 21 (REJ RBC) which were used to estimate p50 values of the donor/recipient mixtures after each exchange transfusion and to determine VO2 as previously described (Li 2016, Srinivasan 2017). An elevated p50 of 30.4 mm Hg, typical for SCD patients (Uchida 1998), was used to estimate the baseline VO2 (200 mL O2/min). VO2 was determined after each simulated RBC exchange with Standard or REJ RBCs assuming a constant blood volume of 5L, cardiac output of 5 L/min, total hemoglobin concentration of 10 g/dL. The model assumed an exchange rate of one apheresis unit of circulating RBCs to transfusion of one unit of Standard or REJ RBCs.Results: Donor RBC p50 was 26.9 ± 2.0 mm Hg on Day 0 and declined with storage to 17.6 ± 1.5 mm Hg at 21 days (p < 0.001, t-test). Rejuvenation restored p50 to 34.8 ± 2.7 mm Hg which was significantly higher than Day 0 (p < 0.001, t-test). The model predicted a reduction in Hb-S from 70 % to 22%, a decrease in p50 after the 8 unit exchange transfusion to 21.6 mm Hg with Standard RBC, but an increase in p50 to 33.3 mm Hg with REJ RBC (Figures 1a & 1b). Similarly, VO2 increased in the REJ RBC group but decreased sequentially with Standard RBC upon each additional exchange transfusion (Figure 1c). The model predicted a decrease in VO2 to 118 mL O2/min for the Standard RBC group and an increase to 233 mL O2/min with REJ RBC group after the exchange transfusion.Conclusions: The model predicted a baseline VO2 of 200 mL O2/min; however, in fresh whole blood from healthy volunteers with Hb-A, normal VO2 was estimated at 244 mL O2/min (Srinivasan 2017). This simulation suggested that performing an exchange transfusion with REJ RBCs could achieve 95% of normal oxygen consumption assuming a constant cardiac output even though the hemoglobin was maintained at 10 g/dL. While exchange transfusion has been a successful therapy to reduce the Hb-S percentage in chronically transfused SCD patients, improving tissue oxygen exchange may not yet be optimized as evidenced by post transfusion declines in p50 (Miller 1980, Uchida 1998). The model is limited because it does not account for improved rheological properties and blood viscosity following exchange transfusion, which was previously reported to improve exercise capacity even though p50 declined (Miller 1980). The model also did not account for any influence from irreversibly sickled cells. Transfusion practices to correct anemia and improve tissue oxygenation may be less effective than intended due to the diminished oxygen release capacity of standard stored RBC units. Transfusion strategies should consider whether the use of RBCs with increased p50 may be physiologically advantageous.Figure 1: Predicted ODC (a) before and after the simulated exchange transfusion with Standard or REJ RBCs and predicted Hb-A vs Hb-S ratios (b) and VO2 (c) after each unit of the exchange transfusion with Standard or rejuvenated RBCs. [Display omitted] DisclosuresKausch:Zimmer Biomet: Employment, Research Funding. Gray:Zimmer Biomet: Employment, Research Funding. Landrigan:Zimmer Biomet: Employment, Research Funding.

Hyperhemolysis Syndrome in a Patient with Sickle Cell Disease: A Case Report.

IntroductionHyperhemolysis syndrome (HHS) is a rare complication of repeat blood transfusions in sickle cell disease (SCD). This can occur acutely or have a delayed presentation and often goes unrecognized in the emergency department (ED) due to its rapid progression and similarity to acute chest syndrome and other common complications of SCD.Case ReportWe present a case of a 20-year-old male with SCD who presented to the ED with pain and tenderness in his lower extremities one day after discharge for a crisis. Unbeknownst to the ED team, during his admission he had received a blood transfusion. On presentation he was noted to have hyperkalemia, hyperbilirubinemia, anemia, and uncontrolled pain, and was admitted for sickle cell pain crisis. Over the next 36 hours, his hemoglobin dropped precipitously from 8.9 grams per deciliter (g/dL) to 4.2 g/dL (reference range: 11.5–14.5 g/dL), reticulocyte count from 11.7 % to 3.8% (0.4–2.2%), and platelets from 318,000 per cubic centimeter (K/cm3) to 65 K/cm3 (140–350 K/cm3). He also developed a fever, hypoxia, transaminitis, a deteriorating mental status, and severe lactic acidosis. Hematology was consulted and he was treated with methylprednisolone, intravenous immunoglobulin, two units of antigen-matched red blood cells, fresh frozen plasma, and cryoprecipitate. He was transferred to an outside hospital for exchange transfusion and remained hospitalized for 26 days with acute liver failure, bone marrow necrosis, and a fever of unknown origin.ConclusionBecause of the untoward outcomes associated with delay in HHS diagnosis and the need for early initiation of steroids, it is important for emergency providers to screen patients with hemoglobinopathies for recent transfusion at ED presentation. Asking the simple question about when a patient’s last transfusion occurred can lead an emergency physician to include HHS in the differential and work-up of patients with sickle cell disease complications.