Red cell transfusion and alloimmunization in sickle cell disease

Comparison of the Detection Rate and Specificity of Irregular Red Blood Cell Antibodies Between First-Time Pregnant Women and Women With a History of Multiple Pregnancies Among 18,010 Chinese Women

Background: There is insufficient evidence to assess the risk of the production of clinically important alloimmune irregular red blood cell (RBC) antibodies in first-time pregnant women. Methods: Using the microcolumn gel antiglobulin method, 18,010 Chinese women with a history of pregnancy and pregnant women were screened for irregular RBC antibodies, and for those with positive test results, antibody specificity was determined. The detection rate and specificity of irregular RBC antibodies in women with a history of multiple pregnancies (two or more) and first-time pregnant women were determined. Results: In addition to 25 patients who passively acquired anti-D antibodies via an intravenous anti-D immunoglobulin injection, irregular RBC antibodies were detected in 121 (0.67%) of the 18,010 women. Irregular RBC antibodies were detected in 93 (0.71%) of the 13,027 women with a history of multiple pregnancies, and antibody specificity was distributed mainly in the Rh, MNSs, Lewis, and Kidd blood group systems; irregular RBC antibodies were detected in 28 (0.56%) of the 4983 first-time pregnant women, and the antibody specificity was distributed mainly in the MNSs, Rh, and Lewis blood group systems. The difference in the percentage of patients with irregular RBC antibodies between the two groups was insignificant (χ 2 = 1.248, P > 0.05). Of the 121 women with irregular RBC antibodies, nine had anti-Mur antibodies, and one had anti-Dia antibodies; these antibodies are clinically important but easily missed because the antigenic profile of the reagent RBCs that are commonly used in antibody screens does not include the antigens that are recognized by these antibodies. Conclusion: Irregular RBC antibody detection is clinically important for both pregnant women with a history of multiple pregnancies and first-time pregnant women. Mur and Dia should be included in the antigenic profile of reagent RBCs that are used for performing antibody screens in the Chinese population.

Complex Transfusion Management in a Sickle Cell Patient With Anti-Fy3 Alloimmunization: A Case Report

Fy3 is a high-prevalence red blood cell antigen of the Duffy (Fy) blood group system. Anti-Fy3 antibodies are rare and solely arise in individuals with a Duffy null phenotype (Fy(a-b-)), which is a phenotype that mainly occurs in people of African descent. Clinically, anti-Fy3 antibodies can cause both acute and delayed hemolytic transfusion reactions in adults as well as hemolytic disease in fetuses and newborns. Here, we report the case of a 26-year-old male with sickle cell disease (SCD) and a history of anti-E alloantibodies, who was admitted to the hospital with a vaso-occlusive crisis (VOC) and associated low hemoglobin (Hb) level. For the latter he received one unit of antigen-matched and crossmatch-compatible packed red blood cells (pRBCs) without complications. Ten days later the patient was readmitted with a further VOC and associated low Hb level, again requiring a red cell transfusion. However, no crossmatch-compatible pRBCs could be identified. Laboratory testing demonstrated pan-reactivity with additional reference testing demonstrating the presence of anti-E, anti-Fy3 and anti-Jkb alloantibodies. This case highlights the diagnostic and therapeutic challenges associated with blood transfusion in SCD patients with rare alloimmunization profiles.

Decreasing alloimmunization-specific mortality in sickle cell disease in the United States: Cost-effectiveness of a shared transfusion resource

Red blood cell alloimmunization and consequent delayed hemolytic transfusion reaction (DHTR) incidence and mortality in patients with sickle cell disease (SCD) are high. A shared transfusion resource has decreased both in other countries, while in the United States cost concerns persist. We conducted a Markov cohort simulation of a birth cohort of alloimmunized patients with SCD to estimate lifetime DHTR incidence, DHTR-specific mortality, quality-adjusted life expectancy (QALE), and costs with the implementation of a shared transfusion resource to identify antibody history versus without (i.e., status quo). We conducted our analysis using a lifetime analytic time horizon and from a United States health system perspective. Implementation of shared transfusion resource projects to decrease cumulative DHTR-specific mortality by 26% for alloimmunized patients with SCD in the United States, relative to the status quo. For an average patient population of 32 000, this intervention would generate a discounted increment of 4000 QALYs at an incremental discounted cost of $0.3 billion, resulting in an incremental cost-effectiveness ratio of $75 600/QALY [95% credible interval $70 200-81 400/QALY]. The results are most sensitive to the baseline lifetime medical expenditure of patients with SCD. Alloantibody data exchange is cost-effective in 100% of 10 000 Monte Carlo simulations. The resource would theoretically need a minimum patient population of 1819 patients or cost no more than $5.29 million annually to be cost-effective. By reducing DHTR-specific mortality, a shared transfusion resource in the United States projects to be a life-saving and cost-effective intervention for patients with SCD in the United States.

RH genotypes and red cell alloimmunization rates in chronically transfused patients with sickle cell disease: A multisite study in the USA

BACKGROUND

Red cell alloimmunization remains a challenge for individuals with sickle cell disease (SCD) and contributes to increased risk of hemolytic transfusion reactions and associated comorbidities. Despite prophylactic serological matching for ABO, Rh, and K, red cell alloimmunization persists, in part, due to a high frequency of variant RH alleles in patients with SCD and Black blood donors.

STUDY DESIGN AND METHODS

We compared RH genotypes and rates of alloimmunization in 342 pediatric and young adult patients with SCD on chronic transfusion therapy exposed to >90,000 red cell units at five sites across the USA. Genotyping was performed with RHD and RHCE BeadChip arrays and targeted assays.

RESULTS

Prevalence of overall and Rh-specific alloimmunization varied among institutions, ranging from 5% to 41% (p = .0035) and 5%-33% (p = .0002), respectively. RH genotyping demonstrated that 33% RHD and 57% RHCE alleles were variant in this cohort. Patients with RHCE alleles encoding partial e antigens had higher rates of anti-e identified than those encoding at least one conventional e antigen (p = .0007). There was no difference in anti-D, anti-C, or anti-E formation among patients with predicted partial or altered antigen expression compared to those with conventional antigens, suggesting that variant Rh on donor cells may also stimulate alloimmunization to these antigens.

DISCUSSION

These results highlight variability in alloimmunization rates and suggest that a molecular approach to Rh antigen matching may be necessary for optimal prevention of alloimmunization given the high prevalence of variant RH alleles among both patients and Black donors.

Poverty and the wellbeing of children with sickle cell disease: The mediating role of parenting stress

BACKGROUND

Living in poverty in the midst of caring for a child with sickle cell disease (SCD) presents with challenges that may be overwhelming for caregivers. Prior research has shown a relationship between poverty and poor outcomes in children; however, no study has investigated the mediating role of parenting stress on health-related quality of life (HRQOL) for such children.

PROCEDURE

A total of 150 patients, ages 8-17 years and their parents, were enrolled and completed measures of parenting stress (caregivers) and HRQOL (patients). Caregivers also completed a demographic information questionnaire, which was used to determine poverty status. The Sobel test was used to analyze the association between poverty and HRQOL by way of parenting stress.

RESULTS

The series of linear regression results show poverty was a significant predictor for decreased HRQOL (B = -7.01, p = .05) among pediatric patients with SCD. Moreover, the regression coefficient measuring the indirect effect of the model measuring the mediating role of parenting stress was statistically significant (B = -1.05, p = .05).

CONCLUSION

The current study found an association between poverty status and HRQOL scores by way of parenting stress. Findings highlight the need for appropriate resource allocation to caregivers in addition to pediatric patients living with SCD.

Society for Maternal-Fetal Medicine Consult Series #68: Sickle cell disease in pregnancy

Pregnant individuals with sickle cell disease have an increased risk of maternal and perinatal morbidity and mortality. However, prepregnancy counseling and multidisciplinary care can lead to favorable maternal and neonatal outcomes. In this consult series, we summarize what is known about sickle cell disease and provide guidance for sickle cell disease management during pregnancy. The following are Society for Maternal-Fetal Medicine recommendations.

Robotic-assisted versus laparoscopic splenectomy in children: a costeffectiveness study

Laparoscopic elective splenectomy is considered as a safe surgical treatment of spleen non-traumatic blood disorders. However, robotic assisted splenectomy is becoming a promising alternative, although there are scarce studies in pediatric patients. Our aim is to compare the effectiveness and associated costs of both procedures in children. A single-institution retrospective study was performed among consecutive children undergoing splenectomy between 2004 and 2021, who were divided according to the surgical approach: LAS group (laparoscopic splenectomy) and RAS group (robotic assisted splenectomy). Demographics, clinical features, intraoperative blood loss, surgery time, length of hospital stay (LOS), postoperative complications, need for postoperative blood transfusion, readmission rate and economic data were compared. A total of 84 patients were included (23 LAS group; 61 RAS group), without demographic or clinical differences between them. RAS patients presented lower intraoperative blood loss (42 ± 15 vs. 158 ± 39 ml; p < 0.021) and shorter surgery time (135 ± 39 vs. 182 ± 68 min; p = 0.043), with no differences in median LOS (3 days in both groups). No intraoperative complications or conversion was reported. Five postoperative complications were observed: 4 in LAS patients (17.4%) versus only one in RAS (1.6%; p = 0.021). One reintervention was required in LAS group due to hemoperitoneum 12 h after splenectomy. RAS patients had lower postoperative blood transfusion requirements (1.6% vs. 13.0%; p = 0.025) and lower readmission rate (3.3 vs. 17.4%; p = 0.042). No differences were observed when comparing the median economic costs ($25,645 LAS vs. $28,135 RAS; p = 0.215). Robotic assisted splenectomy may be considered as a safe and feasible option in children compared to the traditional laparoscopic approach. Level of evidence: III.

Eleven years of alloimmunization in 6496 patients with sickle cell disease in France who received transfusion

ABSTRACT

Red blood cell (RBC) transfusion is a major therapy for sickle cell disease (SCD). Patients are at risk of forming antibodies to RBC antigens, which can result in the impossibility to find compatible units and can cause hemolytic transfusion reactions. This retrospective study investigates the evolution of RBC consumption and the frequencies, specificities, and chronology of the appearance of antibodies in a population of patients consistently receiving RH (C, D, E, c, e) and K-matched RBC units (RBCus) from a predominantly European donor population. Over the 11-year period in the Paris area, 6496 patients received transfusion at least once for a total of 239 944 units. Antibodies were made by 1742 patients. The first antibodies of a patient were predictive of subsequent immunization. By the 17th RBCu transfused (by the 20th, excluding warm autoantibodies), 75% of the patients who would make antibodies had made their first. By the 16th, 90% who would make antibodies to a high frequency antigen had made their first antibody to these antigens. Females made their first antibodies slightly earlier than males. Patients who received multiple transfusions (>50 units) had a higher immunization prevalence than those who rarely received transfusion (<12 units) but fewer clinically significant antibodies. Patients with SCD and prophylactic RH-K matching not immunized by the 20th RBCu are likely to have a low alloimmunization risk (to antigens other than RH-K), that is, be low responders, especially relative to the most clinically significant antibodies. This number of 20 units is a point before which close monitoring of patients is most important but remains open to future adjustment.

Overview of the Association Between the Pathophysiology, Types, and Management of Sickle Cell Disease and Stroke

Sickle cell disease (SCD) is a genetic blood disorder that affects hemoglobin and increases stroke risk, particularly in childhood. This review examines the pathophysiological association between SCD and stroke, the classification of stroke types, risk factors, diagnosis, management, prevention, and prognosis. A comprehensive literature search was conducted via PubMed, Scopus, and Cochrane databases. Relevant studies on SCD and stroke pathophysiology, classification, epidemiology, diagnosis, treatment, and prevention were identified. Sickle cell disease causes red blood cells to become rigid and sickle-shaped, obstructing blood vessels. Recurrent sickling alters cerebral blood flow and damages vessel walls, often leading to ischemic or hemorrhagic strokes (HS). These occur most frequently in childhood, with ischemic strokes (IS) being more common. Key risk factors include a prior transient ischemic attack (TIA), low hemoglobin, and a high leukocyte count. Neuroimaging is essential for diagnosis and determining stroke type. Primary prevention centers on blood transfusions and hydroxyurea for those at high risk. Acute treatment involves promptly restoring blood flow and managing complications. However, significant knowledge gaps remain regarding stroke mechanisms, optimizing screening protocols, and improving long-term outcomes. This review synthesizes current evidence on SCD and stroke to highlight opportunities for further research and standardizing care protocols across institutions. Ultimately, a holistic perspective is critical for mitigating the high risk of debilitating strokes in this vulnerable patient population.

Precision, integrative medicine for pain management in sickle cell disease

Sickle cell disease (SCD) is a prevalent and complex inherited pain disorder that can manifest as acute vaso-occlusive crises (VOC) and/or chronic pain. Despite their known risks, opioids are often prescribed routinely and indiscriminately in managing SCD pain, because it is so often severe and debilitating. Integrative medicine strategies, particularly non-opioid therapies, hold promise in safe and effective management of SCD pain. However, the lack of evidence-based methods for managing SCD pain hinders the widespread implementation of non-opioid therapies. In this review, we acknowledge that implementing personalized pain treatment strategies in SCD, which is a guideline-recommended strategy, is currently fraught with limitations. The full implementation of pharmacological and biobehavioral pain approaches targeting mechanistic pain pathways faces challenges due to limited knowledge and limited financial and personnel support. We recommend personalized medicine, pharmacogenomics, and integrative medicine as aspirational strategies for improving pain care in SCD. As an organizing model that is a comprehensive framework for classifying pain subphenotypes and mechanisms in SCD, and for guiding selection of specific strategies, we present evidence updating pain research pioneer Richard Melzack's neuromatrix theory of pain. We advocate for using the updated neuromatrix model to subphenotype individuals with SCD, to better select personalized multimodal treatment strategies, and to identify research gaps fruitful for exploration. We present a fairly complete list of currently used pharmacologic and non-pharmacologic SCD pain therapies, classified by their mechanism of action and by their hypothesized targets in the updated neuromatrix model.

O-negative blood shortage management in a university hospital: Impact of transfusing RhD-positive red blood cells to RhD-negative patients

BACKGROUND

Shortages of O-negative red blood cells are becoming increasingly common, forcing hospitals' blood transfusion services to find solutions to conserve this blood group for patients who need it most. The present study aimed to retrospectively evaluate the practice of transfusing selected RhD-negative patients with RhD-positive red blood cells and to assess the impact of this measure on patients and blood transfusion service management.

METHODOLOGY

Transfusion data of 1199 RhD-negative patients hospitalised at Cliniques Universitaires Saint-Luc between 2019 and 2022 were analysed. For patients who received RhD-positive red blood cells, age, gender, reason for hospital admission, indication for transfusion, and immunohematology analyses were recorded. These data enabled an assessment of transfusion practices over the years, characterisation of patients who received RhD-mismatched transfusions, determination of the alloimmunisation rate, and calculation of the total number of RhD-negative red blood cells saved.

RESULTS

During the study period, 141 RhD-negative patients received 604 RhD-positive red blood cells. A change in transfusion practices was observed over the years, with a greater proportion of RhD-negative patients being transfused with RhD-positive red blood cells in 2022 (28%) compared to 2019 (2%). The overall alloimmunisation rate was at least 20%, and 416 red blood cells were saved without any consequences. Patients undergoing cardiovascular surgery received the highest number of RhD-positive red blood cells.

CONCLUSION

The transfusion of selected RhD-negative patients with RhD-positive red blood cells is a low-risk practice that helps conserve RhD-negative red blood cells. However, there is a minimum 20% risk of alloimmunisation, which could have clinical and transfusion-related consequences in the future.

HLA-F and LILRB1 Genetic Polymorphisms Associated with Alloimmunisation in Sickle Cell Disease

Red blood cell (RBC) transfusion remains a critical component in caring for the acute and chronic complications of sickle cell disease (SCD). Patient alloimmunisation is the main limitation of transfusion, which can worsen anaemia and lead to delayed haemolytic transfusion reaction or transfusion deadlock. Although biological risk factors have been identified for immunisation, patient alloimmunisation remains difficult to predict. We aimed to characterise genetic alloimmunisation factors to optimise the management of blood products compatible with extended antigen matching to ensure the self-sufficiency of labile blood products. Considering alloimmunisation in other clinical settings, like pregnancy and transplantation, many studies have shown that HLA Ib molecules (HLA-G, -E, and -F) are involved in tolerance mechanism; these molecules are ligands of immune effector cell receptors (LILRB1, LILRB2, and KIR3DS1). Genetic polymorphisms of these ligands and receptors have been linked to their expression levels and their influence on inflammatory and immune response modulation. Our hypothesis was that polymorphisms of HLA Ib genes and of their receptors are associated with alloimmunisation susceptibility in SCD patients. The alloimmunisation profile of thirty-seven adult SCD patients was analysed according to these genetic polymorphisms and transfusion history. Our results suggest that the alloimmunisation of SCD patients is linked to both HLA-F and LILRB1 genetic polymorphisms located in their regulatory region and associated with their protein expression level.

Variant RHD alleles and Rh immunization in patients with sickle cell disease

RH diversity among patients and donors contributes to Rh immunization despite serologic Rh-matched red cell transfusions. Anti-D can occur in D+ patients with RHD variants that encode partial D antigens. Anti-D has also been reported in patients with conventional RHD transfused primarily with units from Black donors who frequently have variant RHD. We report 48 anti-D in 690 D+ transfused individuals with sickle cell disease, categorized here as expressing conventional D, partial D or D antigen encoded by RHD*DAU0. Anti-D formed in a greater proportion of individuals with partial D, occurred after fewer D+ unit exposures, and remained detectable for longer than for those in the other categories. Among all anti-D, 13 had clinical or laboratory evidence of poor transfused red cell survival. Most individuals with anti-D were chronically transfused, including 32 with conventional RHD who required an average of 62 D- units/year following anti-D. Our findings suggest that patients with partial D may benefit from prophylactic D- or RH genotype-matched transfusions to prevent anti-D. Future studies should investigate whether RH genotype-matched transfusions can improve use of valuable donations from Black donors, reduce D immunization and minimize transfusion of D- units to D+ individuals with conventional RHD or DAU0 alleles.

Human leukocyte antigen immunization in transfusion-dependent Moroccan patients with beta-thalassemia major: prevalence and risk factors

INTRODUCTION

Beta-thalassemia major patients need a regular blood transfusion to have an initial normal growth. However, these patients have an increased risk of developing alloantibodies. Our main goal was to study HLA alloimmunization in Moroccan Beta-thalassemia patients by confronting it with transfusion and demographic criteria, exploring the involvement of HLA typing profile in the development of HLA antibodies and in turn determining risk factors for their development.

METHODS

The study consisted of 53 Moroccan pediatric patients with Beta-thalassemia major. Screening for HLA alloantibodies was performed using Luminex technology Whereas HLA genotyping was done with sequence-specific primers (PCR-SSP).

RESULTS

In this study, 50.9% of patients have been identified as positive for HLA antibodies, with 59.3% having both HLA Class I and Class II antibodies. A significant increase frequency of DRB1*11 allele was revealed in non-immunized patients (34.6% vs. 0%, p = 0.001). Our results also revealed that the majority of our HLA immunized patients were women (72.4% vs. 27.6%, p = 0.001), and transfused with more than 300 units of RBC units (66.7% vs. 33.3%, p = 0.02). There were statistically significant differences when comparing these frequencies.

CONCLUSIONS

This paper revealed that the transfusion dependent Beta-thalassemia major patients are exposed to risk of developing HLA antibodies following transfusions with leukoreduced RBC units. The HLA DRB1*11 was a protective factor against HLA alloimmunization in our beta-thalassemia major patients.

Red blood cell alloantibodies in paediatric transfusion in sub-Saharan Africa: A new cohort and literature review

Blood transfusion support predisposes transfused children to the risk of erythrocyte alloimmunization in Sub-Saharan Africa. A cohort of 100 children receiving one to five blood transfusions were recruited for screening and identification of irregular antibodies using gel filtration technique. The mean age was 8 years and the sex-ratio at 1.2. The retrieved pathologies were: major sickle cell anaemia (46%), severe malaria (20%), haemolytic anaemia (4%), severe acute malnutrition (6%), acute gastroenteritis (5%), chronic infectious syndrome (12%) and congenital heart disease (7%). The children presented with haemoglobin levels ≤6 g/dl, and 16% of them presented positive irregular antibodies directed against the Rhesus (30.76%) and Kell (69.24%) blood group systems. A literature review shows that irregular antibody screenings vary from 17% to 30% of transfused paediatric patients in Sub-Saharan Africa. These alloantibodies are in particular directed against the Rhesus, Kell, Duffy, Kidd and MNS blood group and generally found in sickle cell disease and malaria. This study highlights the urgent need of extended red blood cell phenotyping including typing for C/c, E/e, K/k, and Fya/Fyb, and if possible Jka/Jkb, M/N, and S/s for children before transfusion in Sub-Saharan Africa.

Storage differentially impacts alloimmunization to distinct red cell antigens following transfusion in mice

INTRODUCTION

The impact of blood storage on red blood cell (RBC) alloimmunization remains controversial, with some studies suggesting enhancement of RBC-induced alloantibody production and others failing to observe any impact of storage on alloantibody formation. Since evaluation of storage on RBC alloimmunization in patients has examined antibody formation against a broad range of alloantigens, it remains possible that different clinical outcomes reflect a variable impact of storage on alloimmunization to specific antigens.

METHODS

RBCs expressing two distinct model antigens, HEL-OVA-Duffy (HOD) and KEL, separately or together (HOD × KEL), were stored for 0, 8, or 14 days, followed by detection of antigen levels prior to transfusion. Transfused donor RBC survival was assessed within 24 h of transfusion, while IgM and IgG antibody production were assessed 5 and 14 days after transfusion.

RESULTS

Stored HOD or KEL RBCs retained similar HEL or KEL antigen levels, respectively, as fresh RBCs, but did exhibit enhanced RBC clearance with increased storage age. Storage enhanced IgG antibody formation against HOD, while the oppositive outcome occurred following transfusion of stored KEL RBCs. The distinct impact of storage on HOD or KEL alloimmunization did not appear to reflect intrinsic differences between HOD or KEL RBCs, as transfusion of stored HOD × KEL RBCs resulted in increased IgG anti-HOD antibody development and reduced IgG anti-KEL antibody formation.

CONCLUSIONS

These data demonstrate a dichotomous impact of storage on immunization to distinct RBC antigens, offering a possible explanation for inconsistent clinical experience and the need for additional studies on the relationship between RBC storage and alloimmunization.

Genotypic and Phenotypic Composition of Sickle Cell Disease in the Arab Population - A Systematic Review

Sickle cell disease (SCD) is a genetic disease influenced by ethnicity and regional differences in its clinical course. Recent advances in the management of SCD with newer therapies are being introduced to the Western population. However, many of these treatments are yet to be used in the Arabic SCD population. Understanding the genetic variations of SCD regionally is essential to anticipate the utilization of new treatments. This systematic review's main objective is to pool the available data on the genetic composition of SCD in the Arabic population. Data for 44,034 patients was extracted from 184 studies (11 case reports, 8 case series, 56 retrospectives, 107 prospective observational studies, and 2 clinical trials) using PubMed, Scopus, and Google Scholar. Male (49%) and female (51%) patients were equally reported wherever gender was available (N=13105). Various SCD genotypes were reported in a total of 14,257 patients, including Hb SS (77%) Hb Sβ0 (9.9%), and Hb Sβ+ (7.2%), while the rest of the genotypes, including HbSC, HbSD, HbSE, HbSO Arab, Hb S/α-Thal, Hb Sβ0 + α-Thal, and HBS Oman were individually reported in <4% of the cases. Major SCD complications in the Arab population included pain crises (48.25%) followed by neurological complications (33.46%), hepatobiliary complications (25.53%), musculoskeletal complications (24.73%), and hemolytic anemia (23.57%). The treatments reported for SCD included hydroxyurea (20%), blood transfusion (14.32%), and Deferasirox (3.03%). We did not find the use of stem cell transplantation or newer treatments such as L-Glutamine, Voxelotor, Crizanlizumab, or gene therapy reported in any of the studies included in our review. This review highlights the genetic makeup of SCD in Arab countries and its common phenotypic manifestations and will help direct further research on SCD in this region, especially concerning genetic therapy.

Systematic Review Registration

The protocol has been registered in the International Prospective Register of Systematic Reviews(PROSPERO):CRD42020218,666. https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=218666.

Plasma Non-transferrin-Bound Iron Could Enter into Mice Duodenum and Negatively Affect Duodenal Defense Response to Virus and Immune Responses

Plasma non-transferrin-bound iron (NTBI) exists when the plasma iron content exceeds the carrying capacity of transferrin and can be quickly cleared by the liver, pancreas, and other organs. However, whether it could enter the small intestine and its effects still remain unclear. Herein, these issues were explored. Mice were intravenously administrated of ferric citrate (treatment) or citrate acid (control) 10 min after the saturation of the transferrin. Two hours later, hepatic, duodenal, and jejunal iron content and distribution were measured and duodenal transcriptome sequencing was performed. Significant increase of duodenal and hepatic iron content was detected, indicating that plasma NTBI could be absorbed by the duodenum as well as the liver. A total of 103 differentially expressed genes were identified in the duodenum of mice in the treatment group compared to the control group. Gene Ontology (GO) functional analysis of these genes showed that they were mainly involved in defense response to virus and immune response. The results of Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) analysis revealed that there were major changes in the hematopoietic cell lineage and some virus infection pathways between the two groups. Determination of 7 cytokines in the duodenum were further conducted, which demonstrated that the anti-inflammatory factors interferon (IL)-4 and IL-10 in the duodenum were significantly decreased after NTBI uptake. Our findings revealed that NTBI in plasma can enter the duodenum, which would change the duodenal hematopoietic cell lineage and have a negative impact on defense response to the virus and immune responses.

A conservative approach in finding compatible blood for a patient with sickle cell disease having multiple alloantibodies

BACKGROUND

Sickle cell disease (SCD) patients may develop multiple alloantibodies that pose problem in finding compatible blood for transfusion and require crossmatching with large number of blood.

AIM

The aim of the present study was to find compatible blood with reduced cost by adopting a conservative approach.

MATERIALS AND METHODS

A step-by-step approach using tube technique, antibodies in original serum, and the saved test supernatant (TS) in search of compatible blood for transfusion purposes.

RESULTS

32 years SCD patient grouped A with multiple antibodies required transfusion. A total of 641 red blood cell (RBC) units of groups A and O were crossmatched using serum and the TS by tube method. Of 138 units tested using the serum at 4°C, 124 units showed direct agglutination in the saline phase and the remaining 14 units were processed through low ionic strength solution (LISS)-IAT, of which 2 units were compatible even by the gel-IgG-card method. The TS, saved from the tests on serum, was used in an identical manner as that of the serum to screen additional 503 units by saline tube method at 4°C units showed direct agglutination of the RBCs of 428 units, hence were removed from inventory for this patient. The remaining 75 units were tested by the LISS-IAT-tube method at 37°C, of which 8 units were found compatible but only 2 units were clear compatible by the gel-IgG-card method. As such, 4 units compatible by the sensitive gel-IgG-card method were issued for transfusion purposes.

CONCLUSION

The new approach on using the saved TS consumed less of the patient's blood specimen, and the use of the tube method in screening and eliminating a large chunk of incompatible blood units has proved economical if compared with the use of the only gel-IgG-cards device in the entire maneuvering.

Managing the Cerebrovascular Complications of Sickle Cell Disease: Current Perspectives

The importance of protecting brain function for people with sickle cell disease (SCD) cannot be overstated. SCD is associated with multiple cerebrovascular complications that threaten neurocognitive function and life. Without screening and preventive management, 11% of children at 24% of adults with SCD have ischemic or hemorrhagic strokes. Stroke screening in children with SCD is well-established using transcranial Doppler ultrasound (TCD). TCD velocities above 200 cm/s significantly increase the risk of stroke, which can be prevented using chronic red blood cell (RBC) transfusion. RBC transfusion is also the cornerstone of acute stroke management and secondary stroke prevention. Chronic transfusion requires long-term management of complications like iron overload. Hydroxyurea can replace chronic transfusions for primary stroke prevention in a select group of patients or in populations where chronic transfusions are not feasible. Silent cerebral infarction (SCI) is even more common than stroke, affecting 39% of children and more than 50% of adults with SCD; management of SCI is individualized and includes careful neurocognitive evaluation. Hematopoietic stem cell transplant prevents cerebrovascular complications, despite the short- and long-term risks. Newer disease-modifying agents like voxelotor and crizanlizumab, as well as gene therapy, may treat cerebrovascular complications, but these approaches are investigational.

Hemoglobin and End-Organ Damage in Individuals with Sickle Cell Disease

Background

Sickle cell disease (SCD) is an inherited, chronic, multifaceted blood disorder. Patients with SCD develop anemia, which has been associated with end-organ damage (EOD).

Objectives

This retrospective, observational, repeated-measures study systematically characterizes the relationship between hemoglobin (Hb) level and EOD in adolescent and adult patients with SCD.

Methods

The study population comprised patients with SCD aged ≥12 years with available Hb data from a US provider-centric health care database. For each patient, each Hb value over time was included as a separate observation. Study outcomes-the onset of any new EOD, including chronic kidney disease, pulmonary hypertension, stroke, and leg ulcer-were ascertained during the 1-year period after each Hb assessment. The association between Hb levels and risk of new EOD was estimated using multivariable generalized estimating equations.

Results

A total of 16,043 unique patients with SCD contributed 44,913 observations. Adjusted odds of any EOD during the 1-year follow-up were significantly lower with higher Hb level. Risk reductions with higher Hb levels for chronic kidney disease, pulmonary hypertension, and leg ulcer were comparable. The risk of new EOD was significantly lower among adolescent and adult patients with higher Hb levels.

Conclusions

In patients with SCD, higher Hb levels are associated with a reduced risk of developing EOD. Therapeutic strategies that result in higher Hb levels may offer clinical and economic value for patients with SCD. (Curr Ther Res Clin Exp. 2023; 84:XXX-XXX).

Blood banking considerations in pediatric trauma

ABSTRACT

Transfusion of blood products to a hemorrhaging pediatric trauma patient requires seamless partnership and communication between trauma, emergency department, critical care, and transfusion team members. To avoid confusion and delays, understanding of blood banking principles and mutually agreed upon procedures and policies must be regularly updated as knowledge evolves. Because pediatric patients require specialized considerations distinct from those in adults, this brief review covers transfusion principles, policies, and procedures specific to the resuscitation of pediatric trauma patients.

Stroke in sickle cell disease and the promise of recent disease modifying agents

Sickle cell disease (SCD) is an inherited hemoglobinopathy affecting approximately 100,000 individuals in the United States. Cerebrovascular disease is among the most common and debilitating complications of SCA, with 53% experiencing silent cerebral infarct by age 30 and 3.8% experiencing overt stroke by age 40 years. This review highlights the burden of cerebrovascular disease in SCD, including both stroke and silent cerebral infarct (SCI). We then discuss the pathophysiology of stroke and cerebral fat embolism in the absence of a patent foramen ovale. This review also reveals that options for primary and secondary stroke prevention in SCD are still limited to hydroxyurea and blood transfusion, and that the role of aspirin and anticoagulation in SCD stroke has not been adequately studied. Limited data suggest that the novel disease-modifying agents for SCD management may improve renal dysfunction, leg ulcers, and lower the abnormally high TCD flow velocity. Further research is urgently needed to investigate their role in stroke prevention in SCD, as these novel agents target the main stroke contributors in SCD - hemolysis and vaso-occlusion. This literature review also explores the role of healthcare disparities in slowing progress in SCD management and research in the United States, highlighting the need for more investment in patient and clinician education, SCD management, and research.

Red blood cell alloimmunisation in sickle cell disease patients in the Democratic Republic of the Congo

OBJECTIVES

To determine the prevalence of red blood cell (RBC) alloimmunisation and alloantibody specificity in sickle cell disease (SCD) patients in Kisangani, Democratic Republic of Congo (DRC) in comparison with those followed at the Centre Hospitalier Régional (CHR) de la Citadelle of Liège (Belgium).

BACKGROUND

Data regarding RBC alloimmunisation (immune response of the organism to foreign erythrocyte antigens, antigens that lack on its own RBC) in SCD patients are scarce in sub-Saharan Africa.

METHODS

We conducted a multi-site-based cross-sectional study among 125 SCD patients at Kisangani and 136 at the CHR de la Citadelle of Liège. The diagnosis of SCD was confirmed by high-performance liquid chromatography. Alloantibodies were screened using the agglutination technique on gel cards and their specificity determined using 11 and/or 16 cell panels. Statistical analyses were carried out using SPSS.

RESULTS

The prevalence of RBC alloimmunisation was 9.6% among SCD patients in Kisangani versus 22.8% in those of Liège. At Kisangani as well as at Liège, the median age of alloimmunised patients was higher than that of non-alloimmunised patients, 15.5 years (IQR:4.8-19.8) and 24 years (IQR:14-31) versus 10 years (IQR: 6.5-17) and 17 years (IQR:12-24), respectively. The median number of blood units was higher in both Kisangani and Liège immunised patients compared to non-immunised patients, 8 (IQR:5-11) versus 5 (IQR:3-13) and 41(IQR:6-93) versus 6.5(3-37) respectively. At Kisangani (N = 14), the most frequent antibodies were anti-D (28.6%) and anti-C versus anti-E (13.6%), anti-S (13.6%) and anti-Lea (11.4%) at Liège (N = 44).

CONCLUSIONS

These findings stated that alloimmunisation is a common complication in SCD patients in the DRC. In the resource-limited setting of this country, blood transfusion with minimal ABO, D, C and E antigen matching in addition to the use of compatibility test could significantly reduce the incidence of this complication.

Low-cost molecular methodology for blood group antigens identification and genotyping contribution to transfusion efficacy in multiple transfused patients

BACKGROUND

Blood transfusions usually result in the production of alloantibodies, complicating subsequent transfusions. Many blood group systems, in addition to ABO and Rh, can lead to the production of irregular antibodies in multiple transfused patients.

OBJECTIVES

The aim of this work was to standardize a molecular biology methodology for identified some alleles of KEL, FY, JK and DI blood group system; the transfusion efficacy of chronically transfused patients with phenotype-matched blood was also evaluated.

METHODS

A PCR-SSP was developed and validated using Sanger sequencing. The genotype and frequencies of 141 multiple transfused patients treated at blood banks of Maringá were compared with the blood donor's population to assess the availability of compatible blood bags. The clinical history of 29 patients on a phenotype-compatible transfusion regimen was followed to assess pre- and post-genotyping alloimmunization.

RESULTS

The PCR-SSP was effective in identifying the genotypes under study. Significant differences were observed in genotype and allele frequencies for FY and JK. Compatible bags were identified for all patients. Most patients (93.1%) did not develop new alloantibodies after erythrocyte genotyping.

CONCLUSION

Erythrocyte genotyping proved to be important both in the search for positive blood bags for rare alleles and in the prevention of alloimmunization.

Perioperative Pediatric Erythrocyte Transfusions: Incorporating Hemoglobin Thresholds and Physiologic Parameters in Decision-making

This article presents current literature and scientific evidence on hemoglobin thresholds and physiologic parameters to guide decisions regarding perioperative erythrocyte transfusions in pediatric patients based on the most up-to-date studies and expert consensus recommendations.

The use of pluripotent stem cells to generate diagnostic tools for transfusion medicine

Red blood cell (RBC) transfusion is one of the most common medical treatments, with more than 10 million units transfused per year in the United States alone. Alloimmunization to foreign Rh proteins (RhD and RhCE) on donor RBCs remains a challenge for transfusion effectiveness and safety. Alloantibody production disproportionately affects patients with sickle cell disease who frequently receive blood transfusions and exhibit high genetic diversity in the Rh blood group system. With hundreds of RH variants now known, precise identification of Rh antibody targets is hampered by the lack of appropriate reagent RBCs with uncommon Rh antigen phenotypes. Using a combination of human-induced pluripotent stem cell (iPSC) reprogramming and gene editing, we designed a renewable source of cells with unique Rh profiles to facilitate the identification of complex Rh antibodies. We engineered a very rare Rh null iPSC line lacking both RHD and RHCE. By targeting the AAVS1 safe harbor locus in this Rh null background, any combination of RHD or RHCE complementary DNAs could be reintroduced to generate RBCs that express specific Rh antigens such as RhD alone (designated D--), Goa+, or DAK+. The RBCs derived from these iPSCs (iRBCs) are compatible with standard laboratory assays used worldwide and can determine the precise specificity of Rh antibodies in patient plasma. Rh-engineered iRBCs can provide a readily accessible diagnostic tool and guide future efforts to produce an alternative source of rare RBCs for alloimmunized patients.

Adverse events of red blood cell transfusions in patients with sickle cell disease

Blood transfusion is a common medical intervention for patients with sickle cell disease (SCD) and disease related complications. While patients with SCD are at risk for all transfusion related adverse events defined by the National Healthcare Safety Network (NHSN) Biovigilance Component Hemovigilance Module Surveillance Protocol, they are uniquely susceptible to certain adverse events. This review discusses risk factors, mitigation strategies, and management recommendations for alloimmunization, hemolytic transfusion reactions, hyperviscosity and transfusion-associated iron overload in the context of SCD.

An overview of red blood cell and platelet alloimmunisation in transfusion

Post-transfusion alloimmunisation is the main complication of all those observed after one or more transfusion episodes. Alloimmunisation is observed after the transfusion of red blood cell concentrates but also of platelet concentrates. Besides alloimmunisation due to antigens carried almost exclusively by red blood cells such as those of the Rhesus-Kell system, alloimmunisation often raises against HLA antigens; the main responsibility for that, apart from platelet transfusions, lies with residual leukocytes in the products transfused, hence the central importance of effective leukoreduction right from the blood product preparation stage. Alloimmunization is not restricted to transfusion, but it is also observed during pregnancies, carrying out microtransfusions of blood from the fetus immunizing the mother through the placenta (in a retrograde way). Preexisting maternal-fetal immunization can complicate a transfusion program and intensify the creation of alloantibodies in several blood and tissue group systems. The occurrence of autoantibodies, created by several pathogenic reasons, can also interfere with the propensity of certain recipients of blood components to produce alloantibodies. The genetic condition of individuals is in fact strongly linked to the ability or not to recognize antigenic variants foreign to their own biological program and mount an alloimmune response. Some hemoglobin diseases, in carriers of which transfusions can be iterative and lifelong, are complicated by frequent alloimmunizations and amplification of the complications of these alloimmunizations, imposing even stricter transfusion rules. This review details the mechanisms favoring the occurrence of alloimmunization and the immunological principles for the production of molecular and cellular tools for alloimmunization. It concludes with the main preventive measures available to limit the occurrence of these frequent complications of varying severity but sometimes severe.

Transfusional Approach in Multi-Ethnic Sickle Cell Patients: Real-World Practice Data From a Multicenter Survey in Italy

Sickle cell disease (SCD) is a worldwide distributed hereditary red cell disorder characterized by recurrent acute vaso-occlusive crises (VOCs and anemia). Gold standard treatments are hydroxycarbamide (HC) and/or different red blood cell (RBC) transfusion regimens to limit disease progression. Here, we report a retrospective study on 1,579 SCD patients (median age 23 years; 802 males/777 females), referring to 34 comprehensive Italian centers for hemoglobinopathies. Although we observed a similar proportion of Caucasian (47.9%) and African (48.7%) patients, Italian SCD patients clustered into two distinct overall groups: children of African descent and adults of Caucasian descent. We found a subset of SCD patients requiring more intensive therapy with a combination of HC plus chronic transfusion regimen, due to partial failure of HC treatment alone in preventing or reducing sickle cell-related acute manifestations. Notably, we observed a higher use of acute transfusion approaches for SCD patients of African descent when compared to Caucasian subjects. This might be related to (i) age of starting HC treatment; (ii) patients' low social status; (iii) patients' limited access to family practitioners; or (iv) discrimination. In our cohort, alloimmunization was documented in 135 patients (8.5%) and was more common in Caucasians (10.3%) than in Africans (6.6%). Alloimmunization was similar in male and female and more frequent in adults than in children. Our study reinforces the importance of donor-recipient exact matching for ABO, Rhesus, and Kell antigen systems for RBC compatibility as a winning strategy to avoid or limit alloimmunization events that negatively impact the clinical management of SCD-related severe complications.

A Systematic Review on the Management of Transfusion-Related Acute Lung Injury in Transfusion-Dependent Sickle Cell Disease

The onset of respiratory distress and acute lung injury (ALI) following a blood transfusion is known as transfusion-related acute lung injury (TRALI), although its pathophysiology remains unknown. Even though sickle cell disease (SCD) has been studied for more than a century, few therapeutic and management strategies adequately address the emergence of TRALI. TRALI, an immune-mediated transfusion response that can result in life-threatening consequences, is diagnosed based on clinical signs and symptoms. Early detection and treatment increase the chances of survival and, in most cases, result in a complete recovery. Our objective is to provide a firm grasp of the present status of SCD-related TRALI care and therapy.

After exploring multiple databases, this study offers evidence-based guidelines to aid clinicians and other healthcare professionals make decisions concerning transfusion assistance for SCD and the management of transfusion-related complications. Other risk factors for acute lung injury including sepsis aspiration should be ruled out throughout the diagnostic process. Several recent studies have shown that immunotherapy or immunological targets can effectively prevent these complications. Red cell transfusions, red cell antigen matching optimization, and iron chelation can also help reduce negative consequences. It is to be noted that poor clinical outcomes can be avoided by early detection and treatment of hemolytic transfusion reactions. Finally, preventing the onset of TRALI may be the most effective therapeutic strategy for SCD patients who rely on blood transfusions for survival.

Blood transfusion and iron overload in patients with Sickle Cell Disease (SCD): Personal experience and a short update of diabetes mellitus occurrence

The conventional treatment of β-thalassemia (β-TM) patients is based on the correction of anemia through regular blood transfusions and iron chelation therapy. However, allogeneic hematopoietic stem cell transplantation (HSCT) remains the only currently available technique that has curative potential. Variable frequency and severity of long-term growth and endocrine changes after conventional treatment as well as after HSCT have been reported by different centers. The goal of this mini-review is to summarize and update knowledge about long-term growth and endocrine changes after HSCT in patients with β-TM in comparison to those occurring in β-TM patients on conventional treatment. Regular surveillance, early diagnosis, treatment, and follow-up in a multi-disciplinary specialized setting are suggested to optimize the patient's quality of life (www.actabiomedica.it).

Iron Overload in Patients With Heavily Transfused Sickle Cell Disease-Correlation of Serum Ferritin With Cardiac T2* MRI (CMRTools), Liver T2* MRI, and R2-MRI (Ferriscan®)

The treatment of sickle cell disease (SCD) is mainly supportive, except for a minority, who receive bone marrow transplantation (BMT). Serum ferritin (SF) is routinely available but is notoriously unreliable as a tool for iron-overload assessment since it is an acute-phase reactant. Although blood transfusion is one of the most effective ways to deal with specific acute and chronic complications of SCD, this strategy is often associated with alloimmunization, iron overload, and hemolytic reactions. This study, thus, aims to evaluate iron overload in patients with SCD on chronic blood transfusions and specifically, correlate SF with the current standard of care of iron-overload assessment using MRI-based imaging techniques. Amongst a historic cohort of 58 chronically transfused patients with SCD, we were able to evaluate 44 patients who are currently alive and had multiple follow-up testing. Their mean age (±SD) was 35 (9) years and comprised of 68.2% of women. The studied iron-overload parameters included cardiac T2^* MRI, liver iron concentration (LIC) by Liver T2^* MRI, and serial SF levels. Additionally, in a smaller cohort, we also studied LIC by FerriScan^© R2-MRI. Chronic blood transfusions were necessary for severe vaso-occlusive crisis (VOC) (38.6%), severe symptomatic anemia (38.6%), past history of stroke (15.9%), and recurrent acute chest syndrome (6.9%). About 14 (24%) patients among the original cohort died following SCD-related complications. Among the patients currently receiving chelation, 26 (96%) are on Deferasirox (DFX) [Jadenu® (24) or Exjade® (2)], with good compliance and tolerance. However, one patient is still receiving IV deferoxamine (DFO), in view of the significantly high systemic iron burden. In this evaluable cohort of 44 patients, the mean SF (±SD) reduced marginally from 4,311 to 4,230 ng/ml, mean Liver T2^* MRI dropped from 12 to 10.3 mg/gm dry weight, while the mean cardiac T2^*MRI improved from 36.8 to 39.5 ms. There was a mild to moderate correlation between the baseline and final values of SF ng/ml, r = 0.33, p = 0.01; Cardiac T2^* MRI ms, r = 0.3, p = 0.02 and Liver T2^* MRI mg/kg dry weight, r = 0.6, p < 0.001. Overall, there was a positive correlation between SF and Liver T2^* MRI (Pearson's r = 0.78, p < 0.001). Cardiac T2^*MRI increased with the decreasing SF concentration, showing a negative correlation which was statistically significant (Pearson's r = -0.6, p < 0.001). Furthermore, there was an excellent correlation between SF ng/ml and LIC by FerriScan^© R2-MRI mg/g or mmol/kg (Spearmen's rho = -0.723, p < 0.008) in a small subset of patients (n = 14) who underwent the procedure. In conclusion, our study demonstrated a good correlation between serial SF and LIC by either Liver MRI T2^* or by FerriScan^© R2-MRI, even though SF is an acute-phase reactant. It also confirms the cardiac sparing effect in patients with SCD, even with the significant transfusion-related iron burden. About 14 (24%) patients of the original cohort died over the past 15 years, indicative of a negative impact of iron overload on disease morbidity and mortality.