Donor Red Blood Cells Research Articles

C1q Binding Ability for Prior Risk Assessment of Acute Antibody-Mediated Rejection in ABO-Incompatible Kidney Transplantation.

In ABO blood group incompatible kidney transplantation (ABO-I), potential issues on acute antibody-mediated rejection (ABMR) remain to be solved. This study aimed to assess the risk factors of acute ABMR using recipient- or donor-derived specimens. Quantitative analysis of A/B antigen expression was conducted in 104 donor kidney tissues (Kt), platelets (Plt), and red blood cells (RBC) by immunohistochemical staining or flow cytometry (FCM). ABO-I pre-transplant recipient serum samples (ABMR = 12, non-ABMR = 27) were extracted by propensity score matching. Anti-A antibody titers of IgM, IgG and IgG subclasses, and C1q binding ability (%) on antibody were measured using RBC-FCM. No association was observed between ABMR and A/B antigen expression levels in donor's Plt, RBC, or Kt. In recipient's sample, C1q-IgG binding ability was significantly higher in the ABMR group than in the non-ABMR group (C1q-IgG: 9.04% vs. 5.93% p = 0.049). Neither the A/B antigen expression level in donors (grafts) nor anti-blood group IgG/IgM antibodies in recipient sera before desensitization seemed to influence ABMR incidence in ABO-I. In contrast, C1q-IgG binding ability could be a potential predictor for ABMR in ABO-I.

Identification of feline erythrocyte antigen 6 and lack of alloimmunization to feline erythrocyte antigen 4 in cats.

New feline erythrocyte antigens (FEAs) have been described based on the presence of naturally occurring alloantibodies (NOAb), but their immunogenicity and clinical relevance are poorly understood. Describe the immunogenicity of FEA 4 after sensitizing FEA 4-negative cats lacking NOAb and characterize anti-FEA 4 alloantibodies produced, including their rate of appearance, agglutination titer, and immunoglobulin class. Nineteen healthy type A cats were blood typed for FEAs 1 to 5 to identify suitable donor-recipient pairs for FEA 4 sensitization. Four FEA 4-negative cats were transfused with FEA 4-positive red blood cells. Using a gel column technique, posttransfusion samples were screened daily for a week, weekly for a month, and monthly thereafter for anti-FEA 4 alloantibodies. Alloantibodies were not detected in the first 3 recipients despite repeated transfusions (1 and 3 additional transfusions for 2 and 1 recipients, respectively). In the 4th recipient, alloantibodies against its donor red blood cells were detected 21 days postsensitization. However, they were not directed against FEA 4, but rather against a novel FEA not yet described. The alloantibodies, named anti-FEA 6, remained detectable for >4 months after sensitization and were determined to be mostly immunoglobulin M based on sulfhydryl treatment. Feline erythrocyte antigen 4 does not appear to be immunogenic because repeated sensitization of 4 cats failed to produce detectable anti-FEA 4 alloantibodies. A new immunogenic antigen, named FEA 6, has been discovered, but additional studies are needed to document its clinical importance.

How do we manage hyperhemolysis syndrome.

Hyperhemolysis syndrome (HHS) is a catastrophic anemia characterized by destruction of both donor and patient red blood cells (RBC). HHS occurs after transfusion and can cause significant morbidity and mortality. Given the difficulty in diagnosing and managing this process, we provide a detailed overview of our treatment protocol. Members of the Transfusion Medicine and Hematology faculty at our institution collaborated in an iterative process to produce a consensus approach to patients with HHS. We present diagnostic criteria for HHS: recent transfusion within past 7 days (up to 21 days), rapid hemoglobin decline to below the pretransfusion level (usually hemoglobin drop >25% from pretransfusion), a significant decrease in HbA% (in patients with sickle cell disease or beta thalassemia), low or decreasing reticulocyte count in a patient with worsening anemia, and laboratory evidence of hemolysis. We also describe an in-depth approach to management focusing on optimizing hematopoiesis while dampening the immune response. We provide a comprehensive approach to the diagnosis and management of HHS based on contemporary literature and clinical experience designed to optimize outcomes for patients.

Seven-years post allogeneic hematopoietic stem cell transplantation pure red cell aplastic anemia cured with daratumumab: A case report and review of literature

BACKGROUND Allogeneic hematopoietic stem cell transplantation (Allo-HSCT) is currently the only viable method of curing patients with acute myeloid leukaemia. In 30% to 50% of patients, donors and recipients have some level of ABO blood group incompatibility. ABO blood group incompatibility can cause antibodies against the donor's red blood cells to persist in the recipient's body, resulting in a delay of several months in the recovery of red blood cells. A number of different treatments have been reported for post-transplant pure red cell aplastic anaemia (PRCA), such as plasmapheresis, donor lymphocyte infusions, anti-thymocyte globulin, rituximab and steroids. CASE SUMMARY A 41-year-old female diagnosed with acute myeloid leukaemia underwent peripheral blood allogeneic haematopoietic stem cell transplantation in November 2013 from an HLA matched unrelated donor. The donor was AB-positive and the recipient was O-positive. The patient was diagnosed with PRCA three months after receiving the donor stem cell transplant. After failing multiple lines of therapy, the patient applied for daratumumab. After receiving three doses of daratumumab, the patient developed a reticulocyte response and no longer required blood transfusions. CONCLUSION The use of daratumumab anti-CD38 for the remove of plasma cells is safe and effective and may be tried for refractory patients with PRCA after undergoing allo-HSCT for ABO incompatibility.

“When less is more and more is less” red cell alloimmunization in multitransfused patients attending a medical institution with a newly developed blood center in North India: A multifactorial study

Abstract: INTRODUCTION: Multiple blood transfusions with one or more nonself, genetically mismatched donor red blood cells (RBCs) may result in the production of alloantibodies, complicating future transfusions and increasing patient morbidity. This could be averted if adequate prophylactic measures are implemented in the vulnerable group. Due to the paucity of data in our region, we planned this study to identify the alloimmunization pattern in relation to clinical and demographic patient factors. MATERIALS AND METHODS: A prospective observational study was carried out in a newly developed Medical Institution of National importance in Northern India, for 1 year. The red cell antibody screening and identification were done for 770 patients receiving two or more transfusions. The patient and transfusion-related factors were statistically compared between alloimmunized and nonalloimmunized cases. RESULTS: The overall seroprevalence of RBC alloimmunization among the multi-transfused patients was 4.02% (31/770). Thirty-six alloantibodies were identified in the 31 alloimmunized patients, which comprised 13 different alloantibody specificities. Most of them belonged to the Rh system (38.8%), followed by MNS (25%) and Lewis (27.7%) blood group systems. On Multivariate logistic regression analysis, the highest risk was found to be associated with recipients having more than three transfusions with an odds ratio of 8.4. CONCLUSIONS: The highest alloimmunization risk was found in multi-transfused patients receiving more than three transfusions and with female gender. Rh blood group system was found to be predominating the alloantibody specificity pattern. This highlights the need for the provision of extended Rh (DCcEe) matched packed red cells for susceptible patients.

The annual prevalence of syphilis among blood donors of regional blood centers of Sindh: A study conducted by the Sindh blood transfusion authority to evaluate the infectious rate of syphilis among blood donors.

Objective: To detect any possible illnesses, such as syphilis, and stop them from spreading through transfusion, screening blood donors is crucial. Study Design: Cross-sectional Retrospective Research study. Setting: Four RBCs and the sixteen associated hospital-based blood banks (HBBBs) that are spread over Sindh's various areas. Period: January 2022 to December 2022. Methods: Employing non-probability convenience sampling was carried out. We collected data from Sindh province's Regional Blood Centers (RBCs) and Hospital Based Blood Banks (HBBBs), dispersed throughout the province. Sindh Blood Transfusion Authority (SBTA)'s ethical committee approved the study. To screen selected blood donors for Syphilis, the Chemiluminescence Immunoassay Analyzer (CLIA) was used. Data from the study were summarized using simple percentages after they were statistically examined. Results: With 171,725 male donors and 1,460 female donors, men comprised the bulk of the 173,185 blood donors. Syphilis turned up in 2.5% of the male donors, resulting in an additional 4,311 cases. On the other hand, just 18 (1.2%) of the female donors had a positive syphilis test. The gender distribution of cases with positive Syphilis indicates a notable difference in its frequency between people of both sexes. The age group of 25 to 40 years old accounted for the largest proportion of syphilis cases among blood donors. Conclusion: One of Sindh's biggest public health concerns is the high incidence of syphilis among blood donors. Additionally, the results show that the incidence of syphilis varies by gender. Furthermore, there are considerable age range differences in the distribution of syphilis cases. These results highlight the need for increased screening and preventive programmes, especially in areas with higher incidence rates. Given the high frequency of syphilis among Sindhi red blood cell donors, this could point to a greater number of cases in the overall community.

A genome-wide association study of alloimmunization in the TOPMed OMG-SCD cohort identifies a locus on chromosome 12.

Red cell alloimmunization after exposure to donor red cells is a very common complication of transfusion for patients with sickle cell disease (SCD), resulting frequently in accelerated donor red blood cell destruction. Patients show substantial differences in their predisposition to alloimmunization, and genetic variability is one proposed component. Although several genetic association studies have been conducted for alloimmunization, the results have been inconsistent, and the genetic determinants of alloimmunization remain largely unknown. We performed a genome-wide association study (GWAS) in 236 African American (AA) SCD patients from the Outcome Modifying Genes in Sickle Cell Disease (OMG-SCD) cohort, which is part of Trans-Omics for Precision Medicine (TOPMed), with whole-genome sequencing data available. We also performed sensitivity analyses adjusting for different sets of covariates and applied different sample grouping strategies based on the number of alloantibodies patients developed. We identified one genome-wide significant locus on chr12 (p = 3.1e-9) with no evidence of genomic inflation (lambda = 1.003). Further leveraging QTL evidence from GTEx whole blood and/or Jackson Heart Study PBMC RNA-Seq data, we identified a number of potential genes, such as ARHGAP9, STAT6, and ATP23, that may be driving the association signal. We also discovered some suggestive loci using different analysis strategies. We call for the community to collect additional alloantibody information within SCD cohorts to further the understanding of the genetic basis of alloimmunization in order to improve transfusion outcomes.

Donor vs. Donor or Recipient vs. Recipient? A Singular Case of Post Hematopoietic Stem Cell Transplantation Autoimmune Hemolytic Anemia in a Pediatric Patient

Hematopoietic Stem Cell Transplantation (HSCT) is a curative treatment for certain blood disorders, but can lead to complications such as Autoimmune Cytopenia (AIC), particularly Autoimmune Hemolytic Anemia (AIHA). AIHA after HSCT often involves donor-derived antibodies attacking donor red blood cells, but this case report describes a unique case in a 7-year-old male with beta-thalassemia major. Following HSCT, he developed AIHA nine months after transplantation from an unrelated donor. Despite initially successful engraftment, chimerism analysis revealed a decline in donor cells coincident with the onset of AIHA. The patient had severe hemolysis, a positive Direct Coombs Test (DAT) for IgG and C3d, and several antibodies including anti-e, anti- C, and anti-D. Treatment with cyclosporine and prednisone initially stabilized his condition, but discontinuation resulted in relapse, worsening chimerism, and increased antibody titers. Analysis confirmed the predominance of recipient immune cells, suggesting that AIHA was driven by the recipient's immune response against his own red blood cells. This case emphasizes the complexity of immune reconstitution after HSCT and highlights a recipient-versus-recipient mechanism in post-transplant AIHA.

Red Blood Cell Membrane-Coated Nanoparticles Enable Incompatible Blood Transfusions.

Blood transfusions save lives and improve health every day. Despite the matching of blood types being stricter than it ever has been, emergency transfusions among incompatible blood types are still inevitable in the clinic when there is a lack of acceptable blood types for recipients. Here to overcome this, a counter measure nanoplatform consisting of a polymeric core coated by a red blood cell (RBC) membrane is developed. With A-type or B-type RBC membrane camouflaging, the nanoplatform is capable of specifically capturing anti-A or anti-B IgM antibodies within B-type or A-type whole blood, thereby decreasing the corresponding IgM antibody levels and then allowing the incompatible blood transfusions. In addition to IgM, the anti-RBC IgG antibody in a passive immunization murine model can likewise be neutralized by this nanoplatform, leading to prolonged circulation time of incompatible donor RBCs. Noteworthily, nanoplatform made by expired RBCs (>42 days stored hypothermically) and then subjected to lyophilization does not impair their effect on antibody neutralization. Most importantly, antibody-captured RBC-NP do not exacerbate the risk of inflammation, complement activation, and coagulopathy in an acute hemorrhagic shock murine model. Overall, this biomimetic nanoplatform can safely neutralize the antibody to enable incompatible blood transfusion.

Highly Defined Induced Pluripotent Stem Cell Lines Mimic Donor Red Blood Cell Antigen Profiles for Therapeutic and Diagnostic Use.

Our group generated two induced pluripotent stem cell (iPSC) lines for in vitro red blood cell (RBC) production from blood donors with extensively known erythrocyte antigen profiles. One line was intended to give rise to RBCs for transfusions in patients with sickle cell disease (SCD), while the other was developed to create RBC panel reagents. Two blood donors were selected based on their RBC phenotypes, further complemented by high-throughput DNA array analysis to obtain a more comprehensive erythrocyte antigen profile. Enriched erythroblast populations from the donors' peripheral blood mononuclear cells were reprogrammed into iPSCs using nonintegrative plasmid vectors. The iPSC lines were characterized and subsequently subjected to hematopoietic differentiation. iPSC PB02 and iPSC PB12 demonstrated in vitro and invivo iPSC features and retained the genotype of each blood donor's RBC antigen profile. Colony-forming cell assays confirmed that iPSC PB02 and iPSC PB12 generated hematopoietic progenitors. These two iPSC lines were generated with defined erythrocyte antigen profiles, self-renewal capacity, and hematopoietic differentiation potential. With improvements in hematopoietic differentiation, these cells could potentially be more efficiently differentiated into RBCs in the future. They could serve as a complementary approach for obtaining donor-independent RBCs and addressing specific demands for blood transfusions.

A patient with anti-f in India identified by extensive immunohematologic workup.

Anti-f is produced by exposure to the compound antigen ce (f) on red blood cells (RBCs), expressed when both c and e are present on the same protein (cis position). Although anti-f was discovered in 1953, there are few cases reported worldwide because the presence of anti-f is often masked by anti-c or anti-e and is not generally found as a single antibody. In the present case, anti-f was identified by using three-cell screening and 11-cell identification panels. The identification of anti-f was further supported by additional testing, including (1) Rh antigen typing; (2) antibody identification panels (enzyme-treated panel [ficin] and an in-house-constructed Rh panel); (3) look-back and phenotyping of donor RBC units, which were responsible for alloimmunization; and (4) molecular testing of the patient's RBCs.

Modification of deglycerolization procedure improves processing and post-thaw quality of cryopreserved sickle trait red cell concentrates

Red blood cell (RBC) transfusion is a critical therapy for those with sickle cell disease (SCD). Alloimmunization is frequent for those with SCD and may limit the availability of matched RBC. Cryopreserved RBCs, from family members or donors with a similar RBC antigen profile could provide a viable alternative to avoid further alloimmunization and prevent hemolytic transfusion-related events. However, cryopreserved SCD and Sickle Cell trait (S-trait) donor RBC units suffer from reduced recovery following deglycerolization. This study proposes and tests a modified deglycerolization protocol using an automated cell processor to mitigate RBC loss. Six red cell concentrates (RCC) from donors with S-trait and six control RCCs were glycerolized, frozen (<−65 °C) and deglycerolized on the ACP 215 using modified parameters (decreased hypertonic solution flow rate (100 mL/min) and hypertonic equilibration delay (120 s), and increased NaCl dilution volumes (500 mL). Quality testing included: hematocrit (HCT), hemolysis, indices, extracellular potassium, morphology, osmotic fragility, osmotic gradient ektacytometry, hemoglobin (HGB), and recovery. Canadian standards (CS) indicate that acceptable deglycerolized units for transfusion require a HCT ≤0.80 L/L, HGB ≥35 g/unit, and hemolysis <0.8 % in 90 % of units tested. No significant differences in HGB or RBC recovery were observed between study groups. Significant differences between study groups were identified in osmotic fragility and osmotic gradient ektacytometry parameters. Of the 6 S-trait RCCs, 3/6 units were within the HCT, HGB and hemolysis thresholds set by the CS. The modified deglycerolization protocol provides a path for the routine cryopreservation of S-trait RBCs.

Survival of transfused red blood cells from a donor with alpha-thalassemia trait in a recipient with sickle cell disease.

Post-transfusion survival of donor red blood cells (RBCs) is important for effective chronic transfusion therapy in conditions including sickle cell disease (SCD). Biotin labeling RBCs allows direct in vivo measurement of multiple donor RBC units simultaneously post-transfusion. In an observational trial of patients with SCD receiving monthly chronic transfusion therapy, aliquots of RBCs from one transfusion episode were biotin-labeled and infused along with the unlabeled RBC units. Serial blood samples were obtained to measure RBC survival. Donor units were tested for RBC indices, hemoglobin fractionation, and glucose-6-phosphate dehydrogenase (G6PD) enzyme activity. For microcytic donor RBCs (MCV < 70 fL), HBA1 and HBA2 genetic testing was performed on whole blood. We present one recipient, a pediatric patient with SCD and splenectomy who received two RBC units with aliquots from each unit labeled at distinct biotin densities (2 and 18 μg/mL biotin). One donor unit was identified to have microcytosis (MCV 68.5 fL after biotinylation); whole blood sample obtained at a subsequent donation showed 2-gene deletion alpha-thalassemia trait (ɑ-3.7kb/ɑ-3.7kb) and normal serum ferritin. G6PD activity was >60% of normal mean for both. The RBCs with alpha-thalassemia RBC had accelerated clearance and increased surface phosphatidylserine post-transfusion, as compared with the normocytic RBC (half life 65 vs. 86 days, respectively). Post-transfusion RBC survival may be lower for units from donors with alpha-thalassemia trait, although the impact of thalassemia trait donors on transfusion efficacy requires further study.

The use of intracellular dyes to create a multiplexed flow cytometry-based red blood cell phenotyping assay.

Flow cytometry can be used to phenotype red blood cell antigens, allowing for high-throughput testing while using low reagent volumes. This article utilizes intracellular dyes to pre-label red blood cells to further multiplex flow cytometry-based red blood cell antigen phenotyping. Red blood cells were pre-labelled using the intracellular dyes V450 and Oregon Green. These dyes are detected fluorescently via flow cytometry. Four combinations of intracellular staining were used to allow four patient or donor red blood cells to be analysed in a single test well. Antigen phenotyping was then performed via flow cytometry using a previously described method. The intracellular dyes showed uniform staining when measured in mean fluorescence intensity and allowed the red blood cells to be clearly distinguished from one another. The presence or absence of red blood cell antigens was determined with 100% accuracy. The use of intracellular dyes allowed a fourfold increase in the throughput of our previously described flow cytometry-based red blood cell antigen phenotyping method. The described method allows up to 48 patients to be simultaneously phenotyped using a single 96-well microplate. Furthermore, additional fluorescent dyes could potentially increase the throughput exponentially.

Study of Alloimmunization in Transfusion-dependent Thalassemia Patients at a Tertiary Care Hospital

Abstract: BACKGROUND: Alloantibodies against donor red blood cells (RBCs) are developed by patients with transfusion-dependent thalassemia (TDT), which causes the donor RBCs to hemolyze. This decreases the transfusion’s efficacy and increases the risk of adverse effects like iron overload. MATERIALS AND METHODS: Two hundred and five TDT patients with an average age of 11 ± 6 years enrolled in this study underwent the Direct Coombs Test (DCT) to determine the frequency of alloimmunization. RESULTS: Most cases were of thalassemia major (TM) (76.09%), followed by thalassemia intermedia (TI) and (21.95%). Most of the cases were diagnosed and started on regular blood transfusion therapy between the ages of 1 and 10 years. Majority of the cases were born of parental consanguinity. Only 13.17% of the patients underwent splenectomy, of which TM cases were the majority. Even though O-positive was the most frequent blood type, most of the operated and alloimmunized cases belonged to the B-positive blood type. Only 10.24% of the patients had alloimmunization, with 51.85% of them developing it after splenectomy. Among all study participants, no correlation was found between the blood group and the type of thalassemia, alloimmunization, or splenectomy. Among TDT cases, there was a significant correlation (P &lt; 0.0001) between alloimmunization and splenectomy. Alloimmunization and splenectomy correlated significantly with the total number of transfusions, the volume of blood transfused, and the transfusion initiation age. CONCLUSION: Our findings emphasize the significance of antigen typing in TDT patients before the first transfusion.

A machine-learning method for biobank-scale genetic prediction of blood group antigens.

A key element for successful blood transfusion is compatibility of the patient and donor red blood cell (RBC) antigens. Precise antigen matching reduces the risk for immunization and other adverse transfusion outcomes. RBC antigens are encoded by specific genes, which allows developing computational methods for determining antigens from genomic data. We describe here a classification method for determining RBC antigens from genotyping array data. Random forest models for 39 RBC antigens in 14 blood group systems and for human platelet antigen (HPA)-1 were trained and tested using genotype and RBC antigen and HPA-1 typing data available for 1,192 blood donors in the Finnish Blood Service Biobank. The algorithm and models were further evaluated using a validation cohort of 111,667 Danish blood donors. In the Finnish test data set, the median (interquartile range [IQR]) balanced accuracy for 39 models was 99.9 (98.9-100)%. We were able to replicate 34 out of 39 Finnish models in the Danish cohort and the median (IQR) balanced accuracy for classifications was 97.1 (90.1-99.4)%. When applying models trained with the Danish cohort, the median (IQR) balanced accuracy for the 40 Danish models in the Danish test data set was 99.3 (95.1-99.8)%. The RBC antigen and HPA-1 prediction models demonstrated high overall accuracies suitable for probabilistic determination of blood groups and HPA-1 at biobank-scale. Furthermore, population-specific training cohort increased the accuracies of the models. This stand-alone and freely available method is applicable for research and screening for antigen-negative blood donors.

Transfusion of ever-pregnant donor red blood cells and mortality of male patients.

Previous studies found exposure to red blood cell transfusions from female donors who have been pregnant reduces survival in male patients compared to exposure to male donor products, but evidence is not consistent. We postulate the previously observed association is modified by offspring sex, with an expected increased mortality risk for male patients receiving units from female donors with sons. Here, marginal structural models were used to assess the association between exposure to units from ever-pregnant donors, ever-pregnant donors with sons and ever-pregnant donors with daughters, and mortality. Clinical data were collected on first-ever transfusion recipients in the Netherlands and donor data were supplemented with information about offspring sex and date of birth. In this analysis, 56,825 patients were included, of whom 8,288 died during follow-up. Exposure to red blood cell units from ever-pregnant donors with sons was not associated with increased all-cause mortality risk among male transfusion recipients (hazard ratio [HR]=0.91, 95% confidence interval [CI]: 0.83-1.01). Exposure to ever-pregnant donors, irrespective of offspring sex, was associated with mortality in male patients aged between 18 and 50 years (ever-pregnant donors: HR=1.81, 95% CI: 1.31-2.51) compared to male donor units, but was protective in female patients. This study suggests that the observed increased mortality risk for exposure to red blood cell units from parous female donors does not depend on offspring sex. The increased risk of mortality seen in younger adult male patients is consistent with previous observations, but the underlying biological mechanism could not be identified in this study.

Distinct RBC alloantibody responses in type 1 interferon-dependent and -independent lupus mouse models.

During transfusion of red blood cells (RBCs), recipients are exposed to both ABO and non-ABO 'minor' antigens. RBC donor units and recipient RBCs are not routinely matched for non-ABO antigens. Thus, recipients are exposed to many RBC alloantigens that can lead to RBC alloantibody production and subsequent clinically significant hemolysis. RBC alloantibodies also significantly limit the provision of compatible RBC units for recipients. Prior studies indicate that the frequency of RBC alloimmunization is increased during inflammatory responses and in patients with autoimmune diseases. Still, mechanisms contributing to alloimmune responses in patients with autoimmunity are not well understood. More than half of adult patients with systemic lupus erythematosus (SLE) produce type 1 interferons (IFNα/β) and express IFNα/β stimulated genes (ISGs). Previously, we reported that IFNα/β promote RBC alloimmune responses in the pristane mouse model, which develops a lupus-like phenotype that is dependent on IFNα/β signaling. However, it is unclear whether IFNα/β or the lupus-like phenotype induces alloimmunization in lupus models. Therefore, we tested the hypothesis that IFNα/β promotes RBC alloimmune responses in lupus by examining alloimmune responses in IFNα/β-independent (MRL-lpr) and IFNα/β-dependent (pristane) lupus models. Whereas pristane treatment significantly induced interferon-stimulated genes (ISGs), MRL-lpr mice produced significantly lower levels that were comparable to levels in untreated WT mice. Transfusion of murine RBCs that express the KEL antigen led to anti-KEL IgG production by pristane-treated WT mice. However, MRL-lpr mice produced minimal levels of anti-KEL IgG. Treatment of MRL-lpr mice with recombinant IFNα significantly enhanced alloimmunization. Collectively, results indicate that a lupus-like phenotype in pre-clinical models is not sufficient to induce RBC alloantibody production, and IFNα/β gene signatures may be responsible for RBC alloimmune responses in lupus mouse models. If these findings are extended to alternate pre-clinical models and clinical studies, patients with SLE who express an IFNα/β gene signature may have an increased risk of developing RBC alloantibodies and may benefit from more personalized transfusion protocols.

Management of Delayed Hemolytic Transfusion Reaction in a Patient with Sickle Cell Disease: A Case Report

Background: Sickle cell disease (SCD) is a group of inherited blood disorders characterized by abnormalities in hemoglobin (Hb), leading to distortion in shape of red blood cells (RBCs) and their breakdown, potentially blocking blood flow and resulting in pain and anemia. This can significantly impact the patient’s quality of life. Patients often require multiple blood transfusions to prevent complications associated with SCD by reducing the concentration of damaged hemoglobin. However, one of the significant complications of blood transfusions is Delayed Hemolytic Transfusion Reaction (DHTR), which occurs due to RBC alloimmunization (i.e., formation of antibodies against donor RBC antigens). DHTR can manifest as a sudden decrease in hemoglobin levels, which may progress to rapid multiorgan failure and death. Thus, prompt diagnosis is crucial for timely management. This case report highlights the diagnosis and management of a 56-year-old African American female with SCD who presented with bilateral severe knee pain and low Hb levels. Case Presentation: The patient’s symptoms, past medical history, and investigation findings led to a diagnosis of DHTR. Management was conducted within the framework of Bloodless Medicine, incorporating strategies to minimize blood loss and optimize erythropoiesis. Treatment included the use of erythropoietin (EPO) to manage hemoglobin levels and the administration of opioids and supplemental oxygen for symptom relief. Conclusion: Our case report highlights the challenges and various management strategies employed in treating DHTR in SCD patients. It emphasizes the importance of early recognition of the complication and compares the risks and benefits of additional blood transfusions in such patients. By presenting this case, we aim to contribute to the growing literature on DHTR in SCD patients and highlight the need for further research and optimized management strategies in this population.

A Study of Red Cell Exchange in Patients of Sickle Cell Disease at a Tertiary Care Hospital of South Gujarat, India

ABSTRACT Introduction: Sickle cell disease (SCD) is an inherited single-gene autosomal recessive disorder. Red cell exchange (RCE) refers to the removal of diseased red blood cells (RBCs) in exchange for healthy donor RBCs. In the present study, RCE was performed in patients with SCD with different crises such as acute chest syndrome, vaso-occlusive crisis, and sequestration crisis. The study was conducted to determine the clinical efficacy of RCE in SCD and to study the clinical profile of the study population. The study will help generate data to support and improve existing knowledge on the clinical efficacy of RCE in SCD. Methods: A prospective observational study of RBC exchange in patients of SCD with the acute crisis was conducted at a tertiary care hospital in South Gujarat including the effect of RCE as a treatment modality in patients of SCD. The study was conducted following guidelines given by the American Society for Apheresis. Results: This study was conducted among 8 patients (7 female and 1 male) with varying age groups from 10 to 29 years. Clinical findings of patients, pulse rate, respiratory rate, and oxygen saturation got improved after the procedure. There was an improvement in PaO2 from 51.63 to 73 after the procedure. There was a decrease in mean sickle hemoglobin (Hb S) level (from 68.452% to 16.438% after procedure) and Hb F level (from 11.938% to 3.063% after procedure) with an increase in Hb A level (from 13.862% to 70.152% after procedure). Conclusion: In the present study, automated RCE procedures in patients with SCD were well tolerated and effective for both acute and chronic complications of SCD in terms of relieving the symptoms by reducing the Hb S level postprocedures.