Hemolytic Transfusion Reactions Research Articles

Red Cell Alloimmunization Is Associated with Higher Treatment Costs and Poor Health Outcomes Among Hemoglobin S-Beta Thalassemia Patients

Hemoglobin S (HbS) beta thalassemias (thal) are types of sickle cell disease (SCD) that result from the inheritance of one HbS gene and one β thalassemia gene. Red Blood Cell (RBC) alloimmunization is believed to be a major complication of transfusion therapy for HbS-thal patients. Indeed, among SCD patients generally, alloimmunization not only complicates the procurement of blood, but can also lead to life threatening delayed hemolytic transfusion reactions, and can be associated with a host of negative health outcomes including a higher risk of death. It is generally accepted that some alloimmunization events can be prevented via donor-recipient antigen matching, although this strategy is associated with higher costs and utilization of scarce resources (i.e.. antigen negative RBC units). The present study aimed to assess the clinical and economic implications of alloimmunization in HbS-thal patients.The Premier Hospital chargemaster dataset was used to perform a cross-sectional study matching alloimmunized and non-alloimmunized patients based on sex, age, date of admission, and type of visit (outpatient vs. inpatient). All outpatient and inpatient discharges from Jan 2015 to Jun 2019 were included in the study. Because there is not a specific laboratory code to designate alloimmunization, presence of both “antiglobulin crossmatch” and “RBC antibody identification” codes in a record was used as a surrogate for alloimmunization. Accuracy of this approach was validated by comparing the frequency of these codes among the hereditary hemorrhagic telangiectasia (HHT) and myelodysplastic syndromes (MDS) populations within the Premier dataset to the reported rates of alloimmunization for these entities in the medical literature (Zheng Transfusion. 2018;58(3):775-780, Singhal Haematologica. 2017;102(12):2021-2029). This comparison predicted a 16.8% alloimmunization rate in the HHT population (similar to the 15.3% reported in the literature) and an 11.5% alloimmunization prevalence in the MDS population (similar to the 11% reported in the literature).HbS-thal patients were identified based on diagnostic coding (ICD-10 code D57.4). Demographic, clinical and billing characteristics were retrieved. Cost per outpatient and inpatient discharge, hospital and intensive care unit (ICU) length of stay (LoS) and inpatient mortality were assessed for both alloimmunized and non-alloimmunized HbS-thal patients. Bivariate comparisons were performed, assuming a two-tailed test of significance and an α level of 0.05. Multivariable regression models adjusting for diagnosis-related groups with ≥1% incidence were performed.This approach permitted a total of 999 discharges corresponding to alloimmunized HbS-thal patients (cases) to be matched to 550 HbS-thal controls. Mean (SD) age was 35.1 (18.8) and 30.1 (18.6) for cases and controls, respectively. The percentage of females was slightly higher within the alloimmunized group (63.66% vs. 57.45%), and higher rates of inpatient visits were observed for the alloimmunized population compared to controls (67.9% vs. 33.1%).The multivariate models showed that alloimmunized HbS-thal patients presented significantly worse economic and clinical outcomes compared to their non-alloimmunized controls through all variables assessed. Median cost per discharge was $5,313 (p<0.0001) higher for alloimmunized inpatients and $1,014 (p<0.0001) higher for alloimmunized outpatients, compared to non-alloimmunized controls. Alloimmunized HbS-thal patients also experienced a 63% increase in hospital LoS (4.5 vs 7.4 days;; p<0.0001) and nearly over a 2.5-fold increase in ICU LoS (4.2 vs 10.0 days; p=0.0257). Alloimmunization in this population was also associated with a 3-fold increased risk of admission to intensive care (p=0.0032), longer stays in the ICU (p-0.0257), and a 3-fold increase in inpatient death (p<0.0001) (Table 1).The present study reveals that alloimmunization is associated with significantly longer hospitalizations and ICU stays, higher risk of ICU admission, greater inpatient death, and higher healthcare costs among patients with ICD-10 diagnosis of HbS-thal. These data seem to support the incremental costs and resource allocation decisions required to provide prophylactic antigen matching to HbS-thal patients, in an effort to diminish the risk of alloimmunization. [Display omitted] DisclosuresGehrie: Grifols SSNA: Consultancy, Honoraria. Viayna: Grifols S.A.: Current Employment. Blanchette: Grifols SSNA: Consultancy; Novo Nordisk Inc.: Current Employment. Meny: Grifols SSNA: Current Employment. Noumsi: Grifols SSNA: Current Employment. Huber: Grifols SSNA: Current Employment. Runken: Grifols SSNA: Current Employment.

Impact of Alloimmunization in Patients with Sickle Cell Disease

INTRODUCTIONBlood transfusion is an essential therapeutic and prophylactic component in the management of sickle cell disease (SCD) and associated complications. Prolonged transfusion therapy can lead to the development of antibodies to the donor's RBC antigens (alloimmunization), causing complications such as delayed hemolytic transfusion reactions, hyperhemolysis, worsening vaso-occlusive episodes, and end-organ damage. There have been only a few case series highlighting the impact of RBC alloimmunization on SCD morbidity and mortality, proposing a pathway involving RBC alloimmunization and decreased survival associated with hemolytic reactions or difficulty obtaining compatible blood when needed. However, apart from the consequences of iron overload, there is no long-term data for alloimmunization highlighting the clinical consequences, multiorgan damage, or associated morbidity in sickle cell patients.AIMThe primary aim is to investigate the incidence of alloimmunization in SCD patients in an academic health system. The secondary aim is to elucidate the differences in demographics, frequency of vaso-occlusive crisis, end-organ damage, and inflammatory markers between alloimmunized and non-alloimmunized SCD patients.METHODSWe conducted a retrospective multicentric descriptive study, including all sickle cell patients treated in an academic health system from January 1st, 2009, to December 31st, 2020, in Maryland, Virginia, and Washington, DC. An exemption from the Institutional Review Board for obtaining individual subjects' consent was procured. Patients included in the study were older than 18 years and diagnosed with sickle cell disease. Patients who did not have sickle cell disease were excluded from the study. Statistical analysis was reported using means for descriptive data, t-test for continuous variables, and chi-square for categorical variables.RESULTSA total of 94 patients with sickle cell disease were included in the study. Of these, 24 (25.5%) patients were found to have alloimmunization, whereas 70 (74.4%) patients did not. Of the alloimmunized patients, the average age, BMI and BSA were 30.15 years (p=0.037), 23.15 kg/m2 (p=0.040), and 1.65 m2 (p=0.003) compared to 37.07 years, 26.17 kg/m2 and, 1.84 m2 respectively among the non-alloimmunized group. 83% of the alloimmunized patients had sickle cell anemia (Hb SS), and 17% had a sickle thalassemia phenotype (p=0.005). A lower baseline hemoglobin (Hb) value of 8.01 g/dL was seen among alloimmunized patients compared to a higher Hb value of 9.63 g/dL (p=0.001) among the non-alloimmunized. Alloimmunized patients had an average of 5.55 alloantibodies. The average number of vaso-occlusive crises per year and related hospitalizations was statistically significantly higher in the alloimmunized group with 4.82 and 3.78, respectively, compared to 2.34 (p=0.035) 1.01 (p=0.0005) in the non-alloimmunized group. Similarly, the incidence of other sickle cell-related complications were higher among the alloimmunized patients, such as priapism (29% vs. 9%; p=0.0139), pulmonary hypertension (38% vs. 9%; p=0.0038) with no statistical difference in the iron overload (25% vs. 11%; p=0.150) or ferritin levels (. 83% of alloimmunized patients had a history of narcotic use vs. 34% among the non-alloimmunized (p=0.0001). Higher use of disease-modifying therapies including hydroxyurea (71% vs. 31%; p=0.0009) and voxelotor (13%vs0; p=0.0029), were also seen among alloimmunized patients. While no statistically significant difference was seen in the mean number of lifetime transfusions, there was a difference in the mean number of lifetime exchanges (3.67 vs. 0.0; p=0.0208).CONCLUSIONThe prevalence of alloimmunization in sickle cell patients in our study population (25.5%) was higher than in the literature (7- 59%) and the general population (2%). An increase in alloimmunization was associated with an increased number of exchanges but not with simple transfusions. Independent from the iron overload, alloimmunization was associated with increasing end-organ damage and sickle cell complications such as priapism, pulmonary hypertension. Strategies to decrease alloimmunization are needed to prevent these complications. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Preventing alloimmunization using a new model for matching extensively typed red blood cells.

Alloimmunization is a well-known adverse event associated with red blood cell (RBC) transfusions, caused by phenotype incompatibilities between donor and patient RBCs that may lead to haemolytic transfusion reactions on subsequent transfusions. Alloimmunization can be prevented by transfusing fully matched RBC units. Advances in RBC genotyping render the extensive typing of both donors and patients affordable in the foreseeable future. However, the exponential increase in the variety of extensively typed RBCs asks for a software-driven selection to determine the 'best product for a given patient'. We propose the MINimize Relative Alloimmunization Risks (MINRAR) model for matching extensively typed RBC units to extensively typed patients to minimize the risk of alloimmunization. The key idea behind this model is to use antigen immunogenicity to represent the clinical implication of a mismatch. Using simulations of non-elective transfusions in Caucasian donor and patient populations, the effect on the alloimmunization rate of the MINRAR model is compared with that of a baseline model that matches antigens A, B and RhD only. Our simulations show that with the MINRAR model, even for small inventories, the expected number of alloimmunizations can be reduced by 78.3% compared with a policy of only matching on antigens A, B and RhD. Furthermore, a reduction of 93.7% can be achieved when blood is issued from larger inventories. Despite an exponential increase in phenotype variety, matching of extensively typed RBCs can be effectively implemented using our MINRAR model, effectuating a substantial reduction in alloimmunization risk without introducing additional outdating or shortages.

The Immunohematologic and Clinical Evaluation of Increased Risk for Red Blood Cell Alloimmunization among Multi-Transfused Pediatric Patients in a Tertiary Medical Institution in Central Luzon, Philippines

Abstract Introduction/Objective Multiple blood transfusion is a therapeutic treatment for patients with hematologic disorders. However, patients who undergo repeated blood transfusions are at higher risk of developing red blood cell alloimmunization. This may further delay the availability of compatible blood and pose a higher risk for hemolytic transfusion reactions. Methods/Case Report A total of 55 patients, with an age range of 2-19 years, were included in the study. All patients had hematologic disorders and underwent chronic blood transfusion. In this retrospective study, Student’s t-test and Fisher’s exact tests were used to compare the means and percentages, respectively, under 5% level of significance. R ver 4.0.3 was utilized in the analyses. Results (if a Case Study enter NA) Out of the 55 pediatric patients, 10 (18.2%; CI95%: 9.1 to 30.9%) were found to be alloimmunized. Two patients had multiple antibodies whereas the others had one specificity, having a total of 12 detected alloantibodies. The most prevalent alloantibody was anti-E (60%), followed by anti-Jka (20%), anti-Mia (20%), anti-S (10%), and anti-K (10%). All obtained alloantibodies showed no correlation (p&amp;gt;0.05) with the age group of the patients. Subsequently, it was not evident that average blood transfusion (p=0.949) and packed red blood cells transfused per year (p=0.782) significantly differ between alloimmunized and non-alloimmunized patients. Similarly, there was no sufficient evidence that the age group (p=0.723), sex (p=1.000), blood group (p=1.000) and hematologic disorder (p=0.949) were associated with their alloimmunization status. Conclusion The alloimmunization incidence rate of 18.2% in this study was higher compared to related literatures, and most of the detected alloantibodies were of IgG type which are commonly clinically significant. The study showed no significant correlation between the specific risk factors and the development of alloimmunization. For patient care, it is imperative to include precautions such as extended RBC phenotyping and provision of antigen matched RBCs to prevent unnecessary transfusion reactions caused by alloimmunization.

Preventive Effect of Irregular Antibody Screening in Hemolytic Transfusion Reaction

Preventive Effect of Irregular Antibody Screening in Hemolytic Transfusion Reaction

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.

Safety and Feasibility of Home Transfusions in Pediatric Palliative Care: A Preliminary Report

BackgroundWhile hematological symptoms are considered difficult to manage in a Pediatric Palliative Care setting, home may still represent a safe and convenient place for transfusions in patients with advanced malignancy or chronic conditions. This research focuses on the safety and feasibility of a home transfusion program. MethodsThis is a case series of patients between 0 and 18 years diagnosed with advanced malignancy or incurable chronic conditions and eligible to Pediatric Palliative Care who received home platelet or packed red cell transfusions. For all patients, we recorded adverse events such as acute hemolytic reactions, allergic reactions, or any emergency condition requiring hospital admission, equipment failure, blood product transport or storage errors, errors in patient identification, and personnel safety issues. We explored parental satisfaction with a Likert-type questionnaire and short open questions. ResultsWe reviewed 101 transfusion procedures for six patients in Pediatric Palliative Care performed by the Regional Pediatric Palliative Care network between 2014 and 2020. We did not report any adverse effects. Families reported satisfaction and a sense of safety and positively evaluated the opportunity of having transfusion at home to minimize the disruption in everyday life. The cost analysis resulted in a consistent saving for the Regional Health System. ConclusionThis study supports the safety and feasibility of home transfusion in Pediatric Palliative Care.

RHD Genotyping of Rh-Negative and Weak D Phenotype among Blood Donors in Southeast Iran

Background: The D antigen is a subset of Rh blood group antigens involved in the hemolytic disease of the newborn [HDFN] and hemolytic transfusion reaction [HTR]. The hybrid Rhesus box that was created after RH gene deletion, was known as a mechanism of the Rh-negative phenotype. Hybrid marker identification is used to confirm the deletion of the RHD gene and to determine zygosity. This study aims to detect this marker in Rh-negative and weak D phenotype blood donors of the southeast of Iran. Materials and Methods: The molecular analysis of the hybrid Rhesus box was performed on the 200 Rh-negative blood donors in Sistan and Baluchestan province, southeast Iran. The presence of alleles responsible for the D variants was assessed by DNA sequencing in 26 weak D phenotype donors. Results: Of the 200 Rh-negative blood samples, 198 samples were homozygous (99%), and two samples were heterozygous (1%). Heterozygous samples had RHD*01N.73 allele and the RHD*01N.18 allele. Of the 26 samples with weak D phenotype, 16 partial DLO (61%), 4 partial DBT1 (15.3%), 2 partial DV type 2 (7.7%), 1 weak D type 1, 1 weak D type 4.2.3, 1weak D type 105 and 1 RHD (S103P) (4%) were determined. Conclusion: Since RHD gene deletion is the main mechanism of the Rh-negativity in Sistan and Baluchestan provinces, a hybrid Rhesus box marker can be used in resolving RhD typing discrepancies by RHD genotyping methods.

COMPARISON OF PROPHYLACTIC GENOTYPIC MATCHING WITH PHENOTYPIC MATCHING FOR REDUCING THE RATE OF ALLOIMMUNIZATION AND HEMOLYTIC TRANSFUSION REACTIONS IN PATIENTS WITH SICKLE CELL DISEASE (SCD)

Patients with SCD are among one of transfused populations more often alloimmunized to red blood cell (RBC) antigens. Although transfusion services establish protocols of serologic matching and genotypic matching to reduce alloimmunization, there is still no consensus to the best practical approach although the obvious goal is to provide blood that will survive maximally. There are no studies comparing prophylactic genotypic matching to serologic matching. Based on this, our aim was to evaluate the effect prophylactic genotypic matching and serologic matching have on alloimmunization and hemolytic transfusion reactions in patients with SCD receiving regular transfusions. A prospective study was conducted in 29 patients with SCD undergoing red cell transfusions in a period of 5 years. Fifteen patients were receiving prophylactic extended (ABO, Rh, K, Fy a /Fy b , S/s) serologic matching and 14 patients were transfused with RBC units genotypic matched for Rh, K, Fy a /Fy b , S/s, Di a , Do a /Do b including Rh variants when possible. Serologic typing was performed by gel test (Biorad) and genotyping was performed by HEA, RHD and RHCE BeadChips (Immucor). The patients received a range of 15-407 RBC units and the median age was 36. Of the 15 patients receiving prophylactic serologic matching, 6 developed alloantibodies (1 anti-D, 2 anti-e, 1 anti-S, 1 anti-Fy a , -Do a and 1 anti-C, -Di a ). Three of those patients were not having a good in vivo RBC survival at the time of antibody detection as assessed by a decrease in their hemoglobin levels and an increase in the frequency of transfusions. Molecular analyses showed that the 4 patients who developed Rh antibodies had RH variant alleles predicting partial antigens and the patients who developed anti-S and anti-Fy a had discrepancies between the previous phenotype and genotype-derived phenotype. Of the 14 patients transfused with prophylactic genotypic matching RBC units, 2 were alloimmunized to Rh antigens (1 anti-D, 1 anti-e). Unexpected Rh antibodies found in these patients were not linked to expression of partial Rh phenotypes according to serological and molecular analyses but a result of altered Rh epitopes on transfused red cells. Our results showed that prophylactic genotypic matching is superior to phenotypic matching in patients with SCD especially if RH molecular matching is included, with the potential to decrease risk of transfusion reactions and to prevent alloimmunization.

Utility of type and screen policy for pretransfusion compatibility testing at an urban level Ι apex trauma center

Objective: Type and crossmatch (TC) policy is the most common approach for pre-transfusion compatibility testing prior to issue of blood for transfusion. As it involves reserving of the blood units (usually up to 72 hours) prior to issue or un-reserving, it can lead to excessive blood cross matching, inventory management problems, undue workload, blood outdating and reagent wastage. Type and screen (TS) policy is an alternative approach without the need to cross match and reserve blood units prior to issue. The aim of the current study was to retrospectively assess the impact of the implementation of TS policy for pre-transfusion compatibility testing on blood transfusion services at an urban level Ι trauma center. Methods: The study was done in two phases in the Department of Transfusion Medicine at Jai Prakash Narayan Apex Trauma Center AIIMS, New Delhi, India. Transfusion data was collected and compared during two phases: initial phase (Oct 2016-Mar 2017) of TC policy and second phase (Apr 2017-Sept 2017) of TS policy. Results: TS policy resulted in the reduction of C:T ratio from 5.3 to 1.9. Transfusion probability increased to 29.5% during TS policy from 23.6% during TC policy. Issuable stock index (ISI) also showed reduction from 12.5 to 11.4 after TS policy. Wastage as percentage of issue (WAPI) was reduced from 2.3% (TC) to 1.3% (TS). TS policy also led to reduction in expenses incurred on pre-transfusion compatibility testing by 35%. No hemolytic transfusion reaction was reported during the study. Conclusion: TS policy was found to be a safe and an efficient alternative approach to TC policy for pre-transfusion compatibility at our center. We recommend the implementation of TS policy, but each center should first assess its feasibility based on patient population, blood bank resources and staff knowledge.

Molecular red cell genotyping of rare blood donors in South Africa to enhance rare donor-patient blood matching.

BackgroundMolecular red cell genotyping is devoid of serology limitations such as the scarcity of rare antisera and the possibility of inconclusive results due to biological interferences. Blood incompatibility can result in immune transfusion reactions such as haemolytic transfusion reactions or haemolytic disease of the foetus and newborn.ObjectiveThe study aimed to use molecular red cell genotyping to identify rare blood group donors among South African blood donors.MethodsRed cell genotyping data were extracted retrospectively from the BIDS XT genotyping software in the Immunohaematology Reference Laboratory from January 2015 to August 2016. The ID CORE XT genotyping assay was used to identify the single nucleotide polymorphisms of 10 blood groups system alleles in 150 donors. Associations between the resultant genotypes and predicted phenotypes, ABO group, RhD type, race group and gender were studied.ResultsSignificant red cell genetic variability was noted among the numerous South African donor genotypes identified in this study. Genotyping further confirmed the presence of at least one of the 16 rare genotypes in 50 donors. Group O Black donors were associated with two rare blood types, while several other rare blood types were found only in White donors, supporting an association between ABO/Rh subtype, race group and rare blood types.ConclusionTargeted screening of donors for antigen-negative rare blood units for patients should be done to reduce the risk of haemolytic transfusion reactions and haemolytic disease of the foetus and newborn.

PIGG defines the Emm blood group system

Emm is a high incidence red cell antigen with eight previously reported Emm− probands. Anti-Emm appears to be naturally occurring yet responsible for a clinically significant acute hemolytic transfusion reaction. Previous work suggests that Emm is located on a GPI-anchored protein, but the antigenic epitope and genetic basis have been elusive. We investigated samples from a South Asian Indian family with two Emm− brothers by whole genome sequencing (WGS). Additionally, samples from four unrelated Emm− individuals were investigated for variants in the candidate gene. Filtering for homozygous variants found in the Emm− brothers and by gnomAD frequency of < 0.001 resulted in 1818 variants with one of high impact; a 2-bp deletion causing a frameshift and premature stop codon in PIGG [NM_001127178.3:c.2624_2625delTA, p.(Leu875*), rs771819481]. PIGG encodes for a transferase, GPI-ethanolaminephosphate transferase II, which adds ethanolamine phosphate (EtNP) to the second mannose in a GPI-anchor. The four additional unrelated Emm− individuals had various PIGG mutations; deletion of Exons 2–3, deletion of Exons 7–9, insertion/deletion (indel) in Exon 3, and new stop codon in Exon 5. The Emm− phenotype is associated with a rare deficiency of PIGG, potentially defining a new Emm blood group system composed of EtNP bound to mannose, part of the GPI-anchor. The results are consistent with the known PI-linked association of the Emm antigen, and may explain the production of the antibody in the absence of RBC transfusion. Any association with neurologic phenotypes requires further research.

Phenotypic and Genetic Characterization for Incompatible Cross-Match Cases in the Feline AB Blood Group System.

The feline AB blood group system (blood types A, B, and AB) encoding the cytidine monophosphate-N-acetylneuraminic acid hydroxylase (CMAH) gene is the most significant in transfusion medicine and hemolysis of the newborn for cats. Blood typing and cross-matching in pre-transfusion testing are crucial to determining blood compatibility and thus prevent hemolytic transfusion reactions. We here performed serological and genetic investigations to characterize blood samples from cats with discordant results for card agglutination (CARD) and the alloantibody agglutination test for blood typing in two cats (subjects K and R). Subject K showed incompatible cross-matching in pre-transfusion testing. Red blood cells from subjects K and R determined blood type B from the CARD method showed blood type AB by alloanti-A and alloanti-B antibodies in agglutination testing. Genomic DNA sequencing of the coding region (exons 1a to 14) for the cat CMAH gene showed that subject K had four mutations with heterozygosity at c.139C>T, c.179G>T, c.327A>C, and c.364C>T. Similarly, the CMAH gene of subject R carried six mutations with heterozygosity at c.142G>A, c.187A>G, c.268T>A, c.327A>C, c.773G>A and c.1603G>A, representing a new diplotype including a novel synonymous single nucleotide polymorphism (SNP) in exon 7 (c.773 G>A: Arg258Gln). The CMAH diplotype in subjects K and R was different from major diplotype in blood type B cats. This study is the first to report CMAH variants in cats with discordant blood types between CARD and TUBE methods. These results could assist in the classification of feline AB blood types for transfusion medicine to avoid blood incompatibilities.

Immune erythrocyte antibodies in adult patients with sickle cell disease and blood donors in Lagos, Nigeria: a comparative study.

Abstract Sickle cell disease (SCD) poses a major public health challenge in sub-Saharan Africa, including Nigeria. Blood transfusion is a mainstay in SCD treatment. Erythrocyte alloimmunization is known to complicate the transfusional care of patients with SCD. Immune alloantibodies are associated with hemolytic transfusion reactions and transfusion refractoriness. We aimed to determine the prevalence, specificities, and clinical associations/risk factors of immune erythrocyte alloantibodies among adult patients with SCD compared with healthy blood donors in Lagos, Nigeria, through a cross-sectional study. All participants were interviewed using a structured questionnaire to obtain details on bio-data, hemoglobin phenotype, blood transfusion history, and SCD history where relevant. Blood specimens obtained from each participant were subjected to antibody screening/identification using tube agglutination method. The mean age of the SCD participants and healthy blood donors was 27.92 and 29.04 years, respectively. The majority (72.5%) of the SCD participants had received at least 1 unit of red blood cell (RBC) transfusion in their lifetime, compared with only 7.5 percent of blood donors. Six SCD participants (7.5%) tested positive for atypical erythrocyte alloantibodies, with none among blood donors. Most of the antibodies (75%) belonged to the Rh blood group system. The most frequent antibody was anti-E, followed by anti-C and anti-D. Advancing age (30 years or more), recent transfusions (last 4 weeks), higher transfusion rates, and established renal disease were significantly associated with alloimmunization (p values of 0.026, 0.043, 0.002, and 0.043, respectively). This study suggests blood transfusion as a strong risk factor for RBC alloimmunization in SCD patients. Extended RBC phenotyping is recommended for all patients with SCD, especially those receiving regular transfusions.

Rh antibodies as a result of altered Rh epitopes on transfused red cells: a case series of seven Brazilian patients.

Rh antibodies produced by patients receiving Rh-matched RBC units may be associated with inheritance of altered RH alleles or a result of altered Rh epitopes on donor red blood cells (RBC). On this background, our aim was to evaluate unexpected Rh antibodies in Brazilian patients receiving regular transfusions and determine the clinical significance of the alloantibody produced. We investigated seven patients (5 with sickle cell disease, 1 with myelodysplastic syndrome and 1 with β-thalassaemia) with unexplained Rh antibodies. All patients had complete serological and molecular analyses. A lookback at the donor units transfused to these patients was performed and donors suspected of having Rh variants were recruited for further analysis. Laboratory and clinical findings were used to evaluate the clinical significance of the alloantibodies produced. The unexpected Rh antibodies found in the patients were not linked to the expression of partial Rh phenotypes according to serological and molecular analyses. Anti-D was found in two patients, anti-C was found in one patient, anti-c was found in one patient and anti-e was found in three patients carrying conventional D, C, c and e antigens respectively. Serological and molecular analyses of donors' samples revealed that six donors whose RBC were transfused to these patients carried partial Rh antigens. Only one anti-e in a patient with β-thalassaemia was autoreactive and could not be explained by RH diversity in his donors. Three of the seven Rh antibodies were associated with laboratory and clinical evidence of a delayed haemolytic transfusion reaction or decreased survival of transfused RBC at first detection. Our study provides evidence that patients exposed to RBC units from donors with Rh variants may develop antibodies and some of these may be of clinical significance.

A case of delayed hemolytic transfusion reaction found to be the D-- phenotype during burn treatment

A case of delayed hemolytic transfusion reaction found to be the D-- phenotype during burn treatment

The frequencies of Kidd blood group antigens and phenotypes among Saudi blood donors in Southwestern Saudi Arabia.

BackgroundThe patients who require transfusion are prevalent in the Jazan Province, Saudi Arabia. Therefore, it is essential to know the frequency of blood group antigens in such a population. The Kidd blood group system (JK) has two antithetical antigens, Jka and Jkb. Antibodies to these antigens may result in delayed hemolytic transfusion reactions. The present study investigated the frequencies of Jka and Jkb and the phenotypes among Saudi blood donors living in the Jazan Province.MethodsOne hundred and forty-three samples from anonymous Saudi volunteer blood donors in the Jazan Province were serotype to detect Jka and Jkb using gel card technology and determine the phenotypes of the JK blood group system.ResultsThe prevalence of Jka and Jkb antigens were 90.64% (n = 126) and 69.40% (n = 93), respectively. The JK phenotypes were 34.96% Jk(a + b − ) (n = 51), 12.59% Jk(a − b + ) (n = 18), 52.45% Jk(a + b + ) (n = 75), and 0% Jk(a − b − ). The frequencies of the JK phenotypes in the Jazan population were significantly different from those in the Asian population (P < 0.05).ConclusionsWe reported the frequencies of the Jka and Jkb antigens and the distribution of the JK phenotypes in a group of Saudi blood donors in the Jazan Province, Saudi Arabia. The phenotype Jk(a + b + ) was the most common among the study population. Furthermore, this study emphasizes the significance of identifying the frequency of JK antigens and phenotypes in the provinces of Saudi Arabia.

DELAYED HEMOLYTIC TRANSFUSION REACTIONS ( DHTR) AND HYPERHEMOLYSIS SYNDROME IN CHILDREN WITH SICKLE CELL DISEASE (SCD ) : A CASE REPORT: JUBAIL, KINGDOM OF SAUDI ARABIA

Delayed hemolytic transfusion reactions (DHTRs) occur in patients who have received transfusions in the past. These patients may have very low antibody titers that are undetectable on pretransfusion testing, so that seemingly compatible units of red blood cells (RBCs) are transfused. DHTRs are a potentially life-threatening complication of sickle-cell disease (SCD) treatment. In SCD, DHTRs appear to be an immune process that develop because of differences in erythrocyte antigens between blood donors and patients. Aim:DHTR is one of serious complication of blood transfusion that happens due to alloimmunized which is lead to hyperhaemolysis syndrome , DHTR can be managed by steroid and Intravenous immunoglobulin ( IVIG ) and prevented by accurate records with extended matching for certain population. Methodology: The consent of the patient and his family was obtained to publish and highlight his health condition in detail and to follow up with the case to match the research results and work on it under the framework of case reporting. Conclusion: DHTR can be managed by steroid and Intravenous immunoglobulin ( IVIG ) with good outcomes,DHTR can be prevented by means of accurate records, extended matching for certain population with high risk of developing alloantibodies such as individuals with SCD and B-thalassemia with proper handling of administration of blood product and proper notation in the patient medical records and blood bank records as well as the use of medical card for patient to known RBC alloantibodies.

Rapid detection of phenotypes Bombay sedel and nonsecretor rs200157007 SNP (302C\u2009>\u2009T) by real-time PCR-based methods

The sedel allele is one of the nonsecretor alleles (se) of FUT2 generated by an Alu-mediated recombination event and was first found in Indian Bombay phenotype individuals who have anti-H, anti-A, and anti-B antibodies in their serum. As well as anti-A, and anti-B antibodies, anti-H is clinically significant because it causes sever hemolytic transfusion reactions. Like sedel, se302 having a missense single nucleotide polymorphism (SNP), 302C > T, is characteristic of South Asians with a frequency of 10–30%. We developed a real-time PCR melting curve analysis for detection of sedel using a 127-bp amplicon encompassing the breakpoint junction. In addition, by performing duplex PCR by amplifying a 65-bp amplicon of the FUT2 coding region at the same time, we could determine the zygosity of sedel in a single tube. We also developed an Eprobe-mediated PCR assay (Eprobe-PCR) for detection of 302C > T of FUT2. These methods were validated by analyzing 58 Tamils and 54 Sinhalese in Sri Lanka. Both the duplex PCR melting curve analysis for determination of sedel zygosity and the Eprobe-PCR assay for detection of 302C > T exactly determined three genotypes. In addition, the results of the present methods were in complete agreement with those obtained by previously established methods. The two present methods were reliable and seem to be advantageous for large-scale association studies of FUT2 polymorphisms in South Asian populations.

Prevalence of Unexpected Red Cell Antibodies in Healthy Donor Population in a Tertiary Care Center in South Kerala

Background and Objectives: Apart from naturally occurring red cell antibodies Anti-A and Anti-B in human plasma, there are two types of unexpected red cell antibodies: Alloantibodies and auto-antibodies. The presence of these antibodies, alone or in combination, makes difficulties with compatibility testing, thereby delaying in the issue of a compatible blood unit or may reduce posttransfusion red blood cells life span. Antibody screening is mandatory as laid down by the Drug and Cosmetic Act 1940 and Directorate General of Health Services guidelines. This goal of this paper was to study the prevalence of Unexpected Red Cell Antibodies in Healthy Donor Population in a Tertiary Care Centre in South Kerala. Methods: The sample size chosen for this study was 7000 randomly chosen healthy nonremunerated voluntary donors who attended in house and blood donation camps over a period between November 26, 2017, and February 15, 2019. Results: The prevalence of unexpected red cell antibodies was found to be 1 in 1000. Male blood donations were more than female and blood donors among 18–30 years of age were greater in number. There were no cases of direct antiglobulin test positivity encountered. Male: Female ratio is 2.5:1 and males had naturally occurring alloantibodies, whereas females had a previous history of pregnancy. Anti-M and Anti-Lewis antibodies were the most common alloantibodies followed by Anti-Rh (D and C) antibodies and Anti-IH in the current study. Benign cold agglutinins (BCA) were found predominately in the younger male population with a significant seasonal variation noted in the prevalence of these antibodies. Conclusion: All antibodies identified had the ability to cause immune hemolytic transfusion reactions in the recipients. BCA-positive cases were seen more during the winter season and rainy seasons when compared to hot climatic conditions.