Hemolytic Transfusion Reactions Research Articles

Extended Phenotyping to Identify Blood Donors for an Institutional Rare Donor Registry

Abstract Background: Alloantibody formation to red cell antigens, sometimes seen in patients receiving multiple transfusions, are capable of causing hemolytic transfusion reactions when transfused with blood cells that are positive for the corresponding antigens. Providing them with red cells negative to these antigens becomes imperative. There is a need to have a pool of donors known to be negative for such antigens to provide blood units to such patients. Aim: The aim of the study is to identify rare donors in our population and register them for need-based blood unit collection for patients when phenotype-specific blood units are required. Methodology: Regular blood donors after consent were included for extended phenotyping for antigens c, C, e, E, K, k, Lea, Leb, Lua, Lub, P1, Kpa, Kpb, Jka, JKb, M, N, S, s, Fya, and Fyb by serological testing using monoclonal antisera. The phenotypes that were either negative for high-frequency antigens such as H, k, or multiple common antigen negative phenotypes were identified and enrolled as rare blood donors. Results: A total of 202 donors were completely phenotyped for the said 21 antigens. We identified 14 such donors, 7 of whom were high-frequency antigen-negative and 7 were multiple common antigen-negative phenotypes. The turnaround time for providing blood for patients requiring such units has drastically reduced with this initiative. A unit of such a rare phenotype was collected and shipped to Pune for a patient who required it within 24 h. Conclusion: Our findings highlight the need for a countrywide rare donor registry to coalesce the data from all centers with the facility for phenotyping. This will reduce the turnaround time of searching for donors for a particular phenotype, contributing to better patient care, and emergency management.

Dual Red Cell Alloimmunization with Anti-c and anti-E Antibodies

Background and Objectives: Alloimmunization can lead to difficulty in arranging compatible, antigen-negative blood units for the patients. Alloimmunization by coexisting “c” and “E” antibodies, though common, is frequently missed. Both “c” and “E” antigens are highly immunogenic and have the potential to cause hemolytic disease of newborn and hemolytic transfusion reactions. The objective of this study is to discuss different clinical scenarios of concomitant and singular presence of anti-c and anti-E along with the diagnostic approach and transfusion management in resource-limited settings. Methods: Column agglutination gel technology in low ionic strength solution phase was used for initial antibody identification. Detailed immunohematological workup was done by the use of select cells (c+, E− and c−, E+) and adsorption elution studies using a commercially available acid elution kit. Results: Out of 16 patients, detailed immunohematological workup was available for 14 patients, whereas two patients were lost to follow-up. Among 14 patients, 12 had CCDee (R1R1) phenotype, whereas two patients had CcDee phenotype (possible R1r) with anti-E antibody. In 12 patients with R1R1 phenotype, 6/12 (50%) had dual coexisting anti-c and E, whereas 3/12 (25%) had only anti-c and 3/12 (25%) had only anti-E. In R1R1 patients having anti-E, coexisting anti-c was found in 6/9 (66.66%) of patients. Conclusion: The study emphasizes the use of both “c” and “E” negative red cells (R1R1) in R1R1 patients having either anti-c or anti-E. Thus, in India, there is a need to develop our own red cell panels having an adequate representation of indigenous antigens and phenotypes.

Extended red blood cell phenotyping among regular donors in Fayoum, Egypt. Red Blood Cell Inventory Plan

Abstract Background Antibodies to clinically significant red cell antigens contribute to hemolytic transfusion reactions and hemolytic disease of fetus and newborn. The aim of the study was to estimate the prevalence of extended red cell antigen phenotypes among regular donors in Fayoum, Egypt, and to create an emergency model database for chronic transfusion patients. Similar data in Egypt is rare to find in the literature. Patients and methods The study was carried out over 1 year from December 2020 until November 2021in Fayoum University Hospital Blood Bank. In all, 1834 healthy known blood donor samples were analyzed for major Rh phenotypes (D, C, c, E, e) and for other clinically significant systems including Kell, Kidd, MNS, and Duffy. Results Phenotypic frequencies of Rh system were D+ (84.4%), e+ (79.6%), and C+ (63.9%). The K antigen frequency was 4.3%, Jka 79.4%, Jkb 62.37%, Fy a 33.2%, Fy b 44.4%, M antigen 88%, N antigen 38.6%, and the S and s antigens 48.2 and 85.3%, respectively. Conclusion Determination of red cell antigen phenotyping in Fayoum, Egypt, plays an important role in setting a routine phenotyping strategy for multiple transfused patients by keeping the donor database for rare phenotypes to prevent hemolytic transfusion reaction.

ZIF-8 metal organic framework nanoparticle loaded with tense quaternary state polymerized bovine hemoglobin: potential red blood cell substitute with antioxidant properties.

Due to several limitations associated with blood transfusion, such as the relatively short shelf life of stored blood, low risk of developing acute immune hemolytic reactions and graft-versus-host disease, many strategies have been developed to synthesize hemoglobin-based oxygen carriers (HBOCs) as universal red blood cell (RBC) substitutes. Recently, zeolite imidazole framework-8 (ZIF-8), a metal-organic framework, has attracted considerable attention as a protective scaffold for encapsulation of hemoglobin (Hb). Despite the exceptional thermal and chemical stability of ZIF-8, the major impediments to implementing ZIF-8 for Hb encapsulation are the structural distortions associated with loading large quantities of Hb in the scaffold as the Hb molecule has a larger hydrodynamic diameter than the pore size of ZIF-8. Therefore to reduce the structural distortion caused by Hb encapsulation, we established and optimized a continuous-injection method to synthesize nanoparticle (NP) encapsulated polymerized bovine Hb (PolybHb) using ZIF-8 precursors (ZIF-8P-PolybHb NPs). The synthesis method was further modified by adding EDTA as a chelating agent, which reduced the ZIF-8P-PolybHb NP size to <300 nm. ZIF-8P-PolybHb NPs exhibited lower oxygen affinity (36.4 ± 3.2 mm Hg) compared to unmodified bovine Hb, but was similar in magnitude to unencapsulated PolybHb. The use of the chemical cross-linker glutaraldehyde to polymerize bovine Hb resulted in the low Hill coefficient of PolybHb, indicating loss of Hb's oxygen binding cooperativity, which could be a limitation when using PolybHb as an oxygen carrier for encapsulation inside the ZIF-8 matrix. ZIF-8P-PolybHb NPs exhibited slower oxygen offloading kinetics compared to unencapsulated PolybHb, demonstrating successful encapsulation of PolybHb. ZIF-8P-PolybHb NPs also exhibited favorable antioxidant properties when exposed to H2O2. Incorporation of PolybHb into the ZIF-8 scaffold resulted in reduced cytotoxicity towards human umbilical vein endothelial cells compared to unloaded ZIF-8 NPs and ZIF-8 NPs loaded with bovine Hb. We envisage that such a monodisperse and biocompatible HBOC with low oxygen affinity and antioxidant properties may broaden its use as an RBC substitute.

Type and Screen Method versus Antihuman Globulin Crossmatch in Pretransfusion Testing: A Cross-sectional Study

Introduction: Blood transfusion remains the primary modality of treatment for many serious and common diseases. According to the International Society of Blood Transfusion (ISBT), there are about 349 blood group antigens, out of which only about 25-28 antigens are known to cause acute or delayed type of haemolytic transfusion reactions which could be prevented by Pretransfusion Testing (PTT). Regulated pretransfusion tests include ABO blood grouping, Rh typing, antibody detection, antibody identification and compatibility testing. The purpose of compatibility tests is to demonstrate invitro red cell antigen-antibody reaction. The Antihuman Globulin (AHG) crossmatch testing can assure ABO compatibility between donor and patient blood as well as detect most clinically significant antibodies. Type and Screen (T&amp;S) is a procedure carried out as part of PTT in which the recipient’s blood sample is tested for ABO group, RhD T&amp;S for unexpected antibodies. Aim: To compare T&amp;S method of PTT with AHG crossmatch. Materials and Methods: This cross-sectional study was conducted in the department of Transfusion medicine at Government Royapettah Hospital, Chennai and The Tamil Nadu Dr. MGR Medical University, Chennai, Tamil Nadu, India from June 2012 to December 2013. T&amp;S was performed on 1,040 recipients’ (510 males and 530 females) samples. All these samples were subjected to AHG crossmatch with ABO group and RhD type matched donor samples to assess the compatibility between donor and recipient by using column agglutination technology. Statistical analysis was carried out using Statistical Package for the Social Sciences (SPSS) version 11.0. Results: The prevalence of unexpected antibodies in the recipient population was 1.06%. Among the 1,040 recipients’ blood samples, 11 samples were found to have unexpected antibodies. Out of these 11 samples, 10 showed exact antibodies and the remaining one sample with negative antibody screening was found to be incompatible with AHG crossmatch. The sensitivity and specificity of T&amp;S method in comparison to AHG crossmatch was 87.50% and 99.71%, respectively. Conclusion: The sensitivity and specificity of T&amp;S is as acceptable as AHG crossmatch. However, in view of one sample with false negative antibody screening in the study population, it is imperative to know the phenotyping of Red Blood Cells (RBC) antigens of the native population before getting away with AHG crossmatch.

Delayed haemolytic transfusion reaction in paediatric patients with sickle cell disease: A retrospective study in a French national reference centre.

Delayed haemolytic transfusion reaction (DHTR) is a life-threatening haemolytic anaemia following red blood cell transfusion in patients with sickle cell disease, with only scarce data in children. We retrospectively analysed 41 cases of DHTR in children treated between 2006 and 2020 in a French university hospital. DHTR manifested at a median age of 10.5 years, symptoms occurred a median of 8 days after transfusion performed for an acute event (63%), before surgery (20%) or in a chronic transfusion programme (17%). In all, 93% of patients had painful crisis. Profound anaemia (median 49 g/L), low reticulocyte count (median 140 ×109 /L) and increased lactate dehydrogenase (median 2239 IU/L) were observed. Antibody screening was positive in 51% of patients, and more frequent when there was a history of alloimmunisation. Although no deaths were reported, significant complications occurred in 51% of patients: acute chest syndrome (12 patients), cholestasis (five patients), stroke (two patients) and kidney failure (two patients). A further transfusion was required in 23 patients and corticosteroids were used in 21 to reduce the risk of additional haemolysis. In all, 13 patients subsequently received further transfusions with recurrence of DHTR in only two. The study affords a better overview of DHTR and highlights the need to establish guidelines for its management in children.

Prevalence of Kell Ag in Pregnant Women with Thalassemia Minor or Intermedia Beta in Medical Centers Affiliated to Shiraz University of Medical Sciences in 2019-2020

Background: Kell Ag, the main antigen of kell system has the greatest antigenicity after Rh antigen and the associated antibodies are very important. These antibodies are mainly of the Ig G class and can cause side effects like Hemolytic disease of the Fetus and Newborn (HDFN) or Hemolytic Transfusion Reaction (HTR), especially in patients with chronic blood transfusions such as thalassemia patients. The aim of this study was to evaluate Kell antigen in pregnant women with thalassemia minor and intermedia and to determine the appropriate strategy for transfusion in this group of patients Methods: This study is a cross-sectional study on pregnant women with thalassemia minor or intermedia. The samples were taken from patients of Shahid Motahari clinic and those with positive antigen were selected and statistically analyzed. Results: The results showed that from the 64 patients who entered this study, the results of kell ag of 58 patients were negative and 6 were positive. Therefore, 91% of the pregnant women with beta thalassemia minor or intermedia were negative for ag kell and 9% were positive. Conclusion: In summary, the results of this study indicated that a large percentage of pregnant women with beta-thalassemia minor or intermediate are Kell-negative, and due to the complications of alloimmunization, screening of pack cells and pregnant patients is very important.

Development of Mia Phenotyping Using Paper-Based Device.

The MNS7 (Mia) blood group antigen is found at a different prevalence among different ethnic groups. Anti-Mia can cause hemolytic disease of the fetus and newborn (HDFN) and both acute- and delayed-type hemolytic transfusion reactions (HTR). Mia typing should be performed in donors to prevent life-threatening hemolytic transfusion reactions. The gel card and standard tube methods still need specialized equipment, centrifugation, and expertise for result interpretation. We used a novel paper-based analytical device (PAD) pre-coated with monoclonal IgM anti-Mia for Mia phenotyping. We measured grey pixel intensity in blood typing results for interpretation processing using OpenCV at the sample (SP) and elution parts (EP); furthermore, we used the SP: EP ratio and F-score as analysis criteria. We typed 214 blood EDTA samples with PAD-Mia and then compared with gel card results for setting an analysis criterion. We observed 100% sensitivity, specificity, and accuracy when we applied the SP: EP ratio and F-score with the optimal criterion (1.07 and 0.17 for SP: EP ratio and F-score, respectively). The validation of PAD-Mia typing for blood donor samples (n = 150) via F-score gave 100% sensitivity and specificity when compared with the gel card method; therefore, we argue that PAD-Mia typing can be used for Mia phenotyping without sero-centrifugation. Moreover, to study the correlation between genotype and phenotype, PCR-SSP was performed to identify GYP(B-A-B) hybrids. The results revealed that all Mia+ blood samples gave a positive with GP. Hut, GP. HF, GP. Mur, GP. Hop, and GP. Bun. Results of the gel card method and PCR-SSP were concordant. Hence, using PAD-Mia typing in blood donors would be helpful for creating a phenotype database of blood donors for reducing alloimmunization risks.

Incidence of acute haemolysis in cats receiving canine packed red blood cells (xenotransfusions).

The aim of this study was to report the incidence of transfusion reactions in cats, including acute haemolysis (AH), occurring within 24 h of receiving a xenotransfusion. An additional aim was to determine whether cases with AH could be classified as having an acute haemolytic transfusion reaction (AHTR) as per the definition provided by the Association of Veterinary Haematology and Transfusion Medicine's Transfusion Reaction Small Animal Consensus Statement. Medical records of cats that received canine packed red blood cells (PRBCs) between July 2018 and September 2020 at a veterinary hospital were reviewed. The incidence of AH, AHTRs, febrile non-haemolytic transfusion reactions (FNHTRs), transfusion-associated circulatory overload and septic transfusion reactions were recorded. The medical records of 53 cats were retrospectively evaluated. Twenty-three (43%) cats had transfusion reactions. Thirteen (25%) cats had AH; however, only four (8%) met the definition of an AHTR. Ten (19%) cats were determined to have FNHTRs. Survival to discharge of cats affected by AH was 50% (25% for cases that met the definition of an AHTR). Survival to discharge of cats not suffering from AHTR was 40%. This report indicates that a higher proportion of cats undergo AH (25%) when administered canine PRBCs than previously reported, although many could not be classed as having an AHTR due to an apparently adequate packed cell volume rise. Challenges with sourcing feline blood in emergency situations occasionally necessitates the use of xenotransfusion in transfusion medicine. Clinicians should be aware that haemolysis after xenotransfusion can occur within 24 h and that a repeat feline transfusion may be required sooner than anticipated in some cases.

A CLINICOHAEMATOLOGICAL PROFILE OF ADVERSE TRANSFUSION REACTIONS AND ITS ASSOCIATION WITH BLOOD COMPONENTS

Different blood components are associated with various types of adverse transfusion reactions and are linked to several factors including the number, rate and volume of transfusions. The given study was conducted to study the relationship between various transfusion reactions and its causative factors. This study was a prospective study of eighteen months on all patients who were recipient of a blood transfusion and blood components including various adverse reactions and events related to transfusion. These were correlated with tests for compatibility including general blood picture ,tests for haemolysis ,hematuria and haemoglobinuria, Coombs Test (Direct and Indirect), culture along with relevant clinical details of the patient. Out of a total of 31451 units of blood issued, 47 adverse transfusion reactions were noted with a maximum number in the age group of &gt; 18 years (87.3%) with M: F being 1.6: 1 .0.24% of adverse transfusion reactions were by Packed red blood cell (PRBCs) transfusion and mostly were immediate transfusion with a mean volume of 100 ml and mean time of 20 minutes. Febrile Non Hemolytic Transfusion Reaction (FNHTR) was the commonest Adverse Transfusion Reaction (ATR)(0.128%) with 2 cases positive for Direct Coombs Test. A thorough serological and immunological examination and the addition of methods like buffy coat reduction and leucocyte filtration help in reducing the incidences of hemolytic transfusion reactions and transmitted infections and establishing a hemovigilance system help in the attainment of the goal of safe transfusion.

The KANNO blood group system.

The KANNO blood group system (International Society of Blood Transfusion [ISBT] 037) includes one high-prevalence antigen, KANNO1, across ethnic groups. Sporadic KANNO1- cases among East and South Asians are theoretically estimated by the DNA database library. Anti-KANNO1 has been found most often among Japanese women with current or prior pregnancy. Thus far, there are no reported cases of hemolytic transfusion reaction or hemolytic disease of the fetus and newborn due to anti-KANNO1.

An Audit on Transfusion error in 16 years of blood transfusion practice at a Teaching Hospital in North Eastern Malaysia

Clinical demand for blood transfusion is endless, and patients are exposed to the risk of transfusion error at any point along the transfusion chain which lead to incorrect blood component transfused (IBCT) if the standard transfusion practices have not complied. This study aimed to determine the prevalence, sources, and causes of error among IBCT in Hospital USM. This retrospective study involved all packed red cell (PC) transfusion and reported IBCT in Transfusion Medicine Units, Hospital USM from January 2005 to December 2020. The recipient and transfusion data of IBCT were collected from the medical record and laboratory information system (MyTransfusi). A total of 193 697 PC transfusions were documented, and 14 IBCT were reported within 16 years of transfusion services. The incidence of IBCT was 1 in 13 836 of PC transfusion. Most of the IBCT contributed by ward error (64.3%). The major cause of error was patient miss identification (85.7%) either in patient sampling, blood component issuing and administration. Most ABO incompatibility IBCT (3 out of 5) end up with severe morbidity or mortality related to an acute haemolytic transfusion reaction. Most of the errors occurred in the wards. Patient misidentification is a major cause of IBCT, and it is preventable. Thus, preventive measures should emphasize on positive patient identification at every step of transfusion chain.

Blood Groups ABO and Rh System Among Paternity and Kinship Cases of Iraqi Medical Legal Directorate

ABO and Rh are the most important blood group systems with various distributions reported for different populations. Traditional ABO blood group and Rh serology is based on the immunoreactivity of antisera with the carbohydrate A, B and H antigens on Red Blood Cells (RBC). Due to its medical importance in relation to different diseases, pursuing a line of investigation on the ABO and Rh blood group systems has been of significance for years. It is well known that these blood group systems are of great importance in blood transfusion and organ transplantation. Furthermore, the susceptibility to several diseases has been associated with the ABO phenotype, but such correlation remains controversial. Progress in the molecular biology of the ABO system has recognized the molecular basis of the red blood cell antigens and has provided a genetic model for ABO polymorphism at the molecular level. The ABH antigens are not primary gene product, but they are the enzymatic reaction product of enzymes called glycosyltransferases. After the ABO system, the Rh (Rhesus) blood group system is regarded as the second most important blood group system, as some of the severe hemolytic transfusion reactions and most hemolytic disease of the fetus and new born (HDFN) cases are associated with antibodies to the Rh group antigens. Objectives: To determine ABO blood group and Rh factor phenotype antigens frequency, distribution, and document among paternity cases of Iraqi Medical Legal Directorate / Clinical Forensic Department / paternity and kinship division. Materials and Methods: The material and methods were used ABO and Rh kits for detection phenotype antigens of this blood types, the principle of test is one step immunological reaction. Total samples (1997) were referred to medical Legal Directorate (MLD). Out of the total participants there were 1815 (98.4%) of samples complete information for inclusion criteria. the sample were used for estimation of phenotypic distribution of ABO, Rh. ABO blood group serology was performed at MLD, Paternity and Kinship Division using commercially available monoclonal Anti-A, Anti-B, reagents according to the national blood bank standard operating procedures. The Method principle is based on antigen antibody reaction (agglutination) some tests were confirmed under microscope examination to see weak reaction. Results: The most common blood group was O (52.3%) and the least common was AB (3.18%).97.7% of the blood participants were Rh Positive and the rest were Rh Negative. Most participants were young adults, representing the age group of 19 – 29. Most participants were male (88.1%). Conclusion: Blood group O and Rh+ factor was dominant in both sexes, Up-to-date knowledge of the distribution of blood types in a local setting is critical to the functioning of any national health service. To date, there has been a lack of data in Iraqi population.

Clinical consequences of a 30-day interval between antibody identifications.

While studies have shown that antibody detection may be delayed if an antibody identification (ABID) is not performed every 3 days, little data exist on the potential major risk of an acute hemolytic transfusion reaction (aHTR). At our institution, if no change in the screen, or a positive crossmatch, ABIDs are performed every 30 days. Between January 1, 2015 and May 31, 2019, all new antibodies detected within 28 days of a prior transfusion were identified. Testing results and patient charts were reviewed for evidence of hemolysis. The $211 patient charge was used to determine the cost for ABIDs performed during the studied time period. For 36 patients, a new clinically significant alloantibody was detected within 28 days of an antigen-positive transfusion. Only one of these patients had a history of prior alloimmunization and put at possible risk due to the ABID policy. For this patient, while there was less than the expected increment to an antigen-positive unit, there was no clinical or laboratory evidence of an aHTR. During this same time, 6095 ABIDs were performed, at a cost of approximately $1.29 million, and 72,665 red cell transfusions occurred. With an ABID every 30 days, only one patient, over 4.5 years, was put at potential risk for hemolysis from one transfusion (0.001% of the total units transfused during the time period). While antibody detection may be delayed, performing ABIDs every 30 days saves money and medical laboratory scientist time and should be balanced against potential patient harm.

The complexities of transfusion reactions: Coexistence of a delayed haemolytic transfusion reaction and post-transfusion purpura.

Immune-mediated acute or delayed transfusion reactions occur when there is immunological incompatibility between transfused blood products and recipient's antibodies. Acute haemolytic transfusion reactions occur within 24 h and are delayed after 24 h up to 10 days following transfusion, whereas post-transfusion purpura (PTP) typically occurs 7-10 days post-transfusion. We present a case of a previously transfused and recently post-partum female who developed both delayed haemolytic transfusion reaction (DHTR) and PTP. A 42-year-old woman, G2P1, with non-alcoholic liver disease, portal hypertension and previous transfusion history with allogeneic anti-E, developed a severe DHTR and PTP following a complicated post-partum course and multiple transfusions. The antenatal and initial post-partum pre-transfusion antibody screens were negative. Subsequently five red cell antibodies, including anti-c, anti-Fya, anti-Jkb and anti-S and the reappearance of anti-E were, however, identified during follow-up investigations along with the anti-platelet antibody HPA-3a and human leukocyte antigen class I antibodies. Anti-E, anti-Jkb and anti-S were eluted from the circulating red blood cells. To our knowledge, there have been only two other case reports of DHTR and PTP occurring in the same patient.

Severe acute haemolytic transfusion reaction secondary to a plasma incompatible group B platelet transfusion.

To report a rare case of acute hemolytic transfusion reaction (AHTR) following an ABO plasma incompatible group B platelet transfusion. AHTR is an uncommon, but potentially fatal event. Most reported cases of platelet transfusions associated with AHTR involve group O donors. A 34-year-old man, recipient of a group AB haploidentical haematopoietic stem cell transplantation (HSCT), had received re-induction chemotherapy for leukaemia relapse. A group B whole blood-derived buffy coat platelet pool was transfused. He developed rigours/fever, profound hemolytic anaemia, and hemodynamic instability. Serological investigations revealed AHTR from passive transfer of high titre anti-A (256 for IgM and 8192 for IgG). This case highlights the potential risks associated with ABO-mismatched transfusions, and the complexity associated with transfusing HSCT recipients and red cell transfusion recipients with dual populations of circulating red cells. The literature on minor ABO plasma incompatible transfusions, challenges in establishing local policies to limit the risks of AHTR and risk mitigation strategies are discussed. Clinicians must maintain a high level of suspicion for AHTR after ABO plasma incompatible platelet transfusions. Patients must be aware of the risks of AHTR, and early recognition and diagnosis of this complication may be lifesaving.

Impact of Transfusion Program during Pregnancy on the Obstetrical Outcomes in Sickle Cell Disease Women

Introduction: Pregnancy in sickle cell womenis associated with adverse maternal outcomes. Studies evaluating the effects of the transfusion program (TP) during pregnancy are contradictory. The objective of this retrospective study was to evaluate the effect of the transfusion program on maternal and neonatal outcomes in Sickle cell disease (SCD) . Since the publications highlighting the frequency of delayed hemolysis transfusion reaction (DHTR) in SCD patients and particularly in pregnant women, transfusion(TF) indications have changed in the management of pregnancies. Transfusion indications have been limited since 2015 in view of the risks of alloimmunization and DHTR, associated with the lack of evidence of obstetrical benefit, in SCD pregnancies (10). Our objective was to evaluate the impact of the transfusion program during pregnancy on obstetric and neonatal outcomes with a propensity score to account for potential biases. Method: This is a retrospective cohort study based on analysis of electronic and paper medical records including all pregnancies in women with SCD (Hb SS, SC, S beta-thalassemia phenotypes) who received prenatal care delivered in a French tertiary care academic center (CHI-Créteil) and in Henri Mondor SCD referral center between January 2004 and December 2017. The DHTR risk score was defined for all patients. Confounding factors considered in a propensity score were delivery period, SCD genotype, history of acute chest syndrome (ACS), and delayed hemolytic transfusion reaction (DHTR) risk score. Results: We analyzed 246 pregnancies in 173 patients. Twenty-two pregnancies with a history of DHTR were analyzed separately. We found a higher frequency of TP before 2013 (119/148 [80.4%] vs 38/76 [50%], p<0.001). Patients with a history of ACS and a low DHTR risk score were significantly more represented in the transfusion program group. There was no difference between the two groups in the frequency of preeclampsia, eclampsia, Hellp syndrome, term of delivery , births <37 weeks, birth weight, and cesarean section. Punctual transfusions were more frequent in the group without TF program. Rates of preterm birth before 34 weeks, vaso-occlusives crisis(VOC) and ACS during pregnancy were significantly more frequent in the group without a transfusion program. There were 4 inaugural DHTRs in each of the 2 groups and 4 deaths in the TF Program group; this difference was not significant. Multivariate analysis weighted by propensity score showed that TF program was associated only with a significant reduction in the risk of preterm delivery before 34 weeks (OR= 0.05 95% CI [0.01-0.31], p = 0.001). Of the 22 pregnancies with a history of DHTR, 4 were complicated by a new DHTR event after emergency transfusion. The rates of delivery before 34 and 37 Weeks of gestation, neonatal death, frequency of ACS, hospitalization during pregnancy and in intensive care unit, and composite adverse obstetric outcome were significantly different between the group with a history of DHTR and all patients without known DHTR, confirming the potential seriousness of these patients. Conclusion: This study shows a trend toward reduced routine use of the transfusion program during pregnancy. There was no difference between the two groups( TP and without TP) in the frequency of pre-eclampsia, eclampsia, Hellp syndrome, term of delivery and births <37 weeks, birth weight and caesarean section. Propensity score-weighted analysis reveals an independent protective effect of the transfusion program on prematurity before 34 weeks as well as composite obstetric criteria (birth <34 weeks and/or preeclampsia and/or SGA and/or abruption and/or IUFD and/or maternal death and/or neonatal death). Although the benefit/risk balance of the transfusion program should be considered on a case-by-case basis with the DHTR risk score in early pregnancy. In patients with low transfusion risk, transfusions may be recommended upon discontinuation of HU or in case of VOC complications. Prospective studies are still needed on large homogeneous patient populations and the evaluation of alternative treatments to transfusion such as hydroxycarbamide seems important.

Optimizing Use of Automated Isovolemic Hemodilution Red-Cell Exchange in a Patient Cohort with Sickle Cell Disease: A Quality Improvement Intervention

Background: Red-cell exchange (RCE) is a mainstay of treatment for both acute and chronic complications of sickle cell disease (SCD). It is a resource-intensive intervention requiring transfusion of large volumes of antigen-matched red blood cells (RBC). Identifying suitable RBC units can be challenging due to variability in blood group phenotypes between patients with SCD and the donor population. This often results in use of O-negative units, which are a scarce resource. Efforts to reduce the volume of units transfused, while maintaining therapeutic efficacy is an important clinical need. Isovolemic hemodilution (IHD) prior to RCE reduces the required volume of RBCs. The aim of this project is to evaluate the effect of a change to IHD-RCE on RBC utilization in patients with SCD receiving standard RCE. Methods: All adult SCD patients receiving standard RCE at the Ottawa Hospital were identified. To safely attain a meaningful reduction in transfused RBCs, RCE treatment parameters were individualized for each patient (Table 1). Patient hematocrit was not allowed to decrease below 20% during the depletion phase, and IHD-RCE would be performed only if an estimated reduction in RBC volume of at least 200 mL was expected. Pregnant patients were excluded. Change in RCE protocol to IHD-RCE took place in January 2022. Transfusion and clinical data were obtained from databases at the Ottawa Hospital in the six months preceding and succeeding the change in RCE protocols to allow for a pre- and post-intervention comparison. Results: Thirty-four adults receiving regular RCE for SCD were identified. Twenty-two patients met criteria for a protocol change to IHD-RCE. The mean age of the IHD-RCE cohort was 31 years (SD 9.5). Males comprised 72.7% of this cohort, with the most frequent genotype of hemoglobin SS (68.2%). Over the one-year study period, 1963 RBC units were transfused: 1035 RBC units in the pre-intervention period, and 928 units in the post-intervention period, representing a reduction of 107 RBC units. 1958 (99.7%) of the RBC units transfused were transfused in the setting of RCE, with few (5 units; 0.03%) administered as simple RBC transfusions. Table 2 outlines patient outcomes during the study period. The mean number of RBC units transfused per patient in the pre- and post-intervention periods were 47 and 42.4 units, respectively. The mean number of RBC units per RCE session per patient was significantly reduced from 8.7 units in the pre-intervention period to 7.8 units in the IHD-RCE post-intervention period (mean difference: -0.9, 95% CI: -1.2 to -0.5). A total of 236 RCE sessions occurred during the study period. No difference in RCE session frequency was observed with a change to IHD-RCE during the six-month study period, nor time between RCE sessions. Therapeutic efficacy in attaining target hemoglobin S levels was not affected by the change to IHD-RCE. No adverse patient safety signals were observed during the IHD-RCE sessions to date. Conclusions: This study demonstrates that IHD-RCE, compared to standard RCE, substantially reduces RBC utilization. A total of 107 RBC units were conserved in our patient cohort of 22 chronic RCE patients directly from the transition to IHD-RCE from standard RCE. Based on local RBC per unit costs, this corresponds to an annualized saving of $95,444 CAD. With pressure on blood banks to provide appropriately matched units, and risks of alloimmunization and delayed hemolytic transfusion reactions amongst chronically transfused SCD patients, increased uptake of IHD-RCE should be considered for SCD patients on chronic RCE. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Avoiding Daratumumab Interference with Blood Typing

Background Daratumumab is an IgG monoclonal antibody that binds CD38 on hematopoietic cells and induces apoptosis. It is FDA approved for upfront treatment of systemic light chain amyloidosis as well as treatment of frontline and relapsed/refractory multiple myeloma. Daratumumab, similar to other CD38 monoclonal antibodies, interferes with blood compatibility testing by causing panagglunination on the Indirect Antiglobulin Test (IAT) leading to false positive results and delays in blood availability for transfusion. This panagglutination can persist up to 6 months after the last Daratumumab infusion. Additionally, attempts to overcome this may mask the presence of a clinically significant antibody resulting in acute or delayed hemolytic transfusion reactions. Several laboratory techniques like RBC genotyping, phenotyping, and the use of Dithiothretol (DTT) treatment of serum are used to overcome this laboratory abnormality. These are either technically time consuming or not widely available in all healthcare institutions. DTT, though readily available, requires prior notification of the blood bank when a patient who is being treated with Daratumumab needs a transfusion. This labor intensive and time consuming process may result in delays in patient care adverse outcomes. By far, the most cost effective way is to obtain blood type and antibody screen (IAT) prior to the initial Daratumumab administration. However, this requires institutional strategy (policy, procedure and pathway) for all potential patients starting anti CD38 monoclonal antibodies in general and daratumumab in particular, to allow timely typing and screening of blood in preparation for future transfusion needs. This quality improvement project was instituted to obtain a type and screen (T&S) prior to patients starting Daratumumab in order to champion high value healthcare which balances clinical benefit with costs and harms with the ultimate goal of improving patient outcomes. Methods and Results We retrospectively identified 32 patients who received their first Daratumumab infusion or subcutaneous injection from 11/1/2017 to 5/31/2020 at Community Medical Centers and Community Cancer Institute in Clovis, California and Fresno, California. 13 patients did not have a T&S done within 30 days prior to initiation of Daratumumab, which translates to 40.6%. We conducted manual chart of all patients prior to the intervention and found 6 patients without prior T&S who required transfusions after starting Daratumumab. Each transfusion was regarded as an event regardless of the units of blood received. We calculated the time from T&S order to receipt of transfusion. In total, there were 15 events which amounts to 1,5990 cumulative minute, with the average time to transfusion (TTT) being 1066 minutes. There were also 6 patients with T&S performed prior to Daratumumab initiation who had a total of 22 transfusion events that took 20417 minutes. The average TTT for this group is 928 minutes. The difference in average TTT between patients who had T&S and those that did not have T&S is 138 minutes, which can be clinically significant. We implemented a T&S as part of "Day 0" in our chemotherapy orders in December 2020. 17 patients received their first Daratumumab from January 2021 to January 2022. 15 patients (88%) had T&S performed and 2 patients did not as they were patients from out of network providers. Conclusion We are continuing to gather additional data to see if this improvement results in a decrease in average TTT post implementation. This is quality improvement project represents a major step in reducing delays in blood compatibility testing due to Daratumumab. There are no significant changes in resource utilization since patients who need transfusions will require a T&S to be done regardless. Ensuring that a T&S is performed antecedent to the first Daratumumab treatment will reduce delays in obtaining matched blood products for our myeloma patients. This supports timely transfusions to lower adverse outcomes associated with anemia due to chemotherapy and multiple myeloma.

A US-Wide Red Blood Cell Alloantibody Exchange Can Decrease Mortality and Produce Cost Savings in the Care of Alloimmunized Patients with Sickle Cell Disease

Introduction: Red blood cell (RBC) alloimmunization occurs after exposure to non-self RBC antigens through transfusion or pregnancy. Alloimmunization rates and consequently delayed hemolytic transfusion reaction (DHTR) mortality in patients with sickle cell disease (SCD) is particularly high. Interest in a blood bank information system vendor-based alloantibody exchange in the United States (US) is growing, though cost concerns exist. To investigate the impact of an exchange that enables alloantibody data-sharing across hospitals, we conducted the first disease simulation of allo-immunized patients with SCD to project lifetime cumulative DHTR-specific mortality without an alloantibody exchange (status quo) versus with a US-wide alloantibody exchange. We then additionally performed a cost-effectiveness analysis to identify whether investing in an alloantibody exchange would be cost-effective, cost saving or neither. Methods: We built a Markov simulation of alloimmunized patients with SCD in the US. Transition probabilities for DHTR incidence and DHTR-specific mortality were informed from the largest prospective (n=311) and retrospective (n=220) studies of DHTR incidence in people living with SCD. Age-, gender- and disease-specific background mortality probabilities were employed. Cumulative probability of DHTR was modeled from age 5, with a lifetime horizon. Costs were assessed from the health system perspective and effectiveness was calculated in quality-adjusted life-years (QALY). QALYs were informed by published lifetime simulation of patients living with SCD and matched controls. These were originally derived from a polynomial fit linking Euroqual-5 Dimensions to the visual analog scale for pain in patients with SCD in several studies. Cost-effectiveness was quantified using an incremental cost-effectiveness ratio (ICER), or net monetary benefits (NMB) if the intervention was found to be cost saving, either way incorporating a cost-effectiveness willingness-to-pay threshold of $100,000/QALY, as recommended practice. We assumed a lifetime operating cost of $10 million for an alloantibody exchange, that no patient with diagnosed DHTR has more than one DHTR recurrence, that an exchange would not be able to prevent all DHTRs (as up to 30% are not associated with a new detectable antibody in SCD), and utilized prior estimates for US allo-immunized population prevalence range of 20-44% for people living with SCD. We validated our estimate for DHTR reduction with that of the 10-year experience in the national Dutch Transfusion Register of Irregular Antibodies and Cross-match Problems (TRIX). We then conducted deterministic and probabilistic sensitivity analyses, varying all parameter estimates +/-20% and capturing uncertainty in all parameters simultaneously over 10,000 Monte Carlo simulations. Results: Base-case lifetime simulation comparing the strategies of implementing an alloantibody exchange versus not yields a decrease in cumulative lifetime DHTR-specific mortality (2.4% vs 5.7%, respectively; Figure 1). The absolute peak probability decrease of having a history of incident DHTR and being alive occurs at age 41 (10.6% vs 27.0%; Figure 1). The strategy of alloantibody exchange implementation accrues 22.08 per-person lifetime discounted QALYs [95% credible interval 22.03-22.12] versus 21.72 without [95% CI 21.61-21.82], corresponding to a per-person QALY increase of 0.357 with exchange implementation. The lifetime population benefit for an alloimmunized population living with SCD in the United States is up to 15,710 QALYs gained. Total lifetime costs accrue $1.0 billion with exchange as compared to $2.5 billion without. This yields population-level cost savings of $1.5 billion USD ($34,091 saved per alloimmunized patient registered in the exchange), with an accrued incremental NMB of $3 billion. In probabilistic sensitivity analysis the former is favored in 100% of 10,000 Monte Carlo simulations. Conclusion: By reducing DHTR-specific mortality, an alloantibody exchange is predicted to be a life- and cost-saving investment for alloimmunized people living with SCD. Although this analysis was limited to SCD, the impact of an alloantibody exchange would also bring benefit to patients who are alloimmunized in the context of diagnoses and states beyond SCD, such as myelodysplastic syndrome, thalassemia, autoimmune conditions, and pregnancy. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal