Anti-D immunization after D positive platelet transfusions in D negative recipients: A systematic review and meta-analysis.

BACKGROUND: Anti-D can be formed after D-incompatible platelet transfusions due to contaminating D+ red blood cells. These antibodies are of particular importance in women of childbearing potential, because anti-D is most often involved in severe cases of hemolytic disease of the fetus and newborn. This systematic review determined the frequency of anti-D after D+ platelet transfusions and risk factors for D alloimmunization. STUDY DESIGN AND METHODS: Relevant literature was searched using PubMed, Embase and Web of Science until December 2022. Overall anti-D frequency and risk factors were estimated using a random effects meta-analysis. RESULTS: In 22 studies, a total of 3028 D- patients received a mean of six D+ platelet transfusions. After a mean follow-up of seven months 106 of 2808 eligible patients formed anti-D. The pooled anti-D frequency was 3.3% (95% CI 2.0-5.0%; I2 71%). After including only patients with an undoubtable follow-up of at least 4 weeks, 29 of 1497 patients formed anti-D with a pooled primary anti-D rate of 1.9% (95% CI 0.9-3.2%, I2 44%). Women and patients receiving whole blood derived platelets had two and five times higher anti-D rates compared with men and patients receiving apheresis derived platelets, respectively. DISCUSSION: Anti-D immunization is low after D incompatible platelet transfusions and dependent on recipients' sex and platelet source. We propose anti-D prophylaxis in girls and women, capable of becoming pregnant in the future, that received D+ platelets, regardless of platelet source, to reduce the risk of anti-D induced hemolytic disease of the fetus and newborn.

Extensive red blood cell matching considering patient alloimmunization risk.

BACKGROUND AND OBJECTIVES: Red blood cell (RBC) transfusions pose a risk of alloantibody development in patients. For patients with increased alloimmunization risk, extended preventive matching is advised, encompassing not only the ABO-D blood groups but also the most clinically relevant minor antigens: C, c, E, e, K, Fya, Fyb, Jka, Jkb, S and s. This study incorporates patient-specific data and the clinical consequences of mismatching into the allocation process. MATERIALS AND METHODS: We have redefined the MINimize Relative Alloimmunization Risks (MINRAR) model to include patient group preferences in selecting RBC units from a finite supply. A linear optimization approach was employed, considering both antigen immunogenicity and the clinical impact of mismatches for specific patient groups. We also explore the advantages of informing the blood bank about scheduled transfusions, allowing for a more strategic blood distribution. The model is evaluated using historical data from two Dutch hospitals, measuring shortages and minor antigen mismatches. RESULTS: The updated model, emphasizing patient group-specific considerations, achieves a similar number of mismatches as the original, yet shifts mismatches among patient groups and antigens, reducing expected alloimmunization consequences. Simultaneous matching for multiple hospitals at the distribution centre level, considering scheduled demands, led to a 30% decrease in mismatches and a 92% reduction in shortages. CONCLUSION: The reduction of expected alloimmunization consequences by incorporating patient group preferences demonstrates our strategy's effectiveness for patient health. Substantial reductions in mismatches and shortages with multi-hospital collaboration highlights the importance of sharing information in the blood supply chain.

Implementation of a blood bank generated tube for second blood group determination: Challenges, yield, and cost.

BACKGROUND: The second blood group determination or group check sample is a process of verifying the ABO group with a second blood sample prior to transfusion. It has been used to detect errors related to wrong blood in tube (WBIT) events and reduce the risk of ABO-incompatible transfusions. To prevent the clinical team from collecting the group check sample at the same time as the first sample, a tan top tube only available from the blood bank was introduced for second blood group determinations if drawn within 24 h of the first group and screen. STUDY DESIGN AND METHODS: This is a retrospective study analyzing data from 2005 to 2020 before and after the implementation of the blood bank supplied tan top tube for group check. The number of WBIT events, transfusion delays, and health care costs were determined. RESULTS: The number of WBIT events remained unchanged throughout the time period. No delays in transfusion or procedure were reported due to the tan top tube group check. There was no increase in group O transfusions over time. In comparison to using an ethylenediaminetetraacetic acid (EDTA) tube, the tan top tube was estimated to add an extra yearly cost of $790.79 Canadian dollars. CONCLUSION: Second blood group determination using the blood bank supplied tan top tube did not increase the number of WBIT events detected but ensured an independent sample draw. A minimal incremental cost of implementing the tan top tube was noted with no delay in transfusions or procedures.

Sample collection for pre-transfusion crossmatching: Benefits of using an electronic identification system.

BACKGROUND: Transfusion of ABO blood group-mismatched blood or administration to the wrong recipient may result in fatal adverse events. To prevent these types of errors, various strategies have been employed. Recently, we developed a novel sample collection workflow for the pre-transfusion crossmatching test and patient recognition. This study aimed to analyse the usage of the new workflow and improvements in outcomes. METHODS: We analysed the number of crossmatching and wrong-patient errors among the blood transfusion cases during 3 years of data collection (from August 2018 to July 2021). From May 2021 to July 2021, the new workflow was implemented. Outcomes were calculated according to the department type, patient age and processing time. The sample processing time was defined as the time from placing the order to lab arrival. RESULTS: The new workflow utilisation increased from 50.7% to 80.3% and wrong-patient errors decreased annually. The new workflow was used for more adults (3001/3680 samples, 81.5%) than paediatric cases (345/522 samples, 65.5%; p < 0.001) and in general wards than in the emergency room or intensive care unit. The sample processing time differed according to ward type and timing of the request (day: 28.80, 2.43-3889.43 min, night: 3.36, 2.72-1671.47 min; p < 0.001). CONCLUSION: Wrong-patient errors were reduced without increasing sample-processing time after introducing the new workflow which included using an electronic identification system. The time needed for the blood processing differed according to the ward type, patient age, and timing of the request. Patient safety can be promoted by managing these factors and using an electronic identification system.

Noninfectious transfusion-associated adverse events and their mitigation strategies.

Blood transfusions are life-saving therapies; however, they can result in adverse events that can be infectious or, more commonly, noninfectious. The most common noninfectious reactions include febrile nonhemolytic transfusion reactions, allergic transfusion reactions, transfusion-associated circulatory overload, transfusion-related acute lung injury, and acute and delayed hemolytic transfusion reactions. These reactions can be asymptomatic, mild, or potentially fatal. There are several new methodologies to diagnose, treat, and prevent these reactions. Hemovigilance systems for monitoring transfusion events have been developed and demonstrated decreases in some adverse events, such as hemolytic transfusion reactions. Now vein-to-vein databases are being created to study the interactions of the donor, product, and patient factors in the role of adverse outcomes. This article reviews the definition, pathophysiology, management, and mitigation strategies, including the role of the donor, product, and patient, of the most common noninfectious transfusion-associated adverse events. Prevention strategies, such as leukoreduction, plasma reduction, additive solutions, and patient blood management programs, are actively being used to enhance transfusion safety. Understanding the incidence, pathophysiology, and current management strategies will help to create innovative products and continually hone in on best transfusion practices that suit individualized patient needs.

How to verify patient identity and blood product compatibility using an electronic bedside transfusion system.

Transfusion of an incorrect blood component is an important avoidable serious hazard of transfusion resulting from process errors. Our group and others have taken advantage of new technology and developed electronic transfusion systems for safe transfusion practice in a previous studies. They allow the clinical staff to correctly identify the patient and the blood product at the bedside, ensuring the right blood product is given to the right patient. This video is to demonstrate the process and not to promote any specific product. It is a follow up our previous video clip on electronic remote blood issue in a previous study. The process for correct patient identification originates from the wristband, which contains the patient identification details in a 2D barcode and is printed from the electronic patient record system. These details are associated with the blood sample through using a portable printer to produce a label for the sample tube. The patient details are scanned into the blood bank laboratory information system (LIS) and are then printed on a compatibility label by the LIS, which also contains a 2-dimensional barcode, and is then attached to the blood product. Following an initial visual check of these details by the clinical staff, the electronic bedside system requires that both the patient wristband barcode and the blood product compatibility barcode are scanned. This will electronically verify at the patient's bedside that the right unit is to be given to the right patient. This is the final step in ensuring end-to-end electronic control and safe transfusion practice.

Challenge to ABO blood type barrier in living donor liver transplantation.

ABO incompatible living donor liver transplantation has the potential to expand the donor pool for patients with end stage liver diseases on the expense of challenges to overcome immunological barriers across blood type. There is a profound impact of age on incidence and severity of antibody mediated rejection (AMR). Even children older than 1 year have chances of AMR; children aged 8 years or older have risks of hepatic necrosis similar to adult liver recipients. The mechanism of AMR is based on circulatory disturbances secondary to inflammation and injury of the vascular endothelium caused by an antibody-antigen-complement reaction. The strategy to overcome ABO blood type barrier is based on both pre-transplant desensitization and adequate treatment of this phenomenon. Nowadays, rituximab is the standard means of desensitization but unfortunately an insufficient aid to treat AMR. Because of low incidence (less than 5% in the rituximab era), in practice of AMR only some case reports about the treatment of clinical AMR are available in the literature. Initial experiences revealed that the proteasome inhibitor, bortezomib might be a promising treatment based on its capacity to deplete plasma cell agents. Although ABO blood type barrier has been counteracted in 95% of patients by applying "rituximab-desensitization", many issues, such as prediction of high-risk patients of infection and AMR and secure treatment strategies for evoked AMR, remain to be resolved.

Management of patients with rare blood groups in maternity.

We report on our experiences since 2010 with pregnant women with rare blood types. The lack of compatible blood is a challenge for the anaesthetist whose priority is to prevent and treat anaemia in late pregnancy in order to avoid immunisation after transfusion of incompatible blood. In our hospital, the blood type is checked during the first obstetric consult, which is variable, starting from the fourth month of pregnancy. Rare blood types are most often diagnosed in an advanced stage of pregnancy (30 weeks of gestation: WG) due to the late inscription for obstetrics consult, resulting in even later anaesthetic visit. In our 13 patients, the most common blood systems are Duffy, MNS, and RH. 61.5% of the patients have associated antibodies (anti-MNS5). The majority of patients received iron with significant increase of ferritin (17.24 ± 12.95 µg/L versus 262.2 ± 404.4 µg/L, p = .033). Six of the patients had 2-3 injections of EPO between 29 - 36 + 1 WG. There were no transfers for paediatric management of haemolytic disease in the newborn following the birth. Overall, this treatment of patients with a rare blood group has also changed our practices for the follow-up of other pregnant women, and ferritin is more regularly prescribed.Impact statementWhat is already known on this subject? For rare blood groups, the frequency in the general population is less than 1/4000. The most common antibodies at risk of haemolytic disease and 'hydrops fetalis' are anti-D, anti-E, anti-C, and anti-K. The survey of pregnant women with a rare blood type takes into account the maternal risk of 'transfusion deadlock' and haemolytic disease of the newborn.What do the results of this study add? Rare blood types are most often diagnosed in an advanced stage of pregnancy (30 WG) due to the late inscription for obstetrics consults at Maternity. The most common blood systems are Duffy, MNS, RH, and 61.5% of the patients have associated antibodies (anti-MNS5). The most efficient treatment of prenatal anaemia was iron perfusions who allowed significant increase of ferritin and a maternal haemoglobin concentration of 12.1±1.46 g/dL in the ninth month of pregnancy.What are the implications of these findings for clinical practice and/or further research? A pregnant woman with a rare blood group is a situation that requires a technical platform specialised in haemorrhagic risk and a multidisciplinary team, including a blood bank as well as anaesthetic and obstetrical teams, with excellent interdisciplinary coordination.

Multiplex blood group typing by cellular surface plasmon resonance imaging.

BACKGROUND: Blood-group typing of donors and patients is essential to avoid incompatible transfusions. Transfusion of incompatible RBCs may result in alloimmunization complicating future transfusions or in the presence of antibodies in adverse reactions. With more than 300 blood group antigens identified, it is difficult to provide fully compatible blood. Currently, standard practice is to match for the most immunogenic antigens. While the current agglutination-based RBC-typing methods are reliable for testing a selected number of antigens, they are not easily adaptable for high-throughput multiplex blood typing beyond the current standard. STUDY DESIGN AND METHODS: Surface plasmon resonance (SPR) is a label-free method to follow molecular-and, very recently, also cellular-interactions in real time. Demonstration of binding of RBCs to blood group antigen-specific antibodies by SPR has already been achieved. Here, we demonstrate the generation of an SPR array equipped with clinically relevant blood group antibodies (A, B, and Rh blood groups). To validate this method, we blindly compared typing of 946 blood donors with results of current diagnostic agglutination-based methods. RESULTS: RBC typing was achieved by monitoring RBC binding to blood group-specific antibodies on the sensor simultaneously within 5 minutes per sample. Regeneration of the chip was robust, allowing for typing of at least 100 samples. The typing results gave a 100% match with classical serology with all antibodies tested besides anti-E/e monoclonals, which gave inconsistent results due to low antibody specificity. CONCLUSION: This study demonstrates that SPR-based RBC typing for multiple antigens can be realized simultaneously with high-quality antibodies, enabling reduced hands-on time and possibly improving cost efficiency.

Evaluating safety and cost-effectiveness of platelets stored in additive solution (PAS-F) as a hemolysis risk mitigation strategy.

BACKGROUND: Platelet inventory constraints can result in minor ABO incompatibility and possible hemolysis. The aims of this study were to determine the reduction of isoagglutinin in titers of platelets stored in additive solution (PAS) and compare its safety, efficiency, and cost-effectiveness with full-volume and plasma-reduced platelets. STUDY DESIGN AND METHODS: Isoagglutinin titers were performed in paired whole blood donor samples and apheresis platelets collected in PAS (PAS-PLT) aliquot samples by the tube method. RESULTS: A total of 149 pairs of donor/platelet samples were tested: 75 group O, 59 group A, and 15 group B. For group O donor samples, the median anti-A IgG and IgM were 64 and 16, respectively, and the median anti-B IgG and IgM were 64 and 16, respectively. For group O PAS-PLT samples the mean anti-A IgG and IgM, and anti-B IgG and IgM were 32 and 8, and 16 and 8, respectively. For group A donor samples, the mean anti-B IgG and IgM was 8 in both cases; and both titers decreased to 2 in PAS-PLT. For group B donor samples, mean anti-A IgG and IgM was 16 in both cases; and both titers decreased to 4 in PAS-PLT. PAS-PLT demonstrated a net reduction in cost and improved efficiency when compared to plasma reduction. The use of PAS-PLT resulted in a 40% reduction of allergic transfusion reactions. CONCLUSION: The use of PAS decreases plasma isoagglutinin titers, transfusion reactions, and is cost-effective when compared to routine plasma reduction as a strategy to mitigate hemolysis risk from minor incompatible platelet transfusion.

Transfusion medicine: A research agenda for the coming years.

The important scientific and clinical advances of the last century in transfusion medicine include methods for avoiding hemolytic transfusion reactions and preventing transmission of viral infectious diseases. The next great clinical advances will require improving the efficacy and safety of transfusions, as well as acknowledgement of the now proven serious complications of transfusion, including nosocomial infection, thrombosis, inflammation and multi-organ failure. Possible strategies include (1) universal leukoreduction to mitigate transfusion immunomodulation effects and improve storage conditions, (2) minimizing transfusion of ABO incompatible antibodies and cellular/soluble antigens, (3) substituting use of safer solutions for normal saline during apheresis, component infusion and washing (4) new techniques to improve the efficacy and safety of blood components, including improved storage solutions/conditions, supernatant removal by washing, and rejuvenation and (5) maximizing the risk to benefit ratio of transfusions by employing more restrictive and physiologic indications for transfusion (including patient blood management) and improving clinical decision making through novel laboratory and bedside tests such as thromboelastography.

Efficacy of three consecutive therapeutic plasma exchanges in major ABO-incompatible hematopoietic stem cell transplantation.

INTRODUCTION: We retrospectively analyzed data of recipients who underwent three consecutive therapeutic plasma exchanges (TPEs) before major ABO-incompatible (ABOi) hematopoietic stem cell transplantation (HSCT) in our hospital from 2012 to 2017 and evaluated the efficacy of TPE for successful ABOi HSCT. MATERIALS AND METHODS: We investigated the efficacy of TPE in 29 recipients with major ABOi HSCT based on the following: (1) requirement of red blood cell (RBC) transfusion during 100 days, (2) erythrocyte engraftment by reticulocyte count at 3 months, and (3) erythropoiesis recovery by bone marrow examination at 1 month and 3 months after ABOi HSCT. RESULTS: IgM and IgG donor-specific isoagglutinins (DSIs) of 31 cases of TPE were significantly decreased after three consecutive TPEs (IgM median, 1:32 to 1:2, P < .0001; IgG median, 1:256 to 1:8, P < .0001). We divided a total of 31 TPEs into two groups depending on their final DSI titers after TPE (group F, DSI > 1:16; group S, DSI ≤ 1:16). RBC transfusions were required more by group F (median, 12 units) than those by group S (median, 2 units, P = .001). Relative frequencies of erythrocyte engraftment and normal erythropoiesis after ABOi HSCT showed higher tendencies in group S than those in group F. DISCUSSION: Our study demonstrated that three consecutive TPEs were effective in reducing DSI titer in major ABOi HSCT. Reduction of pretransplant DSI in recipients could decrease requirement for RBC transfusion. Three consecutive TPEs are necessary for successful erythrocyte engraftment and normal erythropoiesis in this setting.

Sample collection and sample handling errors submitted to the transfusion error surveillance system, 2006 to 2015.

BACKGROUND: In Canada, transfusion-related errors are voluntarily reported to a tracking system with the goal to systematically improve transfusion safety. This report provides an analysis of sample collection (SC) and sample handling (SH) errors from this national error-tracking system. STUDY DESIGN AND METHODS: Errors from 2006 to 2015 from 23 participating sites were extracted. A survey was conducted to obtain information regarding institutional policies. Samples received in the blood bank were used to calculate rates. "Wrong blood in tube" (WBIT) errors are blood taken from wrong patient and labeled with intended patient's information, or blood taken from intended patient but labeled with another patient's information. RESULTS: A total of 42,363 SC and 14,666 SH errors were reported. Predefined low-severity (low potential for harm) and high-severity errors (potential for fatal outcomes) increased from 2006 to 2015 (low SC, SH: 13-27, 3-12 per 1000; high SC, SH: 1.9-3.7, 0.5-2.0 per 1000). The WBIT rate decreased from 12 to 5.8 per 10,000 between 2006 and 2015 (p < 0.0001). The overall WBIT rate was 6.2 per 10,000, with variability by site (median, 0.3 per 10,000; range, 0-17 per 10,000). Sites with error detection mechanisms, such as regrouping second sample requirements, had lower error rates than sites that did not (SC, SH: 12, 1 per 1000 samples vs. 17, 3 per 1000 samples; p < 0.0001). CONCLUSION: WBIT rates decreased significantly. Low-severity error rates are climbing likely due to increased ascertainment and reporting. Prevention studies are necessary to inform changes to blood transfusion standards to eliminate these errors.

Trends in antigen-negative red blood cell distributions by racial or ethnic groups in the United States.

BACKGROUND: The overall number of red blood cell (RBC) units distributed to hospitals throughout the world and in the United States has decreased lately. This study was performed to determine if the number of antigen-negative RBC units distributed to hospitals has followed this trend. STUDY DESIGN AND METHODS: Stratified by ethnicity, data on total RBC distributions and antigen-negative RBC distributions from six large blood collectors in the United States were obtained from 2009 through 2016. An antigen-negative unit was defined as a unit with a specific RBC phenotype that had been specially ordered as such by a hospital. RESULTS: Overall, 10,103,703 RBC units were distributed by these six blood collectors; 650,516 (6.4%) were distributed as antigen-negative units. While the overall number of RBCs distributed decreased by 27.2% between 2009 and 2016, the number of antigen-negative RBC distributions increased by 39.5%. In each year, the majority of the distributed antigen-negative RBCs were donated by whites. However, antigen-negative RBC units from black or African American donors were distributed in a disproportionately high fraction compared to the overall number of RBCs distributed from these donors. Most of the one through four antigen-negative RBCs were donated by whites. However, as antigen matching became more extensive, the proportion of units distributed from black or African American donors increased such that they were the predominant donors of five or more antigen-negative units. CONCLUSION: Blood collectors will need to be aware of the trend of increasing antigen-negative distributions despite decreased overall distributions.

PAS-C platelets contain less plasma protein, lower anti-A and anti-B titers, and decreased HLA antibody specificities compared to plasma platelets.

BACKGROUND: Platelets (PLTs) collected and stored in PLT additive solution Intersol (PAS-C) are presumed to reduce recipient exposure to donor plasma components; however, the effects of PAS-C on PLT supernatant composition are poorly defined. Therefore, we compared the total protein concentration, isohemagglutinin titers, and HLA antibodies in supernatants of PAS-C PLTs to plasma PLTs. STUDY DESIGN AND METHODS: Apheresis PLTs from group O blood donors were collected into either 100% donor plasma (n = 50) or a mixture of 65% PAS-C/35% donor plasma (n = 50). Within 12 hours of collection, samples of the PLT supernatant were frozen and stored. PLT supernatants were assayed for total protein concentration and anti-A and anti-B titers and screened for HLA antibodies. Samples positive for HLA antibodies were further tested using single-antigen bead assays to determine antibody strength and specificity. RESULTS: Supernatants of PAS-C PLTs had significantly lower total protein concentration and anti-A and anti-B titers compared to plasma PLTs. There was no significant difference in the number of HLA antibody screen-positive PAS-C (3/50) compared to plasma PLT supernatants (2/50); however, the HLA antibody screen-positive supernatants of PAS-C PLTs had fewer HLA specificities (2) compared to those of the plasma PLTs (18). CONCLUSION: Decreased plasma proteins likely underlie lower rates of allergic and febrile, nonhemolytic transfusion reactions from the infusion of PAS-C PLTs. Decreased anti-A and anti-B titers may prevent hemolysis from minor ABO mismatch. Lower HLA antibody specificities may mitigate transfusion-related acute lung injury.

Infusion hemolysis after pediatric major ABO-mismatched bone marrow transplant: Comparison of two red blood cell depletion techniques.

BACKGROUND: During major ABO-mismatched bone marrow transplant (BMT), the infusion of incompatible red blood cells (RBCs) that are present in the bone marrow graft can cause adverse events from hemolysis. RBC depletion of the bone marrow graft can decrease this risk, but the optimal method to prevent hemolysis is unclear. PROCEDURE: We conducted a retrospective cohort study of patients who underwent major ABO-mismatched BMT at a pediatric center and had RBC depletion with either hydroxyethyl starch (HES) sedimentation or Ficoll density gradient separation. Postinfusion hemoglobinuria and creatinine values were compared. RESULTS: Between 2002 and 2016, 37 patients received HES-treated and 16 patients received Ficoll-treated major ABO-mismatched bone marrow grafts. The median residual volume of RBCs was significantly greater with HES-treated grafts (HES 21.0 ml vs. Ficoll 1.4 ml, P < 0.0001). Patients who received HES-treated grafts had a higher prevalence of postinfusion hemoglobinuria (HES 57% vs. Ficoll 6%, P = 0.0009), but renal impairment was rare. Considering only HES-treated grafts, the volume of RBCs was not associated with either postinfusion hemoglobinuria or a creatinine increase. CONCLUSIONS: Ficoll density gradient separation achieves smaller RBC volumes and less postinfusion hemoglobinuria than HES sedimentation, but both can prevent significant hemolysis. Further studies are needed to determine the residual incompatible RBC volume threshold in major ABO-mismatched BMT.

Genotyping to prevent Rh disease: has the time come?

PURPOSE OF REVIEW: In this review, we analyzed the current literature on noninvasive fetal RHD typing to answer the question whether the administration of RhIg to prevent D-alloimmunization during pregnancy can be safely guided by fetal RHD typing. RECENT FINDINGS: Recently the first centers that implemented large-scale nationwide fetal RHD typing in the second trimester for targeted RhIg administration have published their studies evaluating the diagnostic accuracy of their screening programs. These data show that fetal RHD typing in a routine setting is, at least in a population of European descent, accurate enough to guide both antenatal and postnatal immunoprophylaxis. SUMMARY: Depending on the ethnic background and the organization of pregnancy care the decisions regarding RhIg can be safely and cost-effectively based on fetal RHD typing by a duplex real-time PCR. As a result, the unnecessary administration of 40% of antenatal RhIg can be prevented, and cord blood serology can be omitted.

Medical and economic implications of strategies to prevent alloimmunization in sickle cell disease.

BACKGROUND: The pathogenesis of alloimmunization is not well understood, and initiatives that aim to reduce the incidence of alloimmunization are generally expensive and either ineffective or unproven. In this review, we summarize the current medical literature regarding alloimmunization in the sickle cell disease (SCD) population, with a special focus on the financial implications of different approaches to prevent alloimmunization. STUDY DESIGN AND METHODS: A review of EMBASE and MEDLINE data from January 2006 through January 2016 was conducted to identify articles relating to complications of SCD. The search was specifically designed to capture articles that evaluated the costs of various strategies to prevent alloimmunization and its sequelae. RESULTS: Currently, there is no proven, inexpensive way to prevent alloimmunization among individuals with SCD. Serologic matching programs are not uniformly successful in preventing alloimmunization, particularly to Rh antigens, because of the high frequency of variant Rh alleles in the SCD population. A genotypic matching program could offer some cost savings compared to a serologic matching program, but the efficacy of gene matching for the prevention of alloimmunization is largely unproven, and large-scale implementation could be expensive. CONCLUSIONS: Future reductions in the costs associated with genotype matching could make a large-scale program economically feasible. Novel techniques to identify patients at highest risk for alloimmunization could improve the cost effectiveness of antigen matching programs. A clinical trial comparing the efficacy of serologic matching to genotype matching would be informative.

Detection rate of blood group alloimmunization based on real-world testing practices and kinetics of antibody induction and evanescence.

BACKGROUND: Failure to detect non-ABO blood group alloantibodies places patients at risk for hemolytic reactions. Suboptimal alloantibody detection could result from posttransfusion testing performed too early, too late, or not at all. Testing performed too early may precede antibody induction, while testing performed too late could miss antibodies that have evanesced. Taking these factors into account, our goal was to determine the percentage of alloantibodies detected with real-world testing practices. STUDY DESIGN AND METHODS: The alloantibody detection rate in a general hospital setting was determined based on the frequency and timing of antibody testing after red blood cell (RBC) transfusions and rates of antibody induction and evanescence. Intervals to follow up testing after RBC transfusions (n = 561 RBC units in 100 random patients) were determined retrospectively. Best-fit lines and equations for antibody induction and evanescence were computed on previously published data. RESULTS: Nearly half (271/561; 48.3%) of RBC infusions had either no follow-up antibody screen or testing too soon (<30 days) after transfusion to detect alloimmunization. Of the remaining RBC units, 10.3% (58/561) had follow-up testing 30 to 112 days posttransfusion, 28.7% (161/561) were followed up at more than 112 days, and 12.7% (71/561) were tested at both 30 to 112 days and more than 112 days. By inputting these timing data into best-fit line equations for antibody induction and evanescence, we calculated an alloantibody detection rate of 31.6%. CONCLUSION: Posttransfusion antibody testing was inadequately timed for optimal alloantibody detection. Real-world compatibility testing was predicted to detect less than one-third of non-ABO antibodies, thereby exposing patients to risks of mismatched transfusion.