Patient Blood Type Research Articles

Detection of ABO Blood Groups From Dentin and Pulp by Using the Absorption-Elution Technique: A Forensic Cross-Sectional Study Among the Population of the Al Jouf Province, Saudi Arabia.

Background and objective Human teeth have a significant forensic importance. As they are the hardest of all human tissues, they are not just chemically stable but also their characteristics are maintained for a long time after death even in the most harsh environmental conditions. Despite the advances made in DNA analysis, fingerprinting, etc., ABO blood grouping still plays a significant role in the forensic practice in the field of personal identification, paternity disputes, and several other scenarios including the identification of mass disaster victims. The term blood groups refers to inherited antigens on the surface of red blood cells (RBCs) detected by specific antibodies. Since tooth pulp contains numerous blood vessels, blood group antigens are most certainly bound to be present in tooth pulp. Various studies have shown that blood group antigens in the pulp and dentin are preserved as long as up to two years after the demise of an individual. Absorption-elution technique has been proven to be the most sensitive, reliable, and consistent method to determine the ABO blood group from both the pulp and dentine.This study aimed toascertain the ABO blood group from both the hard (dentin) as well as the soft tissue (pulp) of the tooth by using the absorption-elution (AE) technique and also to determine if there are any variations in identifying the blood groups from the teeth based on age and gender. Material and methods After obtaining due consent, we included patients of both genders aged between 16-60 years visiting the outpatient department (OPD) clinics at the College of Dentistry for periodontal or orthodontic extractions.One patient's blood type was determined by using the slide agglutination technique before any capillary blood extraction was performed; this patient served as a control. For this investigation, we used the pulp and powdered dentin samples taken from the dental extractions to test for the presence of ABO and Rhesus (Rh) factor antigens by using the AE method. The study samples were compared with the control for blood group determination. Statistical analysis was carried out using the chi-square test with Monte Carlo (MC) simulation to check for any correlation of blood grouping with age and gender. Results The dentin and pulp were shown to have positive blood group antigens for the ABO and Rh factors.While neither pulp nor dentin performed significantly differently in identifying the blood group antigens, pulp showed marginally higher accuracy.There was no discernibledifference regarding gender or age in the dentin or pulp of any of the 45 samples studied. Conclusions For determining an individual's blood type and Rh factor, both the hard (dentin) and soft (pulp) tissues of a tooth are valid sources. This is particularly helpful in forensic medicine cases where teeth are the onlyremains that can be viably used to find out a person's identity.

Abstract WP173: Major ABO Incompatible Platelet Transfusion is Associated With Ischemic Lesions on Brain MRI of Patients With Intracerebral Hemorrhage

Background: We identified that major ABO incompatible platelet transfusions are associated with poor intracerebral hemorrhage (ICH) outcomes, yet the driver for this relationship is unknown and does not appear to be related to impaired hemostasis. Conversely, acute ICH patients are known to develop remote ischemic lesions on brain MRI. These ischemic lesions are associated with poor ICH outcomes, but risk factors for their formation are unknown. We explored whether major ABO incompatible platelet transfusions are associated with these ischemic lesions. Methods: Consecutive spontaneous ICH patients enrolled into a single-center, prospective cohort study between 2009 and 2016 were assessed. Patients receiving an acute, single platelet transfusion within 24 h of admission and a brain MRI during their ICH admission were included. Major ABO incompatible platelet transfusion was the exposure. The presence of ischemic lesions on brain MRI, defined as diffusion restriction >10 mm away from the hematoma was the outcome. Regression models assessed relationships between major ABO-incompatible platelets and ischemic lesions, adjusting for ICH severity and time to MRI. Results: Of 40 ICH patients with an acute platelet transfusion and MRI, the mean age was 67.1 (SD 14.1), 37.5% were female, and 20% received a major ABO incompatible platelet unit. Patients receiving a major incompatible platelet unit were more likely to have ischemic lesions (62.5% vs 21.9%), and there continued to be an association of major ABO-incompatible platelets units with these lesions after adjusting for time to MRI (OR 5.45, 95%CI 1.01-29.30, p=0.04) and ICH score (OR 9.15, 95%CI 1.37-62.67, p=0.02). Sensitivity analyses adjusting for patient blood type did not alter this relationship (OR 17.08, 95%CI 1.34-217.94, p = 0.03). Conclusions: Major ABO incompatible platelet units were associated with remote ischemic DWI lesions. Further work is needed to address the generalizability of our data and to clarify relationships of platelet unit characteristics, cerebral ischemia, and clinical outcomes after ICH.

Blood Transfusion cross match on the basis of Phenotype & Rh Antigen in Donors and Receivers and Analysis of Variations

Background: In brief, knowing the local Rh blood group system frequency helps develop a donor pool for patients who need numerous transfusions and alloantibody-compatible antigen negative blood. Patients have been matched for component blood transfusions using ABO and Rh phenotypes since 2020. Our detection of all blood transfusion-needy patients began. Aim: Our department began To detect C, E, c, and e Rh-specific antigens in multi-transfused patients in 2020. Methods: For the aim of this investigation, 2300 patient samples were obtained from patients who required clinical blood transfusions at our hospital between March 2020 and October 2022. These samples were gathered for the purpose of this investigation. One patient was counted as a single sample even though they required repeated blood transfusions. 1900blood donor samples were provided by the Blood Centre of (duplicated samples were removed based on the identification numbers that were provided by the Blood Centre once they were identified). Results: The study obtained 4200 samples, including 1900donor and 2300patient samples. The allele frequency distribution of blood group antigens in the studied population was compared with the prevalence observed in the present study. The D antigen exhibited a frequency of 99.34% in the studied population, slightly lower than the prevalence observed in the present study at 98.9% (95% CI: 98.5 - 99.0). Conversely, the C antigen was found in 93.1% of the studied population, with a slightly higher prevalence observed in the present study at 99.1% (95% CI: 92.0 - 99.2). Implication: The study suggests serological testing is a cost-effective method for blood transfusion management, identifying Rh phenotypes. Compiling a database of donor Rh genotypes simplifies transfusion selection, reducing unfavorable responses. Pre-transfusion Rh phenotype examination is crucial for matching patient blood type with donor blood, reducing adverse reactions, and improving patient safety. Conclusion: In transfusion applications, serological testing are cost-effective for Rh phenotype identification but not genotypes. Creating a database of blood donors' Rh phenotypes and evaluating each patient before their initial transfusion should lessen adverse reactions and speed up antigen-negative blood availability, saving more patients. Keywords: Blood transfusion, phenotype, Rh antigen, donors, receivers, analysis of variations

The use of cell salvage in adult cardiac surgery at Queen Alia Heart Institute

Background: Objective of the study was to determine the incidence of use cell salvage, indications, efficacy in blood conservation and benefits on recovery after adult cardiac surgery. Methods: This is an observational analysis of adult cardiac surgical patients presenting for cardiac surgery at Queen Alia Heart Institute in the period between September 2023 and December 2023. Patients’ demographics, type of surgery (cardiac pathology), comorbidities, preoperative and postoperative laboratory results, blood transfusion requirements, extubation and intensive care unit (ICU) length of stay were recorded and statistically analysed to determine the effectiveness of cell salvage. Patients were divided into two groups: The cell saver group and the no cell saver group for comparison. Results: Data from 141 adult cardiac surgeries is included in this analysis. Indications for cell saver use were recent anticoagulation (41.4%), more complex surgery (20.7%), high risk of bleeding (13.8%), preoperative anaemia (6.9%), intraoperative major bleeding (6.9%), coagulopathy (6.9%) and rare patient blood type (3.45%). Patients from the cell saver group required blood transfusion 2.1% more than the no cell saver group. There was no significant difference in the length of hospitalization between those who had and those who had not cell saver used during surgery (11.9 and 12 days, respectively). Conclusions: Cell saver was used in one fifth of adult cardiac surgeries. Most common indications for cell saver use during cardiac surgery were recent anticoagulation and more complicated cardiac surgery. The use of cell saver had no impact on postoperative haematocrit or overall time of hospitalization.

ABO-Incompatible Platelet Transfusion Is Associated with Ischemic Lesions on Brain MRI in Patients with Intracerebral Hemorrhage

Background: We have identified that major ABO-incompatible platelet transfusions are associated with poor intracerebral hemorrhage (ICH) outcomes. The underlying drivers for the relationship of these incompatible platelet units on outcome are unknown, yet do not appear to be related to impaired hemostasis. Conversely, ICH patients are known to encounter remote, “silent” ischemic lesions, thought to be from microthrombosis, during their hospitalization. Though these ischemic lesions are well known to associate with poor ICH outcomes, risk factors for its formation are unknown. We explored whether major ABO-incompatible platelet transfusions are associated with acute ischemic lesions on brain MRI during an ICH hospitalization. Methods: Consecutive spontaneous ICH patients enrolled into a single-center, prospective cohort study between 2009 and 2018 were assessed. Patients who received a single platelet transfusion within 24 hours of ICH admission and had a brain MRI during the hospitalization were included in the analysis. Major ABO incompatible platelet transfusion (vs minor mismatch/identical) was defined as the exposure. Presence of remote ischemic lesions, defined as diffusion restriction >10 mm away from the hematoma detected on brain MRI, was the outcome. Regression models were used to assess relationships between major ABO-incompatible platelet unit exposure and acute ischemic brain lesions, adjusting for time from ICH onset to MRI or ICH severity. Results: We identified 40 ICH patients receiving an acute platelet transfusion and having a brain MRI performed during the ICH hospitalization. The mean age was 67.1 (SD 14.1), 37.5% were female, and 20% received a major ABO incompatible platelet unit. Patients receiving a major incompatible platelet unit were more likely to encounter ischemic lesions (62.5% vs 21.9%). We also identified an association of major ABO-incompatible platelets units with acute ischemic brain lesions in our regression models after adjusting for time from ICH symptom onset to MRI (OR 5.45, 95%CI 1.01-29.30, p=0.048) and ICH severity (OR 9.15, 95%CI 1.37-62.67, p=0.024). Additional sensitivity analysis adjusting for patient blood type did not alter this relationship (OR 17.1, 95%CI 1.34-217.9, p = 0.029). Conclusions: Among ICH patients receiving acute platelet transfusions and MRI neuroimaging, major ABO incompatible units were associated with remote ischemic lesions on brain MRI. Further work is needed to address the generalizability of our data and to clarify relationships of platelet unit characteristics, cerebral microthrombosis, and clinical outcomes after ICH.

Tooth Shade and Blood Type: A Descriptive Cross-sectional Study in Tunisia.

The aim of the study was to assess the prevalence of tooth shade and its correlation with blood type. This study analyzed 312 blood donors at the university Hospital in Monastir between November 2021 and June 2022. Both male and female subjects were included, with ages ranging from 18 to 60 years old. Patients with certain dental conditions or habits were excluded from the study. The study recorded various information about blood donors, including gender, age, governorate of origin, tooth shade, and blood type. The tooth shade values were recorded using A-D shade guide. Data input and tabulation were carried out using Microsoft Excel 2016 and SPSS (version 25.0). The study included 312 participants, with 85.58% males and 14.42% females. Tooth shade value B was the most prevalent (43%), and D was the least prevalent (7%). The statistical analysis showed that there was no significant link between tooth shade and blood type. However, there were three statistically significant categories: Blood type B/Tooth shade B, Blood type O/Tooth shade C, and Blood Type O/Tooth shade D. The study examined the link between tooth color and blood type but did not find a significant link. However, significant values were found in different subgroups. A wider selection of subjects and a more rigorous measurement equipment might lead to more favorable results. By considering the patient's blood type alongside other relevant factors, clinicians can enhance the accuracy and precision of tooth shade selection, resulting in harmonious and natural-looking dental restorations. This approach improves patient satisfaction and acceptance.

Frequency analysis of subgroup blood typing and Cis-AB type

The purpose of this study is to prevent side effects of transfusion by analyzing the frequency of subtype blood types in blood type tests. Of the 19,800 cases, 128 (0.59%) cases were classified as subtypes. The distribution of subtype detection in K University Hospital was classified as Cis-AB (39 cases, 30.5%), A₂ (25 cases, 21.6%), A₂B (24 cases, 20.7%), A₁B (13 cases, 11.2%), A₃ (11 cases, 9.5 cases) %), B₃(9 cases, 7.8%), Ag(3 cases, 2.6%), Ax(1 case, 0.95%), Ay(1 case, 0.9%), Bx(1 case, 0.9%), Bel(1 case, 0.9%). Am, Az, and Bm were not detected at all. These subtype blood types are caused by quantitative and qualitative variants of antigenicity on the surface of red blood cells. Finally, the examiner should select blood that matches the patient's blood type and select blood that is not abnormal in the examination and transfuse it to prevent side effects of transfusion in advance.

Patient ABO blood type is a major predictor of a positive DAT following a transfusion reaction.

A direct antiglobulin test (DAT) checks for antibody or complement on the surface of RBCs and is often done following a transfusion reaction. While passive anti-A and anti-B antibodies are known to cause positive DATs, the extent this occurs following transfusion is unknown. DAT results, ABO type, eluate information, and blood product information were recorded on 1097 transfusion reactions at a large academic hospital over 8 years. The effect of patient blood type, product type, and plasma compatibility of blood product transfused on DAT results were determined. Statistical significance was determined using Chi-squared testing. Patient ABO blood type was a strong predictor of a positive DAT, with type O patients having 6.7% positive rate and non-O patients having a positive rate of 20.6% (p< .0001). Plasma compatibility of the product was a strong predictor of a positive DAT, with plasma compatible transfusions having a 9.4% positive rate while plasma incompatible transfusions were positive 44% of the time (p< .0001). Elution studies found that anti-A/B antibodies were the most common antibody identified. Platelets were more likely to be associated with a positive DAT when compared with RBC transfusions (p< .05). These results demonstrate the patient ABO type and plasma incompatibility are strong predictors of positive DAT results following a transfusion reaction. Anti-A and anti-B antibodies are estimated to account for about 50% of positive DATs in this study.

Patient Blood Type Is Associated With Response to Immune Checkpoint Blockade in Metastatic Cancer

BackgroundImmune checkpoint blockade (ICB) has transformed cancer therapy, with long-term responses and a favorable safety profile; however, only a minority of patients respond. Response to ICB is influenced by immune-related genetic factors such as HLA haplotype, potentially including patient blood type and associated differences in diversity of the T-cell repertoire. A minority of patients experience immune-related adverse events (irAEs), with unclear relation to response or resistance.Materials and MethodsIn this single institution study, we aimed to investigate the relationship of time to treatment failure (TTF) with patient blood type and with occurrence of irAEs, among patients with metastatic cancer receiving ICB.ResultsWe found a strong association of improved TTF with presence of irAEs, and also among patients with type O blood, compared with type A/B/AB blood. Among patients with type O blood, TTF was substantially longer among those experiencing an irAE (n = 44; adjusted HR 0.41, 95% CI 0.18,0.96). For patients with type A/B/AB blood, no significant association was present (n = 63; adjusted HR 0.69, 95% CI 0.39,1.21). For type O patients, median TTF of ICB was 13.4 months (95% CI: 3.79 months, NA) vs 2.55 months (95% CI: 1.95 months, 4.95 months) for other patients.ConclusionThis retrospective study of a cohort of patients receiving ICB suggests a preferential benefit among patients with type O blood and, in particular, among patients with type O blood who developed irAEs. Validation in future independent cohorts and investigation of a potential biologic basis for this finding is warranted.

Time to Hemostasis After Trauma and Transfusion by Patient Blood Type.

Although evidence supports an increased risk of mortality after major trauma among patients with type O blood, the relationship between patient blood type and clinical outcomes aside from mortality has not been fully elucidated. To examine the relationship between patient blood type and time to hemostasis after trauma and massive transfusion. A secondary analysis of the Pragmatic, Randomized Optimal Platelet and Plasma Ratios (PROPPR) trial was performed (N = 544). Blood type was dichotomized into type O versus non-type O. It was hypothesized that patients with non-type O blood would achieve hemostasis more quickly owing to the theoretical presence of increased clotting factors. Bivariate analysis and multiple Cox regression were conducted to test this assumption. No significant difference was found in time to hemostasis between patients with type O blood and those with non-type O blood. However, mechanism of injury, diastolic blood pressure, and international normalized ratio affected the time to hemostasis in these trauma patients. This study showed no significant difference in time to hemostasis by blood type.

Analysis of blood type for SARS-CoV-2 and correlation for disease acquisition in various sociodemographic groups including women of childbearing age

BackgroundMultiple studies have occurred to determine if a patient's blood type, Rhesus factor (Rh), and sociodemographic attributes contribute to contracting SARS-CoV-2. True association remains unknown.MethodsInclusion criteria included in-patients who were tested for SARS-CoV-2 with blood type assessed. Study endpoints combined ABO, Rh and all-cause inpatient mortality (ACIM) with testing positivity. Pregnancy status was one of several secondary endpoints evaluated. A logistic regression analysis was used to estimate association.ResultsOf the 27,662 patients who met inclusion criteria, Type A blood was associated with increased positivity [1.01 (1.0-1.21), P = .03]. Type B [1.10 (0.99-1.23), P = .08] and AB [0.98 (0.81-1.19), P = .84] showed no association. When evaluating ACIM, type A [1.18 (0.91-1.52), P = .22], B [1.13 (0.82- 1.56), P = .480], and AB [1.06 (0.62-1.81), P = .839] were not associated with increased mortality. The female subgroup was less likely to test positive [0.88 (0.82-0.986), P = .002]. Black patients demonstrated a higher likelihood of positivity when compared to White [1.96 (1.79-2.14), P < .001]. Non-pregnant women exhibited a 2.5 times greater likelihood of testing positive [2.49 (2.04-3.04), P < .001].ConclusionsThis study confirms results of previous research which showed SARS-Co-V-2 positivity related to blood type. It also confirms more recent research demonstrating inequities related to acquisition of SARS-CoV-2 for certain sociodemographic groups. Larger studies are warranted to confirm and further explore novel pregnancy findings.

Interplay of Antibody and Cytokine Production Reveals CXCL13 as a Potential Novel Biomarker of Lethal SARS-CoV-2 Infection.

The SARS-CoV-2 pandemic is impacting the global population. This study was designed to assess the interplay of antibodies with the cytokine response in SARS-CoV-2 patients. We demonstrate that significant levels of anti-SARS-CoV-2 antibody to receptor binding domain (RBD), nucleocapsid, and spike S1 subunit of SARS-CoV-2 develop over the first 10 to 20 days of infection. The majority of patients produced antibodies against all three antigens (219/255 SARS-CoV-2+ patient specimens, 86%), suggesting a broad response to viral proteins. Antibody levels to SARS-CoV-2 antigens were different based on patient mortality, sex, blood type, and age. Analyses of these findings may help explain variation in immunity between these populations. To better understand the systemic immune response, we analyzed the levels of 20 cytokines by SARS-CoV-2 patients throughout infection. Cytokine analysis of SARS-CoV-2+ patients exhibited increases in proinflammatory markers (interleukin 6 [IL-6], IL-8, IL-18, and gamma interferon [IFN-γ]) and chemotactic markers (IP-10 and eotaxin) relative to healthy individuals. Patients who succumbed to infection produced decreased IL-2, IL-4, IL-12, RANTES, tumor necrosis factor alpha (TNF-α), GRO-α, and MIP-1α relative to patients who survived infection. We also observed that the chemokine CXCL13 was particularly elevated in patients who succumbed to infection. CXCL13 is involved in B cell activation, germinal center development, and antibody maturation, and we observed that CXCL13 levels in blood trended with anti-SARS-CoV-2 antibody levels. Furthermore, patients who succumbed to infection produced high CXCL13 and had a higher ratio of nucleocapsid to RBD antibodies. This study provides insights into SARS-CoV-2 immunity implicating the magnitude and specificity of response in relation to patient outcomes.IMPORTANCE The SARS-CoV-2 pandemic is continuing to impact the global population, and knowledge of the immune response to COVID-19 is still developing. This study assesses the interplay of different parts of the immune system during COVID-19 disease. We demonstrate that COVID-19 patients produce antibodies to three proteins of the COVID-19 virus (SARS-CoV-2) and identify many other immunological proteins that are involved during infection. The data suggest that one of these proteins (CXCL13) may be a novel biomarker for severe COVID-19 that can be readily measured in blood. This information combined with our broad-scale analysis of immune activity during COVID-19 provides new information on the immunological response throughout the course of disease and identifies a novel potential marker for assessing disease severity.

Response to Convalescent Plasma is not Influenced by Patient Blood Type

Background: SARS-CoV2 virus is associated with 580,000 deaths and 32.5 million cases of COVID-19 infection in the United States. Data exist suggesting a correlation between blood type and disease acquisition and severity. No such data exist between blood type and disease response to convalescent plasma therapy. Methods: Forty-four hospitalized COVID-19 patients who were transfused with type-specific convalescent plasma were followed to determine therapeutic response and disease survivability. Statistical significance was determined as to whether a correlation between blood type and convalescent plasma treatment exists. Results: No statistically significant correlation exists between blood type and hospital length of stay or disease survivability in hospitalized COVID-19 patients who received convalescent plasma. Conclusion: Blood type does not influence outcome response to convalescent plasma in hospitalized COVID-19 patients.

How do I…Incorporate a two-sample blood type verification in a pediatric hospital?

The AABB (American Association of Blood Banks) and the College of American Pathologists (CAP) regulations call on blood banks to address the risk of misidentification of a patient's blood type, which can result in transfusion of a mismatched product. Transfusion of mismatched blood product is potentially fatal due to acute hemolytic transfusion reaction and is considered a preventable event. CAP regulations outline options to reduce risk of mistransfusion by either documenting the ABO group of the intended recipient on a second sample collected at a separate phlebotomy, or utilizing a mechanical barrier system or electronic identification verification system that ensures the patient from whom the pretransfusion specimen was collected is the same patient who is about to be transfused. An electronic or barrier system was not available for implementation at our institution, therefore we developed a protocol for a two-sample verification system. The first determination is performed on a current sample and the second by one of the following methods: (a) comparison with previous laboratory records, (b) testing a second sample collected at a time different from the first sample (i.e., laboratory specimen available with a different timestamp, or a new blood sample). We improved our transfusion process and implemented a policy to require a second sample to confirm a patient's blood type. We also implemented workflows to obtain blood type confirmation from history of a second blood type result from previous laboratory records, including a policy to accept previous blood type records from an outside laboratory. We describe a practice change for two-sample verification for type and screen in a large-scale pediatric hospital. We outline specific workflows for pre-operative and emergency transfusion scenarios, and pediatric-specific challenges.

Plants utilized as medicines by residents of Quilombo da Fazenda, Núcleo Picinguaba, Ubatuba, São Paulo, Brazil: A participatory survey

Ethnopharmacological relevanceParticipatory research can help to broaden the understanding of medical systems and beliefs of traditional communities. An ethnopharmacological survey in collaboration with local people focused on plants used in quilombos located in Southeast Region in Brazil identified cultural factors that influence plant and recipe choice. Aim of the study:To investigate the factors related to the therapeutic efficiency of medicinal plants from the perspective of Quilombo da Fazenda residents. Materials and methodsUniversity researchers collaborated with community residents for both aims and methods of the study. The local partners were trained in the gathering of ethnopharmacological data and then selected and interviewed the residents considered experts on the use of medicinal plants. Data on the use of each species were supported by voucher specimens collected by the local partners and university researchers. Participant observations and field diaries by the university researchers supplemented the data. ResultsEight interviewees mentioned 92 medicinal species with 60 therapeutic uses, applied in 208 recipes or remedies. Asteraceae (13 species), Lamiaceae (5) and Urticaceae (5) contributed most medicinal plant species. Of the 12 etic categories of use, the circulatory system category had the highest number of plants mentioned. Decoction was the most commonly used preparation method (66.8%), and most remedies were administered orally (76.4%). Eighty-six recipes included more than one plant species and/or the addition of other components, such as sugar, salt or animal products. Several cultural factors influence medicinal plant use. Popular beliefs on the quality of blood or the humoral properties of plants and illnesses, characteristics of the plants and other factors determine which plant is used and why. ConclusionsThe participatory method identified a large number of factors that influence medicinal plant use: the patient's blood type; the condition of the plant and the disease (hot-cold system); the route of administration and dosage; the preventive uses of the plants; and the influence of other factors, such as the sun, the moon and dew. The participatory approach is useful for gaining insight on the decision processes of medicinal plant use in traditional societies, and also for those communities wanting to document their knowledge with or without the participation of the academy.

Transplant Disparities and Kidney Exchanges: Estimating Quantity and Quality Effects by Patient Blood Type and Sensitization

Kidney exchange programs have been shown to improve the quantity and quality of kidney transplants in the U.S. over the past 15 years. One of the purported benefits of kidney exchange is that it increases access to living donor transplants for hard-to-match patients (i.e. those most likely to die while waiting for another transplant option, all else equal). Moreover, holding exchange transplant quantity and quality fixed, it stands to reason that we achieve the largest welfare gains when such patients are the primary recipients of exchange transplants. In this paper, I analyze the extent to which exchanges have differential impacts on transplant outcomes across patients of different blood types and levels of sensitivity to foreign organs. Exploiting variation in patients' exposure to exchange activity across time and place, I find that exchange has a relatively small beneficial effect on transplant quantity and quality for patients with harder-to-match blood types (types O and B). However, I find that patients who are more sensitized against foreign organs experience larger quantity and quality improvements relative to less-sensitized patients. These findings suggest that exchange programs could generate larger welfare gains by more heavily emphasizing blood type O and B patients in their match runs. Incentivizing participation among compatible patient-donor pairs may be one way to accomplish this goal.

ABO blood type and risk of porcine bioprosthetic aortic valve degeneration: SWEDEHEART observational cohort study

ObjectiveBlood type A antigen on porcine aortic bioprostheses might initiate an immune reaction leading to an increased frequency of structural valve deterioration in patients with blood type B or O....

An instrumental variable approach confirms that the duration of pretransplant dialysis has a negative impact on the survival of kidney transplant recipients and quantifies the risk

Dialysis prior to kidney transplantation may have a detrimental effect on post-transplant outcomes. However, prior studies have not fully characterized the nature of this relationship and may have been subject to residual confounding. Here we investigated the association between pre-transplant dialysis duration and two post-transplant outcomes: all-cause death and death with functioning graft. This was a retrospective, population-based, cohort study in all deceased donor kidney transplants performed in Ontario, Canada, from April 1, 2002 to March 31, 2013. Patient blood type was chosen as an instrumental variable and a two-stage modeling procedure that included a threshold-adjusted Cox proportional hazards model was used to assess the association between dialysis time and the two post-transplant outcomes. Among 4,440 transplant recipients, the relative risk of all-cause death associated with each dialysis year prior to three years was 42% and fell to 5% per additional dialysis year thereafter. For death with functioning graft, each dialysis year before and after 2.8 years increased the relative risk by 31% and 4%, respectively. Peak panel reactive antibody of more than 50% was independently associated with an elevated risk of death with functioning graft but not with the risk of all-cause death. Thus, our findings highlight the urgency to develop strategies to ensure timely transplant listing and to shorten the total dialysis time before transplantation, with the goal of enhancing kidney transplant outcomes.

The Potential and Pitfalls of a Dye-Assisted Paper-Based Assay for Blood Grouping.

Zhang and colleagues (1) recently developed a new method for rapidly determining the ABO type of blood, also known as “blood grouping.” Much of the speed of the technique is attributed to the fact that no centrifugation is needed to separate serum from erythrocytes. In addition to being able to rapidly determine the blood group, the system can be used to determine the presence or absence of several additional antigens on red blood cells (RBCs).2 To evaluate the potential utility of the methods of Zhang and colleagues, one needs to understand the approaches that are currently applied for blood grouping, which vary between laboratories and between countries. The most important role of pretransfusion testing is to ensure that a patient does not receive ABO-incompatible RBCs. To avoid this situation, it is critically important to accurately determine a patient's blood group. Most healthcare facilities use redundant processes to ensure that the patient's blood group has been determined accurately. Blood bank laboratories generally utilize 2 approaches to determine a patient's blood type. The “front type” detects the ABO antigens on erythrocytes, whereas the “back type” detects IgM antibodies to ABO antigens in the serum or plasma. Starting in the early 1900s, these tests have been performed by mixing erythrocytes and serum in tubes followed by visual assessment for the presence of agglutination. Although the tube methods are simple, many institutions have switched to alternative methods employing gel or solid-phase technology. These newer technologies can avoid the deficiencies inherent in tube methods such as variability in pipetting reactants and inconsistency in grading reaction strengths. The gel technology also uses lower sample volumes than tubes (2). Both approaches are appealing to blood banks because they have been largely automated. All of the aforementioned approaches, i.e., tubes, gels, and solid phase, require multistep processes. …

Incompatible type A plasma transfusion in patients requiring massive transfusion protocol: Outcomes of an Eastern Association for the Surgery of Trauma multicenter study.

As part of an Eastern Association for the Surgery of Trauma multi-institutional trial, registry and blood bank data were collected from eight trauma centers for trauma patients (age, ≥ 15 years) receiving emergency release plasma transfusions as part of MTPs from January 2012 to August 2016. Incompatible type A plasma was defined as transfusion to patient blood type B or type AB. Of the 1,536 patients identified, 92% received compatible plasma transfusions and 8% received incompatible type A plasma. Patient characteristics were similar except for greater penetrating injuries (48% vs 36%; p = 0.01) in the incompatible group. In the incompatible group, patients were transfused more plasma units at 4 hours (median, 9 vs. 5; p < 0.001) and overall for stay (11 vs. 9; p = 0.03). No hemolytic transfusion reactions were reported. Two transfusion-related acute lung injury events were reported in the compatible group. Between incompatible and compatible groups, there was no difference in the rates of acute respiratory distress syndrome (6% vs. 8%; p = 0.589), thromboembolic events (9% vs. 7%; p = 0.464), sepsis (6% vs. 8%; p = 0.589), or acute renal failure (8% vs. 8%, p = 0.860). Mortality at 6 (17% vs. 15%, p = 0.775) and 24 hours (25% vs. 23%, p = 0.544) and at 28 days or discharge (38% vs. 35%, p = 0.486) were similar between groups. Multivariate regression demonstrated that Injury Severity Score, older age and more red blood cell transfusion at 4 hours were independently associated with death at 28 days or discharge; Injury Severity Score and more red blood cell transfusion at 4 hours were predictors for morbidity. Incompatible transfusion was not an independent determinant of mortality or morbidity. Transfusion of type A plasma to patients with blood groups B and AB as part of a MTP does not appear to be associated with significant increases in morbidity or mortality. Therapeutic study, level IV.