Comparison of the Detection Rate and Specificity of Irregular Red Blood Cell Antibodies Between First-Time Pregnant Women and Women With a History of Multiple Pregnancies Among 18,010 Chinese Women.

Background: There is insufficient evidence to assess the risk of the production of clinically important alloimmune irregular red blood cell (RBC) antibodies in first-time pregnant women. Methods: Using the microcolumn gel antiglobulin method, 18,010 Chinese women with a history of pregnancy and pregnant women were screened for irregular RBC antibodies, and for those with positive test results, antibody specificity was determined. The detection rate and specificity of irregular RBC antibodies in women with a history of multiple pregnancies (two or more) and first-time pregnant women were determined. Results: In addition to 25 patients who passively acquired anti-D antibodies via an intravenous anti-D immunoglobulin injection, irregular RBC antibodies were detected in 121 (0.67%) of the 18,010 women. Irregular RBC antibodies were detected in 93 (0.71%) of the 13,027 women with a history of multiple pregnancies, and antibody specificity was distributed mainly in the Rh, MNSs, Lewis, and Kidd blood group systems; irregular RBC antibodies were detected in 28 (0.56%) of the 4983 first-time pregnant women, and the antibody specificity was distributed mainly in the MNSs, Rh, and Lewis blood group systems. The difference in the percentage of patients with irregular RBC antibodies between the two groups was insignificant (χ 2 = 1.248, P > 0.05). Of the 121 women with irregular RBC antibodies, nine had anti-Mur antibodies, and one had anti-Dia antibodies; these antibodies are clinically important but easily missed because the antigenic profile of the reagent RBCs that are commonly used in antibody screens does not include the antigens that are recognized by these antibodies. Conclusion: Irregular RBC antibody detection is clinically important for both pregnant women with a history of multiple pregnancies and first-time pregnant women. Mur and Dia should be included in the antigenic profile of reagent RBCs that are used for performing antibody screens in the Chinese population.

Cutibacterium acnes contamination does not enhance the proinflammatory profile of platelet concentrates.

BACKGROUND: Cutibacterium acnes, a common anaerobic platelet concentrate (PC) contaminant, has been associated with rare mild adverse transfusion reactions and is often considered a harmless commensal. Notably, C. acnes can cause chronic infections and has been shown to induce the release of proinflammatory cytokines by immune cells. Since elevated concentrations of proinflammatory factors in PCs have been linked to noninfectious adverse reactions, this study aimed to assess whether C. acnes could elicit the release and accumulation of proinflammatory factors during PC storage, thereby enhancing the risk of such reactions. STUDY DESIGN/METHODS: Four ABO-matched buffy coat PCs were pooled and split into six units, each were inoculated with either saline (negative control), a Staphylococcus aureus isolate (positive control, 30 colony forming units [CFU]/unit), or four C. acnes PC isolates (10 CFU/mL) and stored at 20-24°C with agitation. Bacterial counts, platelet activation, and concentration of proinflammatory factors were assessed on days 0, 3, and 5. N = 3. RESULTS: C. acnes counts remained stable, while S. aureus proliferated reaching 108CFU/mL by the end of PC storage. By day 5, no significant differences in platelet activation or proinflammatory cytokine profiles were observed in C. acnes-contaminated PCs compared to the negative control (p > .05), while there was a significant increase (p ≤ .05) in sCD40L concentration (day 3), and platelet activation and IL-8 concentration (day 5) in S. aureus-contaminated units. DISCUSSION: C. acnes contamination does not promote the accumulation of proinflammatory factors in the absence of proliferation during storage and may not enhance the risk of inflammatory reactions when transfused to patients.

Eculizumab for management of hyperhemolysis syndrome in pediatric patients with sickle cell disease: A single-center case series.

Chronic hemolytic anemia and vascular occlusion are hallmarks of sickle cell disease (SCD). Blood transfusions are critical for supportive and preventive management of SCD complications. Patients with SCD are at risk for hyperhemolysis syndrome (HHS), a subtype of delayed hemolytic transfusion reactions. HHS management includes intravenous immunoglobulin, corticosteroids, and avoidance of further transfusions. Not all patients respond to first-line agents. Eculizumab, which blocks terminal complement activation, has been proposed as second-line management of HHS. We describe two patients who received eculizumab for refractory HHS. In our experience, eculizumab is a safe and effective option for refractory pediatric HHS.

A perspective on exogenous redox regulation mediated by transfused RBCs subject to the storage lesion.

Granted with a potent ability to interact with and tolerate oxidative stressors, RBCs scavenge most reactive oxygen and nitrogen species (RONS) generated in circulation. This essential non-canonical function, however, renders RBCs susceptible to damage when vascular RONS are generated in excess, making vascular redox imbalance a common etiology of anemia, and thus a common indication for transfusion. This accentuates the relevance of impairments in redox metabolism during hypothermic storage, as the exposure to chronic oxidative stressors upon transfusion could be exceedingly deleterious to stored RBCs. Herein, we review the prominent mechanisms of the hypothermic storage lesion that alter the ability of RBCs to scavenge exogenous RONS as well as the associated clinical relevance.

Classification of posttransfusion adverse events using a publicly available artificial intelligence system.

BACKGROUND: Correct classification of transfusion reactions is important not only for effective patient care and donor management but also for accurate tracking of events in hemovigilance systems. We compared the ability of a generative artificial intelligence (AI) system to correctly diagnose hypothetical clinical situations as transfusion reactions in comparison to previous studies reporting the accuracy of transfusion medicine (TM) specialists in assessing these cases. METHODS: An AI system was requested to assess 36 case scenarios to provide a diagnosis, severity, and imputability of the transfusion reactions using the CDC National Healthcare Safety Network (NHSN) criteria. Responses were compared to an expert panel's classifications and to the published responses of a panel of TM specialists. Additionally, the AI's responses were compared to the TM specialists' prior attempts to use the TrDDx web-based algorithm for the five most challenging cases. RESULTS: The AI's classification accuracy varied widely depending on the NHSN category. The AI accurately classified all transfusion-associated circulatory overload and transfusion-related acute lung injury cases, exceeding TM specialists' assessments. Conversely, it did not correctly identify any cases in select NHSN categories such as DSTR. Overall accuracy among all diagnostic categories was 48.7% for AI responses versus 72.1% for prior TM specialist responses (p = 0.005). AI-generated responses included non-standard terminology, limited severity assessments, and no imputability determinations. DISCUSSION: A generative AI system may have a role in helping healthcare providers to consider transfusion reaction categories that might be missed, but caution is advised in applying the AI's output to transfusion reaction classification at present.

Blood transfusion reactions and risk of acute kidney injury and major adverse kidney events.

BACKGROUND: Blood transfusion reactions may have a negative impact on organ function. It is unknown whether this association holds true for acute kidney injury (AKI). Therefore, we conducted a cohort study to assess the association between transfusion reactions and the incidence of AKI and major adverse kidney events. METHODS: In this retrospective cohort study, we included patients who received transfusion of blood products during hospitalization at the Hospital Civil of Guadalajara. We analyzed them according to the development of transfusion reactions, and the aim was to assess the association between transfusion reactions and AKI during long-term follow-up. RESULTS: From 2017 to 2021, 81,635 patients received a blood product transfusion, and 516 were included in our study. The most common transfusion was red blood cell packaging (50.4%), fresh frozen plasma (28.7%) and platelets (20.9%); of the 516 patients, 129 (25%) had transfusion reactions. Patients who had transfusion reactions were older and had more comorbidities. The most common type of transfusion reaction was allergic reaction (70.5%), followed by febrile nonhemolytic reaction (11.6%) and anaphylactoid reaction (8.5%). Most cases were considered mild. Acute kidney injury was more prevalent among those who had transfusion reactions (14.7%) than among those who did not (7.8%), p = < 0.01; those with AKI had a higher frequency of diabetes, vasopressors, and insulin use. Transfusion reactions were independently associated with the development of AKI (RR 2.1, p = < 0.02). Major adverse kidney events were more common in those with transfusion reactions. The mortality rate was similar between subgroups. CONCLUSION: In our retrospective cohort of patients who received blood product transfusions, 25% experienced transfusion reactions, and this event was associated with a twofold increase in the probability of developing AKI and some of the major adverse kidney events during long follow-up.

Costs and consequences of over-investigation of minor transfusion reactions.

BACKGROUND: Adverse transfusion events create a direct cost burden on the healthcare system through increased morbidity, mortality, extra investigations for diagnosis, patient treatment and increased use of hospital resources. Understanding the costs and impact minor transfusion reactions have on the healthcare system presents an opportunity for potential cost savings and improved clinical practice. AIMS: To determine the cost associated with investigating minor transfusion reactions, to identify opportunities to improve the management of blood transfusion reactions and potential cost savings through the application of current national guidelines. METHODS: A retrospective review of all suspected transfusion reactions reported to the laboratory over a 6-year period was performed. Reports were assessed for appropriateness of clinical management and associated investigations. Cost of inappropriate investigations and associated blood product discard was calculated using current national tariffs. RESULTS: Of the 274 reports, febrile non-haemolytic transfusion reactions were the most common reactions, with 96 (35%) cases. One hundred forty-eight patients were unnecessarily investigated for suspected transfusion reactions totalling AU$ 32 427.00. The initial total value of partially discarded blood products was AU$ 55 656.00. CONCLUSION: The study demonstrated that unnecessary investigation of minor transfusion reactions adds a significant financial burden to the healthcare system.

Towards the crux of sex-dependent variability in red cell concentrates.

Donor sex can alter the RBC 'storage lesion' progression, contributing to dissimilarities in blood product quality, and thus adverse post-transfusion reactions. The mechanisms underlying the reduced sensitivity of female RBCs to storage-induced stress are partially ascribed to the differential effects of testosterone, progesterone, and estrogen on hemolytic propensity. Contributing to this is the increased proportion of more robust, biologically 'young' subpopulations of RBCs in females. Herein, we discuss the impact of sex hormones on RBCs and the relevance of these biological subpopulations to provide further insight into sex-dependent blood product variability.

Associated criteria used in investigating suspected septic transfusion reactions: A scoping review.

BACKGROUND AND OBJECTIVES: Septic transfusion reactions (STRs) occur as a result of bacterial contamination of blood or blood products, resulting in sepsis. This scoping review aimed to identify, explore and map the available literature on the STR criteria triggering the investigation of STR. MATERIALS AND METHODS: Four electronic databases (MEDLINE, Web of Science, Science Direct, Embase) were searched to retrieve scientific literature reporting such criteria, published from 1 January 2000 to 5 May 2022. Grey literature was also searched from open web sources. RESULTS: Of 1052 references identified, 43 (21 peer-reviewed and 22 grey literature) met the eligibility criteria for inclusion and data extraction after full article screening. Of them, most (27/43, 62.79%) were found to report a single set of criteria, and only two reported four or more sets of criteria. The analysis of 66 sets of criteria collected from the selected references revealed 57 different sets. A few sets of criteria used only one sign and symptom (s/s) (12.12%, n = 8), whereas 16 sets used 7-15 s/s (n = 16/66; 24.24%). Of the total 319 occurrences of s/s associated with the 66 sets of criteria, post-transfusion hyperthermia, body temperature increase and hypotension were the most common s/s categories. Of all the literature available, only one study tested the diagnostic accuracy of the STR criteria. CONCLUSION: This scoping review revealed a substantial variation in criteria used to identify suspected STR. Consequently, conducting further studies to enhance the diagnostic accuracy of these criteria, which trigger STR investigations, is imperative for advancing clinical practice.

Optimizing RBC Transfusion Outcomes in Patients with Acute Illness and in the Chronic Transfusion Setting.

Red blood cell (RBC) transfusion is a common clinical intervention used to treat patients with acute and chronic anemia. The decision to transfuse RBCs in the acute setting is based on several factors but current clinical studies informing optimal RBC transfusion decision making (TDM) are largely based upon hemoglobin (Hb) level. In contrast to transfusion in acute settings, chronic RBC transfusion therapy has several different purposes and is associated with distinct transfusion risks such as iron overload and RBC alloimmunization. Consequently, RBC TDM in the chronic setting requires optimizing the survival of transfused RBCs in order to reduce transfusion exposure over the lifespan of an individual and the associated transfusion complications mentioned. This review summarizes the current medical literature addressing optimal RBC-TDM in the acute and chronic transfusion settings and discusses the current gaps in knowledge which need to be prioritized in future national and international research initiatives.

Knowledge, attitudes and practices of resident doctors and interns on safe blood transfusion practices: a survey-based study

ABSTRACT Introduction: The knowledge of clinicians regarding blood transfusion services may impact patient care and transfusion outcome. The wide variation in transfusion practices among clinicians leads to inappropriate blood product usage and jeopardizes patient safety. Hence, this survey study aimed to assess knowledge, attitude and practice among the residents and interns of safe blood transfusion. Methods: The online survey was based on self-administered questionnaires of three sections: 1. Demography; 2. Knowledge, and; 3. Attitude and Practice. One point was assigned for the correct response of each question in every section. The knowledge score was further categorized into three categories, depending on the points obtained. The participants were also divided into four groups, depending on their experience. The Kruskal-Wallis test was applied to determine the difference of knowledge and practice scores in three designated groups of residents and interns. A p-value of less than 0.05 was considered to be significant. Result: A total of 247 residents and interns participated in this study. Thirteen participants had an incomplete response. Out of 234 participants, Senior Residents (SR), Junior Residents (JR), and interns were 70, 96 and 68 participants, respectively. The knowledge scores of interns were significantly low, as compared to SRs and JRs. Practice scores of interns were also significantly low, compared to the JRs. However, most of the residents and interns (85%) were aware of the pre-transfusion testing. Conclusion: Therefore, the mandatory incorporation of the transfusion medicine subject in the undergraduate curriculum can help the young budding doctors to better implement the patient blood management.

Systematic Workup of Transfusion Reactions Reveals Passive Co-Reporting of Handling Errors.

Introduction: Reporting of transfusion reactions is good practice and required by many guidelines. Errors in the transfusion chain can also lead to severe patient reactions and depend on active error reporting. We aimed to characterize transfusion incidents and asked whether workup of transfusion reactions may also contribute to revealing logistical errors. Methods: Transfusion medical records from 2011 to 2019 at our tertiary medical centre, as well as forensic autopsy reports, digitized sections, and court records from 1990 to 2019 were analysed. A total of 230,845 components were transfused between 2011 and 2019 at our own institution. Results: Overall, 322 transfusion incidents were reported. Of these, 279 were from our own institution, corresponding to a frequency of 0.12% of all transfusions. The distribution of reaction types is consistent with the literature, with allergic reactions (55.9%), febrile-non-hemolytic reactions (FNHTR, 24.2%), hemolytic reactions (3.4%) and other types at smaller frequencies (<3%). Twenty-nine (10.4%) of the 279 reports revealed logistical errors, including hemoglobin above guideline threshold (4.3%), incorrect or non-performed bedside tests (3.2%), inadequate patient identification (2.5%), laboratory and issuing errors, missed product checks or failure to follow recommendations (1.1% each). Eight of 29 (27.5%) of the logistical errors were detected by serendipity during workup of incident reports. In addition, 8/932 autopsy cases under code A14 (medical treatment errors) were found to be transfusion-associated (0.9%). Conclusion: Systematic workup of transfusion incidents can identify previously undetected errors in the transfusion chain. Passive reporting of errors through the recording of side effects may serve as a tool to assess more closely assess the frequency and quality of handling errors in real life, and thus serve to improve patient safety.

Blood Transfusion Complications and Associated Factors Among Blood-Transfused Adult Patients at Debre Markos Comprehensive Specialized Hospital, Ethiopia: A Cross Sectional Study.

Background: Blood transfusion is the infusion of whole blood or its components into the veins of the patient to improve tissue oxygenation and maintain hemostasis. Besides its clinical use, it can pose a risk of transfusion complications with different factors. Purpose: The aim of this study was to assess blood transfusion complications, and associated factors among transfused adult patients at Debre Markos Comprehensive Specialized Hospital, North West Ethiopia, 2022. Materials and Methods: An institution-based cross-sectional study design was conducted on a total of 182 patients from March 20 to June 15, 2022. Patients were enrolled in the study using consecutive sampling method. The socio-demographic and clinical data were collected using a structured questionnaire and data extraction sheet, respectively. About 3 ml of anti-coagulated blood and 30 ml of urine samples were collected to assess transfusion complications. CBC and Coombs test were performed from blood and urinalysis from urine, respectively. Chi-square, Fisher's exact test, and binary logistic regression were done using SPSS version 25. P-values less than 0.05 are declared as statistically significant. Results: An acute transfusion reaction (ATR) was encountered in 12 (6.6%) patients. It was 4.13, 7.78 and 3.96 times more likely to occur among patients with a previous history of transfusion, abortion, and transfused blood stored for more than 20 days compared to their counterparts, respectively. In addition, the odds of developing ATR increase by 2.07 as the number of transfused blood units increases by 1 unit. Conclusion: The incidence of acute transfusion reactions was high. During transfusion, clinicians should closely monitor patients who had history of transfusion, abortion, transfused old blood and more than 1 unit.

Comparison of the conventional tube and erythrocyte-magnetized technology in titration of red blood cell alloantibodies.

BACKGROUND: Erythrocyte alloantibodies are mainly produced after immune stimulation, such as blood transfusion, pregnancy, and transplantation, and are the leading causes of severe hemolytic transfusion reactions and difficulty in blood grouping and matching. Therefore, antibody screening is critical to prevent and improve red cell alloantibodies. Routine tube assay is the primary detection method of antibody screening. Recently, erythrocyte-magnetized technology (EMT) has been increasingly used in clinical practice. This study intends to probe the application and efficacy of the conventional tube and EMT in red blood cell alloantibody titration to provide a reference for clinical blood transfusion. AIM: To investigate the application value of conventional tube and EMT in red blood cell alloantibody titration and enhance the safety of blood transfusion practice. METHODS: A total of 1298 blood samples were harvested from blood donors at the Department of Blood Transfusion of our hospital from March 2021 to December 2022. A 5 mL blood sample was collected in tubing, which was then cut, and the whole blood was put into a test tube for centrifugation to separate the serum. Different red blood cell blood group antibody titers were simultaneously detected using the tube polybrene test, tube antiglobulin test (AGT), and EMT screening irregular antibody methods to determine the best test method. RESULTS: Simultaneous detection was performed through the tube polybrene test, tube AGT and EMT screening irregular antibodies. It was discovered that the EMT screening irregular antibody method could detect all immunoglobulin G (IgG) and immunoglobulin M (IgM) irregular antibodies, and the results of manual tube AGT were satisfactory, but the operation time was lengthy, and the equipment had a large footprint. The EMT screening irregular antibody assay was also conducted to determine its activity against type O Rh (D) red blood cells, and the outcomes were satisfactory. Furthermore, compared to the conventional tube method, the EMT screening irregular antibody method was more cost-effective and had significantly higher detection efficiency. CONCLUSION: With a higher detection rate, the EMT screening irregular antibody method can detect both IgG and IgM irregular antibodies faster and more effectively than the conventional tube method.

Transfusion reactions in neonates and pediatrics: How and why are they different?

Neonates and children are physically as well as physiologically different from adults. They are immunologically vulnerable, and the effects of transfusion can be longstanding, including with respect to their development. The transfusion reactions in children differ from those in adults in the type of reactions, incidence, and severity. The incidence is more than that in adults for the common type of reactions noted in children. Transfusion reactions are most commonly associated with platelets, followed by plasma and red blood cell transfusions in children. Febrile, allergic, and hypotensive reactions or volume overload are the common types in children. Standardizing pediatric adverse transfusion reaction definitions and criteria are necessary to improve studies and reports. Several modifications are needed to be adapted for transfusing blood products in neonates and children to evade the reactions as much as possible and make transfusion safer in this vulnerable population. This article provides a brief articulation of the transfusion reactions in neonatal and pediatric populations describing how they are different from adults.

Approach to Handling Atypical Field Blood Transfusion Scenarios.

Special Operations Forces (SOF) medical personnel have been at the forefront of administering blood products in the austere field medicine environment. These far-forward medical providers regularly treat patients and deliver blood transfusions in some of the world's most extreme environments with minimal resources. A multitude of questions have been raised on this topic based on the unique experiences of senior providers in this field. In this paper, we analyze the available literature and present the recommendations of several experts in transfusion medicine for managing atypical field transfusion scenarios.

Understanding the nursing practices and perspectives of transfusion reaction reporting.

AIMS AND OBJECTIVES: The aim of this study was to investigate nurse perspectives on transfusion-related adverse reaction reporting practices. BACKGROUND: Transfusion-related adverse reaction reporting is an essential component of hemovigilance in Canada, but reporting rates vary and under-reporting of minor transfusion-related adverse reactions exists. To our knowledge, this is the first report of nursing transfusion-related adverse reaction reporting attitudes. DESIGN: This qualitative descriptive study explored the nursing practices and perspectives of transfusion-related adverse reaction reporting by conducting one-on-one interviews with nurses (n = 25) working in adult oncology inpatient and outpatient units. METHODS: Data were thematically analysed; data collection ended when saturation was reached. The COREQ checklist was used to guide this study. RESULTS: The study revealed that the nursing practices of transfusion-related adverse reaction reporting are not standardised to meet the institutional reporting guidelines. Under-reporting of febrile reactions exists at this institution. Major concepts uncovered included the factors impacting nurses' transfusion-related reporting practices, as well as barriers and facilitators to transfusion reporting. CONCLUSION: A practice change in transfusion-related adverse reaction reporting is needed to achieve optimal hemovigilance at this institution. Using the barriers and facilitators identified in this study, institutions can better inform future interventions by employing strategies like TR reporting education in order to improve reporting of transfusion-related adverse reactions in this hospital and other similar institutions. RELEVANCE TO CLINICAL PRACTICE: This study informs clinical practice and decision-making for nurses and nursing educators who manage blood transfusion administration procedures.

Should adding pain, oxygen saturation and physical assessment to vital signs become the new standard of care for detecting blood transfusion reactions?

BACKGROUND AND OBJECTIVES: Clinicians sought to ascertain what frequency of vital signs best detects blood transfusion reactions. This review discusses early and delayed blood product transfusion reaction detection through the lens of scientific literature. METHODS: A comprehensive appraisal of published literature was conducted using Integrative Research Review methodology through June 2022 not limited to English or research in Cumulative Index to Nursing and Allied Health Literature, Cochrane Library of Systematic Reviews, Medline and PubMed. RESULTS: Full-text articles in the final sample included four articles discussing vital signs detecting blood transfusion reactions and four articles reporting the importance of adding physical assessments for early reaction detection. None of the studies provided evidence regarding how often vital signs should be monitored to detect transfusion reactions. No studies included identical screening components for detecting blood product transfusion reactions. Main themes emerged including variations in what was included in vital signs, importance of respiratory assessment, inclusion of physical assessment, nurse documentation and reporting compliance, and patient and family inclusion in transfusion reaction recognition. CONCLUSION: Vital sign components varied across reviewed studies. Respiratory rate and pain were not always included in 'vital signs' to identify transfusion reactions. Only low-level data and no clinical trials loosely informing frequency of vital sign monitoring to transfusion reaction detection were found. Respiratory (to include oxygen saturation, lung sounds and respiratory rate) and pain assessment emerged as crucial to acute and delayed transfusion reaction recognition. The disconnect between 'vital signs' and the varied vital sign components reported to detect transfusion reactions in scientific literature requires further exploration.

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

BACKGROUND AND OBJECTIVES: 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. CASE REPORT: 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. CONCLUSION: To our knowledge, there have been only two other case reports of DHTR and PTP occurring in the same patient.

Laboratory Testing in Transfusion Medicine.

Canine and feline transfusions are life-saving procedures that have become increasingly common in veterinary medicine. Laboratory testing plays a vital role in transfusion medicine, particularly in the prevention and diagnosis of transfusion reactions. Laboratory tests should be used to screen donors for their general health and for the presence of any blood-borne pathogens. Pretransfusion blood typing and compatibility testing make immunologic reactions less likely, and commercial typing and crossmatching kits are now available. Appropriate diagnostic tests in the face of a potential transfusion reaction are important to tailor effective therapy.