KEL1 negative red cell transfusions for females of current or future child-bearing potential: A clinical impact and feasibility study.

BACKGROUND: Anti-K is an alloantibody stimulated in response to the KEL1 antigen and may cause hemolytic disease of the fetus and newborn (HDFN). Provision of KEL1 negative blood to females of child-bearing potential was not our practice. We assessed the impact of our policy and assessed feasibility of a KEL1 negative transfusion policy. STUDY DESIGN AND METHODS: This is a cohort study spanning Jan 1, 2007-Jun 30, 2017 in Hamilton, Canada. Data were obtained via our institution's transfusion database. Chart reviews of females age ≤45 with anti-K were performed; data on RBC KEL1 phenotype were obtained from the blood supplier when needed to ascertain the cause of alloimmunization. Descriptive analysis of hospital KEL1 negative inventory demand and supply was performed. RESULTS: From Jan 2007-Jun 2017, 8.6% of all RBC units transfused were provided to females age ≤45. There were 111 females with detectable anti-K. Median age at time of antibody detection was 34 years (interquartile range 27-40) and 28 of 111 (25.2%) patients may have been alloimmunized by transfusion. Of 49 pregnancies, seven had complications due to anti-K. We estimated that our existing RBC inventory (with 16% units known to be KEL1 negative in 2017) is sufficient to meet demand and support a KEL1 negative transfusion policy for females age ≤45. CONCLUSION: Transfusion was responsible for alloimmunization in 25% of females with anti-K over 10 years. Analysis of supply and demand can be used to inform feasibility of a KEL1 negative transfusion policy.

Utilising red cell antigen genotyping and serological phenotyping in sickle cell disease patients to risk-stratify patients for alloimmunisation risk.

BACKGROUND: Alloimmunisation and haemolytic transfusion reactions (HTRs) can occur in patients with sickle cell disease (SCD) despite providing phenotype-matched red blood cell (RBC) transfusions. Variant RBC antigen gene alleles/polymorphisms can lead to discrepancies in serological phenotyping. We evaluated differences between RBC antigen genotyping and phenotyping methods and retrospectively assessed if partial antigen expression may lead to increased risk of alloimmunisation and HTRs in SCD patients at a tertiary centre in Canada. METHODS: RBC antigen phenotyping and genotyping were performed by a reference laboratory on consenting SCD patients. Patient demographic, clinical and transfusion-related data were obtained from a local transfusion registry and chart review after research ethics board approval. RESULTS: A total of 106 SCD patients were enrolled, and 91% (n = 96) showed additional clinically relevant genotyping information when compared to serological phenotyping alone. FY*02N.01 (FY*B GATA-1) (n = 95; 90%) and RH variant alleles (n = 52, 49%; majority accompanied by FY*02N.01) were common, the latter with putative partial antigen expression in 25 patients. Variability in genotype-phenotype antigen prediction occurred mostly in the Rh system, notably with the e antigen (kappa: 0.17). Fifteen (14.2%) patients had a history of alloimmunisation, with five having HTR documented; no differences in clinical outcomes were found in patients with partial antigen expression. Genotype/extended-phenotype matching strategies may have prevented alloimmunisation events. CONCLUSION: We show a high frequency of variant alleles/polymorphisms in the SCD population, where genotyping may complement serological phenotyping. Genotyping SCD patients before transfusion may prevent alloimmunisation and HTRs, and knowledge of the FY*02N.01 variant allele increases feasibility of finding compatible blood.

Electronic patient identification for sample labeling reduces wrong blood in tube errors.

BACKGROUND: Wrong blood in tube (WBIT) errors are a preventable cause of ABO-mismatched RBC transfusions. Electronic patient identification systems (e.g., scanning a patient's wristband barcode before pretransfusion sample collection) are thought to reduce WBIT errors, but the effectiveness of these systems is unclear. STUDY DESIGN AND METHODS: Part 1: Using retrospective data, we compared pretransfusion sample WBIT rates at hospitals using manual patient identification (n = 16 sites; >1.6 million samples) with WBIT rates at hospitals using electronic patient identification for some or all sample collections (n = 4 sites; >0.5 million samples). Also, we compared WBIT rates after implementation of electronic patient identification with preimplementation WBIT rates. Causes and frequencies of WBIT errors were evaluated at each site. Part 2: Transfusion service laboratories (n = 18) prospectively typed mislabeled (rejected) samples (n = 2844) to determine WBIT rates among samples with minor labeling errors. RESULTS: Part 1: The overall unadjusted WBIT rate at sites using manual patient identification was 1:10,110 versus 1:35,806 for sites using electronic identification (p < 0.0001). Correcting for repeat samples and silent WBIT errors yielded overall adjusted WBIT rates of 1:3046 for sites using manual identification and 1:14,606 for sites using electronic identification (p < 0.0001), with wide variation among individual sites. Part 2: The unadjusted WBIT rate among mislabeled (rejected) samples was 1:71 (adjusted WBIT rate, 1:28). CONCLUSION: In this study, using electronic patient identification at the time of pretransfusion sample collection was associated with approximately fivefold fewer WBIT errors compared with using manual patient identification. WBIT rates were high among mislabeled (rejected) samples, confirming that rejecting samples with even minor labeling errors helps mitigate the risk of ABO-incompatible transfusions.

Chloride and Other Electrolyte Concentrations in Commonly Available 5% Albumin Products.

OBJECTIVE: Use of hyperchloremic IV fluids for resuscitation in sepsis may be associated with increased mortality and use of renal replacement therapy. After crystalloids, 5% human albumin represents the second most common resuscitation fluid in the ICU. Its chloride concentration is rarely considered in the clinical setting. This study quantifies previously undocumented chloride concentrations of three 5% albumin solutions using biochemical analysis. DESIGN: We performed blinded analysis of the electrolyte concentration of albumin samples obtained directly from the national blood supplier (Canadian Blood Services). Two-tailed independent t tests were performed for all possible comparative analyses. Analysis of variance testing was performed for relevant three-way comparisons. Significance threshold was set at p less than 0.05. SETTING: All samples were analyzed in the core laboratory at an academic hospital associated with McMaster University in Hamilton, Ontario, Canada. SUBJECTS: We analyzed 65 albumin samples from three available brands obtained through Canadian Blood Services. They include Plasbumin (n = 21), Alburex (n = 24), Octalbin (n = 20). INTERVENTION: Laboratory technologists blinded to product identification measured the concentration of electrolytes, extended electrolytes, lactate, and albumin of each sample using the Abbott ARCHITECT c8000 chemistry analyzer. MEASUREMENTS AND MAIN RESULTS: The mean chloride concentration of Plasbumin, Alburex, and Octalbin, respectively, were 109.4 mmol/L (SD, 1.3), 123.6 mmol/L (SD, 1.3), and 136.8 mmol/L (SD, 0.4). The mean sodium concentration of Plasbumin, Alburex, and Octalbin, respectively, were 139.6 mmol/L (SD, 1.6), 137.3 mmol/L (SD, 2.2), and 149.4 mmol/L (SD, 0.5). The chloride and sodium concentration differed significantly for all two-way comparisons (p < 0.0001) and multiple comparison testing (p < 0.0001). CONCLUSION: This study is the first to identify and document a statistically significant variability in the chloride concentration of available 5% albumin products. This study has also informed a pilot randomized controlled trial examining the effect of administering high chloride versus low chloride fluids in critically ill patients with sepsis.

An international investigation into AB plasma administration in hospitals: how many AB plasma units were infused? The HABSWIN study.

BACKGROUND: Typical practice is to transfuse group-specific plasma units; however, there are situations where group AB plasma (universal donor) is issued to group A, B, or O recipients. If demand for group AB plasma exceeds collections, there is potential for shortage. This project explored the patterns of group AB plasma utilization at hospitals around the world. STUDY DESIGN AND METHODS: The study had two phases: a survey that inquired about hospital group AB plasma inventory, policies, and transfusion practices and a retrospective review of 2014 calendar year data where participants submitted information on plasma disposition including ABO group of unit and recipient, transfusion location, and select indications. Recruitment occurred through snowball sampling. Descriptive analyses were performed. RESULTS: Survey data were received from 25 centers across 10 countries; of those, 15 participants contributed to the data collection component. These 15 centers transfused a total of 43,369 AB plasma units during the study period. Only 1496 of 5541 (27%) group AB plasma units were transfused to group AB recipients. Transfusion policies, practices, and patterns were variable across sites. CONCLUSION: Group AB plasma units are frequently transfused to non-AB recipients. Whether transfusing 73% of group AB plasma units to non-AB recipients is the ideal inventory management strategy remains to be determined.

An international investigation into O red blood cell unit administration in hospitals: the GRoup O Utilization Patterns (GROUP) study.

BACKGROUND: Transfusion of group O blood to non-O recipients, or transfusion of D- blood to D+ recipients, can result in shortages of group O or D- blood, respectively. This study investigated RBC utilization patterns at hospitals around the world and explored the context and policies that guide ABO blood group and D type selection practices. STUDY DESIGN AND METHODS: This was a retrospective study on transfusion data from the 2013 calendar year. This study included a survey component that asked about hospital RBC selection and transfusion practices and a data collection component where participants submitted information on RBC unit disposition including blood group and D type of unit and recipient. Units administered to recipients of unknown ABO or D group were excluded. RESULTS: Thirty-eight hospitals in 11 countries responded to the survey, 30 of which provided specific RBC unit disposition data. Overall, 11.1% (21,235/191,397) of group O units were transfused to non-O recipients; 22.6% (8777/38,911) of group O D- RBC units were transfused to O D+ recipients, and 43.2% (16,800/38,911) of group O D- RBC units were transfused to recipients that were not group O D-. Disposition of units and hospital transfusion policy varied within and across hospitals of different sizes, with transfusion of group O D- units to non-group O D- patients ranging from 0% to 33%. CONCLUSION: A significant proportion of group O and D- RBC units were transfused to compatible, nonidentical recipients, although the frequency of this practice varied across sites.