otpb functions in a Lef1-dependent transcriptional network required for expression of the stress response inhibitor crhbp in the zebrafish hypothalamus.

The vertebrate hypothalamus regulates physiological and behavioral responses to environmental stimuli through the function of evolutionarily-conserved neuronal subpopulations. Our previous work found that mutation of zebrafish lef1 , which encodes a transcriptional mediator of the Wnt signaling pathway, leads to the loss of hypothalamic neurons and behavioral phenotypes that are both associated with stress-related human mood disorders However, the specific Lef1 target genes that link neurogenesis to behavior remain unknown. One candidate is otpb , which encodes a transcription factor with known roles in hypothalamic development. Here we show that otpb expression in the posterior hypothalamus is Lef1-dependent, and that like lef1 , its function is required for the generation of crhbp + neurons in this region. Transgenic reporter analysis of a crhbp conserved noncoding element suggests that otpb participates in a transcriptional regulatory network with other Lef1 targets. Finally, consistent with a role for crhbp in inhibiting the stress response, zebrafish otpb mutants exhibit decreased exploration in a novel tank diving assay. Together our findings suggest a potential evolutionarily-conserved mechanism for the regulation of innate stress response behaviors through Lef1-mediated hypothalamic neurogenesis.

A transgene targeted to the zebrafish nkx2.4b locus drives specific green fluorescent protein expression and disrupts thyroid development.

BACKGROUND: With the goal of labeling and manipulating the zebrafish hypothalamus, we sought to target a green fluorescent protein (gfp) transgene to the expression domains of nkx2.4b, a gene expressed during hypothalamic and thyroid development. We combined transcription activator-like effector nucleases (TALENs)-mediated mutagenesis with a targeting construct to enable insertion of a gfp transgene into the endogenous nkx2.4b genomic locus. RESULTS: Injection of TALENs targeted to the first exon of nkx2.4b created a predicted null allele, and homozygous mutant embryos displayed loss of thyroid markers. From embryos injected with both TALENs and a targeting construct carrying a gfp transgene, we recovered a line in which GFP was expressed specifically in the hypothalamus and thyroid. Fish homozygous for this allele lacked exon 1 of nkx2.4b and exhibited hypothyroid phenotypes. CONCLUSIONS: By combining TALENs injections with a targeting construct that contained a gfp transgene, we were able to recover an allele in which GFP is expressed in the nkx2.4b expression domains, with homozygous phenotypes suggesting the creation of a loss-of-function transgenic line. These results demonstrate the creation of a useful tool for studying hypothalamus and thyroid development.

Effect of red blood cell storage duration on major postoperative complications in cardiac surgery: A randomized trial.

BACKGROUND: Although observational studies suggest an association between transfusion of older red blood cell (RBC) units and increased postoperative risk, randomized trials have not supported this. The objective of this randomized trial was to test the effect of RBC storage age on outcomes after cardiac surgery. METHODS: From July 2007 to May 2016, 3835 adults undergoing coronary artery bypass grafting, cardiac valve procedures, or ascending aorta repair, either alone or in combination, were randomized to transfusion of RBCs stored for ≤14 days (younger units) or for ≥20 days (older units) intraoperatively and throughout the postoperative hospitalization. According to protocol, 2448 patients were excluded because they did not receive RBC transfusions. Among the remaining 1387 modified intent-to-treat patients, 701 were randomized to receive younger RBC units (median age, 11 days) and the remaining 686 to receive older units (median age, 25 days). The primary endpoint was composite morbidity and mortality, analyzed using a generalized estimating equation (GEE) model. The trial was discontinued midway owing to enrollment constraints. RESULTS: A total of 5470 RBC units were transfused, including 2783 in the younger RBC storage group and 2687 in the older RBC storage group. The GEE average relative-effect odds ratio was 0.77 (95% confidence interval [CI], 0.50-1.19; P = .083) for the composite morbidity and mortality endpoint. In-hospital mortality was lower for the younger RBC storage group (2.1% [n = 15] vs 3.4% [n = 23]), as was occurrence of other adverse events except for atrial fibrillation, although all CIs crossed 1.0. CONCLUSIONS: This clinical trial, which was stopped at its midpoint owing to enrollment constraints, supports neither the efficacy nor the futility of transfusing either younger or older RBC units. The effects of transfusing RBCs after even more prolonged storage (35-42 days) remains untested.

Real Age: Red Blood Cell Aging During Storage.

BACKGROUND: During cold storage, some red blood cell (RBC) units age more rapidly than others. Yet, the Food and Drug Administration has set a uniform storage limit of 42 days. Objectives of this review are to present evidence for an RBC storage lesion and suggest that functional measures of stored RBC quality-which we call real age-may be more appropriate than calendar age. METHODS: During RBC storage, biochemical substances and byproducts accumulate and RBC shape alters. Factors that influence the rate of degradation include donor characteristics, bio-preservation conditions, and vesiculation. Better understanding of markers of RBC quality may lead to standardized, quantifiable, and operationally practical measures to improve donor selection, assess quality of an RBC unit, improve storage conditions, and test efficacy of the transfused product. RESULTS: The conundrum is that clinical trials of younger versus older RBC units have not aligned with in vitro aging data; that is, the units transfused were not old enough. In vitro changes are considerable beyond 28 to 35 days, and average storage age for older transfused units was 14 to 21 days. CONCLUSIONS: RBC product real age varies by donor characteristics, storage conditions, and biological changes during storage. Metrics to measure temporal changes in quality of the stored RBC product may be more appropriate than the 42-day expiration date. Randomized trials and observational studies are focused on average effect, but, in the evolving age of precision medicine, we must acknowledge that vulnerable populations and individuals may be harmed by aging blood.

Effect of bone marrow CD34+cells and T-cell subsets on clinical outcomes after myeloablative allogeneic hematopoietic cell transplantation.

Donor-derived T-cells mediate graft-versus-leukemia effect, immune reconstitution, and graft-versus-host-disease (GvHD) after allogeneic hematopoietic cell transplantation (HCT). We examined the association of donor cell subsets with outcomes in recipients of myeloablative allogeneic HCT using bone marrow (BM, N = 359) grafts from 2002 to 2014 with related or unrelated donors. Analysis considered pre-infusion graft total nucleated cell (TNC), CD34+ CD3+, CD4+, CD8+ doses. Most patients received busulfan-cyclophosphamide or etoposide-total body irradiation conditioning for acute leukemia or myelodysplastic syndrome. Calcineurin inhibitor-mycophenolate mofetil (CNI-MMF) (49%) or calcineurin inhibitor-methotrexate (CNI-MTX) (47%) were used for GvHD prophylaxis. In multivariable analysis, higher CD34+ dose was associated with platelet engraftment (P < 0.001) and lymphocyte recovery (P = 0.006). There was no association of donor cell subsets with donor chimerism or overall survival. In conclusion, BM graft composition is associated with myeloablative allogeneic HCT outcomes and future studies to evaluate optimal graft composition are needed.

Astrocyte-enriched feeder layers from cryopreserved cells support differentiation of spontaneously active networks of human iPSC-derived neurons.

BACKGROUND: Human induced pluripotent stem cell (hiPSC)-derived neuronal cultures are a useful tool for studying the mechanisms of neurological disorders and developing novel therapeutics. While plating hiPSC-derived neuronal progenitors onto glial feeder layers prepared from rodent cortex has been reported to promote functional differentiation of neuronal networks, this has not been examined in detail. NEW METHOD: Here we describe a method of using cryopreserved cells from primary cultures for generation of mouse astrocyte-enriched, neuron-free feeder layers that grow from 10% to 100% confluence in 1 week. RESULTS: Electrophysiological analysis demonstrated that compared to biochemical substrates alone, astrocyte-enriched feeder layers support more rapid differentiation of hiPSC-derived progenitors into excitable neurons that form spontaneously active networks in culture. There was a positive correlation between the degree of astroglial confluence at the time of progenitor plating and the average frequency of postsynaptic currents 3 weeks after plating. One disadvantage to plating on 100% confluent feeder layers was a high incidence of the astroglial layer with the overlying neurons detaching from the coverslips during transfer to the recording chamber. COMPARISON WITH EXISTING METHOD(S): Prevailing methods using primary glial feeder layers can result in possible contamination with rodent neurons and an unpredictable rate of growth. We provide a reliable method of generating mouse astroglial feeder layers from cryopreserved primary cultures to support differentiation of hiPSC-derived neurons. CONCLUSIONS: The ability to make astrocyte-enriched feeder layers of defined confluence from cryopreserved primary cultures will facilitate the use of human stem cell derived neuronal cultures for disease modeling.

Red blood cell storage and in-hospital mortality: a secondary analysis of the INFORM randomised controlled trial.

BACKGROUND: No randomised trials have addressed whether exposure to red blood cells (RBCs) stored longer than 35 days is associated with harm in patients. We aimed to assess the risk of in-hospital mortality associated with transfusing blood stored longer than 35 days. METHODS: We did a secondary analysis of the INforming Fresh versus Old Red cell Management (INFORM) trial, a pragmatic, multicentre, randomised controlled trial of patients (≥18 years) admitted to one of six hospitals in Australia, Canada, Israel, and the USA and expected to need RBC transfusions. Patients were randomly assigned (2:1) to receive blood in inventory stored for the longest time (standard care) or the shortest time, using a random allocation schedule and stratified by centre and patient ABO blood group. The primary objective of the INFORM trial was to assess all-cause in-hospital mortality in patients with blood group A and O who were transfused. For our exploratory secondary analysis, we classified individuals into one of three mutually exclusive exposure categories on the basis of the maximum storage duration of any blood unit patients had received on each day in hospital: exclusively exposed to RBCs stored no longer than 7 days, exposed to at least one unit of RBCs stored 8-35 days, and exposed to least one unit of RBCs stored longer than 35 days. Our primary objective was to determine the effect on risk of in-hospital death of time-dependent exposure to RBCs stored longer than 35 days compared with exclusive exposure to RBCs stored no longer than 7 days, both in patients of blood groups A and O and all patients. The INFORM trial is registered as an International Standard Randomised Controlled Trial, number ISRCTN08118744. FINDINGS: Between April 2, 2012, and Oct 21, 2015, 31 497 patients were recruited, and 24 736 patients were eligible for inclusion in this analysis. We excluded nine patients for whom information about the storage duration of transfused blood was missing and one patient whose sex was unknown. 4480 (18%) patients were exposed to RBCs with longest storage, 1392 (6%) patients were exposed exclusively to RBCs with shortest storage, and 18 854 (76%) patients were exposed to RBCs stored 8-35 days. Median follow-up was 11 days (IQR 6-20). Exposure to RBCs stored longer than 35 days was not associated with increased risk of in-hospital death compared with exclusive exposure to the freshest RBC units after adjusting for demographic variables, diagnosis category, and blood product use history (in patients with blood group A or O: hazard ratio 0·94, 95% CI 0·73-1·20, p=0·60; in all patients: 0·91, 0·72-1·14, p=0·40). The risk of in-hospital death also did not differ between patients exposed to blood stored 8-35 days and patients exposed to blood stored 7 days or less (in patients with blood group A or O: 0·92, 0·74-1·15, p=0·48; in all patients: 0·90, 0·73-1·10, p=0·29). INTERPRETATION: These data provide evidence that transfusion of blood stored for longer than 35 days has no effect on in-hospital mortality, which suggests that current approaches to blood storage and inventory management are reasonable. FUNDING: Canadian Institutes for Health Research, Canadian Blood Services, and Health Canada.

Effect of Short-Term vs. Long-Term Blood Storage on Mortality after Transfusion.

BACKGROUND: Randomized, controlled trials have suggested that the transfusion of blood after prolonged storage does not increase the risk of adverse outcomes among patients, although most of these trials were restricted to high-risk populations and were not powered to detect small but clinically important differences in mortality. We sought to find out whether the duration of blood storage would have an effect on mortality after transfusion in a general population of hospitalized patients. METHODS: In this pragmatic, randomized, controlled trial conducted at six hospitals in four countries, we randomly assigned patients who required a red-cell transfusion to receive blood that had been stored for the shortest duration (short-term storage group) or the longest duration (long-term storage group) in a 1:2 ratio. Only patients with type A or O blood were included in the primary analysis, since pilot data suggested that our goal of achieving a difference in the mean duration of blood storage of at least 10 days would not be possible with other blood types. Written informed consent was waived because all the patients received treatment consistent with the current standard of care. The primary outcome was in-hospital mortality, which was estimated by means of a logistic-regression model after adjustment for study center and patient blood type. RESULTS: From April 2012 through October 2015, a total of 31,497 patients underwent randomization. Of these patients, 6761 who did not meet all the enrollment criteria were excluded after randomization. The primary analysis included 20,858 patients with type A or O blood. Of these patients, 6936 were assigned to the short-term storage group and 13,922 to the long-term storage group. The mean storage duration was 13.0 days in the short-term storage group and 23.6 days in the long-term storage group. There were 634 deaths (9.1%) in the short-term storage group and 1213 (8.7%) in the long-term storage group (odds ratio, 1.05; 95% confidence interval [CI], 0.95 to 1.16; P=0.34). When the analysis was expanded to include the 24,736 patients with any blood type, the results were similar, with rates of death of 9.1% and 8.8%, respectively (odds ratio, 1.04; 95% CI, 0.95 to 1.14; P=0.38). Additional results were consistent in three prespecified high-risk subgroups (patients undergoing cardiovascular surgery, those admitted to intensive care, and those with cancer). CONCLUSIONS: Among patients in a general hospital population, there was no significant difference in the rate of death among those who underwent transfusion with the freshest available blood and those who underwent transfusion according to the standard practice of transfusing the oldest available blood. (Funded by the Canadian Institutes of Health Research and others; INFORM Current Controlled Trials number, ISRCTN08118744 .).

Cold Antibodies in Cardiovascular Surgery: Is Preoperative Screening Necessary?

OBJECTIVES: Cold antibodies (CAs) are rarely significant for transfusion, but they can cause complications under the hypothermic conditions of cardiovascular surgery. The purpose of this study was to determine the incidence of such complications. METHODS: Patients with CAs who underwent cardiovascular surgery were identified, and their records were reviewed for intraoperative complications attributable to CAs. RESULTS: Over 14.5 years, of the 47,373 patients who underwent cardiovascular surgery, 99 had CAs before or within 30 days after surgery. Ninety-seven patients had hypothermic surgery, and intraoperative agglutination was noted in four; two of these cases were never reported to the transfusion service. CONCLUSIONS: The incidence of intraoperative complications among our patients with CAs was only 4%; therefore, the use of special testing protocols for the preoperative identification of CAs is neither necessary nor justified. Patient risk is best managed by preoperative clinical evaluation for potentially pathogenic CAs and intraoperative vigilance for agglutination.

Rationale and Design of the Informing Fresh versus Old Red Cell Management (INFORM) Trial: An International Pragmatic Randomized Trial.

Although red blood cell transfusion is a potentially lifesaving intervention in severely anemic and acutely bleeding patients, some observational studies have suggested that prolonged red cell storage before transfusion is associated with harm. INFORM is a large, pragmatic, randomized controlled trial comparing the effect of the shorter storage with longer storage red blood cell transfusions on inhospital mortality in hospitalized patients who require a blood transfusion. The trial is being conducted in centers in Australia, Canada, Israel, and the United States and is expected to enroll 31497 patients. If the results of INFORM indicate that shorter storage red blood cell transfusion is associated with superior outcomes compared with standard issue red blood cell transfusion, consideration may be given to shortening blood storage times. If, in contrast, the INFORM trial provides no evidence of harm from longer storage red blood cells, clinicians and patients may be reassured that current blood inventory management strategies are appropriate.

Cocaine-induced microangiopathic hemolytic anemia mimicking idiopathic thrombotic thrombocytopenic purpura: a case report and review of the literature.

Our understanding of the pathogenesis of idiopathic thrombotic thrombocytopenic purpura (TTP) has increased, but remains incomplete, particularly with respect to cases of suspected TTP that are either unresponsive to therapeutic plasma exchange (TPE) or have normal ADAMTS13 (a disintegrin-like and metalloprotease with thrombospondin type 1 motif 13) activity. A 53-year-old woman presented with severe anemia (hemoglobin 1.8 g/dL) and clinical and laboratory findings consistent with TTP in conjunction with acute cocaine use. The patient was treated with TPE until the pre-treatment ADAMTS13 activity was reported as normal without evidence of an inhibitor. TPE was stopped and the patient continued to improve without treatment. This patient's microangiopathic hemolytic anemia (MAHA) appeared to be secondary to cocaine use. The proposed pathogenesis is likely a combination of cocaine-induced vasoconstriction, vascular damage, platelet activation, and procoagulation. This is the fifth published report of cocaine-induced MAHA and to our knowledge the first with ADAMTS13 testing.

How do we use molecular red blood cell antigen typing to supplement pretransfusion testing?

The molecular basis of many blood group antigens is known, and it provides a means for predicting the red blood cell phenotype. Molecular typing methods are useful when serologic typing cannot be performed, due to sample or reagent limitations. We discuss the implementation of a commercial molecular typing assay at our Transfusion Service, the indications for testing, and the advantages and drawbacks of the assay. We also present our algorithm for selecting candidates for testing.

Red blood cell storage: how long is too long?

Red blood cells (RBCs) undergo biochemical and structural changes during storage, commonly referred to as the "storage lesion." Evidence suggests that the longer the RBC product is stored, the less effective is the transfused blood. Many studies linking morbidity to transfusion have not considered duration of RBC storage as a variable that may modulate the effect. In addition, the effects of supply and demand and RBC inventory management strategies have been incompletely investigated. It is possible to envision a blood management system based on modern inventory management strategies that could greatly reduce storage duration.

Erythrocyte storage duration is not associated with increased mortality in noncardiac surgical patients: a retrospective analysis of 6,994 patients.

BACKGROUND: More than 5 million patients receive erythrocyte transfusions in the United States every year. Previous studies linked the storage duration of allogeneic erythrocytes to the risk of severe postoperative complications, especially after cardiac or trauma surgery. Limited data are available for noncardiac surgical patients. We therefore evaluated the association between storage duration of transfused erythrocytes and postoperative all-cause mortality among general surgery patients. METHODS: Perioperative data corresponding to 63,319 adult, general surgery patients were obtained from our registry and merged with blood product data. Patients receiving solely leukocyte-reduced, allogeneic erythrocyte transfusions were included. Multivariable Cox proportional hazards regression was used to characterize the relationship between median erythrocyte storage duration and postoperative mortality rate, adjusting for characteristics plausibly influencing the storage duration of erythrocytes. RESULTS: Of the 6,994 patients included in the final analysis, 23, 44, 11, 9, and 13% received 1, 2, 3, 4, and ≥5 erythrocyte units, respectively. The authors found no evidence that increasing median storage duration was associated with a difference in the risk of postoperative mortality (hazard ratio, 0.99 [0.94-1.04]; P = 0.64). Analyzing the mean storage duration of erythrocyte units as a function of year of transfusion, the authors demonstrate a relevant decrease in utilization of the oldest blood units, whereas young blood storage duration remains nearly unchanged. CONCLUSION: The authors' study supports the recent literature in surgical and medical patients and underlines the importance of sufficiently powered randomized trials to finally resolve the erythrocyte storage duration debate.

An evolution in blood management: past, present, and future.

Blood management is a concept that adopts a principle of improving patient outcome by integrating all available techniques to ensure safety, availability, and appropriate allocation of blood products. This constitutes a model of multidisciplinary care where the changes in culture are system directed on the basis of evidence-based medicine. There are about 14% US hospitals where any kind of blood management program exists, although the idea remains the same but the programs vary in their execution, implementation, and ultimately providing the value to patients. In this article, we have described our experience of creating a patient-centric, cost-effective, evidence-based, and multipronged program creation with scalable results. The use of data, education, process improvement, engagement, and accountability of caregivers have resulted in sustained results and helped in creating a comprehensive blood management program.

Transfusion increases the risk for vasoplegia after cardiac operations.

BACKGROUND: Perioperative vasoplegia is associated with increased morbidity. Red blood cell (RBC) transfusion increases plasma concentrations of inflammatory mediators, possibly contributing to the development of vasoplegia. We investigated the prevalence of mild and profound postoperative vasoplegia, identified factors associated with its development, and examined the role of RBC and component transfusion on the occurrence of postoperative vasoplegia. METHODS: Between January 1, 2000, and January 1, 2007, 25,960 patients underwent on-bypass cardiac surgical procedures. The incidence of vasoplegia was defined as (1) mild vasoplegia requiring norepinephrine infusion for blood pressure support on the day of operation and postoperative day 1, and (2) profound vasoplegia requiring vasopressin, with or without concomitant norepinephrine infusion, on the day of operation and postoperative day 1. Separate logistic regression models were used to model risk factors for development of mild and profound vasoplegia. RESULTS: RBC transfusion increased risk-adjusted odd ratios (ORs) of developing mild vasoplegia (1.07 [95% confidence limits (CL), 1.05, 1.10]; p<0.001) and profound vasoplegia (1.38 [1.31, 1.46] p<0.001). The risk-adjusted ORs (95% CL) for mild vasoplegia and profound vasoplegia were similarly increased by fresh-frozen plasma (OR, 1.24 [1.10, 1.41], p<0.001; and OR, 1.20 [1.13, 1.29], p<0.001) and platelet transfusion (OR, 1.39 [1.25, 1.54], p<0.001; and OR, 1.22 [1.14, 1.31], p<0.001), respectively. CONCLUSIONS: Red blood cells, fresh-frozen plasma, and platelet transfusion increased the prevalence of vasoplegia. RBC transfusion exhibited a dose-dependent response for developing vasoplegia with each RBC unit transfused. Further investigation is necessary to determine whether prophylactic use of vasopressor support in the setting of transfusion can ameliorate risk and effect outcomes.

Predicting hematopoietic stem cell mobilization failure in patients with multiple myeloma: a simple method using day 1 CD34+ cell yield.

Early and reliable prediction of the likelihood of achieving adequate stem cell collection for autologous stem cell transplantation (ASCT) in patients with multiple myeloma (MM) would improve collection efficiency, prevent unnecessary aphereses, and permit appropriate treatment alterations. No previous study has reported a threshold CD34+ cell collection quantity on Day 1 or 2 of leukapheresis that could predict successful stem cell collection. We performed a retrospective analysis of all MM patients undergoing first attempt of stem cell collection at our institution from 2001 through 2008. Recursive partitioning analysis was used to identify Day 1 or Day 1+2 CD34+ collection quantity that predicted failure to reach target ≥ 2 × 10(6) CD34+ cells/kg within five days of collection. Totally, 172 patients were included in the analysis. Patients underwent mobilization with G-CSF or G-CSF+ chemotherapy. 23 of 172 patients (13.4%) failed to collect sufficient (≥ 2 × 10(6) CD34+ cells/kg) CD34+ cells after five days of apheresis: 22 of 29 who collected ≤ 0.70 × 10(6) CD34+ cells/kg and 1 of 143 who collected > 0.70 × 10(6) CD34+ cells/kg (75.9% vs. 0.7%, P < 0.001) on Day 1. Collection failure occurred in 23 of 30 patients who collected ≤ 1.54 × 10(6) CD34+ cells/kg and 0 of 142 who collected >1.54 × 10(6) CD34+ cells/kg (76.7% vs. 0%, P < 0.001) on Days 1 + 2. Day 1 CD34+ cell collection quantity identifies patients unlikely to achieve adequate collection for ASCT. Patients who collect ≤ 0.70 × 10(6) CD34+ cells/kg on day 1 could be considered for treatment modifications to improve CD34+ collection, such as early administration of plerixafor or large volume apheresis.

Safety of the blood supply in a rural area of China.

OBJECTIVE: To determine the sensitivity and specificity of tests for hepatitis B surface antigen (HbsAg), hepatitis C virus (HCV), and syphilis conducted by laboratories of 3 blood collection organizations in a rural area of China. METHODS: From October to December 2003, 1068 samples were collected from blood donors presenting to the 3 collection centers. All samples were tested twice using 2 different test kits for HBsAg, HCV, and syphilis. An aliquot was sent to the China National Center for Clinical Laboratories to confirm the local test results. Sensitivities and specificities of the 3 local blood centers/banks were calculated using the results of the National Center for Clinical Laboratories as the gold standard. RESULTS: The sensitivity of the 3 blood collection center/banks ranged from 0% to 63.2% for HBsAg. For HCV, the sensitivity was 0%, and for syphilis, ranged from 0% to 85.7%. There were no HBsAg positives in one of the blood center/banks, and no syphilis positives in the other. Thus, sensitivity could not be measured for these tests in these 2 facilities. Combining all 3 tests, the overall sensitivity was 55.6%. The specificity was 100%. CONCLUSIONS: The sensitivity of the local laboratories was inadequate and could cause possible infection for an unacceptable number of blood recipients. Action needs to be taken to improve the quality of testing to ensure the safety of the rural blood supply.

Toward extended phenotype matching: a new operational paradigm for the transfusion service.

BACKGROUND: Conventional pretransfusion testing uses hemagglutination to ensure donor-recipient compatibility for ABO/D status and recipient alloantibodies. While screening large numbers of donor units for multiple antigens by hemagglutination is impractical, novel methods of DNA analysis permit the rapid determination of an extended human erythrocyte antigen (xHEA) phenotype. A prospective observational study was conducted at four hospital transfusion services to test an alternative paradigm of identifying xHEA-typed units for patients in three cohorts by utilizing DNA analysis and a novel inventory management model. STUDY DESIGN AND METHODS: xHEA typing of recipient samples and donor units of known ABO/D status was performed by HEA analysis (BeadChip, BioArray Solutions). xHEA-typed units were assigned to pending transfusion requests using an inventory management system designed to simulate blood order processing. The fraction of requests fulfilled, or "fill fraction" (FF) was determined at four levels of matching stringency. RESULTS: For alloimmunized patients, all but one participating site observed an FF of more than 95% when matching for ABO, D, and known alloantibodies and an FF of more than 90% when additionally matching for C, c, E, e, and K; the site handling the most challenging requests still observed FFs of 62 and 51%, respectively. FF was found to correlate positively with the ratio of available donor units to units requested and negatively with the degree of recipient alloimmunization. CONCLUSION: This study demonstrates that substantial fill fractions can be achieved by selecting existing donor units for xHEA analysis and operating an inventory management system for efficient allocation of units to recipients.

Transfusion and pulmonary morbidity after cardiac surgery.

BACKGROUND: True lung injury is among the leading causes of transfusion-related mortality. Pulmonary morbidity after cardiac surgery has been related to damaging effects of cardiopulmonary bypass and transfusion, but is confounded by cardiac-related events that may not reflect true lung injury. Thus, cardiac surgery poses unique challenges to criteria-specific diagnosis of transfusion-related acute lung injury (TRALI). Our objective was to determine the prevalence of pulmonary morbidity related to transfusion and whether TRALI consensus-criteria are applicable to cardiac surgery. METHODS: A total of 16,847 patients underwent on-pump, coronary artery bypass grafting (CABG), valve, or CABG-valve surgery from September 1998 to February 1, 2006. We performed four propensity-score-matching analyses with logistic regression on probability of receiving a transfusion: total hospital red blood cell (RBC) and fresh frozen plasma (FFP) transfusion and intraoperative RBC and FFP transfusion. Outcomes included traditional cardiac-surgery-defined pulmonary morbidity and ratio of arterial partial pressure of oxygen to fractional inspired oxygen concentration (PaO(2)/FiO(2)), a criterion for TRALI. RESULTS: Patients receiving RBC transfusion had more risk-adjusted pulmonary complications: respiratory distress 4.8% vs 1.5%, p < 0.001; respiratory failure 2.2% vs 0.39%, p < 0.0001; longer intubation times, 9.9 hours vs 7.5 hours, p < 0.0001; acute respiratory distress syndrome, 0.64% vs 0.21%, p = 0.015; and reintubation, 5.6% vs 1.3%, p < 0.0001. The FFP was similarly related to more pulmonary complications after surgery. By TRALI criteria, the majority manifested "lung injury" (PaO(2)/FiO(2) ratio < 300) but unrelated to transfusion (65% vs 64%). CONCLUSIONS: Transfusion is associated with many measures of postoperative pulmonary morbidity. Yet the PaO(2)/FiO(2) ratio as important criterion of TRALI is unrelated to transfusion. Thus, due to the nature of cardiac surgery, application of consensus guided diagnosis of TRALI is problematic.