A randomized controlled pilot study of VO2 max testing: a potential model for measuring relative in vivo efficacy of different red blood cell products.

BACKGROUND: Randomized trials, for example, RECESS, comparing "young" (median, 7-day) versus "middle-aged" (median, 28-day) red blood cells (RBCs), showed no difference in outcome. These data are important; however, they do not inform us about the safety and effectiveness of the oldest RBCs, which some patients receive. It may not be feasible to conduct a clinical trial randomizing patients to receive the oldest blood. Therefore, we propose strenuous exercise (VO2 max testing) as a model to study the relative efficacy to increase oxygen delivery to tissue of different RBC products, for example, extremes of storage duration. STUDY DESIGN AND METHODS: In this pilot study, eight healthy subjects had 2 units of leukoreduced RBCs collected by apheresis in AS-3 using standard methods. Subjects were randomized to receive both (2) units of their autologous RBCs at either 7 or 42 days after blood collection. VO2 max testing on a cycle ergometer was performed 2 days before (Monday) and 2 days after (Friday) the transfusion visit (Wednesday). This design avoids confounding effects on intravascular volume from the 2-unit blood transfusion. The primary outcome was the difference in VO2 max between Friday and Monday (delta VO2 max). RESULTS: VO2 max increased more in the 7-day RBC arm (8.7 ± 6.9% vs. 1.9 ± 6.5%, p = 0.202 for comparison between arms). Exercise duration (seconds) increased in the 7-day RBC arm (8.4 ± 1.7%) but actually decreased in the 42-day arm (-2.6 ± 3.6%, p = 0.002). CONCLUSIONS: This pilot study suggests that VO2 max testing has potential as a rigorous and quantitative in vivo functional assay of RBC function. Our preliminary results suggest that 42-day RBCs are inferior to 7-day RBCs at delivering oxygen to tissues.

No association between donor age and recipient outcomes: transfusion of plasma in patients undergoing coronary artery bypass grafting surgery.

BACKGROUND: Recent animal studies suggest that transfusion of plasma from young donors reverses age-related neurologic and cardiac changes in older recipients. Associations between age of blood product donors and corresponding outcomes in recipients have not been studied in humans. Therefore, our primary objective was to examine this relationship between donor age and recipient outcomes among patients that received plasma during and after coronary artery bypass grafting (CABG) surgery. STUDY DESIGN AND METHODS: This retrospective cohort included patients undergoing CABG surgery who received plasma during or after surgery. All plasma units transfused were evenly divided into tertiles based on the plasma donor age (17-37, 38-50, and 51-86 years), and CABG patients receiving all perioperative plasma within a single donor tertile were studied. Patient demographics and outcomes including mortality, length of stay (LOS), and acute kidney injury (AKI) were measured. RESULTS: Overall, 1306 patients (24% of 5339) received American Red Cross plasma perioperatively, with a median dose of 2 units. In a multivariate model of 1-year mortality, transfusion of a greater number of plasma units (p = 0.0007) and EuroSCORE (p < 0.0001) were significantly associated with patient mortality while donor age was not. There was no difference in mortality between patients receiving plasma from donors in the youngest, middle, or oldest age tertile (10.2 and 8.1% vs. 7.8%, respectively, p = 0.76). Other outcomes, including rates of AKI or LOS, were also independent of plasma donor age. CONCLUSIONS: We did not observe an association between donor age and recipient outcomes among patients who received plasma perioperatively while undergoing CABG surgery.

Randomized study of washing 40- to 42-day-stored red blood cells.

BACKGROUND: Pretransfusion washing of red blood cells (RBCs) stored for a longer duration may have theoretical advantages but few data exist to support this practice. In many hospital settings, use of a point-of-care cell washer could conceivably be used to quickly wash allogeneic RBCs before transfusion. The purpose of this preliminary study was to compare a point-of-care device with a common blood bank device for washing longer-stored RBCs. STUDY DESIGN AND METHODS: Forty RBC units stored for 40 to 42 days were randomized to washing with the COBE 2991 device (Terumo BCT; FDA-cleared for washing stored RBCs) or the Cell Saver Elite (Haemonetics; FDA-cleared point-of-care device for processing and washing fresh autologous shed whole blood). Supernatant and unit RBCs from unwashed (baseline) and washed blood were assayed for potassium, lactate, intracellular ATP, percentage of RBC recovery, cell-free hemoglobin, RBC microparticles, and RBCs were examined for susceptibility to hemolysis by physical stress. RESULTS: Both devices recovered a high percentage of RBCs and efficiently removed extracelluar potassium. Washing with the Elite resulted in significant increases in cell-free Hb, percent hemolysis, and RBC microparticle production, whereas washing with the COBE 2991 did not (fold Δ = 2.1 vs. 1.0, 4.6 vs. 1.2, 2.0 vs. 1.1, respectively; p < 0.05). Hemolysis induced by physical stress was not altered by washing. CONCLUSION: Although point-of-care washing of longer-stored RBCs is appealing, these preliminary data suggest that transfusion of washed, longer-stored units could result in potentially greater exposure to plasma free Hb. More data are needed before this practice can be routinely recommended.

Reduced use of allogeneic platelets through high-yield perioperative autologous plateletpheresis and reinfusion.

BACKGROUND: Intraoperative autologous platelet (PLT) collection as part of a multimodal blood conservation program carries a Class IIa recommendation from the Societies of Thoracic Surgeons and Cardiovascular Anesthesiologists, but achieving a suitable PLT yield limits its application. A novel, autologous, intraoperative, high-yield plateletpheresis collection program was established and retrospectively analyzed to identify potential improvements over previously reported plateletpheresis protocols. STUDY DESIGN AND M-ETHODS: Targeting complex cardiothoracic surgery patients without recent anti-PLT agents, thrombocytopenia, or severe anemia, the program aimed to achieve a PLT yield of at least one standard apheresis unit (3.0 × 10(11) ) within 60 to 90 minutes and using an automated plateletpheresis device (Trima, Terumo BCT). Anesthetized and invasively monitored patients underwent plateletpheresis via a large-bore, indwelling central line placed for the surgery. Collection-related data for quality control purposes and subsequent PLT transfusion requirements were analyzed and reported. RESULTS: Forty-two patients donated autologous PLTs between 2011 and 2012. PLT yield was 4.5 (3.9-5.0) × 10(11) , which significantly exceeds previously reported yields, and procedure duration was 53.2 (48.4-57.9) minutes. As anticipated, postcollection PLT count decreased from 268 (242-293) × 10(9) to 182 (163-201) × 10(9) /L; hypocalcemia was minimized by infusion of 1 g of CaCl2 . Autologous PLT yield was inversely correlated with allogeneic PLT use, and avoidance of allogeneic PLT transfusion was increased when the autologous yield was the equivalent of 2 or more apheresis units. CONCLUSION: High-yield, intraoperative autologous PLT collection is achievable using an automated plateletpheresis device. Initial experience shows a reduction in reliance on allogeneic PLTs for complex cardiothoracic surgery.

Ticlopidine-, clopidogrel-, and prasugrel-associated thrombotic thrombocytopenic purpura: a 20-year review from the Southern Network on Adverse Reactions (SONAR).

Thienopyridine-derivatives (ticlopidine, clopidogrel, and prasugrel) are the primary antiplatelet agents. Thrombotic thrombocytopenic purpura (TTP) is a rare drug-associated syndrome, with the thienopyridines being the most common drugs implicated in this syndrome. We reviewed 20 years of information on clinical, epidemiologic, and laboratory findings for thienopyridine-associated TTP. Four, 11, and 11 cases of thienopyridine-associated TTP were reported in the first year of marketing of ticlopidine (1989), clopidogrel (1998), and prasugrel (2010), respectively. As of 2011, the FDA received reports of 97 ticlopidine-, 197 clopidogrel-, and 14 prasugrel-associated TTP cases. Severe deficiency of ADAMTS-13 (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13) was present in 80% and antibodies to 100% of these TTP patients on ticlopidine, 0% of the patients with clopidogrel-associated TTP (p < 0.05), and an unknown percentage of patients with prasugrel-associated TTP. TTP is associated with use of each of the three thienopyridines, although the mechanistic pathways may differ.

Impact of transfusion of autologous 7- versus 42-day-old AS-3 red blood cells on tissue oxygenation and the microcirculation in healthy volunteers.

BACKGROUND: Stored red blood cells (RBCs) accumulate biochemical and biophysical changes. Maximum storage duration is based on acceptable in vitro characteristics and 24-hour survival, but not RBC function. Relatively little is known about the impact of RBC storage duration on oxygenation and the microcirculation. STUDY DESIGN AND METHODS: Eight healthy subjects donated a double RBC apheresis, which were prestorage leukoreduced and processed in AS-3. Subjects were transfused 1 unit of RBCs at 7 and 42 days after blood collection. Measurements of percentage of tissue oxygenation in the thenar eminence muscle (StO2) and brain (SctO2) were recorded with Food and Drug Administration-cleared noninvasive devices. Sublingual microvascular blood flow (microcirculatory flow index [MFI]) was quantified before and after RBC transfusion using a video microscope. Raw electronic data for all measurements were analyzed by a blinded observer at a core laboratory. RESULTS: The only pre- versus posttransfusion change observed in measurements of SctO2, StO2, or MFI was a very small increase in SctO2, from 70.4 to 71.8 (means, p=0.032) at 7 days. There was no significant difference in the amount of pre-post change at 7 days versus 42 days for any of the measures. CONCLUSION: Transfusion of 1 unit of 42-day-stored RBCs to healthy subjects has no overt detrimental effect on tissue oxygenation or the microcirculation assessed by clinically available monitors.

A clinical prediction tool to estimate the number of units of red blood cells needed in primary elective coronary artery bypass surgery.

BACKGROUND: Red blood cell (RBC) transfusion is common during cardiac surgical procedures. Empiric crossmatching, without attempting to estimate individual transfusion requirements is typical. We hypothesized that a clinical prediction tool could be developed to estimate the number of units of RBCs needed for coronary artery bypass grafting (CABG) surgery. STUDY DESIGN AND METHODS: With institutional review board approval, detailed demographic, risk factor, and transfusion data of primary elective CABG procedures (n=5887) from September 1, 1993, to June 20, 2002, were studied and the data set was divided into development and validation subgroups. Multivariable ordinal logistic regression was used to develop and validate transfusion risk factors, assign them a relative weight, and create a model to stratify patients into groups depending on predicted need for 0, 2, 4, or more than 4 RBC units. The model was compared with current standard practice of crossmatching 4 RBC units in terms of observed blood product usage over the study period. RESULTS: Demographic and transfusion risk factor variables in the development (n=3876) and validation (n=2011) data sets were similar. The predictive value of the model was good for the development and validation groups, with a c-index of 0.79 and 0.78, respectively. Applying the predictive model reduced the number of crossmatches by 30% without underproviding RBC units and increased the percentage of patients crossmatched exactly for the required number of units from 11% to 21%. CONCLUSIONS: Predictive factors for RBC transfusion were identified and used to construct a clinical tool to conserve blood bank resources without increasing patient risk.

Guidelines on the use of therapeutic apheresis in clinical practice--evidence-based approach from the Apheresis Applications Committee of the American Society for Apheresis.

The American Society for Apheresis (ASFA) Apheresis Applications Committee is charged with a review and categorization of indications for therapeutic apheresis. Beginning with the 2007 ASFA Special Issue (fourth edition), the subcommittee has incorporated systematic review and evidence-based approach in the grading and categorization of indications. This Fifth ASFA Special Issue has further improved the process of using evidence-based medicine in the recommendations by refining the category definitions and by adding a grade of recommendation based on widely accepted GRADE system. The concept of a fact sheet was introduced in the Fourth edition and is only slightly modified in this current edition. The fact sheet succinctly summarizes the evidence for the use of therapeutic apheresis. The article consists of 59 fact sheets devoted to each disease entity currently categorized by the ASFA as category I through III. Category IV indications are also listed.

Management of Blood Product Market Withdrawals - A Single Institution's Process and Experience.

OBJECTIVE: While lookback investigations follow specific Food and Drug Administration (FDA) requirements, the management of blood product market withdrawals from suppliers varies widely. Follow-up data are limited, prompting this analysis of the types and reasons for recipient notification and their outcomes. METHODS: A single institution retrospective review of market withdrawal and lookback files from 2012-2015 included product type, reason, FDA category, notification, and turnaround time. Descriptive statistics and chi-square analysis were performed. RESULTS: Over 4 years, 796/229,549 (0.35%) blood components were implicated in supplier notifications, including market withdrawals (84.3%) and lookbacks (15.7%). Seventy-nine cases resulted in patient notification. 97% of patient notifications were achieved within 3 months. Plasma with human leukocyte antigen antibodies was the most common reason for withdrawal (20.5%). Category 1 notifications were the most commonly reported by this transfusion service, apart from in 2015 when category 4 notifications were highest. Over four years, the proportion of notifications by category remained relatively stable. CONCLUSIONS: Market withdrawal investigations involve significant effort to review, document, and appropriately notify. Standardized management and centralized reporting of recipient notification of market withdrawals may improve this process.

Ticlopidine- and clopidogrel-associated thrombotic thrombocytopenic purpura (TTP): review of clinical, laboratory, epidemiological, and pharmacovigilance findings (1989-2008).

Thrombotic thrombocytopenic purpura (TTP) is a fulminant disease characterized by platelet aggregates, thrombocytopenia, renal insufficiency, neurologic changes, and mechanical injury to erythrocytes. Most idiopathic cases of TTP are characterized by a deficiency of ADAMTS13 (a disintegrin and metalloprotease, with thrombospondin-1-like domains) metalloprotease activity. Ironically, use of anti-platelet agents, the thienopyridine derivates clopidogrel and ticlopidine, is associated with drug induced TTP. Data were abstracted from a systematic review of English-language literature for thienopyridine-associated TTP identified in MEDLINE, EMBASE, the public website of the Food and Drug Administration, and abstracts from national scientific conferences from 1991 to April 2008. Ticlopidine and clopidogrel are the two most common drugs associated with TTP in FDA safety databases. Epidemiological studies identify recent initiation of anti-platelet agents as the most common risk factor associated with risks of developing TTP. Laboratory studies indicate that most cases of thienopyridine-associated TTP involve an antibody to ADAMTS13 metalloprotease, present with severe thrombocytopenia, and respond to therapeutic plasma exchange (TPE); a minority of thienopyridine-associated TTP presents with severe renal insufficiency, involves direct endothelial cell damage, and is less responsive to TPE. The evaluation of this potentially fatal drug toxicity can serve as a template for future efforts to comprehensively characterize other severe adverse drug reactions.

A prospective, double-blind, randomized clinical feasibility trial of controlling the storage age of red blood cells for transfusion in cardiac surgical patients.

BACKGROUND: Recent evidence demonstrates an association between duration of storage of red blood cells (RBC) and morbidity and mortality after cardiac surgery. We studied the feasibility of two different schemes for categorizing and randomizing age of RBC units transfused in cardiac surgical patients. STUDY DESIGN AND METHODS: In Phase 1, 20 subjects were randomly assigned to standard of care (SOC) versus no RBCs with more than 21 days' storage duration. In Phase 2, 23 subjects were randomized to RBCs of 7 +/- 4 versus 21 +/- 4 days' storage duration. The age of study RBC units was masked. RESULTS: In Phase 1, no patients received RBCs 31 days or older in SOC, and there was overlap in storage age shared in both arms so the predefined feasibility criteria were not met. In Phase 2, it was feasible to deliver specified age RBCs to the 7-day arm (achieved in 100% of subjects), but feasibility was not demonstrated for the 21-day arm (only 50% of subjects transfused with target age RBCs). Significant differences, however, were observed between the 7 +/- 4- and 21 +/- 4-day arms with respect to age of all RBC units (6 +/- 2 vs. 18 +/- 7, p = 0.0002) and maximum age (7 +/- 2 vs. 20 +/- 7, p < 0.0001). CONCLUSION: Given the current storage age distribution of available RBC inventory, use of a SOC arm in future studies is unlikely to result in a large exposure to "old" blood. It is feasible to randomize patients to "younger" RBCs (3-11 days) but design strategies are needed to provide "intermediate-aged" or "old" blood as a comparator.

Update on multi-center clinical trials in the United States.

This article reviews numerous multi-center clinical trials, either ongoing or in planning stages, which involve diverse clinical applications and emerging technologies in apheresis and transfusion medicine. The investigations summarized herein involve the following specific areas: platelet dosing strategy, thrombotic thrombocytopenia purpura, inflammatory bowel disease, seven-day platelet storage, dendritic cell vaccines, and age-related macular degeneration.

Patterns of platelet response in idiopathic TTP/HUS: frequency of declining platelet counts with plasma exchange and the recognition and significance of a pseudo refractory state.

For thrombotic thrombocytopenic purpura (TTP), daily plasma exchange (TPE) is typically discontinued when the platelet count normalizes (>150 x 10(9)/L). We observed a decline in platelet count during TPE and in patients who appeared pseudo-refractory because of a platelet count plateau (100-150 10(9)/L range). In the present study, we evaluated platelet count trends in TTP patients. Retrospective review of TTP patients from 01/1999 to 12/2004 was completed. Patients were categorized based on platelet count trends: Group I, counts rose then decreased to levels <100 x 10(9)/L; Group II, counts declined following TPE initiation; Group III, counts rose continuously; Group IV, counts decreased after the count was >100 x 10(9)/L. Additionally, we identified pseudo-refractory patients caused by a platelet count plateau (>100 x 10(9)/L but <150 x 10(9)/L). We identified 60 TTP patients. Within Group I (17 patients/17 series/19.1% of total), the mean decrease in platelet count was 67.3% +/- 22.1% following initial rise. Within Group II (24 patients/25 series/28.1% of total), the mean decrease was 28% +/- 5.3% following presentation. Group III included 31 patients/39 series (43.8% of the total). Within Group IV (seven patients/eight series/9.0% of total), the mean decrease was 17.4% +/- 12.6% following a sustained rise >100 x 10(9)/L. With a declining platelet count and daily TPE, it is generally sufficient to stay the course and the decline will reverse. Our limited experience with pseudo-refractory patients supports discontinuing TPE when counts plateau between 100 and 150 x 10(9)/L when a therapy goal is a platelet count of 150 x 10(9)/L. Recognition of this pseudo-refractory state can minimize the risks of prolonged TPE and the risks of adjunct interventions.

Clopidogrel-associated TTP: an update of pharmacovigilance efforts conducted by independent researchers, pharmaceutical suppliers, and the Food and Drug Administration.

BACKGROUND AND PURPOSE: Since the 1999 identification of clopidogrel-associated thrombotic thrombocytopenic purpura (TTP) through independent active surveillance, subsequent cases have been identified by pharmaceutical suppliers of clopidogrel and the Food and Drug Administration (FDA). For cases of clopidogrel-associated TTP reported between 1998 to 2002, we evaluated the quality and timeliness of data from 3 reporting systems-independent active surveillance (n=13), pharmaceutical suppliers (n=24), and the FDA (n=13)-and identified prognostic factors associated with mortality. METHODS: This study assessed the completeness of information on TTP diagnosis, treatment response, and causality from the 3 reporting systems. In addition, predictors of mortality were identified through classification tree analysis. RESULTS: Completeness, timeliness, and certainty of diagnosis were best for cases obtained by active surveillance, intermediate for cases reported to the pharmaceutical supplier, and poorest for cases reported directly to the FDA. Clopidogrel had been used for

A large university medical center delivery system for therapeutic apheresis services.

The clinical applications of therapeutic apheresis (TA) encompass a broad spectrum. Diversity exists not only in the age and acuity of patients treated, but also in the range of therapeutic approaches and technology. Particularly over the past decade, there has been rapid expansion of TA for primary, adjuvant, and empiric therapies for myriad clinical settings. Recognizing this context, it is not surprising that a variety of delivery models for providing TA services have emerged. In this paper, the structure of an apheresis service at a large academic university hospital will be described to illustrate one example of an effective apheresis delivery model. Alternatives to this delivery model are certainly possible. The discussion will also indicate where some organizational variations may occur within this category of facility.

Feeding practices and other risk factors for developing transfusion-associated necrotizing enterocolitis.

AIMS: The objective of this study is to determine the incidence of and risk factors for necrotizing enterocolitis (NEC) and transfusion-associated NEC (TANEC) in very-low-birth-weight (VLBW) infants pre/post implementation of a peri-transfusion feeding protocol. STUDY DESIGN: A retrospective cohort study was conducted including all inborn VLBW infants admitted to the Duke intensive care nursery from 2002 to 2010. We defined NEC using Bell's modified criteria IIA and higher and TANEC as NEC occurring within 48h of a packed red blood cell (pRBC) transfusion. We compared demographic and laboratory data for TANEC vs. other NEC infants and the incidence of TANEC pre/post implementation of our peri-transfusion feeding protocol. We also assessed the relationship between pre-transfusion hematocrit and pRBC unit age with TANEC. RESULTS: A total of 148/1380 (10.7%) infants developed NEC. Incidence of NEC decreased after initiating our peri-transfusion feeding protocol: 126/939 (12%) to 22/293 (7%), P=0.01. The proportion of TANEC did not change: 51/126 (41%) vs. 9/22 (41%), P>0.99. TANEC infants were smaller, more likely to develop surgical NEC, and had lower mean pre-transfusion hematocrits prior to their TANEC transfusions compared with all other transfusions before their NEC episode: 28% vs. 33%, P<0.001. Risk of TANEC was inversely related to pre-transfusion hematocrit: odds ratio 0.87 (0.79-0.95). CONCLUSIONS: Pre-transfusion hematocrit is inversely related to risk of TANEC, which suggests that temporally maintaining a higher baseline hemoglobin in infants most at risk of NEC may be protective. The lack of difference in TANEC pre-/post-implementation of our peri-transfusion feeding protocol, despite an overall temporal decrease in NEC, suggests that other unmeasured interventions may account for the observed decreased incidence of NEC.

Many, but not all, outcome studies support exclusion of female plasma from the blood supply.

Transfusion-related acute lung injury (TRALI) has been identified as the most common cause of transfusion-related death. Although extensive literature supports restrictions on female-donor plasma to reduce antibody-mediated TRALI, only a few outcome studies have assessed for effects of this change, and some, but not all, have endorsed the policy. A recent report even suggests poorer outcomes in cardiac surgery patients with a shift to male-donor-only plasma, raising concerns that TRALI alone, whether catastrophic or more survivable, is insufficient compared with broader measures, such as short-term mortality or long-term survival, as an end point to assess for overall improvements in patient care.