Evaluation of the red cell storage lesion after irradiation in filtered packed red cell units

Packed red cell units (n = 10) were filtered and divided equally. One-half unit from each donor was irradiated (x) (3500 cGy). On Days 0, 14, 28, and 42, ATP, K+, Na+, lactate dehydrogenase (LDH), plasma-free hemoglobin (PFH), and pH were determined. The reduction in ATP was greater in the irradiated than the nonirradiated (y) units by Day 42 (mean x-y: -70, p = 0.0005). The increase in K+ was greater in the irradiated than nonirradiated units on Days 14, 28, and 42 (mean x-y: 17-20, p = 0.0001). Decrease in pH and increases in LDH and PFH were significant (p less than 0.05) on Day 42 only. K+ increases added only 1.7 to 2.0 mmol per unit, a difference felt to be clinically insignificant. The changes noted in ATP, pH, LDH, and PFH are significant but minimal on Day 42 and imply that viability changes would also be minimal. These biochemical data support the storage of irradiated units for at least 28 days.     

Preparation of packed red blood cell units in the blood bank: Alteration in red blood cell deformability

BackgroundDonated blood is stored in the blood bank as packed red blood cell units. In the process of packed cells preparation, the red blood cells (RBCs) are subjectedto high level of shear stress, which can induce alterations in their properties.In the present study, we examined the effect of packed RBCs preparation (which included leuko-filtration) on red cell deformability.MethodsBlood samples were collected from 25 healthy donors and from corresponding units of packed RBCs. The portion of undeformable cells (%UDFC) was determined for each sample.ResultsThe median value of %UDFC was equal to 6.75 ± 0.70 %, for freshly-donated RBCs, and to 6.36 ± 0.51 %, for packed cells. Wherein, %UDFC may increase or decrease following packed cells preparation, depending upon the initial portion of undeformable cells.ConclusionLikely, exposure of RBCs to high shear stress, during packed cells preparation, induces opposing effects: (a) removal/destruction of rigid (undeformable) cells, thereby reducing their total amount (i.e., decreasing the %UDFC) on the one hand, and (b) mechanical damage to the cell membrane and subsequent reduction of the cell deformability (thereby increasing the %UDFC) on the other. As a consequence, the final impact of packed cells preparation is primarily determined by the initial state of erythrocytes in the blood of the donor.     

Chemokine receptors expressed on T cells in packed red blood cell units change over storage time

The transfusion of blood products is associated with adverse events that are related to the leukocytes in stored units of blood. These leukocytes have been shown to promote the elaboration of inflammatory cytokines. However, the status of a set of key inflammatory mediators, chemokine receptors, expressed on T lymphocytes in stored red blood cell (RBC) units is largely unknown. We investigated the expression pattern of selected chemokine receptors on T cells from non-leukocyte-reduced RBC units over storage time. Selecting segments from stored RBC units, we evaluated the T-cell subsets for the chemokine receptors CXCR3 and CCR4 by flow cytometry. Statistical analysis was performed by regression analysis. We analysed 30 samples stored between 5 and 38 days. The CD4+ T cells expressing CXCR3 increased by 0.27% daily (P= 0.02), whereas the expression of CCR4 declined by 0.40% daily (P < 0.001). Though the expression of the chemokine receptors on CD8+ cells followed the same trend, the changes were statistically nonsignificant. This study suggests that a longer duration of storage is associated with a higher expression of chemokine receptor CXCR3 and a lower expression of CCR4 on T cells in RBC units, suggesting a pro-inflammatory Th1 bias. The clinical significance of these changes in the setting of adverse transfusion events needs further evaluation.     

Relationship between packed cell volume, platelets, and platelet survival in red blood cell-hypertransfused mice.

In this study we have measured platelet and megakaryocyte concentration, blood volume, and platelet survival of mice after RBC hypertransfusion to PCVs of 62% to 90%. The platelet concentration of mice with PCVs up to 75% was decreased by up to one half. At higher PCVs a more severe thrombocytopenia developed, with platelet concentrations decreased to less than 10% of baseline in approximately one half of the mice. Blood volumes of the hypertransfused mice were increased up to twofold. Megakaryocyte concentrations were normal or increased. Platelet survival in mice with PCVs less than 75% was normal but was sharply decreased for mice with higher PCVs. The decrease in platelet concentration at moderately elevated PCVs may be explained by hemodilution in the larger blood volume. However, hemodilution alone cannot explain the severe thrombocytopenia at higher PCVs. The presence of decreased platelet survival with normal or increased megakaryocyte concentrations in this latter group suggests that the severe thrombocytopenia is the result of more rapid platelet destruction. In summary, elevation of the PCV by RBC hypertransfusion produces thrombocytopenia. The severity of the thrombocytopenia and the mechanisms involved in producing it change abruptly when the PCV exceeds 75%. These findings should be considered in interpretations of the influence of RBC hypertransfusion on hematopoiesis and in clinical and experimental studies of thrombopoiesis in polycythemic subjects.     

Neutrophil priming, caused by cell membranes and microvesicles in packed red blood cell units, is abrogated by leukocyte depletion at collection.

BACKGROUND AND OBJECTS: Lipids with platelet activating factor (PAF)-like activity in supernatant of packed red blood cells (PRBC) cause priming of the neutrophil respiratory burst. This effect increases with length of storage. Washing of PRBC has been considered as a means to eliminate this effect; however, the role of the cellular component was not evaluated independently of the supernatant. The source of the inflammatory lipids of the supernatant is likely to be cell membranes altered during ageing in storage and therefore, washing will not eliminate neutrophil priming caused by transfusion of aged PRBC units. The ability of washed PRBC to prime mononuclear cells for another known effect of PAF, the production of IL-8, and the probability that this lipid activity is present on microparticles in PRBC supernatant were also investigated. MATERIALS AND METHODS: At collection 10 units of whole blood were split into two equal aliquots one filtered and one unfiltered. PRBC were prepared and stored at 4 degrees C in CPD-AS5. Each week, fresh neutrophils were incubated with samples of washed PRBC and fixed. Change in CD11b, a marker known to increase on the surface of primed neutrophils, was determined by flow cytometry. To determine whether neutrophil priming ability of PRBC supernatant is contained on microvesicles, centrifuged and uncentrifuged supernatant samples were incubated with fresh neutrophils and change in CD11b expression was determined. Plasma IL-8 levels were also measured after exposure of monocytes from fresh whole blood to filtered and unfiltered washed PRBC with and without the addition of fMLP. RESULTS: Washed PRBC caused a 50-116% increase in CD11b neutrophil surface expression over baseline expression. Filtration of whole blood at collection reduced this CD11b up-regulation by 25-34%. Reduction of priming ability by filtration began on the day of collection and persisted for the storage life of the units. Centrifugation resulted in a reduction of CD11b up-regulation of 11-28% compared with unspun supernatant. Incubation of unfiltered PRBC resulted in priming of mononuclear leukocytes for IL-8 production with a 73-109% increase over baseline, but no increase over baseline was seen for incubation with filtered blood. CONCLUSION: Washing does not eliminate the ability of PRBC units to prime neutrophils and mononuclear cells, because the cellular component of PRBC, in addition to the supernatant, induces priming. Leukodepletion filters significantly reduce these effects compared with unfiltered PRBC. The in vitro beneficial effect of filtration lasts for the shelf life of 42 day units. The ability of PRBC supernatant to prime neutrophils is present on microvesicles.     

White cell subsets in apheresis and filtered platelet concentrates

BACKGROUND: White cell (WBC)-reduced platelet concentrates (PCs) are defined by their absolute WBC count, a criterion which provides no information regarding the various WBC subsets contained in the PC. These heterogeneous cells are known to mediate different physiologic and pathophysiologic functions and account for distinct adverse transfusion responses. This study describes a method which allows the detection and quantification of these subsets and characterizes their presence in a variety of platelet components. STUDY DESIGN AND METHODS: Random-donor pooled PCs (RD PCs) and single-donor apheresis PCs (SD PCs) were studied. RD PCs consisting of 6 units of 2- to 3-day old PCs were randomly assigned to be filtered with one of four WBC-reduction filters from three different manufacturers (n=34). The residual WBCs were pelleted by centrifugation and isolated on a density gradient. The various WBC subsets were quantified by flow cytometry in unfiltered and filtered PCs using fluorescence and two-angle light scatter. SD PCs obtained with two manufacturer's systems and three processing protocols (n=30) were studied in like manner. RESULTS: WBC counts for non-WBC- reduced PCs averaged 3 × 10(8) in RD PCs and ranged from 8.6 to 9.6 × 10(6) per SD PC. Residual WBC counts in filtered PCs ranged from 2.3 × 10(4) to 2.2 × 10(5) and those in WBC-reduced SD PCs averaged 2.2 × 10(5) per unit. The data demonstrate significant phenotypic differences among PCs produced with various procedures. All SD PCs and two of four filtered RD PCs contained five WBC populations including granulocytes and monocytes, while RD PCs filtered with the remaining manufacturer's devices contained only lymphocytes. CONCLUSION: The data confirm that distinct phenotypic differences exist among PCs prepared with different devices and/or procedures. It is suggested that as for non-generic pharmaceuticals, the clinical benefits of these various PCs should be individually proved.     

A comparison of resuscitation with packed red blood cells and whole blood following hemorrhagic shock in canines

Resuscitation with crystalloid and packed red blood cells has for the most part replaced the use of plasma and whole blood in the initial treatment of hemorrhagic shock. The effects of such changes on cardiovascular function following hemorrhagic shock remain largely unexplored. We examined cardiovascular function in anesthetized canines subjected to severe hemorrhagic shock. Mongrel canines of either gender were anesthetized with isoflurane and instrumented for measurement of arterial pressure, cardiac output, coronary flow, and left ventricular pressure and volume for the determination of end systolic elastance (Ees). Following a 30-min stabilization period, blood was rapidly removed to induce fixed pressure (mean arterial pressure = 35 mmHg) hemorrhagic shock for 90 min or until an arterial lactate of 7.0 mM was achieved. Animals were then resuscitated with 2/3 of the shed volume as lactated Ringer's and an equal volume of either whole blood (WB, n = 8) or packed red blood cells (PRBC, n = 10) resuspended in lactated Ringer's (LR) solution to replace expressed plasma volume. PRBC resuscitated dogs showed lower values of mean arterial pressure, cardiac output, rates of ventricular contraction and relaxation and myocardial work. Increasing the maintenance infusion rate of LR (10 mL/kg/h) following PRBC infusion normalized mean arterial pressure, but not other indices of cardiovascular function. Thus, WB, but not PRBC resuscitation restores normal myocardial function during resuscitation from severe hemorrhagic shock.     

Risks of packed red blood cell transfusion in patients undergoing cardiac surgery

Packed red blood cell (PRBC) transfusion is common in patients undergoing cardiac surgery. Evidence has accumulated demonstrating that such patients can tolerate relatively low hemoglobins, and an extensive body of literature has developed demonstrating that patients undergoing such surgery who receive PRBC are at risk for several adverse outcomes including increased mortality, atrial fibrillation, and more postoperative infections, as well as numerous other complications. The PubMed database was searched for the English language literature on the topic of PRBC transfusion and outcomes in patients undergoing cardiac surgery, as well as alternatives to this intervention. Data were reviewed to assess the impact of transfusion in patients undergoing cardiac surgery on mortality, cardiac, infectious, and pulmonary, as well as a variety of miscellaneous complications. Patients receiving PRBC were consistently identified as being at higher risk for complications in all categories. The limited prospective data were consistent with the retrospective data, which comprised most of the literature. The preponderance of the literature suggests that patients undergoing cardiac surgery can tolerate lower hemoglobin/hematocrit values than traditionally appreciated. Most published data also indicate that PRBC transfusion should be reserved for patients with an identifiable clinical/physiologic indication fir this intervention, consistent with recent specialty society guidelines.     

Evaluation of dosed red blood cell units collected with Gambro BCT--TRIMA.

The increasing need of collecting high quality blood components and of improving the overall productivity of a blood centre requires the utilisation of a new innovative process that combines high speed collection with an automated process and blood component tailoring to fit individual patient requirements. We collected dosed Red Blood Cell (dRBC) units on 64 donors, eligible as regular donors on the Gambro BCT TRIMA using the dRBC collection protocol. The collection target was set to 180 ml packed Red Blood Cells (pRBCs) in 225 ml total collection volume (n = 7), or 300 ml pRBCs in 375 ml total collection volume (n = 33) or 360 ml in 450 ml (n = 24), depending on donor's hematological profile and blood volemia. Saline was infused as the replacement fluid at a 120%) collection:infusion ratio. Donor per cent hematocrit was (mean +/- S.D.) 43.7 +/- 4.0% and TBV = 4.99 +/- 0.69 1. The procedures yielded 100 +/- 6% of predicted yield, with a hematocrit of 78.2 +/- 6.6% in 29 +/- 3 min. Hb content was 99.9 +/- 21.8 in all procedures, or 61.5-94.4-118.6 g in the three groups, respectively. After the addition of the SAG-M storage solution, the hematocrit was 56.3 +/- 6.2%. No adverse reactions have been reported by the donors and all pPRBC units were transfused to patients without any transfusion reaction being reported by clinicians. The dRBC protocol is well tolerated by donors without any side effects, other than normal effects of regular blood donation. Higher pRBC productivity can be reached with a safe and automated process in conjunction with a high and consistent product quality easily matching the donor collection criteria and pRBC unit standards. Tailoring of pRBC units can result in an improved patient transfusion support.     

Audit of the use of packed red blood cells in association with seven common surgical procedures

The risks and costs associated with the transfusion of blood and its components have led to increasing demands for evidence of the appropriate use of blood components. We have examined the use of packed red blood cells (PRBC) in association with seven common, surgical procedures performed in 1987 and 1988 to establish patterns of use. The information has formed the basis for surgical blood order schedules and autologous donation targets for these procedures. It has also been used to determine appropriate audit 'triggers' and the results of an audit using these 'triggers' are reported.     

孕妇外周血中胎儿有核红细胞数量与胎儿窘迫的关系

目的:探讨孕妇外周血中胎儿有核红细胞(nucleatedredbloodcells,NRBC)数与胎儿窘迫的关系。方法:对54名孕龄32～42周,年龄19～35岁(包括19名急性胎儿窘迫,15名慢性胎儿窘迫)的孕妇外周血进行不连续密度梯度离心,对分离后的细胞进行制片、染色,显微镜下进行NRBC计数,比较组间差异。结果:15名慢性胎儿窘迫孕妇外周血中NRBC数目为(23.26±6.75)个/7mL;同孕龄正常妊娠妇女外周血中NRBC数目为(9.43±4.01)个/7mL,两者间差异有显著性(P<0.05)。19名急性胎儿窘迫孕妇外周血中NRBC数目为(10.87±4.29)个/7mL,与正常妊娠间差异无显著性(P>0.05)。结论:慢性胎儿窘迫孕妇外周血中NRBC数目明显升高,为胎儿窘迫的临床预测和评估提供了一条新思路。     

A new tool in white blood cell reduction for packed red cells:5 Log depletion

The recent development of new filters used for leucocyte reduction aims at restricting the number of leucocytes to a threshold where their undesirable effects can be minimized or excluded. In this paper we describe the performance of a new filter named BIO R01 MAX and claimed by the manufacturer to perform 5 Log₁₀ depletion. The results show that the efficiency of the filter reached 5 Log₁₀ depletion and the absolute number of white blood cells in the post-filtration units is always less than 2 × 10₄ with considerable safety in the prevention of transfusion reactions.     

Understanding the demand for phenotyped red blood cell units and requests to perform molecular red blood cell typing for Australian patients

BackgroundAustralian Red Cross Lifeblood has seen a 50 % increase in demand for phenotyped red blood cell (RBC) units between 2016–2018 and a 30 % increase in demand in 2018 to perform molecular RBC typing on patient samples. Lifeblood conducted a survey to understand transfusion laboratory practices for requesting patient phenotyping and/or molecular RBC typing and for selecting phenotyped RBC units in various patient groups.Study design and methodsAn electronic Qualtrics survey form was sent to 296 transfusion laboratories with questions designed to understand the practice of selecting phenotyped RBC units and reasons for requesting extended serology or molecular RBC typing.Results49 (16.6 %) transfusion laboratories provided data. Reasons to request extended phenotyping and/or molecular RBC typing for patients included; chronic transfusion (n = 31 laboratories), sickle cell disease (n = 25), Thalassemia (n = 23), requirement for anti-CD38 or other MAB therapy (n = 23) or Myelodysplasia (n = 22). Forty-seven transfusion laboratories provided responses with reasons for requesting molecular RBC typing which included: predicting phenotype in patients with multiple antibodies (n = 31), prior to administering anti-CD38 or other MAB therapies (n = 29), for pregnancy related transfusions (n = 28) or for confirming the phenotype of recently transfused patients (n = 18).ConclusionTransfusion laboratory practices indicated that phenotyped RBC units were selected for patients requiring chronic transfusion support and/or undergoing MAB therapy. Requests for molecular RBC typing occurred for more complex patient requirements where serological investigations were not suitable or possible due to reagent restrictions.     

CFU-GM and T cell subsets in young red cell collections

Young red cells (YRBCs) prepared using cell separators contain large numbers of white cells. The absolute numbers and percentages of different lymphocyte subsets and progenitor cells in YRBC collections were assessed before and after filtration through two white cell filters. It was found that the filters do not take up or selectively allow through any one lymphocyte subset and that the absolute number of T cells and progenitor cells in YRBC collections after filtration is less than that in normal donor blood.     

红细胞膜表面黏附分子与红细胞寿命的相关性研究

目的 探讨红细胞寿命与其膜表面蛋白黏附分子的关系,以期建立1种检测红细胞贮存时间的方法 .方法 采集10人(份)健康无偿献血者的新鲜红细胞标本10 ml/份,应用Percoll密度梯度离心法将红细胞分成5个年龄(层),流式检测术检测各分层红细胞膜表面黏附分子CD47、CD44、CD147的表达量;应用SPSS统计软件对...     

Visual assessment of hemolysis in red blood cell units and segments can be deceptive

BACKGROUND: Blood components that appear hemolyzed are discarded. However, visual inspection is subjective and criteria for excessive hemolysis are poorly defined. STUDY DESIGN AND METHODS: Packed RBCs (10 CPDA-1, 10 Adsol) were collected. Half of each unit was leukoreduced. Plasma Hb was measured and compared in segments and units by three methods: 1) a HemoCue Plasma/Low Hb Photometer system; 2) a tetramethyl-benzidine (TMB) chemical method, and 3) a free Hb visual comparator. RESULTS: Visual assessment tended to overestimate hemolysis. Chemical methods were comparable (r(2)= 0.894; HemoCue = 0.043 +[0.770]x TMB; n = 400; range, 0.01-0.5 g/dL), although the mean plasma Hb (g/dL) for the HemoCue method was higher than that of the TMB method (0.12 vs. 0.10 g/dL, respectively; p < 0.001). No units would have been discarded based on a hemolysis level of at least 0.6 g/dL (approx. 1%) if measured by a chemical method. However, 50 percent of CPDA-1 and 10 percent of Adsol units would have been discarded if only visual criteria were used. Leukoreduction did not increase plasma Hb levels. Discrepancies in plasma Hb levels were noted between units and their corresponding segments. CONCLUSION: Visual assessment of hemolysis can result in unnecessary wastage of blood components. HemoCue offers an alternative, objective method to assess plasma Hb in the setting of blood collection and processing facilities for routine quality control and process validation, and may aid in the development of objective criteria for excessive hemolysis in blood components.