Leucocyte depletion of blood components

Review of anesthesia in liver transplantation

Liver transplantation (LT) is a well-accepted treatment modality of many end-stage liver diseases. The main issue in LT is the shortage of deceased donors to accommodate the needs of patients waiting for such transplants. Live donors have tremendously increased the pool of available liver grafts, especially in countries where deceased donors are not common. The main ethical concern of this procedure is the safety of healthy donors, who undergo a major abdominal surgery not for their own health, but to help cure others. The first part of the review concentrates on live donor selection, preanesthetic evaluation, and intraoperative anesthetic care for living liver donors. The second part reviews patient evaluation, intraoperative anesthesia monitoring, and fluid management of the recipient. This review provides up-to-date information to help improve the quality of anesthesia, and contribute to the success of LT and increase the long-term survival of the recipients.

The involvement of cation leaks in the storage lesion of red blood cells

Stored blood components are a critical life-saving tool provided to patients by health services worldwide. Red cells may be stored for up to 42 days, allowing for efficient blood bank inventory management, but with prolonged storage comes an unwanted side-effect known as the "storage lesion", which has been implicated in poorer patient outcomes. This lesion is comprised of a number of processes that are inter-dependent. Metabolic changes include a reduction in glycolysis and ATP production after the first week of storage. This leads to an accumulation of lactate and drop in pH. Longer term damage may be done by the consequent reduction in anti-oxidant enzymes, which contributes to protein and lipid oxidation via reactive oxygen species. The oxidative damage to the cytoskeleton and membrane is involved in increased vesiculation and loss of cation gradients across the membrane. The irreversible damage caused by extensive membrane loss via vesiculation alongside dehydration is likely to result in immediate splenic sequestration of these dense, spherocytic cells. Although often overlooked in the literature, the loss of the cation gradient in stored cells will be considered in more depth in this review as well as the possible effects it may have on other elements of the storage lesion. It has now become clear that blood donors can exhibit quite large variations in the properties of their red cells, including microvesicle production and the rate of cation leak. The implications for the quality of stored red cells from such donors is discussed.

Effects of blood products on nosocomial infections in liver transplant recipients

OBJECTIVES

Infection is the most severe complication after an organ transplant. Blood cell transfusion is an independent risk factor for adverse events, including infection in the recipient. This study sought to evaluate the effect of blood product transfusions on nosocomial infections in liver transplant patients.

MATERIALS AND METHODS

Patients who underwent a liver transplant at our hospital between 2003 and 2010 were recruited for this study. Exclusion criteria were incomplete records, patients who were hospitalized for more than 48 hours during the 4 weeks before transplant, and pediatric transplants. Incidence of nosocomial infections, which were defined as infections occurring within 30 days after transplant was the primary endpoint.

RESULTS

The incidence of nosocomial infections was 28.7%. The number of transfusions of packed red blood cells and fresh frozen plasma was significantly higher in patients with nosocomial infection compared with patients without nosocomial infection (P = .018 and P = .039). Blood products dose-dependently contributed to nosocomial infections. Transfusions of ≥ 7.5 units of red blood cells (odds ratio: 2.8) or ≥ 12.5 units of fresh frozen plasma (odds ratio: 3.27) were associated with nosocomial infections (P = .042 and P = .015). The infection-related mortality rate was 10.3%.

CONCLUSIONS

Blood product transfusions are associated with an increased rate of nosocomial infections, which contributes to higher morbidity and mortality.

Historical perspective and future directions in platelet research

Platelets are a remarkable mammalian adaptation that are required for human survival by virtue of their ability to prevent and arrest bleeding. Ironically, however, in the past century, the platelets' hemostatic activity became maladaptive for the increasingly large percentage of individuals who develop age-dependent progressive atherosclerosis. As a result, platelets also make a major contribution to ischemic thrombotic vascular disease, the leading cause of death worldwide. In this brief review, I provide historical descriptions of a highly selected group of topics to provide a framework for understanding our current knowledge and the trends that are likely to continue into the future of platelet research. For convenience, I separate the eras of platelet research into the "Descriptive Period" extending from ~1880-1960 and the "Mechanistic Period" encompassing the past ~50 years since 1960. We currently are reaching yet another inflection point, as there is a major shift from a focus on traditional biochemistry and cell and molecular biology to an era of single molecule biophysics, single cell biology, single cell molecular biology, structural biology, computational simulations, and the high-throughput, data-dense techniques collectively named with the "omics postfix". Given the progress made in understanding, diagnosing, and treating many rare and common platelet disorders during the past 50 years, I think it appropriate to consider it a Golden Age of Platelet Research and to recognize all of the investigators who have made important contributions to this remarkable achievement..

Use of leukoreduced blood does not reduce infection, organ failure, or mortality following trauma

Background

Leukoreduced (LR) blood has been demonstrated to reduce morbidity and mortality in high-risk surgical patients, but not in trauma patients. The objective of the present study was to determine the effect of LR blood on morbidity and mortality. We hypothesized that the use of LR blood does not improve outcome in trauma patients.

Methods

This study was a retrospective cohort analysis of trauma patients transfused at a level 1 Trauma Center from 2001 to 2004. Between 2002 and 2003, LR blood was transfused. Prior to that time and subsequent to it, non-leukoreduced (NLR) blood was transfused. This created two historical comparison groups. Data collected included patient demographics, units of blood transfused, intensive care unit (ICU) and hospital days, ventilator days, injury severity score (ISS), mortality, presence of acute respiratory distress syndrome (ARDS), and infectious complications. A multiple organ dysfunction syndrome (MODS) score was calculated.

Results

The distribution of patients was as follows: 284 patients received only NLR blood, 153 received only LR blood, and 58 received at least one unit of each. The mean ISS was similar (NLR: 26, LR: 24; P > 0.1). No differences were seen between groups in units transfused (6.2 vs. 5.5), number of ICU days (8.2 vs. 9.0), number of hospital days (16.9 vs. 18.6), number of ventilator days (6.1 vs. 5.7), incidence of ARDS (8.3% vs. 8.5%), MODS score (5.5 vs. 5.9), mortality rate (15.1% vs. 15.7%), or infection rate (36% vs. 30%) (P > 0.1).

Conclusions

This study represents the largest series comparing trauma patients who received either LR or standard blood transfusions. The use of LR blood does not improve outcome in trauma patients.

Estimating the cost of blood: past, present, and future directions

Understanding the costs associated with blood products requires sophisticated knowledge about transfusion medicine and is attracting the attention of clinical and administrative healthcare sectors worldwide. To improve outcomes, blood usage must be optimized and expenditures controlled so that resources may be channeled toward other diagnostic, therapeutic, and technological initiatives. Estimating blood costs, however, is a complex undertaking, surpassing simple supply versus demand economics. Shrinking donor availability and application of a precautionary principle to minimize transfusion risks are factors that continue to drive the cost of blood products upward. Recognizing that historical accounting attempts to determine blood costs have varied in scope, perspective, and methodology, new approaches have been initiated to identify all potential cost elements related to blood and blood product administration. Activities are also under way to tie these elements together in a comprehensive and practical model that will be applicable to all single-donor blood products without regard to practice type (e.g., academic, private, multi- or single-center clinic). These initiatives, their rationale, importance, and future directions are described.

Managing the risk of transmission of variant Creutzfeldt Jakob disease by blood products

Whereas plasma-derived clotting factor concentrates now have a very good safety record for not being infectious for lipid enveloped viruses, concern has arisen about the possibility that prion diseases might be transmitted by blood products. There is epidemiological evidence that classical sporadic Creutzfeld Jakob disease (CJD) is not transmitted by blood transfusion. There is now good evidence that the abnormal prion associated with variant CJD can be transmitted by transfusion of fresh blood components and infect recipients. To reduce the risk of the pathological prion in the UK infecting recipients of clotting factor concentrates, these are now only manufactured from imported plasma collected from countries where there has not been bovine spongiform encephalopathy (BSE) in cattle and the risk of variant CJD in the population is, therefore, considered negligible. The safety of these concentrates is also enhanced because prion protein is, to an appreciable extent, excluded by the manufacturing process from the final product. To help reduce the chance of prion transmission by fresh blood products, donations are leucodepleted, there is increasing use of imported fresh frozen plasma (especially for treating children) and potential donors, who have been recipients of blood since 1980 (the beginning of the BSE epidemic in cattle) are deferred.

Pre-storage leucocyte depletion and transfusion reaction rates in cancer patients

Passenger leucocytes transfused with allogenic blood are responsible for potential adverse effects. The impact of pre-storage leucodepletion (in-line filtration) of all whole blood units on transfusion reaction rate among patients suffering from cancer was retrospectively studied, comparing all reactions following red blood cell (RBC) transfusions during 2 years of pre-storage vs. 2 years of selective (bedside) leucodepletion. During selective leucodepletion, 5165 RBC units - of which 2745 were bedside filtered units- were transfused to 866 patients. Twenty-eight reactions were recorded: 22 (15 in the bedside group) febrile non-haemolytic transfusion reactions (FNHTR) and six allergic reactions (five in the bedside group). The overall percentage of reactions was 0.54 (0.76 for bedside) and 0.42 for FNHTR (0.54 for bedside). During pre-storage leucodepletion, 4116 RBC units were transfused to 841 patients. Eleven reactions were recorded: four FNHTR and seven allergic reactions (urticaria). The percentage of reactions for transfused RBC units was 0.26 (0.09 for FNHTR). Comparison between pre-storage filtration and bedside filtration with regard to FNHTR showed an odds ratio of 2.80 (95% confidence interval = 0.83-14.87) for bedside filtration. The study suggests that, for transfused patients affected by cancer, pre-storage leucodepletion is more effective than selective (bedside) filtration in reducing the incidence of transfusion reactions (FNHTR).

Positively charged porphyrins: a new series of photosensitizers for sterilization of RBCs

BACKGROUND

Photodynamic treatment could be a way to inactivate pathogens in RBCs. The objective of this study was to characterize the virucidal activity and RBC-damaging activity of a series of cationic porphyrins. Using the most efficacious photosensitizer, various in-vitro human RBC quality variables and in-vivo RBC survival in Rhesus monkeys were evaluated.

STUDY DESIGN AND METHODS

RBCs, spiked with 5 log of extracellular VSV, were treated with porphyrins (25 micro mol/L) and red light (100 W/m2) and essayed for virucidal activity. In-vitro RBC quality variables were assessed during 5 weeks of storage in various ASs. In-vivo survival was investigated with autologous RBCs in Rhesus monkeys.

RESULTS

Tri-P(4) was by far the best sensitizer of a series tested, giving the least hemolysis under conditions that resulted in 5 log-kill of extracellular VSV. Under our experimental conditions, the percentage hemolysis in treated cells was 5.1 +/- 1.1 percent after 5 weeks of storage in SAG-M compared to 1.9 +/- 1.1 percent in the untreated control. Storage in AS-3 resulted hemolysis of 2.3 +/- 1.9 percent. With the exception of IgG binding and potassium leakage, RBC quality variables remained unchanged after photodynamic treatment. Addition of reduced glutathione (GSH) during treatment reduced IgG binding. The 24-hour recovery and T50 of treated RBCs in Rhesus monkeys were satisfactory.

CONCLUSION

Porphyrin Tri-P(4) may be a suitable photosensitizer for sterilization of RBCs. However, further exploration to optimize the method is necessary to reach clinically acceptable goals.

A lack of serologic evidence of transmission of Chlamydia pneumoniae by transfusion of buffy coat-depleted RBCs

BACKGROUND

Recent studies have shown that a high percentage of blood donors harbor Chlamydia pneumoniae DNA and antigens within their PBMNCs. The aim of the present study was to investigate whether recipients of RBC transfusions who were seronegative for C. pneumoniae before transfusion showed any evidence of seroconversion after transfusion.

STUDY DESIGN AND METHODS

Patients who were possible recipients of RBC transfusion and negative in a screen test for IgG antibodies against C. pneumoniae at the time of blood group determination were candidates to be included in the study. The patients were contacted 3.0 to 3.5 months after the blood group determination, and those who accepted to participate agreed that another venous blood sample could be taken.

RESULTS

Among the patients who participated, 53 had become recipients of RBC transfusion (transfused group), and 51 later did not receive any RBC transfusion (control group). No significant change was found in IgG titer against C. pneumoniae between the first and the second sample from the same patient, in either the transfused group or the control group.

CONCLUSION

In our study, which was limited to 53 seronegative recipients of RBC units from seropositive donors, we found no serologic evidence that C. pneumoniae could be transmitted by RBC transfusion.

Lymphocyte T subsets and natural killer cells in Italian and Philippino blood donors

BACKGROUND AND OBJECTIVES

The characterization of lymphocyte subsets in blood donors has been utilized to determine the normal ranges that can be related to race. A study was performed in blood donors from two racial groups - Caucasian (Italians) and Asian (Philippinos) - to define respective T-lymphocyte subsets and levels of cytokines.

MATERIALS AND METHODS

Ninety-two blood donors (46 Italians and 46 Philippinos) were enrolled. Blood count and immunophenotyping of lymphocytes by flow cytometry were carried out, and cytokine production was tested in six blood donors of each group.

RESULTS

Philippino blood donors showed a significantly higher mean value of leucocytes (P = 0.01) and lymphocytes (P < 0.001) than Italians. The mean absolute count of lymphocyte subsets CD3- CD16+ CD56+ and CD3+ CD8+ were both significantly higher in Philippino than in Italian subjects, respectively, P < 0.01 and P < 0.0001. Philippinos showed a statistically significant higher frequency of lymphocytes producing interferon-gamma (IFN-gamma) compared to Italians (P = 0.02).

CONCLUSIONS

T-lymphocyte subsets in Italian and Philippino blood donors seem to be correlated to ethnic background. The higher levels of CD3+ CD8+ T cells, natural killer (NK) cells and IFN-gamma-producing cells found in Philippinos suggest leucoreduction in Asian blood donors.

Variant Creutzfeldt-Jakob disease and blood transfusion

Variant Creutzfeldt-Jakob disease (vCJD) was first described in the United Kingdom in 1996 and is thought to have been transmitted from cattle infected with bovine spongiform encephalopathy probably via the food chain. Thus far just over 100 definite or probable clinical cases have been described, though the number of people currently infected and the eventual size and geographic distribution of any future clinical epidemic remain uncertain. There is little evidence that sporadic CJD is transmitted by blood transfusion. However, the same cannot necessarily be assumed to apply to the new variant strain of disease in which involvement of peripheral lymphoid tissues has been demonstrated. In the face of uncertainty surrounding the risk of transmission of vCJD by blood products, blood transfusion services in a number of countries have implemented precautionary policies, though whether in the long term these will prove to have been necessary or sufficient remains to be seen.