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PubMed2007

Blood cell separation using amphiphilic copolymers containing N,N-dimethylacrylamide.

To develop leukocyte removal filters effective for whole blood, amphiphilic copolymers based on N,N-dimethylacrylamide were synthesized and evaluated as coating materials for poly(ethylene terephthalate) filters. The copolymers with methyl methacrylate or 2-hydroxypropyl methacrylate as a comonomer showed higher platelet permeation ratios (more than 90%) than that of the copolymer with n-butyl methacrylate, though the logarithmic reductions of leukocytes by these copolymers were less than four. An increase in the platelet permeation for whole blood tended to increase the leukocyte permeation. The permeation of both platelets and leukocytes increased with the amount of copolymer coated on the filters because of the change in the physical properties such as the average pore size, total surface area, and total pore volume of coated filters. These results confirm that both the chemical and physical properties of the filters play important roles to control the permeation behavior.

Acrylamides↗
PubMed2006

Blood bank issues associated with red cell exchanges in sickle cell disease.

Sickle cell disease (SCD) patients are prone to develop complications that include stroke, acute chest syndrome, and other crises. Some of these complications require chronic transfusion therapy or red cell exchange (RCE), either for therapeutic or prophylactic reasons. Due to a discrepancy of red cell antigens between African Americans and Caucasians (majority blood donors), the incidence of alloantibody formation is very high, which makes it difficult to find compatible red cell units, especially for urgent RCE. Some of the above conditions require immediate oxygen delivery to the tissues. Thus, SCD patients undergoing RCE should receive red blood cells with special attributes that include matching for Rh and Kell blood group antigens; RBCs should be fresh in order to provide (1) immediate oxygen delivery and (2) longer surviving cells to reduce the interval between RCE. Also, these units should be pre-storage leukoreduced to prevent febrile non-hemolytic reactions and screened for sickle cell traits to avoid transfusing red cells containing HbS. This requires a concerted effort between the apheresis unit, the local blood bank, and the central blood supplier.

2,3-Diphosphoglycerate↗
PubMed2005

Can a leukocyte depletion filter (LDF) reduce the risk of reintroduction of hepatocellular carcinoma cells?

During liver transplantation for hepatocellular carcinoma (HCC) patients, HCC could theoretically be introduced into the systemic circulation when salvaged blood is used with an autotransfusion device. Several reports have shown that some types of leukocyte depletion filters (LDFs) could completely reduce the risk for reintroducing some types of tumor cells. In this study, we tested the ability of the LDF (RCEZ1T, Pall Biomedical Co, NY, USA) to reduce the risk for reintroducing HCC cells in vitro by using a very sensitive detection method. We divided the test group into 6 groups: group I was 10 cells, group II was 20 cells, group III was 2 x 10(3) cells, group IV was 2 x 10(5) cells, group V was 2 x 10(6) cells, and group VI was 2 x 10(7) cells. The counted cells in 200 mL saline were passed through the RCEZ1T using the force of gravity. To identify the presence of cells, the pellet was resuspended, and polymerase chain reaction (PCR) was performed. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH), a housekeeping gene, was used as a primer. In groups I and II, the HCC cells were completely filtered in all experiments. However, in groups III, IV, and V, the HCC cells were not completely filtered in a few of the repeated experiments, with the unfiltered rate of tumor cells being between 8% and 20%. In group VI, the HCC cells were not completely filtered in all the repeated experiments. In conclusion, the RCEZ1T filter markedly reduced the risk for reintroduction of HCC cells. However, at high HCC cell load the filter cannot completely remove all the tumor cells. Further studies are required to assess the impact in clinical settings.

Carcinoma, Hepatocellular↗
PubMed2006

Leukocyte removal therapy for ulcerative colitis does not affect postoperative complications.

BACKGROUND: We investigated the incidence of postoperative complications in patients treated with or without preoperative leukocyte removal therapy (LRT). METHODS: The case notes of 387 patients with ulcerative colitis (UC) who underwent surgical intervention were retrospectively reviewed. One hundred nine patients were treated with LRT within 8 weeks before surgery (LRT group), and 278 had not received LRT since at least 8 weeks before surgery (without LRT group). We reviewed the postoperative complications according to type of initial operation. RESULTS: Of the patients who underwent an ileal J-pouch anal anastomosis (IPAA) without an ileostomy, 3 (6.5%) in the LRT group developed pouch-related complications (PRC), while 11 (7.5%) in the without LRT group developed PRC. The overall postoperative complication rates were 28.3% in the LRT group and 21.8% in the without LRT group. For patients who underwent an IPAA with an ileostomy, the overall rates of postoperative complications were 39.1% in the LRT group and 31.8% in the without LRT group. Among those undergoing a total colectomy, 33.3% in the LRT group and 18.2% in the without LRT group had postoperative complications. No statistically significant differences were demonstrated between the two groups with respect to postoperative complications. CONCLUSIONS: Our results suggest that preoperative LRT does not influence the rate of postoperative complications in UC patients.

Adolescent↗
PubMed2004

Effect of leukocyte depletion on endothelial cell activation and transendothelial migration of leukocytes during cardiopulmonary bypass.

BACKGROUND: Although leukocyte depletion from systemic circulation during cardiopulmonary bypass (CPB) has been studied, the effect of leukocyte depletion on the leukocyte-endothelial cascade remains poorly understood. So far, there has been no published work on the effects of leukocyte filters during cardiac operations from the viewpoint of endothelial activation and transendothelial neutrophil migration. METHODS: Thirty-two patients undergoing elective heart operations were randomly allocated to a leukocyte-depletion (LD) group or a control group. Blood samples were collected at seven time points: before sternotomy, at 30 minutes and at 60 minutes of CPB, at 5 minutes after coronary reperfusion, at the end of CPB, and at 2 hours and 24 hours after the cessation of CPB. The plasma concentrations of P-selectin, intercellular adhesion molecule-1 (ICAM-1), interleukin-8, and platelet-endothelial cell adhesion molecule-1 (PECAM-1) were measured using enzyme-linked immunosorbent assays. Plasma malondialdehyde (MDA) concentration was determined by measurement of thiobarbituric acid-reactive substances in plasma. In addition, blood samples collected at intervals before and after operation were used for arterial blood gases. RESULTS: Our studies show significant increases of plasma levels of P-selectin, ICAM-1, interleukin-8, PECAM-1, and MDA during and after CPB in the control group. Interestingly, a significant decrease of plasma levels of P-selectin, ICAM-1, interleukin-8, PECAM-1, and MDA, and better preservation of lung function could be found in the LD group compared with the control group. CONCLUSIONS: Our results demonstrate a rationale for using a leukocyte filter in patients undergoing cardiac surgery to attenuate the endothelial-mediated component of the CPB-induced inflammatory response by reducing endothelial activation and neutrophil transmigration.

Adult↗
PubMed2005

Changes in P-selectin expression on cardiac microvessels in blood-perfused rat hearts subjected to ischemia-reperfusion.

BACKGROUND: During cardiac surgery involving cardiopulmonary bypass, activation of polymorphonuclear cells is believed to contribute to ischemia-reperfusion injury and subsequent myocardial impairment of function. The early tethering of polymorphonuclear cells to blood vessel walls depends upon recognition of the adhesion molecule P-selectin on endothelium. The purpose of this study was to define the kinetic changes in expression of P-selectin on myocardial vessels in a model of global ischemia-reperfusion injury. METHODS: In a novel recirculating blood-based perfusion system, rat hearts were subjected to 30 minutes of aerobic perfusion, 60 minutes of global ischemia, and 60 minutes of reperfusion, or to 120 minutes of continuous aerobic blood perfusion (with or without leukocyte/platelet depletion). Heart function (left ventricular developed pressure), heart rate, and perfusion pressure were monitored throughout. Hearts were sampled at defined periods for microvascular expression of P-selectin, identified by immunohistochemistry. RESULTS: In control (nonperfused) hearts and in hearts subjected to perfusion and ischemia, few cardiac vessels (8% to 16%) expressed P-selectin. After 15 minutes of reperfusion, P-selectin was present on the majority of vessels (77%; p < 0.05) but expression decreased subsequently throughout the remaining duration of reperfusion. Interestingly, upregulation of P-selectin also occurred when hearts were subjected to continuous perfusion alone (no ischemia), but this upregulation was less rapid. Depletion of leukocytes/platelets from the blood perfusate did not modify P-selectin expression. CONCLUSIONS: The augmented expression of P-selectin on myocardial vessels during reperfusion of ischemic hearts probably reflects changes induced during global ischemia and by the duration of perfusion through the nonbiological tubing of the circuit. That is likely to mimic the effects initiated during cardiopulmonary bypass.

Aerobiosis↗
PubMed2005

Invited commentary.

Explore the source record for details and available documents.

Coronary Artery Bypass↗
PubMed2005

Effects of a leukocyte depleting arterial line filter on perioperative morbidity in patients undergoing cardiac surgery: a controlled randomized trial.

BACKGROUND: Activated leukocytes may increase morbidity in cardiac surgery. The objective of this study is to investigate the influence on morbidity of leukocyte-depleting blood filters placed into the arterial line of cardiopulmonary bypass circuits. METHODS: Simple, blind, prospective, randomized and controlled clinical trial carried out in a cardiac surgery ICU at a university center. We included 159 consecutive low-risk patients (ie, Parsonnet score < 10) undergoing cardiac surgery who were initially stratified in three risk levels according to the Parsonnet score at admission into the hospital (ie, low, < 4; middle, 4 to 7; and high, 8 to 10). Once stratified, all patients were randomized to undergo cardiopulmonary bypass either with a conventional blood filter or with a leukocyte filter (randomization ratio, 2:1). The outcome variable was morbidity. Patients were considered to have a high morbidity if any of the following clinical situations were present (ie, pulmonary dysfunction, cardiac dysfunction, perioperative infections, postoperative hyperthermia, and hyperdynamic states). RESULTS: The leukocyte filter was used in 52 patients and the conventional filter in 107 patients. The morbidity rate was similar in both groups, but patients with leukocyte filter had a lower incidence of perioperative infections, fever, and hyperdynamic states as compared with patients with the conventional filter. CONCLUSIONS: Leukocyte filtration in patients undergoing cardiac surgery with extracorporeal perfusion showed no measurable effects on postoperative morbidity. However, although not statistically significant, a decrease was observed in the rates of perioperative infection, fever, and hyperdynamic states.

Blood Transfusion↗
PubMed2006

Can only partial T-cell depletion of the graft before hematopoietic stem cell transplantation mitigate graft-versus-host disease while preserving a graft-versus-leukemia reaction? A prospective phase II study.

The study comprised 37 consecutive patients who underwent transplantation with a Campath-1H in vitro T cell-depleted granulocyte colony-stimulating factor-mobilized peripheral blood stem cell graft from an HLA-identical sibling, followed 24 hours later by an unmanipulated graft. Acute graft-versus-host disease (GVHD) was limited to grade I to II, whereas chronic graft-versus-host disease occurred in 9 patients, mostly (n = 7) with limited disease. Molecular relapses (8 chronic myeloid leukemia [CML] and 1 non-Hodgkin lymphoma) that occurred not earlier than the sixth month after transplantation were treated with donor lymphocyte infusion (DLI), which induced complete remission in all but 1 CML patient with persistent very low BCR-ABL molecular levels. With a median follow-up of 54 months (range, 29-84 months), the actuarial 5-year overall survival, disease-free survival, and transplant-related mortality are 78% (95% confidence interval [CI], 52%-88%), 78% (95% CI, 52%-86%), and 6% (95% CI, 1.5%-32%), respectively. All CML patients are alive and free of disease. The results of this prospective, nonrandomized study show that incomplete T-cell depletion in vitro with Campath-1H (in combination with DLI for molecular relapses in CML) may decrease the incidence of GVHD and transplant-related mortality with no adverse effect on disease-free survival. The described method decreases the number of T cells to an extent that severe GVHD is prevented while relapse is postponed to a time when the patient can be treated with DLI without severe side effects.

Adolescent↗
PubMed2006

T-cell depleted peripheral blood stem cell allotransplantation with T-cell add-back for patients with hematological malignancies: effect of chronic GVHD on outcome.

One hundred thirty-eight patients with hematologic malignancies received myeloablative T cell-depleted peripheral blood stem cell transplant (PBSCT) from an HLA-identical sibling donor. The T cell dose was adjusted to 0.2-1 x 10(5) CD3(+) cells/kg. The CD34 dose was 2.7-16 x 10(6)/kg. Patients with acute graft-versus-host disease (GVHD) grade <2 received 1 or 2 donor lymphocyte infusions of 10(7) CD3(+) cells/kg between days 45 and 100. Patients were designated according to relapse probability as standard or high relapse risk (77 and 61, respectively). Overall survival (OS), relapse-free survival, relapse, and transplant-related mortality (TRM) were 58%, 46%, 40%, and 20%, respectively, after a median follow-up of 4 years. Fifty-three (39%) and 21 (15%) patients developed grade 2-4 and 3-4 acute GVHD. Forty-two (36%) had limited and 29 (25%) had extensive chronic GVHD. In multivariate analysis, disease risk was an independent factor for OS and relapse, day-30 lymphocyte count for OS and TRM, and chronic GVHD for OS and relapse. PBSCT with early T cell add back leads to comparable rates of chronic GVHD compared with T cell-replete PBSCT. However, this chronic GVHD after T cell add back is associated with less mortality and retains a protective effect in terms of relapse, at least in the standard-risk patients.

Adolescent↗
PubMed2005

New treatments for SLE: cell-depleting and anti-cytokine therapies.

Although systemic lupus erythematosus (SLE) is indeed a complex autoimmune disease, recent advances in our understanding of lupus pathogenesis have suggested new, targeted approaches to therapy. The purpose of this review is to discuss the underlying scientific rationale and results of first clinical studies of new treatment approaches to SLE, with a focus on cell-depleting therapies and cytokine blockade. It has become clear that the B lymphocyte plays a key role in disease pathogenesis by both autoantibody-dependent and autoantibody-independent mechanisms. Additionally, aberrant interactions between B and T cells are critical to disease emergence and progression. New agents that directly target immune cells abnormal in SLE include the B-cell depleting or modulating antibodies, rituximab (anti-CD20) and epratuzumab (anti-CD22) and the anti-dsDNA tolerogen LJP394. Another promising approach has been to block co-stimulatory interactions between T and B cells, for example by inhibiting the CD40-CD40 ligand pathway with anti-CD40 ligand monoclonal antibody or the B7 pathway with CTLA-4Ig. Immune cells can also be manipulated indirectly through cytokine effects. For B cells, anti-BAFF (B-cell activation factor of the tumor necrosis family) provides an example of this approach. Other, more pleiotropic cytokines can likewise be blocked in SLE. In addition to the blockade of interleukin-10 (IL-10), the first anti-cytokine approach examined, it is mainly anti-tumor necrosis factor therapy that has come into focus, holding promise for some patients with lupus nephritis. The majority of the available data on these new treatment approaches stems from open-label trials, but controlled trials are under way. Moreover, many additional cytokines, such as interleukin (IL)-6, IL-18, and the type I interferons, represent interesting future targets.

Animals↗
PubMed2005

Non-pharmacologic approaches to graft-versus-host prevention.

Allogeneic transplant offers a curative option for selected hematological malignancies and improved disease free survival in those where cure is not possible. For patients in these categories, Graft-versus-host disease (GVHD) occurs often and is a significant cause of morbidity and mortality following transplantation. Pharmacological immunosuppression has considerable toxicity and controls GVHD in about 75% of transplant recipients when used in combination and continually. Thus, there is the need for viable and non-toxic alternatives for GVHD prevention and this is the impetus for seeking novel non-pharmacological strategies. Most techniques directed to this end are based on various permutations of T-cell depletion. Total T-cell depletion was the first graft engineering strategy employed but while beneficial, it was associated with delay in engraftment and early relapses. Modern depletion and adoptive immunotherapy techniques are directed toward specific subsets of T-cells which include alloreactive, naive, NK cells, T-helper and cytotoxic T-cells. While large bodies of preclinical evidence attest to the efficacy of currently available non-pharmacological prevention techniques, such is not the case with vigorous clinical trials. Where available, the proven non-pharmacological prevention techniques are yet to be fully interwoven into the patient care arena. Integration of available strategies and continuing research are therefore acutely needed to improve the chronic morbidity and mortality seen with both allogeneic transplant-associated GVHD and the use of pharmaceutical immunosuppressants.

Graft vs Host Disease↗
PubMed2006

Chemokine production and pattern recognition receptor (PRR) expression in whole blood stimulated with pathogen-associated molecular patterns (PAMPs).

Recognition of conserved bacterial structures called pathogen-associated molecular patterns (PAMPs) by pattern recognition receptors (PRRs), may lead to induction of a variety of "early immediate genes" such as chemokines. In the current study, we have in an ex vivo whole blood model studied the induction of the chemokines MIP-1alpha, MCP-1 and IL-8 by various PAMPs. The rate of appearance of Escherichia coli-Lipopolysaccharide (LPS) induced chemokines differed. The production of MIP-1alpha and IL-8 was after 1 h of stimulation significantly higher when compared to unstimulated whole blood, whereas MCP-1 was not significantly elevated until after 3 h. At peak levels the MIP-1alpha concentration induced by E. coli-LPS was 3-5-fold higher than MCP-1 and IL-8. By specific cell depletion, we demonstrated that all three chemokines were mainly produced by monocytes. However, the mRNA results showed that IL-8 was induced in both monocytes and granulocytes. The production of all three chemokines, induced by the E. coli-LPS and Neisseria meningitidis-LPS, was significantly inhibited by antibodies against CD14 and TLR4, implying these receptors to be of importance for the effects of LPS in whole blood. The chemokine production induced by lipoteichoic acid (LTA) and non-mannose-capped lipoarabinomannan (AraLAM) was, however, less efficiently blocked by antibodies against CD14 and TLR2. E. coli-LPS and LTA induced a dose-dependent increase of CD14, TLR2 and TLR4 expression on monocytes in whole blood. These data show that PAMPs may induce chemokine production in whole blood and that antibodies against PRRs inhibit the production to different extent.

Antibodies, Monoclonal↗
PubMed2006

The role of leukocyte depleting filters in heart transplantation: early outcomes in prospective, randomized clinical trial.

OBJECTIVE: Leukocyte-mediated reperfusion injury to cardiac allograft in the perioperative period is most likely associated with the early and late mortality after heart transplantation (Htx). Our aim is to determine the efficacy and safety of using leukocyte-depleting filters in a cardiopulmonary bypass (CPB) and secondary blood cardioplegia (SBC) circuit in Htx. METHODS: A prospective, randomized trial was performed in 40 patients undergoing orthotopic Htx. These patients were divided into two groups, to be treated with either leukocyte-depleted (LD) reperfusion (n=20) in the LD group, or whole blood reperfusion (n=20) in the Control group. The SBC was used in both groups. RESULTS: Intraoperatively, the LD group presented the reduced markers of reperfusion injury. The course of the creatine kinase MB (CK-MB) releases was significantly lower in the LD group (p<0.05). The LD hearts showed better spontaneous rhythm resumption (60% vs 10%; p<0.001), and lower need for isoprenaline (0.02+/-0.01 microg/(kg min) vs 0.03+/-0.02 microg/(kg min); p<0.05) and epicardial pacing (25% vs 60%; p<0.05) for weaning off CPB. Postoperatively, lower and shorter need for inotropic support (48+/-46, median=35 h vs 131+/-68, median=109 h; p<0.001), shorter temporary epicardial pacing (6+/-14, median=0 h vs 25+/-52, median=1 h; p<0.01), and lower 24-h chest drainage (551+/-274, median=500 ml vs 973+/-836, median=665 ml; p<0.05) in the LD group contributed to the shorter mechanical ventilation time (8+/-3, median=7.5 h vs 14+/-12, median=8.5 h; p<0.05) and the shorter stay at an intensive care unit (ICU) (70+/-24 h vs 116+/-73 h; p<0.05). The 30-day mortality was zero in both groups. CONCLUSIONS: The use of leukocyte depleting filters in heart transplantation is an effective, easy and safe method of myocardial protection, reducing significant myocardial reperfusion injury and improving posttransplant graft functional recovery.

Adult↗
PubMed2006

Alloreactive T cell clonotype recruitment in a mixed lymphocyte reaction: implications for graft engineering.

OBJECTIVE: The selective elimination of alloreactive T cells from donor stem cell grafts prior to hematopoietic stem cell transplantation (HSCT) is an important goal in the prevention of graft-vs-host disease (GVHD). However, in HLA-identical donor-recipient pairs, it has proven difficult to identify alloreactive T cells using in vitro systems pretransplant due, in part, to their low frequency and a lack of methodological standardization. To better understand the alloresponse between HLA-identical related pairs, we characterized the alloreactive T cells generated in a mixed lymphocyte reaction (MLR) assay system. METHODS: HSCT donor peripheral blood mononuclear cells (responder) were labeled with carboxyfluorescein diacetate, succinimidyl ester (CFSE) dye and cocultured with irradiated HSCT recipient cells (stimulator) in a one-way MLR. Alloreactive T cells were sorted by upregulation of activation markers (CD25 in most cases) and the responding clonotypes were defined by sequencing the complementarity region 3 (CDR3) of the T cell receptor beta-chain. RESULTS: We show that the recruitment of alloreactive CD4(+) T cells is highly variable. Oligoclonal CD4(+) T-cell expansions in repeated MLRs performed in the same donor-recipient pair showed inconsistent recruitment of clonotypes. The recruitment of alloreactive CD8(+) T cells was more consistent in repeated assays, with the same clonotypes identified in the same donor-recipient pair performed under different conditions. CONCLUSION: Taken together, our data show that even in culture conditions constrained to eliminate background proliferation, stochastic events and low precursor frequencies preclude reproducible elicitation of immunodominant T cell clonotypes with the potential to cause GVHD.

Antigens, Surface↗
PubMed2006

Leukoreduction before red blood cell transfusion has no impact on mortality in trauma patients.

BACKGROUND: Studies suggest that leukocytes in donated blood increase mortality and length of hospital stay (LOS) after transfusion. These studies included few trauma patients, however. Many institutions now mandate leukoreduction (LR) of transfusion products, which increases costs by approximately $30/unit. The purpose of this study was to examine the effect of LR on mortality and LOS in trauma patients. METHODS: A retrospective before-and-after cohort study was conducted at a level one urban trauma center. LR of all transfusion products commenced in January 2002. All patients treated within the intervention period (March 2002 through January 2004) received LR products. Those transfused during March 2000 through January 2002 served as controls. The trauma registry was queried for patients >or=18 years who survived >or=2 days and received >or=2 units of blood. Mortality and LOS were determined for each group. Subset analysis was performed on patients receiving 2-6 transfusions and those receiving massive transfusion (>or=6 units). Mortality and LOS for control and intervention subsets were compared. Means were compared using Student's t-test, proportions using chi(2) (significance P <or= 0.05). RESULTS: There were 439 patients in the control group and 240 patients in the intervention group. Groups were similar in age and mechanism of injury. There was no difference in mortality overall (P = 0.68) or after massive transfusion (P = 0.14). There was no difference in LOS overall (control, 12 +/- 17 days; intervention, 12 +/- 13.8 days, P = 0.46) or after subset analysis. CONCLUSIONS: In those transfused patients who survive 48 h post-injury, LR of blood transfusion products has no beneficial impact on patient survival or hospital LOS. The associated costs of universal LR are not justified.

Adult↗