Leukocyte-depleted Group Research Articles

Leukocyte-depleted erythrocyte transfusion associated with less ICU stay among pediatrics with cardiac surgery

Perioperative transfusion has adverse effects in patients undergoing cardiac surgery. The effect of leukocyte-depleted (LD) erythrocyte transfusion in pediatrics’ cardiac surgery was until now unknown. A retrospective cohort study was conducted among pediatric patients who were no more than 3 years old and transfused with red blood cells during an open-heart surgery. Investigations were made into mechanical ventilator treatment duration, length of stay in the intensive care unit (ICU) and 90-day survival. A total of 174 pediatric patients were included in our study. The average age was 21.90 months old and the average weight was 9.18 kg. There were 107 patients received non-leukocyte-depleted (NLD) red blood cell (RBC) transfusion and 67 patients received LD erythrocyte transfusion. No statistically significant differences were detected in the 90-day survival rates between the NLD group and the LD group. Statistically significant differences were detected in the time spent on the mechanical ventilator[(5.3 ± 2.0) d vs. (2.6 ± 1.0) d; P= 0.01] and the lengths of ICU stay [(9.4 ± 6.0) d vs. (5.6 ± 4.0) d; P=0.02] between the NLD group and the LD group. LD blood transfusion was associated with decreased length of stay in ICU and the decreased time on the mechanical ventilator in pediatric cardiac surgery.

Effects of leukocyte-depleted allogeneic blood transfusion on perioperative cellular immunity in children

Objective To investigate the effects of leukocyte-depleted allogeneic blood transfusion on perioperafive cellular immunity in children.Methods Three hundred and fifty-nine ASA Ⅰ or Ⅱ children aged 3 month-14 yr,weighing 5-74 kg requiring allogeneic blood transfusion during operation were randomly divided into 2 groups:control group (group C,n =163) and leukocyte depletion group (group D,n =196).In group D allogeneic blood was filtered with a leukocyte filter before being transfused during operation.Blood samples were collected from peripheral vein before blood transfusion,and at 2 and 6 d after blood transfusion for determination of levels of CD3+,CD4+,CD8+,and CD56+ by flow cytometry.CD4+/CD8+ ratio was calculated.The volume of allogeneic blood transfused during operation,the duration of operation,postoperative drainage,antibiotics administration and hospital stay and incidence of postoperative infection were recorded.Results The levels of CD3+,CD4+,CD56+ and CD4+/CD8+ ratio were significantly increased at 6 d after blood transfusion while the duration of postoperative drainage,postoperative antibiotics administration and hospital stay and incidence of postoperative infection were significantly decreased in group D compared with group C.Conclusion Leukocyte-depleted allogeneic blood transfusion is helpful in improving the postoperative cellular immunity in children. Key words: Leukspheresis; Blood transfusion; Immunity, cellular; Child

Effect of leukocyte-depleted intraoperative salvaged Mood on erythrocyte immunity and systemic inflammatory response during perioperative period

Objective To investigate the effect of leukocyte-depleted intraoperative salvaged blood on the erythrocyte immunity and systemic inflammatory response during the perioperative period in patients. Methods Twenty ASA Ⅰ or Ⅱ patients, aged 20-44 yr, weighing 40-75 kg, required blood salvage during operations (intraoperative blood loss expected 15-20 ml/kg), were randomly divided into 2 groups ( n = 10 each): control group (group C) and leukocyte depletion group (group D) . Anesthesia was induced with midazolam, fentanyl, propofol and vecuronium and maintained with isoflurane inhalation and iv infusion of propofol and remifentanil. The patients were mechanically ventilated after tracheal intubation. Intraoperative blood salvage and reinfusion were performed in all patients using cell saver system. In group D, the salvaged blood was filtered with a leukocyte depleting filter placed in the line of the reinfusion circuit. Blood samples were collected from the central vein before anesthesia (T1 ) , at the end of surgery (T2 ) , and at 12 h (T3 ) and 36 h (T4 ) after operation in the two groups. The rosette rates of RBC-C3b receptors and RBC-immune complex were determined. The leukocyte and neutrophil were counted. The plasma levels of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α) and malondialdehyde (MDA) were measured. Results The plasma levels of IL-6, TNF-a and MDA were significantly lower at T2-4 , the rosette rate of RBC-C3b receptors was significantly higher at T3-4 ( P ＜ 0.01) , and the neutrophil count was significantly lower at T4 in group D than in group C ( P ＜ 0.05) . Conclusion Leukocyte-depleted intraoperative salvaged blood is helpful to improve the erythrocyte immunity during the perioperative period in patients, and the decrease in the systemic inflammatory response may be involved in the mechanism. Key words: Leukapheresis; Blood transfusion,autologous; Immunity, cellular; Erythrocytes; Inflammation

Establishment of a off-pump leukocyte depletion method in canines

Objective To establish a off-pump leukocyte depletion method in canines.Methods Twenty-one healthy adult mongrel dogs of both sexes, weighing 10-12 kg, were randomized into 2 groups: control group (group C, n = 9) and leukocyte depletion group (group LD, n = 12) . An extracorporeal leukocyte filtration end was constructed by aseptic puncture of the bilateral external jugular veins via a blood transfusion line and the leukocyte filter for extracorporeal leukocyte depletion. In group LD, blood was filtered with a MP-300 blood line and a SQ40S leucocyte depletion filter one end placed in the right external jugular vein (artery end) and the other end placed in the left external jugular vein (venous end). After heparin anticoagulation, a MP-300 blood line pump was used as the power. Blood was filtered at a rate of 75 ml/min and it was maintained for 60 min. The artery end was then closed, normal saline injected into the closed circuit, the remaining blood pumped into the body, and then the venous end closed. In group C, aseptic puncture of the bilateral external jugular veins was performed. Arterial blood samples were taken immediately before leukodepletion (baseline, T_0 ) , at 10, 20, 30, 40, 50 and 60 min of leukodepletion (T_(1-6) , depletion period), and at 10, 20, 30, 40, 50, 60, 120, 180 and 270 min after leukodepletion (T_(7-15) , recovery period) for determination of blood routine. MAP, HR, RBC.Plt and body temperature were recorded at T_0 , T_6 , T_(12) and T_(15) . Results There were no significant difference in MAP and RBC between the two groups ( P > 0.05 ) . HR, body temperature, and Plt were significantly lower in group LD than in group C (P 0.05 ). Conclusion The off-pump leukocyte depletion method is successfully established and has exact efficacy with less adverse effects in this study. Key words: Leukapheresis; Methods

Leucocyte depletion of perioperative blood transfusion does not affect long-term survival and recurrence in patients with gastrointestinal cancer

Perioperative red blood cell (RBC) transfusion may be associated with a poor prognosis in cancer surgery. Allogeneic leucocytes are assumed to play a causal role. This study evaluated the long-term effect of transfusion with leucocyte-depleted (LD) blood in patients with gastrointestinal cancer. The Transfusion Associated Complications = Transfusion Induced Complications? (TACTIC) study is a multicentre randomized controlled trial evaluating the short-term benefits of LD versus non-LD RBC transfusions. The present study evaluated 5-year survival and cancer recurrence among 512 patients with gastrointestinal cancer included in the TACTIC study. Some 89.2 per cent of patients had a primary tumour and 79.7 per cent underwent surgery with curative intent; 243 patients received perioperative RBC transfusion (median 3 units). The 5-year overall survival rate of patients with any type of gastrointestinal cancer was 50.8 per cent in the LD group and 45.8 per cent in the non-LD group (P = 0.191). Corresponding 5-year disease-free survival rates were 60.0 and 56.6 per cent (P = 0.482), and recurrence rates 32.9 and 34.3 per cent (P = 0.864). Leucocyte depletion is not associated with better long-term survival and lower recurrence rates in patients with gastrointestinal cancer.

Leucocyte-depleted Blood Cardioplegia

The effect of the depletion of leucocytes from cardioplegic and initial myocardial reperfusion blood on the inflammatory response and myocardial protection in patients with unstable angina undergoing cardiopulmonary bypass (CPB) was studied. Patients were allocated randomly to a leucocyte-depleted (LD) group or a control group. The LD group received continuous retrograde LD isothermic blood cardioplegia and the control group received isothermic blood cardioplegia. Blood samples were collected at seven time-points before, during and after the procedure. Total leucocyte counts of cardioplegia blood in the LD group were significantly lower than in the control group, but systemic leucocyte and neutrophil counts after CPB did not differ between the groups. The levels of adhesion molecules, cytokines, elastase and malondialdehyde were significantly increased after CPB in both groups and reached peak values 2-6 h after surgery; no other significant differences were found. LD cardioplegia and myocardial reperfusion did not attenuate the endothelial and neutrophil-mediated components of the CPB-induced inflammatory response, which may lead to myocardial reperfusion injury.

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

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. 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. 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. 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.

Does leucocyte depletion during cardiopulmonary bypass improve oxygenation indices in patients with mild lung dysfunction?

Leucocyte-depleting arterial line filters have not dramatically improved lung function after cardiopulmonary bypass (CPB), but patients with pre-existing lung dysfunction may benefit from their use. We randomized 32 patients with mild lung dysfunction having elective first-time coronary revascularization to either a leucocyte depleting or a standard 40-mm arterial line filter during CPB. The alveolar arterial oxygenation index was calculated before and 5 min after CPB, then at 1, 2, 4, 8, and 18 h after surgery. Time to extubation on the ITU was recorded. Preoperative, immediate postoperative, and 24 h postoperative chest x-rays were scored for extravascular lung water. Postoperative alveolar-arterial oxygenation indices were better in the patients who received leucocyte depletion during CPB (1.65+/-0.96 in the study group vs 2.90+/-1.72 in the control group, P<0.05). The duration of postoperative mechanical ventilation was less in the leucocyte-depleted group (4.8+/-2.1 vs 8.3+/-4.7 h in the control group, P<0.05). The extravascular lung water scores immediately postoperatively were 13.0+/-8.6 in the study group vs 19.6+/-10.8 in the control group (P=0.04), and at 24 h postoperatively, 9.7+/-7.7 vs 15.2+/-9.9 for controls. For patients with mild lung dysfunction, a leucocyte-depleting arterial line filter improves postoperative oxygenation, reduces extravascular lung water accumulation, and reduces time on artificial ventilator after CPB. There may be an economic argument for the routine use of leucocyte-depleting filters for every patient during CPB.

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.

Leukocyte depletion attenuates expression of neutrophil adhesion molecules during cardiopulmonary bypass in human beings

Background: On the basis of scanty information, the effects of a leukocyte filter during cardiac operations in human beings have been examined from the viewpoint of the expression of neutrophil adhesion molecules. This study was therefore designed to determine whether leukocyte depletion during cardiopulmonary bypass may interfere with neutrophil adhesion properties. Methods: Twenty-four patients undergoing elective heart operations were randomly allocated to a leukocyte-depletion group or a control group. Blood samples were collected at 7 points: before sternotomy, at 10, 30, and 60 minutes of cardiopulmonary bypass, at termination of cardiopulmonary bypass, 5 minutes after protamine administration, and 2 hours after cardiopulmonary bypass. The expression of the neutrophil surface adhesion molecules L-selectin and β2-integrins was determined by flow cytometric analysis in whole blood. Results: (1) CD11a expression did not change significantly in either group. There were no significant differences between control and leukocyte-depletion groups (P = .63). (2) There was a significantly higher expression of CD11b on the neutrophils during cardiopulmonary bypass in the control group than in the leukocyte-depletion group (P = .01). (3) CD11c expression was initially up-regulated from the onset of cardiopulmonary bypass, reaching a peak at 60 minutes after bypass in the control group (P = .02). The expression of CD11c did not differ significantly between groups (P = .23). (4) L-selectin expression was significantly lower in the leukocyte-depletion group than in the control group (P = .03). Conclusions: The major findings of the present study in human subjects undergoing elective cardiac operations with cardiopulmonary bypass are as follows: (1) bypass was associated with an up-regulation of the adhesion molecules L-selectin, CD11b, and CD11c but with no significant change in CD11a expression, and (2) the clinical use of a leukocyte-depleting filter could down-regulate the expression of CD11b and L-selectin.

A leukocyte depleting filter reduces endothelial cell dysfunction and improves transplanted canine heart function

Background To date leukocytes have been known to play a major role in reperfusion injury and have directed attention to leukocyte-endothelium interaction. This study was designed to investigate how much graft viability and the coronary microcirculatory function could be preserved by leukocyte depletion (LD) in a model of orthotopic cardiac transplantation. Methods The heart in 10 beagle dogs was arrested by introducing a 4°C St. Thomas’ cardioplegic solution. They were harvested, immersed in the cold saline for 3 hours, and then orthotopically transplanted. Five recipients underwent LD (LD group) at reperfusion with the use of a Pall BC1B leukocyte depleting filter inserted into the cardiopulmonary bypass (CPB) circuit. The other 5 dogs without filtration served as a control group. Results Leukocytes were about 80% filtrated and neutrophils were also 85% filtrated during the first 30 minutes of reperfusion in the LD group. A high level of adenosine triphosphate was maintained after transplantation in the LD group. The polymorphonuclear elastase level was significantly lower in the LD group. The cardiac function assessed by the slopes of the end-systolic pressure volume relation after transplantation was significantly higher in the LD group than in the control group ( p < 0.05). The coronary vascular resistance responses to acetylcholine and nitroglycerin after transplantation were preserved significantly better in the LD group than in the control group ( p < 0.05). Conclusions These results suggest that a leukocyte depleting filter placed in the CPB circuit would prevent leukocyte-mediated endothelial cell injury, improve microcirculation of the myocardium, and lead to excellent graft function.

Leukocyte filtration improves brain protection after a prolonged period of hypothermic circulatory arrest: A study in a chronic porcine model

Background: Ischemic cerebral injury follows a well-attested sequence of events, including 3 phases: depolarization, biochemical cascade, and reperfusion injury. Leukocyte infiltration and cytokine-mediated inflammatory reaction are known to play a pivotal role in the reperfusion phase. These events exacerbate the brain injury by impairing the normal microvascular perfusion and through the release of cytotoxic enzymes. The aim of the present study was to determine whether a leukocyte-depleting filter (LeukoGuard LG6, Pall Biomedical, Portsmouth, United Kingdom) could improve the cerebral outcome after hypothermic circulatory arrest. Methods: Twenty pigs (23-30 kg) were randomly assigned to undergo cardiopulmonary bypass with or without a leukocyte-depleting filter before and after a 75-minute period of hypothermic circulatory arrest at 20°C. Electroencephalographic recovery, S-100β protein levels, and cytokine levels (interleukin 1β, interleukin 8, and tumor necrosis factor α) were recorded up to the first postoperative day. Postoperatively, all animals were evaluated daily until death or until electively being put to death on day 7 by using a quantitative behavioral score. A postmortem histologic analysis of the brain was carried out on all animals. Results: The rate of mortality was 2 of 10 in the leukocyte-depletion group and 5 of 10 in control animals. The risk for early death in control animals was 2.5 (95% confidence interval, 0.63-10.0) times higher than that of the leukocyte-depleted animals. The median behavioral score at day 7 was higher in the leukocyte-depletion group (8.5 vs 3.5; P = .04). The median of total histopathologic score was 8.5 in the leukocyte-depletion group and 15.5 in the control group (P = .005). Conclusion: A leukocyte-depleting filter improves brain protection after a prolonged period of hypothermic circulatory arrest. (J Thorac Cardiovasc Surg 2000;120:1131-41)

Leukocyte depletion during cardiac operation: a new approach through the venous bypass circuit

Background. Leukocyte depletion recently has been introduced for cardiac surgical patients to attenuate leukocyte-mediated inflammation and organ reperfusion injury. We evaluated the feasibility of a new leukocyte depletion method in which systemic leukocyte depletion is achieved through the venous side of the cardiopulmonary bypass circuit under low blood flow. Methods. Forty cardiac surgical patients undergoing cardiopulmonary bypass were allocated randomly to a leukocyte depletion group (n = 20) and a control group (n = 20). In the depletion group, leukocyte filtration was achieved with two filter sets located between the venous drainage and the venous reservoir. Leukocyte filtration was commenced after the start of rewarming but before the release of the aortic cross-clamp, and it was driven by a spare roller pump of the heart-lung machine. Results. All the episodes of filtration went smoothly within a period of 10 minutes and with a blood flow rate of 400 mL/min. The mean leukocyte removal rate calculated at the end of filtration was 69%. Circulating leukocytes were reduced by 38% in the depletion group compared with the control group at the moment of cross-clamp release (4.3 × 10 9/L versus 6.8 × 10 9/L, p < 0.05). The postoperative inflammatory response also was reduced as indicated by less production of interleukin-8 ( p < 0.05). Clinically, there was no significant difference between the two groups in postoperative Pa o 2 or pulmonary hemodynamics. Conclusions. It is technically feasible to deplete circulating leukocytes through the venous side of the cardiopulmonary bypass circuit with a low blood flow rate. Future studies should focus on the duration and timing of leukocyte depletion to optimize the methodology of leukocyte depletion for cardiac surgical patients.

Role of platelets in myocardial ischemia-reperfusion injury in dogs.

We investigated the involvement of circulating platelets in myocardial ischemia-reperfusion injury in canine autoperfused heart-lung preparations using filters to deplete platelets and/or leukocytes. The left anterior descending (LAD) coronary artery was occluded for 40 min, followed by 40 min reperfusion, in 3 groups: a leukocyte-platelet-depleted (LPD) group, in which both leukocytes and platelets were depleted; a leukocyte-depleted (LD) group, in which leukocytes alone were depleted; and a control group. There were no differences in hemodynamics or arrhythmias among groups before or during coronary occlusion. After reperfusion, the maximum rate of change in left ventricular pressure during systole and diastole was significantly higher in the LPD group than in the control and LD groups. The LPD group also showed gradual recovery of regional myocardial function and a decrease in the frequency of premature ventricular contractions. The LD group showed a slight improvement in cardiac function and arrhythmias compared with the control group. Although there was no significant difference in the pulmonary arterial plasma level of thromboxane B2 at any stage among groups, the control group showed an increase after reperfusion. These results suggest that platelets are important in reperfusion injury and that the depletion of both leukocytes and platelets effectively protects against reperfusion injury.

Leukocyte depletion results in improved lung function and reduced inflammatory response after cardiac surgery

Leukocyte depletion during cardiopulmonary bypass has been demonstrated in animal experiments to improve pulmonary function. Conflicting results have been reported, however, with clinical depletion by arterial line filter of leukocytes at the beginning of cardiopulmonary bypass. In this study, we examined whether leukocyte depletion from the residual heart-lung machine blood at the end of cardiopulmonary bypass would improve lung function and reduce the postoperative inflammatory response. Thirty patients undergoing elective heart operations were randomly allocated to a leukocyte-depletion group or a control group. In the leukocyte-depletion group ( n = 20), all residual blood (1.2 to 2.1 L) was filtered by leukocyte-removal filters and reinfused after cardiopulmonary bypass, whereas in the control group an identical amount of residual blood after cardiopulmonary bypass was reinfused without filtration ( n = 10). Leukocyte depletion removed more than 97% of leukocytes from the retransfused blood ( p < 0.01) and significantly reduced circulating leukocytes ( p < 0.05) and granulocytes ( p < 0.05) compared with the control group. Levels of the inflammatory mediator thromboxane B 2 determined at the end of operation ( p < 0.05) were significantly lower in the depletion group than in the control group, whereas no statistical differences in interleukin-6 levels were found between the two groups. After operation, pulmonary gas exchange function (arterial oxygen tension at a fraction of inspired oxygen of 0.4) was significantly higher in the leukocyte-depletion group 1 hour after arrival to the intensive care unit ( p < 0.05) and after extubation ( p < 0.05). There were no statistical differences between the two groups with respect to postoperative circulating platelet levels and blood loss, and no infections were observed during the whole period of hospitalization. These results suggest that leukocyte depletion of the residual heart-lung machine blood improves postoperative lung gas exchange function and is safe for patients who are expected to have a severe inflammatory response after heart operations. (J T horac C ardiovasc S urg 1996;112:494-500)

Leukocyte-depleted blood components prevent platelet refractoriness in patients with acute myeloid leukemia.

Platelet refractoriness arising from HLA immunization develops in 20-50% of multitransfused patients with hematologic malignancies. We retrospectively analyzed the efficiency of leukocyte-depleted blood components in preventing refractoriness in 140 adult patients with acute myeloid leukemia (AML), treated according to a standardized cytostatic protocol. Sixty-eight patients received leukocyte-depleted (L-D) platelet concentrates (PCs) and red cells (RBCs), with fewer than 10(6) leukocytes per unit, and 72 patients received standard (STD) blood components. Two of 67 (3%) evaluable patients in the leukocyte-depleted group and 14 of 68 (21%) in the standard group became refractory during the median follow-up time of 229 days. Nine of 24 (37%) previously pregnant women in the STD group but none of 17 in the L-D group became refractory. Twenty patients were shifted during later treatment from L-D to STD PCs; none became refractory. Corrected platelet increments (CI) at 18 hours were higher after STD PCs (6.50 than L-D PCs (5.2), but more PCs and RBCs were transfused per patient in the STD group. It is concluded that effective leukocyte depletion prevents platelet refractoriness in patients with AML, even in those with previous immunization, and reduces the consumption of blood components.

Hemolytic transfusion reactions due to anti-e+f detectable only by nonstandard serologic techniques

Abstract A patient was transfused with a total of 14 units of red blood cells (RBCs) over 33 days (January 14 to February 15) at two hospitals. Febrile transfusion reactions were noted on three occasions, and hemoglobinuria was seen twice. Alloantibodies were not detected in a sample dated February 14, following a transfusion reaction, and this sample was referred to the North London Blood Transfusion Centre. Further samples were also obtained from before and after all transfusions at both hospitals. The patient’s RBCs typed as A, D+, probable Rh phenotype (cDE/cDE). The direct antiglobulin test was negative, and serum samples following the second transfusion were red/brown in color. Serologic investigations were inconclusive on all samples taken until February 13 (after the fourth transfusion). At this time, a weak anti-e reacting by manual polybrene technique and an anti-e+f reacting by two-stage papain technique were detected. The serum also contained potent HLA antibodies. The patient subsequently received leukocyte-depleted group A, cDE/cDE RBCs without any untoward effect. This case demonstrates the importance of a complete transfusion history and emphasizes that alloantibodies detectable only by nonstandard techniques can be clinically significant. Immunohematology 1994; 10:120–123.

Leucocyte Depletion and Prevention of Reperfusion Injury during Cardiopulmonary Bypass: A Clinical Study

This study evaluated the effects of leucocyte depletion on reperfusion injury during cardiopulmonary bypass in 26 patients who underwent coronary artery bypass graft. In 10 patients leucocytes were continuously separated from the circulating blood; in 16 leucocytes were undepleted. Leucocyte count and serum creatine phosphokinase activity (and that of its isoenzymes) were measured before and after aortic cross-clamping; in addition the cardiac index and required catecholamine dosage during the early postoperative period in the two patient groups were compared. Mean(s.d.) leucocyte counts immediately after surgery were 8622(2887) microliters-1 in patients who were leucocyte depleted and 12,175(5303) microliters-1 in controls (P < 0.05). Mean(s.d.) creatine phosphokinase activity in patients with leucocyte depletion was significantly lower than in controls (334(121) versus 821 (356) units l-1; P < 0.05) immediately after surgery. Moreover, mean(s.d.) catecholamine dosage was significantly less in the leucocyte-depleted group than in controls (1.1(1.9) versus 4.9(2.2) micrograms kg-1 min-1; P < 0.05), whereas the cardiac index was significantly higher (3.3(0.5) versus 2.3(0.4) l min-1 m-2; P < 0.05). These results suggest that, in the clinical setting, leucocyte depletion during cardiopulmonary bypass provides effective protection against reperfusion injury.

Leukocyte depletion results in excellent heart-lung function after 12 hours of storage

Extended preservation of the heart-lung bloc for 12 hours in a bovine model of heart-lung transplantation was achieved using donor core cooling, static hypothermic storage, and reperfusion on cardiopulmonary bypass with leukocyte-depleted (LD) blood. Orthotopic heart-lung transplantation was performed with (n = 4, LD group) or without (n = 4, control group) LD blood during cardiopulmonary bypass. Postoperative measurements of cardiopulmonary function were made at 2, 4, and 6 hours after reperfusion. Only 2 animals (50%) of the control group survived more than 2 hours, whereas all animals in the LD group survived the study period. Arterial oxygen tension on 100% oxygen was 535.63 ± 64.96 mm Hg and 146.45 ± 90.9 mm Kg in the LD and control groups, respectively, at 2 hours ( p < 0.5) and 524.3 ± 73.32 and 147.9 ± 255.67 mm Hg at 6 hours. Pulmonary artery systolic pressure-to-systemic pressure ratio was 0.49 ± 0.08 and 0.62 ± 0.35 at 2 and 6 hours in the LD group. Extravascular lung water was 17.81 ± 0.02 mL/kg (control group) and 11.28 ± 9.15 mL/kg (LD group) at 2 hours. At reperfusion, the mean neutrophil count was 27 ± 27 and 764 ± 635 × 10 9/L in the LD and control groups, respectively. This novel approach of leukocyte depletion during reperfusion after heart-lung preservation resulted in excellent cardiac and pulmonary protection.