Evaluation of the Pall RC100 leucocyte removal filters and the effect of air introduction on its performance

We evaluated the efficiency of Pall RC100 leucocyte removal filters in processing two units of concentrated red cells for transfusion. Our results show that the filter is very effective in processing the first unit. However, 32% (5/16) of the filters evaluated allowed a leak of substantial numbers of white cells towards the end of the transfusion of the second unit of blood. Air introduction experiments showed that as little as 2 ml of air in the filter may cause major deterioration of the filter function.

Improvement in rheumatoid arthritis following application of an extracorporeal granulotrap column, G-1

Patients with rheumatoid arthritis (RA) showed significantly (P < 0.01) increased numbers of granulocytes in their peripheral blood compared with normal donors and patients with osteoarthritis, and this finding correlated with interleukin-6 and C-reactive protein levels and active joint score. Then, 17 patients with RA were treated eight times in 4 weeks with a newly developed extracorporeal granulotrap column containing cellulose acetate beads (G-1 column). This column reduced granulocytes in the outflow blood by 50.2% compared with inflow counts. To evaluate the efficacy of G-1 therapy, 17 patients were followed for 12 weeks from the beginning of this therapy. The modified Lansbury index (LI) for monitoring RA activity significantly improved from a pretreatment mean score of 60.8% to a posttreatment score of 51.3%. The lowered scores were maintained up to 12 weeks after the initiation of therapy. Of the four LI items, tender and swollen joint scores showed the most significant improvement, with the tender joint score showing a particularly significant decrease throughout the study period. No serious side-effects were observed. These findings suggested that G-1 therapy was effective for RA.

Leukocytapheresis therapy with leukocyte removal filter for inflammatory bowel disease

Leukocytapheresis (LCAP) with a leukocyte removal filter was administered to 44 patients with inflammatory bowel disease (IBD), diagnosed as ulcerative colitis (UC) in 25 and Crohn's disease (CD) in 19. Clinical and blood examinations showed no side effects in any of the patients. During intensive therapy, clinical improvement was recognized in 21 of the 25 UC patients (84%), 8 of whom had an excellent response, and in 16 of the 19 CD patients (84.2%), 4 of whom had an excellent response. The clinical improvement continued throughout the maintenance therapy in 19 of the UC patients (76%) and in 12 of the CD patients (63.2%). In both the UC and the CD patients, flow cytometry study showed that those who had improved generally had high values for the percentages of HLADR+, HLADR+CD3+, HLADR+CD8+, and CD11a+CD8+ cells before the first LCAP, and that these values decreased to near the normal range after both intensive and maintenance therapy. In the patients who showed poor response, in contrast, the values had been at or near normal before the initial LCAP administration. The clinical improvement and the findings on flow cytometry suggest that LCAP exerts an immuno-modulatory effect and is an effective therapy for patients with IBD in whom conventional drug treatments have failed.

Comparison of Cobe Spectra and Haemonetics MCS-3P cell separators for peripheral blood stem cell harvesting

A prospective study was undertaken to compare the total nucleated cell (TNC), mononuclear cell (MNC), CD34+ cell, and CFU-GM yields of two different cell separators. A Haemonetics MCS-3P and a Cobe Spectra machine were used to leukapherese 10 patients with malignant diseases on 4 consecutive days after mobilization with G-CSF. All patients were harvested twice on each machine for a fixed period of time. The blood volume processed (10.47 vs 3.79 l, P < 0.001), MNC yield (2.66 vs 0.90 x 10(8)/kg; P < 0.001), MNC yield rate (1.66 vs 0.55 x 10(6)/kg/min; P < 0.001), MNC purity (81 vs 42%; P < 0.001), CFU-GM yield (18.1 vs 5.5 x 10(4)/kg; P = 0.001), and CFU-GM yield rate (11.27 vs 3.42 x 10(2)/kg/min; P = 0.001) were significantly higher with the Spectra. The CD34+ cell yields and yield rates were comparable. Although CFU-GM and MNC yields per unit blood volume processed were comparable for both machines, there was a trend for higher CD34+ yields per unit volume processed with MCS-3P. We conclude that Spectra is faster than MCS-3P with more blood processed per unit time resulting in higher cell yields, but yields per unit volume processed are comparable for both machines. The choice of machine for a given patient depends upon convenience, venous access and the time available.

Potential for reduction in morbidity and cost with total leucocyte control for cardiac surgery

The economics of health care in the USA and abroad has caused a shift in the focus on therapeutic interventions that transcend issues of safety and clinical efficacy. Now, cost justification is emerging as a major consideration to influence clinical practice. This brief review of the medical literature attempts to identify leucocyte-mediated adverse reactions that develop in open-hear surgery, quantify the costs incurred to manage such reactions and infer the savings that may accrue by controlling the burden of leucocytes presented to the open-heart surgical patient using commercially available leucocyte reducing filtration technology.

Use of the CS-3000 Plus to prepare apheresed blood cells for immunomagnetic positive cell selection

The Baxter CS-3000 Plus Blood Cell Separator was used to prepare progenitor cell components in a three-step process. The process was designed to remove platelets and plasma from a leukapheresis cell product before incubation with anti-CD34 monoclonal antibody (9C5) and to remove unbound monoclonal antibody after incubation. Fluorochrome-labeled cultured KG1a (CD34+) cells were added to the leukapheresis cell product (at 2% of total WBC) before CS-3000 processing to evaluate the CS-3000 process for preparing cells for immunomagnetic selection using the Isolex 300 (SA) Magnetic Separation system. Data were obtained using five leukapheresis products. Two percent of the nucleated cells were lost during the platelet reduction wash, and 67% of the platelets were removed. The amount of antibody initially added to the cells for incubation ranged from 3.9 to 7 mg (0.5 microgram/10(6) nucleated cells). The residual antibody in the cells after the antibody wash ranged from 11 to 40 micrograms. The antibody wash resulted in a 3% loss of nucleated cells and an additional 66% removal of platelets. The antibody-sensitized cells were then processed on the Isolex 300 (SA) system. The purity and yield of the Isolex KG1a cell product were 94% and 82%, respectively.

Cardiopulmonary bypass for adult patients: a survey of equipment and techniques

OBJECTIVES

The techniques and equipment used for cardiopulmonary bypass for adult cardiac surgery vary among institutions and may change over time. This study sought to document the changing patterns of practice.

DESIGN

Voluntary survey of meeting participants.

SETTING

13th Annual San Diego Cardiothoracic Surgery Symposium (February 1993).

PARTICIPANTS

There were 331 responses from perfusionists (79.5%), cardiac surgeons (11.2%), and anesthesiologists (6.3%). The majority of these participants were from institutions where more than 1,000 cardiac operations were performed annually.

MEASUREMENTS AND MAIN RESULTS

It was found that 91.5% of the respondents used membrane oxygenators currently, compared with 5% in 1982 (as reported in a previous survey). Over 80% of the institutions surveyed used some type of perioperative cell-salvaging technique. Arterial line filters were used by 92% of the respondents compared with 64% in 1982. Also, 80% of the respondents were aware of the availability of leukocyte-depleting filters.

CONCLUSIONS

The probable reasons for the increased utilization of membrane oxygenators and arterial line filters include less damage to the formed elements of blood, fewer gaseous microemboli, and better control of carbon dioxide elimination and oxygenation. The authors anticipate that future surveys will document increased use of leukocyte-depleting filters because of the literature implicating neutrophils as mediators of tissue destruction in various disease processes, including myocardial reperfusion injury.

Leukocytapheresis therapy, performed with leukocyte removal filter, for inflammatory bowel disease

Leukocytapheresis (LCAP), performed with a leukocyte removal filter, was administered five times, at 1-week intervals, for 5 weeks of intensive therapy and five times, at approximately 1-month intervals, for approximately 5 months of maintenance therapy, to 13 patients with inflammatory bowel disease (IBD) diagnosed as ulcerative colitis (UC) in 8 and Crohn's disease (CD) in 5. Clinical and blood examinations showed no side effects in any of the patients. During the intensive therapy, excellent or moderate clinical response was recognized in 11 of the 13 patients (84.6%), of whom 6 had a dramatic response; the excellent or moderate clinical response continued throughout the maintenance therapy in 8 of the patients (61.5%). Flow cytometry showed that the patients who had improved generally had high values for percentages of HLADR+, HLADR+CD3+, and HLADR+CD8+ cells before the first LCAP, and that these values and the C-reactive protein levels and erythrocyte sedimentation rates had decreased to the normal range by the end of both intensive and maintenance therapy. In the patients who showed poor response, in contrast, all the above values had been at or near normal before the initial LCAP administration. The clinical improvement in the absence of any additional medical treatment suggests that LCAP has the capacity to influence the causal mechanism(s) of IBD and that IBD is strongly associated with the cell-mediated immune response.

Flow cytometry quantification of CD34+ cells and other leukocyte subpopulations in frozen-thawed blood cell suspensions: investigation of a new teflon container for cryopreservation of hematopoietic progenitor cells

BACKGROUND

Cryopreservation is the only available method for the long-time maintenance of blood cells. The present study was designed to prove: (i) the reliability of multiparameter flow cytometry (MFC) for estimation of CD34+ cells in frozen-thawed cell suspensions and (ii) the acceptability of a new teflon container for the cryopreservation of hematopoietic progenitor cells.

MATERIALS AND METHODS

Each of 15 ABO-compatible buffy coats (BC) were pooled, and mononuclear cells (MNC) were then separated with the Fresenius AS 104 device (n = 10). MNC harvested by apheresis were then divided into 2 portions and transferred pairwise into either the new Fresenius or into Gambro cryopreservation containers. Paired samples were frozen at controlled rates (9% DMSO final concentration) and stored at -196 degrees C in liquid nitrogen for 2 weeks. Leukocyte, MNC and differential blood counts and proportions of CD3+, CD4+, CD8+, CD14+ and CD34+ cells were assessed from the pooled BC, the apheresis products, and the frozen-thawed samples. Methyl cellulose culture assays as well as trypan blue viability staining were also carried out.

RESULTS

The mean content of the divided apheresis products was 4.9 x 10(9) leukocytes with 86% MNC, 6.89 x 10(6) CD34+ cells, 2.1 x 10(5) granulocyte-macrophage colony-forming units (CFU-GM) and 7.1 x 10(5) erythroid burst-forming units (BFU-E). As expected, there were virtually no granulocytes after freezing in both types of container. The corresponding mean cell content was as follows: 6.3 x 10(6) CD34+ cells, 2.5 x 10(5) CFU-GM, and 8.1 x 10(5) BFU-E in Fresenius containers, and 6.1 x 10(6) CD34+ cells, 1.3 x 10(5) CFU-GM, and 7.7 x 10(5) BFU-E in Gambro containers. The mean MNC viability of the samples frozen in Fresenius was 81.5% and 82.7% in the Gambro containers. MFC was found to compare with stained smear differentials. CD34+ cell counts correlated with CFU-GM (0.69, p = 0.03) and BFU-E (0.63, p = 0.02) colony formation.

CONCLUSIONS

The study reported here revealed no significant differences between the 2 types of storage containers. The new Fresenius teflon container could thus be recommended for cryopreservation of hematopoietic progenitor cells. MFC provided reliable data on CD34+ cell content and leukocyte subset composition of the frozen-thawed cell suspension.

Preparation of white cell-reduced red cells by filtration: comparison of a bedside filter and two blood bank filter systems

BACKGROUND

Concern has been raised about the quality of white cell (WBC)-reduced red cells (RBCs) obtained by bedside filtration. The bedside performance and workload of a routine bedside filter have been compared to the laboratory performance and workload of two blood bank filter systems.

STUDY DESIGN AND METHODS

Buffy coat-depleted saline-adenine-glucose-mannitol (SAGM) RBCs (90 units) were prepared. Thirty units were filtered with each of the two blood bank filter systems, and 30 units were filtered (but not transfused) with the bedside filter in a clinical department after 8 to 24 days of storage. The RBCs lost and the postfiltration WBC content (Nageotte chamber) were determined for all filtered units, and the workload associated with filtration by each of the filter systems/filter was assessed. Units with a postfiltration content of > or = 2 x 10(6) WBCs were regarded as filtration failures.

RESULTS

Four (13%) of the 30 units filtered at the bedside were filtration failures, compared to no failures with either of the blood bank filter systems. In addition, the median WBC content (0.14 x 10(6)) of the units filtered at the bedside (2 units/filter) was significantly higher than that of the units filtered in the blood bank (0.05 x 10(6)). The RBC loss was significantly higher with the filter systems than with the bedside filter, provided 2 units per filter were processed with the latter. The timed workload of the filter systems was 45 to 75 minutes per 12 units, which was similar to the time required for bedside filtration.

CONCLUSION

Bedside filtration of 2 units of stored buffy coat-depleted SAGM RBCs per filter resulted in a higher incidence of filtration failure and higher postfiltration WBC content than did laboratory filtration of 1 unit of fresh buffy coat-depleted SAGM RBCs per filter with either of two blood bank filter systems.

A comparison of peripheral blood stem cell apheresis using the Fenwal CS3000 Plus and COBE Spectra

We have compared the leukapheresis products collected on the Fenwal CS3000 Plus and COBE Spectra in a well-controlled patient population. While statistically significant differences were found, i.e. in product hematocrit, volume, number of granulocytes and platelets collected, these are not felt to be physiologically important. Similar efficiency in collecting mononuclear cells and colony forming unit assay results indicate that each instrument is capable of harvesting hematopoietic progenitor cells from peripheral blood.

Double-lumen inferior vena cava catheters for peripheral stem cell apheresis and transplantations

No previously published studies have described double-lumen hemodialysis/apheresis catheters for use with continuous-flow apheresis collection of peripheral stem cell (PSC). We prospectively evaluated experiences with these catheters during both PSC collection and transplantation. Because of previously-described successful experiences with single-lumen apheresis catheters placed in the inferior vena cava, all catheters evaluated in this study were placed in this anatomic location. Our experience demonstrated high rates of thrombotic occlusion (65%) and catheter-related infections (15%). This method of access should not be considered optimal in its present state of use. Further investigation into preferred catheter design, anatomic location, and thrombosis prophylaxis during continuous-flow apheresis is warranted.

Evaluation of leukocyte-depleted terminal blood cardioplegic solution in patients undergoing elective and emergency coronary artery bypass grafting

Leukocyte depletion at reperfusion may have a role in myocardial protection when combined with terminal cardioplegia. We applied this method in a selected group of 68 patients with coronary artery bypass grafting either for elective surgical procedures (n = 38) or emergency surgical procedures with the use of a preoperative intraaortic balloon pump (n = 30) because of developing acute myocardial infarction. Basic cold potassium crystalloid cardioplegic solution was used. During delivery of leukocyte-depleted terminal cardioplegic solution, warm arterial blood delivered from cardiopulmonary bypass was passed through a leukocyte removal filter, mixed with potassium crystalloid cardioplegic solution, and administered to the aortic root for the first 10 minutes of reperfusion. Patients were randomized into three groups for reperfusion: whole blood, terminal cardioplegic solution, and leukocyte-depleted terminal cardioplegic solution reperfusion groups. In elective coronary artery bypass grafting, no significant difference was found in the clinical data. However, in emergency coronary artery bypass grafting, the leukocyte-depleted terminal cardioplegic solution group (n = 10) showed significantly lower peak creatine kinase MB levels (leukocyte-depleted terminal cardioplegic solution versus terminal cardioplegic solution versus whole blood: 27 +/- 11, 56 +/- 13, 74 +/- 18, respectively; p < 0.05) and maximum dopamine doses required at the weaning of cardiopulmonary bypass (6.3 +/- 1.1 versus 11.2 +/- 3.3 versus 9.2 +/- 2.2; p < 0.05) than did the terminal cardioplegic solution (n = 10) and whole blood groups (n = 10). Moreover, the leukocyte-depleted terminal cardioplegic solution group showed significantly lower difference of malondialdehyde between arterial and coronary sinus blood (0.15 +/- 0.09 versus 0.36 +/- 0.06 versus 0.06 +/- 0.12 nmol/ml, p < 0.05) than did the terminal cardioplegic solution or whole blood groups. These results showed that leukocyte-depleted terminal blood cardioplegic solution may have a role in attenuating reperfusion injury in patients with critical conditions such as preoperative myocardial ischemic injury.

The effects of using a leukocyte removal filter during cold blood cardioplegia

During myocardial ischemia, neutrophils and platelets exert negative effects on the myocardium. In this study, we used a leukocyte removal filter during cardioplegia, and investigated its effect on myocardial damage during reperfusion by measuring the plasma levels of granulocyte components, platelet components, and cardiac enzymes [creatinine phosphokinase (CK) and creatinine phosphokinase myocardial band (CK-MB)] in 24 patients who underwent cardiopulmonary bypass. The patients were divided into two groups of 12 according to whether or not a filter was placed in the cardioplegic route. Blood samples were drawn directly from the coronary sinus before aortic cross clamping, and at 1, 5, and 15 min after declamping. Group F, which had the filter, showed better cardiac enzyme and lipid peroxidation results than group N, which did not. The results of this study suggest that the application of a filter during cold blood cardioplegia may reduce myocardial damage.

Activation of plasma components by leukocyte removal filters

The technique of leukocyte filtration has been introduced into cardiac surgery to reduce leukocyte mediated reperfusion injury. When autologous whole blood (WB) is used as filtrate, it is more likely to be activated by the filter material than are banked red blood cell concentrates (RCC), because of its richness in plasma components. This study was designed to compare the activation of plasma components during leukocyte filtration from WB (n = 10) taken from the heart-lung machine, with RCC (n = 10) obtained from the blood bank. Leukocyte filters made from either cellulose acetate or polyester were used. Blood samples were taken simultaneously from the inlet and outlet of the filter after filtration of either 700 ml of WB or 350 ml of RCC. Results indicated that the complement cascade was activated, as reflected by the increase of C3a and C5a during filtration of WB by filters made from cellulose acetate. In contrast, there was no significant increase of C3a and C5a during filtration of RCC. The clotting system, indicated by fibrinopeptide A, and the fibrinolytic system, indicated by fibrinogen degradation products, were not activated during leukocyte filtration. These data suggest that it is the WB taken from the heart-lung machine rather than the RCC from the blood bank that is being activated during leukocyte filtration. Thus, careful selection of filter material is important for leukocyte filtration of autologous whole blood during cardiac surgery.

[High-dose chemotherapy, G-CSF and the use of peripheral blood progenitor cells in patients with poor-prognosis neuroblastoma]

In the past decade there has been an increasing use of high dose of chemo-radiotherapy in the treatment of poor prognosis solid tumors of childhood. The autologous bone marrow transplantation is the most used technique for circumventing the infectious and haemorrhagic complications occurring in the prolonged period of myelotoxicity. The faster recovery assured by the peripheral blood progenitor cells (PBPC) makes this procedure an attractive alternative. The advent of new apheretic modalities and the use of combinations of active antineoplastic drugs with various growth factors, such as G-CSF, GM-CSF and IL-3, has allowed to collect and concentrate the mononuclear fraction of peripheral blood leukocytes. The optimal timing for the collection is a crucial point and the utilization of flow cytometry for the determinations of circulating CD34+ cells in the peripheral blood is so far the best indicator for successful apheresis. The authors describe their experience in 16 children affected by poor prognosis neuroblastoma who had undergone high dose chemotherapy followed by G-CSF administration and PBPC collection. The details of apheretic techniques and the characteristics of conditioning regimen and haematologic recovery after PBPC reinfusion are also presented.

[The effects of a leukocyte removal filter during cold blood cardioplegia]

During myocardial ischemia neutrophils and platelets exert negative effects on the myocardium. We used a leukocyte removal filter during cardioplegia and investigated it's effect on myocardial damage during reperfusion. Plasma levels of the granulocyte components, the platelet components, and cardiac enzyme (CK-MB) were evaluated in 14 patients undergoing cardiopulmonary bypass. Blood samples were drawn directly from the coronary sinus before aortic cross clamping and 1, 5, and 15 minutes after unclamping. The group which had the filter in the cardioplegic route to eliminate the neutrophils and platelets showed better results than the group without the filter on cardiac enzyme and lipid peroxidation (LPO). In conclusion the application of the filter during cold blood cardioplegia effectively on enzymatically reduces myocardial damage during reperfusion.

Evaluation of the Fresenius cell separator AS 104 for harvesting peripheral blood stem cells in pediatric patients

In a single institution trial we carried out 35 peripheral blood stem cell harvesting procedures in 12 children with advanced malignancies to evaluate the procedure's safety and the collection efficiency of the Fresenius blood cell separator AS 104 in a pediatric population. Despite a significant mean decrease of 21% (+/-8%) in systolic blood pressure after starting the procedure, all children tolerated leukapheresis without any adverse reaction. After termination of leukapheresis there was a significant decrease of all determined hematological parameters, as compared with pre-harvest values. The mean mononuclear cell recovery was 64% (+/-26%), and in 25/35 (71%) harvesting procedures the minimum progenitor number required for safe autografting could be obtained by one single leukapheresis. We conclude that the Fresenius AS 104 blood cell separator provides a high cell yield and is a safe device for leukapheresis in pediatric patients.

[Large volume lymphocytapheresis for the collection of peripheral stem cells]

We performed 29 large-volume leukaphereses of 20 patients for collection of peripheral blood stem cells. All patients have been pretreated with cytokines after chemotherapy. In 9 patients with precounts of > or = 3 x 10(9) mononuclear cells/l we achieved a sufficient transplantation doses with one LVL. If the MNC precount was < or = 3 x 10(9)/l we had to perform more than one LVL. On 16 patients we compared a standard apheresis procedure with the LVL procedure. It seems that especially patients with a lower MNC precount can profit from LVL. From patients with higher MNC precounts we harvested the double amount of MNCs, from patients with lower MNC precounts the triple amount.

Technical aspects of buffy coat removal from whole blood and those of platelet production from single buffy coat units

Technical aspects of buffy coat removal and those of platelet production from the buffy coat were studied using the so-called Amsterdam technique. A long stomach clamp physically separates the buffy coat from erythrocyte concentrate. A better removal of platelets and leukocytes was obtained when blood stored overnight was processed vs. fresh blood. As 71.4 +/- 16.4% of leukocytes was removed from blood stored overnight, it resulted in a mean leukocyte content of 0.84 +/- 0.52 x 10(-9) of the erythrocyte concentrate. The haematocrit of the single buffy coat units have an essential impact on platelet production from buffy coat. A haematocrit of less than 30% seems to be preferable with a volume over 100 ml. The leukocyte contamination of the platelet concentrate is less when it is produced from blood stored overnight.