The logics of leukocytapheresis as a natural biological therapy for inflammatory bowel disease

Ulcerative colitis (UC) and Crohn's disease (CD) are debilitating idiopathic inflammatory bowel diseases (IBDs) with symptoms that impair ability to function and quality of life. The aetiology of IBD is inadequately understood and, therefore, drug therapy has been empirical instead of based on sound understanding of the disease mechanisms. This has been a major factor for poor drug efficacy and treatment-related side effects that often add to disease complications. The development of biologicals, notably infliximab, to block TNF-alpha reflects some progress, but there is major concern about their side effects and lack of long-term safety and efficacy profiles. However, IBD by its very nature is exacerbated and perpetuated by inflammatory cytokines, including TNF-alpha, IL-6 and IL-12, for which activated peripheral blood lymphocytes, monocytes/macrophages and granulocytes are major sources. Hence, activated leukocytes should be appropriate targets of therapy. At present, three strategies are available for removing excess and activated leukocytes by leukocytapheresis: centrifugation, Adacolumn and Cellsorba. Centrifugation can deplete lymphocytes or total leukocytes, whereas Adacolumn selectively adsorbs granulocytes and monocytes together with a smaller fraction of lymphocytes (FcgammaR- and complement receptor-bearing leukocytes), and Cellsorba non-selectively removes all three major leukocyte populations. Efficacy has ranged from 'none' to an impressive 93% together with excellent safety profiles and downmodulation of inflammation factors. Furthermore, leukocytapheresis has shown strong drug-sparing effects and reduced the number of patients requiring colectomy or exposure to unsafe immunosuppressants, such as cyclosporin A. Leukocytapheresis removes from the body cells that contribute to IBD and, therefore, unlike drugs, it is not expected to induce dependency or refractoriness.

CD14+ cell collection in non-cytokine-stimulated donors with the COM.TEC cell separator

BACKGROUND

The COM.TEC cell separator (Fresenius Hemocare), equipped with the MNC program (single-stage chamber) and the PBSC-LYM program (dual-stage chamber), was evaluated for CD 14+ cell collection regarding cell yields, collection efficiencies (CEs), and the content of residual cells in harvests.

STUDY DESIGN AND METHODS

Twenty-four non-cytokine-stimulated donors underwent 5-L mononuclear cell (MNC) collections on the COM.TEC device to compare both programs. Two software versions (v02.03.05 vs. v 03.00.04) were investigated for optimization of the CD 14+ cell collection process. Blood counts of donors and products were analyzed for CD 14+ cells by flow cytometry and for platelets (PLTs), white blood cells, and red blood cells (RBCs) by a blood cell counter.

RESULTS

In 5-L collections, the MNC program resulted in high CEs (83+/- 23%) and yields (1.2 x 10(9)+/- 0.6 x 10(9) per unit) of CD 14+ cells, but the products showed high residual PLTs. The use of a dual-stage chamber in the PBSC-LYM program produced a low content of residual PLTs (0.7 x 10(11) +/- 0.3 x 10(11) per unit) and RBCs but failed to reach a target of 1 x 10(9) CD 14+ cells. Modulated light to stabilize the buffy-coat detection by the interface monitor significantly improved CD 14+ cell enrichment. By use of the PBSC-LYM program, higher centrifuge velocity (1700 rpm [382 x g] vs. 1500 rpm [297 x g]) improved significantly CD 14+ cell yields (0.7 x 10(9) vs. 0.5 x 10(9) cells).

CONCLUSION

A pure CD 14+ cell product with low numbers of residual cells was obtained by the PBSC-LYM program, which could be useful for good manufacturing practice-conformed production within closed systems. The MNC program offers the collection of high CD 14+ cell yields with excellent CEs but also high residual PLT counts.

Clinical impact of a new automated system employed for peripheral blood stem cell collection

At the moment, PBSC collections can be performed using semi-automated or automated cell separator devices. The automated methods offer the advantages of a decreased working load for dedicated personnel and high standardization of the collection procedure. Herein we report our single institutional experience in 80 PBSC collections employing the new automated COM.TEC Fresenius autoMNC program that provides the ability to predict the total number of CD34(+) cells collected, based on the pre-leukapheresis CD34(+) cell count in peripheral blood. Fourty-eight patients and 21 healthy donors were mobilized with chemotherapy + G-CSF or G-CSF alone, respectively. Eighty leukapheresis collections were performed starting with a CD34(+) cell count in peripheral blood at least of 20/microL. Collection parameters and related side effects were evaluated. The mean CD34(+) cell collection efficiency in patients and donors was 81.8% (sd 27.6) and 95.1% (sd 15.6), respectively. The mean difference between real and predicted CD34(+) cells was +30.2% (sd 92.9) for patients and +4.6% (sd 30.3) for donors. The mean leukapheresis bag volume was 240.7 ml (sd 67.3) and 310.3 ml (sd 86.8) with a mean HCT of 10.9% (sd 34.4) and 9.2% (sd 3.9) for patients and donors, respectively. The automated PBSC collection with the new program COM.TEC Fresenius autoMNC demonstrated a very high CD34(+) cell collection efficiency. Moreover, the ability to predict the CD34(+) cell yield permits improved management of the leukapheresis collection, with the only disadvantage of larger leukapheresis volume and higher hematocrit.

Developments in the apheresis procedure for the treatment of inflammatory bowel disease

Initially used to treat rheumatoid arthritis, nonselective therapeutic leukocytapheresis was applied to the treatment of inflammatory bowel disease (IBD) as early as the 1980s. Since then, the process has been further refined and 2 blood perfusion systems using membrane filtration are presently employed in Japan and Europe for the selective removal of leukocytes in patients with IBD: Cellsorba is a column of polyethylenephtarate fibers that captures lymphocytes and granulocytes, and Adacolumn is a column of cellulose acetate beads that selectively adsorb granulocytes and monocytes. These systems overcome the limitations of centrifugation. Leukocytapheresis has been shown to exert an overall anti-inflammatory effect, as peripheral leukocytes demonstrated a diminished capacity to produce inflammatory cytokines such as tumor necrosis factor-alpha, interleukin (IL)-1, IL-6, IL-8, and IL-1beta. In addition, down-regulation in the expression of adhesion molecule L-selectin and a shift toward a more immature granulocyte phenotype were observed in the peripheral blood. The safety and beneficial therapeutic effect of leukocytapheresis in IBD are being investigated further.

Prospective randomised comparison of the COBE Spectra version 6 and Haemonetics MCS+ cell separators for hematopoietic progenitor cells leucapheresis in patients with multiple myeloma

A randomised crossover trial of two separators was undertaken to compare the mononuclear cell, CD34(+) cell and CFU-GM yield, in patients (<61 years) with previously untreated symptomatic multiple myeloma. After first-line therapy, all patients received mobilising chemotherapy (cyclophosphamide 4 g/m(2)) and daily G-CSF. The first leucapheresis was performed on the first day the peripheral blood absolute CD34(+) cell count was > 20 cells/microl. All patients underwent 2 leucaphereses on consecutive days. The patients were randomised to undergo either the first or second leucapheresis using the COBE Spectra. The target duration of the procedure on the COBE Spectra was 2 total blood volumes, and for the Haemonetics MCS(+) it was 20 cycles with four recirculations. Between September 2003 and March 2005, 60 patients were entered in the study. COBE Spectra version 6 processed significantly larger volumes of blood than the Haemonetics MCS(+) (8,845 and 5,680 ml, respectively, P < 0.01). The absolute yield of mononuclear cells (2.1 vs. 1.5 x 10(8)/kg, P = 0.04), CFU-GM (11 vs. 3 x 10(4)/kg, P = 0.01) and CD34(+) cells (3 vs. 1.7 x 10(6)/kg, P = 0.02) were all significantly higher with the COBE Spectra version 6, as were the yields per unit volume of blood processed. In conclusion, our study shows that COBE Spectra Version 6 is faster and has a better yield than the Haemonetics MCS(+), in patients with multiple myeloma.

Preliminary data on the use of apheresis in inflammatory bowel disease

In patients with inflammatory bowel disease (IBD), centrifugation has been attempted to remove leukocyte components from whole blood; however, the use of selective filters has proved to result in more active modification of cellular immunity in that 4 times as many white blood cells are removed, which may result in a greater therapeutic effect. Selective apheresis for treatment of IBD, in particular ulcerative colitis (UC), has been used in Japan and some European countries for several years; pilot studies with Adacolumn, a selective therapeutic granulocyte/monocyte apheresis device, in patients with IBD have recently been completed in the United States with favorable results. Unlike conventional pharmacological treatments, selective apheresis may be associated with a relatively low rate of adverse events. Multiple studies have suggested that selective apheresis may be of benefit as a steroid-sparing treatment. In an unblinded randomized trial in 69 steroid-dependent patients with active UC randomized to selective apheresis with Adacolumn or an increased dose of prednisolone, 83% of patients receiving Adacolumn achieved remission compared with 65% of those receiving an increased dose of prednisolone. In another uncontrolled study of 60 patients with active UC, treatment with Adacolumn selective apheresis enabled nearly 70% of steroid-dependent patients to discontinue prednisolone. An unblinded randomized controlled trial of a different selective apheresis device (Cellsorba) versus high-dose prednisolone in patients with active UC showed a greater therapeutic effect (74%) than high-dose prednisolone (38%) and lower frequency of adverse effects (24% versus 68%).

Whole-blood leukodepletion filters as a source of CD34+ progenitors potentially usable in cell therapy

BACKGROUND

Used leuko-depletion filters (LDFs), containing billions of white blood cells (WBCs), are discarded. Because the steady-state blood contains low quantities of stem and progenitor cells that are retained in LDFs, the viability and the functional properties of mononuclear cells (MNCs) and CD 34+ cells recovered from LDFs were investigated.

STUDY DESIGN AND METHODS

WBCs were recovered from LDFs by use of a closed system. MNCs and CD 34+ cells were isolated from freshly LDF-recovered WBCs or after their overnight incubation. The CD 34+ cells were enumerated, as well as the number of colony-forming unit (CFU)-granulocyte-macrophage, burst-forming unit-erythroid, and CFU-Mixed. The expansion in clinical-scale volume cultures (serum-free medium plus stem cell factor, granulocyte-colony-stimulating factor, and megakaryocyte growth and development factor) was performed starting from MNCs, freshly isolated CD 34+ cells, and CD 34+ cells isolated after overnight incubation of WBCs. The erythroid, megakaryocytic, eosinophilic, and monocyte-myelocytic lineage differentiation of LDF-recovered CD 34+ cells was challenged in liquid cultures by adding relevant cytokines.

RESULTS

Nearly 450 x 10(3) viable CD 34+ cells were recovered per LDF. These cells exhibit unimpaired colony-forming ability. It is possible to expand these cells ex vivo, but their response to cytokines is different compared to mobilized peripheral blood and cord blood CD 34+ cells. Thus, further work is necessary to optimize their ex vivo expansion. These cells give rise to the mature cells and precursors of erythroid, megakaryocytic, eosinophilic, and monomyelocytic lineage in liquid cultures.

CONCLUSION

MNCs and CD 34+ cells recovered from the LDFs exhibit unimpaired functional capacities. Recent development of ex vivo technologies for expansion, retro-differentiation, and differentiation reinforces the value in cell therapy of these LDG-recovered peripheral blood progenitor cells that are routinely discarded.

Leukapheresis for the extraction of monocytes and various lymphocyte subpopulations from peripheral blood: product quality and prediction of the yield using different harvest procedures

BACKGROUND AND OBJECTIVES

Leukapheresis of non-mobilized healthy donors is performed to harvest monocytes and lymphocyte subpopulations for use in various therapeutic regimens. In this methodological study, we compared two different leukapheresis programs, using equivalent volumes of processed blood over similar processing periods, to determine the influence of the procedures on the donor peripheral blood count and to establish the procedure that yields the highest quality product.

MATERIALS AND METHODS

The target variables obtained in 41 healthy blood donors who underwent short-term leukapheresis (80-105 min) were retrospectively compared. Twenty-one volunteers were processed on a COBE Spectra machine at the MNC setting and 20 volunteers were processed at the AutoPBSC setting. Data were collected on pre- and postleukapheresis samples and on the product.

RESULTS

AutoPBSC and MNC procedures resulted in a decrease of haemoglobin (5-7%), platelets (17-20%), monocytes (22%) and lymphocytes (23-27%), but not of granulocytes in peripheral blood. Both procedures produced nearly identical leucocyte and lymphocyte yields. AutoPBSC products contained a greater number of granulocytes, monocytes and red cells, but fewer platelets. The preleukapheresis values correlated with the yields for monocytes, T-helper and T-suppressor cells, B-lymphocytes and natural killer cells, but not for granulocytes or platelets.

CONCLUSIONS

Leukapheresis is a safe and efficient procedure for collecting large numbers of peripheral blood monocytes and different lymphocyte populations from non-mobilized donors. The two programs yield comparable leucocyte harvests. Based on our results, yields can be predicted from the peripheral cell counts.

Pilot clinical study of Adacolumn cytapheresis in patients with systemic lupus erythematosus

The aim of this study is to investigate the clinical effects of cytapheresis using the Adacolumn system (selective removal of circulating monocytes and granulocytes by means of an extracorporeal type column) in patients with active systemic lupus erythematosus (SLE). An open uncontrolled multicenter pilot study was conducted in 18 SLE patients who were showing a SLEDAI score of 8 or more under conventional medication. Patients with lupus nephritis (>class 1, WHO classification) were excluded. Extracorporeal cytapheresis with the Adacolumn system was administered once a week for five consecutive weeks. The efficacy of the treatment was evaluated using the SLEDAI for 10 weeks after the first cytapheresis session. The median SLEDAI decreased from 16 at baseline to six at week 11 (10 weeks after the first apheresis) (p<0.001). Significant improvements in musculoskeletal and dermal systems were observed. Arthritis and alopecia were present in 14 and nine patients at baseline and this number decreased to five and one patients, respectively by week 11. Three mild and one moderate adverse events out of the 42 reported events were judged 'probably related' to the treatment; no serious adverse events were reported. Selective removal of monocytes and granulocytes from the blood in an extracorporeal circulation system was associated with clinical improvement in this small series of patients with SLE. Since this approach seems not to have the disadvantages of pharmacological immunosuppression, further controlled studies of Adacolumn cytapheresis are warranted in SLE.

Two red blood cell units collected in SAG-M additive solution with the ALYX component collection system

The first protocol available for the new ALYX component system (Baxter Healthcare Inc.) allows automated collection of two Red Blood Cell (RBC) units from one donor. The primary objective of our evaluation was to assess donor safety, comfort and to check the quality of blood products collected. 30 procedures were performed on eligible donors according to French best donation practices. Eligibility criteria were defined in order to ensure a post donation hemoglobin concentration of 11 g/dL minimum. Pre donation ferritin level was also checked. 360 ml of absolute RBC were collected from each donor. Donors physiological parameters and haematological profile were measured immediately before and after donation. Adverse events and donors were observed during the procedure and followed daily during 5 days after donation. Hemolysis in RBC was followed until of shelf life (<0.8% on 42 days storage). The evaluation of different parameters during storage show no difference if we compare with the manual technique. The concentration of hemoglobin is good and all ou concentrates are conform. No serious adverse effects were reported during and after donation. All donors confirmed they would agree to donate 2 RBC units again with this system. We have seen a good quality of RBC products. This evaluation indicates that 2 RBC donation is feasible on the ALYX system, comfortable and safe for eligible donors.

Leukocytapheresis in ulcerative colitis: results of a multicenter double-blind prospective case-control study with sham apheresis as placebo treatment

OBJECTIVE

Leukocytapheresis (LCAP) is a method of therapeutic apheresis that removes peripheral leukocytes. Previous studies showed that in patients with ulcerative colitis (UC), LCAP was more effective than high-dose steroid therapy, and it had few adverse effects. We investigated LCAP in a multicenter study using active and sham devices in a double-blind study in order to elucidate the placebo effect of extracorporeal treatment including anticoagulant medication.

METHODS

Twenty-five patients with active UC of severe or moderately severe grade were enrolled and assigned to the active group or the sham group. Six patients were excluded from the study and 19 (10 in the active group and nine in the sham group) were evaluated. LCAP (treatment using an active device or a sham device) was performed once a week for 5 wk, followed by two additional sessions during the next 4 wk at 2-wk intervals. Steroids and other medications were continued at the same dosage for 4 wk, which included a 2-wk pre-observation period and the first 2 wk after the start of the LCAP treatment. New medications or increase in the dosage of previous medication were prohibited until evaluation was conducted.

RESULTS

The clinical activity index (CAI) value of UC, indicated that the active group showed a significantly greater improvement (80%, 8/10) than the sham group (33%, 3/9; p<0.05). Adverse effects were observed in five patients (one in the active group and four in the sham group). None of these effects was severe and none of the sessions was terminated as a consequence of the adverse effects.

CONCLUSION

The results confirmed that LCAP is a safe and effective therapeutic option for patients with active UC.

[Comparison of the effect of Cobe Spectra and Fenwal CS 3000 plus blood cell separators in collection of peripheral blood stem cell components]

To evaluate the hematopoietic stem/progenitor cell apheresis effect of Cobe Spectra (Version 6.1) and Fenwal CS 3000 Plus cell separators, fourty-two procedures on twenty donors using Cobe Spectra cell separator and twenty-two procedures on sixteen donors using Fenwal CS 3000 Plus cell separator were retrospectively analyzed. The number of CD34(+) cells collected, the collection efficiency (CE) of CD34(+) cells and the contaminations of red blood cell and platelet in the stem/progenitor cell products of two devices were compared. The results showed that there were no significant differences in the total number of CD34(+) cells collected and the CD34(+) cell CE between the two devices. There were positive correlations between the count of peripheral blood cells including leukocyte, monocyte, hematopoietic progenitor cell and CD34(+) cell after mobilization and the total number of CD34(+) cells collected. The stepwise multiple variable analyses revealed the peripheral blood stem/progenitor cell count emerged as the only significant independent predictive factor for CE. A negative correlation was seen between the peripheral blood monocyte count and the CD34(+) cell CE for the Fenwal CS 3000 Plus. The Fenwal CS 3000 Plus product contained more red blood cells than that of the Cobe Spectra. The decrease in the peripheral platelet count after Fenwal CS 3000 Plus apheresis was also greater. It is concluded that collection efficacy of Cobe Spectra (Version 6.1) and Fenwal CS 3000 Plus was similar. Cobe Spectra shall be used preferably to assure higher CD34(+) cell CE at a high peripheral blood monocyte count. The Cobe Spectra cell separator is better for the donors with mismatched blood type and the donors with thrombocytopenia.

Mononuclear cell variability and recruitment in non-cytokine-stimulated donors after serial 10-liter leukapheresis procedures

BACKGROUND

We introduced monitoring of mononuclear cell (MNC) counts to obtain enhanced donor control and a stable quality of MNC products, because there are limited data available about blood donors after serial leukapheresis (LP) procedures.

STUDY DESIGN AND METHODS

In a prospective paired study, 13 male healthy blood donors underwent 10-L LP procedures performed on two apheresis devices by use of two MNC program settings (COBE Spectra, Gambro BCT, SF 250 vs. SF 500; and AS.TEC 204, Fresenius Hemocare, CP 129 vs. CP 194). Donors' pre- and postdonation MNC counts were analyzed by fluorescence-activated cell sorting.

RESULTS

After each 10-L LP procedure, a transient decline (p < 0.05) of CD14+ monocyte and platelet counts appeared in donors. Loss of donors' CD3+ T cells, CD19+ B cells, and CD16+56+ natural killer (NK) cells during MNC collection was partly compensated by cell recruitment. The MNC recruitment factor (RF) seems to be higher with high-yield MNC program settings. Negative correlations (p < 0.01) were noticed between predonation counts and RFs of CD3+ T cells and CD16+56+ NK cells. Four serial 10-L LP procedures did not result in long lasting MNC depletion for donors.

CONCLUSION

MNC recruitment seems to depend on MNC program settings and collected cell yields. Low MNC counts could result in high cell recruitment that may contribute to stable collection results to some degree. Nevertheless, there seems to be a considerable individual variation of MNC recruitment in donors that should be investigated in more detail.

Safe And Efficient Collection of Cytokine-Mobilized Peripheral Blood Cells From Cynomolgus Monkeys (Macaca fascicularis) with Human Newborn-Equivalent Body Weights

Hematopoietic stem cells in bone marrow can be mobilized into peripheral blood by cytokine administration. Cytokine-mobilized peripheral blood stem cells are of great use in clinical applications. We previously established a modified procedure for the collection of cytokine-mobilized peripheral blood cells from rhesus monkeys (Macaca mulata) using a commercially available apparatus originally developed for human subjects. In this study, we examined the efficacy and safety of this method with even smaller macaques, cynomolgus monkeys (Macaca fascicularis), which are equivalent to human newborns in body weight (mean = 3.3 kg). Using the manufacturer's unmodified protocol (n=6), one monkey died of cardiac failure and three developed severe anemia. In contrast, using our modified procedure (n=6), no such complication was observed in any animal. In addition, the harvested nuclear cell, mononuclear cell and CD34(+) cell counts were significantly higher with the modified method. The modified method should allow safe and efficient collection of cytokine-mobilized peripheral blood cells from non-human primates as small as human newborns in a non-invasive manner.

Leucoytapheresis with Adacolumn® enhances HCV-specific proliferative responses in patients infected with hepatitis C virus genotype 1

The most important aim in controlling virus infections is to destroy infected cells. Impaired cellular immunity in HIV and HCV infection leads to chronic infection. This study examined the effect of cytapheresis on the subsequent response to interferon/ribavirin treatment in patients infected with HCV. Adacolumn cytapheresis was carried out once a day for 5 consecutive days in patients who relapsed or did not respond to previous peginterferon and ribavirin combination treatment (n = 14: relapsers = 3, non-responders = 11). Peginterferon and ribavirin combination treatment was started after cytapheresis. During combination treatment, the proliferative response of peripheral blood mononuclear cells to HCV proteins (core, NS3, NS4, and NS5), tetanus toxoid, and phytohemagglutinin was measured, and compared to the early virological response. After treatment by leucocytapheresis, the proliferative response of peripheral blood mononuclear cells to HCV-core and tetanus toxoid increased significantly over the baseline (P < 0.05). A marked increase in the phytohemagglutinin response was observed after peginterferon and ribavirin combination treatment was started (P < 0.01 at week 5 and P < 0.005 at week 13). There were, however, no clear changes in the proliferative response to other antigens. Among the 14 patients, 12 (85.7%) achieved an early virological response by week 13 (12 weeks after the start of combination treatment). After treatment, nine patients (64.3%) had a significant proliferative response to HCV core antigen. Among the nine patients, eight patients (88.9%) achieved early virological response. The results indicate that activation of cellular immunity by leucocytapheresis facilitates an early virological response rate in HCV patients. This new therapy may, therefore, become an additional therapeutic measure for HCV.

Comparison of two mononuclear cell program settings on two apheresis devices intended to collect high yields of CD14+ and CD3+ cells

BACKGROUND

In cancer and transplantation therapy apheresis devices and software of optimum standards are required for the collection of high cell yields with high purity of the desired cell fraction.

STUDY DESIGN AND METHODS

In a paired study, 15 healthy blood donors underwent four 10-L leukapheresis procedures (197 +/- 33 min) with an inlet blood flow rate of 60 mL per minute by use of two different MNC program settings of the COBE Spectra (Gambro BCT) and the AS.TEC 204 (Fresenius Hemocare) cell separators.

RESULTS

Use of the standard MNC program of both apheresis devices resulted in significantly higher (p < 0.01) collection efficiencies of CD14+ monocytes, CD3+ cells, CD4+ cells, CD8+ T cells, CD16+ CD56+ natural killer (NK) cells, and residual PLTs (p < 0.001), owing to higher centrifuge speed. The mean MNC purity of all components was more than 90 percent. By use of standard programs of either device, significant correlations (p < 0.01) between donor monocytes and preleukapheresis NK cell counts and the corresponding component cell yields were found.

CONCLUSION

Compared to the program modifications with lower centrifuge velocities the standard MNC programs were significantly more efficient regarding CD14+, CD3+, and CD16+ CD56+ cells. Enhanced centrifuge speed and inlet blood flow rate in MNC programs resulted in higher, similar composed MNC concentrations of the products.

Granulocytapheresis is useful as an alternative therapy in patients with steroid-refractory or -dependent ulcerative colitis

BACKGROUND

Recently, granulocyte and monocyte adsorption apheresis (GCAP) has been shown to be safe and effective for active ulcerative colitis (UC). We analyzed the safety and efficacy of GCAP (G-1 Adacolumn) in patients with steroid-refractory and -dependent UC. G-1 Adacolumn is filled with cellulose acetate carriers that selectively adsorb granulocytes and monocytes/macrophages.

METHODS

Forty-four patients with UC were treated with GCAP. These patients received 5 apheresis sessions over 4 weeks. Twenty patients had steroid-refractory UC (group 1) and 10 had steroid-dependent UC (group 2). Fourteen patients who did not want readministration of steroids were treated with GCAP at the time of relapse, just after discontinuation of steroid therapy (group 3).

RESULTS

Of 44 patients treated with GCAP, 24 (55%) obtained remission (CAI < or = 4), 9 (20%) showed a clinical response, and 11 (25%) remained unchanged. Only 2 of 10 patients (20%) with severe steroid-refractory UC (CAI > or = 12) achieved remission, whereas 7 of 10 patients (70%) with moderate steroid-refractory UC achieved remission (p < 0.05). The dose of corticosteroids was tapered in 9 of 10 (90%) patients with steroid-dependent UC after GCAP therapy. Twelve (86%) of 14 patients in group 3 showed an improvement in symptoms and could avoid re-administration of steroids after GCAP. No severe adverse effects occurred.

CONCLUSIONS

The findings of this study suggest that GCAP may be a useful alternative therapy for patients with moderate steroid-refractory or -dependent UC, although cyclosporin A or colectomy is necessary in patients with severe UC. GCAP may also be useful for avoiding re-administration of steroids at the time of relapse. Randomized, controlled clinical trials are needed to confirm these findings.

Recommendations for optimized settings of the Amicus Crescendo cell separator for the collection of CD34+ progenitor cells

BACKGROUND

CD34+ PBPCs for autologous transplantation purposes are collected by leukapheresis procedures on automated cell separators. In this study, the influence of different parameters on collection efficiency (CE) of the Amicus Crescendo cell separator (Baxter) was investigated.

STUDY DESIGN AND METHODS

A total of 146 PBPC collections with Amicus cell separators were performed in 56 patients with either settings recommended by the manufacturer or modified settings to identify variables that have a significant and important impact on CE.

RESULTS

By use of a standard setting with a cycle volume of 1400 mL, CE significantly decreases when patients' preapheresis peripheral blood WBC counts are between 25,000 and 35,000 per micro L. CE can be improved if cycle volume is reduced to 1000 mL. If WBC concentrations exceed 55,000 per micro L before apheresis, CE also significantly decreases despite of reduced cycle volume. Additionally, high flow rates greater than 60 mL per minute significantly reduce CE.

CONCLUSION

Parameters influencing the outcome of CD34+ PBPC collections were identified, such as patients' WBC count, cycle volume, and whole blood flow rate. An optimized adjustment of these variables will further increase the CE of the device.

The selection of donors in multicomponent collection management

The use of cell separators in multicomponent collection (MCC) makes it possible to use donors effectively by personalising the donation on the basis of their haemotological and physical profiles and thereby standardising the product. We have applied the selection parameters currently used in our collection centre to 6687 donors using a common software programme for all: 57.6% were eligible for the various forms of MCC, although our parameters are even stricter than those required by law. Between 01 September 2001 and 28 February 2002, 345 MCC (9% of all the donations made) were performed and assessed: 111 donations of double red cell units, 153 donations of red cells and plasma, 62 donations of plasma and platelets, 19 donations of double platelet units: only slight, adverse reactions were encountered in 6% of the procedures. 68 double red cell unit donors and 65 red cell and plasma donors were then reassessed 6 months after MCC: the parameters assessed (hemoglobin, serum iron, ferritin, and total protein) were the same as the pre-donation data. All the units collected complied with legal requirements. With the use of parameters based on donor hematological and physical characteristics we can move from the concept of tailored transfusions to the concept of tailored donations thereby ensuring donor safety and meeting patient needs.

Design of novel biointerfaces (II). Fabrication of self-organized porous polymer film with highly uniform pores

Application of porous polymer materials to novel bio-interfaces for tissue engineering scaffold and artificial organs including blood filters, dialyzer, and oxygenator membranes have been in progress. The present study describes the fabrication and characterization of self-organized highly regular porous polymer films with uniform pore sizes are prepared by simple casting technique. Various fabrication parameters affecting the pore size such as polymer concentration, boiling point of solvent, cast volume and substrate are studied. The pore size can be controlled in the range from 1 to 50 microm by changing the evaporation rate of the polymer solutions. The porous film with uniform pore size is used for tissue engineering scaffold and cell separation membrane. To simulate the leukocyte eliminating from human blood, the porous film was attached to a module. The films with 5-9 microm pores provided the complete selectivity of separation for the leukocyte from the whole blood. The leukocyte elimination ratio depends on pore structures (size and depth) as well as recovery of platelet and erythrocyte.

Hematopoietic progenitor cell large volume leukapheresis (LVL) on the Fenwal Amicus blood separator

A technique for large volume leukapheresis (LVL) for hematopoietic progenitor cell (HPC) collection using the Fenwal Amicus is presented. It was compared to standard collections (STD) with regard to CD34+ cell yields and cross-cellular content. Optimal cycle volumes and machine settings were evaluated for LVL procedures. A total of 68 patients underwent 80 HPC collection procedures. Because of differences in CD34+ cell yields associated with peripheral white blood cell counts (WBC), the comparison was divided into groups of 20 with WBC < or =35 x 10(9)/L (< or =35 K) and those >35 x 10(9)/L (>35 K). Baseline CD34+ cell counts (peripheral count when patient started HPC collection) were used (median 18-23 cells/microl). Significantly more whole blood (corrected for anticoagulant) was processed with LVL (LVL 20 l vs. STD 13.5 l). For < or =35 K, median CD34+ x 10(6), WBC x 10(9), RBC ml, Plt x 10(11) yields/collection were 183, 21.2, 14, 0.8, respectively, for STD vs. 307, 22.1, 11, 1.0, respectively, for LVL. For >35 K, median CD34+ x 10(6), WBC x 10(9), RBC ml, Plt x 10(11) yields/collection were 189, 32.7, 15, 1.4, respectively, for STD vs. 69, 40.8, 21, 1.3, respectively, for LVL. We have described a method of LVL using the Amicus that, in patients with pre-procedure WBC < or =35 x 10(9)/L, collects more CD34+ cells than a standard procedure with acceptable cross-cellular content. This method is not recommended when pre-procedure WBC counts are >35 x 10(9)/L.

Efficacy and safety of femoral vascular access for peripheral blood stem cell (PBSC) collection

Central venous catheters are frequently used in leukapheresis to provide high flow rates. The most common locations are the subclavian or jugular vein, but insertion-related complications and inadequate flow are frequent problems. Experience using femoral venous access is limited, because this has been discouraged due to the high incidence of infectious or thromboembolic complications. We evaluated the safety and efficacy of 108 short-term femoral venous dialysis catheters used for the collection of peripheral blood stem cells (PBSCs). All catheters were placed by a member of the dialysis unit, and they remained in situ for the days needed to reach the target number of CD34+cells. No prophylactic antibiotic or antithrombotic therapy was used. A total of 232 apheresis sessions was performed. The longest duration a catheter remained in situ was 5 days. Most of the patients finished the collection in one or two apheresis sessions. There were no thrombotic or infectious complications, and insertion-related complications or mechanical problems were minimal. Apheresis results were similar to those reported using subclavian or jugular venous access. The short-term use of femoral venous dialysis catheters appears safe and effective for PBSC collection, simplifying the procedure, improving patient comfort, and reducing cost.