Lenograstim-mobilized peripheral blood progenitor cells in volunteer donors: an open label randomized split dose escalating study

Peripheral Blood Allogeneic Stem Cell Mobilization: Can We Predict a Suboptimal Mobilization?

Allogeneic peripheral blood stem cells mobilization is now the basis of most stem cell transplants. In a very limited number of cases, mobilization is suboptimal leading to further collection procedures, to suboptimal cell doses infusion with delayed engraftment time, increased risks of transplant procedure and of related costs. To date we have no recognized and shared criteria for early estimating the probability of poor mobilization in healthy donors. We then analyzed allogeneic peripheral blood stem cell donations performed at the Fondazione Policlinico Universitario A.Gemelli IRCCS Hospital from January 2013 to December 2021 in order to identify premobilization factors associated with successful mobilization. The following data were collected: age, gender, weight, complete blood cell count at baseline, G-CSF dose, number of collection procedures, CD34+ cell count in peripheral blood on the first day of collection, CD34+ cell dose per kg body weight of recipient. Mobilization efficacy was defined according to the number of CD34+ cells in peripheral blood on day +5 of G-CSF administration. We classified donors as sub-optimal mobilizers or good mobilizers according to the achievement of the 50 CD34+ cell/μL threshold. We observed 30 suboptimal mobilizations in 158 allogeneic peripheral blood stem cell donations. Age and baseline white blood cell count were factors significantly associated with negative or positive impact on mobilization, respectively. We did not find significant differences in mobilization based on gender or G-CSF dose. Using cut-off values of 43 years and 5.5×10⁹/L WBC count, we built a suboptimal mobilization score: donors who reach 2, 1 or 0 points have a 46%, 16% or 4% probability of suboptimal mobilization, respectively. Our model explains 26% of the variability of mobilization confirming that most of the mobilization magnitude depends on genetically determined factors; however, suboptimal mobilization score is a simple tool providing an early assessment of mobilization efficacy before G-CSF administration begins in order to support allogeneic stem cells selection, mobilization and collection. Through a systematic review, we looked for confirmation of our findings. According to the published articles, all the variables we included in our model are confirmed to be strongly related to the success of mobilization. We believe that score system approach could be applied in clinical practice to assess the risk of mobilization failure at baseline allowing for a priori intervention.

Utility of the Clinical Practice of Admnistering Thrombophilic Screening and Antithrombotic Prophylaxis with Low-Molecular-Weight Heparin to Healthy Donors Treated with G-Csf for Mobilization of Peripheral Blood Stem Cells

The aim of the study was to verify the utility of the clinical practice of administering thrombophilic screening and antithrombotic prophylaxis with low-molecular-weight heparin to healthy donors receiving granulocyte colony-stimulating factor to mobilize peripheral blood stem cells. Thrombophilia screening comprised of testing for factor V Leiden G1691A, prothrombin G20210A, the thermolabile variant (C677T) of the methylene tetrahydrofolate reductase gene, protein C, protein S, factor VIII and homocysteine plasmatic levels, antithrombin III activity, and acquired activated protein C resistance.

We investigated prospectively 72 white Italian healthy donors, 39 men and 33 women, with a median age of 42 years (range, 18-65). Five donors (6.9%) were heterozygous carriers of Factor V Leiden G1691A; two healthy donors had the heterozygous prothrombin G20210A gene mutation; C677T mutation in the methylene tetrahydrofolate reductase gene was present in 34 (47.2%) donors in heterozygous and in 7 donors (9.7%) in homozygous.

Acquired activated protein C resistance was revealed in 8 donors of the study (11.1%). The protein C plasmatic level was decreased in 3 donors (4.2%); the protein S level was decreased in 7 donors (9.7%). An elevated factor VIII dosage was shown in 10 donors (13.9%) and hyperhomocysteinemia in 9 donors (12.5%). Concentration of antithrombin III was in the normal range for all study group donors. The factor V Leiden mutation was combined with the heterozygous prothrombin G20210A in 2 cases and with protein S deficiency in one case; 2 healthy donors presented an associated deficiency of protein C and protein S. Although none of these healthy subjects had a previous history of thrombosis, low-molecular-weight heparin was administered to all donors during granulocyte colony-stimulating factor administration to prevent thrombotic events. No donor experienced short or long-term thrombotic diseases after a median follow-up of 29.2 months.

Our data do not support this clinical practice because there is no evidence that the combination of granulocyte colony-stimulating factor to previous hypercoagulable conditions results in thrombotic events.

Long-term follow-up of peripheral blood stem cell transplantation from mismatched related and unrelated donors

Allogeneic stem cell transplantation (SCT) is best performed with an HLA-identical sibling donor (matched related donor, MRD) to reduce the risk of early complications such as acute graft-vs.-host disease (aGvHD). However, as only about 30% of recipients have an MRD for this potentially curative approach, the use of family donors with one or two mismatches in the HLA-antigens (mismatch related donor, MMRD) or fully matched unrelated donors (MUD) (''alternative donors'') has been introduced in the allogeneic SCT setting in recent years. To evaluate the feasibility of allogeneic SCT from alternative donors by using peripheral blood stem cells (PBSC) we initiated a prospective, phase II study in 1996. From April 1996 to July 1998, 18 patients with various hematological malignancies underwent allogeneic SCT from alternative donors (two patients with MUD and 16 patients with MMRD). All patients received stable engraftment and none of the patients had graft rejection. The rate of aGvHD (grades II-IV) and the relapse rate at last follow-up (seven to nine yr after SCT) were with 40% and 24%, respectively, comparable with those found in patients receiving allogeneic SCT from MRD. However, five yr after allogeneic SCT only 17% were alive, which was mainly due to the treatment-related mortality (TRM) rate of 59%. We conclude that allogeneic PBSC transplantation by using alternative donors is associated with an unsatisfying long-term TRM rate. The significance of TRM and particular late deaths has to be evaluated further in this transplantation setting.

Predictive factors that affect the mobilization of CD34+cells in healthy donors treated with recombinant granulocyte colony-stimulating factor (G-CSF)

No specific characteristics have been identified as predictors of peripheral blood stem cells (PBSC) mobilization in healthy donors. In this study, clinical characteristics and laboratory data for 122 healthy donors who underwent apheresis on day 5 of treatment with recombinant granulocyte colony-stimulating factor (G-CSF) were retrospectively analyzed for correlations with CD34(+) cell mobilization. The variables that were analyzed included age, sex, body weight, basal complete blood count, and maximum white blood count (WBC) before apheresis, G-CSF type, and dosage. Median age and body weight were 42.5 years (range 16-65) and 72.5 kg (range 47-121), respectively. By univariate analysis, male sex (P = 0.007), body weight (< or = 70 vs. >70 kg, P = 0.04), and donor's age (< or = 50 vs. > 50 years; P = 0.015) were correlated with the number of CD34(+) cells mobilized. By multivariate analysis, donor's age and male sex were the only two variables that significantly predicted a high CD34(+) cell level. In conclusion, our data suggest that male sex and younger age are the only factors that significantly affect CD34(+) mobilization in healthy donors.

Rapid succession of peripheral blood progenitor cell mobilization cycles in patients with chronic heart failure: effects on the hematopoietic system

BACKGROUND

Circulating hematopoietic peripheral blood progenitor cells (PBPCs) may contribute to the regeneration of nonhematopoietic organs. An increase in circulating PBPC numbers may enhance this process. Therefore, an exploratory trial of repeated PBPC mobilization in patients with chronic heart failure was conducted. The safety and cardiovascular efficacy data have been described elsewhere. In the hematopoietic system, the trial offered an opportunity to study several new aspects of granulocyte-colony-stimulating factor (G-CSF) action.

STUDY DESIGN AND METHODS

Fourteen male patients with chronic heart failure were treated successively with G-CSF (four 10-day treatment periods interrupted by treatment-free intervals of equal length; daily dose adjustment to maintain a white blood cell [WBC] count of 45 x 10(9)-50 x 10(9)/L).

RESULTS

G-CSF induced a rapid increase in cells of all WBC lineages with return to levels equal to (neutrophilic, eosinophilic, and basophilic granulocytes) or lower than those before treatment (monocytes, lymphocytes) during the treatment-free intervals. Red cell counts remained unchanged, but platelet counts decreased followed by rebound thrombocytosis. The extent of CD34+ cell mobilization was highly variable. For each patient, the changes induced were identical through all cycles, but the G-CSF dose required in the first cycle was significantly higher than in subsequent cycles. In the cohort of patients, an inverse correlation was observed between the WBC level reached and the dose of G-CSF administered.

CONCLUSIONS

Rapid alternation between PBPC mobilization and recovery periods is feasible, with identical alterations in all treatment cycles. G-CSF responsiveness varies among patients and is increased by pretreatment with G-CSF.

Factors affecting PBSC mobilization and collection in healthy donors

Peripheral blood stem cells are widely used as stem cell source for allografting. Progenitor cells can be effectively mobilized into peripheral blood in majority of healthy donors with a brief administration of G-CSF. A mobilization course in 111 donors (median age 40years) was retrospectively studied and the factors influencing the efficacy of mobilization were analyzed. The median number of CD34+ cells per kg recipient weight 5.1x10(6) was obtained after a median of two aphereses. The target cell dose (4.0x10(6)/kg) was reached in 69% of donors. Circulating CD34+ count and CD34+ yield were negatively associated with donor's age. Other independent factors associated with superior yield were precollection platelet and WBC counts. In multivariate analysis only CD34+ precount predicted for CD34+ yield. G-CSF had an acceptable short-term safety profile. Our data confirm that apheresis is a safe procedure in healthy including aged donors and suggest that older donors could be poorer mobilizers than younger.

Superior mobilisation of haematopoietic progenitor cells with glycosylated G-CSF in male but not female unrelated stem cell donors

Granulocyte colony-stimulating factor (G-CSF) effectively mobilises haematopoietic stem cells to the peripheral blood. It is unclear whether the mobilisation of stem cells with lenograstim (glycosylated G-CSF) or filgrastim (non-glycosylated G-CSF) leads to a higher cell number of collected engraft able progenitor cells. Thus, we investigated harvesting efficiency of the licensed G-CSF preparations in mobilising peripheral stem cells in a randomised study. A total of 501 healthy unrelated donors, including 339 males and 162 females received either lenograstim (n = 261) or filgrastim (n = 240) at 10 microg/kg body weight (BW) per day. Aphaeresis was performed on day 5 and, if necessary, on day 6 of mobilisation. The number of CD34+ cells collected was 11.5% higher in the lenograstim group (7.19 x 10(6) vs. 6.44 x 10(6)/kg BW donor; P < 0.03). Univariate variance analysis revealed that this effect was caused by male donors: more progenitors cells per kg BW of the donor (7.73 x 10(6) vs. 6.88 x 10(6); P < 0.017) and of the recipient (10.1 x 10(6) vs. 8.88 x 10(6), P < 0.029) could be harvested. There was no significant difference in the percentage of donors in whom a second aphaeresis was required (9.6% vs. 11.6%). Lenograstim mobilises progenitor cells into the peripheral blood more effectively in males than filgrastim.

Efficacy of the interleukin-2 receptor antagonist basiliximab in steroid-refractory acute graft-versus-host disease

Acute graft-versus-host disease (aGVHD) occurs in up to 80% of patients who undergo allogeneic stem cell transplantation (SCT) and contributes significantly to transplant-related mortality (TRM). We conducted a prospective phase II trial to assess the efficacy and feasibility of treating steroid-refractory aGVHD with basiliximab, a chimaeric monoclonal antibody directed against the alpha chain of the interleukin-2 (IL-2) receptor. Basiliximab was administered intravenously at a dose of 20 mg on days 1 and 4. Twenty-three patients were enrolled between October 1999 and July 2004. We found a primary overall response rate of 82.5% with four patients (17.5%) showing a complete response and 15 patients (65%) a partial response. Six patients were again treated successfully with an IL-2 receptor antagonist because of recurrence of aGVHD. The rates of infections, chronic GVHD, malignancy recurrence and 1-year TRM following immunosuppression with basiliximab were comparable with those found with other treatment modalities for aGVHD. We conclude that basiliximab is efficient and feasible for steroid-refractory aGVHD and merits further evaluation.

Harvesting peripheral blood progenitor cells from healthy donors with a short course of recombinant human granulocyte-colony-stimulating factor

A short-course administration of non-glycosylated granulocyte-colony-stimulating factor (G-CSF) was investigated in 68 healthy donors (HDs) in order to collect > or = 4 x 10(6) CD34+ cells per kilogram of recipient's body weight. G-CSF was given at 10 microg/kg per day administered in two divided doses for 3 days. Leukapheresis was scheduled on day 4, 12 h after the last dose of G-CSF. A median of 35.6 circulating CD34+ cells microL(-1) (range, 3.1-185) was found on the day of leukapheresis. This allowed a median collection of CD34+ cells of 4.2 x 10(6) per kilogram of recipient's weight (range, 1.0-17.4). One single procedure was sufficient to reach the target level of CD34+ cells in 36 (53%) of 68 donors; significant correlations were found between the number of CD34+ cells collected on day 4 and the patient's sex, body-weight and volume of blood processed. A retrospective analysis was made with a historical group of HDs collected on day 5. The day 5 schedule allowed a more consistent achievement of the target cell dose with one leukapheresis (P = 0.005) and resulted in the initial collection of a significantly larger number of CD34+ cells (P = 0.006).

Stem cell mobilization by G-CSF in solid and hematological malignancies: Single daily dose is better than split dose in obese patients

In the past, variable results were reported for single daily and two divided daily doses of granulocyte colony-stimulating factor (G-CSF) in stem cell collection where no study exists investigating the effect of body mass index (BMI) on mobilization. The numbers of CD34(+) cells collected were compared in 86 patients with solid or hematological malignancies receiving either single daily (14 mug/kg/day) G-CSF (filgrastim) as group I (n=36) or two divided doses of G-CSF daily (2 x 7 mug/kg/day) as group II (n = 50). Both groups were divided into subgroups according to their BMI as group a (BMI </=25 kg/m(2)) and group b (BMI >25 kg/m(2)). Two groups were similar in terms of BMI, gender, and disease characteristics. All patients have received G-CSF as a single or two divided doses subcutaneously and aphereses have been done on the 5th day. No significant difference in numbers of CD34(+) cells between groups Ia and Ib, groups IIa and IIb, and groups Ia and IIa was found. On the other hand, the mean ratio and the number of CD34(+) cells in group Ib were significantly higher than those of group IIb (0.58 +/- 0.06% vs. 0.37 +/- 0.26%, P = 0.01 and 3.67 +/- 0.65 x 10(4)/kg/ml vs. 1.92 +/- 0.37 x 10(4)/kg/ml, P= 0.02). In conclusion, in patients with BMI >25 kg/m(2), once daily G-CSF compared to split dose administration induces a greater number of CD34(+) stem cell mobilization, which suggests the presence of a different pharmacokinetics in obese patients.

Reduced intensity preparative regimens for allogeneic hematopoietic stem cell transplantation: a single center experience

According to recent reports, fast engraftment with minimal transplant-related toxicity and mortality (TRT, TRM) can be achieved by using reduced-intensity preparative regimens in allogeneic hematopoietic stem cell transplantation (HSCT). We report our experience with related (39%) and unrelated (61%) HSCT in 44 high risk patients (AML, ALL, CML, CLL) receiving either busulfan/fludarabine or busulfane/fludarabine/ATG or TBI/fludarabine as reduced-intensity preparative regimens. Organ toxicity was minimal with mild mucositis and no major bleeding. Acute GVHD was recorded in 64% of the patients. Twenty-three patients achieved complete remission after transplantation, and complete chimerism was obtained in all patients with stable engraftment (35 patients). Twenty-nine patients died: 15 due to relapse/progression, 14 due to TRM. Survival with median follow-up of 18.5 months was significantly better in patients with matched related transplants compared to patients with other transplants. However, there was no difference between related and unrelated transplants with regard to engraftment, TRM and GVHD. In conclusion, our results in high-risk patients transplanted in CR or with smoldering leukemia from a related donor are encouraging, although a longer follow-up and a larger group of patients is needed in order to evaluate the role of different reduced-intensity preparative regimens in unrelated and related HSCT.

Allogeneic peripheral blood stem cell transplantation

Granulocyte colony stimulating factor (G-CSF)-mobilized peripheral blood stem cells (PBSC) are now widely used instead of bone marrow for autologous transplantation due to earlier hematopoietic recovery after transplant. The low toxicity of G-CSF has prompted phase I and II studies to evaluate PBSC for allogeneic transplantation; these studies have demonstrated that engraftment of neutrophils, red blood cells and platelets is faster with peripheral blood cells compared to marrow. In randomized studies comparing mobilized PBSC and marrow for allogeneic transplantation, most trials have confirmed significantly earlier engraftment with PBSC and similar risks of acute graft-vs.-host disease (GVHD). In some trials, an increase of 10-15% in grade II-IV GVHD has been noted with PBSC. All studies showed a trend towards more chronic GVHD with PBSC. Some randomized studies have shown improved survival and disease-free survival with the use of PBSC due to lowered transplant-related mortality and fewer relapses in recipients of PBSC as a result of improved immune reconstitution and a graft-vs.-leukemia (GVL) effect. This survival benefit is most apparent in patients with more advanced hematologic malignancies, but further studies are needed to define the relative benefits of PBSC for patients with less advanced disease. The GVL effect of PBSC is currently being exploited with the use of non-ablative allografts.

Safety of granulocyte colony-stimulating factor in normal donors

Granulocyte colony-stimulating factor (G-CSF), which is widely used to mobilize peripheral blood stem cells (PBSC) from normal donors, has led to the use of PBSC as a major alternative to bone marrow for patients undergoing allogeneic transplants. Safety issues related to the administration of G-CSF to normal donors, however, are still under study. The short-term effects after G-CSF administration are well known and manageable. G-CSF induces a hypercoagulable state, which may predispose certain donors to thrombotic complications. A dose of 10 microg/kg/d for 5 days has been recommended for routine clinical use, but the optimal dose and schedule for PBSC collection are still being defined. Small studies to date have shown no late effects of G-CSF administration but there is insufficient information regarding any long-term adverse effects or risks. Although the administration of G-CSF to normal donors for PBSC collection appears safe, longer follow-up is required.