Hematopoietic progenitor cells (HPC) and immature reticulocytes evaluations in mobilization process: new parameters measured by conventional blood cell counter

An alternative test for determining autologous stem cell transplantation cell harvesting outcome: Comparison between predictive values of two tests

Daily CD34+ cells enumeration as a success indicator of stem cell pheresis procedure using flow cytometry is costly, lengthy, and labor-intensive. Thus, finding a simpler method to achieve the optimum time for harvesting the minimum required stem cells for transplantation could be helpful. The aim of this study was to evaluate the predictive value of reticulocytes fractions and their sensesivity and specificity in guiding CD34+ cell harvesting by G-CSF mobilization strategy. In this study, 49 candidates for autologous peripheral blood stem cell transplantation were enrolled. Before leukapheresis, the immature reticulocytes fraction (IRF) and CD34+ cell count were measured. Moreover, patients were evaluated for leukapheresis outcomes in two MNC and cMNC groups. Here we demonstrated that IRF, LFR, and MFR with the associated criterion of >17.3, ≤82.5, and >15.9, respectively, earned 100 % specificity and 47.2 %, 47.22 %, and 41.46 % sensitivity to predict the minimum required CD34+ cell count. Furthermore, IRF-V (Value) and MFR-V with the associated criterion of >0.77 and >0.55, respectively, earned 58.33 %, 66.67 % sensitivity and 84.62 %, 69.23 % of specificity, separately. As only MFR-V was able to predict the platelet engraftment (P-value = 0.014), none of the other above mentioned factors were not able to predict the neutrophil engraftment. Likewise, it was shown that patients who underwent MNC leukapheresis had a statistically significantly higher total WBC, harvested CD34⁺ cells, MNCs/ kg, and lower apheresis durations (P-values<0.05). Taken together, using IRF and its maturity stages seems to be a compelling predictor of minimal required CD34+ cells in autologous peripheral blood stem cell transplantation.

Factors determining pbsc mobilization efficiency and nonmobilization following ICE with or without rituximab (R-ICE) salvage therapy for refractory or relapsed lymphoma prior to autologous transplantation

ICE/R-ICE (ifosfamide, carboplatin, and etoposide without or with rituximab) chemotherapy followed by autologous stem cell transplantation is an established regimen in refractory/relapsed lymphoma. Few studies have addressed which factors are important in determining peripheral blood stem cell (PBSC) mobilization efficiency or nonmobilization following ICE/R-ICE. Between 2004 and 2013, 88 patients with refractory/relapsed lymphoma who received ICE/R-ICE salvage-chemotherapy prior to granulocyte colony stimulating factor (G-CSF) stimulated PBSC mobilization at a single center were identified. Mobilization efficiency was assessed by time from ICE/R-ICE to day of harvest, duration of G-CSF use, days to peripheral blood (PB) CD34(+) ≥15/µL, PB CD34(+) number on harvest day, CD34(+) yield and nonmobilization rate. Median PB CD34(+) at harvest were 54/μL (7-524); median days to first apheresis was 15 (11-30); median harvested total CD34(+) were 5.46 × 10(6) /kg (0.96-44.36); 71 patients (80.7%) successfully mobilized; 20 (22.7%) patients were poor mobilizers; 14 (15.9%) patients were considered nonmobilizers with maximal PB CD34(+) <7/µL and did not proceed to apheresis. Six of 20 poor mobilizers were apheresed with PB CD34(+) 7-12/µL, 50% were successfully harvested. No differences were found between ICE and R-ICE regimens. Impaired mobilization efficiency was associated with age, remission status, >1 line of induction chemotherapy, four cycles ICE/R-ICE and grade 4 neutropenia. Prior bone marrow (BM) involvement was associated with nonmobilization. The majority of patients can be successfully mobilized with ICE/R-ICE. Prior BM involvement is associated with high rates of nonmobilization following ICE/R-ICE. Such patients may benefit from novel mobilization agents and/or alternative salvage regimens to ICE/R-ICE.

Mobilization and collection of peripheral blood stem cells: guidelines for blood volume to process, based on CD34-positive blood cell count in adults and children

We report 189 mobilizations and 489 collections of peripheral blood stem cells (PBSC) performed in 139 autologous transplantation patients and in 28 donors for allogeneic transplantations whose ages ranged from 2-68 years. We observed a correlation (P < .001; Pearson's coefficient 0.64) between CD34-positive cells and granulocyte-macrophage colony-forming units examined to estimate PBSC. In a subset of 287 collections (97 adults and 49 children) we obtained peripheral blood (PB) CD34-positive cell counts at 2 to 4 hours before leukapheresis. We noted a correlation between PB CD34-positive cell counts before leukapheresis and the number of CD34-positive cells per kilogram of body weight collected in the whole apheresis of the day (P < .001; Pearson's coefficient 0.82). An even better correlation was obtained between PB CD34-positive cells preapheresis and the yield of each individual blood volume (BV) processed (P < .001; Pearson's coefficient 0.87). Healthy donors and patients in each age group behaved similarly. In addition, the collection yield was greater among children than adults. These findings allowed us to develop a simple predictive model to estimate the BV to process for a target dose of CD34-positive cells per kilogram, based on the level of PBSC before apheresis in children and adults.