外周血CD34+细胞绝对计数可靠预示自体外周血干细胞采集效果

目的　为确定外周血CD34+细胞绝对计数能否可靠预示自体外周血干细胞的采集效果。方法　用流式细胞仪ProCOUNT方法对采集的 2 5份次移植物和采集当天外周血行CD34+细胞绝对计数 ,同时做外周血常规检查和移植物集落形成单位 (CFU)计数 ,每份次移植物以CD34+/kg ,单个核细胞 (MNC) /kg,粒 巨噬细胞集落形成单位 (CFU GM) /kg ,红细胞集落形成单位 (CFU E) /kg等为指标 ,与患者采集当天的外周血CD34+细胞绝对计数、CD34+细胞百分比、WBC ,MNC ,中性粒细胞(NEU)或血小板 (PLT)等各项指标进行相关分析和逐步回归分析。结果　 ( 1)Spearman相关分析结果 :外周血CD34+细胞绝对计数与移植物CD34+/kg高度相关 (r=0 790 ,P <0 0 0 1) ,外周血CD34+细胞百分比与移植物CD34+/kg相关 (r=0 6 17,P <0 0 5 )。外周血WBC、MNC、NEU、PLT或RBC与移植物CD34+/kg无关。外周血CD34+细胞绝对计数与移植物CFU E相关 ,而与CFU GM无关。外周血MNC与移植物MNC/kg相关。 ( 2 )逐步回归分析结果 :移植物CD34+/kg只与外周血CD34+细胞绝对计数高度相关 (P <0 0 0 1) ,而与外周血CD34+细胞百分比无关。结论　移植物CD34+/kg只与外周血CD34+细胞绝对计数高度相关 ,外周血CD34+细胞绝对计数能够可靠预示自体外周血干细胞的采集效果     

The predictive value of white cell or CD34+ cell count in the peripheral blood for timing apheresis and maximizing yield

BACKGROUND: The collection of peripheral blood stem and progenitor cells (PBPCs) for transplantation can be time-consuming and expensive. Thus, the utility of counting CD34+ cells and white cells (WBCs) in the peripheral blood was evaluated as a predictor of CD34+ cell yield in the apheresis component. STUDY DESIGN AND METHODS: The WBC and CD34+ cell counts in the peripheral blood and the apheresis components from 216 collections were assessed. Sixty-three patients underwent mobilization with chemotherapy plus filgrastim, and 17 patients and 14 allogeneic PBPC donors did so with filgrastim alone. The relationship between the number of WBC and CD34+ cells in the peripheral blood and in the apheresis component was analyzed by using rank correlation and linear regression analysis. RESULTS: The correlation coefficient for CD34+ cells per liter of peripheral blood with CD34+ cell yield (x 10(6)/kg) was 0.87 (n = 216 collections). This correlation existed for many patient and collection variables. However, patients with acute myeloid leukemia had fewer CD34+ cells in the apheresis component at any level of peripheral blood CD34+ cell count. Components collected from patients with CD34+ cell counts below 10 x 10(6) per L in the peripheral blood contained a median of 0.75 x 10(6) CD34+ cells per kg. When the WBC count in the blood was below 5.0 x 10(9) per L, the median number of CD34+ cells in the peripheral blood was 5.6 x 10(6) per L (range, 1.0-15.5 x 10(6)/L). A very poor correlation was found between the WBC count in the blood and the CD34+ cell yield (p = 0.12, n = 158 collections). CONCLUSION: The number of CD34+ cells, but not WBCs, in the peripheral blood can be used as a predictor for timing of apheresis and estimating PBPC yield. This is a robust relationship not affected by a variety of patient and collection factors except the diagnosis of acute myeloid leukemia. Patients who undergo mobilization with chemotherapy and filgrastim also should undergo monitoring of peripheral blood CD34+ cell counts, beginning when the WBC count in the blood exceeds 1.0 to 5.0 x 10(9) per L.     

Preapheresis peripheral blood CD34+ mononuclear cell counts as predictors of progenitor cell yield

BACKGROUND: Peripheral blood progenitor cells, harvested by apheresis after mobilization, provide rapid hematologic recovery after high-dose chemotherapy. However, because harvesting these cells is expensive and time-consuming, there has been much interest in optimizing collection protocols. An investigation was made to determine whether, in this clinical setting, peripheral blood progenitor cell yields may be predicted from preapheresis progenitor cell counts, allowing the length of each procedure to be "fine tuned" to achieve specific target goals. STUDY DESIGN AND METHODS: Preapheresis peripheral blood CD34+ cell and total colony-forming cell counts were assessed before 78 peripheral blood progenitor cell collections from 13 consecutive patients were performed. Preapheresis counts were correlated with actual progenitor cell yields. Factors affecting this correlation were analyzed. RESULTS: With the use of linear regression analysis preapheresis progenitor cell counts were found to correlate significantly but weakly with actual yields per kg of body weight per liter of blood processed (CD34+ cells: r = 0.43; colony-forming cells: r = 0.56). Further analysis revealed two possible causes: 1) circulating progenitor cell concentrations fluctuate widely during harvest, which implies that preapheresis counts are not representative of actual concentrations during apheresis, and 2) the efficiency with which apheresis machines extract mononuclear cells varies greatly between procedures. CONCLUSION: Preapheresis CD34+ and colony-forming cell counts correlated poorly with subsequent yields in this clinical setting, which suggests that it is not practical to use such counts to predict with certainty the length of apheresis needed to achieve a target yield.     

Evaluation of an algorithm based on peripheral blood hematopoietic progenitor cell and CD34+ cell concentrations to optimize peripheral blood progenitor cell collection by apheresis

BACKGROUND: Quantification of peripheral blood (PB) CD34+ cells is commonly used to plan peripheral blood progenitor cell (PBPC) collection but is time-consuming. Sysmex has developed a hematology analyzer that can quickly identify a population of immature hematopoietic cells (HPCs) according to cell size, cell density, and differential lysis resistance, which may indicate the presence of PBPCs in PB. This prospective study has evaluated the potential of such method to predict the PBPC mobilization. STUDY DESIGN AND METHODS: A total of 141 patients underwent PBPC mobilization. PB HPCs and PB CD34+ cells were simultaneously quantified with a hematology analyzer (SE2100, Sysmex) and flow cytometry, respectively. The number of blood volumes processed was then based on PB CD34+ cell concentration. RESULTS: The optimal PB HPC level able to predict a minimal level of 10 x 10(6) PB CD34+ cells per L was 5 x 10(6) per L with positive and negative predictive values of 0.93 and 0.36 percent, respectively. For this cutoff point, sensitivity and specificity were 0.81 and 0.65, respectively. The median number of blood volumes processed according to the PB CD34+ cell count allowed us to perform only one apheresis procedure for a majority of patients. CONCLUSION: PB HPC quantification is very useful to quickly determine the initiation of PBPC apheresis especially for patients with higher concentrations. For patients exhibiting a lower HPC count (<5 x 10(6)/L), other parameters such as a CD34 test may be needed. Such a policy associated with a length of apheresis adapted to the richness in the PB CD34+ cells allows for optimizing the organization of centers with an improvement in patient comfort and economical savings.     

The absolute number of circulating CD34+ cells as the best predictor of peripheral hematopoietic stem cell yield.

Many controversies still exist about the timing of leukapheresis procedures for PBSC transplantation. Thirty-nine patients were followed daily by monitoring the absolute PB WBC count and CD34+ cell enumeration prior to apheresis. These determinations were compared with the apheresis cell content (nucleated cells and CD34+ cells yield). There was a highly significant correlation between PB CD34+ cells and apheresis CD34+ cell yield (r = 0.921, p < 0.001). A small but significant correlation was found between the PB WBC count and the apheresis nucleated cell content (r = 0.383, p < 0.001), but no correlation was found between PB WBC count and apheresis CD34+ cell yield (r = -0.065, p = 0.460). A target value of 20 x 10(6) CD34+ cells/L was determined to be the most reliable predictor to collect at least 1.0 x 10(6) CD34+ cells/kg in a single apheresis. Of the 39 patients, 20 could be followed after transplantation, and a good correlation was found for total number of CD34+ cells reinfused and platelet and neutrophil engraftment. No correlation was found for nucleated cells infused and engraftment. CD34+ cell determination is a better predictor than WBC count for timing leukapheresis and is thus recommended for monitoring the quality of the product.     

Evaluation of a new cell separator for collection of peripheral blood CD34+ progenitor cells in pediatric patients

BACKGROUND: This study was conducted to evaluate the performance of the COM.TEC cell separator (Fresenius HemoCare GmbH) for collecting CD34+ cells in pediatric patients who were intended to have autologous peripheral blood progenitor cell transplantation, with respect to collection variables, prediction power of CD34+ cell yield, and influence on donors. STUDY DESIGN AND METHODS: A total of 26 pediatric solid tumor patients who received mobilization chemotherapy and granulocyte–colony‐stimulating factor underwent CD34+ cell collection (n = 96) using the COM.TEC auto mononuclear cell (MNC) program. Patients were divided into a neuroblastoma (NBL) group and a brain tumor group according to the intensity of prior chemotherapy regimens. The collection variables, cellular variables of leukapheresis products, and the peripheral blood cell counts of patients were compared with those acquired using the COBE Spectra (GambroBCT). The CD34+ cell collection efficiency (CE) and the percentage ratios of actual to predicted CD34+ cell yield indicating prediction power were analyzed. RESULTS: Using the COM.TEC auto MNC program, the processing rate was higher and the product volume was smaller (p < 0.05) than those of the COBE Spectra. Platelet (PLT) reduction in peripheral blood and PLT contamination of the products were significantly lower (p < 0.01). The median CE was less than 60% in both patient groups (50.0 and 48.4%, respectively). The actual collected CD34+ cell yields were medians of 66.9 and 76.1% of the predicted values in NBL group and brain tumor group, respectively. CONCLUSION: PBPC collections by the COM.TEC cell separator had advantages of high processing rate, low product volume, and low contamination by PLTs of product. Low PLT loss was observed in pediatric patients who need to collect autologous PBPCs. However, applying CD34+ cell yield prediction was not practical for prospective scheduling of the next collection. More specified data need to be accumulated for more accurate prediction of CD34+ cell yield in pediatric patients.     

Semi-automated flow cytometric analysis of CD34-expressing hematopoietic cells in peripheral blood progenitor cell apheresis products

BACKGROUND: The measurement of CD34+ cells is the most important step in the quality control of peripheral blood progenitor cell apheresis products. For this purpose, flow cytometry is applied. Recently, a new test kit has been introduced for the enumeration of CD34-expressing cells, in combination with software support for semi-automation of data acquisition and analysis. STUDY DESIGN AND METHODS: This study evaluated the ProCOUNT kit. Ninety samples obtained from peripheral blood progenitor cell apheresis products from 39 patients with hemato-oncologic diseases were analyzed. For data acquisition and analysis, ProCOUNT software was used. Data comparison was performed with parallel measurements according to the International Society for Hematotherapy and Graft Engineering (ISHAGE) guidelines and the German reference protocol for analysis of CD34-expressing cells. RESULTS: Correlation of the German and ISHAGE techniques was excellent (r2 = 0.99). The initial correlation coefficient of ProCOUNT analysis with the German protocol was r2 = 0.89. In 21 (23.3%) of 90 ProCOUNT analyses, a warning message was encountered from the ProCOUNT software. Following manual reevaluation of these data with CellQUEST software, a correlation of r2 = 0.96 with the German protocol and r2 = 0.97 with the ISHAGE analyses was obtained. ANOVA testing revealed significant differences between ProCOUNT and ISHAGE techniques (p<0.05) and between ProCOUNT and the German protocol (p<0.05). No statistically significant difference between ISHAGE and German protocol was observed (p = 0.19). CONCLUSION: The ProCOUNT kit and software for semi-automated data acquisition and analysis represents a further step toward standardization of CD34 cell quantitation in peripheral blood progenitor cell apheresis products. However, the occurrence of software warnings is high, and analysis or data reevaluation by experienced staff is still mandatory. Therefore, currently there is no definite advantage of the kit and software over the existing guidelines for CD34+ analysis in peripheral blood progenitor cell grafts.     

Monitoring of peripheral blood CD34+ cell counts on the first day of apheresis is highly predictive for efficient CD34+ cell yield.

The purpose of this study was to evaluate the correlation of preleukapheresis circulating CD 34+ cells/micro L, white blood cells (WBC), and platelet counts on the first day of apheresis with the yield of collected CD 34+ cell counts in 40 patients with hematological malignancies (n = 29) and solid tumors (n = 11). The median numbers of apheresis cycles, numbers of CD 34+ cells, peripheral blood (PB) mononuclear cells, and total nucleated cells collected were 2 (range, 1-4), 5.5 x 106/kg (range, 0.05-33.78), 2.59 x 108/kg (range, 0.04-20.68), and 7.36 x 108/kg (range, 0.15-28.08), respectively. There was a strong correlation between the number of preleukapheresis circulating CD 34+ cells/micro L and the yield of collected CD 34+ cells per kilogram (r = 0.962, p < 0.001). The threshold levels of PB C 34+ cell/micro L to obtain > or =1 x 106/kg and > or =2.5 x 106/kg CD 34+ cell in one collection were 12/micro L and 34/ micro L, respectively. Fifteen of 17 (88%) patients who had > or =34 CD 34+ cells/ micro L in the PB before collection reached the level of > or =2.5 x 106/kg in a single apheresis. Despite a low r value, WBC and platelet counts on the first day of apheresis also correlated with the yield of collected daily CD 34+ cells per kilogram (r = 0.482, p < 0.01 and r = 0.496 p < 0.01, respectively). These data suggest that preleukapheresis circulating CD 34+ cells/ micro L correlated significantly better with the yield of collected CD 34+ cells than WBC and platelet counts on the first day of apheresis. Using a value of 34/micro L preleukapheresis circulating CD 34+ cells as a guide for the timing of peripheral blood stem cells collections can be time saving and cost-effective.     

The number of CD34(+) cells in peripheral blood as a predictor of the CD34(+) yield in patients going to autologous stem cell transplantation

The number of CD34(+) cells in peripheral blood (PB) is a guide to the optimal timing to harvest peripheral blood progenitor cells (PBPC). The objective was to determine the number of CD34(+) cells in PB that allows achieving a final apheresis product containing > or =1.5 x 10(6) CD34(+) cells/kg, performing up to three aphereses. Between March 1999 and August 2003, patients with hematological and solid malignancies who underwent leukapheresis for autologous bone marrow transplantation were prospectively evaluated. Seventy-two aphereses in 48 patients were performed (mean 1.45 per patient; range 1-3). PBPC were mobilized with cyclophosphamide plus recombinant human granulocyte-colony stimulating factor (G-CSF) (n = 40), other chemotherapy drugs plus G-CSF (n = 7), or G-CSF alone (n = 1). We found a strong correlation between the CD34(+) cells count in peripheral blood and the CD34(+) cells yielded (r = 0.903; P < 0.0001). Using receiver-operating characteristic (ROC) curves, the minimum number of CD34(+) cells in PB to obtain > or =1.5 x 10(6)/kg in the first apheresis was 16.48 cells/microL (sensitivity 100%; specificity 95%). The best cut-off point necessary to obtain the same target in the final harvest was 15.48 cells/microL, performing up to three aphereses (sensitivity 89%; specificity 100%). In our experience, > or =15 CD34(+) cells/microL is the best predictor to begin the apheresis procedure. Based on this threshold level, it is possible to achieve at least 1.5 x 10(6)/kg CD34(+) cells in the graft with < or =3 collections.     

Minimal number of circulating CD34+ cells to ensure successful leukapheresis and engraftment in autologous peripheral blood progenitor cell transplantation

BACKGROUND: The number of peripheral blood (PB) CD34+ cells has been widely used to monitor the timing of leukapheresis for autologous transplantation. However, no cutoff value for CD34+ cells in PB has been defined as a guideline for the identification of patients in whom the harvest would be effective and those in whom there was a high probability of failure. STUDY DESIGN AND METHODS: The present study investigated the best threshold of CD34+ cells in PB for successful harvesting and engraftment, using 263 PB samples with their corresponding leukapheresis components. In addition, that measure has been compared to other commonly used criteria such as the white cell count, the number of mononuclear cells, and the number of colony- forming units-granulocyte macrophage in PB. RESULTS : Time to engraftment of both granulocytes and platelets was significantly influenced by the number of CD34+ cells transfused, but all patients receiving > or = 0.75 × 10(6) CD34+ cells per kg achieved engraftment within a reasonable number of days (> 0.5 × 10(9)/L granulocytes by Day 11 and > 20 × 10(9)/L platelets by Day 13). A clear correlation between the number of CD34+ cells per microL in PB and of CD34+ cells per kg collected was found at each apheresis (r = 0.9, p < 0.0001). Moreover, the number of CD34+ cells per microL measured in PB the day the first leukapheresis was initiated displayed an excellent correlation with the total amount of CD34+ cells per kg finally collected (r = 0.81, p < 0.0001). On the basis of the regression curve obtained and the clinical engraftment results, it was found that the presence of > 5 CD34+ cells per microL in PB ensured a good yield from the harvest in 95 percent of patients and would avoid an unsuccessful harvest in 81 percent of cases. CONCLUSION: A dose of only 0.75 × 10(6) CD34+ cells per kg guarantees hematopoietic recovery within a reasonable number of days. To initiate a leukapheresis from which enough progenitor cells may confidently be obtained, a minimum of 5 CD34+ cells per microL in PB is required.     

Tempo of hematologic recovery correlates with peripheral blood CD34+ cell level in patients undergoing stem cell mobilization

This study was undertaken to evaluate the relationship between the time to recovery of peripheral blood counts and CD34+ cells in the peripheral blood (PB) and apheresis collections of patients undergoing intensive chemotherapy followed by rhG-CSF. Twenty-three patients with a median age of 42 years (range 17–64) with malignancies underwent peripheral blood stem cell (PBSC) collection after cyclophosphamide (CY) 4 g/m² and etoposide (600 mg/m²) followed by rhG-CSF (10 μg/kg/day). The WBC, platelet counts, CD34+ cell counts per ml of PB, and CD34+ cells in apheresis products were followed in all patients. The relationship of the time to recovery of WBC >1,000/μl, >3,000/μl, >10,000/μl and platelets >20,000/μl and 50,000/μl was compared to the average daily CD34+ cells/ml in each patient using the Spearman Correlation test. The tempo of recovery of WBC and platelets were highly correlated with the average CD34+ cell count in blood. In order to derive some useful guidelines for the timing of apheresis, the patients were divided into two groups, early recover (ER) and late recover (LR) based on the median time (day 10) to reach WBC count greater than 1,000/μl. ER patients had an average daily PB CD34+ cell count of 9.04 × 10⁴/ml (range 0.44–17.5) and a median yield of CD34+ cells of 10.43 × 10⁶/kg (range 0.60–25.95) compared to LR patients, who had 1.87 × 10⁴/ml (range 0.32–5.44) in the PB (P = .001) and a yield 3.20 × 10⁶/kg CD34+ cells (range 0.037–9.39) (P = .001). Patients recovering their WBC to 1,000/ml within 10 days of completing this regimen may undergo PBSC collection and achieve minimum-target cell doses of >2.5 × 10⁶ CD34+ cells/kg—100% of the time. J. Clin. Apheresis 13:1–6, 1998. © 1998 Wiley-Liss, Inc.     

CD133+CD34+ and CD133+CD38+ blood progenitor cells as predictors of platelet engraftment in patients undergoing autologous peripheral blood stem cell transplantation

BackgroundHematopoietic stem cells (HSC) have been characterized by CD34+ expression and an adequate dose of CD34+ cells is associated with a complete engraftment. CD133 is a more specific marker of HSC.Materials and methodsWe studied the relationship between graft content of CD34+, CD133+, and CD38+ cells and trilineage engraftment after autologous stem cell transplantation in patients with different hematological disorders. Blood samples were obtained before and after mobilization with recombinant granulocyte-colony stimulating factor (G-CSF, 16 μg/kg), from apheresis collections, and after transplantation.ResultsCell subsets were quantified by flow cytometry, and the dose of each population infused was correlated with success of engraftment. G-CSF induced mobilization of CD133+CD38+ cells (12.6-fold) and CD133+CD34+ cells (14.7-fold). A correlation was observed between the infused dose of CD133+CD34+ and CD133+CD38+ cells and platelet engraftment.ConclusionCD133+CD34+ and CD133+CD38+ cells were mobilized with G-CSF and these cell subsets were correlated with platelet engraftment.     

Comparison of intermittent- and continuous-flow cell separators for the collection of autologous peripheral blood progenitor cells in patients with hematologic malignancies

BACKGROUND: The transplantation of autologous peripheral blood progenitor cells (PBPCs) after high-dose chemotherapy is a valuable therapy for patients with hematologic and solid malignancies. Several methods are used for harvesting PBPCs. The efficiency of intermittent- and continuous-flow blood cell separators in collecting progenitor cells from the blood of patients undergoing myeloablative treatment for cancer was compared. STUDY DESIGN AND METHODS: PBPC components (n = 133) were obtained from 72 patients by leukapheresis with continuous-flow machines (Spectra, COBE; CS 3000 Plus, Baxter) and with an intermittent-flow machine (MCS 3P, Haemonetics). The data were analyzed retrospectively. Blood samples obtained from the patients before leukapheresis and samples of the leukapheresis components themselves were analyzed for their content of RBCs, WBCs, platelets, and CD34+ cells. RESULTS: The Spectra processed more than twice the blood volume in the shortest time (15 L in 178 min), whereas the Baxter CS 3000 Plus (10 L in 185 min) and the MCS 3P (4.8 L in 239 min) processed significantly smaller volumes in a longer time. The mean ACD consumption was 403 mL with the MCS 3P, 900 mL with the CS 3000 Plus, and 1000 mL with the Spectra. The product volumes were 50 mL (CS 3000 Plus), 69 mL (MCS 3P), and 166 mL (Spectra). In all groups, differences in the preapheresis hemograms were not significant, but the Spectra group had fewer CD34+ cells than the other groups. Despite this, the differences in the number of CD34+ cells in the leukapheresis components of all groups were without statistical significance. In the Spectra group, the collection of MNCs of 104 percent and CD34+ cells of 154 percent was significantly more efficient than that in the MCS 3P group (42.2% and 56%, respectively) or the CS 3000 Plus group (50.8% and 47.15%) as related to the patients' blood volume. CONCLUSION: PBPC collection can be performed successfully with continuous-flow and intermittent-flow blood cell separators. The Spectra had the best recovery of CD34+ cells within the shortest time. Leukapheresis with the MCS 3P is indicated if only a single venous access is available.     

Second donation of granulocyte-colony-stimulating factor-mobilized peripheral blood progenitor cells: risk factors associated with a low yield of CD34+ cells

BACKGROUND: There are still limited data on the efficacy and safety of repeated donations of granulocyte-colony-stimulating factor (G-CSF)-mobilized peripheral blood progenitor cells (PBPCs) for allogeneic transplantation. STUDY DESIGN AND METHODS: Sixty-seven healthy donors undergoing two consecutive mobilizations of PBPCs within a median interval of 5 months (range, 0.1-47 months) were investigated. For both first mobilization (FM) and second mobilization (SM), G-CSF (lenograstim) at 7.5 microg per kg per day was administered. RESULTS: The nonhematologic side effects were comparable between both mobilizations. A significantly lower yield of CD34+ cells x 10(6) per kg of donor weight was obtained on Day 5 of SM in female (n = 31; FM, 5.0; SM, 3.23; p = 0.008) but not in male (n = 36; FM, 5.96; SM, 5.36; p = 0.24) donors. Multivariate analysis identified a lower CD34+ blood concentration on Day 5 of FM (p < 0.001) as well as female sex (p = 0.015) as independent risk factors for a lower yield of progenitor cells, whereas donor age and body mass index, interval between donations, and schedule of G-CSF application showed no significant impact. CONCLUSION: The identified risk factors allow the estimation of the efficacy of a SM in an individual donor before G-CSF administration, thus avoiding distress to both the donor and the recipient.     

Successful autologous peripheral blood stem cell collection using large volume leukapheresis in patients with very low or undetectable peripheral blood CD34+ progenitor cells

Autologous stem cell transplantation provides some patients with hematolymphoid and solid organ malignancies an opportunity for cure. Management of peripheral hematopoietic stem cell (HSC) collections differs among institutions, especially if a very low pre-procedure peripheral blood CD34+ cell count (PBCD34) is demonstrated. This study retrospectively analyzed results of large-volume peripheral HSC collections in 91 patients over approximately two years. Fifteen patients with PBCD34 < 10 × 10e6/l (eleven with undetectable PBCD34) were compared to 76 patients with higher counts on the first collection day (adequate mobilizers). The poor mobilizer group had significantly lower pre-collection WBC and platelet counts as well as collection yields. However, most patients with PBCD34 < 10 × 10e6/l (80 %) collected the minimum target for HSC transplant (2.0 × 10e6 CD34+ cells/kg) in <5 consecutive days of collection, and those who did collect the minimum successfully underwent autologous transplantation, with hematopoietic engraftment and long-term survival comparable to the adequate mobilizers. Successful HSC collection may often be achieved regardless of d 1 PBCD34 counts.     

Prediction of number of apheresis procedures necessary in healthy donors to attain minimally required peripheral blood CD34+ cells

BACKGROUND: Allogeneic peripheral blood stem cell (PBSC) transplantation is widely performed as a curative therapy for hematopoietic malignancies. Donors for PBSC harvest (PBSCH) are usually healthy subjects and undergo granulocyte–colony-stimulating factor treatment and apheresis procedures. A considerable proportion of donors experience poor mobilization, necessitating additional harvesting or marrow collection or remobilization. Although some characteristics have been reported to correlate with poor mobilization, they may not be taken into account in selecting PBSC donors. To protect healthy donors, it is preferable to predict the number of apheresis procedures needed for PBSCH before the procedure is initiated.
STUDY DESIGN AND METHODS: A retrospective cohort study of 83 subjects was conducted, using statistical models to predict the probability of obtaining a sufficient number of CD34+ cells (≥2.0 × 10⁶/kg) in the first to the third apheresis procedures and the probability of failure to obtain sufficient cells within three apheresis sessions. This study explored potential candidate factors in an ordinal probit regression analysis.
RESULTS: Significant factors predicting successful PBSCH were donor age, donor sex, and body weight difference between donor and recipient. The predictive model showed good agreement with the observed number of apheresis sessions. Simulation tables are presented with this model.
CONCLUSION: The statistical model developed to predict the number of apheresis procedures for PBSCH may be useful for planning PBSCH in clinical practice.