Evaluation of the COM.TEC cell separator in predicting the yield of harvested CD34+ cells

Combined peripheral blood monocyte count and white blood cell count as a guide for successful one-day autologous peripheral blood stem cell collection

INTRODUCTION

Peripheral blood stem cells (PBSCs) are the most common source of stem cell transplantation, which depends on an adequate number of CD34+ cells. Although pre-apheresis CD34+ cell count is a standard guide for the collection, it is not always available. This study aimed to evaluate complete blood count parameters for predicting successful one-day autologous PBSC collection.

METHODS

Data from the patients who underwent autologous PBSC collection at a tertiary care hospital were retrospectively reviewed.

RESULTS

There were 123 patients (185 leukapheresis procedures). Successful PBSC collection (CD34+ cells ≥4.0 × 106 cells/kg) was obtained in 85 patients (69.1%), of which 55 (44.7%) were successfully obtained on the first day. The median CD34+ collection efficiency was 44.1%. The mean platelet loss during apheresis was 39.9%. The adverse event rate was 18.9%. Patients in whom PBSCs were collected within one day were less likely to experience adverse effects related to leukapheresis. Pre-apheresis CD34+ cells ≥10 cells/μLand combined white blood cell (WBC) counts ≥5 × 109/L and/or monocyte ≥10% were independently associated with the successful one-day PBSC collection (adjusted odds ratio 24.06, 95% confidence interval [CI] 5.30-109.10, p < 0.001; and 6.94, 95% CI 1.35-35.79, p = 0.021, respectively). Only pre-apheresis CD34+ cells had a strong correlation with the total stem cell yield.

CONCLUSIONS

To reduce the complication of leukapheresis, the combined pre-apheresis WBC ≥5 × 109/L and/or monocyte ≥10% is a practical parameter to initiate a successfully one-day PBSC collection with or without pre-apheresis CD34+ cell results.

Autologous peripheral blood stem cell harvest: Collection efficiency and factors affecting it

BACKGROUND

Harvest of hematopoietic progenitor cells via leukapheresis is being used increasingly for transplants in India. Adequate yield of cells per kilogram body weight of recipient is required for successful engraftment. Collection efficiency (CE) is an objective quality parameter used to assess the quality of leukapheresis program. In this study, we calculated the CE of the ComTec cell separator (Fresenius Kabi, Germany) using two different formulae (CE1 and CE2) and analyzed various patient and procedural factors, which may affect it.

MATERIALS AND METHODS

One hundred and one consecutive procedures in 77 autologous donors carried out over 3 years period were retrospectively reviewed. Various characteristics like gender, age, weight, disease status, hematocrit, preprocedure total leukocyte count, preprocedure CD34 positive (CD34+) cells count, preprocedure absolute CD34+ cell count and processed apheresis volume effect on CE were compared. CE for each procedure was calculated using two different formulae, and results were compared using statistical correlation and regression analysis.

RESULTS

The mean CE1 and CE2 was 41.2 and 49.1, respectively. CE2 appeared to be more accurate indicator of overall CE as it considered the impact of continued mobilization of stem cells during apheresis procedure, itself. Of all the factors affecting CE, preprocedure absolute CD34+ was the only independent factor affecting CE.

CONCLUSION

The only factor affecting CE was preprocedure absolute CD34+ cells. Though the mean CE2 was higher than CE1, it was not statistically significant.

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.