EFFECT OF DIFFERENT APHERESIS TECHNIQUES ON STEM CELL YIELD IN PERIPHERAL BLOOD STEM CELL (PBSC) TRANSPLANT PATIENTS

Abstract

Haematopoietic stem cell transplantation (HSCT) is a well-established treatment modality for a variety of bone marrow failure states.Numerous advances have taken place •in the field of HSCT over the past 10 years to make the procedure safer. The most significant change has been the use of peripheral blood stem cells (PBSC) as an alternative source ofhaematopoietic stem cells. Peripheral blood stem cell transplantation (PBSCT) results in faster engraftment of both platelets and neutrophils, leading to a shorter length of hospital stay, fewer days of fever, and less antibiotic use.

Different protocols of mobilization and harvesting techniques have been performed. High dose chemotherapy with haematopoietic progenitor cells support is now being administered increasingly to selected categories of patients with haematological malignancies & non haematological malignancies as cancer breast and lung cancer. Timing of harvesting is of utmost importance for minimizing cost and time-consuming steps and increasing quality and effectiveness of harvest product. The harvest product is collected and manipulated according to the standard protocols for stem cell cryopreservation and storage. Our study showed that large volume technique with heparin resulted in a higher CD34+ cell yield/kg when compared to the standard volume technique (P value = 0.01). A comparison was done between blood pictures before and after harvesting. As regards the two techniques of blood volumes processed. A significant difference in Hb g/dl (p value = 0.023) and hematocrite % (P value = 0.035) was found when using the large volume technique. A significant positive correlation was found between the preharvest absolute CD34+ cells/cmm and the yield ofCD34+ cells x 106/kg using the large volume technique (P value< 0.001).

In conclusion, the data in this study proves that the collected CD34+ cells amount is dependable on the technique of leukapheresis used showing the superiority of large volume over small volume technique. Also flow cytometric quantification of CD34+ cells/cmm in peripheral blood prior to harvesting of stem cells proved to be a good indicator of the CD34+ cells/ kg yield.