Quantization of CD34+ peripheral blood hematopoietic progenitors for autografting in cancer patients

After myeloablative regimens, combined reinfusion of peripheral blood hematopoietic circulating progenitor cells (CPC) and bone marrow, yields a very rapid hematopoietic recovery. Therefore, based on the knowledge that CPC express the CD34 and CD33 differentiation antigen, we have developed a direct immunofluorescence flow cytometry assay to detect the peak of CPC in the peripheral blood of patients treated with high dose chemotherapy and growth factors. This assay, compared to CFU-GM assay, has the following advantages: 1) easy to do 2) standardized method 3) real time information on CPC number. This work illustrates the practical aspects of this assay and substantiate the widespread use of the CD34/33 flow cytometry assay to guide harvesting of circulating hematopoietic progenitors for autologous transplantation.