THE ABSOLUTE NUMBER OF CIRCULATING CD34(-CELLS THAT CAN BE COLLECTED BY APHERESIS() CELLS PREDICTS THE NUMBER OF HEMATOPOIETIC STEM)

We report our single institution's effort to standardize the method of collecting peripheral blood progenitor cells (PBPC) used for autologo us transplantation. PBPC were mobilized by different types of chemothe rapy followed by G-CSF (24 patients) or G-CSF alone (six patients) in 30 patients with various underlying neoplastic diseases, A median of t hree aphereses (range: 2-7), using the CS3000 cell separator was perfo rmed and a blood volume of 101 was processed, We studied the relations hip between the absolute numbers of circulating leukocytes, mononuclea r cells and CD34(+) cells and the amount of PBPC collected during a si ngle apheresis procedure, CD34(+) cells were quantified by leukocyte s ubset analysis based on flow cytometry, Both CFU-GM and CD34(+) cell c ontents of the apheresis products (69 procedures analyzed) correlated strongly: rho = 0.936, P = 0.0001), Regression analysis showed that th e total number of CD34(+) cells or CFU-GM content of the apheresis pro ducts could be predicted (r = 0.915, P = 0.0001) from the absolute num ber of CD34(+) cells in the blood, A number of 10 circulating CD34(+) cells per mm(3) blood ensured a minimum of 0.5 x 10(6) CD34(+) cells p er kg, collected on the same day, Of the 30 patients, 17 received an a utologous graft that contained only PBPC in 13, Long-term and complete hematological reconstitution was observed in all patients who had a m inimum of 2 x 10(6) CD34(+) cells per kg reinfused.