IN-VITRO EXPANSION OF CD34-BLOOD OF MYELOMA AND LYMPHOMA PATIENTS( CELLS FROM PERIPHERAL)

We studied the feasibility of in vitro expansion of CD34(+) cells from patients with multiple myeloma (MM) or follicular non Hodgkin lymphom a (NHL). CD34(+) cells were selected from peripheral blood (PB) using avidin-biotin immunoadsorption columns: purified CD34(+) cells from th ree MM and five NHL patients were expanded. First, CD34(+) cells (2 MM , 4 NHL) were grown for 14 days in 5 ml of IMDM plus 12.5% horse serum (HS), 12.5% fetal calf serum (FCS) and a commonly used combination of cytokines: IL(1) alpha, IL(3), IL(6), SCF, GM-CSF, G-CSF (10 ng/ml ea ch) and EP (4 Ul/ml). In these conditions, at day 14, average increase in CD34(+), CFU-GM and total cell numbers were, respectively: x 6.0 x 23 and x 2,113 fold with 20 to 35% of granulocytic cells. In terms of CD34(+) cell, CFU-GM and total cell outputs, MM cultures were compara ble to NHL cultures, but MM cultures seemed to produce less granulocyt ic cells than NHL cultures. Next, in vitro expansion of PB CD34(+) cel ls was tested in culture media suitable for clinical use. Two cultures (1 MM, 1 NHL) were carried out for 14 days in 20 ml of X-Vivo 10 medi um, 2% human serum, IL(1) alpha, IL(3), IL(6), SCF, GM-CSF, G-CSF (6 n g/ml each) and EP (2 UI/ml). Increase in CD34(+), CFU-GM and total cel l numbers in these conditions were, respectively: x 5.7 and x 19.7, x 11.9 and x 40.9, x 424 and x 408 fold, with at least 75% of granulocyt ic cells in both cultures. We conclude that, although further improvem ents are necessary, in vitro expansion of PB CD34(+) cells can presuma bly be carried out successfully for MM patients as well as for NHL pat ients, including in conditions suitable for clinical use.