MOBILIZATION OF PERIPHERAL-BLOOD PROGENITOR CELLS FOLLOWING CHOP TREATMENT COMBINED WITH DELAYED GRANULOCYTE-COLONY-STIMULATING FACTOR ADMINISTRATION IN PATIENTS WITH NON-HODGKINS-LYMPHOMA

The kinetic change in peripheral blood progenitor cells (PBPC) during 3 to 6 cycles of standard CHOP regimen supported with human recombinan t granulocyte colony-stimulating factor (rG-CSF) was investigated in t hree patients with newly diagnosed intermediate grade, diffuse large c ell type, non-Hodgkin's lymphoma (NHL) without bone marrow invasion. P atients were given rG-CSF subcutaneously (2 mu g/kg/day) initiated whe n total leukocytes was <3.0 x 10(9)/l. When the leukocyte count remain ed at >3.0 x 10(9)/l, rG-CSF was started 10 days following the prior C HOP. Treatment with G-CSF was discontinued after the leukocyte count r eached >10.0 x 10(9)/l, and CHOP was started the next day (CHOP-G regi men). The number of PBPC was monitored by clonal assay in patients 1-3 . No severe leukopenia with <0.5 x 10(9)/l of neutrophils was seen in any patient. Colony-forming unit granylocyte-macrophage (CFU-GM) signi ficantly increased after 2-3 days of consecutive administration of rG- CSF. The magnitudes of maximum amplification of CFU-GM in patients 1, 2, and 3, were 56-fold (during 3 cycles of CHOP-G), 216-fold (during 2 cycles), and 67-fold (during 4 cycles), respectively, and the absolut e numbers of the maximum CFU-GM/ml blood were 983, 7,568, 9,865, respe ctively. In one patient who was given 6 cycles of CHOP-G, the peak val ues of mobilized CFU-GM in each cycle did not substantially decrease u ntil 6 cycles of CHOP-G had been completed. Thus, the CHOP-G regimen d escribed here seems to be very efficient increasing the circulating CF U-GM prior to harvesting PBPC.