Is there any difference in PBPC mobilization between cyclophosphamide plusG-CSF and G-CSF alone in patients with non-Hodgkin's lymphoma?

We attempted to analyze whether the use of high-dose cyclophosphamide (CTX 7g/m(2), group A) plus hematopoietic growth factor (G-CSF) or G-CSF alone ( 10 mug/Kg. group B) as a mobilizing regimen, could result in harvesting dif ferent numbers of CD34+ cells, committed progenitors and CD34+ cells subset s. The number of CD34+ cells considered as the target for each high-dose ch emotherapy was greater than or equal to 2 x 10(6)/Kg/bw. Fifteen leukaphere ses procedures were necessary in group A, while 16 procedures were performe d in group B. We did not observe any difference between the two groups in t erms of CD34+ cells/mul in the peripheral blood (117 vs 78; p=NS), whereas in the aphereses product we found a significant difference between the two groups of patients in terms of CD34+ cells (6.41 vs 2.89 x 10(6)/Kg/bw: p=. 009). CFU-GM (82.5 vs 52.3 x 10(4)/Kg/bw; p=.04). Interestingly, we noted a different distribution of CD34+/33- cells between the 2 groups (mean value 39% vs 65%, p<.05), whereas we did not find any differences regarding CD34 +/38-, CD34+/Thy1+, CD34+/HLADR-. The higher number of CFU-GM/Kg/bw collect ed in the former group did not translate into a superior plating efficiency (27.75 vs 30.29). Furthermore, we observed a strong correlation between CD 34+ cells/<mu>l in the peripheral blood and the total number of CD34+ cells in the leukaphereses product (r=0.97), whereas this correlation was not fo und in group B (r=0.15). In both groups of patients the number of CD34+ cel ls collected correlated well with CFU-GM (r=0.93; r=0.94), but definitely w e did not observe any correlation between CD34+ cells/mul and CFU-GM in pat ients mobilized with G-CSF alone and this did not allow us to predict the h arvest accurately. Finally, we evaluated the engraftment kinetics and we di d nor observe any statistically significant difference between the two grou ps of patients.