The detection of flow cytometric G-CSF receptor expression and it's effect on therapy in acute myeloid leukemia.

The aim of this study was to evaluate G-CSF receptor (G-CSFr) expression on myeloid blasts, its prognostic significance and role in growth factor use and the safety and efficacy of G-CSF in the treatment of AML. Expression of G-CSFr, CD11a, CD11b, CD11c, CD13, CD33 and CD34 were analyzed with flow cytometry in 101 patients with AML aged 15-60 years. Results were reported as a percentage of positive cells. G-CSFr expression rate was found to be higher in M2 and M3 but lower in M5, M6 phenotypes, and in secondary leukemia. Patients were randomized for G-CSF use. Of 101 cases 51 received G-CSF. The overall remission rate was 68.7%. G-CSF use did not seem to have any effect on the remission rates. The median time to reach neutrophil counts > or = 1000/microliter in cases receiving G-CSF was 23 days, and 28 days in the control group (p < 0.01). G-CSF significantly reduced the number of febrile days (p < 0.01). Early and late relapses of 8 and 16 were observed during follow-up which was not effected by G-CSF use. In patients who were G-CSFr(+), G-CSF use did not alter overall survival rate. Univariate and multivariate analysis have revealed that not sex, G-CSF use or G-CSFr but age, FAB subtype and performance status at diagnosis were the important factors on both overall and disease free survival. We have demonstrated no beneficial effect of G-CSFr analysis on in vivo G-CSF use.