The possibility that G-CSF recruits leukemic cells from the G0 to S phase, which may lead to a greater susceptibility to cytotoxic drugs, such as ara-C, has been presented in Harada's study.

In this study, we referred to the protocol of Harada et al 1 to try G-CSF combined marrow-ablative chemotherapy and autologous PBSCT, for the treatment of AML patients in CR1 status. Between January 1997 and March 1998, six AML patients (3: children, 3: adults) in CR1 status were autografted and followed up to 3 years.

The major regimen related toxicity was composed of mucositis and diarrhea without death. The time of ANC recovery to 500/L and 1,000/L was 11~48 and 16~81 days, respectively. The mean time of platelet recovery to 20,000/L and 50,000/L was 21~233 and 35~370 days, respectively. The platelet recovery time to 50,000/L was markedly prolonged for more than 100 days in four patients (66.7%). Moreover, four patients (66.7%) experienced a relapse of leukemia after transplantation, with a mean interval of 147.5 days after PBSCT. Two patients were in CR status for 53 and 51 months after PBSCT, respectively.

The G-CSF combined marrow-ablative chemotherapy and autologous PBSCT resulted in a markedly delayed platelet recovery and no advantages for decreasing the relapse rate of AML. But, further studies will be warranted.