Chin Med J (Taipei) 1998;61:S127.

CD34(+) Stem Cells Transplantation in Malignancies

Chao-Sung Chang, Sheng-Fung Lin, Ta-Chih Liu, Shu-Mun Hwang, Tyen-Po Chen,

Division of Hemato-oncology, Kaohsiung Medical College Hospital

Abstract

Tumor relapse remains the major problems in those transplanted patients either by allogeneic bone marrow transplantation (BMT) or peripheral blood stem cells transplantation (PBSCT). Mechanisms to cause the tumor relapse are different in both. In PBSCT, tumor cells contamination in PBSCs collected might play an important role to cause tumor relapse. Evidence has shown these contaminated cancer cells has directly responsible for patient's relapse using genetic marking method. Hence, tumor purging became important to decrease the contaminated tumor cells. Both positive selection of CD34(+) stem cells and negative selection using cytotoxic agents or tumor specific antibody to reduce the contaminated tumor cells have seemed to be effective in previous reports. There exist the possible side effect of cytotoxic agents or antibody and complement to damage the stem cells in negative purging. Hence using a positive selection of CD34(+) cells might lessen this possible side effect. However, there still remained uncertainty in the efficiency of positive selection which might lose some stem cells during procedures. Herein we report our limited experience in CD34(+) stem cells transplantation in three malignant patients (2 non-Hodgkin's lymphomas and 1 stage IV breast cancer) using positive selection method. Our preliminary result showed the percentages of CD34(+) cells in the PBSC collects varied from 0.32% to 2.04% before positive selection and from 46.08% to 59.1% after positive selection, which has been concentrated from 29 to 144 folds. All patients were tolerable well to the conditioning regimen and achieved quick hematopoietic recovery. The mean days of white count recover to 1000/ul and platelet to 20000/ul were 12 days and 14 days, respectively. No specific complication was noted. The possible clinical application of CD34(+) cells transplantation will be discussed.

[Chin Med J (Taipei) 1998;61:S127.]