OBJECTIVETo explore the effects of large dose of Astragalus membranaceus (Astragalus) on the dentritic cell (DC) induction in vitro and augumentation by peripheral mononuclear cell (MNC) and on antigen presenting ability of DC in children with acute leukemia.

METHODSForty-four children with acute leukemia in complete remission stage were divided into two groups. Twenty patients in the Astragalus (90 g daily) group were treated with large dose of Astragalus (90 g daily) based on conventional chemotherapy for one month, while 24 patients in the control group received chemotherapy alone. MNC were extracted from peripheral blood by wall-sticking method and cultured with such cell factors as interleukin-4, gramulocyte macrophage colony stimulating factor, tumor necrosis factor-alpha for 7-8 days. Phenotype of DC was assayed by flow cytometry and antigen presenting ability of them was assayed by mixed lymphocyte reaction.

RESULTSThere was no morphological difference in MNC induced DC between the two groups. The average number of DC in Astragalus group and control group was 4.4 x 10(6) / 2.5 x 10(6) MNC and 2.6 x 10(6) / 2.5 x 10(6) MNC, respectively, showing significant difference (P < 0.001). DC in Astragalus group could stimulate the proliferation of allogeneic lymphocytes strongly, showing significant difference when compared with that in the control group (P < 0.001). Conclusion Large dose of Astragalus could increase the DC induction of MNC and enhance the antigen presenting ability of DC in acute leukemia patients.