The effect of high-dose methylprednisolone combined chemotherapy on CD34-positive cells in acute lymphoblastic leukemia.

The expression of CD34 antigen on the surface of bone marrow cells during remission induction was studied in 27 selected acute lymphoblastic leukemia (ALL) patients who were CD34 negative at presentation and were stratified to receive high-dose methylprednisolone (30 mg/kg/day po) or conventional-dose prednisolone (2 mg/kg/day po). Patients received either induction with L-Asparaginase, vincristine (VCR), and high-dose methylprednisolone [HDMP, 30 mg/kg/day po for 1 week, 20 mg/kg/day po for 1 week, and 20 mg/kg/day po every other day for 2 more weeks (20 patients)], or identical induction in which HDMP was replaced by prednisolone 2 mg/kg/day by mouth for 4 weeks (8 patients). Bone marrow cells from all patients were studied 1,2, and 4 weeks after initiation of treatment for expression of the CD34 antigen using a three-step indirect immunoperoxidase staining technique. In the 20 patients with ALL who received HDMP the percentage of normal bone marrow cells expressing CD34 was significantly higher (p < 0.05) than in the 8 patients who did not receive HDMP. The mean percentage of CD34-positive bone marrow cells during the fourth week was 17.2% in patients with ALL who received HDMP, whereas patients who received 2 mg/kg prednisolone per day had only 6.1% CD34 cells in the marrow. Absolute polymorphonuclear leukocyte (pmnl) count was also significantly higher in the patients who received HDMP in the second and third week of therapy [(absolute pmnl count was 2197.7/mm3 in the second week and 4091.8/mm3 in the fourth week in the patients who received HDMP compared to 974.4/mm3 and 1556.5/mm3 in the patients who did not receive HDMP) (p < 0.05)].(ABSTRACT TRUNCATED AT 250 WORDS)