[Clinical significance of CD34(+)CD38(+) and CD34(+)CD38(low/-) subgroups in bone marrow of patients with B lymphoblastic leukemia].

This study was purpose to investigate the biological characteristics of B lymphoblastic leukemia (B-ALL) between CD34 positive CD38 positive (CD34(+)CD38(+)) and CD34(+)CD38(low/-) subgroups and their clinical significance. Immunophenotyping of B cells in bone marrow of 54 patients with newly diagnosed CD34(+)B-ALL were analyzed by 4 color multiparametric flow cytometry (FCM). According to the different expression of CD38, the newly diagnosed patients with B-ALL were divided into two groups: CD34(+)CD38(+) subgroup and CD34(+)CD38(low/-) subgroup. BCR-ABL, TEL-AML1 fusion genes and WT1 gene were detected by real time RT-PCR simultaneously. After chemotherapy, minimal residual disease (MRD) was monitored by one tube of 7 color FCM. The average follow-up time was 12 months (range 1 - 28), the average follow-up interval was 2 months (range 1 - 5). The results showed that there was no significant differences such as WBC, Plt count and Hb level between the two groups at diagnosis, the positive rate of BCR-ABL, TEL-AML1 and WT1 gene was also no significantly different. After clinical complete remission (CR), MRD positive (MDR(+)) case rates were 28.57% (10/35) in CD34(+)CD38(+) subgroup and 68.42% (13/19) in CD34(+)CD38(low/-) subgroup (P < 0.01). The relapse rate between the two groups was 5.71% (2/35) in CD34(+)CD38(+) subgroup (relapse time at 94 and 245 d respectively) and 36.84% (7/19) in CD34(+)CD38(low/-) group [median relapse time was 263 d (range 46 - 468), P < 0.01]. The age distribution was analyzed in these two subgroups (> 16 or ≤ 16 years old), there was 8 (8/35) adult patients (> 16 years old) in CD34(+)CD38(+)group and 10 (10/19) adult patients in CD34(+)CD38(low/-) group (P < 0.05). It is concluded that CD34(+)CD38(low/-) phenotype is more often presented in adult patients and the CD34(+)CD38(low/-) patients with B-ALL are more likely to have MRD(+)and relapse after treatment.