[Expression of CD25 in acute B cell lymphoblastic leukemia and its clinical significance]

This study was purposed to investigate the relation of CD25 with the acute B cell lymphoblastic leukemia (B-ALL) and its clinical significance. A totol of 88 newly diagnosed B-ALL patients were enrolled in this study. The immunophenotype of leukemic myeloblasts were detected by flow cytometry, including interleukin 2 receptor α chain (CD25), β chain (CD122), γ chain (CD132), CD19, CD20, CD10, CD34, CDIgM, CD79a, CD22 and CDTDT. The expression of BCR/ABL fusion gene was detected by qualitative PCR. The expression of IL2RA (CD25 gene) was detected by real-time qualitative RT-PCR. The results showed that there was no significant statistical difference in WBC count, Hb level, PLT count, marrow blast rate, peripheral blast rate, hepato-lienal infiltration, lymph node infiltration, levels of CD10, CD20, CD22, CD34, CD79a, CDTDT, CDIgM expression between B-ALL patients with CD25(+) and B-ALL patients with CD25(-), while the CD19 expression level in B-ALL patients with CD25(+) was higher than that in B-ALL patients with CD25(-). Out of 88 B-ALL patients, 21 patients showed BCR/ABL(+)(21/88) and their CD25(+) expression level was 66.7% (14/21); 67 patients showed BCR/ABL(-) and their CD25(+) expression level was 4.5% (3/67), there was statistical difference between these two groups (P < 0.05), but the expression level of IL2RA mRNA was not statistical different between CD25(+) and CD25(-) groups (P > 0.05). Among 21 BCR/ABL(+) B-ALL patients the remission rate and relapsed rate were not statistical different between CD25(+) an CD25(-) groups.In BCR/ABL(+) B-ALL patients 8 patients relapsed, the relapsed rate was 38.1% (8/21). In BCR/ABL(-) B-ALL patients 9 patients relapsed, the relapse rate was 13.4% (9/67), there was statistical difference between BCR/ABL(+) and BCR/ABL(-) two groups (P < 0.05). In BCR/ABL(+) group the RFS (relapse free survival) was 21 months, in BCR/ABL(+) CD25(+) patients the RFS was 15 months, while in BCR/ABL(+) CD25(-) patients the RFS was 21 months, in BCR/ABL(-) CD25(-) patients, the RFS was 24 months. It is concluded that the CD25 expresses at high level in B-ALL patients with BCR/ABL(+), which may serve as a predictive marker for the presence of BCR/ABL fusion gene, and relates with relapse, CD25(+) may serve as a adjuvant indicator for poor prognosis.