THE SIGNIFICANCE OF WT1 GENE EXPRESSION IN DETECTION OF CHILDREN'S LEUKEMIA MINIMAL RESIDUAL DISEASE

Bai XL, Zhao HN, Yao H, et al

Jinan Milinary General Hospital, Jinan, China

 

Objective: To explore the wilms' tumor gene (WT1) expression in children with acute leukemia (AL) and the clinical significance for detecting minimal residual disease (MRD).

Methods: The WT1 mRNA expression levels in 52 AL children were examined by the nested RT-PCR and dynamiclly quantitative analysis was followed up in 29 cases with complete remission (CR).

Results: (1) The WT1+ expression was 68.5% in ALL, 80.0% in ANLL. The patients with 1.0 level of WT1 had significantly lower CR rate than those with 1.0 or undetectable level. (2)Dynamically detected after CR, 5 out of 6 patients with WT1 mRNA 0.3 relapsed, and only 5 out of 16 with negative WT1 mRNA or 0.3 relapsed (P<0.05). (3) 10 cases of WT1+ at diagnosis were still positive at relapse, in which 3 cases changed to positive from negative or had a higher expression at 1-3 months before clinical relapse. (4) 34 of those patients were detected WT1 expression levels in peripheral blood (PB) and bone marrow (BM) at the same time. The results were no difference. But the follow-up observation showed that the relapse rate was higher in PB positive patients. This indicated that PB for detection of MRD is more specificative than that of BM.

Conclusion: The WT1 gene abnormal expression was observed in majority of AL children, and can be used as a tumor marker of pan leukemia. The WT1 gene quantitative analysis can be used to monitor MRD and predict relapse and prognosis.

 
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