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.