[Analysis of 21 children with acute non-lymphoid leukemia carrying AML1/ETO fusion gene].

OBJECTIVE: It was revealed that t(8; 21) (q22; q22) was one of the most common chromosomal aberrations in acute non-lymphoid leukemia. The translocation was found to be involved in the AML1 gene on the chromosome 21 and the ETO gene on the chromosome 8, and resulted in the formation of AML1/ETO fusion gene on the derivative chromosome 8. The fusion gene was a transcription factor and played a direct role in the leukemogenesis. The translocation was mainly observed in M(2), accidentally in M(4) and M(1) and rarely in MDS. Here we studied the main clinical data in children with acute non-lymphoid leukemia (ANLL) carrying the AML1/ETO fusion gene. In addition, we discussed the significance of the detection of AML1/ETO fusion gene in the diagnosis and prognosis of children with ANLL.

METHODS: The authors investigated 29 patients in our hospital from December 2000 to March 2002. The patients were divided into two groups. Group A included 21 patients, 14 males and 7 females. They were 3.6 to 14 years old and the median was 9. Group B included 8 patients, 6 males and 2 females. They were 0.8 to 14 years old and the median was 6. Diagnosis was made according to FAB and MIC criteria and the expression of AML1/ETO fusion gene was detected with nested RT-PCR. The patients were treated according to DA, DAE or BFM regimen, respectively. The main clinical indexes including age, Hb, white blood count, platelet, blasts in PBC and BM, and time of arrival at complete remission (CR), were compared statistically between the two groups with t test of independent samples.

RESULTS: All the 21 patients in group A were found carrying AML1/ETO, and 17 patients (81%) were classified as M(2), the other 4 cases were of M(2) developed from MDS-RAEB-T, M(4Eo), M(5) and eosinophil leukemia, respectively. Eighteen out of 20 patients whose effects could be assessed reached CR, and the CR ratio was 90%. Two patients in group B were of AML-M(1), 3 M(2), 1 M(3), 1 M(4), and 1 M(5), respectively. None of them was found carrying AML1/ETO. Seven cases reached CR and the ratio was 87.5%. There was no significant difference between the two groups in the above clinical indices.

CONCLUSIONS: Between the two groups of patients there was no significant difference in the above clinical indices. RT-PCR for the detection of AML1/ETO in children with ANLL was quick, convenient and sensitive, and could be regarded as a useful method for the diagnosis and prognosis of ANLL.