[Comparative study on clinical features between TEL-AML1 positive and negative childhood acute lymphoblastic leukemia].
OBJECTIVE
To determine the incidence of TEL-AML1 fusion gene in childhood acute lymphoblastic leukemia (ALL) and to compare the clinical features between TEL-AML1 positive and negative patients.


METHODS
Samples of bone marrow or peripheral blood were collected from 95 newly diagnosed ALL children and the TEL-AML1 fusion gene was detected using nested reverse transcription-polymerase chain reaction (RT-PCR). The ALL patients were stratified into TEL-AML1 positive and negative groups and the clinical features were compared.


RESULTS
Among 95 patients, 20 (21.05%) were TEL-AML1 positive. The median age of TEL-AML1 positive patients was 5.9 years old and M/F ratio was 1.22:1. There were significant differences between TEL-AML1 positive and negative patients in hepatomegaly (2.75 cm vs. 4 cm below costal arch, P=0.006), splenomegaly (0 cm vs. 3 cm below costal arch, P < 0.001), initial white blood cell count (median 7.40 x 10(9)/L vs.18.70 x 10(9)/L, P=0.011), initial peripheral blood blast (median 2.45 x 10(9)/L vs.11.66 x 10(9)/L, P=0.013), hemoglobin level [(61.45 +/- 13.46) g/L vs. (75.89 +/- 23.11) g/L, P=0.003] and serum lactate dehydrogenase [(621.47 +/- 335.85) U/L vs.(1566.64 +/- 1720.45) U/L, P=0.020], while no differences were found between two groups in age, gender ratio, initial platelet count, percentage of blast in bone marrow, immunophenotypes and the expression of myeloid antigen CD13, CD33 and CD34. The prednisone sensitivity test showed that all 12 TEL-AML1 positive patients were good responders, while there were 11 prednisone poor responders among 40 negative patients (27.50%, P < 0.05). Bone marrow examination on day 15 showed no difference in the rate of complete remission between TEL-AML1 positive and negative patients.


CONCLUSIONS
The incidence of TEL-AML1 fusion gene in cases of ALL is 21.05%. The load of leukemia cells in TEL-AML1 positive patients is significantly smaller than its counterparts, and the blast cells in TEL-AML1 positive patients are more sensitive to prednisone, indicating childhood ALL with TEL-AML1 fusion gene has a favorable prognosis.
Guo
Xia
X
Department of Pediatrics, West China Second Hospital, Sichuan University, Chengdu, Sichuan, 610041 PR China.
Li
Qiang
Q
Zhu
Yi-ping
YP
Zhou
Chen-yan
CY
Gao
Ju
J
Li
Xi-hong
XH
Pan
Ling-li
LL
Li
Feng-yi
FY
Tian
Xin
X
Liu
Hai-ting
HT
D000293:Adolescent; D001853:Bone Marrow / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D050676:Core Binding Factor Alpha 2 Subunit / Q000235:genetics*; D005260:Female; D050939:Gene Fusion; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D010641:Phenotype; D010976:Platelet Count; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000097:blood / Q000235:genetics* / Q000276:immunology / Q000473:pathology*; D011241:Prednisone / Q000627:therapeutic use; D050783:Proto-Oncogene Proteins c-ets / Q000235:genetics*; D012313:RNA / Q000302:isolation & purification; D012097:Repressor Proteins / Q000235:genetics*; D000097764:ETS Translocation Variant 6 Protein
D050676:Core Binding Factor Alpha 2 Subunit; D011241:Prednisone; D050783:Proto-Oncogene Proteins c-ets; D012313:RNA; D012097:Repressor Proteins; D000097764:ETS Translocation Variant 6 Protein; C493728:RUNX1 protein, human