TEL/AML1 and immunoreceptor gene rearrangements—which comes first?

Received 10 August 2004; accepted 23 November 2004.

Abstract

TEL/AML1 fusion gene is present in 20–25% of childhood acute lymphoblastic leukaemias. In order to unravel at which stage of B-cell precursor development the fusion is originated, we analysed frequency and pattern of immunoreceptor (immunoglobulin and T-cell receptor) gene rearrangements in 47 TEL/AML1-positive and 43 TEL/AML1-negative cases of the same CD10+ immunophenotype. Moreover, we compared corresponding immunoreceptor gene rearrangements in 11 cases of TEL/AML1-positive leukaemia at diagnosis and relapse. More mature immunogenotype of TEL/AML1-positive cases and changes in 37% of rearrangements between diagnosis and relapse suggest that in most cases the TEL/AML1 fusion is formed during immunoreceptor gene rearrangement process.

Keywords: Acute lymphoblastic leukaemia, TEL/AML1, Immunoglobulin, T-cell receptor, Rearrangement, Relapse

a CLIP - Childhood Leukaemia Investigation Prague, 2nd Medical School, Charles University Prague, V Uvalu 84, Prague, Czech Republic

b Department of Paediatric Haematology and Oncology, 2nd Medical School, Charles University Prague, V Uvalu 84, 150 06 Prague 5, Czech Republic

c Department of Immunology, 2nd Medical School, Charles University Prague, V Uvalu 84, Prague, Czech Republic

Corresponding author. Tel.: +420 22443 6580; fax: +420 22443 6521.

PII: S0145-2126(04)00392-3

doi:10.1016/j.leukres.2004.11.007

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