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Polyclonal haemopoieses associated with long‐term persistence of the AML1‐ETO transcript in patients with FAB M2 acute myeloid leukaemia in continous clinical remission
Author(s) -
GUERRASIO ANGELO,
ROSSO CLAUDIA,
MARTINELU GIOVANNI,
COCO FRANCESCO LO,
PAMPINELLA MARIA,
SANTORO ALESSANDRA,
LANZA CARLO,
ALLIONE BERNARDINO,
RESEGOTTI LUIGI,
SAGLIO GIUSEPPE
Publication year - 1995
Publication title -
british journal of haematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.907
H-Index - 186
eISSN - 1365-2141
pISSN - 0007-1048
DOI - 10.1111/j.1365-2141.1995.tb05160.x
Subject(s) - chromosomal translocation , biology , polyclonal antibodies , bone marrow , haematopoiesis , minimal residual disease , myeloid , cytogenetics , myeloid leukemia , immunology , gene , medicine , antibody , chromosome , stem cell , genetics
Summary. The t(8;21) (q22;q22) translocation is a recurring chromosomal abnormality observed in about 20‐40% of AML patients with subtype FAB M2 (AML‐M2). The molecular facet of this translocation is represented by the formation of a new hybrid gene, the AML1‐ETO, which is regularly transcribed in a chimaeric mRNA and translated into a new fusion protein believed to have a key role in the pathogenesis of this type of leukaemia. We looked for the presence of AML1‐ETO transcripts, by RT‐PCR, in 49 unselected patients affected by AML‐M2 diagnosed at various Italian Institutions. A hybrid transcript was detected in 11 cases (23%). Minimal residual disease status was investigated in three patients in continuous complete remission (CCR) after a median follow‐up of 44 months; at least one sample from each subject was found positive for the AML1‐ETO transcript suggesting a long‐term persistence of t(8;21) leukaemic cells. In two female patients in CCR a‘clonality’analysis was performed on peripheral blood DNA by exploiting the × chromosome inactivation pattern of the human androgen‐receptor gene (HUMARA); in both cases the results were consistent with the presence of a polyclonal haemopoiesis. Our data confirm that the persistence of residual cells expressing the AML1‐ETO transcripts is a frequent occurrence even in patients with long‐term remission; on the other hand, clonality assays indicate that in t(8;21) leukaemias long‐term remission haemopoiesis is sustained by a polyclonal bone marrow reconstitution.