Assuntos
Biomarcadores Tumorais , Biópsia Líquida , Linfoma Difuso de Grandes Células B/diagnóstico , Ácidos Nucleicos Livres , DNA de Neoplasias , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Biópsia Líquida/métodos , Biópsia Líquida/normas , Linfoma Difuso de Grandes Células B/sangue , Linfoma Difuso de Grandes Células B/genética , Mutação , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Sensibilidade e Especificidade , Análise de Sequência de DNARESUMO
Results of recent studies with animal models suggest that expression of MLL fusion proteins promotes acute leukemogenesis. However, the most potent MLL fusion proteins are not sufficient for the development of acute myeloid leukemia (AML). The clinical data on the pathogenesis of this type of leukemia are limited. We analyzed the case of a patient with therapy-related AML with MLL rearrangement. The patient initially developed AML with t(8;21). Although the patient achieved complete remission with chemotherapy, an abnormal karyotype, inv(11)(q21q23), was detected. After 6-year persistence of a clone with the inversion 11 karyotype in the bone marrow, secondary AML developed. Results of fluorescence in situ hybridization analysis combined with magnet-activated cell sorting analysis showed that MLL rearrangement was detected in CD34+ and CD13+ fractions but not in a CD3+ fraction of the bone marrow. There were 2 important clinical findings. One was that MLL rearrangement was not sufficient for the development of leukemia. The other was that MLL rearrangement targets specific lineages.
