Comparative Characteristics of Abnormal Karyotypes in Secondary Acute Leukemia

Abstract—

The analysis of quantitative and structural chromosome abnormalities in the bone marrow cells of 11 patients with secondary neoplasms of hematopoietic and lymphoid tissues was carried out. The abnormal karyotypes were established in all cases and evolution of clonal chromosome abnormalities in 27.3%. Despite different primary nosological groups of neoplasms of hematopoietic and lymphoid tissues and different therapy regimens, the presence of quantitative and structural chromosomal instability was typical for all cases; they led to complex (72.7%), unbalanced karyotypes (81.8%), among which composite (54.5%) and monosomal (36.4%) ones were identified. A total number of structural and quantitative chromosome abnormalities ranged from 1 to 13 in one karyotype. The chromosomes 11 and 22 were more often involved in the quantitative and structural rearrangements. Among the types of structural rearrangements, balanced and unbalanced translocations, deletions, inversions, isochromosomes, additional material of unknown origin, and derivatives of the chromosomes formed as a result of unidentified rearrangements were detected; among them, deletions (20.0%) and translocations (14.3%) prevailed. Marker chromosomes were found in 37.1% that were registered against the background of monosomies, deletions in 28.3%, and ring chromosomes in 5.7%. In two cases (after immunosuppressive or targeted therapy), the stages of development of complications of clonal chromosome abnormalities were proposed based on the similarity of the structure of quantitative and structural abnormalities: at the first stage, a balanced translocation occurs; at the second, a quantitative anomaly (chromosome trisomy) is added; at the third, an unbalanced structural rearrangement. Each karyotype contained quantitative and/or structural chromosome abnormalities that belonged to the group of unfavorable cytogenetic prognosis.