Micronuclei in erythropoietic bone marrow cells: Relation to cytogenetic pattern and prognosis in acute nonlymphocytic leukemia

The bone marrow karyotype and the frequency of micronuclei in erythropoietic bone marrow cells (Howell-Jolly bodies) were determined in 25 adults with acute nonlymophocytic leukemia (ANLL). Ten patients had exclusively normal diploid bone marrow cells; 11 had a mixture of normal and abnormal cells, and 4 had abnormal bone marrow metaphases only. The frequency of micronuclei ranged from 3 to 28/2000 erythropoietic bone marrow cells (median 10). The number of micronuclei was significantly higher in patients with abnormal metaphases than in those with normal metaphases; in patients with a mixture of normal and abnormal bone marrow metaphases there was an association between the frequency of abnormal metaphases and the number of micronuclei. A striking difference in median survival time was found between patients with low and high numbers of micronuclei, irrespective of the cytogenetic bone marrow patterns. Patients with fewer than 10 micronuclei per 2000 erythropoietic bone marrow cells had a median survival of 148 days; those with more than 10/2000 had a median survival of only 34 days (0.002 < p < 0.02).