Cytogenetic abnormalities in patients with severe aplastic anemia.

ABSTRACT

BACKGROUND: Cytogenetic abnormalities have been described in a few patients with otherwise typical severe aplastic anemia (SAA), and the possible clonal nature of this disease is a controversial issue. MATERIALS AND METHODS: Sixty-nine patients with acquired severe aplastic anemia underwent cytogenetic examination on bone marrow cells at the time of diagnosis (n = 34) and/or at least twice after immunosuppressive therapy (IS) (n = 35). RESULTS: We identified 2 major groups. Group A 51 patients (74%) were normal and remained normal. Group B 18 patients (26%) had at least one abnormal cytogenetic analysis. This second group could be further subdivided as follows (B1) chromosomal abnormalities not present at first examination and acquired in the course of the disease (n = 7); (B2) clonal cytogenetic abnormalities present at first examination and persisting (n = 3); (B3) reversible cytogenetic abnormalities (n = 8). The most frequent abnormality was trisomy 8 (n = 8) followed by monosomy 7 (n = 2); 82% of patients are alive in group A and 61% in group B. Three patients developed acute leukemia, all from group B. This represents 4% of all patients or 17% of those with at least one abnormal cytogenetic test. CONCLUSIONS: Thus the majority of SAA patients have normal karyotypes in marrow cells at presentation and at follow-up. Patients with abnormal karyotypes exist and can be further subdivided into those with reversible and those with persistent abnormalities. The latter are at risk of developing myelodysplasia or acute leukemia.