Long-term follow-up of aplastic anaemia.

Of 61 patients with aplastic anaemia (AA) diagnosed in our hospitals, 37 survived more than 2 years; actuarial survival of this latter group was 58%, with a median follow-up of living patients of 10.2 years. Laboratory and clinical data pertaining to these long-term survivors was scrutinized to determine the incidence of clonal disorders, which was identified in 43%. Morphological evidence of the myelodysplastic syndrome (MDS) was found in 13 (35%), including four cases of RAEB; four (11%) developed PNH. Of 23 patients studied, four showed karyotypic abnormalities, but these did not always coincide with morphological features of MDS. Although four patients now have completely normal blood and marrow morphology, and another had normal blood and marrow morphology at the time of death due to unrelated disease, the study confirms the high incidence of cytopenia and morphological abnormality, sufficient to justify a diagnosis of MDS, in patients with a history of AA. No definite survival plateau was identified. However, the natural history of MDS secondary to AA seems to be different to that of MDS arising de novo; the clinical course is relatively indolent, possibly implying a different biology.