[Clinical features of atypical refractory anemia (RA)]

Twenty-three patients with bicytopenia or pancytopenia were retrospectively studied. The patients with underlying disorders, blast count of more than 5% on bone marrow (BM) aspirate, blast count of more than 1% on peripheral blood or ringed sideroblast count of more than 15% on BM aspirate were excluded. According to Yoshida's criteria, 23 patients were classified into 6 subtypes [AA (aplastic anemia)1: typical AA, AA2: atypical AA, MDS (myelodysplastic syndrome)3: typical RA (refractory anemia, MDS4-6: atypical RA], and AA1 7 cases; AA2 2 cases; MDS3 5 cases; MDS4 1 case; MDS5 2 cases; MDS6 6 cases. To clarify the clinical features of atypical RA group (MDS4-6), we investigated ferrokinetics, RBC life span, karyotype, serum Epo (erythropoietin) concentration, response to therapy and prognosis. Results were as follows: 1) all three RA patients who were younger than 30 years old were included in atypical RA group, 2) in ferrokinetics study PID (plasma iron disappearance time) values of MDS4 and MDS6 patients ranged between those of AA1 and those of MDS3 patients (5 of 7 patients), 3) two cases who developed leukemia belonged to typical RA group, 4) patients with atypical RA showed response to therapy and their prognosis were better than those with typical RA. These observations suggest that atypical RA have different clinical features from typical RA.