Abstract
A79-year-old female of refractory anemia with ringed sideroblast is presented. Laboratory data showed macrocytic anemia with normal cellurality of bone marrow. Ringed sideroblasts were observed in about 25% of erythroblasts in bone marrow and the intramitochondrial iron deposition was ultrastructurally demonstrated.
Lymphocyte abnormalities have been described in myelodysplastic syndromes (MDS) including refractory anemia. The extent of the hematological abnormalities lead to the assumption that there may be a defect at the level of multipotential stem cell in MDS. However, it was not known whether or not there may be any relationship between lymphocyte abnormality and a defect of multipotential stem cell in MDS. We investigated various aspects of lymphocyte function in this patient. The number of T lymphocytes, T lymphocyte subsets and mitogen responses of peripheral blood mononuclear cells (PBMC) were almost normal, while NK cell activity and interleukin 2 (1L-2) production of PBMC from the patient were remarkably impaired. However, natural killer (NK) cell activity and 1L-2 production of this case were restored by depletion of plastic dish-adherent cells. Although the plastic dish-adherent cells were found to suppress NK activity and 1L-2 production of the patient's lymphocyte in the mixing experiments, these suppressions were restored only partially by the addition of indomethacin.
This results suggested the involvement of any mechanisms other than prostaglandin E in these suppressions. The roles of adherent suppressor cells in abnormalities of lymphocyte function in preleukemia also was discussed in the present paper.
