Increment of Suppressor T‐cells in Patients With Aplastic Anaemia

Recently, Kuriyama et a1 (1984) reported that the patients with aplastic anaemia who had a reduced ratio of T4 (helper/inducer-T) versus T8 (suppressor-T) responded well to immunosuppressive therapy.It has been well documented that aplastic anaemia may be induced by autoimmune injury of haematopoietic stem cells especially by suppressor T-lymphocytes (Camitta et aI, 1982).In clinical studies the effectiveness of immunosuppressive treatment of aplastic anaemia may suggest the evidence of the immune origin of aplastic anaemia (Gluckman et al, 1984).In order to clarify the presence of an immunological imbalance of aplastic anaemia, we have investigated peripheral blood lymphocyte subsets and the distribution of helper-inducer and suppressor-cytotoxic subsets among patients with aplastic anaemia.Lymphocytes were separated from heparinized whole blood by density gradient technique (Ficoll/sodium metrizoate).Monoclonal antibodies to all peripheral T cells (OKT3), to helper T cells (OKT4), to suppressor T cells (OKT81, to pan T cells (OKT11) (Ortho Diagnostics) and to B cells (B-1) (Coulter clone) were used and cell numbers were analysed by fluorescence activated cell sorter (FACS-IV).As shown in Table I, the percentage of helper-inducer T cells (T4 + ) was almost in a normal leveI compared to the normal controls and patients with aplastic anaemia in complete remission.In contrast a significant increment