Role of Cellular Immunity in Relation to the Specific Hematological Features in Atypical Leukemia

Abstract

Characteristics of cellular immunity in atypical leukemia was investigated in order to clarify the role of immunocompetent cells to the development of unusual and unique hematological features of this particular type of leukemia. The results are summarized as follows.
1) Higher positive rate of tuberculin test was demonstrated than that in overt leukemia, which suggested a well-preserved hypersensitivity reaction to recall antigen.
2) Circulating lymphocytes showed normal subpopulation constitutions, normal rate of T-cell subsets and normal phytomitogen responsiveness, despite a presence of lymphocytopenia. These results indicated a well-maintenance of lymphocyte populations and constitutions.
3) An increase in phytomitogen response of lymphocytes following 7 days' unstimulated preincubation was within the normal range, which meaned a presence of residual physiological suppressor cells.
4) Suppressive effects by co-cultured patients' circulating lymphocytes was demonstrated on the growth of allogeneic normal CFU-C and PWM-induced Ig production of allogeneic normal lymphocytes. The results suggested a well-preserved ability to induce suppressor lymphocytes in response to various immunological stimulations including blood transfusion.
5) A slight suppressive effect on the own abnormal CFU-C colony and cluster formations (leukemic growth) was shown by co-cultured autologous T-cells. The results suggested surviving of intercellular control mechanism between immunocompetent cells and leukemic clone in this type of leukemia.
6) NK cell activity against cultured cell line of human origin (K-562) was within or close to the normal ranges. The results indicated a persistence of NK effector activity in contrast to its nearly absence in overt leukemia.