title: T-cell qualities of lymphocytes and/or leukemic cells from peripheral blood in acute myeloid and lymphatic leukemia before treatment and at relapse.
abstract: PHA stimulation of peripheral blood lymphocytes and/or leukemic cells has been studied in 65 patients with acute leukemia before any prior treatment. There were 38 patients with A.L.L. and 27 with A.M.L. In relapsing A.L.L. 15 observations were made before reinduction therapy. In about 40% of all the cultures PHA stimulation was done simultaneously with PWM-stimulation. Before any treatment normal lymphocytes showed a normal response, being however somewhat diminished at relapse. Most of the cases of A.M.L. had so many leukemic cells in peripheral blood that no reliable measure of stimulation of the few lymphocytes left was possible. In A.L.L. this was however possible in about 30% of all the cases studied. In cultures of the predominantly leukemic cells, lymphoblasts showed a positive response in a minority of cases studied. If the peripheral WBC-count was high, a response was usually absent. In some of the cases of A.M.L., the leukemic cells reacted to PHA and PWM. Unexpected but very remarkable is our finding that in the control cultures, without added mitogen, the incorporation of labelled 3H-thymidine was usually very high in A.M.L. contrasting with A.L.L. leukemic cells who incorporated very little of the label. These striking differences were observed both in 72 and 144 hours cultures and were not caused by differences in viability between these two leukemic cell-types. The capacity of A.L.L.-leukemic cells to form E ("T") and EAC ("B") rosettes was studied in 20 cases. The percentages of rosette forming lymphoblasts differed widely from patient to patient. It is concluded that in A.L.L. leukemic cells are in a minority immuno-competent cells and it is suggested that the lymphoblast is an immature cell, arrested in the maturation towards a T-lymphocyte, the degree of maturity differing from patient to patient. Furthermore the striking difference in spontaneous labelling of myeloid versus lymphoblastic leukemic cells seems to be helpful in the differential diagnosis and may in part explain the well known differences in prognosis and behaviour towards cytostatics between these main leukemia types.
mesh_terms: D000293:Adolescent; D000328:Adult; D002469:Cell Separation; D002470:Cell Survival; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007104:Immune Adherence Reaction; D007223:Infant; D007945:Leukemia, Lymphoid / Q000276:immunology* / Q000628:therapy; D015470:Leukemia, Myeloid, Acute / Q000276:immunology* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D013601:T-Lymphocytes / Q000276:immunology*