concanavalin-a and Preleukemia

Previously, cloning efficiencies and mitogenic responsiveness of lymphocytes from patients with preleukemic disorders were shown to be significantly depressed. Whole blood T lymphocyte colony formation and 3H-TdR incorporation were used to assess the effects of interleukin-2 (IL-2) and thymopoietin (TP-5) on the proliferation of lymphocytes from patients with preleukemia. There were no statistically significant differences (p greater than 0.05) between any of the test groups stimulated with mitogen alone when compared to groups stimulated with mitogen plus TP-5 and/or IL-2 in either assay system for either patient or control groups. Nevertheless, TP-5 and IL-2 markedly increased the cloning efficiency and mitogenic responsiveness of lymphocytes from many of the patients studied, but in no case restored the proliferation response to the level of mitogen stimulated control lymphocytes. These findings suggest that other soluble mediators/factors may be needed to fully compensate for deficient mitogenic responsiveness and colony formation of lymphocytes from patients with preleukemic disorders which may be multifactoria in origin. Of importance, enhancement of lymphocyte responsiveness to PHA/Con-A with TP-5 and IL-2 suggests the presence of maturational/functional defects in lymphocytes from some of these patients which may be compensated for in part by addition of TP-5 and IL-2.

Topics: Adult; Cells, Cultured; Colony-Forming Units Assay; Concanavalin A; Humans; Interleukin-2; Lymphocyte Activation; Lymphocytes; Middle Aged; Phytohemagglutinins; Preleukemia; Thymopoietins; Thymus Hormones

The responses to the T-cell mitogens Phythemagglutinin (PHA) and Concanavalin A (Con A) and the natural killer (NK) cell activity are tested in patients with preleukemia (PL). The results are compared with those of healthy controls. The PL patients show low responses to T-cell mitogens and low NK cell activities. It is discussed that the data are not of prognostic value in PL as to development of overt leukemia. However, the results suggest that PL impaired cell functions are not limited to erythropoiesis, granulopoiesis, and thrombopoiesis but are also found in the immune system.

Topics: Adolescent; Adult; Aged; Concanavalin A; Female; Humans; Killer Cells, Natural; Male; Middle Aged; Phytohemagglutinins; Preleukemia; Prognosis; T-Lymphocytes

A patient with constitutional Fanconi-like aplastic anemia who developed a preleukemic state was transplanted with bone marrow from his HLA-identical MLC-negative brother. Before transplantation his mononuclear leukocytes were found to have a defective stimulating and responder capacity in mixed leukocyte culture with cells of an unrelated individual. After removal of T cells the stimulating capacity was completely restored. MLC testing with separated cell fractions seems important to establish HLA-D identity with a possible donor, especially when MLC tests with unseparated cells are negative.

Topics: Adult; Anemia, Aplastic; Bone Marrow Transplantation; Cell Separation; Concanavalin A; Humans; Lectins; Leukocytes; Lymphocyte Culture Test, Mixed; Male; Preleukemia; T-Lymphocytes