PubMed2001
Analysis of T lymphocyte subsets made a great progress in attempting their important role in host defence against malignant disease. As the major regulatory elements in the immune system, helper (CD4+) and suppressor (CD8+) T cells are required for recognizing a large scale of surface antigen on tumor cells and subsequently, for mediating the regression of cancers. Many data suggest that T cell immunity system is not intact in different malignant diseases. The malignant disorders of hemopoietic tissue are frequently associated with T cell functional impairment, the mechanism(s) of which is still unresolved. In recent years, defects in immunoregulatory T cell network have been repeatedly proposed as the cause of this alteration and might be considered as a parameter of immunodeficiency in those patients. The additional disturbance of T cell immunoregulatory system may be induced by different extrinsic factors. In this context the chemotherapeutic agents with their non-selective action, including an immunomodulatory activity, should be involved in the evaluation of lymphocyte subset changes during treatment. In this brief review we analyzed the data concerning the T cell subset changes, both numerical and functional, before and in course of the treatment of patients with different hematologic malignancies. According to this consideration, it might be suggested that the immune system of these patients have some capacity to recover from the suppressive effect of chemotherapy, although not sufficiently to be normalized. The long-term monitoring of a larger scale of immunological parameters may probably help us to resolve whether T lymphocyte subset changes are related only to the therapy or, in some instance, might be connected with compromised natural host defence mechanisms in oncohematologic patients.