Stress induced changes in lymphocyte subpopulations and associated cytokines during whole body hyperthermia of 41.8-42.2 degrees C.

Extreme acute physical stress leads to transient impairment of T-lymphocytes, which are essential for tumor defence and prevention of infectious diseases. Radiant whole body hyperthermia (WBH) at 41.8-42.2 degrees C may enhance the efficacy of systemic chemotherapy in patients with advanced malignancies, but is associated with marked physical stress. Aim of this study was to demonstrate stress induced short-time effects on lymphocyte subpopulations and associated cytokines during WBH. Total leukocyte count, white blood cell differential blood count, lymphocyte subpopulations (T-helper-/T4-cells, T-suppressor-/T8-cells, natural-killer-/NK-cells, gammadelta-T-cells) as well as plasma levels of Interleukin(IL)-10, IL-12 and Interferon-gamma (IFN-gamma) were measured in ten patients treated with WBH and additional cytostatic chemotherapy. Blood samples were drawn before treatment, at three temperature points during WBH, and 24 h after start of treatment. Results were compared with those obtained from a control group consisting of six patients receiving chemotherapy alone. Numbers of T4-cells decreased significantly during WBH, while numbers of NK-cells and gammadelta-T-cells increased, resulting in transient impairments of total lymphocyte counts and T4/T8-ratio. IL-12 plasma levels as well as IFN-gamma/IL-10-ratio also decreased during WBH. No significant changes were found in T8-cells of WBH patients. Changes were reversible within 24 h and could not been found in control patients. Our results support the hypothesis that WBH combined with chemo therapy induces a strong but reversible anti-inflammatory stress response in cancer patients during therapy. Further studies are necessary to examine the pathophysiological details and to evaluate the meaning of these transient immunological changes for patient's outcome.