PERIPHERAL T-CELL LYMPHOMAS - CYTOKINE PROFILE AND CHARACTERISTIC INTERLEUKIN-4 AND TUMOR-NECROSIS-FACTOR ALPHA-DEFICIENCY

Because of the recent evidence of involvement of cytokines in the infl ammatory processes, cellular proliferation and host defence mechanism, we have measured the in vitro production of interferon-gamma (IFN-gam ma), interleukin (IL)-4, IL-6 and tumor necrosis factor-alpha (TNFalph a) from the phenotypically and histologically characterized ten periph eral T cell lymphoma (PTCL) cases. The immunophenotypic study had iden tified three gammadelta PTCL cases (CD3-CD4+CD8+, one case and CD3+CD4 -CD8, two cases). Mononuclear cells obtained from the lymph node cells of PTCL cases, irrespective of histologic type, were found to produce highly elevated levels of IFN-gamma and IL-6 both spontaneously and i n response to concanavalin A stimulations. However, IL-4 and TNFalpha production was characteristically decreased from cells obtained from b oth blood and lymph nodes. IL-4 and TNFalpha have a number of pleiotro pic activities in particular stimulation of various immune effector fu nctions. Their deficient production is an important indication of seve re immune dysfunction in this disease. However, the meaning of their d eficient production is currently unclear. It may be a loss of physiolo gic regulation within the cytokine network. On the contrary, elevated IFN-gamma and IL-6 production may be important in etiology, inflammato ry response or disease pathogenesis.