Cytokines and cutaneous T-cell lymphomas

Cytokines are considered to be of major importance for the pathogenesis of cutaneous T-cell lymphomas (CTCL). Their impact may result from autocrine, paracrine or endocrine effects. Several investigations demonstrated the overexpression of different cytokines in different CTCL entities. Interestingly, stage-dependent shifts in the cytokine pattern have been observed in mycosis fungoides (MF). There is evidence that the abnormal cytokine expression in CTCL might be responsible for tumor progression, resulting from an enhanced proliferation of the malignant cells and/or the depression of the anti-tumor immune response. Moreover, cytokine loops might explain phenomena like the epidermotropism of malignant cells or eosinophilia and increased plasma levels of IgE, which are present in advanced stages of CTCL. Analysis of the cytokine pattern in CTCL might give the basis for direct therapeutic intervention into the cytokine network as a new therapeutic approach. In this review the current knowledge regarding cytokines in CTCL is summarized.