Cytokine expression in T-cell lymphomas and Hodgkin's disease. Its possible implication in autocrine or paracrine production as a potential basis for neoplastic growth.

The detection of an increasing number of cytokines and the demonstration of autocrine and paracrine mechanisms perpetuating tumor growth prompted the investigation of the expression of the cytokines IL-2, IL-3, IL-4, IL-5, IL-6, IFN gamma, Tac, and GMCSF in primary lymph-node biopsies of patients with peripheral T-cell lymphoma (n = 11), Hodgkin's disease (n = 13), and large-cell anaplastic lymphoma (n = 6) by means of Northern blot analysis and in situ hybridization (ISH); 15 of 28 cases had IL-6 message, predominantly in cases of Hodgkin's disease (HD) and large-cell anaplastic lymphomas (LCAL). Interferon gamma was found in about 50% of the cases among all entities. Other cytokine expression was rare except two cases of HD with high amounts of IL-4 mRNA. These results indicate that large amounts of growth factor transcripts are present in a variety of malignant lymphomas. The meaning of this expression is still unclear. It may be a loss of physiologic regulation within the cytokine network which may thus influence neoplastic cell growth as some cases have a quantity of cytokine expression which is similar or even above that of stimulated T cells. ISH demonstrates in individual cases that the expression is at least in part due to malignant cells.