Circulating levels of cytokines and soluble cytokine receptors in various T-cell malignancies.

BACKGROUND: Cytokines, interleukin (IL)-4, IL-6, interferon-gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha), soluble CD23 (sCD23), and soluble IL-2 receptors (sIL-2R) are mediators of inflammation and immune response. Alterations in immune status of patients with various cancers may result in release of cytokines in circulation. The authors measured the circulating levels of IL-4, IL-6, IFN-gamma, TNF-alpha, sCD23, and sIL-2R from patients with T-cell chronic lymphocytic leukemia (T-CLL), T-cell acute lymphoblastic leukemia (T-ALL) and peripheral T-cell lymphoma (PTCL) to determine their importance in these T-cell disorders.

METHODS: IL-4, IL-6, IFN-gamma, TNF-alpha, sCD23, and sIL-2R levels were measured from the serum samples by enzyme-linked immunosorbent assay or bioassay methods.

RESULTS: IL-4 levels were higher only in T-CLL, whereas, IFN-gamma and sIL-2R levels were higher in T-CLL and T-ALL. However, IL-6, TNF-alpha, and sCD23 levels were higher in PTCL.

CONCLUSIONS: T-cell-derived IL-4 and IFN-gamma in T-CLL may act as an autocrine growth factor for proliferation of neoplastic T-cells. The sIL-2R levels in T-CLL, T-ALL, and PTCL are an indication of the degree of T-cell or immune activation due to concomitant immunologic processes in these disorders. However, IL-6, TNF-alpha, and sCD23 levels may contribute to inflammatory response and provide evidence of monocyte/macrophage, T-cell, or B-cell aberrations in PTCL.