Clinico-biological implications of increased serum levels of interleukin-8in B-cell chronic lymphocytic leukemia

Background and Objective. Constitutive cellular expression and serum releas e of biologically active interleukins (IL-8) has been reported in B-cell ch ronic lymphocytic leukemia (CLL). Given the autocrine role played by IL-8 i n the process of cell accumulation characteristic of this disease we tried to investigate clinico-biological implications of Increased serum levels of this cytokine in an unselected series of B-cell CLL patients. Design and Methods. Serum levels of IL-8 were determined at the time of dia gnosis in 58 previously untreated B-CLL patients using an immunoenzyme assa y. Results were correlated with main clinico-hematologic features as well a s with the risk of disease progression. Finally, we looked for associations between IL-8 and molecules directly involved in apoptosis, such as intrace llular bcl-2 and soluble APO1/Fas. Results. Increased serum levels of IL-8 were found in 15 out of 58 (25.8%) B-cell CLL patients. Serum levels of IL-8 did not reflect clinico-biologica l features representative of tumor mass such as clinical stage, histopathol ogic pattern of bone marrow (BM) involvement, beta(2)-microglobulin, sCD23 and sCD27 titers. Interestingly, circulating levels of IL-8 paralleled thos e of intracellular bcl-2 (r = 0.522; p = 0.01), thus confirming that the an tiapoptotic effect of IL-8 can be exerted through a bcl-2 dependent pathway . Levels of IL-8 did not match those of soluble Apo-1/Fas (r = -0.013; p = 0.943). Finally, stage A patients with levels of IL-8 above the median valu e (i.e. 4.5 pg/mL) were more likely to progress to a more advanced clinical stage than those with levels below the median value (p < 0.05). Interpretation and Conclusions. IL-8 is an interesting marker in B-cell CLL , closely involved in the pathogenesis of disease. Furthermore, it is usefu l for predicting the pace of disease progression in early clinical stages. (C) 1999, Ferrata Storti Foundation.