Semenzato G, Trentin L, Zambello R, Agostini C, Bulian P, Siviero F, Ambrosetti A, Vinante F, Prior M, Chilosi M
Padua University School of Medicine, Department of Clinical Medicine, Italy.
Leukemia. 1988 Dec;2(12):788-92.
High levels of soluble IL-2 receptor (sIL-2R) are detectable in the serum of HCL patients. To determine the cell source of this molecule, we evaluated the presence of sIL-2R in the supernatants obtained from in vitro cultures of leukemic (hairy cell, HC) and non-leukemic lymphocytes from six untreated HCL patients and from an additional four patients under therapy with rIFN-alpha 2. We demonstrated that cultured HCs at resting conditions were able to spontaneously release the sIL-2R, whereas control enriched B cells did not. This phenomenon was present only when culturing HCs recovered from patients observed at the time of diagnosis but was not observed during treatment with rIFN-alpha 2. Following activation in vitro with a series of different stimulatory agents including BCGF, phorbol myristate acetate, and anti-human IgM antibody, cultured HCs increased their capability to shed the IL-2R molecules. On the other hand, the release of sIL-2R from enriched T cell populations from HCL patients did not significantly differ from the value obtained in controls. Taken together, these findings provide evidence that leukemic B cells represent the main source of sIL-2R in HCL patients and further emphasize the importance of evaluating this parameter as a relevant marker for monitoring the effectiveness of rIFN-alpha 2 therapy.
