Increased Serum Soluble CD23 and Soluble IL-2R Levels in Haematologic Malignancies

Serum soluble CD23 (sCD23) and soluble IL-2 receptor (sIL-2R) levels increase not only in disorders with immune system activation, but also in hematological malignancies. They have been used as markers of disease progression and/or the response to therapy in lymphoproliferative disorders (LPD). In this study, we investigated the serum sCD23 and sIL-2R levels of 21 patients with different hematological malignancies [10 LPD, 6 multiple myeloma (MM), and 5 myelodysplastic syndrome (MDS)] before treatment, and compared them with 19 age- and sex- matched healthy subjects. Median sIL-2R levels were found to be significantly elevated in both the overall patient group and each of the subgroups. Median sCD23 levels were significantly higher in the overall patient group and in patients with LPD and MM. A positive correlation was found between sIL-2R and sCD23 levels in LPD. Our preliminary findings suggest that elevated serum levels of these soluble factors are not only markers of LPD but might be also used for other hematologic malignancies, except for MDS. Further studies should be designed to find out if it might be the result of an overactive immune system or not.