High Levels of Soluble Immunoregulatory Receptors in Patients with WaldenströM’s Macroglobulinemia.

CD25, CD27, CD30 and CD40 are receptors for IL-2, CD70, CD153 and CD154, respectively, which provide important signaling for both B- and T-cell immune responses. We therefore examined the sera of patients with Waldenstrom’s macroglobulinemia (WM), a B-cell disorder characterized by excess IgM secreting bone marrow lymphoplasmacytic cells (LPC) for the presence of soluble CD25, CD27, CD30, CD40, IL-2, CD153, and CD154. Sera were from patients with active disease and off-therapy. Sera from healthy age matched donors (HD) was used for controls. The results of these studies were as follows:

Considering our recent studies demonstrating a role for mast cells (MC) in supporting WM cell growth (JCO 2004 22:571S), we examined bone marrow LPC along with MC from WM patients for expression of CD25, CD27 and CD40 and/or their ligands by flow cytometry and RT-PCR analysis. The results of these studies are as follows:

The above studies demonstrate high levels of circulating immunoregulatory receptors, and expression of these receptors and/or their ligands on WM tumor and mast cells. Studies addressing their role in immune dysregulation in WM are underway.