Circulating Soluble Receptor Activator of Nuclear Factor Kappa B Ligand and C-C Motif Ligand 3 Correlate With Survival in Patients With Waldenström Macroglobulinemia.

Background: Serum receptor activator of nuclear factor κB ligand (sRANKL) and chemokine (C-C) motif ligand 3 (CCL-3) have been reported to be elevated in Waldenström macroglobulinemia (WM) patients. However, there are no published data regarding the prognostic value of these molecules in WM regarding progression-free and overall survival.

Methods: To evaluate the effect of these markers of bone remodeling on survival parameters, we prospectively evaluated serum cytokines and biological markers in 55 patients with symptomatic WM before they received any kind of treatment. Serum levels of CCL-3 and bone remodeling markers were also evaluated in asymptomatic WM and IgM monoclonal gammopathy of undetermined significance. Furthermore, we assessed bone marrow biopsy samples from newly diagnosed WM patients for CCL-3 and RANKL expression.

Results: High circulating sRANKL values predicted shorter median overall survival (46 months vs. not reached, P = .025). High serum levels of CCL-3 predicted shorter median progression-free survival (27 months vs. not reached, P = .048). At bone marrow biopsy evaluation, the whole number of the neoplastic cells revealed strong cytoplasmic positivity for CCL-3, while the neoplastic clone did not express RANKL.

Conclusion: We conclude that WM cells produce CCL-3 and possibly enhance the production of RANKL in the bone microenvironment. The correlation of sRANKL and CCL-3 with survival reveals the importance of these cytokines in disease biology and highlights the significance of the interactions between WM and stromal cells for the development of WM. Finally, these findings provide the rationale for the use of anti-RANKL and anti-CCL-3 drugs in animal models of WM before their clinical evaluation.