Stem cell mobilization and harvesting by leukapheresis alters systemic cytokine levels in patients with multiple myeloma

Abstract

Background aims: Stem cell mobilization and harvesting by peripheral blood leukapheresis in patients with myeloma can alter plasma levels of certain cytokines. In the present study, we investigated the effects of these interventions on a larger group of cytokines.

Methods: Plasma cytokine levels were determined in 15 patients with myeloma who were undergoing peripheral blood stem cell harvesting, and we compared the patients with healthy donors who were undergoing platelet apheresis.

Results: Several cytokines showed altered levels in patients with myeloma when examined after chemotherapy plus granulocyte colony-stimulating factor-induced stem cell mobilization. The most striking effect was increased levels of several CCL (CCL2/3/4) and CXCL (CXCL5/8/10/11) chemokines as well as increased thrombopoietin, interleukin 1 receptor antagonist, interleukin-4, granulocyte colony-stimulating factor and hepatocyte growth factor. Stem cell harvesting by apheresis altered the plasma levels of several mediators (CD40 ligand, interleukin 1 receptor antagonist, CCL5 and CXCL5/8/10/11). Apheresis in patients with myeloma had divergent effects on these chemokine levels, although they were all still significantly higher than for healthy individuals. Thrombapheresis in healthy individuals had only minor effects on plasma cytokine levels. Stem cell graft supernatants showed high levels of several cytokines, especially CCL and CXCL chemokines. Analyses of chemokine profiles in pre-apheresis plasma and graft supernatants suggested that such profiling can be used to detect prognostically relevant differences between patients.

Conclusions: Our results demonstrate that patients with myeloma have an altered cytokine network during stem cell mobilization, and the network is further altered during stem cell harvesting by leukapheresis. These treatment- or procedure-induced alterations involve several mediators known to affect myeloma cell proliferation, migration and survival.