AL amyloidosis is a pathology characterised by the deposition of fibrillary aggregates of immunoglobuline light chains with β-sheet conformation. The light chains are synthetized by neoplastic plasma cell and fibrils deposition can infiltrate tissues leading to multi systemic organ damage. To evaluate if vascular modifications are involved in AL amyloidosis, inflammatory activity of cytokines as MCP-1 and VEGF was investigated. MCP-1 is a chemokine that activates mononuclear phagocytes by promoting leukocyte-endothelium binding and migration to sites of inflammation, while VEGF is an endothelial cell mitogen and permeability factor that is potently angiogenic in bone marrow of AL amyloidosis patients. Aim of this study is to evaluate serum cytokines MCP-1 and VEGF levels in patients with systemic or localized AL amyloidosis at presentation to find out potential differences useful to define a characteristic inflammatory pattern. Blood samples were collected from 8 patients with systemic amyloidosis and from 4 patients with localized amyloidosis and analyzed for serum MCP-1 and VEGF levels. Mann-Whitney test and Spearman correlation were used to compare results. MCP-1 level was significantly higher in the serum of patients with systemic disease (350.52±58.70 pg/ml) compared to the group of patients with localized amyloidosis (147.82±26.03; p=0.004); VEGF was also significantly increased in systemic disease group (p= 0.028). In addition, a positive correlation between MCP-1 and VEGF (r2= 0.755; p=0.031) has been found in the group of patients with systemic amyloidosis. Results seems to suggest a difference in serum cytokine MCP-1 and VEGF levels between AL systemic and localized amyloidosis. In systemic amyloidosis the neoplastic plasma cells interact with bone marrow microenvironment resulting in VEGF release leading to a new angiogenesis also supported by an inflammatory cells increase. The MCP-1 activates and promotes leukocyte-endothelium binding increasing the inflammatory process. The high correlation between MCP-1 and VEGF suggests a positive relationship between a new angiogenesis and a migration of inflammatory cells in the bone marrow stroma. On the basis of our results, MCP-1 and VEGF chemokines can be used to evaluate the inflammatory process in patient with systemic or localized AL amyloidosis.
No relevant conflicts of interest to declare.
Asterisk with author names denotes non-ASH members.