AL amyloidosis is a plasmacellular discrasia characterized by the deposition of light chains fibrils that infiltrate tissues leading to multisystemic organ involvement. Amyloidosis can be systemic or localized disease. No immunological markers are avaibable to distinguish the systemic from localized disease. IL-4 and IL-1 cytokines were performed to evaluate if there is a different inflammatory pattern between the two clinical forms. IL-4 is the central regulator of T helper 2 (Th2) immune responses, with also a major impact on innate immune cells. IL-1 is produced by macrophages, monocytes, fibroblasts and dendritic cells which play an important role in the inflammatory response, activating the Th1-mediated IL2 release. IL-1 increases the expression of adhesion factors on endothelial cells to enable transmigration of leukocytes to sites of infection. The study was devoted to evaluate serum levels of IL-4 and IL-1 in systemic or localized AL amyloidosis at presentation and to find out potential Th1 and Th2 disequilibrium. Blood samples were collected from 8 patients with systemic amyloidosis and from 4 patients with localized amyloidosis. Serum IL-4 and IL-1 levels were detected. Mann-Whitney test and correlation test were used to analyze results. IL-4 level was significantly (p < 0.05) higher in patients with localized disease compared to the group with systemic amyloidosis. IL-1 was instead significantly (p < 0.01) increased in systemic disease. In this, an inverse correlation between IL-4 and IL-1a was found (r2= –0.707; p = 0.05). In systemic amyloidosis, the regulatory mechanism of Th1/Th2 response was polarized versus Th1, as demonstrated by low serum level of IL-4 and high level of IL-1. The negative correlation between serum IL-4 and IL-1 levels demonstrates a disregulation of the immune system in systemic disease as supported by the increased activity of Th1. The results seem to hypothesize that IL-4 could be able to antagonize the diffusion of disease, as demonstrated by the higher IL-4 serum levels in localized amyloidosis. So IL-4 and IL-1 can be considered sensible markers for the inflammatory response assessment both in systemic and localized amyloidosis.
No relevant conflicts of interest to declare.
Asterisk with author names denotes non-ASH members.