Pro-inflammatory activation of monocytes in patients with immunoinflammatory rheumatic diseases

The pathogenesis of immunoinflammatory rheumatic diseases (IRDs) is based on chronic inflammation, one of the key mechanisms of which may be abnormal activation of macrophages, leading to further disruption of the immune system.The aim – to evaluate the pro-inflammatory activation of circulating monocytes in patients with IRDs.Material and methods. The study included 149 participants: 53 patients with rheumatoid arthritis (RA), 45 – with systemic lupus erythematosus (SLE), 34 – with systemic scleroderma (SSc) and 17 participants without IRD, aged 30 to 65 years. Basal and lipolysaccharide (LPS)-stimulated secretion of monocytes was studied in a primary culture of monocytes obtained by immunomagnetic separation from blood. Quantitative assessment of the cytokines tumor necrosis factor-α (TNF-α), interleukin 1β (IL-1β) and the monocyte chemoattractant protein-1 (MCP-1) was carried out in the culture fluid by ELISA. Pro-inflammatory activation of monocytes was calculated as the ratio of LPS-stimulated and basal secretions.Results. It was shown that the basal secretion of all studied cytokines was significantly increased in all groups of patients with IRDs, except for the secretion of IL-1β in the SLE group, compared with the control. LPS-stimulated secretion of TNF-α was increased and MCP-1 was decreased in patients with IRDs compared to the control group; LPS-stimulated IL-1β secretion only in the SSc group was significantly different from the control group. In the RA group, monocyte activation was reduced for all cytokines compared to the control, in the SLE group – for TNF-α and MCP-1, in the SSc group – for MCP-1.Conclusion. The decrease in pro-inflammatory activation of monocytes in patients with IRDs is due to a high level of basal secretion of cytokines, which can lead to disruption of the adequate immune response in these diseases and is an important link in the pathogenesis of chronic inflammation.