Background The study of the ability of monocytes to activate associated with the clinical activity of immunological markers of inflammation in systemic lupus erythematosus (SLE) will provide important and fundamentally new information on the involvement of these cells in the development of autoimmune rheumatic diseases.

Objectives To study macrophage activation in untreated systemic lupus erythematosus (SLE) patients (pts).

Methods A total of 21 active SLE pts (female/male 15/6) were enrolled in the study (median age was 35[24; 41] years; disease duration was 8 [2; 14] months; SLADAI-2K was 7 [6;16]). The control group consisted of 29 volunteers (23F/6M, median age 38 [35; 48] years).

Isolation of monocytes was carried out according to the standard procedure for obtaining a leukocyte fraction in a Ficoll gradient and subsequent selection of CD14 + cells using magnetic separation. After isolation, the cells were cultured in X-Vivo medium. To assess the degree of monocyte activation, cells were stimulated by the addition of LPS. The value of monocyte activation was expressed as a ratio of the level of secretion of proinflammatory cytokines by monocytes cultured with and without LPS addition. Secretion levels were determined by ELISA. The belonging of the isolated cells to CD14 + monocytes was additionally confirmed by flow cytometry.

Results Macrophage activation was 4.8 (2.8;7.3) in SLE pts and 10,2(3.5;11,6) in control group, p>0,05. In SLE pts macrophage activation was independent of age, sex, body mass index, traditional risk factors (arterial hypertension, overweight, smoking, family history of cardiovascular diseases), SLADAI-2K. No association was found between macrophage activation and levels of ANA, C3, C4, and anti-dsDNA.

Conclusions No differences in macrophage activation were found in SLE pts and control group. Macrophage activation was independent of age, sex, traditional risk factors, and SLE-related parameters.