Sex hormones seem to play an important role as modulators of the autoimmune disease onset/perpetuation. Generally, steroid hormones are implicated in the immune response, with estrogens as enhancers at least of the humoral immunity and androgens and progesterone (and glucocorticoids) as natural immunosuppressors. Synovial fluid levels (SF) of proinflammatory estrogens relative to androgens are significantly elevated in both male and female rheumatoid arthritis (RA) patients, as compared to controls, which is most probably due to increase of local enzymatic aromatase activity. Serum levels of estrogens have been found altered in RA patients, particularly estradiol in man. Thus, available steroid prehormones are rapidly converted to proinflammatory estrogens in the synovial tissue in the presence of inflammatory cytokines (i.e., TNFalpha, IL-1, IL-6). The increased estrogen concentrations observed in RA SF of both sexes are characterized mainly by the hydroxylated forms, in particular, 16alpha-hydroxyestrone, showing a mitogenic tumor growth stimulating role. Altered serum hydroxylated estrogens have been found also in serum of systemic lupus erythematosus (SLE) patients. As a matter of fact, our recent studies indicate that 17-beta estradiol (E2) clearly enhanced the expression of markers of cell growth and proliferation, whereas testosterone (T) induced an increase of markers indicating DNA damage and apoptosis. In particular, our data further shows that the enhancing role of estrogens on immune/inflammatory response is exerted by activating the NFkB complex pathway. In conclusion, locally increased estrogens (i.e., synovial tissue in RA or skin in SLE) might exert activating effects on cell proliferation, including macrophages and fibroblasts, suggesting new roles for estrogens in autoimmunity.
BackgroundSystemic sclerosis (SSc) is a disorder characterized by immune system alterations, vasculopathy and fibrosis. SSc-related interstitial lung disease (ILD) represents a common and early complication, being the leading cause of mortality.Monocytes/macrophages seem to have a key role in SSc-related ILD. Interestingly, the classically (M1) and alternatively (M2) activated monocyte/macrophage phenotype categorization is currently under revision.Our aim was to evaluate if circulating monocyte/macrophage phenotype could be used as biomarker for lung involvement in SSc. To this purpose we developed a wide phenotype characterization of circulating monocyte/macrophage subsets in SSc patients and we evaluated possible relations with lung involvement parameter values.MethodsA single centre cross-sectional study was performed in fifty-five consecutive SSc patients, during the year 2017. All clinical and instrumental tests requested for SSc follow up and in particular, lung computed tomography (CT) scan, pulmonary function tests (PFTs), Doppler echocardiography with systolic pulmonary artery pressure (sPAP) measurement, blood pro-hormone of brain natriuretic peptide (pro-BNP) evaluation, were performed in each patient in a maximum one-month period. Flow cytometry characterization of circulating cells belonging to the monocyte/macrophage lineage was performed using specific M1 (CD80, CD86, TLR2 and TLR4) and M2 surface markers (CD204, CD163 and CD206). Non-parametric tests were used for statistical analysis.ResultsA higher percentage of circulating CD204+CD163+CD206+TLR4+CD80+CD86+ and CD14+CD206+CD163+CD204+TLR4+CD80+CD86+ mixed M1/M2 monocyte/macrophage subsets, was identified to characterize patients affected by SSc-related ILD and higher systolic pulmonary artery pressure. Mixed M1/M2 monocyte/macrophage subset showed higher percentages in patients positive for anti-topoisomerase antibody, a known lung involvement predictor.ConclusionsThe present study shows for the first time, through a wide flow cytometry surface marker analysis, that higher circulating mixed M1/M2 monocyte/macrophage cell percentages are associated with ILD, sPAP and anti-topoisomerase antibody positivity in SSc, opening the path for research on their possible role as pathogenic or biomarker elements for SSc lung involvement.Electronic supplementary materialThe online version of this article (10.1186/s12931-018-0891-z) contains supplementary material, which is available to authorized users.
Different cytokine and steroidal hormone patterns suggest that patients with PMR and those with EORA/PMR seem to be have a more intensive inflammatory reaction and are more efficient responders to glucocorticoid treatment than patients with EORA.
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