RESUMO
Objective: Systemic sclerosis is an autoimmune disease characterized by fibrosis of the skin and internal organs including the lung. Mucosal-associated invariant T cells are innate-like T lymphocytes able to produce various cytokines and cytotoxic mediators such as granzyme B. A large body of evidence supports a role of mucosal-associated invariant T cells in autoimmune disease but more recent reports suggest also a potential role in fibrotic conditions. Therefore, we herein addressed the question as whether mucosal-associated invariant T cells may have an altered profile in systemic sclerosis. Methods: Mucosal-associated invariant T cell frequency was analyzed by flow cytometry, using fresh peripheral blood from 74 consecutive systemic sclerosis patients who were compared to 44 healthy donors. In addition, in-depth mucosal-associated invariant T cell phenotype and function were analyzed in unselected 29 women with systemic sclerosis who were compared to 23 healthy women donors. Results: Proportion of circulating mucosal-associated invariant T cells was significantly reduced by 68% in systemic sclerosis compared to healthy donors (0.78% in systemic sclerosis vs 2.5%, p < 0.0001). Within systemic sclerosis subsets, mucosal-associated invariant T cells were reduced in patients with interstitial lung disease (systemic sclerosis-interstitial lung disease) (0.56% vs 0.96% in patients without interstitial lung disease, p = 0.04). Moreover, in systemic sclerosis patients, mucosal-associated invariant T cells displayed an activated phenotype indicated by markedly increased CD69+ mucosal-associated invariant T cell frequency (20% mucosal-associated invariant T cell CD69+ compared to 9.4% in healthy donors, p = 0.0014). Interestingly, mucosal-associated invariant T cells from systemic sclerosis-interstitial lung disease patients had a more pronounced altered phenotype compared to systemic sclerosis without interstitial lung disease with a correlation between mucosal-associated invariant T cells expressing CCR6+ and mucosal-associated invariant T cell frequency (r = 0.8, p = 0.006). Conclusion: Circulating mucosal-associated invariant T cells were reduced and exhibited an activated phenotype in systemic sclerosis patients. This peripheral mucosal-associated invariant T cell deficiency may be related to enhanced apoptosis and/or homing in inflamed tissue, particularly in systemic sclerosis-interstitial lung disease patients.
RESUMO
OBJECTIVE: US of salivary glands (SGUS) is a non-invasive tool that allows for diagnosing primary SS (pSS) or secondary SS (sSS). However, little is known about the prevalence of US findings of SS in other CTDs. The aim of this multi-centre observational study was to evaluate, in CTD patients with or without SS, the prevalence of abnormal SGUS findings and the possible association of the findings with clinical or biological phenotypes. METHODS: B-Mode SGUS was performed by one operator blinded to clinical data. Each SG was semi-quantitatively rated on a scale from 0 to 4 according to the Jousse-Joulin score; a score ≥2 was considered pathological. RESULTS: Data for 194 patients were analysed (pSS, n = 30; sSS, n = 39; other CTDs, n = 77; controls, n = 48). SGUS findings were abnormal in 80%, 67%, 25% and 2% of patients, respectively. Independent of the underlying disease, age and sex, abnormal SGUS findings were significantly associated with presence of anti-SSA antibodies (P < 0.001), pSS (P < 0.001) and sSS (P < 0.01). Among SS patients, abnormal SGUS findings were associated with the presence of hypergammaglobulinemia, anti-SSA antibodies, objective eye dryness and increased anti-nuclear antibody level, with no difference in EULAR SS Disease Activity Index. CONCLUSION: Abnormal SGUS findings were associated with anti-SSA antibody positivity independent of the underlying disease. In SS patients, abnormal findings were associated with immunologic features and mouth involvement. Among CTD patients, SGUS changes may be associated with a particular immune profile.
