Alessandra Penatti

BACKGROUND: T-cell subsets, immune cells and their cytokine profiles in blood and synovial compartments in rheumatoid arthritis (RA) and inflammatory osteoarthritis (OA) to define specific immune signatures. METHODS: T-cell subset frequencies were determined by flow cytometry, and cytokine concentrations in serum and SF were measured by ELISA. RESULTS: In peripheral blood, OA patients had altered frequencies of regulatory T-cell subsets, and higher frequencies of Th17 and of Th1/17 cells than RA patients. In the synovial compartment of OA patients, conventional Th17 cells were largely excluded, while Th1/17 cells were enriched and more frequent than in RA patients. Conversely, in the synovial compartment of RA patients, regulatory T cells and Tfh cells were enriched and more frequent then in OA patients. IL-17 and Blys were increased both in serum and SF of RA patients, and correlated with autoantibodies and disease activity. Notably, Blys levels were already significantly elevated in RA patients with low disease activity score in 28 joints (DAS28) and without autoantibody positivity. CONCLUSIONS: Although patients with inflammatory OA have immune activation in the synovial compartment, they display different T-cell subset frequencies and cytokine profiles. Soluble mediators such as Blys might help to discriminate mild clinical forms of RA from inflammatory OA particularly at the onset of the disease.

OBJECTIVE: To evaluate the 12-year survival of the first tumor necrosis factor inhibitor (TNFi) treatment in a cohort of rheumatoid arthritis (RA) patients, comparing the between-groups discontinuation rates for infliximab, etanercept, and adalimumab. METHODS: RA patients treated with their first TNFi were investigated from a local registry. Before and after adjusting for propensity scores, overall and by individual TNFi 12-year drug retention was evaluated. Drug survival rates were calculated using the Kaplan-Meier method and compared by the Cox extended model. Subanalyses were performed according to concomitant methotrexate (MTX) and discontinuation reasons. RESULTS: Of 583 patients, 222 were treated with infliximab, 179 with etanercept, and 182 with adalimumab; 33.7% and 26% discontinued the first TNFi because of inefficacy or adverse events, respectively. The overall 12-year drug survival rate for the unmatched population was 23.4%. In the propensity score-adjusted population, the hazard ratio (HR) for treatment discontinuation was significantly greater for adalimumab and infliximab versus etanercept (HR 2.89 [95% confidence interval (95% CI) 2.2-3.78] and HR 2.56 [95% CI 1.92-3.4], respectively), and no difference was found between and for adalimumab versus infliximab (HR 1.16 [95% CI 0.91-1.47]). The incidence of withdrawal due to secondary inefficacy was stable from 3 to 12 years for etanercept, but progressively increased for the monoclonal antibodies. Concomitant MTX significantly increased the survival of both adalimumab and etanercept (HR 1.48 [95% CI 1.18-1.86]). CONCLUSION: The overall 12-year drug survival rate was 23.4%, being significantly higher for etanercept than adalimumab and infliximab. Etanercept discontinuations for inefficacy did not increase from 3 to 12 years. Concomitant MTX increased adalimumab and etanercept drug survival.

Interleukin 10 (IL-10) is an antiinflammatory cytokine, but also promotes B cell responses and plays a pathogenic role in systemic lupus erythematosus (SLE). CD4 + CCR6 + IL-7R + T cells from human tonsils produced IL-10 following stimulation by naïve B cells, which promoted B cell immunoglobulin G (IgG) production. These tonsillar CCR6 + B helper T cells were phenotypically distinct from follicular helper T (T FH ) cells and lacked BCL6 expression. In peripheral blood, a CCR6 + T cell population with similar characteristics was identified, which lacked Th17- and T FH -associated gene signatures and differentiation-associated surface markers. CD4 + CCR6 + T cells expressing IL-10, but not IL-17, were also detectable in the spleens of cytokine reporter mice. They provided help for IgG production in vivo, and expanded systemically in pristane-induced lupus-like disease. In SLE patients, CD4 + CCR6 + IL-7R + T cells were associated with the presence of pathogenic anti-dsDNA (double-stranded DNA) antibodies, and provided spontaneous help for autoantibody production ex vivo. Strikingly, IL-10–producing CCR6 + T cells were highly abundant in lymph nodes of SLE patients, and colocalized with B cells at the margins of follicles. In conclusion, we identified a previously uncharacterized population of extrafollicular B helper T cells, which produced IL-10 and could play a prominent pathogenic role in SLE.