No abstract

No abstract

Disclosure of potential conflicts of interest: M. Arock has patents through CNRS (Centre national de la recherche scientifique) and ENS (Ecole normale sup erieure de Cachan) Cachan for human mast cell lines, preparations, and uses (WO 2013064639 A1). U. Raap has received research support and payment for lectures from Novartis Pharma. K. Hartmann has consultant arrangements with Novartis; has received payment for lectures from Abbvie, Biogen, and Novartis; and has received a research grant from Novartis. The rest of the authors declare that they have no relevant conflicts of interest. Almeida J, et al. Prognosis in adult indolent systemic mastocytosis: a long-term study of the Spanish Network on Mastocytosis in a series of 145 patients.

BackgroundThe aim was to investigate CD4+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.MethodsPeripheral blood, synovial fluid (SF) and synovial membranes (SM) of RA and OA patients were analyzed. CD4+T-cell subset frequencies were determined by flow cytometry, and cytokine concentrations in serum and SF were measured by ELISA.ResultsIn 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.ConclusionsAlthough 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.Electronic supplementary materialThe online version of this article (doi:10.1186/s13075-017-1305-1) contains supplementary material, which is available to authorized users.