Regulatory B cell imbalance correlates with Tfh expansion in systemic sclerosis

Objective. Systemic sclerosis (SSc) is an autoimmune disease with fibrosis, microangiopathy and immune dysfunction. B cell abnormalities characterised by autoantibody production and polyclonal B cell activation play an important role in the pathogenesis of SSc. We previously identified an expansion of functional and activated circulating T follicular helper (cTfh) cells in SSc patients. The aim of this study was to analyse the frequency of regulatory B (Breg) cell subsets and the correlation with Tfh in SSc patients. Methods. Circulating Breg cells CD24(hi)CD38(hi) and CD27(+)CD24(hi) levels and cTfh cells CD4(+)CXCR5(+)PD1(+) were determined by cytometry in 50 SSc patients and 32 healthy subjects. Results. The frequency of Breg cells CD24(hi)CD38(hi) and CD24(hi)CD27(+) was significantly reduced in patients with SSc as compared to controls (p=0.02 and p