FoxP3+ CXCR5+ CD4+ T cell frequencies are increased in peripheral blood of patients with primary Sjögren's syndrome.

We recently explored the expression of CXCR5 on T and B cells from peripheral blood of patients with primary Sjögren's syndrome (SS). Here we investigated the frequency of CD25+ FoxP3+ CD4+ regulatory T cells (Tregs ) among CXCR5+ CD4+ follicular cells in the same cohort of patients. We confirm that the frequency of Tregs among follicular T cells is increased in SS patients and also provide novel data showing an increased frequency of PD-1 expressing cells among CXCR5+ FoxP3+ CD4+ T cells.