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 (T(regs) ) among CXCR5(+) CD4(+) follicular cells in the same cohort of patients. We confirm that the frequency of T(regs) 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.