CD38 and systemic sclerosis: After purification of CD19+ B cells, multiparametric flow cytometry was performed and the frequencies of CD19+IgD−CD27−CD38+ double negative (DN) 1, CD19+IgDloCD27+CD38+ unswitched, CD19+IgD−CD27+CD38+CD95− resting switched and CD19+IgD−CD27+CD38−CD95+ activated switched memory (ASM) B cells were determined, and correlated with clinical features of SSc.