Serum IL-6 and IL-21 are associated with markers of B cell activation and structural progression in early rheumatoid arthritis: results from the ESPOIR cohort
Department of Rheumatology, EA 4438, Strasbourg University Hospital, H?pital Hautepierre, 1 Avenue Molière, 67000 Strasbourg, France. jacques-eric.gottenberg@chru-strasbourg.fr