C4A and Arthritis: Of the patients who fulfilled the EULAR/ ACR 2019 criteria but not the ACR 1997 criteria (37/57), the common manifestation in this cohort were fever (62%; n = 23), arthritis (49%; n = 18), nephritis (16%; n = 6) and proteinuria (14%; n = 5) while the most common immunological parameters included dsDNA (62%; n = 23), positive VDRL (49%; n = 18) and low complements (C3 and C4) (51%; n = 19) at first visit.