Flare, Persistently Active Disease, and Serologically Active Clinically Quiescent Disease in Systemic Lupus Erythematosus: A 2-Year Follow-Up Study

OBJECTIVE Several indices have been proposed to assess disease activity in patients with Systemic Lupus Erythematosus (SLE). Recent studies have showed a prevalence of flare between 28-35.3%, persistently active disease (PAD) between 46%-52% and serologically active clinically quiescent (SACQ) disease ranging from 6 to 15%. Our goal was to evaluate the flare, PAD and SACQ rate incidence in a cohort of SLE patients over a 2-year follow-up. METHODS We evaluated 394 SLE patients. Flare was defined as an increase in SLEDAI-2K score of ≥4 from the previous visit; PAD was defined as a SLEDAI-2K score of ≥4, on >2 consecutive visits; SACQ was defined as at least a 2-year period without clinical activity and with persistent serologic activity. RESULTS Among the 95 patients eligible for the analysis in 2009, 7 (7.3%) had ≥1 flare episode, whereas 9 (9.4%) had PAD. Similarly, among the 118 patients selected for the analysis in 2010, 6 (5%) had ≥1 flare episode, whereas 16 (13.5%) had PAD. Only 1/45 patient (2.2%) showed SACQ during the follow-up. CONCLUSION We showed a low incidence of flare, PAD and SACQ in Italian SLE patients compared with previous studies which could be partly explained by ethnic differences.