To clarify the frequency and outcome of patients with systemic lupus erythematosus (SLE) who achieved the clinical state as serologically active clinically quiescent (SACQ) and to identify factors associated with the flare of disease.
Clinical data of patients diagnosed as SLE and followed in Peking University First Hospital from 2009 to 2015 were retrospectively reviewed. Six hundred eighty-two patients who were followed up for more than 6 months were analyzed. SACQ was defined as an at least a 6-month period with persistent serologic activity and without clinical activity and daily dose of prednisone or equivalent were less than 7.5 mg. Serologically quiescent clinically quiescent (SQCQ) patients served as control groups. Data including demographics, initial symptoms, duration to SACQ, treatments before and after SACQ, and characteristics of the patients suffered from flare were analyzed.
Among the 682 patients, 170 patients were SACQ (24.9%) and 187 patients were SQCQ. SQCQ patients (38.61 ± 15.08 years old) were older at baseline than SACQ patients (38.61 ± 15.08 years vs. 32.09 ± 14.35 years, p < 0.001). Of 170 SACQ patients, 32.9% experienced flare that was significantly higher than 15.5% of SQCQ patients (29/187). Corticosteroids (OR 1.323, 95% CI 1.129 to 1.550; p = 0.001) was an independent risk factor for flare, while antimalarials (OR 0.045, 95% CI 0.004 to 0.474; p = 0.010) and immunosuppressants (OR 0.332, 95% CI 0.156 to 0.706; p = 0.004) were protective factors in SACQ patients; however, only antimalarials was protective factors in SQCQ patients (OR 0.028, 95% CI 0.001 to 0.743; p = 0.033).
About one third of SLE patients with SACQ experience flare, significantly more frequent than that of patients with SQCQ. Thus, approach to prevent flare in SACQ patient is required. Maintenance therapy of hydroxychloroquine and immunosuppressant agents may be protective and beneficial treatment strategy in these patients.