Monophasic Disease Course in Systemic Lupus Erythematosus

Disease course in systemic lupus erythematosus (SLE) is primarily relapsing-remitting. Long quiescent and chronically active patterns are less frequent. We recently described an atypical "monophasic" course in a small number of patients. The aim of the present study was to assess the prevalence and characteristics of such patients in a defined SLE cohort.

The inception patients of the University of Toronto Lupus Clinic (enrolled within 18 mos of diagnosis) were investigated. No time interval > 18 months was allowed between consecutive visits. A monophasic course was defined as Systemic Lupus Erythematosus Disease Activity Index 2000 = 0 (serology excluded), achieved within 5 years since enrollment and maintained for ≥ 10 years. Descriptive statistics were used.

Of 267 inception patients, 27 (10.1%) achieved prolonged clinical remission (≥ 10 yrs) and 20 (7.5%) sustained remission for the entire followup (18 yrs on average). Twelve patients were receiving no maintenance treatment 10 years after achieving remission. Clinical manifestations at diagnosis (apart from skin and musculoskeletal involvement) included 25% in each of central nervous system involvement and lupus nephritis (LN). Half the patients were serologically active. Ten years after achieving remission, two-thirds of the patients had discontinued glucocorticosteroids; the remaining were treated with 5 mg/day on average. Seven patients relapsed after 10 years, 4 with arthritis, 2 LN, and 1 catastrophic antiphospholipid syndrome.

A monophasic disease course was observed in 7.5% in this inception cohort. Patients sustained remission for 18 years on average, eventually without medications. Further study of such patients may provide unique pathophysiologic insights for SLE.