Background/Purpose: We have shown that disease course over time in systemic lupus erythematosus (SLE) follows three distinct patterns (prolonged remission, relapsing remitting and persistently active). The impact of these patterns on the development of specific co-morbidities, such as atherosclerotic vascular events (AVEs), osteoporosis and osteonecrosis is not known. The aim of the present study was to assess the incidence of such co-morbidities in lupus patients in the long term.

Methods: The inception patients of our long-term longitudinal cohort (enrolled within 18 months of diagnosis), with at least 10 years of follow-up and no time interval >18 months between consecutive visits, were investigated. Prolonged remission (PR) was defined as a clinical SLEDAI-2K=0 [serology (anti-dsDNA antibodies and C3/C4 levels) excluded], achieved within five years since enrolment and maintained for ≥10 years after that. Relapsing-remitting (RR) pattern was defined based on ≥2 remission periods (one remission period equals two consecutive visits with a clinical SLEDAI-2K=0), while patients with no remission were categorized as persistently active (PA). Incidence rates for AVEs (angina, myocardial infarction, re-vascularization procedure, transient ischemic attack, stroke, peripheral vascular disease), osteoporosis (according to the WHO definition) and osteonecrosis (confirmed radiologically) were calculated at 10 years and at the end of follow-up (median 17.5 years).

Results: Of 267 patients who fulfilled the inclusion criteria, 27 (10.1%) achieved PR, 180 (67.4%) were RR and 25 (9.4%) PA. At enrollment, there were no significant differences in demographic, clinical, immunological and therapeutic characteristics among the groups. At 10 years, PA patients had received significantly more glucocorticosteroids [39.4±24.3g vs. 16.6±10.7g and 27.3±18.4g for the PR and RR groups, p<0.001]. The incidence rates of AVEs, osteoporosis and osteonecrosis at 10 years and for the entire duration of follow up are given in Table 1.

Conclusion: Disease course had a significant impact on the rates of atherosclerotic vascular events, osteoporosis and osteonecrosis over time. Patients who had achieved prolonged remission developed significantly fewer such co-morbidities whereas the differences between the RR and PA patients were not statistically significant.