Comparative study between two European inception cohorts of patients with early systemic lupus erythematosus.

Objectives: To compare the main characteristics of two inception cohorts (Italian [ITC] and Spanish [SPC]) cohorts of patients with systemic lupus erythematosus (SLE) at the time of diagnosis and at one year of follow-up.

Methods: Demographic, clinical and immunological characteristics, and treatments at SLE diagnosis and at 12 months of follow-up of ITC and SPC were compared.

Results: One hundred and sixty-four patients in the ITC and 231 patients in the SPC were compared. the patients from ITC were younger at SLE diagnosis (41.1±15.0 years vs. 46.4±15.6 years; p<0.001) and had a higher prevalence of arthritis (62.8% vs. 45.5%; p=0.001), serositis (25.6% vs. 16.0%; p=0.026), neurological involvement (7.9% vs. 1.7%; p=0.006), and immunological abnormalities (anti-dsDNA, anti-Sm, antiphospholipid antibodies) (93.9% vs. 77.8%; p<0.001). Conversely, photosensitivity (29.5% in ITC vs. 45.9% in SPC; p=0.001) and oral ulcers (12.4% vs. 30.3%; p<0.001) were more frequent at onset of SLE in the Spanish patients. At the first 12 months of follow-up, these differences were maintained. At SLE onset, more Italian patients received glucocorticoids (85.4% vs. 50.2%; p<0.001) and immunosuppressive agents. At 12 months of follow-up, more Spanish patients were treated with antimalarials (75.6% in ITC vs. 90.0% in SPC; p<0.001). Conversely, the use of glucocorticoids was lower in SPC (89.0% in ITC vs. 57.1% in SPC; p<0.001).

Conclusions: These cohorts presented different profiles in terms of pattern of organ/system involvement and disease treatment, possibly as a consequence of patient selection or different disease management approaches between Italy and Spain.