Comparison of Three Classification Criteria Sets for Systemic Lupus Erythematosus: A Study Looking at Links to Outcome and Mortality

Objective To compare the ability of the American College of Rheumatology (ACR), Systemic Lupus International Collaborating Clinics (SLICC), and European League Against Rheumatism (EULAR)/ACR systemic lupus erythematosus (SLE) classification criteria sets to provide information regarding organ damage and mortality, over a 10-year follow-up period. Methods Using data from 100 patients, we completed each classification set at the time of diagnosis and recorded the SLICC/ACR Damage Index (SDI) score, renal damage, major cardiovascular events, and death, 10 years later. We reviewed the presence of other autoantibodies, linked to SLE but not included in the classification criteria sets, and assessed whether they impacted the predictive capacity of the classification sets. Results We found a statistically significant association between the EULAR/ACR set and renal damage and SDI score, the latter after adjustment for age and sex. In the patients negative for other autoantibodies, higher EULAR/ACR scores were associated with higher rates of organ damage. Conclusion These data suggest that the EULAR/ACR set may offer useful prognostic information, because higher scores were associated with higher rates of organ damage. These findings were clearer in patients negative for nondiagnostic SLE autoantibodies, who may benefit more from the predictive capacity of the EULAR/ACR set.