Risk factors for damage in childhood-onset systemic lupus erythematosus: cumulative disease activity and medication use predict disease damage.

Objective: The Systemic Lupus International Collaborating Clinics/American College of Rheumatology (SLICC/ACR) Damage Index measures damage in adult patients with systemic lupus erythematosus (SLE), but its usefulness in patients with childhood-onset SLE has not been examined. This study was conducted to evaluate the sensibility of the SLICC/ACR Damage Index, to investigate how cumulative disease activity is related to damage in childhood-onset SLE, and to identify other risk factors for damage in childhood-onset SLE.

Methods: Disease activity and damage in 66 patients with newly diagnosed childhood-onset SLE were assessed retrospectively, and information on potential risk factors for damage (age, race, sex, medications, duration of disease, hypertension, body mass index, antiphospholipid antibodies, kidney disease, acute thrombocytopenia) was obtained. In addition, a group of physicians was surveyed to establish the sensibility of the SLICC/ACR Damage Index in childhood-onset SLE.

Results: The SLICC/ACR Damage Index was found to have face, content, and construct validity when used in children. The mean SLICC/ACR Damage Index score of the patients was 1.76 (mean followup 3.3 years). Cumulative disease activity over time was the single best predictor of damage (R(2) = 0.30). Other, possibly important risk factors for damage were corticosteroid treatment, the presence of antiphospholipid antibodies, and acute thrombocytopenia. It was determined that immunosuppressive agents may be protective.

Conclusion: The SLICC/ACR Damage Index, though useful in childhood-onset SLE, may benefit from the introduction of weightings and redefinition of some of the items. Ongoing disease activity leads to disease damage, and treatment should be prompt. Prolonged use of high-dose corticosteroids may further increase damage, but use of immunosuppressive agents may protect against disease damage; this latter finding may have potential implications for the treatment of childhood-onset SLE and deserves further study. The relationship between disease activity and concomitant use of medication also requires further investigation.