Predictors of damage accrual by organ domain in systemic lupus erythematosus

Objectives Organ damage in systemic lupus erythematosus (SLE) is assessed using the SLICC/ACR Damage Index (SDI), which quantifies damage in 12 organ systems but generally reports a total score. We examined whether the risk factors for overall organ damage accrual captured those associated with domain-specific damage accrual in patients with SLE. Methods Data from a 13-country longitudinal SLE cohort were collected between 2013 and 2020 using standard templates. SDI was used to assess overall and domain-specific organ damage. A series of multi-failure, multivariate models were performed to examine the risk factors associated with overall and domain-specific damage accrual. Results A total of 3,449 patients with a median of 2.8 (IQR: 1.1, 5.6) years of follow-up were studied. Twenty-one percent (n = 717) patients accrued damage in at least one domain during the study period (musculoskeletal, 6%; renal and ocular, 5% each, neuropsychiatric, 2.5%; <2%, other domains). Risk factors for damage accrual differed among domains. Older age, cumulative glucocorticoid dose, existing skin damage, and diabetes were strong predictors in multiple but discrete domains. Asian ethnicity conferred greater risk of ocular, musculoskeletal, and diabetic damage accrual but was protective against peripheral vascular damage accrual. Smoking was a significant risk factor for peripheral vascular and skin damage accrual, while male sex was associated with the malignancy domain. Conclusion Risk factors for individual organ system damage accrual were highly varied in patients with SLE. Not all factors associated with domain-specific damage accrual were captured by the risk factors analysed for overall organ damage accrual. Clinical Trial Registration ClinicalTrials.gov; NCT03138941