Under the treat-to-target strategy of the new century, to explore the characteristics of organ damage and its influencing in Chinese patients with systemic lupus erythematosus (SLE).

Consecutive patients diagnosed with SLE according to the 2012 Systemic Lupus International Collaborating Clinics (SLICC)or the 2019 American College of Rheumatology/ European League Against Rheumatism (ACR/EULAR) classification criteria were recruited from the First Affiliated Hospital of Xi'an Jiaotong University between 2017 and 2019. Eligible participants were aged 18-70 years, and demonstrated good compliance (≥3 visits annually). In this longitudinal cohort study, we assessed the attainment of lupus low disease activity state (LLDAS) and SLICC/ACR Damage Index (SDI) at each patient visit. Factors associated with the progression of organ damage were analyzed through intergroup comparisons. Cox regression analysis and Kaplan-Meier analyses were employed to evaluate risk factors for accrual of organ damage.

Among 364 enrolled patients, the prevalence of organ damage increased from 14.8% at baseline to 35.1% over a mean follow-up of 59.6±16.3 months. The most frequently affected system was musculoskeletal (15.9%), with bone infarction being particularly common (12.4%). Factors associated with increasing in SDI included older age, sustained non-LLDAS status, renal involvement and use of cyclophosphamide. In contrast, hydroxychloroquine use was associated with a lower risk of new organ damage. Kaplan-Meier analysis showed that failure to maintain LLDAS for over six months significantly higher increased the risk of damage progression. Multivariable analyses identified older age, male gender, pulmonary and mucocutaneous system activity, cyclophosphamide use and cumulative time spent in non-LLDAS as the primary risk factors for SDI increase, while hydroxychloroquine use served as a protective factor.

The pattern of organ damage in Chinese SLE patients is different from other ethnic groups. Musculoskeletal manifestations, especially osteonecrosis is the most frequent. Failure to sustain LLDAS is a key modifiable driver of organ damage. Notably, even six months of uncontrolled disease activity may lead to irreversible damage accrual.