Sex-based differences in clinical phenotype and damage accrual among patients with systemic lupus erythematosus in Saudi Arabia: a multicenter cross-sectional study.

OBJECTIVE

To evaluate sex-based differences in clinical phenotype, disease activity, and damage accrual among patients with systemic lupus erythematosus (SLE) in a multicenter Saudi setting.

METHODS

This multicenter cross-sectional study evaluated 370 patients with SLE. Demographic, clinical, immunological, laboratory, treatment, disease activity, and damage data were compared by sex. Disease activity was assessed using the Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2 K), and damage was evaluated using the SLICC/ACR Damage Index (SDI). Regression models assessed predictors of renal damage.

RESULTS

In total, 322 patients (87.0%) were female and 48 (13.0%) were male. Age, disease duration, age at diagnosis, and follow-up duration were comparable between sexes. Musculoskeletal involvement was more frequent among females, whereas renal involvement, renal biopsy, and antiphospholipid antibody positivity were more frequent among males. In addition, use of prednisolone, mycophenolate mofetil, cyclophosphamide, tacrolimus, rituximab, and belimumab was more frequent among males. SLEDAI-2 K activity categories and total SLEDAI-2 K scores did not differ significantly by sex. Overall damage prevalence was similar; however, renal damage was significantly more frequent among males. In adjusted analyses, male sex remained independently associated with renal damage.

CONCLUSIONS

Males showed a distinct phenotype characterized by greater renal involvement, antiphospholipid antibody positivity, renal damage, and more intensive treatment exposure, despite similar global disease activity and overall damage prevalence. These findings suggest that sex-based differences in SLE are more apparent in organ-specific phenotypes and damage patterns than in global disease activity.