遅発性全身性エリテマトーデスの二面性の解明：横断研究

Systemic lupus erythematosus (SLE) is a complex, heterogeneous autoimmune disease whose presentation can vary widely with patient age. While SLE in young adults has been extensively characterized, less is known about phenotypes of late-onset SLE.

This study aimed to characterize the features of late-onset SLE patients in a Chinese cross-sectional study. Patients diagnosed with SLE at age 50 years or older were classified as having late-onset SLE. Early-onset SLE patients from the same cohort were included as controls. Demographic, clinical, and laboratory data were collected, and a two-step cluster analysis was employed to categorize late-onset SLE patients.

A total of 141 patients (27.48%) were classified as late-onset SLE. The onset of lupus in late-onset patients is more insidious, they exhibited lower systemic lupus erythematosus disease activity index-2000 (SLEDAI-2K) scores, and had significantly fewer instances of fever, mucocutaneous, and positive of antibodies compared to early-onset SLE (all P values < 0.05). However, late-onset SLE patients had a higher prevalence of comorbidities, particularly Sjögren's syndrome (P < 0.001). Additionally, late-onset SLE was associated with a high frequency of interstitial lung disease (ILD) and thrombotic events (P < 0.001, P < 0.001; respectively). Two distinct clusters of late-onset SLE patients were identified. Cluster 1 was characterized by the presence of SLE-specific autoantibodies such as anti-double stranded DNA (anti-dsDNA), anti-Smith (anti-Sm) with higher SLEDAI-2K scores (11.8 ± 5.2). In contrast, cluster 2 presented with a high frequency of anti-Sjögren syndrome antigen A (anti-SSA) antibodies and Sjögren's syndrome with a significantly lower SLEDAI-2K scores (8.8 ± 5.4) at diagnosis.

This study refines our understanding of late-onset SLE by delineating two subgroups and suggests that age-stratified approaches to diagnosis and management may improve patient care.