Regional variation in serum ficolin levels and their association with disease activity and clinical manifestations in systemic lupus erythematosus (SLE) patients from India.

The lectin pathway, activated by ficolins, contributes to systemic lupus erythematosus (SLE) pathogenesis, but ficolin data remain inconsistent across populations. Present muti-centric cross-sectional study assessed serum ficolin-1, -2, and - 3 levels and their associations with clinical features and disease activity among SLE patients from five Indian regions (Mumbai, Assam, Meghalaya, Manipur, and Nagaland). Serum levels of ficolin-1, ficolin-2, and ficolin-3 were measured using ELISA. Disease activity was assessed using the SELENA-SLEDAI score. Statistical analyses were performed using non-parametric tests, with p < 0.05 considered significant. Serum ficolin levels differed significantly by region. Ficolin-1 and ficolin-2 levels were positively correlated with the renal involvement in SLE patients from Mumbai (r = 0.218; p < 0.001 and r = 0.199; p = 0.001, respectively), while ficolin-1 levels were also correlated with lupus nephritis (LN) in SLE patients from Manipur (r = 0.247; p = 0.040). In Assam, ficolin-2 levels were significantly reduced in patients with mucocutaneous manifestations (r=-0.258; p = 0.014), and ficolin-3 levels showed a negative correlation with musculoskeletal manifestations (r=-0.217; p = 0.040). In Mumbai, ficolin-1 levels were positively associated with disease activity (r = 0.139; p = 0.018), and ficolin-3 levels correlated positively with anti-dsDNA autoantibodies (r = 0.172; p = 0.004). Conversely, ficolin-3 levels showed a negative correlation with anti-dsDNA (r=-0.470; p < 0.001) in Assam. The present study demonstrated significant regional variations in ficolin levels among SLE patients across India. Association of ficolin-1 and ficolin-3 with specific organ involvement suggested their potential as possible immunological indicators in SLE. These findings suggested the importance of considering regional and ethnic differences in SLE management and warranted further validation through larger, longitudinal studies.