Broadened autoantibody profiling in incomplete lupus erythematosus 2448

Description Incomplete lupus erythematosus (ILE) is characterized by clinical and/or serological features suggestive of systemic lupus erythematosus (SLE) but insufficient for disease classification. While some ILE patients progress to SLE, many maintain a mild disease course. The mechanisms underlying ILE remain unclear, complicating diagnosis and treatment. This study further characterized the autoantibody profiles of ILE patients compared to SLE patients within a racially diverse cohort. Using the ImmunArray iCHIP™ platform, serum autoantibody responses against 922 autoimmune antigens were assessed in ILE (n = 220), SLE (n = 42), and control (n = 35) samples. Overall, ILE patients exhibited higher prevalence of autoantibodies compared to controls, independent of ancestry. ILE autoantibody reactivities were distinct from those in SLE patients and varied by ancestry, with a higher prevalence of autoantibodies in ILE/SLE patients of African descent compared to those of European descent. Specifically, ILE patients of African descent had significantly higher IgM reactivity toward CD137, CD80, and HVEM, while those of European descent showed elevated IgG responses toward CD29, C4a, and MASP2 relative to SLE patients. These findings describe unique immunologic targets in ILE and correlates with potential disease progression. Personalized, ancestry-specific diagnostic strategies may improve patient management.