NOVEL DIAGNOSTIC BIOMARKER OF SYSTEMIC LUPUS ERYTHEMATOSUS: ANTICHAPERONIN CONTAINING T-COMPLEX POLYPEPTIDE 1 ANTIBODY

PV037 / #22 Poster Topic: AS04 - Biomarkers Background/Purpose Systemic lupus erythematosus (SLE) is diagnosed with several clinical and immunological criteria. To find a diagnostic biomarker of SLE, microarray technique was used to find SLE-specific autoantibodies and to provide a clear diagnosis. Methods Autoantibodies were discovered by analyzing sera of SLE patients and normal controls (NCs) using a human proteome microarray containing 21,000 purified proteins. This analysis revealed the presence of 63 SLE-specific autoantibodies. Notably, the antichaperonin containing t-complex polypeptide 1 (TCP1) antibody exhibited higher expression in patients with SLE. To validate the specificity of anti-TCP1 antibody expression in SLE, Dot blot analysis and enzyme-linked immunosorbent assay (ELISA) were conducted using sera from patients with SLE, NCs, and patients with rheumatoid arthritis, Behçet’s disease, and systemic sclerosis. Results Dot blot analysis was conducted using sera from patients with SLE and NCs, as well as patients with rheumatoid arthritis, Behçet’s disease, and systemic sclerosis. The results confirmed the detection of anti-TCP1 antibody in 79 out of 100 patients with SLE, with significantly elevated expression compared to both NCs and patients with other autoimmune diseases. We performed enzyme-linked immunosorbent assay (ELISA) to determine the relative amounts of anti-TCP1 antibody. ELISA analysis revealed markedly elevated anti-TCP1 antibody levels in the sera of patients with SLE (50.1 ± 17.3 AU, n=251) compared to those of NCs (33.9 ± 9.3 AU, n=50), RA (35 ± 8.7 AU, n=25), BD (37.5 ± 11.6 AU, n=28), and SSc (43 ± 11.9 AU, n=30). Conclusions These data suggest that anti-TCP1 antibody is a potential diagnostic biomarker of SLE.