165 Identification of serum biomarkers for systemic lupus erythematosus using a library of phage displayed random peptides and deep sequencing

Abstract

Background Systemic lupus erythematosus (SLE) is a chronic, complex autoimmune disorder characterized by the production of autoantibodies and heterogeneous clinical presentation. Biomarkers are in urgent need for the accurate diagnosis of the disease. Methods SLE serum autoantibodies were discovered and validated using serum samples from independent sample cohorts encompassing 306 participants divided into three groups, i.e., healthy, SLE patients, and other autoimmune diseases. To discover biomarkers for SLE, a phage displayed random peptide library (Ph.D. 12) and deep sequencing were applied to screen specific autoantibodies in a total of 100 serum samples from 50 SLE patients and 50 healthy controls. A statistical analysis protocol was setup for the identification of peptides as potential biomarkers. For validation, ten peptides were analyzed using enzyme linked immunosorbent assays (ELISA) in two independent cohorts. Results For the screening phase, a total of 116 peptides were highly enriched by the sera of SLE patients as compared to that of the health controls. Further validation showed that using a set of four peptides panel could achieve an AUC of 0.86. Among the four peptides, two of them were further confirmed in an independent group of patients with SLE and other autoimmune diseases. Conclusions We demonstrate that a M13 phage displayed random peptide library in combination with deep sequencing can be used to identify peptides that could be specifically recognized by IgG in the sera of SLE patients. Funding Source(s): N/A