Fig. 1From: Elevated serum autoantibodies against co-inhibitory PD-1 facilitate T cell proliferation and correlate with disease activity in new-onset systemic lupus erythematosus patientsElevated levels of PD-1 antibodies (IgG isotype) in new-onset SLE patients. The serum levels of PD-1 autoantibodies IgG isotype (a) and IgM isotype (b) from SLE patients (◆, n = 90), pSS patients (▲, n = 50), RA patients (■, n = 50), AS patients (▼, n = 25) and healthy controls (HC, ●, n = 80). All standards and samples were run in technical replicates, and readings were performed in duplicates. The optical density (OD) value for each individual is represented as a single point. Values represent the means ± SD. **p < 0.01, ***p < 0.001. AS ankylosing spondylitis, Ig immunoglobulin, HC healthy control, PD-1 programmed cell death protein, SS Sjogren’s syndrome, RA rheumatoid arthritis, SLE systemic lupus erythematosus 1Back to article page