Figure 3.

circPTPN22 expression as a potential biomarker for RA diagnosis. (A) Venn diagram showing the overlap of 21 significantly differentially expressed circRNAs in RA and SLE compared with HCs. There were 128 significantly dysregulated circRNAs in PBMCs of SLE patients vs. HCs (blue area) and 71 significantly dysregulated circRNAs in PBMCs of RA patients vs. HCs (purple area). (B) The expression levels of circPTPN22 in PBMCs of 42 RA patients, 45 SLE patients and 44 HC were determined by reverse transcription-quantitative PCR. ROC curve analysis of the sensitivity and specificity of (C) circPTPN22 in RA patients and HCs, (D) circPTPN22 in PBMCs of RA patients and SLE and (E) circPTPN22 in PBMCs of SLE patients and HCs. **P<0.01, ***P<0.001. circRNA, circular RNA; RA, rheumatoid arthritis; SLE, systemic lupus erythematosus; HC, healthy controls; ROC, receiver operating characteristic; PBMCs, peripheral blood mononuclear cells; AUC, area under the curve.