Assessment of the correlation between circRNA expression and AS-related clinical findings
To assess whether the six RT-qPCR-validated DECs (hsa_circ_0000702, hsa_circ_0006209, hsa_circ_0047920, hsa_circ_0001543, hsa_circ_0072697, hsa_circ_0005076) could be relevant biomarkers of AS disease, we conducted a series of ROC curve and correlational analyses. The expression of hsa_circ_0006209 and hsa_circ_0047920 was detected to be positively correlated with AS patient CRP levels (Fig. 5A and 5B), while hsa_circ_0072697 levels were negatively correlated with ESR and BASDAI levels in these patients (Fig. 5C and 5D). ROC curve analyses indicated that all six DECs were able to effectively differentiate between AS and control PBMC samples, and hsa_circ_0072697 exhibited the highest area under the curve value (AUC: 0.9867; 95% confidence interval [CI]: 0.9552-1.018;P <0:0001). Therefore, hsa_circ_0072697 may be a particularly promising diagnostic biomarker for AS (Fig. 6, Table 4).