Serum PGLYRP‑1 is a highly discriminatory biomarker for the diagnosis of rheumatoid arthritis

Peptidoglycan recognition protein‑1 (PGLYRP‑1) is a part of the innate immune system. It is well‑known that dysregulation of innate immune responses is present in patients with rheumatoid arthritis (RA). However, the role of Pglyrp1/PGLYPR‑1 in RA is poorly understood. Reverse transcription‑quantitative polymerase chain reaction was used to detect the level of Pglyrp1 in peripheral blood mononuclear cells. An ELISA was used to measure the level of PGLYPR‑1 in the serum, and correlation analysis was performed to analyze the association between the level of PGLYPR‑1 in the serum and clinical characteristics. A receiver operating characteristic (ROC) curve was constructed to evaluate the diagnostic value of PGLYPR‑1 in serum. The expression of PGLYPR‑1 in the serum of healthy controls compared with PGLYPR‑1 in the serum from patients with RA was significantly increased compared with patients with systemic lupus erythematosus (SLE). The level of PGLYPR‑1 in serum was correlated with rheumatoid factor and anti‑cyclic citrullinated peptide. ROC curve analysis suggested that PGLYPR‑1 in the serum may have significant value for RA diagnosis. In addition, the risk score based on PGLYPR‑1 in the serum also significantly discriminated the patients with RA from the disease controls (SLE). The present study suggested that increased expression of PGLYPR‑1 in the serum from patients with RA may serve as a potential biomarker for RA diagnosis.