PRTN3 and interstitial lung disease: Meanwhile, RF titer (WMD = 183.62 (IU/mL), 95% CI: 66.94–300.30; P = 0.002) and ACPA titer (WMD = 194.18 (IU/mL), 95% CI: 115.89–272.47; P < 0.00001) were significantly associated with increased risk of RA-ILD.