PRTN3 and idiopathic pulmonary fibrosis: Compared with the group with low ACPA proportions (n = 29), the IPF group with high ACPA proportions (n = 15) in the BALF was younger (65.2 ± 9.4 years vs. 70.9 ± 6.8 years, p = 0.03) and had more females (6 out of 15 (40%) vs. 2 out of 29 (7%), p = 0.01).