PRTN3 and idiopathic pulmonary fibrosis: In another study of AAV-ILD patients (56 with MPA and 39 with GPA), NSIP was the most common detected ILD (61%), followed by UIP (48%), and OP (10.5%), with NSIP was mainly observed in patients with c-ANCA positivity, while UIP was mainly found in patients with p-ANCA (50).