MPO and rheumatoid arthritis: For the reason stated above in regard to radiopathological findings, similar to UIP/IPF, MPO-ANCA-positive ILD most commonly showed a UIP pattern and honeycombing as rheumatoid arthritis (RA)-ILD [9,17,36], whereas ILD in patients with systemic sclerosis and myositis is predominantly associated with a non-UIP pattern [9,17,37].