Dutch single center study of ANCA tests (n 5518) betw 2012-2023; 286 (5.2%) were positive: 63% did not have AAV. ANCA+ Non-AAV pts had other CTD, neoplasia, infxn, or used specific drugs. IIF and ELISA 1st test - good negative predictive values. Performing a second test increased https://t.co/0oAhOg10VL