MPO-ANCA was found in 70% of patients, and relapse disease was found in 9%. PLEX was used to treat around 30% of both MPO- ANCA and PR3-ANCA patients. Patients with PR3-ANCA (72%) had considerably higher ear, nose, and throat involvement than those with MPO-ANCA (37%) (p<0.001). RPGN was found in 61% of MPO-ANCA patients and 51% of PR3-ANCA patients, respectively. This evidence concerns the gene MPO and rapidly progressive glomerulonephritis.