Totally, 100 ANCA positive untreated patients were investigated for anti-id testing, which included 22 patients of RLV (BVAS 8-12), 20 cases of MPA (BVAS 17-30), 20 cases of WG (BVAS 20-30), 20 cases of ICGN (BVAS 15-20), and 18 cases of Class IV LN (SLEDAI 10-30). Here, ID1 is linked to microscopic polyangiitis.