GSTM1 and microscopic polyangiitis: In summary of the above results, the clinical parameters influencing AAV prognosis included age, pathological categories (MPA, GPA, and other types), serum ANCA types (negative or positive for MPO-ANCA and/or PR3-ANCA), ANCA IIF staining patterns (negative or positive for p-ANCA and/or c-ANCA), BVAS, Scr, GFR, NLR, RBC, Hb, lymphocyte, TP, albumin, A/G, UA, CRP, ESR, and C3.