Objective To explore the clinical.significance of serum anti-lysosomal associated membrane protein-2 (LAMP-2) antibody in the pathogenesis of anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AASV) by investigating the relationship of its levels and AASV.Methods Sera from twenty patients with AASV and twenty healthy controls were collected.Serum anti-LAMP-2 antibody was detected using commercial enzyme linked immunosorbent assay (ELISA) kits.Anti-LAMP-2 antibody levels between the two groups were assessed using the t test,the correlation between anti-LAMP-2 antibody levels and erythrocyte sedimentation rate (ESR),C-reactive protein (CRP) was assessed by Spearman's rank correlation test,the correlation between anti-LAMP-2 antibody levels and the Birmingham vasculitis activity score(BVAS),hemoglobin (Hb),albumin (Alb) was assessed by Pearson's rank correlation test.Results ① The serum level of anti-LAMP-2 antibody in patients with AASV [(3714±1446) pg/ml] was higher than that in the healthy controls [(174±43) pg/ml] (t=10.94,P＜0.05).The serum level of Hb [(99±30) g/L] and Alb [(27±5) g/L]in patients with AASV was lower than that in healthy controls [(138±14) g/L,(44±3) g/L] (t=5.27,t=13.04,P＞0.05).② The level of anti-LAMP-2 antibody in AASV was positively correlated with BVAS (r=0.669 9,P＜0.05),and was not found elevated compared with ESR,CRP,Hb and Alb (P＞0.05).Conclusion ① AntiLAMP-2 antibody is involved in the pathogenesis of AASV.② Anti-LAMP-2 antibody is correlated with the activity of AASV,it may be an indicator of AASV disease activity.