〔Abstract〕 Objective To investigate the clinical application value of chemokine ligand(CCL)21 and its receptor chemokine(CCR)7 in patients with anti-neutrophil cytoplasmic antibody associated vasculitis.Methods The serum levels of CCL21 and its receptor CCR7 were measured by ELISA methods in 102 patients with AASV and 70healthy controls.At the same time,the correlation among the CCL21,CCR7,MPO,PR3 and general laboratory index of TNF-α,IL-6,BUN,CRE,C3,C4 ESR,CRP,BVAS in AASV patients was analyzed.Results The serum levels of the CCL21 and CCR7 were significantly higher in AASV patients than that in healthy controls [(276.95±57.34) vs(179.91±19.45);(85.85±18.77) vs(54.83±18.18) pg/ml](P<0.05).The serum levels of the CCL21 and CCR7 in MPO positive patients were higher than those in MPO negative patients [(294.94±58.15) vs(244.35±46.76);(90.64±18.38) vs(78.37±13.44) pg/ml](P<0.05).Moreover,The levels of the CCL21 and CCR7 were similar to those of TNF-α,IL-6,CRE,BUN,CRP,BVAS and MPO in AASV patients,the levels of the CCL21 and CCR7 in AASV patients were positively correlated.The serum levels of the CCL21 and CCR7 were found to be predictive of AASV activity with ROC.Conclusion The serum level of CCL21 and CCR7in AASV patients increased significantly,especially in MPO positive patients,and related to patients with renal function index and related inflammation index.Serum CCL21 and CCR7 are the influencing factors of BVAS in AASV patients,and have important significance in the diagnosis and judgment of AASV disease.