Abstract:

Objective To investigate the role of multiplexed bead-based immunoassay in the determination of anti-neutrophil cytoplasmic antibody（ANCA）-associated vasculitis（AAV）. Methods A total of 300 patients with AAV,275 autoimmune disease patients without AAV and 277 healthy subjects（healthy control group） were enrolled. The roles of indirect immunofluorescence assay（IFA）,line immunoassay（LIA） and multiplexed bead-based immunoassay were evaluated by comparing the results of ANCA,anti-myeloperoxidase（MPO） antibody and anti-protease 3（PR3） antibody determinations. The optimal method for the determination of AAV was screened. Results There was no difference in the positive rate between LIA and multiplexed bead-based immunoassay by comparing the results of anti-MPO antibody and anti-PR3 antibody determinations. The positive rates were 83.1% and 78.2%,respectively,and the kappa value was >0.75. Multiplexed bead-based immunoassay showed higher sensitivity and specificity（85.7% and 82.6%） than those of LIA（59.7% and 56.6%）（P<0.05）. The models of cytoplasmic antineutrophil cytoplasmic antibody（cANCA）+PR3 and perinuclear antineutrophil cytoplasmic antibody（pANCA）+MPO showed higher positive rates in the diagnosis of AAV,and the positive rates were 42.4% and 45.0%,respectively. Conclusions Multiplexed bead-based immunoassay shows high sensitivity and specificity for ANCA determination,and the combined determination with IFA plays a role in the diagnosis of AAV.

Key words: Multiplexed bead-based immunoassay, Anti-neutrophil cytoplasmic antibody-associated vasculitis, Line immunoassay, Indirect immunofluorescence assay