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Updated: Jun 30, 2026
Quantifying Myeloperoxidase-DNA and Neutrophil Elastase-DNA Complexes from Neutrophil Extracellular Traps by Using a Modified Sandwich ELISA
Published on: May 12, 2023
Testing on formalin-fixed neutrophils is less sensitive and specific for small vessel vasculitis, and less sensitive
Wendy Pollock1, Michelle Trevisin, Judy Savige
1Gribbles Pathology, Melbourne, VIC, Australia.
This study evaluated the usefulness of testing sera with perinuclear antineutrophil cytoplasmic antibodies (P-ANCA) on formalin-fixed neutrophils to differentiate between vasculitis and other diseases, and to distinguish between myeloperoxidase (MPO) and other antigen targets. Sera from active (n=24) or treated vasculitis (n=23) and non-vasculitic disease (n=37) were tested in 3 ethanol- and 2 formalin-fixed neutrophil assays, and in 12 MPO-ANCA ELISAs. The sensitivity of demonstrating that P-ANCA became cytoplasmic on formalin-fixed cells in vasculitis, and negative in non-vasculitic disease was 75-79% in different assays compared with 88% for positivity in the majority of MPO-ANCA ELISAs. The sensitivity and specificity of demonstrating that P-ANCA became cytoplasmic where the target was MPO, and disappeared with other antigens were 89% and 74-80% respectively in different assays. P-ANCA specificity for MPO should be confirmed in one of the better-performing MPO-ANCA ELISAs.
This study evaluated the usefulness of testing sera with perinuclear antineutrophil cytoplasmic antibodies (P-ANCA) on formalin-fixed neutrophils to differentiate between vasculitis and other diseases, and to distinguish between myeloperoxidase (MPO) and other antigen targets. Sera from active (n=24) or treated vasculitis (n=23) and non-vasculitic disease (n=37) were tested in 3 ethanol- and 2 formalin-fixed neutrophil assays, and in 12 MPO-ANCA ELISAs. The sensitivity of demonstrating that P-ANCA became cytoplasmic on formalin-fixed cells in vasculitis, and negative in non-vasculitic disease was 75-79% in different assays compared with 88% for positivity in the majority of MPO-ANCA ELISAs. The sensitivity and specificity of demonstrating that P-ANCA became cytoplasmic where the target was MPO, and disappeared with other antigens were 89% and 74-80% respectively in different assays. P-ANCA specificity for MPO should be confirmed in one of the better-performing MPO-ANCA ELISAs.
