PANORAMA DA PESQUISA DE ANTICORPOS ANTICITOPLASMA DE NEUTRÓFILO (ANCA)

Abstract

The identification of antineutrophil cytoplasmic antibodies (ANCA) in the late 20th century revolutionized vasculitis diagnostics, with indirect immunofluorescence (IIF) protocols standardized since the 1988 workshop and the advent of ELISA assays for PR3-ANCA and MPO-ANCA. This study aimed to assess, following the 2017 Bossuyt et al. consensus, the current performance and remaining gaps of ANCA detection methods. An integrative review was conducted in PubMed (January 2017–search date), including clinical trials, systematic reviews, meta-analyses, and guidelines in English or Portuguese, yielding 27 records and 10 final inclusions. Antigen-specific immunoassays demonstrated sensitivity and specificity equivalent or superior to IIF for granulomatosis with polyangiitis and microscopic polyangiitis, yet lacked objective criteria for “high-quality” assay designation. Pre-analytical variability in neutrophil fixation protocols and inter-platform discrepancies were also noted. Emerging technologies — automated IIF reading, multiplex ELISAs, NET-based flow cytometry, and certified reference materials — show promise to reduce subjectivity and harmonize results but require large-scale prospective validation. We conclude that reliable ANCA testing demands rigorous local validation, protocol standardization, use of certified calibrators, and ongoing international consensus updates to maintain clinical efficacy.