Using antineutrophil cytoplasmic antibody testing to diagnose vasculitis: can test-ordering guidelines improve diagnostic accuracy?

Arch Intern Med. 2002 Jul 8;162(13):1509-14. doi: 10.1001/archinte.162.13.1509.


Background: Antineutrophil cytoplasmic antibodies (ANCAs) are strongly associated with Wegener granulomatosis, Churg-Strauss angiitis, microscopic polyangiitis, and pauci-immune glomerulonephritis, referred to collectively as ANCA-associated vasculitis (AAVs). It is unclear how accurate ANCA measurement is for diagnosing AAV in diverse populations or whether proposed ANCA test-ordering guidelines improve test performance.

Methods: We assembled a retrospective case series of hospitalized and ambulatory patients from 2 academic medical centers to assess the diagnostic accuracy of ANCA measurement by enzyme-linked immunosorbent assay in identifying cases of AAV. In addition, we assessed the effect of applying proposed ANCA test-ordering guidelines on test performance.

Results: For ANCA testing, sensitivity was 81%; specificity, 98%; positive predictive value, 54%; and negative predictive value, 99%. There were no significant changes in operating characteristics after applying the guideline criteria. Using guidelines would have decreased ANCA test ordering by 23% and would have decreased the false-positive rate by 27%. No cases of AAV would have been missed if only patients fulfilling the guidelines were ANCA tested.

Conclusion: A positive result on an enzyme-linked immunosorbent assay ANCA test, as it is currently ordered, is not a definitive diagnostic indicator of AAV. Compliance with guidelines for ANCA testing would decrease the number of false-positive results and has the potential to reduce total test expenditures.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Antibodies, Antineutrophil Cytoplasmic / blood*
  • Diagnosis, Differential
  • Enzyme-Linked Immunosorbent Assay
  • Female
  • Humans
  • Male
  • Medical Records
  • Middle Aged
  • Practice Guidelines as Topic
  • Predictive Value of Tests
  • Reproducibility of Results
  • Retrospective Studies
  • Sensitivity and Specificity
  • Vasculitis / diagnosis*
  • Vasculitis / immunology


  • Antibodies, Antineutrophil Cytoplasmic