Table 1

Likelihood ratios (with 95% CIs) for the cut-off point proposed by the manufacturer and for a combination of tests are given

Embedded Image

  • The number of patients and controls with a particular test result or combination of test result are given as well. The highest level of reactivity from the PR3-ANCA and MPO-ANCA determinations was selected for analysis. Data are from ref. 2.

  • The AUC of the Inova QuantaFlash PR3-ANCA and MPO-ANCA assay for AAV was 0.925 (95% CI 0.909 to 0.940). The AUC of combining QuantaFlash with an IIF ANCA assay was 0.94 (95% CI 0.925 to 0.953), which was not significantly different from the AUC of performing only QuantaFlash (p=0.088) (method of Hanley and McNeil, MedCalc). The AUC of combining QuantaFlash with an immunoassay for MPO- and PR3-ANCA from Euroimmun on all samples was 0.943 (95% CI 0.928 to 0.955), which was significantly different from the AUC of QuantaFlash alone (p=0.01) (method of Hanley and McNeil, MedCalc).

  • AAV, ANCA-associated vasculitides; ANCA, antineutrophil cytoplasmic antibodies; MPO, myeloperoxidase.