EVALUATION OF VISUAL MULTIPARAMETRIC INDIRECT IMMUNOFLUORESCENCE FOR THE DETECTION OF AUTOANTIBODIES
- Boris Gilburd, Israel
Abstract
Background and Aims
Detection of autoantibodies is based on a two-step algorithm that includes indirect immunofluorescence (IIF) on HEp2 cells and subsequent confirmation of disease specific autoantibodies by a solid phase-based immunoassay (singleplex or multiplex). Simultaneous cell- and microbead-based autoantibodies detection by automated or visual indirect immunofluorescence (IIF) may be a specific and cost-effective alternative approach for the evaluation of SARDs.
Methods
Sera of 29 patients with SARDs and 56 patients without SARDs were assessed by HEp2 ANA IIF test (INOVA, NOVAView) and a subsequent (Bio-Rad, BioPlex 2200 ANA) assay for the presence of ANA-specific autoantibodies, respectively. The samples were also analyzed by a visual multiplex IIF test (CytoBead ANA 2 test) for the simultaneous evaluation of ANA pattern on HEp-2 cells and diseases-specific autoantibodies (anti-dsDNA, anti-Scl-70, anti-SS-A/Ro60, anti-SS-A/Ro52, anti-SS-B/La, anti-Jo-1, anti-CENP-B, anti-Sm, and anti-nRNP). For the validation of ANA/DFS IIF, anti-DFS70 positive sera samples were evaluated by DFS70 CIA using BIO-FLASH instrument.
Results
A good correlation was found between visual CytoBead ANA 2 test and automated ANA IIF (kappa=0.633). A very good agreement was found between CytoBead ANA 2 test and BioPlex 2200 ANA Screen with regard to specific autoantibodies (kappa>0.8 for every autoantibody), expect for anti-RNP antibodies (kappa = 0.660). All anti-DFS70 positive sera samples evaluated by ANA/ DFS IIF were also found to be positive by DFS70 CIA (kappa=1).
Conclusions
Based on these results, visual multiplex IIF using CytoBead ANA 2 test demonstrated a high diagnostic performance for detection of ANA and ANA-specific autoantibodies that was similar to the diagnostic performance of both screening and confirmation assays.