Efficiency of automated microscopy to interpret anti-nuclear antibodies in a routine laboratory by indirect immunofluorescence assay

Abstract

Background: The detection of anti-nuclear antibody (ANA) by indirect immunofluorescence (IIF) assay is the gold standard for ANA screening in systemic autoimmune diseases. The interpretation of ANA results by human visual experts, however, is a time-consuming procedure. Recently, computer-aided automated immunofluorescence microscopy (EURO Pattern Suite) system has been used as a standard procedure in many clinical laboratories worldwide.

Objective: To compare the performance of IIF assay-based ANA detection using the automated EURO Pattern Suite with visual expert inspection.

Methods: A total of 5,000 clinical samples were collected and analyzed for ANA using the EURO Pattern Suite automated system from June to December 2021. The positive and negative results, staining patterns, and endpoint titers were compared between EURO Pattern Suite and visual readings.

Results: The sensitivity, specificity, and overall concordance of the EURO Pattern Suite were 78.4%, 97.0%, and 91.4%, respectively. The concordance between the ANA titer measurement at the same titer level generated by the automated analyzer and human specialists was 85.1% while the endpoint titers within ±1 titer difference were 96.7%. On the other hand, the concordances of pattern recognition of single and mixed patterns were 66.9% and 71.5%, respectively.

Conclusion: Despite the automated EURO Pattern Suite system’s remarkably decent performance, we nonetheless recommend that the output created by the automated system be visually inspected by human specialists to ensure a high-quality standard.