The antinuclear antibody HEp-2 indirect immunofluorescence harmonization and competency assessment program of the Society for Clinical Microbiologists of Türkiye: analysis of 7-year assessment results.

Abstract

Introduction: Accurate and harmonized antinuclear antibody HEp-2 indirect immunofluorescence (IIF) reporting is essential for reliable communication between laboratories and clinicians. In Türkiye, a national online HEp-2 IIF competency assessment program has been operating since 2018, with 3 runs per year and participation of individual users representing clinical laboratories nationwide. The program evaluates the performance of participants and identifies training and reporting needs.

Methods: Between 2018 and 2025, 21 runs were conducted; the accuracy of competent-level and expert-level fluorescence pattern identification was analyzed. Twenty-six to 64 participants took part in each run. Since 2021, reflex test recommendations have been incorporated.

Results: The competent-level fluorescence patterns most accurately identified were AC-1, AC-3, AC-6/7, AC-8/9/10, AC-11/12, and AC-15/16/17, while AC-0 and AC-2/30 showed less than 80% accuracy in at least 1 run. Among expert-level patterns, accuracy was highest for pattern AC-27 and lowest for pattern AC-29, with low rates for AC-5, AC-6, AC-15, and AC-20. Reflex test recommendations were generally accurate (75.6%-100%).

Discussion: The results revealed good performance for many competent-level nuclear and cytoplasmic patterns and satisfactory reflex test recommendations. Persistent challenges were recognized, however, for patterns AC-29, AC-5, AC-20, and AC-0. Competency self-assessment, combined with collective performance evaluation, may provide insight for the harmonization of HEp-2 IIF reporting and improvement of laboratory-clinician collaboration.