Akademik Veri Yönetim Sistemi
Bratislava Medical Journal, 2026 (SCI-Expanded, Scopus)
Background: Autoantibody testing is widely used in the evaluation of autoimmune diseases. However, interpretation of serological results may be influenced by demographic factors such as age and sex. Large-scale real-world studies assessing the relationship between demographic characteristics and autoantibody positivity remain limited. Methods: This retrospective descriptive study included adult patients (≥ 18 years) referred to the indirect immunofluorescence assay (IFA) laboratory of a tertiary care hospital between 2021 and 2023 with suspected autoimmune or inflammatory diseases. Only the first test result per patient was analyzed. A total of 23,515 patients with complete demographic data were included. Autoantibodies evaluated were antinuclear antibodies (ANA), anti-double-stranded DNA (anti-dsDNA), antimitochondrial antibodies (AMA), anti-smooth muscle antibodies (ASMA), perinuclear antineutrophil cytoplasmic antibodies (p-ANCA), and cytoplasmic ANCA (c-ANCA). All assays were performed using standardized indirect immunofluorescence methods. Statistical analyses were conducted using chi-square, Fisher’s exact, and linear-by-linear association tests. Results: Among 23,515 patients, 17,117 (72.8%) were female and 6,398 (27.2%) were male, with a mean age of 43.6 years. The number of evaluable positive/negative results was ANA (n = 16,534), anti-dsDNA (n = 3,765), p-ANCA (n = 850), c-ANCA (n = 833), AMA (n = 820), and ASMA (n = 713). Borderline/equivocal results were recorded separately and were not considered positive. In the revised tables, negative, borderline, and positive categories are presented consistently for each autoantibody parameter.Overall autoantibody positivity was higher in females than in males. ANA and anti-dsDNA positivity were significantly associated with sex (p < 0.05). ANA positivity demonstrated a significant increasing trend across age groups (p < 0.05). AMA positivity was significantly associated with both sex and age, showing a marked increase with advancing age (p < 0.05). In addition, p-ANCA positivity was significantly associated with sex (p = 0.011). Conclusion: Autoantibody positivity patterns detected by indirect immunofluorescence in a large tertiary care cohort were significantly influenced by age and sex. Higher positivity rates were observed in female patients, and age-related increases were particularly evident for ANA and AMA. These findings highlight the importance of considering demographic characteristics when interpreting autoantibody test results in clinical practice.