Prevalence of Anti-Thyroid Peroxidase Antibodies in Patients with Thyroid Disorders

Background Autoimmune thyroid disorders (AITDs) are among the most common organ-specific autoimmune diseases and represent a major cause of thyroid dysfunction worldwide. Their prevalence has been increasing in both developed and developing countries, with a higher occurrence among females. Anti-thyroid peroxidase (anti-TPO) antibodies are widely recognized as important biomarkers for the diagnosis and assessment of autoimmune thyroid diseases. Objective This study aimed to evaluate the prevalence of thyroid hormone dysfunction and determine the frequency of anti-TPO antibody positivity in individuals with thyroid-related disorders, as well as to assess the association between anti-TPO titers and thyroid hormone parameters. Methods A prospective cross-sectional observational study was conducted between February 2025 and September 2025 in the Department of Biochemistry, Department of Laboratory Medicine, AMCH. A total of 162 individuals with suspected thyroid disorders were included. Serum levels of thyroid-stimulating hormone (TSH), free triiodothyronine (fT3), free thyroxine (fT4), and anti-TPO antibodies were measured using chemiluminescence immunoassay (CLIA) on the Siemens ADVIA Centaur® XP platform. Statistical analysis was performed to evaluate associations between anti-TPO titers, thyroid hormone levels, age, and sex. Results Among the 162 participants, 54.3% were aged 20–39 years. Females constituted 86.4% of the study population, while males accounted for 13.6%. Hypothyroidism was identified in 47.5% of individuals and hyperthyroidism in 21.6%. Positive anti-TPO antibody titers were detected in 50% of the participants, with females representing 96% of positive cases. Anti-TPO titers showed significant associations with serum TSH (p = 0.009), serum fT3 (p = 0.037), and sex (p < 0.001). No significant association was observed with serum fT4 (p = 0.071) or age (p = 0.582). Conclusion Hypothyroidism was the most prevalent thyroid disorder, particularly among individuals aged 20–39 years, and showed a marked female predominance. The significant association between anti-TPO antibodies and thyroid hormone parameters highlights the clinical importance of anti-TPO evaluation in diagnosing and monitoring autoimmune thyroid disorders.