Prevalence and Clinical Utility of TSH Receptor Antibody Positivity in Indian Hyperthyroid Subjects

We undertook a retrospective analysis of 52 subjects attending Karnataka institute of endocrinology and research, Bengaluru from March 2023 to August 2025. The study included subjects who had been diagnosed with hyperthyroidism and treated with anti-thyroid drugs. Informed consent was taken from all the participants. Hyperthyroidism was defined as a suppressed TSH (<0.27 mU/L) and elevated free thyroxine (fT4) (>22.0 pmol/L). Demographic data, initial thyroid hormone levels, thyroid antibody titres, doses of ATDs, follow-up thyroid hormone levels and clinical course were reviewed. Patients included in this study were treated using carbimazole with a dose-titration regimen. Patients were reviewed every 4-6 weeks during the first few months of treatment until thyroid hormone levels have stabilized. Results: TSH receptor antibody was positive in 80.8% of subjects studied. 55.8% of subjects were females. Family history of hyperthyroidism was present in only 2 subjects. Age of the subjects studied ranged from 18 to 80 years. Mean FT4 was 43.42 ± 25.82 and 29.06 ± 10.83 in TSH receptor antibody positive and negative subjects respectively. Mean TSH receptor antibody titres were 13.08 ± 13.47 and 0.83 ± 0.17 in TSH receptor antibody positive and negative subjects respectively. Anti TPO antibody was positive in 67.4% of the subjects studied. Conclusions: TSH receptor antibody was positive in 80.8% of subjects studied in our study. So the 80.8% of the subjects had Graves’ disease. The remaining 19.2% of subjects could be toxic multi nodular goitre, toxic adenoma, thyroiditis or TRAb negative Graves’ disease. Graves orbitopathy was present in 13.5% of the subjects and they were all positive for TSH receptor antibodies.