Jolly Anil John, Aneesh Basheer, Dhandapani Govindarajan, Manjiri Phansalkar, Nayyar Iqbal
BACKGROUND Hashimoto’s thyroiditis is the most common cause of hypothyroidism in Iodine sufficient areas. Diagnosis depends on histopathological or cytological features. The accuracy of autoantibodies among hypothyroid patients for diagnosis of Hashimoto’s thyroiditis was explored in this study. MATERIALS AND METHODS A cross sectional study was conducted on persons with laboratory confirmed hypothyroidism at a tertiary care hospital. All subjects underwent determination of anti-thyroid peroxidase antibodies (anti-TPO) and Fine Needle Aspiration Cytology (FNAC) of the thyroid. The sensitivity and specificity of anti-TPO antibodies was determined using FNAC as gold standard. RESULTS Fatigue was the most common symptom among the hypothyroid patients. The diagnostic sensitivity and specificity of anti-TPO antibodies was 88.37% and 50% respectively for Hashimoto’s thyroiditis. Using this sensitivity and specificity, the calculated positive likelihood ratio (LR) is 1.80 and negative likelihood ratio is 0.23. CONCLUSION Anti-TPO appears to be a relatively sensitive test for diagnosis of Hashimoto’s thyroiditis among patients with hypothyroidism; however, its specificity is low. The low negative likelihood ratio transforms it into an effective test to rule out Hashimoto’s thyroiditis in populations with low pre-test probability of Hashimoto’s thyroiditis.
