Vol 13, Issue 12, 2020 Online - 2455-3891 Print - 0974-2441 HOSPITAL-BASED CLINICAL STUDY ON PREVALENCE OF TPO ANTIBODIES IN ASSOCIATION TO AUTOIMMUNE THYROID DISEASES IN TERTIARY CARE HOSPITAL JASJOT SINGH 1 , PRANAV KUMAR PRABHAKAR 2 , NURAKANT NEUPANE 3 * 1 Department of Medical Laboratory, OSF HealthCare Saint Francis Medical Center, Peoria-IL-61614, USA. 2 Department of Medical Laboratory Science, Lovely Professional University, Phagwara, Punjab, India. 3 Dpartment of Genetics Lab, National Academy of Medical Sciences, Bir Hospital, Kathmandu - 44600, Nepal. Email: nurakantn@gmail.com Received: 23 August 2020, Revised and Accepted: 22 October 2020 ABSTRACT Objective: Autoimmune thyroid disease is one of the organs specific autoimmune disorders. The onset is much more common in women than in men. Worldwide, 2–4% of women and only 1% of men have affected and the rate increases with age. Thyroperoxidase (TPO) antibodies (Abs) level helps to diagnose autoimmune thyroid disease along with levels of thyroid stimulating hormone (TSH), Free Tri-iodotyrosine (Free T 3 ), and Free Thyroxin(Free T 4 ) and it helps in differentiation between subclinical and overt thyroidism. The core objective of clinical study was to evaluate prevalence of anti-TPO Abs in association to autoimmune thyroid disease in a tertiary care hospital – Punjab. Methods: A cross-sectional study of random patient (n=200 patients) at a tertiary care hospital, Mohall – Punjab was carried out. All the patients fall in the age group 12–89 years. The parameters, which were used for the diagnosis of autoimmune thyroid disease, were anti-TPO level, Free T3 level, and Free T4 level. The patients were divided in different group on the basis of their age, gender, and their clinical conditions. The level of TPO Abs, TSH, Free T3, and Free T4 was noted for each patient. Electrochemiluminescence immunoassay method was used for determination of TPO Abs and other thyroid parameters. After a period of 16 weeks, subjects from different groups had great difference in their anti-TPO values in the autoimmune thyroid disease. Results: TPO Abs positive is one of the most common associated with hypothyroidism which was 36.5%, among them 20.5% suffered from subclinical hypothyroidism, whereas other remaining suffered from clinical hypothyroidism, clinical hyperthyroidism, and other autoimmune disease. Conclusion: TPO Abs level helps to diagnose autoimmune thyroid disease, along with this the level of TSH, Free T 3 , and Free T 4 helps in differentiation between subclinical and overt thyroidism. Keywords: Autoimmune, Anti-thyroperoxidase, Subclinical thyroidism, Overt thyroidism, Thyroid stimulating hormones, Free T3, Free T4. INTRODUCTION The thyroid gland contains numerous follicles, which are composed of epithelial follicular cells and colloid, is an endocrine gland located in the neck region in front of the larynx and trachea [1]. It references in Western medicine first time in 1656, when it was thought that the main function of the thyroid gland was to lubricate the trachea [2]. The master gland, maintenance, and regulation of metabolic processes throughout the body and adverse effect on under and over production of hormones, synthesizes tri-iodotyrosine (T 3 ), tetra-iodotyrosine (T 4 ), and thyroid-stimulating hormones (TSH) and regulated by feedback inhibition mechanism of hypothalamus [3]. One of the major endocrine diseases is autoimmune thyroid disease (ATD) in which immune system produces antibodies (Abs) against body’s own thyroid cells, that is, thyrocytes and causes inflammation of the gland [4]. The autoimmune endocrinal disease is characterized by the presence of high titers of Abs such as thyroperoxidase Abs (TPO) and thyroglobulin Abs produced by our own body system. These Abs damage the thyrocytes and causes inflammation of the thyroid gland. The onset is much more common in women, 2–4% women and only 1% of men are affected and this rate increases with the age [5,6]. Hereditary factors due to genetic alteration and environmental and endogenous factors such as advancing age, smoking, iodine overconsumption, adverse effects of medication, and hormonal changes (females) are key factors of Autoimmune thyroid disease [7,8]. The most common Abs measured in serum sample are thyroglobulin and TPO Abs [9]. Due to more specificity in the diagnosis of ATD, anti-TPO Abs are preferred along with results of TSH, Free T 3 , and T 4 . Free T 3 measurements support the differential diagnosis of thyroid disorders which are needed to distinguish different forms of hyperthyroidism and to identify patients with T 3 thyrotoxicosis [10,11]. The determination of Free T 4 is helpful for monitoring thyrosuppressive therapy [12,13]. Moreover, TSH is a very sensitive and specific parameter for assessing thyroid function and is particularly suitable for early detection or exclusion of disorders in the central regulating circuit between the hypothalamus, pituitary, and thyroid [14-17]. The TSH level varies in hypothyroidism and hyperthyroidism. On the basis of laboratory results of anti-TPO Abs, TSH level, thyroid hormones level, we can differentiate between euthyroidism, subclinical thyroidism, and clinical or overt thyroidism. In case of euthyroidism, the level of anti-TPO Abs, TSH, Free T 3 , and Free T 4 remains normal. In subclinical thyroidism, the level of Anti-TPO Abs and TSH increases but Free T 3 and Free T 4 remains normal. This is asymptomatic and only mild impairment occurs in the thyroid gland. If it remains, untreated, it will switch over to clinical thyroidism. Subclinical thyroidism is much more common than overt thyroidism, so early diagnosis and treatment may prevent the onset of overt thyroidism and its associated effects [18]. Level of anti-TPO Abs, TSH markedly increases, and thyroid hormones will increase or decrease according to hyperthyroidism or hypothyroidism, respectively, in overt thyroidism. Overt or clinical thyroidism is symptomatic and it may cause further complications such as depression and unexplained © 2020 The Authors. Published by Innovare Academic Sciences Pvt Ltd. This is an open access article under the CC BY license (http://creativecommons. org/licenses/by/4. 0/) DOI: http://dx.doi.org/10.22159/ajpcr.2020.v13i12.39513 Research Article