Comparison of thrombocyte count, averagethrombocyte volume (MPV) and neutrophil/lymphocyte ratio in hyperthroid, euthyroid, and hypothyroid stages of subbacute thyroiditis

Subacute thyroiditis (SAT) usually develops following viral inflammation of the upper respiratory tract. It is also called granulomatous giant cell thyroiditis or De Quervain's thyroiditis. It presents with pain around the thyroid gland and in the entire neck. It is an inflammatory thyroid gland disease. As a result of the developing inflammatory condition, the thyroid gland is damaged and the thyroid hormones it contains are released into the bloodstream in high amounts. As a result of this high hormonal secretion, symptoms of thyrotoxicosis occur. As the characteristic course of the disease, the thyroid gland enters a recovery period with treatment or over time. As a result, the thyroid heals and its functions return to normal. It usually heals spontaneously within 8-10 months, but there are cases where recovery can take up to a year. It is also known that subacute thyroiditis can recur in some cases. Rarely, it can cause permanent damage and hypothyroidism. In addition to their metabolic and physiological functions, thyroid hormones are also effective in the differentiation and normal development of tissues. Mean platelet volume (MPV) indicates mean platelet size, platelet production rate, and stimulation. Platelet to lymphocyte ratio (PLR) and neutrophil to lymphocyte ratio (NLR) are known markers of systemic inflammatory response. Although NLR and MPV have been studied before in thyroiditis diseases, they have not been investigated in thyrotoxicosis, euthyroid, and hypothyroid stages of the same person in SAT patients. In our study, it was aimed to compare the platelet count, MPV and NLR ratio at each stage of the disease in SAT disease. 35 patients who applied with SAT between February 2018 and 2020 in Gaziosmanpaşa University Faculty of Medicine Endocrinology Clinic were followed up prospectively for 1 year. Laboratory parameters (TSH, ST4, hemogram, biochemistry) of the patients were recorded in three phases of the disease (euthyroid phase, hypothyroid phase and hyperthyroid phase). Parameters such as MPV, NLR values, PLR values and platelet values obtained at each stage of SAT disease were compared. In this study, the NLR rate of patients with SAT in the hyperthyroid stage (2.70±1.31); NLR rates in hypothyroid (1.98±1.02) and euthyroid (1.96±1.64) stages were found to be significantly higher (p<0.001). Likewise, hyperthyroid stage platelet 8 values of patients with SAT diagnosis (360.74±96.98 10/L); platelet values were found to be significantly higher in hypothyroid (259.81±67.1 10/L) and euthyroid (263.68±76.62 10/L) stages (p<0.001). There was no significant difference between MPV rates in all 3 stages of patients with SAT. As a result, NLR and platelet count parameters in the 3 stages of the disease of SAT patients were found to be statistically significantly higher in the hyperthyroid stage compared to the values in the euthyroid and hypothyroid stages. However, no significant difference was found in the MPV parameter measured in all three stages. Prospective studies with a larger number of patients are needed to use parameters such as platelet count, NLR, MPV in the diagnosis and follow-up of SAT. Keywords:Hypothyroidism, hyperthyroidism, mean platelet volume, neutrophil / lymphocyte ratio, platelet / lymphocyte ratio, platelet count