The evaluation of demographic and laboratory analysis of patients witch subacute thyroiditis

Introduction: Subacute thyroiditis which is an inflammatory disease of thyroid, is a rare cause of hyperthyroidism or thyrotoxicosis. The disease is more prevalent among women population and shows seasonal association. Subacute thyroiditis is characterized by neck pain and/or tenderness and fluctuation in thyroid functions during disease course. In this study, the patients with subacute thyroiditis in outpatient clinic of Endocrinology department in Dicle University Faculty of Medicine were analysed retrospectively. It is aimed to reevaluate for new diagnostic clues in subacute thyroiditis. Materials and Methods: Fifty patients (36 female, 14 male) with subacute thyroiditis and fifty one cases (37 female, 14 male) without any thyroid disease as a control group were included in this study. All patients were selected from time period of 2010-2014 in Endocrinology Clinic of Dicle University Faculty of Medicine. Demographic informations (age, gender, city of born, time of diagnosis and season), comorbidities, levels of free T4, free T3, TSH, thyroid otoantibody, thyroglobulin, sedimentation rate, CRP, CBC, ALT, AST, Ferritin and thyroid ultrasound and sintigraphy were evaluated retrospectively. The patient group and control groups were compared according to these parameters. Results: The mean age was found 39,94±12,2 in patients with subacute thyroiditis; 37,4±13,44 in control group. In patient group, female to male ratio was found 2,6/1. Evaluation for seasonal distribution showed that the diagnosis was made in 42% of cases in autumn, in 26% of cases in spring, in 20% of cases in summer, in 12% of cases in winter. It was found that sedimentation rate in patient group was significantly higher than in control group (53.7±14.22, 11.02±6.96; p<0.01), In patient group, leukocyte and neutrophil counts, neutrophil to lymphocyte ratio, T4 to T3 ratio were significantly high, but no valuable difference was found in lymphocyte count in both groups. However, mean platelet volume (MPV) and platelet distribution width (PDW) was lower in patient group rather than in control group (p<0.01). Analysis for thyroid otoantibody levels showed that anti-thyroglobulin positivity was seen more common in patient group (46.5% , 11.8%, p<0.01)), in contrast, no significant difference was found for anti-thyroid peroxidase positivity in both groups (p>0.05). Conclusion: In a patient presented with sore throat and high sedimentation rate in spring, subacute thyroiditis should be considered in differential diagnosis and thyroid function tests should be ordered. It was found that anti-TG antibody levels can be high, but anti-TPO antibody levels are low in subacute thyroiditis. Positivite anti-Tg antibody titer should not exclude the diagnosis. In differential diagnosis, anti-TPO antibody level is more valuable than anti-Tg antibody for autoimmune thyroid disorders. It was seen that T4 to T3 ratio and neutrophil to lymphocyte ratio are increased, but MPV is significanly decreased in subacute thyroiditis patients. Further studies are needed including the clinical use of these parameters. Keywords: subacute thyroiditis, seasonal association, sedimentation, anti-Tg, MPV