Research Information System
Thesis Type: Expertise In Medicine
Institution Of The Thesis: Gazi University, Tıp Fakültesi, Turkey
Approval Date: 2018
Thesis Language: Turkish
Student: Dr. Meriç Coşkun
Supervisor: MEHMET AYHAN KARAKOÇ
Abstract:Hashimoto thyroiditis (HT) is autoimmune thyroid disease progressing with thyroid cell damage. The most common cause of hypothyroidism in developed countries having sufficient iodine intake is HT. It occurs in 10% of the general population. It's more common in females. The disease is usually diagnosed with elevated TSH low free T4 and high antibody levels. Although the genetic and environmental factors influence the pathogenesis of the disease, the mechanism is not fully understood. HT may be associated with other autoimmune diseases. The human cathelicidin (LL-37) is one of the most important members of the antimicrobial and immunostimulator family of peptides. It is synthesized as a proprotein called hCAMP 18 from the gene domain on the chromosome. LL-37 has antimicrobial and immunomodulatory effects on different pathways. The role of LL-37 in the immunomodulator role in autoimmune diseases, vasculitis and other inflammatory diseases has been researched. There is no literature on the role of LL-37 in HT The study was carried out between January- April 2018 in the Department of Endocrinology and Metabolism Diseases of Gazi University Medical Faculty Hospital on HT patients. In this study, it was aimed to determine serum LL-37 level in patients with HT. Age, BMI, TSH, T3, T4, Anti TPO, Anti Tg, 25 (OH)D3 levels were recorded in HT and healthy controls. Blood samples were collected from the cases and serum LL-37 levels were measured by ELISA method. Forty healthy controls and 48 patients with HT were included in the study. There is no difference between the groups in terms of age, sex, and BMI LL-37 was found to be significantly higher in HT with autoimmune thyroid disease (p< 0,001). In patients with HT, no significant correlation was found between serum LL-37 level and sex, age, disease age, TSH, free T3, free T4 level, levothyroxine sodium doxia, anti TG titre, anti TPO titre, 25(OH)D3 level. LL-37 was found to be diagnostic value for prediction of HT (p <0.001). The positive predictive value was 73.9% and the negative predictive value was 66.7% in HT according to the 714pg / ml limit value determined by 71% sensitivity and 70% specificity for LL-37 , respectively. It was also found that LL-37 was diagnostic value in anti TG negative cases (p = 0.001) ( Positive Predictive Value 67%, Negative Predictive Value 70%, when diagnosed according to 714pg / ml limit value determined by 68% sensitivity and 70% specificity ). The incidence of HT was 73.9% in cases with a LL-37 value greater than 714 pg / mL. In a patient with a LL-37 value greater than 714 pg / ml, HT is thought to be about 5.6 times more likely. (OR = 5.66, p< 0.001) The use of LL-37 as a diagnostic marker for HT is limited by the increased incidence of infectious or autoimmune inflammatory processes. Therefore, when LL-37 alone is used, it is appropriate to use it in combination with anti-TPO which has high specificity for HT. In addition, since it is not affected by disease age, autoantibody levels and other parameters, autoantibody is thought to be a diagnostic marker in autoimmune thyroid diseases group and there is a need for further studies in groups including bigger and different autoimmune thyroid diseases.