Cell-free dna methylation evaluation in patients with thyroid diseases

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ANNALS OF CLINICAL AND ANALYTICAL MEDICINE, no.12, pp.1349-1353, 2022 (ESCI) identifier


Aim: The main aim of the study was to evaluate the DNA 5-methylcytosine (m5C) level, measured in circulating cell-free DNA (ccfDNA) as a distinct feature of thyroid gland-related disorders, including thyroiditis, benign nodule, and malignant nodule.Material and Methods: The study included 75 patients with 30 benign nodules, 30 thyroiditis, and 15 thyroid cancers; 19 subjects were evaluated as a control group. We collected peripheral blood samples from three disease groups and the controls, and then separated the plasma from the whole blood. We measured m5C in ccfDNA purified from plasma samples of patients and healthy individuals.Results: The level of m5C, measured in thyroiditis patients was significantly different from those measured in the control group, malignant and benign patients. We observed hypomethylation in benign and malignant patients when compared with the control group. However, there was no significant difference between the malignant patients and the control group and between the benign patients and the control group. After comparison of disease groups, we observed that there was no statistically significant difference between benign and malignant patients. We observed a statistically significant difference between thyroiditis and malignant patients (p<0.01) and between thyroiditis and benign patients (p=0.001).Discussion: Very few studies have reported that DNA methylation is an epigenetic mechanism in thyroiditis patients. Here, we reported that the level of m5C of ccfDNA could be used as a biomarker for thyroiditis. Further studies are required with the higher number of malign and benign patients to investigate the differences between patients with nodules and healthy individuals.