Evaluation of spexin levels in euthyroid patients with Hashimoto thyroiditis and its relation to autoimmunity

Hashimoto thyroiditis (HT) is chronic lymphocytic thyroiditis. Cytokines and chemokines such as tumor necrosis factor-alpha, interferon-gamma, and interleukin-1 beta originating from immune cells are involved in the etiopathogenesis of HT. Spexin (SPX) is a recently identified novel peptide hormone consisting of 14 amino acids and has been demonstrated in follicle epithelial cells in thyroid tissue. SPX has been shown to affect the inflammatory response and play a role in its regulation in various diseases. There is a need for markers for diagnosis and treatment of HT patients with negative antibody levels. We found that there is no study in the literature that investigates the HT and the role of spexin in this inflammatory process. Forty-five patients aged 18 to 70 years with HT or newly diagnosed HT and 42 healthy subjects as the control group were included in the study. Patients in the HT group were divided into 3 categories according to ultrasound findings. Mild heterogeneity was called grade 1 (G1), moderate heterogeneity was called grade 2 (G2), and high heterogeneity was called grade 3 (G3). Laboratory parameters and anthropometric measurements of all patients participating in the study were performed, and SPX was measured by the ELISA method. There was no significant difference between the HT and control groups in terms of SPX levels (P = .27). In HT subgroup analysis, SPX levels were found to be borderline statistically significantly higher in the G2 group, where antibody levels were higher compared to other groups (P = .061). In our study, we evaluated SPX levels in HT patients, which has never been done before in the literature. We found high SPX levels in HT patients with high antibody levels. Multicenter studies with high case series, especially at the tissue level, are needed to fully explain the role of SPX in HT immunoetiopathogenesis and to understand immune-checkpoint pathways more clearly.