Increased YKL-40 levels are linked with disease severity of initially diagnosed Graves' disease

Background: YKL-40, which is also known as Chitiniase 3-like 1, has been found to be up-regulated in many autoimmune diseases including asthma, systemic sclerosis and systemic lupus, etc. However, the relationship between serum levels of YKL-40 and one another common autoinmmue thyroid disease - Graves' disease (GD) has not yet been investigated. Objective: The current study was performed to investigate the correlation of serum YKL-40 levels with disease severity of initially diagnosed GD. Methods: A total of 142 newly diagnosed active GD and 137 healthy individuals were enrolled in the study. Methimazole was given to 55 GD patients and then 2-month study of follow-up was performed. A commercial ELISA kit was applied for the detection of YKL-40 in serum. Degree of goiter was assessed according to Pérez's Grade. Receiver operating characteristic (ROC) curve analysis was carried out to detect the diagnostic value of serum YKL-40 with regard to goiter degree. The velocity of the peak systolic blood-flow and the thyroid tissue blood flow (TBF) were examined using Color Flow Doppler ultrasonography (CFDU). Results: The patients with GD exhibited dramatically higher YKL-40 in serum compared to those of healthy controls (606.1 ± 149.8 pg/mL vs. 397.4 ± 95.1 pg/mL, P