Serum thiol levels and thiol/disulfide homeostasis in patients with rheumatic mitral valve disease and healthy subjects

Background: Rheumatic mitral valve disease (RMVD) is the most common presentation of rheumatic heart disease (RHD). Inflammation and fibrosis processes also play significant roles in its pathogenesis. Recent studies showed that thiols and thiol-disulfide are promising novel oxidative stress markers. Objectives: The present study aimed to evaluate differences in the serum thiol and thiol-disulfide levels in patients with RMVD and the control group. Methods: Ninety-two patients with RMVD were enrolled in the study. Fifty-four healthy subjects, age, and gender-matched with the study group, were also included in the study as a control group. This study investigated thiol levels in patients with RMVD and the control group. P-values lower than 0.05 were considered statistically significant. Results: The patients with RMVD presented higher systolic pulmonary artery pressure (SPAP) and left atrial (LA) diameter levels than the control group. Native thiol (407±83 μmol/L vs. 297±65 μmol/L, p<0.001) and total thiol (442±82 μmol/L vs. 329±65 μmol/L, p<0.001) levels were higher in the control group. Disulfide (16.7±4.9 μmol/L vs. 14.8±3.7 μmol/L, p=0.011) levels were higher in the group of patients with RMVD. A positive correlation was found between disulfide/ native and disulfide/total thiols ratio with SPAP, LA diameter, and MS severity. Disulfide/total thiols ratio was significantly higher in patients with severe MS than with mild to moderate MS patients. Conclusions: To the best of our knowledge, this is the only study of its kind that has evaluated thiol/disulfide homeostasis as a novel predictor, which was more closely related to RMVD and the severity of MS.