MicroRNA diagnostic value in pemphigus diagnosis

BACKGROUND: Pemphigus is a group of life-threatening, chronic, progressive skin disease. To implement timely and adequate therapy aimed at preserving life and improving its quality, it is necessary to provide a diagnostic test confirming the diagnosis. AIM: This study aimed to compare the expression levels of miR-338-3p and miR-424-5p in patients with pemphigus during therapy and remission, as well as in control groups of patients with other bullous skin diseases and healthy controls, and to evaluate the diagnostic value of miR-338-3p and miR-424-5p expression. MATERIALS AND METHODS: Prospective comparative study was conducted. The study included 20 patients with active pemphigus, 15 patients in remission, 15 healthy control group participants, and 6 patients with other bullous diseases in the active stage. The expression of miRNA-338-3p and miR-424-5p was evaluated by qRT-PCR, cDNA was obtained using StemLoop technology. MicroRNA relative expression levels were analyzed based on its comparison with the expression of U6 gene using 2-ΔΔСT method. RESULTS: The expression levels of miR-338-3p and miR-424-5p were significantly higher in patients with pemphigus active stage compared to all other groups (p 0.001). There was a statistically significant relationship between miR-338-3p expression level and disease severity according to the PDAI index (p 0.001), for miR-424-5p there was also a positive correlation with severity, but with a weaker relationship. ROC analysis showed high diagnostic accuracy of miR-338-3p (AUC 0.94) and miR-424-5p (AUC 0.93) for differentiating between patients with active pemphigus and healthy controls, with sensitivity and specificity of 95.0% and 75.0%, 95.0% and 73.3%, respectively. At week 3 from the start of glucocorticosteroid therapy, miR-338-3p levels were significantly decreased in patients in the active pemphigus (p=0.035), whereas no statistically significant decrease in miR-424-5p was observed. CONCLUSION: miR-338-3p and miR-424-5p are significant in pemphigus as potential biomarkers for diagnosis and severity grade, and the expression level of miR-338-3p can be used to determine the efficacy of pathogenetic therapy.