miRNA-21 and miRNA-27b Expression in Saliva of Patients with Oral Lichen Planus: A Systematic Review

Oral lichen planus (OLP) is a chronic inflammatory disorder of the oral mucosa with a recognized risk of malignant transformation. MicroRNAs, particularly miRNA-21 and miRNA-27b, have been implicated in the pathogenesis and progression of various diseases, including OLP. Their altered expression in saliva may provide diagnostic and prognostic insights for this condition. This systematic review examines the expression profiles of miRNA-21 and miRNA-27b in the saliva of OLP patients to assess their potential as biomarkers. The review was conducted in accordance with PRISMA guidelines and was registered in the PROSPERO database. A comprehensive search was conducted in PubMed, Embase, and Scopus using specific keywords. Retrieved titles and abstracts were screened based on predefined eligibility criteria, and relevant studies were analyzed. The initial search identified 71 studies. After screening, 17 abstracts were selected for full-text review. Following evaluation, 11 studies were excluded, resulting in 6 studies being included. Findings indicate a consistent upregulation of miRNA-21 and a downregulation of miRNA-27b in OLP saliva samples. These alterations suggest a potential role in disease pathogenesis and risk assessment. The dysregulation of miRNA-21 and miRNA-27b in OLP underscores their potential as salivary biomarkers for diagnosis and disease monitoring. Moreover, the non-invasive nature of salivary miRNAs offers promising clinical applications, enhancing early detection and personalized management strategies for OLP.