Estimation of salivary myeloid-related protein (calprotectin) level in patients with oral lichen planus: a case-control study.

Objectives: Oral lichen planus (OLP) is a chronic, autoimmune disease that causes inflammation in the oral mucosa. It has a 1.14% chance of malignant transformation. The pathogenesis of OLP is unclear. Myeloid-related protein (calprotectin) is a protein complex found in various cells and potentially serves as a biomarker for inflammation. We aimed to detect the relationship between salivary calprotectin levels and OLP.

Materials and methods: Thirty patients with OLP and 30 age- and sex-matched healthy controls were recruited from our affiliated Dermatology outpatient clinics. Unstimulated whole saliva was collected (09:00 AM-12:00 PM) under standardized pre-collection restrictions, calprotectin concentration was measured by ELISA, and levels were compared between patients and controls.

Results: Patients with OLP had higher salivary calprotectin levels than controls, with age and disease duration positively correlated. However, we found no significant correlation between salivary calprotectin levels and cutaneous involvement, sex, number of oral sites involved, or types of OLP. The study found substantial differences in calprotectin levels between cases with coexisting nail involvement and those without nail involvement. ROC analysis yielded AUC = 1.00 with an optimal cut-off of > 32 ng/mL (100% sensitivity and 100% specificity).

Conclusion: Higher salivary calprotectin levels in OLP patients than in healthy subjects suggest that salivary calprotectin may contribute to OLP pathogenesis and can be helpful in disease diagnosis and monitoring.

Clinical relevance: The ability to non-invasively measure salivary calprotectin (S100A8/A9) levels makes it an attractive option for diagnostic and monitoring purposes.