The Evaluation of the Level of C3 and C4 Complements in Unstimulated Saliva of Patients with Oral Lichen Planus

Background and Objectives: Deficiency in the complement system can lead to some autoimmune diseases, such as systemic lupus erythematosus. The purpose of this study was to investigate the levels of C3 and C4 complements in unstimulated saliva of individuals with oral lichen planus (OLP) and healthy subjects. Methods: In this case-control study, 31 healthy individuals and 31 patients with OLP entered the study. The values of C3 and C4, were measured using immunoturbidimetric method, and statistical analysis of data was carried out by t- and ROC tests.   Results: The mean concentrations of C3 and C4 in unstimulated saliva in patients with OLP, were significantly lower than the control group. The C4 cut-off point was obtained to distinguish patients from healthy individuals, 0.78 mg/dL with a sensitivity of 76 and a specificity of 55.   Conclusion: The levels of C3 and C4 complement proteins were low in OLP. Therefore, it seems that these complements are involved in the pathogenesis of OLP and may be considered as potential biological markers for the diagnosis of OLP.