Immunofluorescence Study in Oral Lichen Planus and Oral Lichenoid Reactions

Oral lichen planus (OLP) is an autoimmune disease of oral mucosa. Oral lichenoid reactions (OLR) are considered as a variant of OLP. They may be regarded as a disease by itself or as an exacerbation of an existing OLP, by the presence of medication or dental materials. They are indistinguishable, clinically and histologically. Objectives: To describe the fluorescence patterns in idiopathic OLP and OLR using direct immunofluorescence (DIF) and the fluorescence pattern of basal cells in idiopathic OLP and OLR using indirect immunofluorescence (IIF) technique. To investigate the relationship between OLR (drug related) and contact allergy to dental materials (epicutaneous patch testing) using DIF and IIF. Methods: 28 subjects were involved. Oral biopsy were taken and bisected. One of the sections was processed for standard light microscopic examination and the other half was quick frozen in liquid nitrogen for DIF examination. 5 ml of venous blood were taken and subjected to centrifugation to separate the serum. The serum was used for IIF examination. 21 patients were sent for patch test to various components of dental materials. Results: 19 patients diagnosed with OLP showed linear pattern of positive fluorescence to fibrinogen at the basement membrane zone with DIF. 6 out of 7 sections from OLR showed similar features as in idiopathic OLP. IIF showed negative result in all specimens of OLP and OLR. 2 patients were patch tested positive for nickel sulphate and 2 patients were positive for components of acrylic resin. Conclusion: DIF was positive in all idiopathic OLP and majority of OLR, but the fluorescence pattern show no difference. IIF was negative in all cases. Cutaneous patch test may aid in differentiating OLP and OLR, but further study with bigger sample size is needed. This study was supported by University of Malaya's grant ( Vot F: F0201/2003D).