Fibrinogen Demonstration in Oral Lichen Planus: An Immunofluorescence Study on Archival Tissues.

BACKGROUND Lichen planus is a premalignant condition with minimal diagnostic aids. This study is an attempt to use paraffin embedded sections of lichen planus with immunofluorescein stain and to evaluate the immunofluorescent sections to establish pattern of fibrinogen deposition. MATERIALS AND METHODS Thirty-five paraffin embedded sections of old and new cases of oral lichen planus (study group) and five normal oral mucosa (control group) were chosen. Two sections of each (H & E) case were taken, one was stained with hematoxylin and eosin and another with fluorescein isothiocynate conjugate (FITC) polyclonal rabbit antibody against fibrinogen. Fluorescent findings were examined with a fluorescent microscope. RESULTS A high statistical significant correlation was found in respect to fluorescence positivity, intensity of fluorescence and distribution of fluorescence each with p < 0.0001 and fluorescence at blood vessel walls (p = 0.0003). CONCLUSION This study suggested that paraffin embedded sections can be successfully used in direct immunofluorescence staining in routine set up where only formalin fixed tissues are received. CLINICAL SIGNIFICANCE Paraffin embedded sections can be successfully used in direct immunofluorescence staining when only formalin fixed tissues are received.