Questions of immunohistochemical characteristics of lichen planus and lichenoid drug eruption of the skin

Sidikov A.A., Zaslavsky D.V., Sadykov A.I., Chuprov I.N., Kozlova D.V., Nasyrov R.A., Timoshchuk E.A.

Tashkent State Dental Institute, Tashkent, Uzbekistan

St.Petersburg State Pediatric Medical University, St.Petersburg, Russian Federation

LCC “Medical clinic XXI century”, St. Petersburg, Russian Federation

North-Western State Medical University named after I.I. Mechnikov, St. Petersburg, Russian Federation

Lichen planus (LP) and lichenoid skin reaction (LR) are papulosquamous dermatoses with similar clinical and histological features. We conducted a prospective study of 33 patients with the classic form of LP and / or LR to develop more precise criteria for differential diagnosis of these diseases. All patients underwent histological and immunohistochemical examination (IHC) of all skin biopsies on paraffin sections using CD4, CD8, CD68, p16, CD207, CD209/DC-SIGN markers. According to the results of histological examination, all patients were divided into 2 groups: patients with LRC (n=18, 10 women and 8 men, average age 45,2 years) were included in the 1 group, the second group consisted of patients with PL (n=12, 7 women and 5 men, average age 50,3 years). The IHC study showed that patients with LR had a more pronounced expression of CD4, CD68, moderate expression of CD207/ Langerin, and a weak reaction of CD209 / DC-Sign antigens compared to the second group, where there was a pronounced expression of CD4, CD8, and CD68 markers. In both groups, the reaction to the p16 antigen was negative. The obtained results imply that CD207 and CD209/DC-Sign markers are the most valuable for accurate and rapid identification of LR. Their usage will allow prompt diagnosis and prescribe specific therapy.