Clinical and morphological analysis of the state of the hemato-salivary barrier in a biopsy of the buccal mucosa in the erosive-ulcerative form (L43.82) of lichen planus

Background. Erosive-ulcerative lichen planus of the oral mucosa (EUL (L43.82) PL SOR) is a chronic condition characterized by painful lesions, resistance to treatment, and a risk of malignancy. Objective. To conduct a clinical and pathological analysis of the blood-saliva barrier and microenvironment in buccal mucosa biopsy specimens from EUL (L43.82) PL. Material and methods. A two-center, prospective, observational, uncontrolled study allowed us to select 14 individuals from 86 patients with EUL (L43.82) PL with lesions localized to the buccal mucosa (retromolar region). An analysis comparing the relationship between the clinical condition of the mucous membrane and histological analysis of 14 biopsies obtained from the buccal mucosa in erosive and ulcerative lesions was conducted. Histological examination methods were used. The tissues were stained with hematoxylin and eosin, van Gieson, Mallory, and toluidine blue. Immunohistochemical (CD 68, MMP-9, TGF-b, TNF-a, PCNA, HLA-DR) and electron microscopic examinations were performed. Results. In EYA (L43.82) PL, there is a relationship between the presence of clinical signs in the form of an acute inflammatory reaction with tissue destruction, hyperemia and edema, the presence of extensive bleeding erosive-ulcerative lesions of irregular, polygonal shape, covered with a yellow-white fibrinous coating (diameter of erosions 5.21±0.60 cm2, area of hyperemia 6.21±0.79 cm2, reticular network 5.75±0.31 cm2). Pathological signs characterize the presence of an acute inflammatory reaction, high levels of HLA-DR antigens, IQR: 182—190, KV: ±36, fibrosis — MMP-9, Me = 18 IQR: 15—18, KV: ± 5%, TGF-b, Me=80 IQR: 78—91, KV: ±12%, inflammatory cell infiltration — CD 68, Me=73 IQR: 71—76, KV: ±23%. The ducts of the minor salivary glands are obliterated and dystrophic, the hematosalivary barrier is impaired. Conclusion. Histological analysis of biopsy material should be considered one of the stages included in the clinical examination of a patient with EYA (L43.82) PL SOR, allowing for definitive confirmation of the diagnosis in the context of oncological alertness.