RESUMEN
OBJECTIVE: To investigate the expression of programmed death-ligands 1 and 2 (PD-L1, PD-L2), programmed death-1 (PD-1), CD8 and granzyme B (GrB), as well as its correlation with the severity of oral lichen planus (OLP). MATERIALS AND METHODS: In a collaborative study, 33 cases of OLP were evaluated according to the latest criteria proposed by the American Academy of Oral and Maxillofacial Pathology (AAOMP/2016) and were submitted to immunohistochemistry. Positivity was measured semiquantitatively (PD-L1, PD-L2) and quantitatively (PD-1, CD8, GrB). The severity of OLP was assessed according to clinical subtype, symptomatology and response to corticosteroid therapy. RESULTS: Most OLPs were considered to be negative for PD-L1 (66.6%), but high expression of PD-L2 (96.9%) by keratinocytes and immunoinflammatory cells was observed. PD-1+ cell density/mm2 was reduced compared to CD8+ cells. A low cytotoxic immune response (CD8:GrB ratio) was also demonstrated. Interestingly, there were fewer GrB+ cells in the intraepithelial region in reticular OLP compared to erosive/bullous OLP. CONCLUSIONS: PD-L1/PD-1 pathways appear to be compromised in OLP due to low PD-L1 expression in most samples. In contrast, PD-L2 overexpression associated with a possible regulation of the cytotoxic immune response suggests an immune tolerance that may contribute to the chronic profile of OLP.
RESUMEN
BACKGROUND: The aim of the present series was to analyze the sociodemographic characteristics, clinicopathologic features, and oral health-related quality of life of 41 individuals with oral lichen planus (OLP). MATERIAL AND METHODS: In a retrospective analysis (1998-2018), individuals with a clinical diagnosis of OLP from a referral service of Oral Medicine of Brazil were invited for follow-up. The individuals were assessed using the Oral Health Impact Profile-14 (OHIP-14) form. Histopathological data were reviewed according to the latest criteria proposed by the American Academy of Oral and Maxillofacial Pathology (AAOMP/2016). RESULTS: This series mainly consisted of females (70.7%) in their forties (31.7%). The buccal mucosa (68.2%) was the most commonly affected site. Reticular (56.1%) and erosive (34.3%) appearances were the most frequent. According to OHIP-14, individuals with OLP at multiple sites in the oral cavity showed worse values in the handicap domain and those who did not respond to corticosteroids showed a higher score on the psychological discomfort domain. CONCLUSIONS: The findings of the present study, using the AAOMP/2016 criteria, agree with case series and retrospective studies reported in the literature. Besides, OLP in its more severe clinical forms had an influence on patient quality of life. Key words:Diagnosis, epidemiology, oral lichen planus, oral mucosa, quality of life.