Pemphigoid Antibodies in Patients with Oral Lichen Planus: A Systematic Review

Background/Objectives: Lichen Planus Pemphigoides (LPP) represents a rare variant of Oral Lichen Planus in which the typical pemphigoid-associated antibodies, BP180 and BP230, are present. The objectives of this Systematic Review are to analyze the data currently available in the literature on this rare condition, with the aim of laying the groundwork for future investigations and research. Methods: This Systematic Review was registered in the International Prospective Register of Systematic Reviews (PROSPERO) under the registration number CRD420251133018. Subsequently, a search was conducted on PubMed/Medline, Scopus, and Ovid using specific keywords combined with Boolean operators. Articles published up to 2025 were included. The following types of studies were considered eligible: case reports, clinical conferences, clinical studies, clinical trials, controlled clinical trials, letters, multicenter studies, observational studies, randomized controlled trials, and human-based studies. Book chapters, systematic reviews, narrative reviews, in vitro studies, and animal models were excluded. Results: A total of 67 articles were initially identified; following thorough review and exclusion, 20 articles were retained. The patient data extracted from these selected studies were used to construct a table in which patients were categorized according to both qualitative and quantitative variables. The results highlight that LPP is a condition requiring a complex diagnostic process involving both histological examination and serological testing (Immunofluorescence and Enzyme-Linked Immunosorbent Assay-ELISA). Conclusions: Furthermore, with the advent of immunotherapy, an increasingly well-documented new category of drug-induced LPP has emerged, associated with PD-1 and PD-L1 inhibitors.