Xie, Fangyi

AbstractVulvar lichen planus (VLP) is a chronic inflammatory disease which adversely affects patients' quality of life. The pathogenesis of VLP is unknown although Th1 immune response has been implicated. We aimed to discover specific tissue‐based protein biomarkers in VLP compared to normal vulvar tissue (NVT), vulvar lichen sclerosus (VLS) and oral lichen planus (OLP). We used laser capture microdissection‐liquid chromatography‐ tandem mass spectrometry to assess protein expression in fixed lesional mucosal specimens from patients with VLP (n = 5). We then compared proteomic profiles against those of NVT (n = 4), VLS (n = 5), OLP (n = 6) and normal oral mucosa (n = 5), previously published by our group. IL16, PTPRC, PTPRCAP, TAP1 and ITGB2 and were significantly overexpressed in VLP compared to NVT. Ingenuity pathway analysis identified antigen presentation and integrin signalling pathways. Proteins overexpressed in both VLP versus NVT and OLP versus NOM included IL16, PTPRC, PTPRCAP, TAP1, HLA‐DPB1, HLA‐B and HLA‐DRA. This proteomic analysis revealed several overexpressed proteins in VLP that relate to Th1 autoimmunity, including IL16. Overlapping pathways, including those involving IFNγ and Th1 signalling, were observed between VLP, VLS, and OLP.

AbstractIgA vasculitis is a small‐vessel vasculitis subtype with increased risk of systemic involvement. We aimed to investigate if any light‐microscopic features can predict the presence of perivascular granular IgA deposits on direct immunofluorescence (DIF) microscopy. We performed a retrospective search of cutaneous pathology reports from our internal and consultation practice (January 1, 2010–October 5, 2021) with a diagnosis of leukocytoclastic vasculitis and accompanying DIF. A blinded dermatopathologist reviewed standard microscopy slides for predetermined histopathological features. Fifty‐six biopsies (48 patients) and 56 biopsies (42 patients) met inclusion criteria for IgA+ and IgA−, respectively. The presence of eosinophils and mid and deep dermal inflammation were statistically more associated with IgA− (41/56 [73.2%] and 31/56 [55.4%], respectively) than IgA+ cases (28/56 [50.0%] and 14/56 [25.0%]; p = 0.049 and 0.006, respectively, chi‐squared test). Other microscopic criteria recorded were not significantly different between the two groups (p > 0.05, chi‐squared and Fisher's exact tests). In this retrospective study of 112 cases, we found that while the absence of eosinophils and absence of mid‐ and deep inflammation were correlated with increased likelihood of IgA perivascular deposition on DIF, no other histopathological features on light microscopy tested could reliably predict the presence of IgA perivascular deposition on DIF. Therefore, DIF remains a necessary component for the accurate diagnosis of cutaneous IgA vasculitis.

AbstractOral lichen planus (OLP) confers an approximately 1% risk of transformation to oral squamous cell carcinoma (OSCC). Early identification of high‐risk OLP would be very helpful for optimal patient management. We aimed to discover specific tissue‐based protein biomarkers in patients with OLP who developed OSCC compared to those who did not. We used laser capture microdissection– and nanoLC–tandem mass spectrometry to assess protein expression in fixed lesional mucosal specimens in patients with indolent OLP (no OSCC after at least 5‐year follow‐up, n = 6), transforming OLP (non‐dysplastic epithelium with lichenoid inflammation marginal to OSCC, n = 6) or normal oral mucosa (NOM, n = 5). Transforming OLP protein profile was enriched for actin cytoskeleton, mitochondrial dysfunction and oxidative phosphorylation pathways. CA1, TNNT3, SYNM and MB were overexpressed, and FBLN1 was underexpressed in transforming OLP compared with indolent OLP. Integrin signalling and antigen presentation pathways were enriched in both indolent and transforming OLP compared with NOM. This proteomic study provides potential biomarkers, such as CA1 overexpression, for higher‐risk OLP. While further validation studies are needed, we propose that epithelial–mesenchymal transition may be involved in OLP carcinogenesis.

Abstract Background Pemphigoid gestationis (PG) and polymorphic eruption of pregnancy (PEP) are pregnancy‐related dermatoses. Definitive diagnosis often relies upon histopathology and direct immunofluorescence (DIF). PG is associated with fetal and neonatal risks, while PEP confers minimal risk. Objective We aimed to compare histopathologic features to determine key differentiators. Methods A retrospective cohort study of PG and PEP cases, with accompanying DIF, conducted from 1995 to 2020. Skin biopsies were examined independently in a blinded fashion by two dermatopathologists for a list of histopathological features. Results Twenty‐one cases of PG and 10 cases of PEP were identified. PG had significantly denser eosinophils than PEP (mean 155 vs. 48 cells/5 hpf; p < 0.018). PG was also noted to have eosinophilic spongiosis and eosinophils at the dermal–epidermal junction more frequently compared to PEP (80% PG vs. 10% PEP; p < 0.001). A mean cutoff value of 86 eosinophils and a mean optimal sensitivity and specificity of 81% and 83%, respectively, for eosinophils density's diagnostic power of PEP versus PG were achieved. Subepithelial separation was exclusively seen in PG (40% vs. 0%; p < 0.007). Conclusion Eosinophilic spongiosis, eosinophilic epitheliotropism, and dense superficial dermal eosinophils were diagnostic of PG. Given overlapping clinicopathologic features, however, DIF results with clinicopathologic correlation, remain the gold standard.

AbstractVulvar lichen sclerosus (VLS) confers approximately 3% risk of malignant transformation to vulvar squamous cell carcinoma (VSCC). We used unbiased proteomic methods to identify differentially expressed proteins in tissue of patients with VLS who developed VSCC compared to those who did not. We used laser capture microdissection‐ and nanoLC‐tandem mass spectrometry to assess protein expression in individuals in normal vulvar tissue (NVT, n = 4), indolent VLS (no VSCC after at least 5 years follow‐up, n = 5) or transforming VSCC (preceding VSCC, n = 5). Interferon‐γ and antigen‐presenting pathways are overexpressed in indolent and transforming VLS compared to NVT. There was differential expression of malignancy‐related proteins in transforming VLS compared to indolent VLS (CAV1 overexpression, AKAP12 underexpression), particularly in the EIF2 translation pathway, which has been previously implicated in carcinogenesis. Results of this study provide additional molecular evidence supporting the concept that VLS is a risk factor for VSCC and highlights possible future biomarkers and/or therapeutic targets.

AbstractBackgroundOral lichen planus (OLP), a World Health Organization (WHO)‐classified oral potentially malignant condition, confers a 1% risk of transformation to oral squamous cell carcinoma (OSCC). There does not appear to be a consensus understanding of the underlying molecular events. This scoping review aimed to identify critical molecular pathways and highlight gaps in existing knowledge on malignant transformation in OLP.MethodsFollowing Preferred Reporting Items for Systematic Reviews and Meta‐Analysis Protocols (PRISMA‐P) guidelines, a comprehensive literature search and methodical screening identified 61 relevant studies detailing molecular differences between OLP and OSCC.ResultsMolecular changes shared between OLP and OSCC included those affecting cellular proliferation (altered p53 expression, hypermethylation of p16/CDKN2A, MYC gains, increased ki‐67), apoptosis (increased bcl‐2 and survivin expression), extracellular matrix (ECM) remodeling (increased matrix metalloproteinase [MMP] expression), and transcriptional control (altered bmi1 and microRNA [miRNA] expression). In addition, some molecular alterations accumulated incrementally from control to OLP to OSCC or were present in higher‐risk erosive variants of OLP or transformed OLP. Few studies included rigorous diagnostic inclusion criteria or unbiased discovery methods.ConclusionsResults of this review support the potentially malignant nature of OLP and imply that molecular events associated with malignant transformation may be heterogeneous. In addition, findings in this review highlight the need for additional studies using rigorous diagnostic inclusion criteria and unbiased discovery methods to further understand this process.

AbstractBackgroundOral lichen planus confers a 1% risk of transformation to oral squamous cell carcinoma. While prior exome sequencing studies have identified multiple genetic mutations in oral squamous cell carcinoma, mutational analyses of lichen planus‐derived OSCC are lacking. We sought to clarify genomic events associated with oral lichen planus transformation.MethodsUsing rigorous diagnostic criteria, we retrospectively identified patients with non‐transforming oral lichen planus (i.e., known to be non‐transforming with 5 years of clinical follow‐up; n = 17), transforming oral lichen planus (tissue marginal to oral squamous cell carcinoma, n = 9), or oral squamous cell carcinoma arising in lichen planus (n = 17). Gene mutational profiles derived from whole‐exome sequencing on fixed mucosal specimens were compared among the groups.ResultsThe four most frequently mutated genes in transforming oral lichen planus and oral squamous cell carcinoma (TP53, CELSR1, CASP8, and KMT2D) identified 12/17 (71%) of oral squamous cell carcinomas and 5/9 (56%) of transforming oral lichen planus but were absent in non‐transforming oral lichen planus. We identified other known oral squamous cell carcinoma mutations (TRRAP, OBSCN, and LRP2) but also previously unreported mutations (TENM3 and ASH1L) in lichen planus‐associated oral squamous cell carcinomas.ConclusionsThese findings suggest alterations in DNA damage response and apoptosis pathways underlie lichen planus‐related oral squamous cell carcinoma transformation and are supported by mutational signatures indicative of DNA damage. This study characterized patterns of mutational events present in oral lichen planus associated with squamous cell carcinoma and in squamous cell carcinoma associated with oral lichen planus but not in non‐transforming oral lichen planus.