Mangold, Aaron

Abstract Introduction Cutaneous lichen planus (cLP) is a T cell—mediated skin disease in which cytotoxic CD8+ T cells attack basal keratinocytes at the dermo-epidermal junction. While studies have characterized T cell subsets in lesional tissue, circulating immune signatures in cLP are incompletely defined. We performed deep immunophenotyping of circulating T-cell subsets to map systemic alterations in cLP patients vs healthy controls. Methods We included 12 treatment-refractory cLP patients (mean age 63.6 ± 13.6 years) and 2 healthy controls (37.5 ± 10.6 years). Whole blood was profiled for 27 markers by flow cytometry. Sequential gating: singlets → live → CD3+ T cells → CD4+/CD8+/γδ; FOXP3+ Tregs were defined within CD4+. Frequencies were expressed as % of the immediate parent population. Group comparisons used two-tailed exact Mann—Whitney tests with Hodges—Lehmann median differences. Results Across frozen specimens, cLP patients exhibited broad T-cell activation. Proliferation increased in CD4 (Ki67+, p < 0.05), CD8 (6.785% vs 0.885%; Δ=5.90; p < 0.05), and Tregs (83.0% vs 46.8%; Δ=34.1; p < 0.05). Intracellular CTLA-4 was higher on CD4 (11.07% vs 2.615%; Δ=8.45; p < 0.05), CD8 (21.05% vs 9.30%; Δ=11.6; p < 0.05), and γδ T cells (47.20% vs 24.45%; Δ=22.75; p < 0.05). CXCL13+ cells expanded in CD4 (28.20% vs 12.45%; Δ=15.5; p < 0.05), CD8 (18.05% vs 3.595%; Δ=14.46; p < 0.05), γδ (2.805% vs 0.465%; Δ=2.285; p < 0.05), and Tregs (7.56% vs 1.17%; Δ=6.39; p < 0.05). Tregs were TBET-high (78.75% vs 61.55%; Δ=17.3; p < 0.05); GITR+ Tregs trended up (p = 0.1978). Conclusion cLP blood displays a CXCL13+, proliferative T-cell signature with increased intracellular CTLA-4 across CD4, CD8, γδ, and Treg compartments. CXCL13 elevation aligns with lesion-level literature implicating CXCL13+ CD8+ T cells that are suppressed in JAK-STAT therapy responders. Tregs exhibit a GITR upregulated, Th1-like phenotype that suggests loss of suppressive capacity, warranting further investigation on whether Treg dysfunction plays a causative role in cLP. Funding Source N/A Topic Categories Immune Mechanisms of Human Disease (HUM)

Abstract Dermatomyositis is driven by overactivation of type I and II interferons and other proinflammatory cytokines that signal via the JAK-STAT pathway. We conducted a 12-week, open-label study of brepocitinib, an oral TYK2/JAK1 inhibitor, in five adults with severe cutaneous dermatomyositis. Treatment was associated with rapid, clinically meaningful improvement in cutaneous disease activity. Single-cell and spatial transcriptomic profiling of lesional skin showed marked suppression of interferon-responsive pathways and inflammatory cell states by week 4. Together with findings from a Phase 3 randomized trial in DM patients with skin and muscle involvement (VALOR, NCT05437263 ), these data support TYK2/JAK1 inhibition as a promising therapeutic strategy for DM.

ImportanceThere exists substantial heterogeneity in outcomes within T stages for patients with cutaneous squamous cell carcinoma (cSCC).ObjectiveTo determine whether a customized generative pretrained transformer model, trained on a comprehensive dataset with more than 1 trillion parameters and equipped with relevant focused context and retrieval augmented generation (RAG), could excel in aggregating and interpreting vast quantities of data to develop a novel class-based risk stratification system that outperforms the current standards.Design, Setting, and ParticipantsTo build the RAG knowledge base, a systematic review of the literature was conducted that addressed risk factors for poor outcomes in cSCC. Using the RAG-enabled generative pretrained transformer (GPT) model, we developed a novel class-based risk stratification system that assigned point values for risk factors, culminating in a GPT-based prognostication system called the artificial intelligence–derived risk score (AIRIS). The system’s performance was validated on a combined prospective and retrospective cohort of 2379 primary cSCC tumors (1996-2023) with at least 36 months of follow-up, against Brigham and Women’s Hospital (BWH) and American Joint Committee on Cancer Staging Manual, eighth edition (AJCC8) systems in stratifying risk for locoregional recurrence (LR), nodal metastasis (NM), distant metastasis (DM), and disease-specific death (DSD).Main Outcomes and MeasuresPerformance metrics evaluated included distinctiveness, homogeneity, and monotonicity, as defined by the AJCC8, as well as sensitivity, specificity, positive predictive value, negative predictive value, accuracy, the area under the receiver operating characteristic curve, and concordance.ResultsThe median age at diagnosis was 73 (IQR, 64-81) years, with 38.5% female patients and 61.5% male patients. The AIRIS prognostication system demonstrated superior sensitivity across all outcomes (LR, 49.1%; NM, 73.7%; DM, 82.5%; and DSD, 72.2%) and the highest area under the receiver operating characteristic curve values (LR, 0.69; NM, 0.81; DM, 0.85; and DSD, 0.80), indicating significantly enhanced discriminative capability compared with the BWH and AJCC8 systems. While all systems were comparably distinctive, the AIRIS prognostication system consistently demonstrated the lowest proportion of tumors exhibiting poor outcomes in low-risk categories, suggesting its improved homogeneity and monotonicity.Conclusions and RelevanceThe results of this diagnostic study suggest that the AIRIS system outperforms the existing BWH and AJCC8 prognostication systems, potentially providing a more effective tool for predicting poor outcomes in cSCC. This study illustrates the potential of large language models in refining prognostic tools, offering implications for treating patients with cancer.