Single-cell RNA sequencing of chronic idiopathic erythroderma defines disease-specific markers.

Background: Chronic erythroderma is a potentially life-threatening condition that can be caused by various diseases, but approximately 30% of cases remain idiopathic, often with insufficient treatment options.

Objective: We sought to establish a molecular disease map of chronic idiopathic erythroderma (CIE).

Methods: We performed single-cell RNA sequencing combined with T-cell receptor sequencing of blood and skin from 5 patients with CIE and compared results with 8 cases of erythrodermic cutaneous T-cell lymphoma (eCTCL), 15 cases of moderate to severe atopic dermatitis, 10 cases of psoriasis, and 20 healthy control individuals.

Single-cell RNA sequencing comparison of CD4+, CD8+ and T-cell receptor γδ+ cutaneous T-cell lymphomas reveals subset-specific molecular phenotypes.

Background: Malignant clones of primary cutaneous T-cell lymphomas (CTCL) can show a CD4+, CD8+ or T-cell receptor (TCR)-γδ+ phenotype, but their individual impact on tumour biology and skin lesion formation remains ill defined.

Objectives: To perform a comprehensive molecular characterization of CD4+ vs. CD8+ and TCR-γδ+ CTCL lesions.

Single-cell RNA sequencing defines disease-specific differences between chronic nodular prurigo and atopic dermatitis.

Background: Chronic nodular prurigo (CNPG) is an inflammatory skin disease that is maintained by a chronic itch-scratch cycle likely rooted in neuroimmunological dysregulation. This condition may be associated with atopy in some patients, and there are now promising therapeutic results from blocking type 2 cytokines such as IL-4, IL-13, and IL-31.

Objectives: This study aimed to improve the understanding of pathomechanisms underlying CNPG as well as molecular relationships between CNPG and atopic dermatitis (AD).

Single-cell RNA sequencing analysis of a COVID-19-associated maculopapular rash in a patient with psoriasis treated with ustekinumab.

Coronavirus disease 2019 (COVID-19) primarily affects the respiratory system but extrapulmonary manifestations, including the skin, have been well documented. However, transcriptomic profiles of skin lesions have not been performed thus far. Here, we present a single-cell RNA sequencing analysis in a patient with COVID-19 infection with a maculopapular skin rash while on treatment with the interleukin (IL)-12/IL-23 blocker ustekinumab for his underlying psoriasis.

Single-cell RNA sequencing reveals markers of disease progression in primary cutaneous T-cell lymphoma.

Background: In early-stage mycosis fungoides (MF), the most common primary cutaneous T-cell lymphoma, limited skin involvement with patches and plaques is associated with a favorable prognosis. Nevertheless, approximately 20-30% of cases progress to tumors or erythroderma, resulting in poor outcome. At present, factors contributing to this switch from indolent to aggressive disease are only insufficiently understood.

Single-cell RNA sequencing profiling in a patient with discordant primary cutaneous B-cell and T-cell lymphoma reveals micromilieu-driven immune skewing.

Background: Primary cutaneous lymphomas comprise a heterogeneous group of B-cell and T-cell malignancies which often show an indolent course, but can progress to aggressive disease in a subset of patients. Diagnosis is often delayed owing to clinical and histopathological similarities with benign inflammatory conditions. Especially during early disease, cancer cells are present at relatively low percentages compared with the inflammatory infiltrate, an interplay that is currently only insufficiently understood.

Single-Cell RNA Sequencing Reveals Tissue Compartment-Specific Plasticity of Mycosis Fungoides Tumor Cells.

Mycosis fungoides (MF) is the most common primary cutaneous T-cell lymphoma. While initially restricted to the skin, malignant cells can appear in blood, bone marrow and secondary lymphoid organs in later disease stages. However, only little is known about phenotypic and functional properties of malignant T cells in relationship to tissue environments over the course of disease progression.

Spontaneously Resolved Atopic Dermatitis Shows Melanocyte and Immune Cell Activation Distinct From Healthy Control Skin.

Atopic dermatitis (AD) typically starts in infancy or early childhood, showing spontaneous remission in a subset of patients, while others develop lifelong disease. Despite an increased understanding of AD, factors guiding its natural course are only insufficiently elucidated. We thus performed suction blistering in skin of adult patients with stable, spontaneous remission from previous moderate-to-severe AD during childhood.

Persistence of mature dendritic cells, T2A, and Tc2 cells characterize clinically resolved atopic dermatitis under IL-4Rα blockade.

Therapeutic options for autoimmune diseases typically consist of broad and targeted immunosuppressive agents. However, sustained clinical benefit is rarely achieved, as the disease phenotype usually returns after cessation of treatment. To better understand tissue-resident immune memory in human disease, we investigated patients with atopic dermatitis (AD) who underwent short-term or long-term treatment with the IL-4Rα blocker dupilumab.