[Ultraviolet radiation in the pathogenesis of lupus erythematosus]. / UV-induzierte Pathogenese des Lupus erythematodes.

Photosensitivity represents an increased inflammatory reaction to sunlight, which can be observed particularly in the autoimmune disease lupus erythematosus. Cutaneous lupus erythematosus (CLE) can be provoked by ultraviolet (UV) radiation and can cause both acute, nonscarring and chronic, scarring skin changes. In systemic lupus erythematosus, on the other hand, provocation by UV radiation can lead to flare or progression of systemic involvement. The etiology of lupus erythematosus is multifactorial and includes genetic, epigenetic and immunologic mechanisms. In this review, we address the effect of UV radiation on healthy skin and photosensitive skin using the example of lupus erythematosus. We describe possible mechanisms of UV-triggered immune responses that could offer therapeutic approaches. Currently, photosensitivity can only be prevented by avoiding UV exposure itself. Therefore, it is important to better understand the underlying mechanisms in order to develop strategies to counteract the deleterious effects of photosensitivity.

Gain-of-function human UNC93B1 variants cause systemic lupus erythematosus and chilblain lupus.

UNC93B1 is a transmembrane domain protein mediating the signaling of endosomal Toll-like receptors (TLRs). We report five families harboring rare missense substitutions (I317M, G325C, L330R, R466S, and R525P) in UNC93B1 causing systemic lupus erythematosus (SLE) or chilblain lupus (CBL) as either autosomal dominant or autosomal recessive traits. As for a D34A mutation causing murine lupus, we recorded a gain of TLR7 and, to a lesser extent, TLR8 activity with the I317M (in vitro) and G325C (in vitro and ex vivo) variants in the context of SLE. Contrastingly, in three families segregating CBL, the L330R, R466S, and R525P variants were isomorphic with respect to TLR7 activity in vitro and, for R525P, ex vivo. Rather, these variants demonstrated a gain of TLR8 activity. We observed enhanced interaction of the G325C, L330R, and R466S variants with TLR8, but not the R525P substitution, indicating different disease mechanisms. Overall, these observations suggest that UNC93B1 mutations cause monogenic SLE or CBL due to differentially enhanced TLR7 and TLR8 signaling.

[Paraneoplastic subacute cutaneous lupus erythematosus]. / Paraneoplastischer subakut kutaner Lupus erythematodes.

The genesis of subacute cutaneous lupus erythematosus (SCLE) is multifactorial and includes idiopathic, drug-related and paraneoplastic etiologies. This article reports the case of a 70-year-old female patient with paraneoplastic SCLE in whom a lung adenocarcinoma was detected during the extended examination. A paraneoplastic SCLE should be considered when a patient with SCLE presents with lesions in regions of the skin not exposed to sunlight and beginning B symptoms.

An update on clinical trials for cutaneous lupus erythematosus.

Cutaneous lupus erythematosus (CLE) comprises dermatologic manifestations that may occur independently or with systemic lupus erythematosus (SLE). Despite advancements in refining CLE classification, establishing precise subtype criteria remains challenging due to overlapping presentations and difficulty in distinguishing morphology. Current treatments encompass preventive measures, topical therapies, and systemic approaches. Hydroxychloroquine and glucocorticoids are the sole US Food and Drug Administration (FDA)-approved medications for CLE, with numerous off-label treatments available. However, these treatments are often not covered by insurance, imposing a significant financial burden on patients. The exclusion of most CLE patients, particularly those without concurrent SLE, from trials designed for SLE has resulted in a lack of targeted treatments for CLE. To develop effective CLE treatments, validated outcome measures for tracking patient responsiveness are essential. The Cutaneous Lupus Erythematosus Disease Area and Severity Index is widely utilized for its reliability, validity, and ability to differentiate between skin activity and damage. In contrast, the FDA mandates the use of the Investigator's Global Assessment, a five-point Likert scale related to lesion characteristics, for skin-related therapeutic trials. It requires the disease to resolve or almost completely resolve to demonstrate improvement, which can be difficult when there is residual erythema or incomplete clearance that is meaningfully improved from a patient perspective. Various classes of skin lupus medications target diverse pathways, allowing tailored treatment based on the patient's lupus inflammatory profile, resulting in improved outcomes. Promising targeted therapeutic drugs include anifrolumab (anti-type 1 interferon), deucravacitinib (allosteric tyrosine kinase 2 inhibitor), litifilimab (plasmacytoid dendritic cell-directed therapy), iberdomide (cereblon-targeting ligand), and belimumab (B-cell directed therapy). Despite the significant impact of CLE on quality of life, therapeutic options remain inadequate. While promising treatments for cutaneous lupus are emerging, it is crucial to underscore the urgency for skin-focused treatment outcomes and the implementation of validated measures to assess therapeutic effectiveness in clinical trials.

International exchange on the clinical practice and research of rheumatic skin diseases: A report of the 5th International Conference of Cutaneous Lupus Erythematosus.

The 5th International Conference of Cutaneous Lupus Erythematosus was held in Tokyo, Japan on May 9 and 10, 2023. The latest topics on the pathogenesis, diagnosis, assessment, and treatment of cutaneous lupus erythematosus, dermatomyositis, and scleroderma (systemic sclerosis, morphea) were presented by experts in each field and new developments discussed. In these rheumatic skin diseases, many clinical trials of novel therapies targeting cytokines, signaling molecules, plasmacytoid dendritic cells, B cells, and other molecules are currently underway, and standardization of outcome assessment was discussed. In addition, the selection of the therapeutic agents available for the diversity of each case is becoming more important, together with the ongoing pathophysiological analysis of the diseases. The achievements of this conference will further promote the development of clinical practice and research in rheumatic skin diseases through international exchange among researchers. We hope that by reporting a summary of the conference in this manuscript, we can share its contents with readers.

Recent findings about antimalarials in cutaneous lupus erythematosus: What dermatologists should know.

Antimalarials (AMs), particularly hydroxychloroquine (HCQ) and chloroquine (CQ), are the cornerstone of the treatment for both systemic lupus erythematosus (SLE) and cutaneous lupus erythematosus (CLE). HCQ and CQ are recommended as first-line oral agents in all CLE guidelines. Initially thought to have potential therapeutic effects against COVID-19, HCQ has drawn significant attention in recent years, highlighting concerns over its potential toxicity among patients and physicians. This review aims to consolidate current evidence on the efficacy of AMs in CLE. Our focus will be on optimizing therapeutic strategies, such as switching from HCQ to CQ, adding quinacrine to either HCQ or CQ, or adjusting HCQ dose based on blood concentration. Additionally, we will explore the potential for HCQ dose reduction or discontinuation in cases of CLE or SLE remission. Our review will focus on the existing evidence regarding adverse events linked to AM usage, with a specific emphasis on severe events and those of particular interest to dermatologists. Last, we will discuss the optimal HCQ dose and the balance between preventing CLE or SLE flares and minimizing toxicity.

A Case Report of Neonatal Lupus Erythematosus with Liver Function Damage and Cytomegalovirus Colonization.

BACKGROUND: Neonatal lupus erythematosus (NLE) is an acquired autoimmune disease. NLE with liver function damage and cytomegalovirus colonization is rarely reported. METHODS: This case describes a newborn male's laboratory testing found sustained liver function damage when he came to see the doctor due to oral candidiasis. The cause was identified through clinical symptoms, laboratory tests, auxiliary examinations, and family history of the patient. RESULTS: The final diagnosis of the child was NLE with liver function damage and cytomegalovirus colonization according to comprehensive analysis and follow-up observation. CONCLUSIONS: NLE and cytomegalovirus colonization can both lead to liver function damage. When the organ function of newborns is abnormal, it is necessary to promptly investigate the cause and determine whether it is NLE.

Superficial and Bullous Neutrophilic Dermatoses: Sneddon-Wilkinson, IgA Pemphigus, and Bullous Lupus.

Sneddon-Wilkinson disease (SWD), IgA pemphigus, and bullous systemic lupus erythematosus (BSLE) are superficial and bullous neutrophilic dermatoses. They are all characterized by sterile neutrophilic infiltrate but differ in the level of skin affected and presence of autoantibodies. Both SWD and IgA pemphigus present with grouped flaccid pustules and have epidermal involvement; it is unclear whether they are distinct or exist on a spectrum of the same disease. IgA pemphigus is distinguished from SWD by positive direct immunofluorescence showing intercellular IgA deposition. BSLE presents with tense bullae, dermal neutrophilic infiltrate, and direct immunofluorescence showing linear IgG deposition along the dermal-epidermal junction.

Incidence and medical costs of lupus in Spanish hospitals: a retrospective database analysis.

BACKGROUND: This study aimed to assess the comorbidity profile, use of healthcare resources and medical costs of patients with systemic lupus erythematosus (SLE) and cutaneous lupus erythematosus (CLE) treated at the hospital level in Spain. METHODS: Admission records of patients with SLE and CLE that were registered between January 2016 and December 2020 were obtained from a Spanish hospital discharge database and analyzed in a retrospective multicenter study. RESULTS: 329 patients met the criteria; 64.44% were female and 35.56% were male, with a median age of 54.65 years. Mean Charlson comorbidity index (CCI) was 2.75 in the index admission. 31.61% of the patients suffered essential hypertension, 21.96% suffered asthma and 19.76% suffered hyperlipidemia. Mortality rate was 3.95%. The most common medical procedure was heart ultrasound (19.45%) and introduction in peripheral vein of anti-inflammatory with a percutaneous approach (17.93%). Mean admission cost was €6355.99. CONCLUSIONS: Lupus patients showed a higher incidence and prevalence in the female population, with associated cardiac diseases as the main secondary conditions.

Diffuse Cutaneous Mastocytosis: A Current Understanding of a Rare Disease.

Mastocytosis is a heterogeneous disease characterized by the expansion and accumulation of neoplastic mast cells in various tissues. Diffuse cutaneous mastocytosis (DCM) is a rare and most severe form of cutaneous mastocytosis, which typically occurs in childhood. There have been reports of a familial DCM with specific gene mutations, indicating both sporadic and hereditary factors involved in its pathogenesis. DCM is associated with severe MC mediator-related symptoms and an increased risk of anaphylaxis. The diagnosis is based on the appearance of skin lesions, which typically show generalized thickening, erythroderma, blistering dermographism, and a positive Darier's sign. Recognition, particularly in infants, is challenging due to DCMs resemblance to other bullous skin disorders. Therefore, in unclear cases, a skin biopsy is crucial. Treatment focuses on symptom management, mainly including antihistamines and mast cell stabilizers. In extremely severe cases, systemic steroids, tyrosine kinase inhibitors, phototherapy, or omalizumab may be considered. Patients should be equipped with an adrenaline autoinjector. Herein, we conducted a comprehensive review of literature data on DCM since 1962, which could help to better understand both the management and prognosis of DCM, which depends on the severity of skin lesions, intensity of mediator-related symptoms, presence of anaphylaxis, and treatment response.