British Journal of Dermatology最新文献

Background: Atopic dermatitis (AD), the most common inflammatory skin disorder, carries a significant public health burden. Many patients with moderate-to-severe AD are unable to achieve adequate disease control with topical treatment and require treatment with oral immunosuppressants or monoclonal antibody injections. A continued unmet need for a safe, effective and easy-to-use oral drug exists. AD has a complex pathophysiology, including adaptive- and innate-dependent mechanisms, some of which involve Bruton tyrosine kinase (BTK). Rilzabrutinib is an oral, selective and reversible covalent BTK inhibitor.

Objectives: To assess the efficacy and safety of rilzabrutinib in patients with moderate-to-severe AD and inadequate response or intolerance to topical corticosteroids.

Methods: Eligible adults were enrolled in two staggered dose-regimen cohorts: 800 mg daily (400 mg twice daily) or 1200 mg daily (400 mg three times daily) and randomized 3 : 2 to receive rilzabrutinib or placebo for 16 weeks. The primary efficacy endpoint was percentage change in Eczema Area and Severity Index (EASI) score from baseline to week 16. Key secondary endpoints included the proportion of participants at week 16 achieving an Investigator's Global Assessment score of 0 or 1, achieving EASI 75 and with a reduction in the weekly average of the daily Peak Pruritus Numerical Rating Scale (PP-NRS) of ≥ 4 from baseline. Safety was measured by recording adverse events (AEs).

Results: The primary endpoint did not reach statistical significance [least squares mean difference vs. placebo: 800 mg -6.3% (P = 0.62); 1200 mg -3.9% (P = 0.67)]. The key secondary endpoints also did not demonstrate significant improvements with rilzabrutinib vs. placebo. However, a rapid improvement in absolute and relative change in weekly average of the daily PP-NRS was demonstrated with rilzabrutinib. Rilzabrutinib was well tolerated. Treatment-emergent AEs (TEAEs) were mostly mild, with a low incidence of serious AEs. TEAEs occurring at a higher frequency with rilzabrutinib than with placebo included nausea and diarrhoea. AEs associated with previous generations of BTK inhibitors were not seen with rilzabrutinib.

Conclusions: This study did not meet its primary endpoint. However, consistent results favouring rilzabrutinib with regard to itch response were observed. These findings also highlight the acceptable safety profile of rilzabrutinib vs. the AEs associated with other BTK inhibitors.

Background: The Harmonising Outcome Measures for Eczema (HOME) initiative has established a core outcome set for atopic dermatitis (AD) clinical trials, including four core outcome domains: clinician-reported signs, patient-reported symptoms, eczema control and quality of life. For eczema control, the Atopic Dermatitis Control Tool (ADCT) and the Recap of Atopic Eczema (RECAP) were chosen through consensus methods as equivalent instruments.

Objectives: This study aimed to develop equations to map scores between ADCT and RECAP to facilitate inter-measurement comparison and data synthesis.

Methods: Patients with AD completed the HOME core outcome set of instruments, including ADCT, RECAP, Dermatology Life Quality Index series, Peak Pruritus Numerical Rating Scale and Patient-Oriented Eczema Measure, during routine clinic visits. Clinicians assessed disease severity using the Investigator Global Assessment x Body Surface Area measure.

Results: Among 50 participants, ADCT and RECAP were strongly correlated (Pearson's correlation coefficient, r = 0.970). Four mapping models were evaluated: simple linear regression (SLR), SLR without intercept, square root transformation (SRT) and SRT without intercept. While the SRT no intercept model had the lowest root mean square error, it produced nonlinear confidence intervals and risked overfitting. The SLR no intercept model, with high predictive accuracy (R2 = 0.971) and interpretability, was selected as the primary approach. Two equations were derived to convert scores between ADCT and RECAP, enabling standardized comparisons.

Conclusions: This study provides two equations for mapping between ADCT and RECAP, strengthening the HOME outcome measurement set and synthesizing the two measures for clinical and research purposes. Validation with larger, independent cohorts is warranted to confirm these findings.

Background: Pemphigus vulgaris (PV) is an autoimmune blistering skin disease caused by impaired desmosome adhesion. Altered signalling pathways and direct inhibition of desmoglein (Dsg) binding contribute to loss of cell adhesion, but the sequence of these events is still a matter of debate.

Objectives: To characterize the early sequence of events following autoantibody binding to Dsg3 in the pathogenesis of pemphigus.

Methods: We established stimulated emission depletion imaging in combination with atomic force microscopy single-molecule force measurements to elucidate the primary events following autoantibody binding. Therefore, we measured the Dsg3 binding properties on individual desmosomes and used Triton X-100 fractionation, Western blotting, immunofluorescence and keratinocyte dissociation assays.

Results: We found that the primary loss of cell adhesion and Dsg3 binding occurs in human keratinocytes as soon as autoantibodies are detectable in desmosomes, which is as early as 5 min for the monoclonal anti-Dsg3 antibody AK23 and 15 min after the addition of PV IgG autoantibodies from patients. Activation of p38 mitogen-activated protein kinase (MAPK) - a central signalling mechanism in PV - was significant after 30 min but not detectable in desmosomes after 5 min of AK23 incubation. Nevertheless, p38 MAPK was required for the loss of cytoskeletal anchorage of Dsg3 molecules in desmosomes and inhibition of p38 MAPK-blunted loss of Dsg3 binding and cell adhesion.

Conclusions: The results show that autoantibody-induced direct inhibition of Dsg3 binding precedes p38 MAPK-mediated cytoskeletal uncoupling at desmosomes. Thus, the signalling function of Dsg3 in activating p38 MAPK is triggered by the loss of transinteraction, which is the primary target point for therapeutic strategies to stabilize keratinocyte adhesion in PV.

More than 50 palmoplantar epidermal differentiation disorders (pEDDs) have been reported in the literature. Various descriptors have been used to name these conditions, including clinical features often designated as acronyms or evocative terms, and names of clinicians and of geographical locations. Not only has this nomenclature been criticized for its lack of methodological consistency, but it has also progressively lost its clinical relevance. Indeed, the advent of a wide range of pathogenesis-targeting therapeutic solutions for these disorders has raised the need for a novel classification of pEDDs, based on their causative genetic defects, to provide clinicians with genuine therapeutic guidance. Here, we present a novel classification scheme for pEDDs and its application in the form of a practical algorithm for the rapid diagnosis of pEDDs.