Guselkumab Treatment Outcomes and Persistence in a Nationwide Real-world Cohort of Patients with Plaque Psoriasis.

Guselkumab treatment outcomes and persistence were assessed in a real-world cohort of Finnish patients with difficult-to-treat plaque psoriasis over a median follow-up of 1 year. Data on 181 patients who initiated guselkumab at the 15 study centres were collected retrospectively from the patient charts. Prior exposure to biologic therapies was common, with 56% and 35% having used at least 1 and 2 biologics, respectively. Median guselkumab treatment duration was 11 months with 21 patients (12%) discontinuing treatment during follow-up. Of 85 patients with a follow-up duration of at least 1 year, 73 (86%) were still on guselkumab at 1 year. Significant improvements during follow-up were seen in the absolute Psoriasis Area and Severity Index (PASI) scores with 32 patients (80%) having absolute PASI ≤ 2 after a 9-14-month treatment. Guselkumab treatment was effective and treatment persistence was high in the nationwide Finnish real-life setting.

Immediate Wheal Reactivity to Autologous Sweat in Atopic Dermatitis Is Associated with Clinical Severity, Serum Total and Specific IgE and Sweat Tryptase Activity.

BACKGROUND: Sweating can worsen atopic dermatitis (AD). The purpose of this work was to study the associations between reactivity to autologous sweat and the clinical severity of AD as well as investigate the possible wheal-inducing factors of sweat. METHODS: Intracutaneous skin tests with autologous sweat were performed on 50 AD patients and 24 control subjects. In skin biopsies, tryptase and PAR-2 were enzyme and immunohistochemically stained. The associations between skin test reactivity and sweat histamine concentration, tryptase or chymase activity levels, tryptase or PAR-2 expression and AD clinical severity or IgE levels were investigated. RESULTS: The wheal reactions in the intracutaneous tests with autologous sweat were positive, weakly positive and negative in 38, 34 and 28% of the AD patients, respectively, and in 4, 46 and 50% of the healthy controls, respectively (p = 0.008). In AD, the wheal reaction was associated significantly with clinical severity, serum total and specific IgE levels and sweat tryptase activity, but not with sweat histamine and chymase. In nonlesional AD skin, the percentage of PAR-2+ mast cells (MCs) or the number of tryptase+ MCs did not differ significantly between the intracutaneous test reactivity groups. CONCLUSION: Reactivity to autologous sweat correlates with the clinical severity of AD, and tryptase may be one of the factors involved in the sweat-induced wheal.

Epidermal Expression of Filaggrin/Profilaggrin Is Decreased in Atopic Dermatitis: Reverse Association With Mast Cell Tryptase and IL-6 but Not With Clinical Severity.

BACKGROUND: A decrease in filaggrin expression contributes to the pathogenesis of atopic dermatitis (AD) and can be modified by inflammatory factors. OBJECTIVES: The aim of this study was to determine the correlation of (pro)filaggrin (filaggrin and profilaggrin) expression with clinical severity in AD and with mast cell (MC) tryptase, chymase, and IL-6. METHODS: Punch biopsies were collected from 17 patients with moderate-to-severe AD and from 10 psoriatic patients. Atopic dermatitis severity was measured using different clinical parameters. (Pro)filaggrin, MC tryptase, chymase, and IL-6 were stained using immunohistochemical, enzymehistochemical, and sequential double-staining methods. RESULTS: (Pro)filaggrin expression was lower in the lesional than in the nonlesional granular layer in AD and was correlated negatively with itch severity but not with other severity parameters. (Pro)filaggrin expression was also decreased in the psoriatic lesions. In AD, (pro)filaggrin expression correlated negatively with the number of tryptase MCs in the nonlesional granular layer and with IL-6 MCs in both the nonlesional and lesional granular layers. CONCLUSION: (Pro)filaggrin expression is decreased in AD and is reversely associated with MC tryptase and IL-6. However, it does not associate with disease severity, and it was also decreased in psoriasis.

Decrease in chymase activity is associated with increase in IL-6 expression in mast cells in atopic dermatitis.

Mast cell chymase and interleukin (IL)-6 can be involved in atopic dermatitis and chymase can degrade IL-6. Our aim was therefore to study the expression of mast cell chymase and IL-6 in atopic skin using enzyme- and immunohistochemistry and to analyse their interaction in vitro. Chymase activity was significantly reduced in mast cells in skin lesions whereas the percentage of IL-6(+) mast cells was increased. Low recombinant human (rh)-chymase concentration (10-100 ng/ml) stimulated and higher concentration (1,000 ng/ml) inhibited the proliferation of T cells and peripheral blood mononuclear cells. Rh-IL-6 inhibited T-cell proliferation, and even inhibited the proliferation induced by rh-chymase. Pretreatment of rh-IL-6 with a high rh-chymase concentration prevented the IL-6-induced inhibition in T-cell proliferation. The results suggest that reduction in chymase activity can give rise to increased cellular effects of mast cell IL-6 and that chymase and IL-6 can modify each other's effects.