Duration of remission period of narrowband ultraviolet B therapy on psoriasis vulgaris

Home- vs Office-Based Narrowband UV-B Phototherapy for Patients With Psoriasis: The LITE Randomized Clinical Trial

Importance

Office-based phototherapy is cost-effective for psoriasis but difficult to access. Home-based phototherapy is patient preferred but has limited clinical data, particularly in patients with darker skin.

Objective

To compare the effectiveness of home- vs office-based narrowband UV-B phototherapy for psoriasis.

Design, Setting, and Participants

The Light Treatment Effectiveness study was an investigator-initiated, pragmatic, open-label, parallel-group, multicenter, noninferiority randomized clinical trial embedded in routine care at 42 academic and private clinical dermatology practices in the US. Enrollment occurred from March 1, 2019, to December 4, 2023, with follow-up through June 2024. Participants were 12 years and older with plaque or guttate psoriasis who were candidates for home- and office-based phototherapy.

Interventions

Participants were randomized to receive a home narrowband UV-B machine with guided mode dosimetry or routine care with office-based narrowband UV-B for 12 weeks, followed by an additional 12-week observation period.

Main Outcomes and Measures

The coprimary effectiveness outcomes were Physician Global Assessment (PGA) dichotomized as clear/almost clear skin (score of ≤1) at the end of the intervention period and Dermatology Life Quality Index (DLQI) score of 5 or lower (no to small effect on quality of life) at week 12.

Results

Of 783 patients enrolled (mean [SD] age, 48.0 [15.5] years; 376 [48.0%] female), 393 received home-based phototherapy and 390 received office-based phototherapy, with 350 (44.7%) having skin phototype (SPT) I/II, 350 (44.7%) having SPT III/IV, and 83 (10.6%) having SPT V/VI. A total of 93 patients (11.9%) were receiving systemic treatment. At baseline, mean (SD) PGA was 2.7 (0.8) and DLQI was 12.2 (7.2). At week 12, 129 patients (32.8%) receiving home-based phototherapy and 100 patients (25.6%) receiving office-based phototherapy achieved clear/almost clear skin, and 206 (52.4%) and 131 (33.6%) achieved DLQI of 5 or lower, respectively. Home-based phototherapy was noninferior to office-based phototherapy for PGA and DLQI in the overall population and across all SPTs. Home-based phototherapy, compared to office-based phototherapy, was associated with better treatment adherence (202 patients [51.4%] vs 62 patients [15.9%]; P < .001), lower burden of indirect costs to patients, and more episodes of persistent erythema (466 of 7957 treatments [5.9%] vs 46 of 3934 treatments [1.2%]; P < .001). Both treatments were well tolerated with no discontinuations due to adverse events.

Conclusions and Relevance

In this randomized clinical trial, home-based phototherapy was as effective as office-based phototherapy for plaque or guttate psoriasis in everyday clinical practice and had less burden to patients.

Trial Registration

ClinicalTrials.gov Identifier: NCT03726489.

Definitions of Remission in Psoriasis: A Systematic Literature Review from the National Psoriasis Foundation

Psoriasis studies increasingly employ outcomes that indicate complete disease resolution, yet remission and cure are poorly defined for psoriasis. We conducted a systematic literature review to identify definitions of psoriasis remission and cure reported in the literature. Medline, EMBASE, and The Cochrane Central Register of Controlled Trials databases were searched on July 22, 2020 for full-text studies providing definitions for psoriasis remission/cure. Definitions were analyzed descriptively for endpoint, time-frame, on/off treatment, patient-reported outcomes, and disease domains. We identified 106 studies that provided 41 unique remission definitions. Most definitions included endpoints based on Psoriasis Area and Severity Index (PASI), such as PASI75 (n=16 studies), PASI90 (n=10), PASI100 (n=10), and PASI of 0 (n=3), and descriptive endpoints related to 'skin clearance' (n=18). Few definitions specified time-frame, on/off treatment or other psoriasis-related disease domains. One small consensus-initiative defined drug-free remission for plaque psoriasis by BSA of 0 without any therapy for at least 12 months. While there is no cure for psoriasis, seven studies defined psoriasis cure using similar endpoints to those used to define remission. We identified a variety of definitions of psoriasis remission. These results will inform the development of consensus-based definitions for psoriasis remission to support efforts to improve research and clinical outcomes.

Therapeutic wavelengths of ultraviolet B radiation activate apoptotic, circadian rhythm, redox signalling and key canonical pathways in psoriatic epidermis

Ultraviolet B radiation (UVB) exerts pleiotropic effects on human skin. DNA damage response and repair pathways are activated by UVB; if damage cannot be repaired, apoptosis ensues. Although cumulative UVB exposure predisposes to skin cancer, UVB phototherapy is widely used as an effective treatment for psoriasis. Previous studies defined the therapeutic action spectrum of UVB and showed that psoriasis is resistant to apoptosis. This study aimed to investigate early molecular responses within psoriasis plaques following irradiation with single equi-erythemogenic doses of clinically-effective (311 nm, narrow-band) compared to clinically-ineffective (290 nm) UVB. Forty-eight micro-dissected epidermal samples from 20 psoriatic patients were analyzed using microarrays. Our bioinformatic analysis compared gene expression between 311 nm irradiated, 290 nm irradiated and control psoriasis epidermis to specifically identify 311 nm UVB differentially expressed genes (DEGs) and their upstream regulatory pathways. Key DEGs and pathways were validated by immunohistochemical analysis. There was a dynamic induction and repression of 311 nm UVB DEGs between 6 h and 18 h, only a limited number of DEGs maintained their designated expression status between time-points. Key disease and function pathways included apoptosis, cell death, cell migration and leucocyte chemotaxis. DNA damage response pathways, NRF2-mediated oxidative stress response and P53 signalling were key nodes, interconnecting apoptosis and cell cycle arrest. Interferon signalling, dendritic cell maturation, granulocyte adhesion and atherosclerotic pathways were also differentially regulated. Consistent with these findings, top transcriptional regulators of 311 nm UVB DEGs related to: a) apoptosis, DNA damage response and cell cycle control; b) innate/acquired immune regulation and inflammation; c) hypoxia/redox response and angiogenesis; d) circadian rhythmicity; f) EGR/AP1 signalling and keratinocyte differentiation; and g) mitochondrial biogenesis. This research provides important insights into the molecular targets of 311 nm UVB, underscoring key roles for apoptosis and cell death. These and the other key pathways delineated may be central to the therapeutic effects of 311 nm in psoriasis.

Anti-IL-17A and IL-23p19 antibodies but not anti-TNFα antibody induce expansion of regulatory T cells and restoration of their suppressive function in imiquimod-induced psoriasiform dermatitis

BACKGROUND

Psoriasis is a chronic inflammatory skin disease. Anti-TNFα, IL-17A and IL-23p19 antibodies are effective for psoriasis. However, the contribution of regulatory T cells (Treg) in their effectiveness remains to be elucidated.

OBJECTIVE

We investigated the effects of TNFα, IL-17A and IL-23p19 inhibition on Tregs in imiquimod-induced psoriasiform dermatitis.

METHODS

Psoriasiform dermatitis was induced by imiquimod application on murine shaved back skin for six days. Mice were treated with anti-TNFα, IL-17A or IL-23p19 monoclonal antibodies every other day from one day before imiquimod application.

RESULTS

Administration of anti-TNFα, IL-17A or IL-23p19 antibodies improved the clinical score and downregulated Th17-related cytokines and chemokines, while IL-23p19 antibodies upregulated IL-10 mRNA expression. Anti-IL-17A or IL-23p19 antibody-treated imiquimod-applied mice showed a significant increase in the number of Foxp3⁺ IL-10⁺ Tregs. Recipient mice adoptively transferred with Tregs derived from donor mice treated with antibodies demonstrated clinical and pathological improvement in imiquimod-induced psoriasiform dermatitis. Anti-IL-17A or IL-23p19 antibody-induced Tregs significantly increased the number of Foxp3⁺ cells and IL-10 expression in imiquimod-induced psoriasiform dermatitis in recipient mice but anti-TNFα antibody-induced Tregs did not.

CONCLUSION

Anti-IL-17A or IL-23p19 antibody inhibits the IL-17/IL-23 signaling pathway, and induces expansion of Tregs and their suppressive capacity in imiquimod-induced psoriasiform dermatitis.

Remission period in psoriasis after multiple cycles of narrowband ultraviolet B phototherapy

The aim of this study was to investigate the duration of remission periods in psoriasis after narrowband ultraviolet B (NB-UVB) phototherapy, especially during multiple cycles of treatment. We analyzed 63 patients (101 cases) demonstrating marked improvement after NB-UVB phototherapy. The remission period was defined as the duration of time from the end of phototherapy until treatment using either phototherapy or systemic treatments was required again. It was found that an age of 60 years or older, history of systemic therapy within 6 months and three or more phototherapy cycles were significantly associated with shorter remission periods. Furthermore, multivariate analysis confirmed that three or more phototherapy cycles (odds ratio [OR], 4.0; 95% confidence interval [CI], 1.73-9.33; P = 0.001) and a history of systemic therapy (OR, 2.2; 95% CI, 1.27-3.95; P = 0.005) were independently associated with the shorter remission period. In conclusion, when planning NB-UVB phototherapy for psoriatic patients who have undergone multiple phototherapy cycles, clinicians should consider the possibility of shorter remission periods.