Psoriasis in Skin of Color: Insights into the Epidemiology, Clinical Presentation, Genetics, Quality-of-Life Impact, and Treatment of Psoriasis in Non-White Racial/Ethnic Groups

Psoriatic Disease in the US Latino Population: A Comprehensive Review

Current evidence suggests that there are notable differences in the severity of psoriasis between racial and ethnic groups. While the US Latino population is growing rapidly, there is little research on the various factors impacting disease severity in this minority population. This review evaluates the current evidence on psoriasis in Latinos within the US. Psoriasis affects the US Latino population at a lower prevalence, with more severe disease and a greater quality-of-life impact than their White counterparts. In addition, Latinos with psoriasis experience higher rates of comorbidities, such as depression, obesity, and diabetes compared with Whites. There is evidence showing non-inferior or better response to systemic treatments, such as etanercept, secukinumab, and brodalumab, in this population. The combination of barriers to care and lack of involvement in research limit the current understanding of the mechanisms responsible for the pathologic outcomes and the environmental and social disparities observed. Future studies that reflect the growing proportion of minorities in the US may help close these knowledge gaps and improve care.

Phototherapy in Skin of Color

Phototherapy in skin of color requires special consideration. Pigmented skin is an efficient ultraviolet filter. Hence, higher doses of ultraviolet radiation are generally more effective and well tolerated in skin of color. An objective and practical system has not yet been established to determine optimal phototherapy dosing in skin of color. The authors recommend obtaining a detailed history of each individual patient's response to sun exposure before prescribing a phototherapy dosing regimen. In addition, providers should consider the role of socioeconomic factors and their impact on phototherapy-related outcomes, including barriers to access and compliance.

Interferon Kappa Is Up-Regulated in Psoriasis and It Up-Regulates Psoriasis-Associated Cytokines in vivo

Purpose

There is increased type I interferon signature in psoriasis patients. Interferon-kappa (IFN-κ) is a member of type I interferon family that is constitutively expressed by keratinocytes. In this study, we investigate whether IFN-κ is involved in psoriasis etiology.

Patients and methods

Twenty healthy individuals, 20 psoriasis vulgaris patients and 10 atopic dermatitis (AD) were included for this study. Immunohistochemistry staining, normal human epidermal keratinocytes (NHEK) culture, Ca₂Cl-induced differentiation, quantitative reverse transcription (qRT-PCR), ELISA and murine experiments were performed.

Results

We found IFN-κ protein expression was extremely low in the epidermis of normal skin, but it was significantly increased in the suprabasal layers of epidermal keratinocytes in psoriatic skin lesions. However, its expression in the skin lesions of AD was similar to normal skin. Additionally, IFN-κ protein was detected in sera from psoriasis patients, but not in sera from normal subjects and AD. We further investigated the regulation of IFNk gene expression in NHEK. We found that IFNk was significantly induced by types of nucleic acid pathogen recognition receptor (PRR) agonists in NHEK. While its expression was significantly induced by itself and IFN-γ, it was inhibited by type 2 immunity cytokines IL4 and IL13; other inflammatory cytokines including IL1 super-family members and IL17A did not alter its expression. Addition of recombinant IFN-κ did not affect keratinocytes differentiation. Using the murine experimental model, we demonstrated that subcutaneous administration of recombinant IFN-κ did not increase skin thickness, but significantly increased the transcription of TNFA and IL17A in mice skin.

Conclusion

Increased IFN-κ in psoriasis may be caused by injured cells-released nucleic acids, increased IFN-γ and self-activation. Its enhancement may contribute to the etiology of the disease by enhancing TNFA and IL17A gene expression.

How do we treat psoriasis patients with hepatitis C infections in real-world situations? A retrospective analysis of 34 patients

BACKGROUND

There is still relatively limited data on psoriasis and hepatitis C virus (HCV) infections.

OBJECTIVE

This study investigated the clinical characteristics and treatment of psoriasis patients with HCV infections in real-world practice.

METHODS

Medical records of all psoriasis patients with HCV infections who attended the outpatient clinic at Siriraj Hospital over a 10-year period were retrospectively reviewed.

RESULTS

Of 34 patients, 26 and 8 patients were men and women, respectively with a mean age of 57.0 ± 8.7 (range, 42.2-77.2) years. The median age of psoriasis onset was 42.7 ± 12.7 (range, 8-67.25) years. With a median follow-up period of 13.6 years, cirrhosis and hepatocellular carcinoma were found in 67.6% and 29.4% of the patients, respectively. The interferon used for HCV treatment exacerbated the psoriasis in 20% of those patients. Conventional treatments and anti-tumor necrosis factors (anti-TNFs) were used in strict collaboration with hepatologists. No patients experienced a worsening of their HCV infection.

CONCLUSION

Despite a limited number of patients, a male predominance and late-onset psoriasis were frequently observed. Although, interferon therapy for HCV can exacerbate psoriasis, it is not contraindicated. All conventional treatments and anti-TNFs can be used, provided that there is strict collaboration with hepatologists.

Efficacy and Safety of Brodalumab in Patients with Moderate-to-Severe Plaque Psoriasis and Skin of Color: Results from the Pooled AMAGINE-2/-3 Randomized Trials

BACKGROUND

Data on treatment outcomes in patients with psoriasis who have skin of color are limited. Brodalumab has shown efficacy in patients with moderate-to-severe plaque psoriasis.

OBJECTIVE

Our objective was to evaluate the efficacy, safety, and health-related quality of life associated with brodalumab in patients with skin of color participating in two phase III, multicenter, randomized, double-blind, placebo- and active comparator-controlled studies (AMAGINE-2/-3).

METHODS

Patients were self-categorized into racial subgroups (black, Asian, or white) or the non-mutually exclusive ethnic subgroup Hispanic/Latino. Patients were randomized to receive brodalumab 210 mg every 2 weeks (Q2W) or ustekinumab (45 mg in patients weighing ≤ 100 kg and 90 mg in patients weighing > 100 kg) for 52 weeks. Skin clearance was monitored using the Psoriasis Area and Severity Index (PASI) and Static Physician's Global Assessment (sPGA). Treatment-emergent adverse events (TEAEs) were summarized by treatment and racial and ethnic subgroup. Health-related quality of life was assessed using the Dermatology Life Quality Index (DLQI).

RESULTS

During the 12-week induction phase, 613 patients received ustekinumab (black, n = 20; Asian, n = 24; white, n = 551; Hispanic/Latino, n = 68) and 1236 patients received brodalumab 210 mg Q2W (black, n = 36; Asian, n = 39; white, n = 1116; Hispanic/Latino, n = 132). At week 52, a total of 590 patients received continuous ustekinumab (black, n = 19; Asian, n = 23; white, n = 532; Hispanic/Latino, n = 64) and 339 patients were re-randomized to continue receiving brodalumab 210 mg Q2W (black, n = 10; Asian, n = 7; white, n = 308; Hispanic/Latino, n = 40). Among patients who received brodalumab 210 mg Q2W, skin clearance response rates were similar across racial and ethnic subgroups at week 12 and week 52; rates of 75%, 90%, and 100% improvement in PASI from baseline were also higher, as was sPGA score ≤ 1, than in patients who received ustekinumab across all racial and ethnic subgroups. Rates of TEAEs and ≥ 5-point improvement in DLQI score were similar across racial and ethnic subgroups.

CONCLUSIONS

Brodalumab 210 mg Q2W is well tolerated and efficacious across diverse racial and ethnic subgroups in patients with psoriasis, including black, Asian, white, and Hispanic/Latino patients.

TRIAL REGISTRY

ClinicalTrials.gov identifier NCT01708603 (AMAGINE-2); NCT01708629 (AMAGINE-3).

Transcription Factor Retinoid-Related Orphan Receptor γt: A Promising Target for the Treatment of Psoriasis

Psoriasis, which is a common chronic inflammatory skin disease, endangers human health and brings about a major economic burden worldwide. To date, treatments for psoriasis remain unsatisfied because of their clinical limitations and various side effects. Thus, developing a safer and more effective therapy for psoriasis is compelling. Previous studies have explicitly shown that psoriasis is an autoimmune disease that is predominantly mediated by T helper 17 (Th17) cells, which express high levels of interleukin-17 (IL-17) in response to interleukin-23 (IL-23). The discovery of the IL-23–Th17–IL-17 axis in the development of psoriasis has led to the paradigm shift of understanding pathogenesis of psoriasis. Although anti-IL-17 antibodies show marked clinical efficacy in treating psoriasis, compared with antibodies targeting IL-17A or IL-17R alone, targeting Th17 cells themselves may have a maximal benefit by affecting multiple proinflammatory cytokines, including IL-17A, IL-17F, IL-22, and granulocyte-macrophage colony-stimulating factor, which likely act synergistically to drive skin inflammation in psoriasis. In this review, we mainly focus on the critical role of Th17 cells in the pathogenesis of psoriasis. Especially, we explore the small molecules that target retinoid-related orphan receptor γt (RORγt), a vital transcription factor for Th17 cells. Given that RORγt is the lineage-defining transcription factor for Th17 cell differentiation, targeting RORγt via small molecular inverse agonists may be a promising strategy for the treatment of Th17-mediated psoriasis.

Are quantitative histopathologic criteria capable of differentiating psoriasis from chronic dermatitis?

Background

There are overlapping features in histopathologic characteristics of psoriasis and chronic dermatitis, which sometimes make the correct diagnosis difficult.

Objective

The aim of this study was to compare the histopathologic diagnostic features of psoriasis with chronic dermatitis quantitatively.

Patients and methods

In this study, 30 patients with psoriasis and 30 patients with chronic dermatitis were included. Diagnosis of psoriasis or chronic dermatitis was based on clinicopathologic correlation. Photos of histopathologic slides were provided by LABOMED Digital Camera and LABOMED Microscope. Width and length of rete ridges, minimal thickness of suprapapillary plates, thickness of epidermis, thickness of hyperkeratotic layer, and minimal thickness of granular layer were determined using Pixel Pro software on micrometer scale.

Results

Suprapapillary plates and granular layer were significantly thicker in patients with chronic dermatitis compared with patients with psoriasis. The rete ridges were longer and wider, the epidermis was thicker, and the parakeratotic layer was also thicker in patients with psoriasis compared with patients with chronic dermatitis, and the difference between these corresponding parameters in the two groups was statistically significant except for thickness of parakeratotic layer. Moreover, the mean ratio of minimal suprapapillary plate’s thickness to epidermal thickness and the mean ratio of minimal granular layer’s thickness to parakeratotic layer’s thickness were significantly higher in patients with chronic dermatitis compared with those with psoriasis.

Conclusion

Despite overlapping histopathologic features in psoriasis and chronic dermatitis, quantitative histopathologic criteria might be valuable for differentiation of these two conditions. Ratios of minimal suprapapillary plate’s thickness to epidermal thickness and minimal granular layer’s thickness to parakeratotic layer’s thickness can be particularly helpful in this regard.