Psoriasis in Swedish conscripts: time trend and association with T-helper 2-mediated disorders

Association between allergic diseases and both psoriasis and psoriatic arthritis: a bidirectional 2-sample Mendelian randomization study

Background An increasing body of observational studies has indicated a potential link between allergic diseases, namely atopic dermatitis (AD), allergic rhinitis (AR), allergic asthma (AA), and psoriasis (PSO) as well as psoriatic arthritis (PSA). However, the presence and causal direction of this association remain uncertain. Methods We conducted two-sample Mendelian randomization (TSMR) analyses utilizing summary statistics derived from genome-wide association studies (GWAS) consortia. The summary statistics were obtained from a substantial participant cohort, consisting of 116,000 individuals (21,000 AD cases and 95,000 controls), 462,933 individuals (26,107 AR cases and 436,826 controls), and 140,308 individuals (4859 AA cases and 135,449 controls). The summary statistics for PSO (9267 cases and 360,471 controls) and PSA (3186 cases and 240,862 controls) were sourced from the FinnGen database. The primary analytical approach employed inverse variance weighting (IVW) as the main method within TSMR. We validated our findings through a series of sensitivity analyses. Furthermore, we performed reverse TSMR analyses to evaluate the potential presence of reverse causality. Results Our investigation revealed a potential protective effect of AD against both PSO (OR = 0.922, 95% CI = 0.863-0.984, p = 0.015)and PSA(OR = 0.915, 95% CI = 0.843-0.993, p = 0.033). Moreover, employing inverse MR analysis, we obtained compelling evidence supporting the protective role of PSO in preventing AD (OR = 0.891, 95% CI = 0.829-0.958, p = 0.002), as well as AR (OR = 0.998, 95% CI = 0.996-0.999, p = 0.008), these associations remained statistically significant even after Bonferroni correction was applied to account for multiple comparisons. Furthermore, our findings did not reveal any substantial causal relationship between AA and either PSO or PSA. Conclusion Our study provides compelling evidence that PSO significantly confers protection against both AD and AR, while AD is likely to act as a protective factor for both PSO and PSA. Despite previous studies suggesting an association between allergic diseases and the incidence of PSO and PSA, our findings do not support this claim. To obtain more accurate and reliable conclusions regarding the causal mechanisms involved, larger sample sizes in randomized controlled trials or MR studies are warranted.

Can atopic eczema and psoriasis coexist? A systematic review and meta-analysis

Importance

Previous studies report both coexistence and mutual exclusivity of atopic eczema (AE) and psoriasis, but these have not been appraised systematically. Knowledge of such disease association throws light on disease mechanisms and may influence therapeutic choices.

Objective

To summarise evidence for AE and psoriasis occurring in the same person at the same point in time. Planned primary outcome was the incidence, prevalence or risk of psoriasis or eczema.

Methods

Ovid MEDLINE and Ovid Embase were searched from inception to 1st February 2020. The search strategy was built around the key terms ‘atopic eczema’, ‘psoriasis’ and ‘co‐existence’. Observational studies (cohort, case‐control, cross‐sectional and case‐series) with a minimum of 10 consecutive patients were included. There were no restrictions on participants, geography or language. Studies were selected, data extracted and critically appraised by two independent reviewers. Data were extracted on the method of diagnosis: health professional (dermatologist, criteria, other), self‐reported, not specified. Study quality was assessed using validated Joanna Brigg's Institute critical appraisal tools. A random‐effects model was used to combine studies. The effect of study quality on the pooled estimate was investigated using stratification. Heterogeneity was explored by subgroup analysis.

Results

This review included 31 studies and 20 523 individuals with psoriasis and 1 405 911 with AE. Eight studies reported the prevalence of AE in those with psoriasis and values ranged from 0.17% to 20%: the pooled prevalence was 2% (95% confidence interval [CI]: 1, 3). Seven studies reported the prevalence of psoriasis in those with AE and values ranged from 0.3% to 12.6%; the pooled prevalence was 2% (95% CI: 1, 3). Ten studies were assessed as low risk of bias. Geographical area, method of diagnosis, setting and whether the assessment of diagnosis was blinded, partly contributed to the heterogeneity.

Conclusions

This review provides some evidence for the coexistence of AE and psoriasis. Clinicians should be aware of coexistence at diagnosis, when selecting therapies and when reviewing poor response to treatment.

Psoriatic T cells recognize neolipid antigens generated by mast cell phospholipase delivered by exosomes and presented by CD1a

Psoriasis is a chronic inflammatory skin disease associated with a T helper 17 response. Yet, it has proved challenging to identify relevant peptide-based T cell antigens. Antigen-presenting Langerhans cells show a differential migration phenotype in psoriatic lesions and express constitutively high levels of CD1a, which presents lipid antigens to T cells. In addition, phospholipase A2 (PLA2) is highly expressed in psoriatic lesions and is known to generate neolipid skin antigens for recognition by CD1a-reactive T cells. In this study, we observed expression of a cytoplasmic PLA2 (PLA2G4D) in psoriatic mast cells but, unexpectedly, also found PLA2G4D activity to be extracellular. This was explained by IFN-α-induced mast cell release of exosomes, which transferred cytoplasmic PLA2 activity to neighboring CD1a-expressing cells. This led to the generation of neolipid antigens and subsequent recognition by lipid-specific CD1a-reactive T cells inducing production of IL-22 and IL-17A. Circulating and skin-derived T cells from patients with psoriasis showed elevated PLA2G4D responsiveness compared with healthy controls. Overall, these data present an alternative model of psoriasis pathogenesis in which lipid-specific CD1a-reactive T cells contribute to psoriatic inflammation. The findings suggest that PLA2 inhibition or CD1a blockade may have therapeutic potential for psoriasis.

Association between psoriasis and asthma: a population-based retrospective cohort analysis

BACKGROUND

Both psoriasis and asthma are chronic immune-mediated inflammatory diseases.

OBJECTIVES

To evaluate the risk of developing asthma in patients with psoriasis compared with controls.

METHODS

This cohort study was conducted using data from the Taiwan National Health Insurance Research Database. Patients with psoriasis (n = 10,288) and matched comparison patients without psoriasis (n = 41,152) were evaluated. A Cox proportional hazard regression analysis was used to determine the risk of asthma in patients with and without psoriasis.

RESULTS

The risk of asthma was 1·38-fold higher [95% confidence interval (CI) 1·23-1·54] in the cohort with psoriasis than in the reference cohort, after adjusting for age, sex and comorbidities. The incidence of asthma in men and women with psoriasis exhibited nonsignificant differences. Among all patients aged > 50 years, psoriasis was associated with a higher risk of asthma compared with not having psoriasis [adjusted hazard ratio (HR) 1·49; 95% CI 1·18-1·88 (in patients aged 50-64 years); adjusted HR 1·63; 95% CI 1·34-1·99 (in patients aged > 65 years)].

CONCLUSIONS

Our results indicate that patients with psoriasis are associated with a increased risk of developing asthma.

Demography, baseline disease characteristics and treatment history of patients with psoriasis enrolled in a multicentre, prospective, disease-based registry (PSOLAR)

BACKGROUND

Psoriasis is associated with several comorbidities and behavioural risk factors.

OBJECTIVES

To evaluate demographic and disease characteristics in patients enrolled in the Psoriasis Longitudinal Assessment and Registry (PSOLAR).

METHODS

PSOLAR is a global, prospective, longitudinal, disease-based registry that includes a postmarketing commitment to evaluate safety in patients with psoriasis. Enrolled patients had to be receiving, or be eligible to receive, conventional systemic or biological agents. Demographic/disease characteristics, medical histories, lifestyle risk factors and previous treatments are collected at enrolment. Efficacy and safety data are collected every 6 months for 8 years, and data are extracted annually. Selected parameters are evaluated by age quartile using post hoc analyses.

RESULTS

As of 23 August 2012, 11 900 patients were enrolled at 301 sites in North America, Europe and Latin America. Over half of the PSOLAR population (54·7%) is male, with a mean age of 48·6 years and mean body mass index of 30·9 kg m(-2) at enrolment. Mean duration of disease at enrolment was 17·5 years, and mean Physician's Global Assessment score was 2·0. Psoriatic arthritis (35·5%) and cardiovascular diseases (38·2%) were highly prevalent. Diabetes mellitus type II was reported in 11·4% of patients. Depression and anxiety were noted in 14·7% and 11·1% of patients, respectively; 79·0% reported any alcohol use and 56·7% reported smoking or a history of smoking. The occurrence of most comorbidities, including cardiovascular disease and risk factors, increased with age.

CONCLUSIONS

In the PSOLAR population, multiple and age-appropriate comorbidities are associated with psoriasis and may affect the selection of psoriasis treatments.

The "T" in trauma: the helper T-cell response and the role of immunomodulation in trauma and burn patients

BACKGROUND

The immune system undergoes numerous changes after traumatic and burn injuries, including a down-regulation of the TH1 response and up-regulation of the TH2 response.

METHODS

The PubMed, Medline, and Ovid search engines were queried for relevant human studies. Bibliographies were also meticulously reviewed.

RESULTS

An interesting and potentially clinically relevant pattern of immune dysregulation exists after injury. The type 1 T-helper cell (TH1) response is suppressed as illustrated by diminished interleukin (IL)-2, interferon (IFN)-gamma, and IL-12 levels after major injury. The enhancement of the TH2 response is marked by elevated IL-10 and IL-4. Certain cytokine profiles, ratios, and polymorphisms may help identify patients at increased risk of systemic inflammatory response syndrome (SIRS), sepsis, multiple organ failure (MOF), and deep venous thrombosis. The most promising prognostic indicators to date are decreased production of the IL-12, elevated IL-10, soluble IL-2 receptor-a (sIL-2Ra), and IL-18 levels, IL-18 promoter polymorphisms, the IL-6:IL-10 ratio, and the degree of TH1 suppression as measured by diminished IL-2 and IFN-gamma. The Cytokine sections are subdivided into basic science, human studies, animal studies (when necessary), and directed therapeutics. The outcomes of sepsis, SIRS, or MOF are generally discussed together.

CONCLUSIONS

T-cell-specific immunologic changes occur after major injury. Identification of those TH1/TH2 cytokine profiles associated with worse prognosis may one day allow clinicians to risk stratify injured patients and identify those at increased risk of developing SIRS, sepsis, MOF, and deep venous thrombosis. Immune-targeted therapies may eventually serve as effective treatments in the acute setting to decrease morbidity and mortality, and to improve the management and prognosis of those patients at risk for developing postinjury complications.

The study of co-morbid conditions in children with allergic rhinitis, from Mumbai, Maharashtra, India

Allergic rhinitis (AR), an allergen-induced inflammation of the nasal mucosa, is frequently associated with co-morbid conditions. It is important to recognize the onset and existence of these co-morbid conditions, for adequate treatment and prevention of the development of new allergen sensitizations and air-way hypersensitivities. The aim of our study was to determine the prevalence of co-morbid conditions associated with AR, in Indian children. We selected 65 consecutive children below the age of 18 years, who attended the Allergy and Asthma Clinic of our hospital, between March 1, 2005 to November 30, 2006 and compared them with the available literature. The most common co-morbid condition with AR was asthma (75.4%), followed by urticaria (33.9%), conjunctivitis (29.2%) and sinusitis (23.1%) in that order. Two patients (3.1%) each, had adenoid hypertrophy and nasal polyps. Psoriasis was seen in 4/65 (6.2%). Four patients (6.2%) were free from any co-morbid conditions as opposed to 61/65 (93.8%), who suffered from one to three co-morbid conditions each. Co-morbid conditions are a rule rather than an exception, the most common association being asthma. Asthma often is asymptomatic and routine PFT testing is valuable. The association of psoriasis is interesting.

Pathogenesis and clinical features of psoriasis

Psoriasis, a papulosquamous skin disease, was originally thought of as a disorder primarily of epidermal keratinocytes, but is now recognised as one of the commonest immune-mediated disorders. Tumour necrosis factor alpha, dendritic cells, and T-cells all contribute substantially to its pathogenesis. In early-onset psoriasis (beginning before age 40 years), carriage of HLA-Cw6 and environmental triggers, such as beta-haemolytic streptococcal infections, are major determinants of disease expression. Moreover, at least nine chromosomal psoriasis susceptibility loci have been identified. Several clinical phenotypes of psoriasis are recognised, with chronic plaque (psoriasis vulgaris) accounting for 90% of cases. Comorbidities of psoriasis are attracting interest, and include impairment of quality of life and associated depressive illness, cardiovascular disease, and a seronegative arthritis known as psoriatic arthritis. A more complete understanding of underlying pathomechanisms is leading to new treatments, which will be discussed in the second part of this Series.