Smoking and pathogenesis of psoriasis: a review of oxidative, inflammatory and genetic mechanisms

Interleukin-17A-induced production of acute serum amyloid A by keratinocytes contributes to psoriasis pathogenesis

BACKGROUND

Acute-serum Amyloid A (A-SAA), one of the major acute-phase proteins, is mainly produced in the liver but extra-hepatic synthesis involving the skin has been reported. Its expression is regulated by the transcription factors NF-κB, C/EBPβ, STAT3 activated by proinflammatory cytokines.

OBJECTIVES

We investigated A-SAA synthesis by resting and cytokine-activated Normal Human Epidermal Keratinocytes (NHEK), and their inflammatory response to A-SAA stimulation. A-SAA expression was also studied in mouse skin and liver in a model mimicking psoriasis and in the skin and sera of psoriatic and atopic dermatitis (AD) patients.

METHODS

NHEK were stimulated by A-SAA or the cytokines IL-1α, IL-17A, IL-22, OSM, TNF-α alone or in combination, previously reported to reproduce features of psoriasis. Murine skins were treated by imiquimod cream. Human skins and sera were obtained from patients with psoriasis and AD. A-SAA mRNA was quantified by RT qPCR. A-SAA proteins were dosed by ELISA or immunonephelemetry assay.

RESULTS

IL-1α, TNF-α and mainly IL-17A induced A-SAA expression by NHEK. A-SAA induced its own production and the synthesis of hBD2 and CCL20, both ligands for CCR6, a chemokine receptor involved in the trafficking of Th17 lymphocytes. A-SAA expression was increased in skins and livers from imiquimod-treated mice and in patient skins with psoriasis, but not significantly in those with AD. Correlations between A-SAA and psoriasis severity and duration were observed.

CONCLUSION

Keratinocytes could contribute to psoriasis pathogenesis via A-SAA production, maintaining a cutaneous inflammatory environment, activating innate immunity and Th17 lymphocyte recruitment.

The critical role of macrophages in the pathogenesis of hidradenitis suppurativa

INTRODUCTION

Hidradenitis suppurativa (HS) is a painful chronic inflammatory disease with a prevalence between 1 and 4% of general population. The pathogenesis of HS long eluded scientists, but growing evidence suggests that it is a consequence of inflammatory dysregulation.

FINDINGS

Recent studies suggest that dysregulated immune response to skin flora and overexpression of inflammatory cytokines leads to chronic skin inflammation seen in HS. Macrophages are the most numerous inflammatory cells found in HS infiltrates and release numerous pro-inflammatory cytokines such as IL-23, and IL-1β and TNF-α, exacerbating the inflammation and contributing to the pathogenesis of HS. Furthermore, in HS, there is dysregulated function of other immune players closely associated with macrophage function including: matrix metalloproteases (MMP) 2 and 9 overexpression, toll-like receptor upregulation, impaired Notch signalling, NLRP3 inflammasome upregulation, and dysregulated keratinocyte function. Lifestyle factors including obesity and smoking also contribute to macrophage dysfunction and correlate with HS incidence.

CONCLUSIONS

The overexpression of pro-inflammatory cytokines and subsequent efficacy of anti-cytokine biologic therapies highlights the importance of managing macrophage dysfunction. Future therapies should target key molecular drivers of macrophage dysfunction such as TLR2 and NLRP3 overexpression.

HLA-Cw6 homozygosity in plaque psoriasis is associated with streptococcal throat infections and pronounced improvement after tonsillectomy: A prospective case series

BACKGROUND

Carriage of the HLA-Cw*0602 allele is associated with a particular set of clinical features and treatment responses in psoriasis. Tonsillectomy can improve psoriasis.

OBJECTIVES

We sought to evaluate whether HLA-Cw*0602 predicts a favorable outcome after tonsillectomy of patients with psoriasis.

METHODS

This prospective case series followed up 28 tonsillectomized patients with plaque psoriasis for 24 months. The Psoriasis Area and Severity Index, Psoriasis Disability Index, and Psoriasis Life Stress Inventory were used for assessment. Tonsils were swabbed for bacteria and patients genotyped for HLA-Cw*0602.

RESULTS

After tonsillectomy, HLA-Cw*0602 homozygotes showed significantly more improvement, compared with heterozygous and HLA-Cw*0602-negative patients. Thus, Psoriasis Area and Severity Index score was reduced by 82% in the homozygous patients compared with 42% and 31%, respectively (P < .001), Psoriasis Disability Index score improved by 87% compared with 38% and 41%, respectively (P < .001), and Psoriasis Life Stress Inventory score was 82% reduced compared with 60% and 54%, respectively (P < .001). The homozygotes more often had psoriasis onset associated with a throat infection (P = .007) and an increased frequency of streptococcal throat infections per lifetime (P = .038).

LIMITATIONS

Few patients were included and some data were retrospective.

CONCLUSIONS

Homozygous HLA-Cw*0602 carriage in plaque psoriasis may predict a favorable outcome after tonsillectomy.

Age and gender differences in Framingham risk score and metabolic syndrome in psoriasis patients: A cross-sectional study in the Turkish population

Objective:

Psoriasis is associated with an increased frequency of cardiovascular risk factors. Metabolic syndrome (MS) and the Framingham risk score (FRS) are two different algorithms for evaluating cardiovascular risk. They include different features: waist circumference measurement is included in the MS criteria, whereas smoking, age, and gender are questioned in FRS. This study aimed to evaluate the frequency of MS and FRS in psoriasis patients compared with a control group and investigate the differences between MS and FRS.

Methods:

This was a cross-sectional study involving 300 psoriasis patients and 177 controls. MS, FRS, and disease severity were evaluated.

Results:

The frequency of MS was higher in females with psoriasis than in those in the control group (p=0.019). Females in the psoriasis group were more obese than those in the control group (p=0.036). FRS significantly differed between the patients and controls of age >60 years (p=0.006). The risk of hypertension in current and past smokers was higher in the psoriasis patients (OR=2.07 and 2.32–2.48, respectively) than in the control group. There was no statistically significant relationship among MS, FRS, and psoriasis severity (p>0.05).

Conclusion:

The results of this study support the evaluation of cardiovascular risk assessment in female psoriasis patients with MS and in male and elderly psoriasis patients with FRS.

Psoriasis and smoking: links and risks

Smoking is a complex environmental exposure influenced by genetic, environmental, and social factors. Nicotine is the principal alkaloid in tobacco that mediates the addicting effects of tobacco products. Tobacco is a mixture of more than 7,000 chemicals, and smoking is recognized as a risk factor for many diseases in humans, including cardiovascular and pulmonary disease and several cancers, and is the single most preventable cause of mortality worldwide. A number of inflammatory immune-related conditions have been associated with smoking, including psoriasis. Smoking affects the onset of psoriasis. In a pooled analysis of 25 case-control studies, the odds ratio of psoriasis among smokers was 1.78 (95% confidence interval [CI]: 1.53-2.06). A dose-effect relationship is also documented. In a pooled analysis of three cohort studies, the risk of incident psoriasis was 1.81 (95% CI: 1.38-2.36) in those who smoked 1-14 cigarettes per day, and 2.29 (95% CI: 1.74-3.01) in those who smoked ≥25 cigarettes per day. Smoking also impacts on the clinical severity of psoriasis, its response to treatment, and explains some of the associated comorbidities, eg, cardiovascular disease, inflammatory bowel disease, and several cancers (especially those of the respiratory tract). Data on the role of smoking in psoriatic arthritis are less consistent compared with those concerning psoriasis. Several pathophysiological mechanisms may explain the association of psoriasis with smoking, including oxidative stress, interaction with signaling pathways active in psoriasis, and vascular influences. In conclusion, psoriasis is just one of the many diseases associated with smoking, but it is visible and disabling. Dermatologists could play a major role in reducing the health burden of smoking by influencing the patients to change their behavior.

Smoking and Hand Dermatitis in the United States Adult Population

Background

Hand dermatitis is a common chronic relapsing skin disease resulting from a variety of causes, including endogenous predisposition and environmental exposures to irritants and allergens. Lifestyle factors such as smoking have been implicated in hand dermatitis.

Objective

To evaluate the association between tobacco exposure and hand dermatitis using the 2003~2004 National Health and Nutrition Examination Survey (NHANES) database.

Methods

Data were retrieved and analyzed from 1,301 participants, aged 20~59 years, from the 2003~2004 NHANES questionnaire study who completed health examination and blood tests. Diagnosis of hand dermatitis was based on standardized photographs of the dorsal and palmar views of the hands read by two dermatologists.

Results

There were 38 diagnosed cases of active hand dermatitis out of the 1,301 study participants (2.9%). Heavy smokers (>15 g tobacco daily) were 5.11 times more likely to have active hand dermatitis (odds ratio [OR], 5.11; 95% confidence interval [CI], 1.39~18.88; p=0.014). Those with serum cotinine >3 ng/ml were also more likely to have active hand dermatitis, compared with those with serum cotinine ≤3 ng/ml (OR, 2.50; 95% CI, 1.26~4.95; p=0.007). After adjusting for confounding factors such as age, atopic diathesis, occupational groups, and physical activity, the association between tobacco exposure and active hand dermatitis remained significant.

Conclusion

Smoking has a significant association with the presence of active hand dermatitis. It is important to consider smoking cessation as part of management of hand dermatitis.

Integrating lifestyle-focused approaches into psoriasis care: improving patient outcomes?

Psoriasis is one of the most well described cutaneous disorders, with a large body of literature devoted to describing its pathogenesis and treatment. In recent years, attention has turned toward the mechanisms by which lifestyle can impact psoriatic disease, and how lifestyle interventions may help to alleviate cutaneous, rheumatological, and comorbid disease in the setting of psoriasis. The following review explores our current understanding of the interaction between lifestyle factors and psoriasis and describes outcomes of interventions meant to target these factors.

Psoriasis and Smoking: A Systematic Literature Review and Meta-Analysis With Qualitative Analysis of Effect of Smoking on Psoriasis Severity

BACKGROUND

Smoking has been associated with psoriasis prevalence and severity.

OBJECTIVE

To evaluate prevalence of smoking in patients with psoriasis and to examine the relationship between smoking and psoriasis severity.

METHODS

MEDLINE, EMBASE, and Cochrane databases (1960-2012) and conference proceedings (2010-2012) were systematically searched using keywords relevant to psoriasis and smoking. Controlled studies addressing psoriasis and smoking status were included. A meta-analysis for the relative risk of smoking in psoriasis patients was performed.

RESULTS

Meta-analysis identified a significant association between smoking and psoriasis with a relative risk of 1.88 (95% CI, 1.66-2.13) for smoking in patients with psoriasis versus patients without psoriasis. Eight articles of 11 with data on smoking and psoriasis severity suggested that severity increases with smoking status.

CONCLUSIONS

This literature review is in favor of a positive association between the prevalence of smoking and psoriasis as well as an association between smoking and severity of psoriasis.

The association between smoking and the prevalence of metabolic syndrome and its components in patients with psoriasis aged 30 to 49 years

Introduction

Cigarette smoking may exacerbate and cause psoriasis. Moreover, smokers are more likely to develop insulin resistance and metabolic syndrome (MS).

Aim

To assess the prevalence of MS and its components in patients with psoriasis, who smoke, compared with the general Polish population of smokers.

Material and methods

We studied 29 patients with psoriasis (female = 9, male = 20), smokers, aged 30 to 49 years. Metabolic syndrome and its components were assessed using the IDF definition and compared to the results obtained in a representative sample of adult Poles in the NATPOL 2011 study in the same age group, including smokers.

Results

The results have shown that patients with psoriasis are more likely to be smokers (p < 0.0034) and the frequency of smoking in men is approximately 25% higher than in males of the control group (p < 0.0017). The prevalence of MS in patients with psoriasis who smoke was 27.58% and in the control group 25.2% (p > 0.05). Mean body mass index was 26.07 kg/m² in psoriasis patients and 25.59 kg/m² in the control group (p > 0.05), and abdominal obesity was 88.82 cm and 90.02 cm (p > 0.05), respectively. There were no differences in hypertension (34.48% vs. 31.6%, p < 0.05) and mean HOMA-IR (1.80 vs. 1.77, p > 0.05). In lipid parameters, the differences were observed only in women with psoriasis – higher levels of HDL, triglycerides and ApoB/ApoA1 index compared with addicted women in the control group.

Conclusions

Men with psoriasis are more often addicted to smoking. Women with psoriasis who smoke have often disturbances of the lipid profile.

Early detection of comorbidity in psoriasis: recommendations of the National Conference on Healthcare in Psoriasis

BACKGROUND

Psoriasis is associated with an increased rate of comorbidities, whose early detection has been adopted into the national healthcare goals. To date, agreed recommendations on early detection in the context of routine dermatological care are missing. The objective of this study was the interdisciplinary development of screening algorithms.

METHODS

The development of the consensus paper was based on a three-step process. First, the National Conference on Healthcare in Psoriasis, convening on behalf of the German Society of Dermatology (DDG) and the Professional Association of German Dermatologists (BVDD), developed a definition of the requirements, areas of application, conception, and methodology of a screening tool. Secondly, based on a literature search, individual working groups compiled evidence for the use of screening parameters. In a third step, an interdisciplinary working group adopted the algorithms in a Delphi consensus process.

RESULTS

The associated working groups evaluated more than 2,000 publications on 15 different comorbidities. A screening algorithm was agreed on for the following twelve indications: arterial hypertension, dyslipidemia, obesity, diabetes mellitus, metabolic syndrome, nonalcoholic steatohepatitis, depression, nicotine abuse, alcohol abuse, chronic inflammatory bowel disease, psoriasis arthritis, and malignant lymphoma. In this context, the requirements of everyday dermatological care were addressed in particular.

CONCLUSIONS

With respect to screening for comorbidities in psoriasis, standardized and consented algorithms are available, which - on national level - may be implemented as a screening tool within the framework of PsoNet - German Psoriasis Networks.

Comorbidities and cardiovascular risk factors in patients with psoriasis

BACKGROUND

Psoriasis is a chronic inflammatory disease and its pathogenesis involves an interaction between genetic, environmental, and immunological factors. Recent studies have suggested that the chronic inflammatory nature of psoriasis may predispose to an association with other inflammatory diseases, especially cardiovascular diseases and metabolic disorders.

OBJECTIVES

To describe the demographic, clinical, epidemiological, and laboratory characteristics of a sample of psoriasis patients; to assess the prevalence of cardiovascular comorbidities in this group of patients; and to identify the cardiovascular risk profile using the Framingham risk score.

METHODS

We conducted a cross-sectional study involving the assessment of 190 patients. Participants underwent history and physical examination. They also completed a specific questionnaire about epidemiological data, past medical history, and comorbidities. The cardiovascular risk profile was calculated using the Framingham risk score.

RESULTS

Patients' mean age was 51.5 ± 14 years, and the predominant clinical presentation was plaque psoriasis (78.4%). We found an increased prevalence of systemic hypertension, type 2 diabetes, metabolic syndrome, and obesity. Increased waist circumference was also found in addition to a considerable prevalence of depression, smoking, and regular alcohol intake. Patients' cardiovascular risk was high according to the Framingham risk score, and 47.2% of patients had moderate or high risk of fatal and non-fatal coronary events in 10 years.

CONCLUSIONS

Patients had high prevalence of cardiovascular comorbidities, and high cardiovascular risk according to the Framingham risk score. Further epidemiological studies are needed in Brazil for validation of our results.

Effect of tonsillectomy on psoriasis: a systematic review

BACKGROUND

Streptococcal infection is associated with psoriasis onset in some patients. Whether tonsillectomy decreases psoriasis symptoms requires a systematic review of the literature.

OBJECTIVE

We sought to determine whether tonsillectomy reduces psoriasis severity through a comprehensive search of over 50 years of literature.

METHODS

We searched MEDLINE, CINAHL, Cochrane, EMBASE, Web of Science, and OVID databases (from August 1, 1960, to September 12, 2013) and performed a manual search of selected references. We identified observational studies and clinical trials examining psoriasis after tonsillectomy.

RESULTS

We included data from 20 articles from the last 53 years with 545 patients with psoriasis who were evaluated for or underwent tonsillectomy. Of 410 reported cases of patients with psoriasis who underwent tonsillectomy, 290 experienced improvement in their psoriasis. Although some patients who underwent tonsillectomy experienced sustained improvement in psoriasis, others experienced psoriasis relapse after the procedure.

LIMITATIONS

Fifteen of 20 publications were case reports or series that lacked control groups. Publication bias favoring reporting improved cases needs to be considered.

CONCLUSION

Tonsillectomy may be a potential option for patients with recalcitrant psoriasis associated with episodes of tonsillitis. Studies with long-term follow-up are warranted to determine more clearly the extent and persistence of benefit of tonsillectomy in psoriasis.

Psoriasis and smoking: a systematic review and meta-analysis

Psoriasis is an inflammatory skin disease associated with increased cardiovascular comorbidity. Smoking is associated with an increased risk of cardiovascular disease, and prior studies have suggested that patients with psoriasis are more likely to be active smokers. Smoking may also be a risk factor in the development of psoriasis. We conducted a systematic review and meta-analysis to assess the prevalence of smoking among patients with psoriasis, and we reviewed the contribution of smoking to the incidence of psoriasis. A total of 25 prevalence and three incidence studies were identified. The meta-analysis of prevalence studies included a total of 146 934 patients with psoriasis and 529 111 patients without psoriasis. Random effects meta-analysis found an association between psoriasis and current smoking [pooled odds ratio (OR) 1·78, 95% confidence interval (CI) 1·52-2·06], as well as between psoriasis and former smoking (pooled OR 1·62, 95% CI 1·33-1·99). Meta-regression analysis did not reveal any sources of study heterogeneity, but a funnel plot suggested possible publication bias. A subset of studies also examined the association between moderate-to-severe psoriasis and smoking, with a pooled OR of 1·72 (95% CI 1·33-2·22) for prevalent smoking. The three incidence studies found an association between smoking and incidence of psoriasis, with a possible dose-effect of smoking intensity and duration on psoriasis incidence. These findings suggest that smoking is an independent risk factor for the development of psoriasis, and that patients with established psoriasis continue to smoke more than patients without psoriasis.

Increased numbers of tryptase-positive mast cells in the healthy and sun-protected skin of tobacco smokers

BACKGROUND

Tobacco smoking may cause skin aging through mast cell proteinases.

OBJECTIVE

To compare the numbers of mast cells showing tryptase and chymase in the healthy-looking skin of smokers and non-smokers.

METHODS

The study subjects consisted of 80 males, 42 of whom were smokers and 38 non-smokers. A skin biopsy from the medial arm was processed for immunohistochemical staining of tryptase and chymase, as well as chymase inhibitors alpha-1-proteinase inhibitor (alpha-1-PI) and alpha-1-antichymotrypsin (alpha-1-AC).

RESULTS

The number of tryptase(+) mast cells was significantly higher in the smoker group (84 ± 32 cells/mm(2)) than in the non-smoker group (70 ± 32 cells/mm(2)) (p = 0.044). Likewise, the number of chymase(+) mast cells was higher in the smoker group (89 ± 20 vs. 80 ± 22 cells/mm(2)), though statistical significance was not reached (p = 0.07). No significant difference was observed in alpha-1-PI(+) and alpha-1-AC(+) cells.

CONCLUSION

Especially tryptase, but probably also chymase, may have an influence on the skin of smokers, such as wrinkling and aging.

Combined effects of the BDNF rs6265 (Val66Met) polymorphism and environment risk factors on psoriasis vulgaris

Smoking, alcohol consumption and higher body mass index (BMI) are well established risk factors for psoriasis and also associated with the clinical traits of the disease. And the genetic influences on these three risk factors indeed exist. Previously studies have demonstrated these risk factors related genetic variants may also play a role in the development of risk factors-related diseases. Then we performed a hospital-based study in order to evaluate the combined effect of the risk factors and their related polymorphism rs6265 in brain-derived neurotrophic factor (BDNF) gene on psoriasis vulgaris (PV) risk and clinic traits. The case-control study involved 660 subjects including 345 cases and 315 controls in Chinese Han population. The variant of rs6265 was typed by SNaPshot Multiplex Kit (Applied Biosystems Co., USA). We confirmed that higher BMI (≥25), smoking and alcohol consumption were risk factors for PV, and the estimated ORs were 1.63(95 % confidence interval (CI); 1.12-2.37), 2.09(95 % CI; 1.44-3.03) and 1.65(95 % CI; 1.15-2.37) respectively. Genotype and allele distributions did not differ significantly between case and control. However, we found combined effect of rs6265 genotype (GG) and higher BMI (≥25) increased risk of PV (OR = 2.09; 95 % CI, 1.02-4.28; P < 0.05; adjusted OR = 3.19; 95 % CI, 1.37-7.45; P < 0.05) and clinically severity of PV (OR = 2.71; 95 % CI, 1.09-6.72; P < 0.05; adjusted OR = 1.25; 95 % CI, 1.10-1.40; P < 0.05). But none such significant combined effect was observed between others genotype (AA and AG) and other risk factors. In conclusions, the combined effect of BDNF rs6265 genotype (GG) and higher BMI may increases the risk and clinical severity of PV in Chinese Han population.

Combined effect between CHRNB3-CHRNA6 region gene variant (rs6474412) and smoking in psoriasis vulgaris severity

BACKGROUND

Many factors associated with causing psoriasis have been reported, such as the genetic and environmental factors. Smoking is one of the well-established environmental risk factors for psoriasis and also associated with the disease severity. In addition, several studies of psoriasis and psoriatic arthritis have documented gene-environment interactions involving smoking behavior. Although gene polymorphisms on nicotinic acetylcholine receptor subunits CHRNB3-CHRNA6 region gene have been found to correlate with smoking behavior and lung cancer susceptibility in Chinese Han population, the combined effect between the smoking-related genetic variants and smoking behavior on psoriasis vulgaris (PV) has been unreported.

OBJECTIVE

To evaluate the combined effect of the smoking-related (rs6474412-C/T) polymorphism on CHRNB3-CHRNA6 region gene and smoking behavior on PV risk and clinic traits in Chinese Han population.

METHODS

A hospital-based case-control study including 672 subjects (355 PV cases and 317 controls) was conducted. The variant of rs6474412 was typed by SNaPshot Multiplex Kit (Applied Biosystems Co., USA).

RESULTS

The higher body mass index (BMI≥25), smoking behavior and alcohol consumption were risk factors for PV, and the estimated ORs were 1.55 (95% CI, 1.09-2.29), 1.74 (95% CI, 1.22-2.49) and 1.81 (95% CI, 1.25-2.62) respectively. The smoking patients had more severe conditions than non-smokers (OR=1.71, 95% CI, 1.08-2.70, P=0.020). The alleles and genotypes of rs6474412 were not associated with risk of PV, but the combined effect of rs6474412 genotype (TT) and smoking behavior increased severity of PV (OR=5.95; 95% CI, 1.39-25.31; P<0.05; adjusted OR=2.20; 95% CI, 1.55-3.14; P<0.001).

CONCLUSIONS

Our results demonstrate that the combined effect of rs6474412-C/T polymorphism in smoking-related CHRNB3-CHRNA6 region gene and smoking behavior may not confer risk to PV, but may have impact on PV severity in Chinese Han population.

Resveratrol protects SR-B1 levels in keratinocytes exposed to cigarette smoke

Cigarette smoking (CS) has been strongly linked to several health conditions including heart disease, lung cancer, and other respiratory and circulatory ailments. Deleterious effects of cigarette smoking on skin have also been well documented, but unlike effects on other organs, damage does not depend upon inhalation. The upper layer of the skin, the stratum corneum (rich in cholesterol fatty acids and ceramide), is very susceptible to damage induced by exposure to environmental stressors that can modify its lipid composition and thereby affect its function of protecting skin from dehydration. Scavenger receptor B1 (SR-B1) is involved in the uptake of cholesterol in several tissues including skin. We previously demonstrated that CS exposure induces formation of aldehyde (HNE) adducts that decrease SR-B1 expression. As topical resveratrol, a well-known polyphenolic stilbene, has been demonstrated to show benefits against skin disorders, we investigated its possible role as a protective agent against CS-induced reduction of SR-B1 expression in cutaneous tissue. In this study, we demonstrate that resveratrol at doses ranging from 0.5 to 10 μM is not toxic and is able to increase SR-B1 protein levels in a dose-dependent manner in human keratinocytes. Moreover, when the cells that were pretreated with various doses of resveratrol were exposed to CS, the loss of SR-B1 was prevented in a dose-dependent manner. In addition, in keratinocytes, resveratrol was also able to prevent an increase in HNE-protein adducts induced by CS. In particular resveratrol was able to prevent HNE-SR-B1 adduct formation. Thus, resveratrol seems to be a natural compound that could provide skin with a defense against exogenous stressors by protecting the essential cholesterol receptor, SR-B1.

Infliximab treatment of psoriasis in supervised infusion centers: case management experience

Psoriasis is a systemic chronic inflammatory disease that affects 1-3% of the world's population. Knowledge of the pathogenesis of psoriasis, particularly in the understanding of the role of T cells and tumor necrosis factor α (TNFα), and advances in immunology have led to the development of biological agents, which, due to their great effectiveness, speed of response and good tolerability, have revolutionized patient management. One of these is infliximab, a human chimeric immunoglobulin G1 monoclonal antibody composed of human antibody constant regions and murine variable regions that was developed specifically to target TNFα. The six cases presented in this series highlight the feasibility, efficacy and safety of infliximab for psoriasis when administered in a variety of patients in several infusion centers across Spain. All six patients showed improvement in their psoriasis after the initiation of infliximab and no significant tolerability issues or injection site reactions were reported, despite the presence of several comorbid conditions or patient characteristics that traditionally reduce the efficacy of psoriasis treatments. This suggests that while the management of psoriasis patients with comorbid conditions and various unfavorable prognostic characteristics requires a multidisciplinary approach to ensure the patient obtains the best therapeutic response, infliximab is an effective and well tolerated treatment in these patients.

Tobacco smoking effect on HIV-1 pathogenesis: role of cytochrome P450 isozymes

INTRODUCTION

Tobacco smoking is highly prevalent among the HIV-1-infected population. In addition to diminished immune response, smoking has been shown to increase HIV-1 replication and decrease response to antiretroviral therapy, perhaps through drug-drug interaction. However, the mechanism by which tobacco/nicotine increases HIV-1 replication and mediates drug-drug interaction is poorly understood.

AREAS COVERED

In this review, the authors discuss the effects of smoking on HIV-1 pathogenesis. Since they propose a role for the cytochrome P450 (CYP) pathway in smoking-mediated HIV-1 pathogenesis, the authors briefly converse the role of CYP enzymes in tobacco-mediated oxidative stress and toxicity. Finally, the authors focus on the role of CYP enzymes, especially CYP2A6, in tobacco/nicotine metabolism and oxidative stress in HIV-1 model systems monocytes/macrophages, lymphocytes, astrocytes and neurons, which may be responsible for HIV-1 pathogenesis.

EXPERT OPINION

Recent findings suggest that CYP-mediated oxidative stress is a novel pathway that may be involved in smoking-mediated HIV-1 pathogenesis, including HIV-1 replication and drug-drug interaction. Thus, CYP and CYP-associated oxidative stress pathways may be potential targets to develop novel pharmaceuticals for HIV-1-infected smokers. Since HIV-1/TB co-infections are common, future study involving interactions between antiretroviral and antituberculosis drugs that involve CYP pathways would also help treat HIV-1/TB co-infected smokers effectively.

Epicardial fat thickness is independently associated with psoriasis

BACKGROUND

Several studies have showed an association between psoriasis and cardiovascular (CV) diseases and metabolic syndrome (MS). Assessment of CV risk in patients with psoriasis has become an important issue. Epicardial fat thickness (EFT) is an emerging cardiometabolic risk factor and has been shown to be related to atherosclerosis. EFT has not been studied in the context of psoriasis.

OBJECTIVE

To compare the EFT in psoriasis patients with that in control subjects.

METHODS

31 patients with psoriasis and 32 control subjects were included in this case-control study. EFT was evaluated by two-dimensional transthoracic echocardiography.

RESULTS

EFT was significantly higher in psoriasis patients compared to controls (p = 0.027). Multiple linear regression analysis showed that the association of EFT with psoriasis was independent of MS and age.

CONCLUSION

EFT, which has been suggested as a cardiometabolic risk factor in various diseases, is also independently associated with psoriasis.

The role of T helper (TH)17 cells as a double-edged sword in the interplay of infection and autoimmunity with a focus on xenobiotic-induced immunomodulation

Extensive research in recent years suggests that exposure to xenobiotic stimuli plays a critical role in autoimmunity induction and severity and that the resulting response would be exacerbated in individuals with an infection-aroused immune system. In this context, heavy metals constitute a prominent category of xenobiotic substances, known to alter divergent immune cell responses in accidentally and occupationally exposed individuals, thereby increasing the susceptibility to autoimmunity and cancer, especially when accompanied by inflammation-triggered persistent sensitization. This perception is learned from experimental models of infection and epidemiologic studies and clearly underscores the interplay of exposure to such immunomodulatory elements with pre- or postexposure infectious events. Further, the T_H17 cell subset, known to be associated with a growing list of autoimmune manifestations, may be the “superstar” at the interface of xenobiotic exposure and autoimmunity. In this review, the most recently established links to this nomination are short-listed to create a framework to better understand new insights into T_H17's contributions to autoimmunity.

Clinical and histologic diagnostic guidelines for psoriasis: a critical review

Psoriasis is a common inflammatory skin disease that is associated with joint, psychiatric, and cardiovascular comorbidities. Diagnosis of plaque psoriasis is dependent primarily on characteristic physical findings and history. Given the varied clinical presentations of psoriasis and its mimicry to other papulosquamous skin diseases, it may be difficult for nondermatologists to diagnose psoriasis. Currently, no diagnostic criteria for plaque psoriasis have been validated in clinical studies. In this paper, we provide diagnostic guidelines for the nondermatologist to aid them in recognizing psoriasis.

Paraoxonase 1 (PON1) 55 polymorphism, lipid profiles and psoriasis

BACKGROUND

Paraoxonase 1 (PON1) is a serum high-density lipoprotein-bound enzyme with antioxidant function. It hydrolyses lipid peroxides, protecting low-density lipoproteins from oxidative modifications. Patients with psoriasis are at greater risk of oxidative stress, which is associated with abnormal plasma lipid metabolism.

OBJECTIVES

In this study, association of the PON1 55 M allele with serum arylesterase (ARE) activity, malondialdehyde (MDA), lipid profiles and psoriasis was investigated.

METHODS

The present case-control study consisted of 100 patients with psoriasis with and without cardiovascular diseases (mean age 35·3 years) and 100 sex- and age-matched unrelated healthy controls (mean age 35·7 years) from the population of western Iran. The PON1 55 Met>Leu polymorphism was detected by polymerase chain reaction-restriction fragment length polymorphism. Serum ARE activity, MDA, and lipid and apolipoprotein levels were determined spectrophotometrically, by high-performance liquid chromatography and by enzyme assay, respectively.

RESULTS

The presence of the PON1 55 M allele was found to be associated with psoriasis (odds ratio = 1·96, P = 0·017). The patients with psoriasis with the PON1 M (M/L + M/M) allele had higher MDA levels (4·12 ± 0·88 vs. 2·24 ± 0·55 μmol L(-1) , P < 0·001), apolipoprotein B (APOB)/APOA1 ratio (0·91 ± 0·66 vs. 0·66 ± 0·35, P = 0·004), APOB (111 ± 38·7 vs. 88·3 ± 22·5 mg mL(-1) , P = 0·001) and lipoprotein(a) [LP(a)] (21·9 ± 18·4 vs. 15·8 ± 16·6 mg mL(-1) , P = 0·034), but lower ARE activity (39·6 ± 11 vs. 45·9 ± 11·8 U mL(-1) , P = 0·031) than the control subjects. ARE activity showed a significant positive correlation with APOA1 and a negative correlation with MDA concentration in patients with psoriasis.

CONCLUSIONS

The PON1 55 M allele is a risk factor for psoriasis. Carriers of this allele have high levels of MDA, APOB and LP(a), a high APOB/APOA1 ratio and low ARE activity. These results indicate that oxidative stress, impairment of the antioxidant system and abnormal lipid metabolism may play a role in the pathogenesis and progression of psoriasis and its related complications. These data suggest that patients with psoriasis are more susceptible to vascular diseases.

TNIP1/ANXA6 and CSMD1 variants interacting with cigarette smoking, alcohol intake affect risk of psoriasis

BACKGROUND

Psoriasis is a common multi-factorial skin disease, in which gene-gene and gene-environment interactions may affect the onset, manifestation and clinical course.

OBJECTIVE

To investigate the underlying gene-environment interaction among several established susceptibility genes, cigarette smoking and alcohol intake.

METHODS

Using a two-stage case-control design, we searched for pairwise interactions between cigarette smoking and alcohol intake respectively with 9 single nucleotide polymorphisms (SNPs) at ERAP1, PTTG1, CSMD1, GJB2, SERPINB8, ZNF816A and TNIP1/ANXA6 that have been associated with risk for psoriasis in 7,223 subjects. Multiple logistic regression analysis was used for data analysis.

RESULTS

Significant interactions were found for alcohol intake with rs3762999 (p=0.0257) and rs999556 (p=0.0071) at TNIP/ANXA6; and for cigarette smoking with rs7007032 (p=0.0023) and rs10088247 (p=0.0023) at CSMD1.

CONCLUSION

This study provides empirical evidence for the gene-environment interactions between TNIP1/ANXA6 and alcohol use, CSMD1 and cigarette smoking, highlighting the importance of gene-environment interactions in the pathogenesis of psoriasis.

Transcriptome alterations induced by cigarette smoke

Cigarette smoke alters the transcriptome of multiple tissues; those directly exposed to toxic products and those exposed to circulating components and metabolic products of tobacco smoke. In most tissues and organs that have been studied, the smoking transcriptome is characterized by increased expression of antioxidant and xenobiotic genes as well as a wide spectrum of inflammation-related genes, and potential oncogenic genes. Smoking is associated with an increased incidence of cancer in a number of organs both those directly exposed (lungs and airways) and those indirectly exposed (bladder, liver, pancreas). Individual transcriptomic responses vary, based to some degree on as yet to be clarified genetic factors, and likely how and what the individual has smoked. The complexity of individual responses to tobacco exposure and of smoking-related cancers in various organs is beginning to be revealed in transcriptomic and whole genome sequencing studies, of both tumors and cytologically normal appearing cells that have been exposed to cigarette smoke or its products creating a genomic "field of injury." The recent application of next generation sequencing to defining the transcriptome alterations induced by cigarette smoke holds the promise of discovering new approaches to personalized prevention and treatment of smoking-related lung diseases in the future.

The relationship between oxidative stress, smoking and the clinical severity of psoriasis

BACKGROUND

Recent studies suggested that increased oxidant products and decreased antioxidant system functions may be involved in the pathogenesis of psoriasis. In this study, we investigated total oxidative status, Paraoxonase (PON)1/arylesterase enzyme activities and severity of the disease in smoker and non-smoker psoriatic patients.

METHODS

Fifty-four patients with plaque type psoriasis (28 smokers and 26 non-smokers) and 62 healthy volunteers (16 smokers and 46 non-smokers) were enrolled in the study. Serum total oxidant status (TOS), total antioxidant capacity (TAC) and arylesterase levels were measured, and oxidative stress index (OSI) was calculated in all participants.

RESULTS

Psoriasis Area and Severity Index scores were significantly higher in smoker patients than in non-smoker patients (P = 0.014). Both smoker and non-smoker patients had significantly increased TOS levels and OSI values and decreased TAC levels than healthy subjects (all P values = 0.000). The TAC and TOS levels, OSI values and arylesterase activities were similar between smoker and non-smoker patients. The levels of triglyceride (TG), total cholesterol (TC), low-density lipoprotein (LDL) and high-density lipoprotein (HDL) were not significantly different between smoker and non-smoker psoriasis patients. When compared with non-smoking controls, only smoking psoriasis patients had significantly higher TG (P = 0.005), lower HDL (P = 0.022) and lower arylesterase levels (P = 0.015). There were no significant correlations with Psoriasis Area and Severity Index (PASI) scores and TAC, TOS, OSI, TG, TC, HDL and LDL levels in all psoriasis patients.

CONCLUSIONS

Oxidative stress is increased in psoriasis patients regardless of their smoking status. The decreased arylesterase activity in smoker psoriasis patients suggested that smoking may be a considerable risk factor that increases the severity of psoriasis by increasing oxidative stress in these patients.

Involvement of inflammatory factors in pancreatic carcinogenesis and preventive effects of anti-inflammatory agents

Chronic inflammation is known to be a risk for many cancers, including pancreatic cancer. Heavy alcohol drinking and cigarette smoking are major causes of pancreatitis, and epidemiological studies have shown that smoking and chronic pancreatitis are risk factors for pancreatic cancer. Meanwhile, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) are elevated in pancreatitis and pancreatic cancer tissues in humans and in animal models. Selective inhibitors of iNOS and COX-2 suppress pancreatic cancer development in a chemical carcinogenesis model of hamsters treated with N-nitrosobis(2-oxopropyl)amine (BOP). In addition, hyperlipidemia, obesity, and type II diabetes are also suggested to be associated with chronic inflammation in the pancreas and involved in pancreatic cancer development. We have shown that a high-fat diet increased pancreatic cancer development in BOP-treated hamsters, along with aggravation of hyperlipidemia, severe fatty infiltration, and increased expression of adipokines and inflammatory factors in the pancreas. Of note, fatty pancreas has been observed in obese and/or diabetic cases in humans. Preventive effects of anti-hyperlipidemic/anti-diabetic agents on pancreatic cancer have also been shown in humans and animals. Taking this evidence into consideration, modulation of inflammatory factors by anti-inflammatory agents will provide useful data for prevention of pancreatic cancer.

[Psoriasis and inflammatory bowel diseases]

Psoriasis and inflammatory bowel diseases (Crohn's disease and ulcerative colitis) are among the immune-mediated inflammatory diseases. This group includes approximately 80 disorders, some of which can at times be associated in a single patient. In psoriasis, Crohn's disease may be observed slightly more frequently, but ulcerative colitis and celiac disease are also an issue. The underlying relations between these disorders comprise: i) genetic data obtained by genome-wide association studies that show the involvement of shared predisposing loci and/or genes, for example, in innate immunity; ii) immunological data: these disorders share inflammation effector mechanisms, particularly the activation pathway of Th17 lymphocytes, which explains the efficacy of anti-TNF antibodies and anti-IL-12/23; and iii) environmental co-factors such as smoking, possibly certain food proteins (gliadin, etc.), and bacterial infections that are probably decisive elements in the genesis of these diseases.

Oxidative balance and colon and rectal cancer: interaction of lifestyle factors and genes

Pro-oxidant and anti-oxidant genetic and lifestyle factors can contribute to an individual's level of oxidative stress. We hypothesize that diet, lifestyle and genetic factors work together to influence colon and rectal cancer through an oxidative balance mechanism. We evaluated nine markers for eosinophil peroxidase (EPX), two for myeloperoxidase (MPO), four for hypoxia-inducible factor-1A (HIFIA), and 16 for inducible nitric oxide synthase (NOS2A) in conjunction with dietary antioxidants, aspirin/NSAID use, and cigarette smoking. We used data from population-based case-control studies (colon cancer n=1555 cases, 1956 controls; rectal cancer n=754 cases, 959 controls). Only NOS2A rs2297518 was associated with colon cancer (OR 0.86 95% CI 0.74, 0.99) and EPX rs2302313 and MPO rs2243828 were associated with rectal cancer (OR 0.75 95% CI 0.59, 0.96; OR 0.81 95% CI 0.67, 0.99 respectively) for main effects. However, after adjustment for multiple comparisons we observed the following significant interactions for colon cancer: NOS2A and lutein, EPX and aspirin/NSAID use, and NOS2A (4 SNPs) and cigarette smoking. For rectal cancer we observed the following interactions after adjustment for multiple comparisons: HIF1A and vitamin E, NOS2A (3SNPs) with calcium; MPO with lutein; HIF1A with lycopene; NOS2A with selenium; EPX and NOS2A with aspirin/NSAID use; HIF1A, MPO, and NOS2A (3 SNPs) with cigarette smoking. We observed significant interaction between a composite oxidative balance score and a polygenic model for both colon (p interaction 0.0008) and rectal cancer (p=0.0018). These results suggest the need to comprehensively evaluate interactions to assess the contribution of risk from both environmental and genetic factors.