Peripheral blood monocytes in psoriatic patients overproduce cytokines

Regulatory cells in the skin: Pathophysiologic role and potential targets for anti-inflammatory therapies

Inflammation is a fundamental defense mechanism to protect the body from danger, which becomes potentially harmful if it turns chronic. Therapeutic strategies aimed at specifically blocking proinflammatory signals, particularly cytokines, such as IL-4, IL-6, IL-13, IL-17A, or TNF-α, have substantially improved our ability to effectively and safely treat chronic inflammatory diseases. Much less effort has been made to better understand the role of potential anti-inflammatory mechanisms. Here we summarize the current understanding of regulatory cell populations in the context of chronic inflammation, namely macrophages, Langerhans cells, myeloid-derived suppressor cells, and regulatory T and B lymphocytes. Emphasis is given to the skin because many different immune-related diseases occur in the skin. Development, phenotype, function, and evidence for their role in animal models of inflammation, as well as in the corresponding human diseases, are described. Finally, the feasibility of using regulatory cells as targets for potentially disease-modifying therapeutic strategies is discussed.

Downregulated Caveolin-1 expression in circulating monocytes may contribute to the pathogenesis of psoriasis

Caveolin-1 (CAV-1) is the principal component of caveolae that regulates a variety of signaling molecules and receptors. Our previous study revealed CAV-1 reduction in the epidermis of patients with psoriasis, which leads to enhanced Janus kinase/signal transducer and activator of transcription activation and cytokine production, suggesting that aberrant CAV-1 expression may contribute to psoriatic inflammation. This study aimed to investigate whether abnormal modulation of CAV-1 on immune cells is involved in the pathogenesis of psoriasis. We observed that CAV-1 level in psoriasis patients was apparently reduced in peripheral blood mononuclear cells (PBMCs) and it was prominent in CD14⁺ monocytes. CAV-1 silencing in monocytes represented elevated levels of interleukin (IL)-1β and IL-6, and those had enhanced chemotaxis activity. In a murine model of psoriasis-like inflammation induced by imiquimod, we observed a significant CAV-1 reduction in PBMCs. Systemic administration of CAV-1 scaffolding domain peptide significantly improved the skin phenotype with less macrophage infiltration. Taken together, aberrant CAV-1 expression in monocytes may be involved in the pathogenesis of psoriasis.

IL-36γ Is a Strong Inducer of IL-23 in Psoriatic Cells and Activates Angiogenesis

The IL-1 family member cytokine IL-36γ is recognised as key mediator in the immunopathology of psoriasis, hallmarks of which involve the activation of both resident and infiltrating inflammatory myeloid cells and aberrant angiogenesis. This research demonstrates a role for IL-36γ in both myeloid activation and angiogenesis. We show that IL-36γ induces the production of psoriasis-associated cytokines from macrophages (IL-23 and TNFα) and that this response is enhanced in macrophages from psoriasis patients. This effect is specific for IL-36γ and could not be mimicked by other IL-1 family cytokines such as IL-1α. IL-36γ was also demonstrated to induce endothelial tube formation and branching, in a VEGF-A-dependent manner. Furthermore, IL-36γ-stimulated macrophages potently activated endothelial cells and led to increased adherence of monocytes, effects that were markedly more pronounced for psoriatic macrophages. Interestingly, regardless of stimulus, psoriasis monocytes showed increased adherence to both the stimulated and unstimulated endothelium when compared with monocytes from healthy individuals. Collectively, these findings show that IL-36γ has the potential to enhance endothelium directed leucocyte infiltration into the skin and strengthen the IL-23/IL-17 pathway adding to the growing evidence of pathogenetic roles for IL-36γ in psoriatic responses. Our findings also point to a cellular response, which could potentially explain cardiovascular comorbidities in psoriasis in the form of endothelial activation and increased monocyte adherence.

Vitamin D3 derivatives, alone or in combination with glucocorticoids, suppress streptococcal pyrogenic enterotoxin A-stimulated proliferation of peripheral blood mononuclear cells in patients with psoriasis

Bacterial colonization on skin or tonsil may influence the clinical response of patients with psoriasis to immunosuppressive drugs. However, few studies have investigated the effects of bacterial superantigens on therapy in these patients. Recently, combination therapy with topical glucocorticoids (GC) and vitamin D3 (VD3) appears to be more effective than GC or VD3 monotherapy for psoriasis. We evaluated the suppressive effects of betamethasone butyrate propionate (BBP), three VD3 derivatives (calcipotriol, maxacalcitol and tacalcitol), cyclosporin and BBP plus VD3, on concanavalin A (ConA)- or streptococcal pyrogenic enterotoxin A (SPEA)-stimulated proliferation of peripheral blood mononuclear cells (PBMC) obtained from 35 psoriasis patients. Drug concentrations effecting 50% inhibition concentration of ConA- or SPEA-stimulated PBMC proliferation were estimated. Cytokine levels of tumor necrosis factor-α, γ-interferon, interleukin-1b, -2, -4, -5, -6, -8 -10 and -12p70 in PBMC culture supernatants were measured with bead-array procedures. Suppression of PBMC proliferation by BBP was significantly lower when PBMC were stimulated by SPEA than when stimulated by ConA. In contrast, the suppressive effects of calcipotriol and tacalcitol increased significantly when PBMC were stimulated by SPEA than when stimulated by ConA. The suppressive effect of BBP on SPEA-stimulated PBMC proliferation was improved significantly by adding 1-1000 ng/mL calcipotriol, compared with BBP alone. Cytokine levels in PBMC culture supernatants were not significantly different between ConA- and SPEA-stimulated PBMC. Calcipotriol and BBP in combination markedly suppressed SPEA-stimulated PBMC proliferation. SPEA produced by colonization of hemolytic streptococci may reduce the efficacy of BBP but not VD3 derivatives in the treatment of psoriasis.

Myeloid-derived suppressor cells are elevated in patients with psoriasis and produce various molecules

Psoriasis is a debilitating chronic inflammatory disease. In addition to the characteristic effects on the skin, chronic inflammation associated with the disease is recognized to contribute to cardiovascular, hepatic and renal comorbidities. Immature myeloid regulatory cells, known as myeloid‑derived suppressor cells (MDSCs), have been demonstrated to accumulate in various diseases and chronic inflammatory states, including inflammatory bowel disease and various types of cancer. The results of the present study, obtained using flow cytometry and cell culture analysis of peripheral blood mononuclear cells from psoriasis and healthy patients, revealed that MDSC levels are significantly increased in the blood of patients with psoriasis compared with healthy controls. Furthermore, these cells are capable of producing various molecules, including matrix metalloproteinase‑9 and‑1, interleukin‑8, growth‑related oncogene, and monocyte chemoattractant protein 1. These molecules may recruit additional immune cells involved in the pathogenesis of the disease, and contribute to the chronic inflammatory state in these patients. Therefore, MDSCs, which have various immune regulatory functions, may contribute to the pathogenesis of psoriasis as a systemic inflammatory disease.

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.

Transcutaneous delivery of leflunomide nanoemulgel: Mechanistic investigation into physicomechanical characteristics, in vitro anti-psoriatic and anti-melanoma activity

The present study is a mechanistic validation of 'proof of concept' of effective topical delivery of leflunomide (LFD) nanoemulgel for localized efficient treatment of psoriatic lesions as well as melanoma affected skin regions. Hyperproliferation of keratinocytes in psoriasis and symbiotic relationship between keratinocytes and melanocytes, justifies the need of dual acting treatment. LFD is recently introduced significantly effective disease modifying anti-rheumatic drug and has been considered valuable for the treatment of psoriatic arthritis as well as melanoma. Current available treatments for psoriasis and melanoma are inefficient due to systemic side effects, poor transcutaneous permeation and thus present a challenge for development of novel colloidal carriers. We newly reformulated LFD as a nanoemulgel based on self nanoemulsifying technique using Capryol 90, Cremophor EL, Transcutol HP as nanoemulsifying components and Pluronic F127 as a gelling agent. This thermodynamically stable nanoemuslsifying preconcentrate after gelation showed mean globule size, 123.7 nm and viscosity 9620 ± 93 cp. Complete mechanical characterization was carried out using Texture Analyzer and hardness, adhesiveness and springiness index were found to be 523 gms, 431 gms and 1.02, respectively. Ex vivo permeation through rat abdominal skin revealed significant improvement in flux, apparent permeability coefficient, steady state diffusion coefficient and drug deposition in skin due to nanoemulsification of LFD. The in vitro cytoxicity of LFD nanoemulgel in human HaCaT, melanoma A375 and SK-MEL-2 cell lines showed significantly enhanced therapeutic response. In gist, LFD nanoemulgel for trancutaneous delivery will reduce the overall dose and drug consumption, by effectively localizing at the applied target site and will ultimately minimize systemic side effects.

Markers of systemic inflammation in psoriasis: a systematic review and meta-analysis

Studies investigating systemic inflammation in psoriasis use different serum markers and report discrepant results. We set out to determine whether systemic inflammation is elevated in patients with psoriasis compared with healthy controls, and to measure the extent of this elevation, by summarizing available data on serum inflammatory markers. PubMed, Embase and Web of Science were searched from inception to March 2011. We included studies comparing the serum inflammatory markers interleukin (IL)-1β, IL-6, IL-10, C-reactive protein (CRP), intracellular adhesion molecule (ICAM)-1, E-selectin and tumour necrosis factor (TNF)-α in patients with psoriasis and healthy controls. Differences in serum marker levels between patients and controls were pooled as standardized mean differences (SMDs; Cohen's d) using a random-effects model. Seventy-eight studies were eligible. Of the 7852 individuals included, 3085 had (severe plaque) psoriasis. The pooled SMDs were higher in patients with psoriasis than in healthy controls for IL-6 [d = 1·32, 95% confidence interval (CI) 0·83-1·81], CRP (d = 1·83, 95% CI 0·76-2·90), TNF-α (d = 1·32, 95% CI 0·86-1·79), E-selectin (d = 1·78, 95% CI 1·32-2·25) and ICAM-1 (d = 1·77, 95% CI 1·15-2·39). The SMD between cases and controls for IL-1β and IL-10 was not significant. Age had a significant effect on the SMD for IL-6 and TNF-α. For IL-6 the effect size was higher for plaque psoriasis studies (d = 1·98). The effect size was not influenced by the Psoriasis Area and Severity Index, measurement method or quality assessment. The pooled analyses suggest modest but significantly elevated levels of the proinflammatory cytokines in the serum of patients with psoriasis with predominantly severe disease. To what extent this modest increment is clinically relevant could be investigated in a synthesis of all studies measuring inflammation before and after antipsoriatic therapy.

Targeting TNF for Treatment of Cancer and Autoimmunity

Tumor necrosis factor-alpha (TNF-alpha) was first isolated two decades ago as a macrophageproduced protein that can effectively kill tumor cells. TNF-alpha is also an essential component of the immune system and is required for hematopoiesis, for protection from bacterial infection and for immune cell-mediated cytotoxicity. Extensive research, however, has revealed that TNF-alpha is one of the major players in tumor initiation, proliferation, invasion, angiogenesis and metastasis. The proinflammatory activities link TNF-alpha with a wide variety of autoimmune diseases, including psoriasis, inflammatory bowel disease, rheumatoid arthritis, systemic sclerosis, systemic lupus erythematosus, multiple sclerosis, diabetes and ankylosing spondylitis. Systemic inhibitors of TNF such as etanercept (Enbrel) (a soluble TNF receptor) and infliximab (Remicade) and adalimumab (Humira) (anti-TNF antibodies) have been approved for the treatment inflammatory bowel disease, psoriasis and rheumatoid arthritis. These drugs, however, exhibit severe side effects and are expensive. Hence orally active blockers of TNF-alpha that are safe, efficacious and inexpensive are urgently needed. Numerous products from fruits, vegetable and traditional medicinal plants have been described which can suppress TNF expression and TNF signaling but their clinical potential is yet uncertain.

Cytokines and anticytokines in psoriasis

BACKGROUND

Psoriasis is a chronic autoimmune hyperproliferative skin disease of varying severity affecting approximately 2-3% of the general population in the USA and Europe. Although the pathogenesis of psoriasis has not been fully elucidated, an immunologic-genetic relationship is likely. Cutaneous and systemic overexpression of various proinflammatory cytokines (TNF, interleukins, interferon-gamma) has been demonstrated in psoriatic patients.

METHODS

We reviewed the current database literature and summarized the involvement of cytokines and their receptors in the pathogenesis and treatment of psoriasis.

RESULTS

Although many cytokine/anti-cytokine therapies have been conducted, TNF antagonists in the treatment of both psoriasis arthropatica and vulgaris appear to be the most widely used clinically. Interestingly, the efficacy and tolerability of some cytokines (rhIL-11 or ABX-IL-8,) were found to be much lower than expected.

CONCLUSIONS

Preliminary results obtained with cytokine and anti-cytokine therapies appear promising and as such continued research is clearly indicated.

Smoking and the risk of psoriasis in women: Nurses' Health Study II

BACKGROUND

Psoriasis is a common, chronic, inflammatory skin disorder. Smoking may increase the risk of psoriasis, but no prospective data are available on this relation.

METHODS

We prospectively examined over a 14-year time period (1991-2005) the relation between smoking status, duration, intensity, cessation, and exposure to secondhand smoke, and incident psoriasis in 78,532 women from the Nurses Health Study II. The primary outcome was incident, self-reported, physician-diagnosed psoriasis.

RESULTS

We documented 887 incident cases of psoriasis. Compared with those who had never smoked, the multivariate relative risk (RR) of psoriasis was 1.78 (95% confidence interval [CI], 1.46 to 2.16) for current smokers and 1.37 (95% CI, 1.17 to 1.59) for past smokers. Compared with nonsmokers, the multivariate RR of psoriasis was 1.60 (95% CI, 1.31 to 1.97) for those who had smoked 11-20 pack-years and 2.05 (95% CI, 1.66 to 2.53) for those who had smoked > or =21 pack-years. Compared with never smokers, the multivariate RR of psoriasis was 1.61 (95% CI, 1.30 to 2.00) for those who quit smoking <10 years ago, 1.31 (95% CI, 1.05 to 1.64) for 10-19 years ago, and 1.15 (95% CI, 0.88 to 1.51) for > or =20 years ago. Prenatal and childhood exposure to passive smoke was associated with an increased risk of psoriasis.

CONCLUSIONS

In this prospective analysis, current and past smoking, and cumulative measures of smoking were associated with the incidence of psoriasis. The risk of incident psoriasis among former smokers decreases nearly to that of never smokers 20 years after cessation.

Molecular analysis of Malassezia microflora in the lesional skin of psoriasis patients

Systemic and focal infections by microorganisms have been known to induce or exacerbate psoriasis. To investigate the role of Malassezia species in the development of psoriasis, we analyzed the Malassezia microflora in psoriasis patients using a nested polymerase chain reaction (PCR) assay, and compared it with those in atopic dermatitis (AD) patients and healthy subjects. Fungal DNA was directly collected from the lesional and non-lesional skin of the trunk of 22 psoriasis patients by applying a transparent dressing. The extracted DNA was amplified by using specific primers designed for the PCR in the intergenic spacer or internal transcribed spacer area of the ribosomal RNA. All nine of the Malassezia species were detected at different rates from the 22 psoriasis patients. The overall detection rates in lesional and non-lesional skin of M. restricta, M. globosa and M. sympodialis were high (96%, 82% and 64%, respectively), whereas the detection rates of the other species were relatively low. However, there was no difference in the rates between lesional and non-lesional skin areas. The average number of Malassezia species detected in overall sites of the psoriasis patients was 3.7 +/- 1.6 species, although this fact showed no correlation with the severity of the symptoms. The number of Malassezia species detected was 4.1 +/- 1.9 in the AD patients, and 2.8 +/- 0.8 in the healthy subjects, suggesting that the skin microflora of psoriasis patients and AD patients show greater diversity than that of healthy subjects.

Effect of psychological stress on salivary interleukin-1beta in psoriasis

BACKGROUND

Psoriasis is a chronic inflammatory skin disease in which several Th1 cytokines such as interleukin-1 beta (IL-beta) have been shown to play a pivotal role. Psychological stress has also been implicated in triggering or exacerbating the disease.

METHODS

Salivary IL-1beta and cortisol levels of 25 patients with psoriasis were compared with those of 50 age- and sex-matched healthy controls under basal conditions and after a standardized stressful procedure including mental arithmetics and the Stroop Color-Word Naming Test.

RESULTS

At baseline, mean IL-1beta levels were higher in patients with psoriasis than controls (p <0.001), whereas mean cortisol levels did not differ significantly between groups. Although IL-1beta levels increased after stress among controls, they did not increase among patients with psoriasis, with a significant group-by-time interaction (p <0.01). After stress, cortisol levels were significantly increased in both groups as compared with baseline (p < or =0.001), without any group-by-time interaction. Perceived stress was similar among psoriatic patients and controls. There was no significant correlation between changes in IL-1beta and changes in cortisol.

CONCLUSIONS

The higher basal IL-1beta levels among psoriatic patients suggest that its production is increased. Changes in proinflammatory cytokine activity in psoriatic skin may play an important role in propagating inflammation. The blunted response of IL-1beta to stress observed in psoriatic patients may reflect a "ceiling effect", or be ascribed to a defective response of the immune system to adrenergic stimuli.

Unfavorable cardiovascular risk profiles in untreated and treated psoriasis patients

Psoriasis is a chronic inflammatory skin disease that is associated with an increased cardiovascular risk profile. The systemic inflammation present in psoriasis, various systemic treatments for psoriasis and an increased prevalence of unhealthy life style factors may all contribute to this unfavorable risk profile. The purpose of this article is to provide an overview of what is known about these risk factors in psoriasis, the way they influence the cardiovascular risk of psoriasis patients, and what can be done to reduce this risk. Genetic studies demonstrate that psoriasis and cardiovascular disease share common pathogenic features in which, for example inflammatory cytokines like TNF-alpha and IL-1 play an important role. The chronic inflammation in psoriasis has an unfavorable effect on the cardiovascular risk profile. Multiple cardiovascular risk factors seem to be influenced; the blood pressure, oxidative stress, dyslipidemia, endothelial cell dysfunction, homocysteine levels and blood platelet adhesion. Moreover, classic cardiovascular risk factors like smoking and obesity that have an increased prevalence among patients with psoriasis, indirectly also worsen the cardiovascular risk profile by stimulating the psoriasis activity. Systemic treatments in psoriasis reduce the cardiovascular risk by diminishing the inflammation, but it should be taken into account that most therapies also have adverse cardiovascular effects like dyslipidemia, hyperhomocysteinemia and hypertension. As a consequence preventive measures may be indicated at least during long-term treatments. Prospective research is warranted to accurately estimate the increased cardiovascular risk in psoriasis, to determine the underlying processes and to consider preventive measures according to the absolute risk of cardiovascular disease. The present overview provides data to advice health care providers to pay more attention to the cardiovascular risk profile in psoriasis patients.

Serum levels of TNF-alpha, IFN-gamma, IL-6, IL-8, IL-12, IL-17, and IL-18 in patients with active psoriasis and correlation with disease severity

Recent progress in the understanding of psoriasis has shown that the regulation of local and systemic cytokines plays an important role in its pathogenesis. The most often used psoriasis score is the psoriasis area and severity index (PASI). A simple laboratory test from a blood sample would be an attractive, patient-independent, and observer-independent marker of disease severity. To this end, we evaluated the association of serum levels of some proinflammatory cytokines in vivo and their correlation with severity of psoriasis. The serum levels of cytokines levels were determined with the use of the ELISA method. All mean values except IL-17 levels of patients were significantly higher than those of controls. There was a significant correlation between serum levels of IFN-γ, IL-12, IL-17, and IL-18, and severity of the disease. Psoriasis can be described as a T-cell-mediated disease, with a complex role for a variety of cytokines, which has led to the development of new immunomodulatory therapies. In this study, serum TNF-α, IFN-γ, IL-6, IL-8, IL-12, and IL-18 levels were significantly higher in active psoriatic patients than in controls. Furthermore, high levels of IFN-γ, IL-12, and IL-18 correlated with the clinical severity and activity of psoriasis, and those measurements of serum levels of these cytokines may be objective parameters for the disease severity.

Gene expression profiles in psoriasis: analysis of impact of body site location and clinical severity

BACKGROUND

Psoriasis is characterized by symmetry of plaques and modulation of multiple genes within those plaques.

OBJECTIVES

We compared gene expression profiles of plaques of psoriasis at different anatomical sites for both symmetrical and asymmetrical disease to ascertain whether the same genes were expressed.

METHODS

Gene expression profiles were analysed in biopsies from lesional and uninvolved skin from two groups of patients with either predominantly symmetrical or truncal plaques of psoriasis vulgaris, and from normal skin of healthy volunteers. Genomic analyses were performed using cDNA array and kinetically monitored reverse transcriptase-initiated polymerase chain reaction (kRT-PCR) approaches. A cluster of genes upregulated in involved psoriasis skin as compared with normal skin was identified using each of these two technologies.

RESULTS

Clustering of patients based on their gene expression profile did not reveal any correlation with family history of psoriasis, age at onset or association of psoriasis with arthritis. There was no difference in gene expression profile between the type (symmetrical vs. truncal) or location (left vs. right side of body) of psoriatic plaques. Gene expression profiles of involved psoriatic skin analysed by kRT-PCR analysis did correlate with both global (Psoriasis Area and Severity Index) and local (erythema, desquamation and plaque elevation) clinical severity.

CONCLUSIONS

These results indicate that it may be feasible to analyse the molecular effects of pharmacological agents on psoriatic skin in 'minizone' protocols, that the obtained data can be correlated with clinical severity and that plaques of psoriasis in the same individual express the same genes.

Lipoprotein glomerulopathy associated with psoriasis vulgaris: report of 2 cases with apolipoprotein E3/3

Lipoprotein glomerulopathy (LPG) is a rare disease, characterized by a special histology, including dilated glomerular capillaries filled with pale-stained and meshlike lipoprotein thrombi. It always presents with proteinuria or nephrotic syndrome. Although hyperlipidemia is not always seen, most patients have type III hyperlipoproteinemia with apolipoprotein (apo) E2/3 phenotyping. Although the clinical feature of LPG is rarely described, LPG associated with other glomerulopathy, including IgA nephropathy, membranous nephropathy, and lupus nephritis, has been documented. Until now, there have been no reports of psoriasis vulgaris associated with LPG. The authors present 2 cases of LPG with apo E3/3 genotyping associated with psoriasis vulgaris. The first patient was a 65-year-old woman who presented with nephrotic syndrome with daily urinary protein loss of 9.05 g and itchy erythematous scaly plaques on her trunk and lower limbs for 1 year. The renal biopsy results showed LPG, and the skin biopsy results showed psoriasis. The second patient was a 50-year-old man with history of psoriasis over his trunk and 4 limbs for 30 years. He also presented with nephrotic syndrome with daily urinary protein loss of 7.55 g. The renal biopsy results also showed LPG. The genotype of apo E showed E3/3, and lipoprotein electrophoresis showed a type III hyperlipoproteinemia-like pattern in both cases. The authors suggest that presence of apo E3/3 genotype cannot rule out the diagnosis of type III hyperlipoproteinemia and LPG. Besides, LPG should be included in the differential diagnosis of psoriatic patients with nephrotic syndrome, especially in Asian patients who show poor response to traditional therapy. Renal biopsy should be performed to make the definitive diagnosis.

Immunpathogenese der Psoriasis. Immunopathogenesis of Psoriasis

Psoriasis is a chronic inflammatory disease of the skin and the joints. Multiple factors contribute to the initiation of psoriasis. They include specific genetic characteristics such as major histocompatibility antigens and psoriasis susceptibility genes, as well as trigger factors, namely streptococcal infections. Today, psoriasis is considered as a T-lymphocyte mediated autoimmune disease, even though the putative autoantigen remains unknown. Bacterial proteins with similarity to structural proteins of keratinocytes are potential target antigens. As in other autoimmune diseases, inflammatory cytokines of the innate immune system initiate a cascade that activates inflammation locally in the skin, in the circulation and most likely also in lymph nodes. IFN-gamma-producing CD4+ Th1-lymphocytes seem to be of central importance in the pathogenesis of psoriasis as they critically influence differentiation and functioning of antigen presenting cells, mast cells, neutrophils and endothelial cells. This inflammatory cascade simultaneously provokes neoangiogenesis in the dermis and proliferation of keratinocytes. Based on this hypothesis, cytokines or anticytokine antibodies that either inhibit T-cell mediated inflammation or transform disease-inducing, pro-inflammatory Th1-lymphocytes into a phenotype with anti-inflammatory properties were tested in psoriasis. As both approaches improved psoriasis, they strongly support the current concept that views psoriasis as a Th1-lymphocyte mediated disease.

Increased microorganisms DNA levels in peripheral blood monocytes from psoriatic patients using PCR with universal ribosomal RNA primers

It has long been suspected that systemic and focal infections cause or exacerbate psoriatic lesions. We previously showed that peripheral blood monocytes in psoriatic patients are activated and overproduce inflammatory cytokines. In addition, it has been reported that macrophages activated by ingesting microorganisms release tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta. Therefore we hypothesized that the monocytes in psoriatic patients may be activated by ingesting microorganisms and overproduce inflammatory cytokines. We examined the detection of microorganism DNA in monocytes from 15 patients with psoriasis vulgaris and from 12 healthy controls. DNA was extracted from monocytes, and a polymerase chain reaction (PCR) assay was performed for the detection using universal primers from conserved regions of the bacterial 16S ribosomal RNA gene or the fungal 18S rRNA gene. At the same time, we calculated the psoriasis area and severity index (PASI) scores and analyzed their correlations with the microorganisms DNA levels. The results showed that bacterial 16S DNA levels in monocytes were significantly higher in psoriatic patients than in controls. The fungal 18S DNA levels were also higher in psoriatic patients than in controls, but the differences were not significant. Although the microorganisms DNA levels in monocytes of psoriatic patients were high, there was no correlation between the bacterial DNA levels in monocytes of the psoriatics and PASI scores. Our study suggests that monocytes in psoriatic patients engulf more bacteria than there in controls, causing an activation of monocytes and triggering the formation of new lesions in the initial stages of psoriasis.

Lipid analysis of peripheral blood monocytes in psoriatic patients using Fourier-transform infrared microspectroscopy

In psoriasis vulgaris, there are immunological abnormalities of T cells and monocytes. We previously demonstrated that monocytes in the peripheral blood of patients with psoriasis vulgaris are activated and produce an excess of inflammatory cytokines. It has long been suggested that fat metabolism is impaired in patients with this illness. In addition, it has been reported that macrophages activated by engulfing low density lipoprotein (LDL) immune complexes release large quantities of tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta. Hence we hypothesized that the monocytes of psoriatic patients are activated by engulfing lipids and overproduce inflammatory cytokines. Therefore we measured both the serum and monocyte levels of lipids in the peripheral blood of psoriatic patients. At the same time, we calculated the psoriasis area and severity index (PASI) scores and analyzed their correlation with the lipid kinetics. The results showed that the serum cholesterol ester level and the cholesterol ester level in monocytes of psoriatic patients were significantly higher than those in healthy individuals. However, the cholesterol ester level in monocytes of patients with hyperlipidemia was also high, and there was no correlation between cholesterol ester level in monocytes of psoriatics and PASI scores. The cholesterol ester level in the monocytes of psoriatic patients was high, but this does not seem to play an important role in the pathogenesis of psoriasis.

Decreased expression levels of L-selectin on subsets of leucocytes and increased serum L-selectin in severe psoriasis

L-selectin is a leucocyte adhesion molecule involved in leucocyte interactions with vascular endothelial cells. Following leucocyte activation L-selectin is endoproteolytically released from the cell surface. To assess whether psoriasis vulgaris results in systemic leucocyte activation, we examined expression levels of L-selectin on subsets of peripheral blood leucocytes from patients with psoriasis (n = 25) and normal control subjects. Serum levels of soluble L-selectin were quantified by ELISA in patients with psoriasis (n = 75), pustulosis palmaris et plantaris, and contact dermatitis, as well as normal control subjects. Psoriasis severity was evaluated by psoriasis area and severity index (PASI). L-selectin expression levels on CD4+ T cells, B cells, monocytes, and neutrophils from patients with severe-type psoriasis (PASI > or = 15) was significantly decreased compared with leucocytes from normal control subjects. Furthermore, L-selectin expression on CD4+ T cells showed good inverse correlation with PASI scores. Monocyte L-selectin expression was restored when the skin lesions of psoriasis were remitted. The frequencies of L-selectin+ CD4+ T cells or L-selectin+ CD8+ T cells from patients with psoriasis were almost normal. Serum L-selectin levels in patients with severe-type psoriasis were significantly higher than those in normal control subjects. These results suggest that subsets of leucocytes may be activated in psoriasis, and that L-selectin expression levels on some leucocyte subsets, especially CD4+ T cells, tend to correlate with disease severity of psoriasis.

Determination of Total Interleukin-8 in Whole Blood after Cell Lysis

Background: It has been shown that a high percentage of interleukin-8 (IL-8) in blood is cell associated. Recently, a simple method for determination of cell-associated IL-8 in whole blood after cell lysis has been described. The purpose of this study was to evaluate this method, to examine the influence of preanalytic sample handling, and to establish the concentration range of total IL-8 and its relation to age and sex in healthy subjects.

Methods: Total IL-8 content of whole blood was determined after lysing blood cells with Milenia® cell lysis solution. IL-8 in the resulting blood lysate was measured with the IMMULITE® IL-8 immunoassay.

Results: When freshly drawn blood was stored up to 48 h on ice, no significant changes in total IL-8 were measured in the subsequently prepared lysate, whereas with storage at room temperature, total IL-8 increased after 3 h from 94 ± 13 ng/L to 114 ± 16 ng/L (n = 10). In lysate stored for 48 h at 4 °C, marginal changes of the IL-8 concentration were noted, with storage at room temperature, only 76% ± 5% (n = 12) of initial concentration was recovered. From lysate frozen at −20 and −80 °C, respectively, 84% ± 4% and 93% ± 2% of initial IL-8 was recovered after 70 days (n = 10). IL-8 was measured with comparable precision in plasma (CV, 3.2–4.2%) and blood lysate (CV, 3.7–4.1%). When plasma was diluted with cell lysis solution, a slightly overestimated recovery (125% ± 3%) was observed; for lysate specimens with a cell lysis solution content ≥75%, the recovery after dilution was 98% ± 2%. In lysate prepared from 12 blood samples with exogenous IL-8 added, IL-8 recovery was 104% ± 2% (recovery from plasma &lt;35%). The median total IL-8 in blood lysates from 103 healthy subjects (22–61 years) was 83 ng/L of blood (2.5–97.5 percentile range, 49–202 ng/L of blood). In females but not in males, total IL-8 increased significantly with advancing age (P &lt;0.002). We found grossly increased total IL-8 in six pregnant women with amniotic infection syndrome.

Conclusions: The evaluated method allows the assessment of total IL-8 in blood with good performance when appropriate conditions of sample pretreatment are considered. The values in healthy volunteers all were above the detection limit of the IL-8 assay; therefore, slight changes of total IL-8 could be noted. Thus, the present method is a suitable tool to study the diagnostic relevance of total IL-8 in blood.

Overexpression of monocyte-derived cytokines in active psoriasis: a relation to coexistent arthropathy

An overexpression of inflammatory cytokines has been found in the lesional skin as well as peripheral blood in patients with psoriasis, although its etiological significance is not yet understood. In order to evaluate the cell type responsible for the elevated cytokines in the peripheral blood, we investigated cytokine profiles of the fractionated peripheral blood mononuclear cells (PBMCs) in 30 patients with psoriasis and 27 healthy controls. Without stimulation, higher levels of interleukin (IL)-1beta, IL-6, and IL-8 were produced by freshly isolated PBMCs from the patients than those from the controls. In the fractionated PBMCs, the monocyte-rich fractions were mainly responsible for the production of these cytokines and mRNA. The elevated levels of monocyte-derived cytokine mRNAs decreased following successful treatment with cyclosporin A. Although no correlation was found between the cytokine levels and the psoriasis area and severity index (PASI) scores, patients with arthropathy showed significantly high production levels of IL-1beta, IL-6, and IL-8. These findings suggest that monocytes are the major cell source producing inflammatory cytokines in the peripheral blood of psoriasis, and the increased cytokine levels are related to the coexistent arthropathy rather than the severity of cutaneous lesions.

Increased levels in vivo of mRNAs for IL-8 and macrophage inflammatory protein-1 alpha (MIP-1 alpha), but not of RANTES mRNA in peripheral blood mononuclear cells of patients with atopic dermatitis (AD)

Chemokines play an important role in the selective movement of leucocytes into inflammatory areas and they also activate various cells in inflamed tissues. However, it is unclear which cells are the main sources of chemokines in actual inflammatory diseases, even though both mononuclear cells and non-inflammatory resident cells are able to produce chemokines in vitro and the former cells are also the main target of chemokines. To clarify the roles of chemokines that are produced by mononuclear cells in AD, we measured levels in vivo of mRNA for IL-8 and MIP-1 alpha, as well as the level of regulated upon activation normal T cell expressed and secreted (RANTES) mRNA in freshly isolated peripheral blood mononuclear cells from patients with AD. We compared the results with those from psoriatic patients, and patients without AD who were suffering from other cutaneous diseases and eosinophilia. Levels of mRNAs were determined by semiquantitative reverse transcriptase-polymerase chain reactions. Levels of IL-8 and MIP-1 alpha mRNA were elevated not only in atopic patients but also in non-atopic patients with inflammatory skin disease associated with eosinophilia, compared with levels in psoriatic patients and healthy controls. Levels of RANTES mRNA were similar in atopic patients but they were lower in the other two groups of patients when compared with levels in healthy controls. In atopic patients, the levels of both IL-8 and MIP-1 alpha mRNAs but not of RANTES mRNA decreased with improvements in symptom scores after therapy. These findings suggest that mononuclear cells are not only the target of chemokines but might also play an important role in the pathogenesis of AD by producing IL-8 and MIP-1 alpha.