Overexpression of tumour necrosis factor-alpha-converting enzyme in psoriasis

The relationship between TNF-α, IL-1, IL-12, IL-17, IL-23, IL-36 expression and treatment response in psoriasis histopathologically and immunohistochemically

AIM

There is no marker that can predict whether there is resistance to treatment in patients with psoriasis. In this study, we investigated the relationship between the staining rates of TNF-α, IL-1, IL-12, IL-17, IL-23, and IL-36 markers immunohistochemically from cutaneous biopsy and the treatment success.

METHODS

The patients who were followed up in the dermatology clinic with the diagnosis of plaque-type psoriasis vulgaris and received biological treatment and previously had cutaneous biopsy were included in the study. The cutaneous biopsies of the cases that met the conditions were re-sectioned and subjected to immunohistochemical examination for TNF-α, IL-1, IL-12, IL-17, IL-23, and IL-36.

RESULTS

Comparing the staining scores with psoriasis area severity index (PASI); A statistically significant positive correlation was found between PASI and TNF-α staining score (p = 0.034). A statistically significant positive correlation was found between PASI and IL-17 staining score (p = 0.004). When the staining scores and PASI response rates of psoriasis treatment were evaluated in terms of correlation; there was a positive correlation between TNF-α, IL-17, and IL-23 immunohistochemical staining rates and PASI response rates.

CONCLUSIONS

In line with the data obtained from our study, we think that making immunohistochemical scoring before the biological treatment decision in psoriasis patients will be beneficial in treatment selection. In this respect, our study may open a new era in the selection of biological treatments for psoriasis.

The protease ADAM17 at the crossroads of disease: revisiting its significance in inflammation, cancer, and beyond

The protease A Disintegrin And Metalloproteinase 17 (ADAM17) plays a central role in the pathophysiology of several diseases. ADAM17 is involved in the cleavage and shedding of at least 80 known membrane-tethered proteins, which subsequently modulate several intracellular signaling pathways, and therefore alter cell behavior. Dysregulated expression and/or activation of ADAM17 has been linked to a wide range of autoimmune and inflammatory diseases, cancer, and cardiovascular disease. In this review, we provide an overview of the current state of knowledge from preclinical models and clinical data on the diverse pathophysiological roles of ADAM17, and discuss the mechanisms underlying ADAM17-mediated protein shedding and the potential therapeutic implications of targeting ADAM17 in these diseases.

Role of Metalloproteinases in Diabetes-associated Mild Cognitive Impairment

Diabetes has been linked to an increased risk of mild cognitive impairment (MCI), a condition characterized by a subtle cognitive decline that may precede the development of dementia. The underlying mechanisms connecting diabetes and MCI involve complex interactions between metabolic dysregulation, inflammation, and neurodegeneration. A critical mechanism implicated in diabetes and MCI is the activation of inflammatory pathways. Chronic low-grade inflammation, as observed in diabetes, can lead to the production of pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), interleukin-1 beta (IL-1β), and interferon-gamma (IFNγ), each of which can exacerbate neuroinflammation and contribute to cognitive decline. A crucial enzyme involved in regulating inflammation is ADAM17, a disintegrin, and metalloproteinase, which can cleave and release TNF-α from its membrane-bound precursor and cause it to become activated. These processes, in turn, activate additional inflammation-related pathways, such as AKT, NF-κB, NLP3, MAPK, and JAK-STAT pathways. Recent research has provided novel insights into the role of ADAM17 in diabetes and neurodegenerative diseases. ADAM17 is upregulated in both diabetes and Alzheimer's disease, suggesting a shared mechanism and implicating inflammation as a possible contributor to much broader forms of pathology and pointing to a possible link between inflammation and the emergence of MCI. This review provides an overview of the different roles of ADAM17 in diabetes-associated mild cognitive impairment diseases. It identifies mechanistic connections through which ADAM17 and associated pathways may influence the emergence of mild cognitive impairment.

Initial study of the detection of ADAM 10 in the urine of type-2 diabetic patients

Diabetes mellitus (DM) is a disease of civilization. If left untreated, it can cause serious complications and significantly shortens the life time. DM is one of the leading causes of end-stage renal disease (uremia) worldwide. Early diagnosis is a prerequisite for successful treatment, preferably before the first symptoms appear. In this paper, we describe the optimization and synthesis of the internally quenched fluorescent substrate disintegrin and metalloproteinase 10 (ADAM10). Using combinatorial chemistry methods with iterative deconvolution, the substrate specificity of the enzyme in non-primed and primed positions was determined. We used the ABZ-Lys-Ile-Ile-Asn-Leu-Lys-Arg-Tyr(3-NO2)-NH2 peptide to study ADAM10 activity in urine samples collected from patients diagnosed with type 2 diabetes, compared to urine samples from healthy volunteers. The proteolytically active enzyme was present in diabetes samples, while in the case of healthy people we did not observe any activity. In conclusion, our study provides a possible basis for further research into the potential role of ADAM10 in the diagnosis of type 2 diabetes.

Biomolecular interactions between the antibacterial ceftolozane and the human inflammatory disease target ADAM17: a drug repurposing study

Inhibition of a disintegrin and metalloproteinase-17 (ADAM17), a metzincin, is proposed as a novel therapeutic strategy to suppress overproduction of the proinflammatory cytokine TNF-α in rheumatoid arthritis and inflammatory bowel disease. Existing ADAM17 inhibitors generate toxic metabolites in-vivo or haven't progressed in clinical trials. Previous studies suggest that ligands which bind to ADAM17 active site by interacting with the Zn ion and L-shaped hydrophobic S1'- and S3'-pockets and forming favorable hydrogen bonds could act as potential ADAM17 inhibitors. Here, we investigated whether the FDA-approved anti-bacterial drug ceftolozane, a cephalosporin containing aromatic groups and carboxyl groups as probable zinc binding groups (ZBGs), forms non-covalent interactions resulting in its binding in the active site of ADAM17. In this study, the density functional theory (DFT), molecular docking and molecular dynamics calculations with the catalytic chain of ADAM17 show that carboxyl group of ceftolozane acts as moderate ZBG, and its extended geometry forms hydrogen bonds and hydrophobic interactions resulting in a binding affinity comparable to the co-crystallized known ADAM17 inhibitor. The favorable binding interactions identified here suggest the potential of ceftolozane to modulate ADAM17 activity in inflammatory diseases. ADAM17 cleaves and releases epidermal growth factor (EGF) ligands from the cell surface. The shed EGF ligands then bind to the EGF receptors to drive embryonic development. Therefore, our findings also suggest that use of ceftolozane during pregnancy may inhibit ADAM17-mediated shedding of EGF and thus increase the risk of birth defects in humans.Communicated by Ramaswamy H. Sarma.

Role of ADAM10 and ADAM17 in the Regulation of Keratinocyte Adhesion in Pemphigus Vulgaris

The severe autoimmune blistering disease Pemphigus vulgaris (PV) is mainly caused by autoantibodies (IgG) against desmoglein (Dsg) 3 and Dsg1. The mechanisms leading to the development of blisters are not fully understood, but intracellular signaling seems to play an important role. Sheddases ADAM10 and ADAM17 are involved in the turnover of the desmosomal cadherin Dsg2 and ADAM10 has been shown to contribute to acantholysis in a murine pemphigus model. In the present study, we further examined the role of ADAM10 and ADAM17 both in keratinocyte adhesion and in the pathogenesis of PV. First, we found that inhibition of ADAM10 enhanced adhesion of primary human keratinocytes but not of immortalized keratinocytes. In dissociation assays, inhibition of ADAM10 shifted keratinocyte adhesion towards a hyperadhesive state. However, ADAM inhibition did neither modulate protein levels of Dsg1 and Dsg3 nor activation of EGFR at Y1068 and Y845. In primary human keratinocytes, inhibition of ADAM10, but not ADAM17, reduced loss of cell adhesion and fragmentation of Dsg1 and Dsg3 immunostaining in response to a PV1-IgG from a mucocutaneous PV patient. Similarly, inhibition of ADAM10 in dissociation assay decreased fragmentation of primary keratinocytes induced by a monoclonal antibody against Dsg3 and by PV-IgG from two other patients both suffering from mucosal PV. However, such protective effect was not observed in both cultured cells and ex vivo disease models, when another mucocutaneous PV4-IgG containing more Dsg1 autoantibodies was used. Taken together, ADAM10 modulates both hyperadhesion and PV-IgG-induced loss of cell adhesion dependent on the autoantibody profile.

The importance of ADAM10 and ADAM17 metalloproteinases in the pathogenesis of psoriasis

BACKGROUND

Psoriasis is a chronic inflammatory skin disorder characterized by inflammation, hyperproliferation, andneoangiogenesis. The disease pathogenesis has not been fully elucidated. ADAM17 and ADAM10 are important proteases serving as regulators of inflammation.

OBJECTIVES

This study aimed to determine the role of ADAM17 and ADAM10 in the pathogenesis of Psoriasis through the comparison of serum ADAM17 and ADAM10 levels between Psoriasis patients and healthy controls.

METHODS

A total of 179 subjects, including 90 psoriasis patients and 89 healthy controls, were included in the study. Serum ADAM17 and serum ADAM10 levels were measured by the ELISA method for each participant from the patient and control groups. The statistical data analysis was performed using the SPSS 19.0 program. P-value < 0.05 was considered statistically significant.

RESULTS

The mean values for serum ADAM10 and ADAM17 were respectively 3.1±2.2 and 76.5±31.1 in the patient group, whereas 8.6±3.7 and 29.5±22.4 in the control group. A statistically significant difference was detected between the patient and control groups regarding ADAM10 and ADAM17 levels (p=0.0001).

CONCLUSIONS

Considering the high levels of ADAM17 in Psoriasis patient group, ADAM17 protease might have a crucial role in the pathogenesis of psoriasis, while the low levels of ADAM10 might be attributed to its regulatory effect on keratinocyte differentiation and proliferation.

ADAM Metalloproteinase Domain 17 Regulates Cholestasis-Associated Liver Injury and Sickness Behavior Development in Mice

Disintegrin and metalloproteinase domain-containing protein 17 (ADAM17) is a ubiquitously expressed membrane-bound enzyme that mediates shedding of a wide variety of important regulators in inflammation including cytokines and adhesion molecules. Hepatic expression of numerous cytokines and adhesion molecules are increased in cholestatic liver diseases including primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC), however, the pathophysiological role of ADAM17 in regulating these conditions remains unknown. Therefore, we evaluated the role of ADAM17 in a mouse model of cholestatic liver injury due to bile duct ligation (BDL). We found that BDL enhanced hepatic ADAM17 protein expression, paralleled by increased ADAM17 bioactivity. Moreover, inhibition of ADAM17 bioactivity with the specific inhibitor DPC 333 significantly improved both biochemical and histological evidence of liver damage in BDL mice. Patients with cholestatic liver disease commonly experience adverse behavioral symptoms, termed sickness behaviors. Similarly, BDL in mice induces reproducible sickness behavior development, driven by the upregulated expression of cytokines and adhesion molecules that are in turn regulated by ADAM17 activity. Indeed, inhibition of ADAM17 activity significantly ameliorated BDL-associated sickness behavior development. In translational studies, we evaluated changes in ADAM17 protein expression in liver biopsies obtained from patients with PBC and PSC, compared to normal control livers. PSC and PBC patients demonstrated increased hepatic ADAM17 expression in hepatocytes, cholangiocytes and in association with liver-infiltrating immune cells compared to normal controls. In summary, cholestatic liver injury in mice and humans is associated with increased hepatic ADAM17 expression. Furthermore, inhibition of ADAM17 activity improves both cholestatic liver injury and associated sickness behavior development, suggesting that ADAM17 inhibition may represent a novel therapeutic approach for treating patients with PBC/PSC.

Alcohol in Psoriasis-From Bench to Bedside

Alcohol affects the symptoms, compliance and comorbidities as well as the safety and efficacy of treatments in psoriatic patients. In this review, we aim to summarize and link clinical observations with a molecular background, such as signaling pathways at the cellular level and genetic variations, and to provide an overview of how this knowledge could influence our treatment selection and patient management.

Serum Krebs von den Lungen-6 levels in psoriatic patients under treatment with biologics

During biologic treatments, attention should be paid to adverse reactions, particularly infectious diseases. Furthermore, drug-induced interstitial lung disease is also known to be associated with biologic therapies. We retrospectively reviewed serum Krebs von den Lungen-6 (KL-6) levels in psoriatic patients who underwent treatment with seven different biologics. A total of 67 patients who received 80 biologic treatments were evaluated. The 31 anti-tumor necrosis factor (TNF)-α treatments consisted of 17 infliximab (IFX) and 14 adalimumab. The 23 anti-interleukin (IL)-23 treatments consisted of 14 ustekinumab and nine guselkumab. The 26 anti-IL-17 treatments consisted of nine secukinumab, six ixekizumab and 11 brodalumab. The IFX showed significantly increased mean serum KL-6 (170.9%), but none of the other treatments showed significant increases. Thirteen of the 17 (75.6%) patients in the IFX and 17 of the 31 (54.8%) patients in the total anti-TNF-α group demonstrated at least a 25% increase in serum KL-6. Levels exceeding the cut-off (500 U/mL) were detected in three patients before treatment and in seven patients after treatment. This study showed that anti-IL-17 and anti-IL-23 treatments have no significant impact on serum KL-6 level. In addition to the influence of IFX, a significantly large number of patients in the IFX group had a history of methotrexate administration associated with psoriatic arthritis, which might have influenced the KL-6 level. None of the patients with elevated serum KL-6 showed pulmonary changes by computed tomography and/or X ray.

Ab locks for improving the selectivity and safety of antibody drugs

Monoclonal antibodies (mAbs) are a major targeted therapy for malignancies, infectious diseases, autoimmune diseases, transplant rejection and chronic inflammatory diseases due to their antigen specificity and longer half-life than conventional drugs. However, long-term systemic antigen neutralization by mAbs may cause severe adverse events. Improving the selectivity of mAbs to distinguish target antigens at the disease site from normal healthy tissue and reducing severe adverse events caused by the mechanisms-of-action of mAbs is still a pressing need. Development of pro-antibodies (pro-Abs) by installing a protease-cleavable Ab lock is a novel and advanced recombinant Ab-based strategy that efficiently masks the antigen binding ability of mAbs in the normal state and selectively "turns on" the mAb activity when the pro-Ab reaches the proteolytic protease-overexpressed diseased tissue. In this review, we discuss the design and advantages/disadvantages of different Ab lock strategies, focusing particularly on spatial-hindrance-based and affinity peptide-based approaches. We expect that the development of different masking strategies for mAbs will benefit the local reactivity of mAbs at the disease site, increase the therapeutic efficacy and safety of long-term treatment with mAbs in chronic diseases and even permit scientists to develop Ab drugs for formerly undruggable targets and satisfy the unmet medical needs of mAb therapy.

Sirtuin 1 and endothelial glycocalyx

Sirtuin1 deficiency or reduced activity comprises one of the hallmarks of diseases as diverse as chronic cardiovascular, renal, and metabolic, some malignancies, and infections, as well as aging-associated diseases. In a mouse model of endothelium-limited defect in sirtuin 1 deacetylase activity, we found a dramatic reduction in the volume of endothelial glycocalyx. This was associated with the surge in the levels of one of key scaffolding heparan sulfate proteoglycans of endothelial glycocalyx, syndecan-4, and specifically, its extracellular domain (ectodomain). We found that the defect in endothelial sirtuin 1 deacetylase activity is associated with (a) elevated basal and stimulated levels of superoxide generation (via the FoxO1 over-acetylation mechanism) and (b) increased nuclear translocation of NF-kB (via p65 over-acetylation mechanism). These findings laid the foundation for the proposed novel function of sirtuin 1, namely, the maintenance of endothelial glycocalyx, particularly manifest in conditions associated with sirtuin 1 depletion. In the forthcoming review, we summarize the emerging conceptual framework of the enhanced glycocalyx degradation in the states of defective endothelial sirtuin 1 function, thus explaining a broad footprint of the syndrome of endothelial dysfunction, from impaired flow-induced nitric oxide production, deterrent leukocytes infiltration, increased endothelial permeability, coagulation, and pro-inflammatory changes to development of microvascular rarefaction and progression of an underlying disease.

Mouse models of psoriasis and their relevance

Psoriasis is an inflammatory skin disorder that includes dynamic interactions between the immune system and skin and is clinically characterized by keratinocyte proliferation and distinct inflammatory cell infiltrates. Cross-talk between keratinocytes and immunocytes is essential for the development of psoriasis given that it mediates the production of cytokines, chemokines and growth factors. To resolve the pathogenesis of psoriasis, numerous experimental animal models have been generated. In this review, we discuss recent findings from mouse models, their relevancy to psoriasis and use, including the discovery of new therapies.

Review of narrowband ultraviolet B radiation in vitiligo

Vitiligo is a common, acquired pigmentary disorder of unknown etiology with great impact on patient’s appearance and quality of life. It presents a therapeutic challenge to many dermatologists. Photochemotherapy using psoralen and ultraviolet A (UVA) therapy, topical and oral immunosuppresants, as well as cosmetic camouflage are also commonly employed with varying clinical efficacy. Phototherapy is a popular treatment option, which includes both of the generalized ultraviolet B (UVB) therapies, broadband UVB and narrowband UVB (NB-UVB). It has been used favorably, both alone as well as in combination with other agents like topical calcineurin inhibitors, vitamin-D analogs. Combination therapies are useful and may provide quicker regimentation and treat vitiligo with an additive mechanism of action than UVB phototherapy. Advances in technology may lead to the continuing use of UVB phototherapy as a treatment for vitiligo through the development of sophisticated devices and delivery systems as well as innovative application methods. These will provide increased therapeutic options for all vitiligo patients, particularly those with refractory disease. In this article, I have reviewed the available data pertaining to efficacy and safety issues for NB-UVB as monotherapy, its comparison with psoralen plus UVA and other modes of phototherapy, combination regimens that have been tried and future prospects of NB-UVB in vitiligo.

Psoriasis and the liver: problems, causes and course

BACKGROUND/OBJECTIVES

Psoriasis patients have a higher risk of liver abnormalities such as non-alcoholic fatty liver disease (NAFLD), drug-induced hepatitis, alcoholic hepatitis and neutrophilic cholangitis, than the general population. Associated liver disease limits therapeutic options and necessitates careful monitoring. The aim of the study was to identify liver problems in psoriasis patients and to investigate the underlying causes as well as their course.

METHODS

The files of 518 psoriasis patients were retrospectively reviewed. Among these, 393 patients with relevant laboratory data were analysed for liver enzymes and their relation to the known risk factors for liver disease (obesity, diabetes mellitus, alcohol consumption, hepatotoxic medications, dyslipidemia, psoriatic arthritis and infectious hepatitis).

RESULTS

Among 393 patients, 24% and 0.8% developed liver enzyme abnormalities and cirrhosis, respectively. The most common factors associated with pathological liver enzymes were drugs (57%) and NAFLD (22%). Other rare causes were alcoholic hepatitis, viral hepatitis, neutrophilic cholangitis, autoimmune hepatitis and toxic hepatitis due to herbal therapy. Drug-induced liver enzyme abnormalities were reversible whereas in patients with NAFLD transaminases tended to fluctuate. One patient with herbal medicine-related cirrhosis died of sepsis.

CONCLUSION

Liver enzyme abnormalities are common in psoriasis patients and are mostly associated with drugs and NAFLD. Although most cases can be managed by avoiding hepatotoxic medications and close follow up, severe consequences like cirrhosis may develop.

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.

Alcohol intake and risk of incident psoriatic arthritis in women

OBJECTIVE

Alcohol intake has been associated with an increased risk of psoriasis. However, the association between alcohol intake and risk of psoriatic arthritis (PsA) has been unclear. We evaluated the association between alcohol intake and risk of incident PsA in a large cohort of US women.

METHODS

Our present study included a total of 82,672 US women who provided repeated data on alcohol intake over the followup period (1991-2005). Self-reported PsA was validated using the Psoriatic Arthritis Screening and Evaluation (PASE) questionnaire. Cox proportional hazards models were used to estimate the age-adjusted and multivariate-adjusted HR and 95% CI for the PsA in association with alcohol intake.

RESULTS

We documented 141 incident PsA cases during 14 years (1,137,763 person-yrs) of followup. Compared to non-drinkers, the multivariate HR for PsA were 0.70 (95% CI 0.48-1.01) for 0.1-14.9 g/day, 1.43 (95% CI 0.67-3.08) for 15.0-29.9 g/day, and 4.45 (95% CI 2.07-9.59) for ≥ 30.0 g/day of cumulative average alcohol intake. Risk estimates were generally consistent when using updated alcohol intake and baseline alcohol intake in 1991 as the exposures, and when the analysis was restricted to those who developed psoriasis during the followup.

CONCLUSION

Excessive alcohol intake was associated with an increased risk of incident PsA in a cohort of US women.

Involvement of TNF-α converting enzyme in the development of psoriasis-like lesions in a mouse model

TNF-α plays a crucial role in psoriasis; therefore, TNF inhibition has become a gold standard for the treatment of psoriasis. TNF-α is processed from a membrane-bound form by TNF-α converting enzyme (TACE) to soluble form, which exerts a number of biological activities. EGF receptor (EGFR) ligands, including heparin-binding EGF-like growth factor (HB-EGF), amphiregulin and transforming growth factor (TGF)-α are also TACE substrates and are psoriasis-associated growth factors. Vascular endothelial growth factor (VEGF), one of the downstream molecules of EGFR and TNF signaling, plays a key role in angiogenesis for developing psoriasis. In the present study, to assess the possible role of TACE in the pathogenesis of psoriasis, we investigated the involvement of TACE in TPA-induced psoriasis-like lesions in K5.Stat3C mice, which represent a mouse model of psoriasis. In this mouse model, TNF-α, amphiregulin, HB-EGF and TGF-α were significantly up-regulated in the skin lesions, similar to human psoriasis. Treatment of K5.Stat3C mice with TNF-α or EGFR inhibitors attenuated the skin lesions, suggesting the roles of TACE substrates in psoriasis. Furthermore, the skin lesions of K5.Stat3C mice showed down-regulation of tissue inhibitor of metalloproteinase-3, an endogenous inhibitor of TACE, and an increase in soluble TNF-α. A TACE inhibitor abrogated EGFR ligand-dependent keratinocyte proliferation and VEGF production in vitro, suggesting that TACE was involved in both epidermal hyperplasia and angiogenesis during psoriasis development. These results strongly suggest that TACE contributes to the development of psoriatic lesions through releasing two kinds of psoriasis mediators, TNF-α and EGFR ligands. Therefore, TACE could be a potential therapeutic target for the treatment of psoriasis.

Inflammation and Its Correlates in Regenerative Wound Healing: An Alternate Perspective

Objective: The wound healing response may be viewed as partially overlapping sets of two physiological processes, regeneration and wound repair with the former overrepresented in some lower species such as newts and the latter more typical of mammals. A robust and quantitative model of regenerative healing has been described in Murphy Roths Large (MRL) mice in which through-and-through ear hole wounds in the ear pinna leads to scarless healing and replacement of all tissue through blastema formation and including cartilage. Since these mice are naturally autoimmune and display many aspects of an enhanced inflammatory response, we chose to examine the inflammatory status during regenerative ear hole closure and observed that inflammation has a clear positive effect on regenerative healing. Approach: The inflammatory gene expression patterns (Illumina microarrays) of early healing ear tissue from regenerative MRL and nonregenerative C57BL/6 (B6) strains are presented along with a survey of innate inflammatory cells found in this tissue type pre and postinjury. The role of inflammation on healing is tested using a COX-2 inhibitor. Innovation and Conclusion: We conclude that (1) enhanced inflammation is consistent with, and probably necessary, for a full regenerative response and (2) the inflammatory gene expression and cell distribution patterns suggest a novel mast cell population with markers found in both immature and mature mast cells that may be a key component of regeneration.

ADAM17 at the interface between inflammation and autoimmunity

The discovery of the disintegrin and metalloproteinase 17 (ADAM17), originally identified as tumor necrosis factor-a converting enzyme (TACE) for its ability as sheddase of TNF-α inspired scientists to attempt to elucidate the molecular mechanisms underlying ADAM17 implication in diseased conditions. In recent years, it has become evident that this protease can modify many non matrix substrates, such as cytokines (e.g. TNF-α), cytokine receptors (e.g. IL-6R and TNF-R), ligands of ErbB (e.g. TGF-α and amphiregulin) and adhesion proteins (e.g. Lselectin and ICAM-1). Several recent studies have described experimental model system to better understand the role of specific signaling molecules, the interplay of different signals and tissue interactions in regulating ADAM17-dependent cleavage of most relevant substrates in inflammatory diseases. The central question is whether ADAM17 can influence the outcome of inflammation and if so, how it performs this regulation in autoimmunity, since inflammatory autoimmune diseases are often characterized by deregulated metalloproteinase activities. This review will explore the latest research on the influence of ADAM17 on the progression of inflammatory processes linked to autoimmunity and its role as modulator of inflammation.

Matrix metalloproteinases and their role in psoriasis

This review summarizes the contribution of matrix metalloproteinases to the pathogenesis of psoriasis. In psoriasis, matrix metalloproteinases are involved in the structural changes of the epidermis via the modification of intracellular contacts and the composition of the extracellular matrix, promoting angiogenesis in the dermal blood vessels and the infiltration of immune cells. Moreover, some matrix metalloproteinases become differentially expressed during the disease eruption and their expression correlates with the clinical score. A separate section of the review is dedicated to the pharmacological approaches that are used to control matrix metalloproteinases, such as oral metalloproteinase inhibitors, such as azasugars and phosphonamides. The aim of this manuscript is to assess the role of matrix metalloproteinases in the physiological processes that accompany the disease. Moreover, it is especially important to evaluate progress in this field and characterize recently appeared medicines. Because any experimental drugs that target matrix metalloproteinases are involved in active clinical trials, this manuscript also reviews the latest experimental data regarding distribution and expression of matrix metalloproteinases in healthy skin and lesional skin. Therefore, the performed analysis highlights potential problems associated with the use of metalloproteinase inhibitors in clinical studies and suggests simple and easy understandable criteria that future innovative metalloproteinase inhibitors shall satisfy.

Expression of disintegrin and metalloproteinase family proteins 10, 12 and 17 in cholesteatoma

Objective:

Proteases of the disintegrin and metalloproteinase family (also known as ADAM proteins) are involved in various physiological and pathological processes. This study assessed the expression of disintegrin and metalloproteinase family proteins 10, 12 and 17 in cholesteatoma.

Materials and methods:

The study evaluated cholesteatoma specimens from 19 patients, and external ear canal skin samples from 7 of the same patients (as controls), for the expression of disintegrin and metalloproteinase family proteins 10, 12 and 17, using immunohistochemical methods.

Results and analysis:

The study observed over-expression of proteins 10 and 17 in blood vessels, and over-expression of proteins 12 and 17 in cholesteatoma stroma. Immunostaining scores for proteins 10, 12 and 17 in epithelial and inflammatory cells from cholesteatoma specimens versus control specimens showed no statistically significant differences.

Conclusion:

Over-expression of disintegrin and metalloproteinase family proteins 10, 12 and 17 in cholesteatoma may be related to cholesteatoma pathogenesis. These proteins deserve further study as they may represent potential targets for cholesteatoma treatment.

Over-expression of tumor necrosis factor-α in vitiligo lesions after narrow-band UVB therapy: an immunohistochemical study

There is a growing evidence that cytokines are important in the depigmentation process of vitiligo, however, the exact mechanism is not fully understood. The aim of this work was to study the possible role of the tumor necrosis factor-α (TNF-α) cytokine in the depigmentation process of the disease. Twenty patients with generalized vitiligo were exposed to narrow-band ultraviolet B (NB-UVB) therapy thrice weekly for a total of 60 sessions. Immunohistochemical examination was done, to assess the TNF-α expression in lesional and perilesional skin as compared to normal control skin, before and after therapy. At baseline, positive lesional TNF-α expression was detected in 60 % of patients which was significantly higher as compared to perilesional skin (20 %) and negative expression in healthy control skin. Post-treatment, a statistically significant increase in TNF-α expression was detected in both lesional (90 %) and perilesional skin (70 %) as compared to baseline (P < 0.05). The significant increase of TNF-α in vitiligo lesions compared with perilesional and healthy skin suggests a possible involvement of this cytokine in the depigmentation of vitiligo. The increase in TNF-α expression after NB-UVB phototherapy suggests another role in repigmentation.

Tumor necrosis factor α release in peripheral blood mononuclear cells of cutaneous lupus and dermatomyositis patients

Introduction

Several studies have reported that TNFα is substantially increased within skin lesions of patients with discoid lupus erythematosus (DLE), subacute cutaneous lupus erythematosus (SCLE) and dermatomyositis (DM) compared to controls. Elevated TNFα has been reported in the sera of some patients with systemic lupus erythematosus, DLE and SCLE, but not in the sera of patients with DM. Because of the key pathogenic role of autoimmunity in these diseases, in this study we sought to evaluate TNFα production by a readily available source of immune cells (namely, peripheral blood mononuclear cells (PBMCs)) taken from controls and from patients with cutaneous lupus or DM.

Methods

Freshly isolated PBMCs were cultured overnight, and TNFα protein accumulation in conditioned medium was determined. In addition, flow cytometry using cell-type-specific markers was performed to determine the sources of TNFα. One-way analysis of variance and Dunnett's multiple comparisons test were performed for statistical comparisons.

Results

Accumulation of TNFα protein in conditioned medium containing PBMCs from DLE patients, but not from SCLE, TLE or DM patients, was significantly greater (19-fold) than that from controls (P < 0.001). In DLE PBMCs, increased TNFα was produced by circulating monocytes and myeloid dendritic cells (mDCs). The mean TNFα fluorescence intensity, but not the total number, of both monocytes and mDCs (P < 0.01) from DLE patients was significantly greater (2.3-fold) than that of controls. There were significantly more (13.3-fold) mDCs with intracellular TNFα in blood from DLE patients (P < 0.001) and DM patients (P < 0.001) compared to controls. Most importantly, a positive correlation was seen in DLE patients between their disease activity measured using the Cutaneous Lupus Erythematosus Disease Area and Severity Index and TNFα protein secretion (r = 0.61, P < 0.08).

Conclusions

TNFα protein production by PBMCs is greater in DLE patients than in patients with other cutaneous forms of lupus and DM or in controls. Flow cytometric studies demonstrated that circulating monocytes and mDCs contributed to this increased TNFα production. Monocytes and mDCs are present in lesional skin, and the increased TNFα production by these cells and other PBMCs likely increase the number of inflammatory cells seen in DLE skin relative to other subsets of cutaneous lupus erythematosus and DM. These results provide a possible biological explanation for the denser infiltrate seen in DLE relative to DM.

Anti-tumor necrosis factor treatment in occult hepatitis B virus infection: a retrospective analysis of 62 patients with psoriatic disease

One of the problems possibly related to the use of biological agents targeting tumor necrosis factor (TNF)-alpha is the increased risk of infections, including the activation of hepatitis B virus (HBV). HBV activation can occur in carriers of hepatitis B surface antigen (HBsAg), but the risk may also involve the HBsAg-negative (anti-HBc ± anti-HBs) occult carriers. Precise data on the safety of anti-TNF and/or other immunosuppressive drugs in HBV occult carriers are not available. We performed a retrospective analysis of 62 psoriatic patients with occult HBV infection treated with anti-TNF biological agents over a period of approximately 4 years: 44 subjects were treated with etanercept, 8 with infliximab and 10 with adalimumab. During the observational treatment period, no signs of HBV activation were observed. Only in one patient the reappearance of HBsAg, without detectable HBV-DNA, was noted before retreatment with etanercept and after 10 months from discontinuation of the previous course. In this patient etanercept was re-administered in association with lamivudine without any adverse event. Our results suggest the overall safety of treatment with anti-TNF drugs in HBV occult carriers, although a careful and constant monitoring of virological markers is required in such patients during treatment with anti-TNF drugs in order to have an early recognition of viral reactivation.

The Roles of ADAMs Family Proteinases in Skin Diseases

A disintegrin and metalloproteinases (ADAMs) are members of a new gene family of transmembrane and secreted proteins, which belong to the zinc proteinase superfamily. These molecules are involved in various biological events such as cell adhesion, cell fusion, cell migration, membrane protein shedding, and proteolysis. Growing evidence now attests to the potential involvement of ADAMs proteinases in diverse processes such as skin wound healing, inflammation, pigmentation, tumor development, cell proliferation, and metastasis. This paper focuses on the roles of ADAMs proteinases in a wide variety of skin diseases.

ADAM-17: the enzyme that does it all

This review focuses on the role of ADAM-17 in disease. Since its debut as the tumor necrosis factor converting enzyme (TACE), ADAM-17 has been reported to be an indispensible regulator of almost every cellular event from proliferation to migration. The central role of ADAM-17 in cell regulation is rooted in its diverse array of substrates: cytokines, growth factors, and their receptors as well as adhesion molecules are activated or inactivated by their cleavage with ADAM-17. It is therefore not surprising that ADAM-17 is implicated in numerous human diseases including cancer, heart disease, diabetes, rheumatoid arthritis, kidney fibrosis, Alzheimer's disease, and is a promising target for future treatments. The specific role of ADAM-17 in the pathophysiology of these diseases is very complex and depends on the cellular context. To exploit the therapeutic potential of ADAM-17, it is important to understand how its activity is regulated and how specific organs and cells can be targeted to inactivate or activate the enzyme.

Tumor necrosis factor-alpha-converting enzyme as a potential mediator of the influence of smoking on the response to treatment with narrowband ultraviolet B in psoriasis patients

PURPOSE

The aim of the study was to analyze the relationship between smoking and the treatment with narrowband ultraviolet B (NB-UVB) in psoriasis patients and to examine the role of the soluble tumor necrosis factor-alpha receptor type one (sTNF-R1) in plasma and that of TNF-alpha-converting enzyme (TACE) released from peripheral blood mononuclear cells (PBMC) in this relationship.

METHODS

The study has been conducted among 45 inpatients with plaque-type psoriasis vulgaris and 36 inpatients with other chronic inflammatory skin disorders from similar social background (controls). Taking into account the number of cigarettes smoked daily and the duration of smoking, subjects were classified as mild, moderate and heavy smokers. The severity of psoriasis was assessed using psoriasis area and severity index (PASI) score, concentrations of sTNF-R1 and TACE (expressed in ng/ml)--with quantitative sandwich enzyme immunoassays before (T(0)) and after 20 NB-UVB irradiations (T(20)).

RESULTS

The pretreatment concentration of sTNF-R1 was 2.55+/-0.17 in patients and 1.79+/-0.13 in controls (P<0.05) and that of TACE - 2.62+/-0.34 and 1.29+/-0.25, P<0.05, respectively. PASI score correlated with sTNF-R1 and with TACE concentrations (R=0.40 and R=0.38, P<0.05, respectively). PASI score, sTNF-R1 and TACE concentrations were similar in mild, moderate and in heavy smokers. PASI score and TACE concentration declined significantly after treatment in three groups; the lowest TACE concentration at T(20) was noticed in mild smokers, the highest in heavy smokers (0.86+/-0.26 and 1.91+/-0.20, P<0.05, respectively). The post-treatment PASI score correlated with the intensity of smoking and with TACE concentration (R=0.50 and R=0.47, P<0.05, respectively). The strong correlation between the pretreatment TACE concentration and the treatment outcome was observed in heavy smokers (R=0.63, P<0.05).

CONCLUSIONS

The baseline TACE concentration in PBMC may be of value in predicting the response to the treatment with NB-UVB in smoking psoriasis patients. Smoking may adversely influence this treatment and TACE may be one of mediators in this influence.

Infliximab and insulin resistance

Insulin resistance is the most important pathophysiologic feature of obesity, type 2 diabetes mellitus and prediabetic states. TNF-alpha, a proinflammatory cytokine, plays a pivotal role in the pathogenesis of inflammation-associated insulin resistance during the course of rheumatic diseases. Therapies aimed at neutralizing TNF-alpha, such as the monoclonal antibody infliximab, represent a novel approach for the treatment of rheumatic diseases and allow to obtain significant results in terms of control of the inflammatory process. In this article we reviewed the scientific evidence published in the literature about a potential role of TNF-alpha blockade in improving insulin resistance in non-diabetic rheumatic patients.

Psoriasis and alcohol: is cutaneous ethanol one of the missing links?

Many exogenous factors including excessive alcohol consumption have been associated with psoriasis, but the underlying mechanisms still remain elusive. Drinking worsens therapeutic compliance, and decreases the efficacy and increases the toxicity of systemic antipsoriatic treatments. Excess alcohol intake results in compromised immunity and increased risk of infections, but alcohol can induce proinflammatory cytokine production in various cell types and can increase mitogen-derived lymphocyte proliferation and lymphocyte activation. As we have previously reported, alcohol and one of its metabolites, acetone, induce keratinocyte proliferation and increase the mRNA levels of genes characteristic for proliferating keratinocytes, such as alpha5 integrin, cyclin D1 and keratinocyte growth factor receptor. Recently the correlation between blood and skin ethanol levels in humans was determined by a transdermal alcohol monitoring device, against the 'gold standard' breath alcohol readings. Based on transdermal alcohol measurements it can be concluded that cutaneous alcohol concentrations can reach levels that induce proinflammatory cytokine production and lymphocyte and keratinocyte proliferation in vitro. It is expected that the development of methodologies measuring transdermal ethanol will provide additional tools to evaluate how alcohol influences skin physiology and different dermatological conditions including psoriasis. Our review focuses on the possible link between alcohol misuse and psoriasis, particularly on the possible role of cutaneous ethanol in precipitating the disease.

TNFα and its Receptors in Psoriatic Skin, before and after Treatment with Etanercept

Psoriasis is a chronic inflammatory skin condition characterized by inflammatory dermal infiltrate and hyperproliferative keratinocytes. The pathogenesis of this disease is mediated by a dysregulation of the innate immunity and cytokine production. Tumor Necrosis Factor alpha (TNFα) is considered the most important cytokine involved in the pathological mechanism of psoriasis. Recently, several therapies have been introduced for the treatment of psoriasis that try to block TNF alpha activity. Among these treatments Etanercept is a fusion protein that specifically targets TNF alpha. We performed a study on twelve psoriatic patients aimed at evaluating the effect of Etanercept treatment on the production and expression of TNFα and its receptors, in lesional and uninvolved psoriatic skin. We demonstrated that after three month of Etanercept treatment at 50 mg/wk, TNF, TNF-RI and TNF-RII immunostaining in lesional and non-lesional skin samples of patients was greatly reduced, suggesting that this treatment not only acts on stable lesional plaques, but also at a very early stage of the disease.

Polymorphisms in the tumor necrosis factor/lipopolysaccharides pathway in Crohn disease in the Jewish Ashkenazi population

OBJECTIVE

Tumor necrosis factor (TNF)-alpha plays a role in the inflammatory process in Crohn disease, a disease with an apparent polygenic basis. We investigated whether polymorphisms in multiple genes involved in the lipopolysaccharide-TNF inflammatory pathway are independently associated with Crohn disease in the Jewish Ashkenazi population. Polymorphisms in CD14, Toll-like receptor 4 (TLR4), and TNF-alpha were studied. In addition, we investigated polymorphisms in the TNF-alpha converting enzyme (TACE) gene, which to date has not been studied for an association with Crohn disease.

PATIENTS AND METHODS

To examine whether TLR4 Asp299Gly, CD14-260C/T, TNF-1031T/C, TNF-863C/A, TNF-857C/T, TACE-172C/T, and TACE-154C/A polymorphisms are associated with Crohn disease in the Ashkenazi Jewish population, we analyzed families with at least 1 child with Crohn disease for association with these mutations using a family-based association test (transmission disequilibrium test) for analysis.

RESULTS

The allelic frequency in the patient population of TLR4 G allele was 8.0%, CD14 T allele was 51.3%, TNF-1031C was 18.8%, TNF-863A was 14.2%, TNF-857T was 25.2%, TACE172T was 20.7%, and TACE154A was 24.5%. The transmission disequilibrium test transmitted:untransmitted (T:U) result for TLR4G was T:U = 32:20, for CD14T was T:U = 103:88, for TNF-1031C was T:U = 48:56, for TNF-863A was T:U = 39:42, for TNF-857T was T:U = 63:62, for TACE-172C/T was T:U = 48:59, and for TACE-154C/A was T:U = 52:55. No statistically significant associations were observed.

CONCLUSIONS

The transmission disequilibrium test did not demonstrate preferential transmission of these variants in Jewish Ashkenazi patients with Crohn disease. These results suggest that these polymorphisms in the TNF/lipopolysaccharide pathway play little or no role in susceptibility to Crohn disease in the Jewish Ashkenazi population.

Tumour necrosis factor (TNF-alpha) alpha converting enzyme and soluble TNF-alpha receptor type 1 in psoriasis patients in relation to the chronic alcohol consumption

BACKGROUND

Tumour necrosis factor alpha converting enzyme (TACE) is a major sheddase of TNF-alpha and its receptors, essential for the generation of soluble, mature molecules. The regulation of the TACE activity by ethanol in vitro has been suggested recently. The alcohol abuse is a frequent problem among psoriasis patients. The aim of the study was to analyse the relationship between long-term alcohol consumption and the concentration of TACE in peripheral blood mononuclear cells (PBMC) and its substrate--soluble TNF-alpha receptor type 1 (sTNF-R1) in plasma in psoriasis patients.

METHODS

The study has been conducted among 44 patients (aged 30-59 years) with early-onset, plaque-type psoriasis. Thirty-eight patients (aged 29-61 years) with other than psoriasis chronic dermatologic disorders were controls. The data on alcohol consumption during previous 10 years were obtained with a structured questionnaire. The severity of the disease was assessed using Psoriasis Area and Severity Index (PASI), and concentrations of TACE in PBMC lysate and sTNF-R1 in plasma was assessed with a quantitative sandwich enzyme immunoassay technique.

RESULTS

The TACE concentration correlated to that of sTNF-R1 (R = 0.52 in psoriasis patients and R = 0.56 in controls, P < 0.05). The concentrations of TACE were 2.62 +/- 0.32 ng/mL in patients and 1.29 +/- 0.25 ng/mL in controls (P < 0.05), and corresponding sTNF-R1 concentrations were 2.54 +/- 0.27 ng/mL and 1.79 +/- 0.14 ng/mL (P < 0.05), respectively. The concentrations of TACE and sTNF-R1 in patients correlated to the intensity of alcohol consumption (R = 0.56, and R = 0.52, P < 0.05, respectively) and were the highest in excessive drinking psoriasis patients (2.94 +/- 0.34 and 2.67 +/- 0.13 ng/mL).

CONCLUSION

The alcohol abuse may contribute to the increase of TACE expression in PBMC and also to the elevated plasma sTNF-R1 concentration in psoriasis patients.

Tumour necrosis factor alpha (TNF-alpha)-converting enzyme (TACE) and soluble TNF-alpha receptor type 1 in psoriasis patients treated with narrowband ultraviolet B

PURPOSE

The aim of the study was to examine the tumour necrosis factor alpha (TNF-alpha)-converting enzyme (TACE) concentration in peripheral blood mononuclear cells (PBMC) and its relationship with plasma concentration of soluble TNF-alpha receptor type 1 (sTNF-R1) and with the disease severity in psoriasis patients treated with narrowband ultraviolet B (NB-UVB).

METHODS

The study has been conducted among 40 patients with plaque-type psoriasis vulgaris: 23 had only skin lesions (PV) and 17 had co-existing, inactive, psoriatic arthritis (PsA). Control blood samples were obtained from 20 healthy subjects. The assessment of the severity of skin lesions (using Psoriasis Area and Severity Index - PASI), TACE and sTNF-R1 concentrations (using quantitative sandwich enzyme immunoassays) have been performed at baseline (T 0) and after 20 NB-UVB irradiations (T 20).

RESULTS

The baseline sTNF-R1 and TACE concentrations in all patients was higher than that in controls (2.55 +/- 1.67 vs. 1.70 +/- 0.15 ng/ml, P<0.001, respectively, and 2.62 +/- 0.32 vs. 1.31 +/- 0.30 ng/ml, P<0.001, respectively). The sTNF-R1 and TACE concentrations were lower in PV than in PsA patients (2.47 +/- 0.16 vs. 2.65 +/- 0.13 ng/ml, and 2.52 +/- 0.22 vs. 2.76 +/- 0.39 ng/ml, P<0.05, respectively). The baseline PASI correlated with sTNF-R1 and to TACE concentrations (R=0.48 and 0.39, P<0.05, respectively). The sTNF-R1 correlated to TACE concentration (R=0.52, P<0.05). The significant decline in sTNF-R1 and TACE concentrations at T 20 was noticed, TACE reached control values (1.20 +/- 0.44 ng/ml in PV patients and 1.16 +/- 0.48 ng/ml in PsA patients, respectively).

CONCLUSION

TACE from PBMC can contribute to up-regulation of sTNF-R1 in patients with active psoriasis vulgaris and with psoriatic arthritis. It also can serve as a sensitive marker of the disease severity.

Heart Rate and Arrhythmia in Patients with Psoriasis Vulgaris

BACKGROUND

Psoriasis is a chronic inflammatory disease involving 1-3% of the human population worldwide. Many systemic diseases including cardiovascular disturbances have been described in psoriatic patients. However, there is a scarcity of data on heart rate, heart rate variability, arrhythmia and conduction abnormalities in this group of patients.

METHODS

The study comprised 32 patients with chronic psoriasis vulgaris and negative personal history of heart problems. Severity of the disease was evaluated by Psoriasis Area and Severity Index (PASI). Twenty-four-h continuous electrocardiographic monitoring (24-h Holter ECG) was performed in all patients.

RESULTS

Heart rate was significantly higher both during the day and at night in patients with psoriasis vulgaris than in the control group (p < 0.0001). There was a positive correlation between the increased heat rate, both during the day and at night, in psoriatic patients and severity of the disease expressed as PASI. Single supraventricular beats were significantly more frequently observed in psoriatic patients vs. the control group (p < 0.0001).

CONCLUSIONS

An active inflammatory process observed in psoriasis seems to exert its influence on increased heart rate and supraventricular beats development. However, to confirm the above findings, further studies on larger groups of psoriatic patients, presenting different types of the disease are mandatory.

Emerging drugs for psoriasis

Psoriasis is a chronic immune-mediated inflammatory skin disease characterised by abnormal keratinocyte differentiation and proliferation. The immunopathogenesis is complex and novel evidence shows the involvement of both innate and adaptive immune response. Type 1 T cells and their effector cytokines play a pivotal role. Several drugs under preclinical and clinical development for psoriasis are directed against the immune response, targeting activation or proliferation of T cells, their trafficking and skin-homing, or effector cytokines. Among these, great attention has been given to TNF-alpha, following the demonstration of effectiveness of anti-TNF-alpha biologicals, and to IFN-gamma inducers. Another appealing approach concerns drugs capable of inducing immunological tolerance. Progress made in the recognition of intracellular events has prompted the development of small molecules and oligonucleotides that can inhibit specific molecular targets. There is, however, a plethora of other emerging drugs, clearly suggestive of the current interest for psoriasis, which are briefly described in this paper.

An Analysis of Select Pathogenic Messages in Lesional and Non-Lesional Psoriatic Skin Using Non-Invasive Tape Harvesting

We report the use of non-invasive tape stripping to sample psoriatic lesional and non-lesional skin in 96 patients. The procedure was well tolerated with any discomfort described as mild; we did not observe any cases of Koebner phenomena at any non-lesional tape-stripped sites. Tape-harvested epidermis was extracted for RNA, which was profiled by semiquantitative reverse transcriptase-PCR. This analysis revealed that mRNAs for tumor necrosis factor alpha, IFNgamma, Krt-16, CD2, IL-23A, IL-12B, and vascular endothelial growth factor are overexpressed in the "average" psoriatic lesion in a majority of patients. In addition, 10 of these patients were biopsied at lesional and non-lesional sites and the expression data compared to tape-stripping data. This comparison shows that five of seven mRNA are more highly expressed in cells captured by tape stripping than biopsy, suggesting that the upper aspect of a lesion contains cells very active in the disease. The tape-harvesting data reveal that approximately 46% of lesions have at least one pathogenic mRNA within non-lesional skin limits. Data demonstrate that tape stripping reveals mRNA markers not detected in biopsy samples and thus the method may be a useful supplement to biopsy.

Soluble human p55 and p75 tumor necrosis factor receptors reverse spontaneous arthritis in transgenic mice expressing transmembrane tumor necrosis factor α

OBJECTIVE

The roles of the transmembrane and secreted forms of tumor necrosis factor alpha (TNFalpha) in rheumatoid arthritis (RA) remain unclear. Agents used to inhibit TNFalpha have shown varying efficacy in RA patients, suggesting that anti-TNFalpha agents possess dissimilar mechanisms of action, including the ability to neutralize transmembrane (tmTNFalpha) and secreted TNFalpha. In this study, TNFalpha-knockout (TNFalpha-KO) mice that were genetically altered to express elevated levels of tmTNFalpha were constructed to further understand the roles of the 17-kd secreted, trimeric, and 26-kd transmembrane forms of TNFalpha.

METHODS

A speed-congenic mating scheme was used to generate 3 unique strains of mice: 1) transgenic tmTgA86 mice overexpressing 26-kd tmTNFalpha and also secreting 17-kd trimeric TNFalpha (tmTNFalpha-transgenic), 2) TNFalpha-/- mice (TNFalpha-KO), and 3) transgenic mice overexpressing tmTNFalpha backcrossed to TNFalpha-KO mice (tmTNFalpha-transgenic/TNFalpha-KO). Mice were treated with phosphate buffered saline (as vehicle control), dexamethasone (as positive control), or modified recombinant human soluble TNF receptor (sTNFR) p55 or p75, and were assessed clinically and histopathologically for signs of inflammation and development of arthritis.

RESULTS

The tmTNFalpha-transgenic/TNFalpha-KO mice were born with crinkled tails and spinal deformities similar to those in ankylosing spondylitis. By 2-4 weeks, these mice developed symmetric inflammatory arthritis, characterized by tissue swelling, pannus formation, and bone deformities. The tmTNFalpha-transgenic mice also developed spontaneous-onset arthritis, but at a slower rate (100% incidence by 10-12 weeks). Clinical and histologic progression of arthritis in the tmTNFalpha-transgenic/TNFalpha-KO mice was reduced by treatment with dexamethasone or with the p55 or p75 sTNFR (69% and 63% reduction in total histologic score, respectively).

CONCLUSION

These data show that arthritis is sufficiently initiated and maintained in tmTNFalpha-transgenic/TNFalpha-KO mice, and that it can be neutralized by recombinant human p55 or p75 sTNFR, resulting in amelioration of the biologic and subsequent histologic destructive effects of tmTNFalpha.

The RATIO observatory: French registry of opportunistic infections, severe bacterial infections, and lymphomas complicating anti-TnFα therapy

The RATIO observatory collects nationwide data on opportunistic infections, severe bacterial infections, and lymphomas in patients with a past or present history of tumor necrosis factor alpha (TNFalpha) antagonist treatment in France. The cases are validated by a committee of experts, and the capture-recapture method is used to check and to improve case ascertainment. A nested case-control comparison is carried out to identify risk factors for the events of interest. The registry differs from other biological registries in that the inclusion criterion is occurrence of the event (infection or lymphoma) instead of administration of the treatment. This method ensures collection of a far larger number of cases. The RATIO observatory is a remarkable example of a three-way partnership of learned societies, pharmaceutical companies, and institutions (the French research institute INSERM and the French drug safety agency AFSSAPS). Over 100 events were reported in the first 16 months, a large increase compared to European registries of fixed patient cohorts monitored for 4-5 years. This result validates our original approach, which will probably need to be extended to other biotherapies for inflammatory joint disease and to other potential adverse events. The strong commitment of rheumatologists in France, who are the main prescribers of TNFalpha antagonists, and of the French Society for Rheumatology explain the high case-ascertainment and must continue to ensure that answers are rapidly provided to the drug safety questions that are vital to our patients.