Cross-regulation of TNF and IFN-alpha in autoimmune diseases

Nuclear receptors in inflammation control: repression by GR and beyond

Inflammation is a protective response of organisms to pathogens, irritation or injury. Primary inflammatory sensors activate an array of signaling pathways that ultimately converge upon a few transcription factors such as AP1, NFκB and STATs that in turn stimulate expression of inflammatory genes to ultimately eradicate infection and repair the damage. A disturbed balance between activation and inhibition of inflammatory pathways can set the stage for chronic inflammation which is increasingly recognized as a key pathogenic component of autoimmune, metabolic, cardiovascular and neurodegenerative disorders. Nuclear receptors (NRs) are a large family of transcription factors many of which are known for their potent anti-inflammatory actions. Activated by small lipophilic ligands, NRs interact with a wide range of transcription factors, cofactors and chromatin-modifying enzymes, assembling numerous cell- and tissue-specific DNA-protein transcriptional regulatory complexes with diverse activities. Here we discuss established and emerging roles and mechanisms by which NRs and, in particular, the glucocorticoid receptor (GR) repress genes encoding cytokines, chemokines and other pro-inflammatory mediators.

Dermatological adverse reactions during anti-TNF treatments: focus on inflammatory bowel disease

The clinical introduction of tumour necrosis factor (TNF) inhibitors has deeply changed the treatment of inflammatory bowel diseases (IBD). It has demonstrated impressive efficacy as compared to alternative treatments, allowing for the chance to achieve near-remission and long-term improvement in function and quality of life and to alter the natural history of Crohn's disease (CD) and ulcerative colitis (UC). As a consequence of longer follow-up periods the number of side effects which may be attributed to treatment with biologics is growing significantly. Cutaneous reactions are among the most common adverse reactions. These complications include injection site reactions, cutaneous infections, immune-mediated complications such as psoriasis and lupus-like syndrome and rarely skin cancers. We review the recent literature and draw attention to dermatological side effects of anti-TNF therapy of inflammatory bowel disease.

Review article: dermatological complications of immunosuppressive and anti-TNF therapy in inflammatory bowel disease

BACKGROUND

With the expanding list of medications available to treat patients with inflammatory bowel disease (IBD), it is important to recognise adverse events, including those involving the skin. Dermatological adverse events may be confused with extra-intestinal manifestations of IBD.

AIM

To review drug-related dermatological manifestations associated with immunosuppressive and anti-tumour necrosis factor (anti-TNF) therapy.

METHODS

The literature was searched on PubMed for dermatological adverse events in IBD.

RESULTS

Present thiopurine exposure was associated with a 5.9-fold [95% confidence interval (CI), 2.1-16.4] increased risk of developing non-melanoma skin cancer (NMSC). The peak incidence is highest in Caucasians over the age of 65 years with crude incidence rates of 4.0 and 5.7/1000 patient-years for present and previous use. In anti-TNF-exposed subjects, drug-induced lupus was reported in 1% of the cases and a psoriatic rash in up to 3% of the cases. Anti-TNF monotherapy increases the risk of NMSC ~2-fold to a rate of 0.5 cases per 1000 person-years. Cutaneous lymphomas have been rarely reported in subjects on thiopurine or anti-TNF drug monotherapy. Combination therapy seems to have an additive effect on the risk of developing NMSC and lymphoma.

CONCLUSIONS

Physicians need to be aware of the wide spectrum of dermatological complications of immunosuppressive and anti-TNF therapy in IBD, especially psoriasis and non-melanoma skin cancer. Vigilance and regular screening for non-melanoma skin cancer is recommended. Case discussions between gastroenterologists and dermatologists should be undertaken to best manage dermatological adverse events.

Fueling autoimmunity: type I interferon in autoimmune diseases

In recent years, active research using genomic, cellular and animal modeling approaches has revealed the fundamental forces driving the development of autoimmune diseases. Type I interferon imprints unique molecular signatures in a list of autoimmune diseases. Interferon is induced by diverse nucleic acid-containing complexes, which trigger innate immune activation of plasmacytoid dendritic cells. Interferon primes, activates or differentiates various leukocyte populations to promote autoimmunity. Accordingly, interferon signaling is essential for the initiation and/or progression of lupus in several experimental models. However, the heterogeneous nature of systemic lupus erythematosus requires better characterization on how interferon pathways are activated and subsequently promote the advancement of autoimmune diseases. Given the central role of type I interferon, various strategies are devised to target these cytokines or related pathways to curtail the progression of autoimmune diseases.

Induction or exacerbation of psoriatic lesions during anti-TNF-α therapy for inflammatory bowel disease: a systematic literature review based on 222 cases

BACKGROUND

Paradoxical cases of psoriatic lesions induced or exacerbated by anti-tumor necrosis factor (TNF)-α therapy have been reported more frequently in recent years, but data related to inflammatory bowel disease (IBD) are rare. A systematic literature review was performed to provide information about this adverse effect in patients with IBD who receive anti-TNF therapy.

METHODS

Published studies were identified by a search of Medline, Embase, Cochrane, SciELO, and LILACS databases.

RESULTS

A total of 47 studies (222 patients) fulfilled the inclusion criteria and were selected for analysis. Clinical and therapeutic aspects varied considerably among these reports. Of the 222 patients, 78.38% were diagnosed with Crohn's disease, and 48.20% were female. The mean patient age was 26.50 years, and 70.72% of patients had no history of psoriasis. Patients developed psoriasiform lesions (55.86%) more often than other types of psoriatic lesions, and infliximab was the anti-TNF-α therapy that caused the cutaneous reaction in most patients (69.37%). Complete remission of cutaneous lesions was observed in 63.96% of the cases.

CONCLUSIONS

We found that psoriatic lesions occurred predominantly in adult patients with Crohn's disease who received infliximab and had no previous history of psoriasis. Most patients can be managed conservatively without discontinuing anti-TNF-α therapy.

Off-label uses of anti-TNF therapy in three frequent disorders: Behçet's disease, sarcoidosis, and noninfectious uveitis

Tumoral necrosis factor α plays a central role in both the inflammatory response and that of the immune system. Thus, its blockade with the so-called anti-TNF agents (infliximab, etanercept, adalimumab, certolizumab pegol, and golimumab) has turned into the most important tool in the management of a variety of disorders, such as rheumatoid arthritis, spondyloarthropatties, inflammatory bowel disease, and psoriasis. Nonetheless, theoretically, some other autoimmune disorders may benefit from these agents. Our aim is to review these off-label uses of anti-TNF blockers in three common conditions: Behçet's disease, sarcoidosis, and noninfectious uveitis. Due to the insufficient number of adequate clinical trials and consequently to their lower prevalence compared to other immune disorders, this review is mainly based on case reports and case series.

The role of inflammation and autoimmunity in the pathophysiology of pulmonary arterial hypertension

Pulmonary arterial hypertension is characterized by a remodeling of pulmonary arteries with endothelial cell, fibroblast, and vascular smooth muscle cell activation and proliferation. Since pulmonary arterial hypertension occurs frequently in autoimmune conditions such as systemic sclerosis, inflammation and autoimmunity have been suspected to play a critical role in both idiopathic pulmonary arterial hypertension and systemic sclerosis-associated pulmonary arterial hypertension. High levels of pro-inflammatory cytokines such as interleukin-1 and interleukin-6, platelet-derived growth factor, or macrophage inflammatory protein 1 have been found in lung samples of patients with pulmonary arterial hypertension, along with inflammatory cell infiltrates mainly composed of macrophages and dendritic cells, T and B lymphocytes. In addition, circulating autoantibodies are found in the peripheral blood of patients. Thus, autoimmunity and inflammation probably play a role in the development of pulmonary arterial hypertension. In this setting, it would be important to set-up new experimental models of pulmonary arterial hypertension, in order to define novel therapeutics that specifically target immune disturbances in this devastating condition.

Mechanisms of action of anti-tumor necrosis factor α agents in Crohn's disease

Crohn's disease (CD) is characterized by inflammation that can affect any part of the gastrointestinal tract. It is a chronic destructive condition that follows a relapsing-remitting course and can lead to disability and a poor quality of life. Lifelong pharmacotherapy with systemic immunomodulator therapies remains the cornerstone of CD management. Advances in understanding of the immunopathogenic mechanisms underlying chronic gut inflammation in CD have led to the development of effective biological therapies for patients with CD. Tumor necrosis factor α (TNF-α) is a potent proinflammatory cytokine that plays a pivotal role in the development of Crohn's inflammation. Therapies designed to target this cytokine have revolutionized treatment of CD since their introduction in the late 1990s, thanks to their ability to induce and maintain remission, heal mucosa, reduce hospital admissions and surgical procedures, and restore quality of life. Despite widespread use of these therapies in CD, their precise mechanism of action remains unclear, although several different mechanisms have been proposed. This review summarizes the biology of the TNF-α cytokine and the development of biological therapies targeting TNF-α, and updates our current understanding of mechanisms of action of the commercially available anti-TNF-α therapies used in the treatment of CD.

Induction and exacerbation of psoriasis with Interferon-alpha therapy for hepatitis C: a review and analysis of 36 cases

BACKGROUND

Interferon-alpha (IFN-α) therapy is used to treat hepatitis C infection. The exacerbation and occurrence of psoriasis in hepatitis C patients treated with IFN-α is increasingly recognized, but the distinct associated features, aetiology and management have not been reviewed.

OBJECTIVE

To review all published cases of hepatitis C patients who developed psoriasis while receiving IFN-α therapy.

METHODS

The review was conducted by searching the PubMed database using the keywords 'hepatitis C' AND 'psoriasis.' In addition, references to additional publications not indexed for PubMed were followed to obtain a complete record of published data.

RESULTS

We identified 32 publications describing 36 subjects who developed a psoriatic eruption while receiving IFN-α therapy for hepatitis C. Topical therapies were a commonly employed treatment modality, but led to resolution in only 30% of cases in which they were employed solely. Cessation of IFN-α therapy led to resolution in 93% of cases. Hundred per cent of those who developed psoriasis while on IFN-α therapy responded to systemic therapy and were able to continue the drug.

CONCLUSION

Further studies and analysis of IFN-α-induced lesions are necessary to clarify the role of IFN-α and the hepatitis C virus in the development of psoriatic lesions.

Biological therapy for dermatological manifestations of inflammatory bowel disease

Ulcerative colitis and Crohn’s disease are the two forms of inflammatory bowel disease (IBD). The advent of biological drugs has significantly changed the management of these conditions. Skin manifestations are not uncommon in IBD. Among the reactive lesions (immune-mediated extraintestinal manifestations), erythema nodosum (EN) and pyoderma gangrenosum (PG) are the two major cutaneous ills associated with IBD, while psoriasis is the dermatological comorbidity disease observed more often. In particular, in the last few years, anti-tumor necrosis factor (TNF)-α agents have been successfully used to treat psoriasis, especially these kinds of lesions that may occur during the treatment with biological therapies. The entity of the paradoxical manifestations has been relatively under reported as most lesions are limited and a causal relationship with the treatment is often poorly understood. The reason for this apparent side-effect of the therapy still remains unclear. Although side effects may occur, their clinical benefits are undoubted. This article reviews the therapeutic effects of the two most widely used anti-TNF-α molecules, infliximab (a fusion protein dimer of the human TNF-α receptor) and adalimumab (a fully human monoclonal antibody to TNF-α), for the treatment of the major cutaneous manifestations associated with IBD (EN, PG and psoriasis).

Infliximab-induced psoriasis and psoriasiform skin lesions in pediatric Crohn disease and a potential association with IL-23 receptor polymorphisms

BACKGROUND

Infliximab (IFX), an established therapy for pediatric Crohn disease (CD), is also efficacious in treating psoriasis, a skin disorder, in which tumor necrosis factor-α is implicated pathogenically. Paradoxically, there have been numerous reports of new-onset psoriasis following tumor necrosis factor-α antagonist therapy in adult patients with inflammatory bowel disease, but pediatric data are sparse.

METHODS

A retrospective review of all IFX-treated patients with CD, who subsequently developed psoriasis, at a single pediatric inflammatory bowel disease center, was performed. A subset of affected patients (10/18) and CD controls (147 of 172) treated with IFX but without the development of psoriasis were genotyped for polymorphisms in the interleukin-23 receptor (IL-23R) gene, which has been identified as conferring susceptibility to both CD and psoriasis.

RESULTS

Eighteen (10.5%) of 172 IFX-treated patients with CD developed new-onset psoriasis (n = 17) or worsening of existing psoriasis (n = 1). The duration of IFX exposure was variable, ranging from 1 to 25 infusions. Three patients discontinued IFX because of this complication. Most patients responded well to topical steroid therapy. In comparison to disease-matched controls, patients with CD developing psoriasis following IFX therapy were more likely to be homozygous for specific polymorphisms in the IL-23R gene (rs10489628, rs10789229, and rs1343151).

CONCLUSIONS

As in adults, the development of psoriasis or psoriasiform skin lesions occurs in pediatric patients with CD treated with IFX. Adequately powered studies are required to further explore the preliminary findings reported here to determine whether polymorphisms in the IL-23R gene have a role in the pathogenesis of this paradoxical process, which presently remains unexplained.

Biologic agents in experimental autoimmune uveitis

Experimental uveitis models were developed in an effort to elucidate the pathogenesis of human uveitis. The therapeutic effects of numerous anti-inflammatory agents including corticosteroids and immunomodulatory agents including biologic response modifiers have been investigated in both experimental and human uveitis. Monoclonal antibodies to tumor necrosis factor alpha and anti-interleukins, among others, demonstrate efficacy and are employed in the treatment of uveitis refractory to conventional immunomodulatory agents.

Breast cancer-derived transforming growth factor-β and tumor necrosis factor-α compromise interferon-α production by tumor-associated plasmacytoid dendritic cells

We previously reported that plasmacytoid dendritic cells (pDCs) infiltrating breast tumors are impaired for their interferon-α (IFN-α) production, resulting in local regulatory T cells amplification. We designed our study to decipher molecular mechanisms of such functional defect of tumor-associated pDC (TApDC) in breast cancer. We demonstrate that besides IFN-α, the production by Toll-like receptor (TLR)-activated healthy pDC of IFN-β and TNF-α but not IP-10/CXCL10 nor MIP1-α/CCL3 is impaired by the breast tumor environment. Importantly, we identified TGF-β and TNF-α as major soluble factors involved in TApDC functional alteration. Indeed, recombinant TGF-β1 and TNF-α synergistically blocked IFN-α production of TLR-activated pDC, and neutralization of TGF-β and TNF-α in tumor-derived supernatants restored pDCs' IFN-α production. The involvment of tumor-derived TGF-β was further confirmed in situ by the detection of phosphorylated Smad2 in the nuclei of TApDC in breast tumor tissues. Mechanisms of type I IFN inhibition did not involve TLR downregulation but the inhibition of IRF-7 expression and nuclear translocation in pDC after their exposure to tumor-derived supernatants or recombinant TGF-β1 and TNF-α. Our findings indicate that targeting TApDC to restore their IFN-α production might be an achievable strategy to induce antitumor immunity in breast cancer by combining TLR7/9-based immunotherapy with TGF-β and TNF-α antagonists.

The interferon signature and STAT1 expression in rheumatoid arthritis synovial fluid macrophages are induced by tumor necrosis factor α and counter-regulated by the synovial fluid microenvironment

OBJECTIVE

Type I interferons (IFNs) have emerged as potential activators of the IFN signature and elevated STAT-1 expression in rheumatoid arthritis (RA) synovium, but mechanisms that induce synovial IFN expression are unknown. Recently, tumor necrosis factor α (TNFα) was shown to induce a delayed IFN response in macrophages. We undertook this study to test whether TNFα, classically thought to activate inflammatory NF-κB target genes in RA, also contributes to the "IFN signature" in RA synovial macrophages.

METHODS

Synovial fluid (SF) macrophages purified from 24 patients with RA and 18 patients with spondylarthritides (SpA) were lysed immediately after isolation or were cultured ex vivo in the absence or presence of blockade of endogenous type I IFN or TNFα. Expression of IFN-inducible target genes was measured by quantitative reverse transcription-polymerase chain reaction, and expression of their corresponding proteins was measured by enzyme-linked immunosorbent assay.

RESULTS

Expression of an IFN signature and STAT1 in RA synovial macrophages was suppressed when type I IFNs or TNFα were blocked, whereas TNFα blockade did not affect expression of IFN response genes or STAT1 in SpA synovial macrophages. RA SF suppressed the IFN signature in RA synovial macrophages and in TNFα-, IFNα-, and IFNβ-stimulated control macrophages. Type I IFNs suppressed expression of IL8 and MMP9 in RA synovial macrophages and in TNFα-stimulated control macrophages.

CONCLUSION

Our findings identify a new function of TNFα in RA synovitis by implicating TNFα as a major inducer of the RA synovial IFN response. The results suggest that the expression of IFN response genes in RA synovium is regulated by interplay between TNFα and opposing homeostatic factors expressed in the synovial microenvironment.

Anti-tumor necrosis factor α treatment of interferon-α-induced murine lupus nephritis reduces the renal macrophage response but does not alter glomerular immune complex formation

OBJECTIVE

To analyze the mechanism for the therapeutic effects of tumor necrosis factor α (TNFα) inhibition in a murine model of systemic lupus erythematosus.

METHODS

We used the (NZB × NZW)F(1) (NZB/NZW) mouse model of interferon-α-induced lupus nephritis and treated mice with TNF receptor type II (TNFRII) Ig after TNFα expression was detected in the kidneys. Autoantibodies were measured by enzyme-linked immunosorbent assay (ELISA), and autoantibody- forming cells were determined using an enzyme-linked immunospot assay. Activation of splenocytes was analyzed by flow cytometry. Kidneys were harvested and analyzed using flow cytometry, immunohistochemistry, ELISA, Western blotting, and real-time polymerase chain reaction.

RESULTS

TNFRII Ig treatment stabilized nephritis and markedly prolonged survival. Autoantibody production and systemic immune activation were not inhibited, but the renal response to glomerular immune complex deposition was attenuated. This was associated with decreases in renal production of chemokines, renal endothelial cell activation, interstitial F4/80(high) macrophage accumulation, tubular damage, and oxidative stress. In contrast, perivascular lymphoid aggregates containing B cells, T cells, and dendritic cells accumulated unabated.

CONCLUSION

Our data suggest that TNFα is a critical cytokine that amplifies the response of the nephron to immune complex deposition, but that it has less influence on the response of the systemic vasculature to inflammation.

Onset of psoriasis in patients with inflammatory bowel disease treated with anti-TNF agents

Anti-TNF agents are widely used in the treatment of some inflammatory diseases, such as inflammatory bowel disease and psoriasis. Their use has led to a significant advance in the treatment of these diseases. Paradoxically, the onset of psoriatic lesions has been observed in patients on anti-TNF treatment. The cause of this side effect has not yet been clearly identified. In recent years, an increasing number of cases of psoriasis related to anti-TNF therapy in inflammatory bowel disease patients have been reported. Although withdrawal of anti-TNF was usually implemented in the first reports, in more recent series the maintenance of the drug with topical therapy, with the exception of the most severe or extensive forms of skin lesions, appears to be the treatment of choice. This article summarizes the relevant literature, discusses the etiopathology, epidemiology, location and phenotypes of psoriatic lesions and the management of this side effect.

Large-scale analysis of tumor necrosis factor α levels in systemic lupus erythematosus

OBJECTIVE

Systemic lupus erythematosus (SLE) disease manifestations are highly variable among patients, and the prevalence of individual clinical features differs significantly by ancestry. Serum tumor necrosis factor α (TNFα) levels are elevated in some SLE patients and may play a role in disease pathogenesis. The aim of this study was to look for associations between serum TNFα levels, clinical manifestations of SLE, autoantibodies, and serum interferon-α (IFNα) levels in a large multiancestral SLE cohort.

METHODS

We studied serum TNFα levels in 653 SLE patients (214 African Americans, 298 European Americans, and 141 Hispanic Americans). TNFα was measured using an enzyme-linked immunosorbent assay, and IFNα was measured with a functional reporter cell assay. Stratified and multivariate analyses were used to detect associations in each ancestral background separately, with meta-analysis when appropriate.

RESULTS

Serum TNFα levels were significantly higher in SLE patients than in non-autoimmune disease controls (P < 5.0 × 10(-3) for each ancestral background). High serum TNFα levels were positively correlated with high serum IFNα levels when tested in the same sample across all ancestral backgrounds (odds ratio range 1.76-1.86, P = 4.8 × 10(-3) by Fisher's combined probability test). While serum TNFα levels alone did not differ significantly among SLE patients of different ancestral backgrounds, the proportion of patients with concurrently high levels of TNFα and IFNα was highest in African Americans and lowest in European Americans (P = 5.0 × 10(-3) ). Serum TNFα levels were not associated with autoantibodies, clinical criteria for the diagnosis of SLE, or age at the time of sampling.

CONCLUSION

Serum TNFα levels are high in many SLE patients, and we observed a positive correlation between serum TNFα and IFNα levels. These data support a role for TNFα in the pathogenesis of SLE across all ancestral backgrounds and suggest important cytokine subgroups within the disease.

Circulating dendritic cell number and intracellular TNF-α production in women with type 2 diabetes

Human dendritic cell (DC) subsets perform specialized functions for surveillance against bacterial and viral infections essential for the management of type 2 diabetes (T2D). Production of tumor necrosis factor-alpha (TNF-α) by DCs acts in autocrine fashion to regulate DC maturation and promotes the inflammatory response. This study was designed to compare circulating DC number and intracellular TNF-α production between post-menopausal women with T2D and healthy women. Blood samples were obtained (n = 21/group) and examined for plasma glucose and TNF-α concentrations, and dendritic cell subset immunophenotype (plasmacytoid, pDC, CD85k(ILT-3)(+)CD123(+)CD16(-)CD14(-) and myeloid, mDC, CD85k(ILT-3)(+)CD33(+)CD123(dim to neg)CD16(-)CD14(dim to neg)). Intracellular production of TNF-α was determined in unstimulated and stimulated DCs. Women with T2D had significantly (P < 0.05) greater plasma glucose and TNF-α concentrations when compared to healthy women. Women with T2D having poor glycemic control (T2D Poor Control, HbA1c ≥ 7%) had fewer circulating pDCs than women with T2D having good glycemic control (T2D Good Control, HbA1c < 7%) and healthy women. A significant interaction (P = 0.011) was observed between the effects of plasma glucose and group for intracellular expression of TNF-α in stimulated pDCs. Intracellular production of TNF-α in pDCs was significantly greater in healthy vs. T2D Poor Control (P < 0.0001) and T2D Good Control (P < 0.0001) but did not differ between T2D subgroups. The mDC number and intracellular production of TNF-α did not differ between groups. These findings indicate that TNF-α production by pDCs was reduced in women with T2D and circulating number of pDCs was associated with glycemic control.

Cytokine inhibition as a strategy for treating systemic lupus erythematosus

Cytokines regulate and control the immune system. In systemic lupus erythematosus, several of these cytokines are overexpressed and contribute to the pathogenesis of the disease. Cytokine inhibition has been successfully used to treat other rheumatic and autoimmune diseases, and several cytokines are currently being investigated to determine whether inhibition would be therapeutic in lupus. The cytokines discussed in this review have all undergone clinical trials, and include TNF-α, IL-1, IL-6, IL-10, IL-15, IL-17, IL-18 and IL-23. Inhibition of the majority of these targets was safe and showed some efficacy in treating lupus. Cytokine inhibition strategies have just started to realize their potential for the treatment of this difficult disease, and show great promise for the future.

EBV stimulates TLR- and autophagy-dependent pathways and impairs maturation in plasmacytoid dendritic cells: implications for viral immune escape

Plasmacytoid DCs (pDCs) are crucial mediators in the establishment of immunity against most viruses, given their extraordinary capacity to produce a massive quantity of type I IFN. In this study we investigate the response of pDCs to infection with EBV, a γ-herpes virus that persists with an asymptomatic infection in immunocompetent hosts, although in certain conditions it can promote development of cancers or autoimmune diseases. We show that high amounts of type I IFNs were released from isolated pDCs after exposure to EBV by a mechanism requiring TLRs and a functional autophagic machinery. We next demonstrate that EBV can infect pDCs via viral binding to MHC class II molecule HLA-DR and that pDCs express EBV-induced latency genes. Furthermore, we observe that EBV is able to induce activation but not maturation of pDCs, which correlates with an impaired TNF-α release. Accordingly, EBV-infected pDCs are unable to mount a full T-cell response, suggesting that impaired pDC maturation, combined with a concomitant EBV-mediated upregulation of the T-cell inhibitory molecules B7-H1 and ICOS-L, could represent an immune-evasion strategy promoted by the virus. These mechanisms might lead to persistence in immunocompetent hosts or to dysregulated immune responses linked to EBV-associated diseases.

Anti-TNF-alpha induced psoriasiform eruptions with severe scalp involvement and alopecia: report of five cases and review of the literature

We describe 5 cases of anti-tumor necrosis factor-alpha (anti-TNF-α) induced psoriasiform eruptions with severe scalp involvement inducing inflammatory alopecia and review the literature on this subject. All our 5 patients were provided topical therapy, with good results in only 1 case. The remaining 4 were provided systemic therapy (methotrexate ± cyclosporine): 3 concomitantly suspended the anti-TNF-α treatment (2 are currently clear/almost clear but 1 has so far only observed mild improvement) and 1 switched anti-TNF-α (recurrent flare-ups of the disease continue). So far, no patient has developed scarring alopecia. To our knowledge, a total of 15 cases of anti-TNF-α induced psoriatic alopecia have been described. Anti-TNF-α was discontinued in 9 of the 15 patients and systemic therapy was provided to 9 of the 15 patients. Nonetheless, 2 patients developed scarring alopecia. We conclude that in anti-TNF-α induced psoriasiform eruptions some patients may respond to topical treatment, however in cases of severe scalp involvement anti-TNF-α suspension and systemic treatment should be considered in order to avoid scarring alopecia.

Thromboembolic events and anti-tumor necrosis factor therapies

Thromboembolic (TE) events have been observed in about 4.5% of patients treated with TNF antagonists. It has been suggested that anti-drug antibodies could be involved. However, another mechanism fits more with the available immunochemical data and could lead to practical measures to prevent TE events during anti-TNF therapies. Adverse effects are not related to the type of antagonist, but well to the combination of the inhibition of TNF and the predisposition of some patients to lupus-like reactions, including antiphospholipid syndrome. The overproduction of interferon-α, caused by the inhibition of TNF in these individuals would foster the development of lupus-like syndrome. Therefore, seeking conventional markers of systemic lupus erythematosus (e.g. anti-dsDNA, anti-phospholipid, anti-β(2)-glycoprotein antibodies) before the administration of an anti-TNF could be a prudent measure.

Paradoxical inflammation induced by anti-TNF agents in patients with IBD

Anti-TNF antibodies have acquired a prominent place in the management of IBD (including Crohn's disease and ulcerative colitis), rheumatologic conditions (such as rheumatoid arthritis, ankylosing spondylitis and psoriatic arthritis) and psoriasis. They have a good safety profile, especially when contraindications such as demyelinating disease, active infections and/or abscesses are ruled out, and when necessary precautions to prevent reactivation of tuberculosis are taken. However, with increasing use of these agents, paradoxical adverse events have been reported. Some of these features are shared with the underlying disease for which these drugs are given, making management of these conditions challenging. For example, anti-TNF therapy is used for the treatment of psoriasis, but psoriasiform lesions are sometimes observed in patients receiving therapy. Similarly, anti-TNF therapy is used for the treatment of rheumatologic diseases, but arthralgias and arthritis are sometimes observed in patients receiving anti-TNF agents. We review the paradoxical inflammation induced by anti-TNF agents in patients with IBD, provide hypotheses for the occurrence of this paradoxical inflammation and give practical advice on how to manage these patients.

Irf5-deficient mice are protected from pristane-induced lupus via increased Th2 cytokines and altered IgG class switching

Polymorphisms in the transcription factor interferon (IFN) regulatory factor 5 (IRF5) have been identified that show a strong association with an increased risk of developing the autoimmune disease systemic lupus erythematosus (SLE). A potential pathological role for IRF5 in SLE development is supported by the fact that increased IRF5 mRNA and protein are observed in primary blood cells of SLE patients and this correlates with an increased risk of developing the disease. Here, we demonstrate that IRF5 is required for pristane-induced SLE via its ability to control multiple facets of autoimmunity. We show that IRF5 is required for pathological hypergammaglobulinemia and, in the absence of IRF5, IgG class switching is reduced. Examination of in vivo cytokine expression (and autoantibody production) identified an increase in Irf5(-/-) mice of Th2 cytokines. In addition, we provide clear evidence that loss of Irf5 significantly weakens the in vivo type I IFN signature critical for disease pathogenesis in this model of murine lupus. Together, these findings demonstrate the importance of IRF5 for autoimmunity and provide a significant new insight into how overexpression of IRF5 in blood cells of SLE patients may contribute to disease pathogenesis.

Detection of gene expression signatures related to underlying disease and treatment in rheumatoid arthritis patients

OBJECTIVES

Gene expression signatures can provide an unbiased view into the molecular changes underlying biologically and medically interesting phenotypes. We therefore initiated this study to identify signatures that would be of utility in studying rheumatoid arthritis (RA).

METHODS

We used microarray profiling of peripheral blood mononuclear cells (PBMCs) in 30 RA patients to assess the effect of different biologic agent (biologics) treatments and to quantify the degree of a type-I interferon (IFN) signature in these patients. A numeric score was derived for the quantification step and applied to patients with RA. To further characterize the IFN response in our cohort, we employed type-I IFN treatment of PBMCs in vitro and in reporter assays.

RESULTS

Profiling identified a subset of RA patients with upregulation of type-I IFN-regulated transcripts, thereby corroborating previous reports showing RA to be heterogeneous for an IFN component. A comparison of individuals currently untreated with a biologic with those treated with infliximab, tocilizumab, or abatacept suggested that each biologic induces a specific gene signature in PBMCs.

CONCLUSIONS

It is possible to observe signs of type-I IFN pathway activation in a subset of clinically active RA patients without C-reactive protein elevation. Furthermore, biologics-specific gene signatures in patients with RA indicate that looking for a biologic-specific response pattern may be a potential future tool for predicting individual patient response.

Endothelial cells and fibroblasts amplify the arthritogenic type I IFN response in murine Lyme disease and are major sources of chemokines in Borrelia burgdorferi-infected joint tissue

Localized elevation in type I IFN has been uniquely linked to the severe Lyme arthritis that develops in C3H mice infected with the spirochete Borrelia burgdorferi. In this study, the dynamic interactions that result in generation of these responses were further examined in C3H mice carrying the type I IFN receptor gene ablation, which effectively blocks all autocrine/paracrine signaling crucial to induction of downstream effectors. Reciprocal radiation chimeras between C3H and IFNAR1⁻/⁻ mice implicated both radiation-sensitive and radiation-resistant cells of the joint tissue in the proarthritic induction of type I IFN. Ex vivo analysis of cells from the naive joint revealed CD45⁺ cells residing in the tissue to be uniquely capable of initiating the type I IFN response to B. burgdorferi. Type I IFN responses were analyzed in real time by lineage sorting of cells from infected joint tissue. This demonstrated that myeloid cells, endothelial cells, and fibroblasts were responsible for propagating the robust IFN response, which peaked at day 7 postinfection and rapidly resolved. Endothelial cells and fibroblasts were the dominant sources of IFN signature transcripts in the joint tissue. Fibroblasts were also the major early source of chemokines associated with polymorphonuclear leukocyte and monocyte/macrophage infiltration, thus providing a focal point for arthritis development. These findings suggest joint-localized interactions among related and unrelated stromal, endothelial, and myeloid cell lineages that may be broadly applicable to understanding the pathogeneses of diseases associated with type I IFN signature, including systemic lupus erythematosus and some rheumatoid arthritides.

Role of transcriptional coregulator GRIP1 in the anti-inflammatory actions of glucocorticoids

Inhibition of cytokine gene expression by the hormone-activated glucocorticoid receptor (GR) is the key component of the anti-inflammatory actions of glucocorticoids, yet the underlying molecular mechanisms remain obscure. Here we report that glucocorticoid repression of cytokine genes in primary macrophages is mediated by GR-interacting protein (GRIP)1, a transcriptional coregulator of the p160 family, which is recruited to the p65-occupied genomic NFκB-binding sites in conjunction with liganded GR. We created a mouse strain enabling a conditional hematopoietic cell-restricted deletion of GRIP1 in adult animals. In this model, GRIP1 depletion in macrophages attenuated in a dose-dependent manner repression of NFκB target genes by GR irrespective of the upstream Toll-like receptor pathway responsible for their activation. Furthermore, genome-wide transcriptome analysis revealed a broad derepression of lipopolysaccharide (LPS)-induced glucocorticoid-sensitive targets in GRIP1-depleted macrophages without affecting their activation by LPS. Consistently, conditional GRIP1-deficient mice were sensitized, relative to the wild type, to a systemic inflammatory challenge developing characteristic signs of LPS-induced shock. Thus, by serving as a GR corepressor, GRIP1 facilitates the anti-inflammatory effects of glucocorticoids in vivo.

Induction of psoriasis with anti-TNF agents in patients with inflammatory bowel disease: a report of 21 cases

AIM

Anti-tumor necrosis factor (TNF)-alpha agents are widely used for the treatment of both inflammatory bowel disease (IBD) and psoriasis. Psoriatic skin lesions induced by anti-TNF have been described in patients with IBD. We report a case series of psoriasis induced by anti-TNF agents in IBD patients.

METHODS

Systematic analysis of cases of psoriasis induced by anti-TNF in an IBD patient cohort in tertiary hospitals of Madrid.

RESULTS

A total of 21 of 1294 patients with IBD treated with anti-TNF-alpha agents developed drug-induced psoriasis (cumulative incidence 1.62%; 95% CI 1.06%-2.47%): 14 patients with infliximab and 7 with adalimumab; seventeen with Crohn's disease, 4 with ulcerative colitis. The onset of skin lesions varied in a wide range of time (after a mean 13±8 doses). The most frequent site of skin lesions was the limbs (62%) followed by the trunk (48%) and the scalp (43%). The psoriasis phenotypes were plaque psoriasis (57%), scalp (14%), palmoplantar pustulosis (14%), pustular generalized psoriasis (5%), guttate (5%) and inverse (5%). Four patients interrupted the anti-TNF treatment, and that led to the complete regression of lesions in 1 of them. The other 17 patients were maintained on anti-TNF therapy and managed with topical steroids.

CONCLUSION

Psoriatic lesions can be induced by anti-TNF drugs. Plaque psoriasis on the extremities and trunk were the most frequent presentations in our series. Topical steroid treatment is effective in most patients. Anti-TNF discontinuance may be reserved for patients with severe psoriasis or patients without response to topical therapy.

Myeloid dendritic cells from B6.NZM Sle1/Sle2/Sle3 lupus-prone mice express an IFN signature that precedes disease onset

Patients with systemic lupus erythematosus show an overexpression of type I IFN-responsive genes that is referred to as "IFN signature." We found that B6.NZMSle1/Sle2/Sle3 (Sle1,2,3) lupus-prone mice also express an IFN signature compared with non-autoimmune C57BL/6 mice. In vitro, myeloid dendritic cells (mDCs) (GM-CSF bone marrow-derived dendritic cells; BMDCs) from Sle1,2,3 mice constitutively overexpressed IFN-responsive genes such as IFN-β, Oas-3, Mx-1, ISG-15, and CXCL10 and members of the IFN signaling pathway STAT1, STAT2, and IRF7. The IFN signature was similar in Sle1,2,3 BMDCs from young, pre-autoimmune mice and from mice with high titers of autoantibodies, suggesting that the IFN signature in mDCs precedes disease onset and is independent from the autoantibodies. Sle1,2,3 BMDCs hyperresponded to stimulation with IFN-α and the TLR7 and TLR9 agonists R848 and CpGs. We propose that this hyperresponse is induced by the IFN signature and only partially contributes to the signature, as oligonucleotides inhibitory for TLR7 and TLR9 only partially suppressed the constitutive IFN signature, and pre-exposure to IFN-α induced the same hyperresponse in wild-type BMDCs as in Sle1,2,3 BMDCs. In vivo, mDCs and to a lesser extent T and B cells from young prediseased Sle1,2,3 mice also expressed the IFN signature, although they lacked the strength that BMDCs showed in vitro. Sle1,2,3 plasmacytoid DCs expressed the IFN signature in vitro but not in vivo, suggesting that mDCs may be more relevant before disease onset. We propose that Sle1,2,3 mice are useful tools to study the role of the IFN signature in lupus pathogenesis.

The multifaceted balance of TNF-α and type I/II interferon responses in SLE and RA: how monocytes manage the impact of cytokines

Many cytokines are involved in the pathogenesis of autoimmune diseases and are recognized as relevant therapeutic targets to attenuate inflammation, such as tumor necrosis factor (TNF)-α in rheumatoid arthritis (RA) and interferon (IFN)-α/γ in systemic lupus erythematosus (SLE). To relate the transcriptional imprinting of cytokines in a cell type- and disease-specific manner, we generated gene expression profiles from peripheral monocytes of SLE and RA patients and compared them to in vitro-generated signatures induced by TNF-α, IFN-α2a, and IFN-γ. Monocytes from SLE and RA patients revealed disease-specific gene expression profiles. In vitro-generated signatures induced by IFN-α2a and IFN-γ showed similar profiles that only partially overlapped with those induced by TNF-α. Comparisons between disease-specific and in vitro-generated signatures identified cytokine-regulated genes in SLE and RA with qualitative and quantitative differences. The IFN responses in SLE and RA were found to be regulated in a STAT1-dependent and STAT1-independent manner, respectively. Similarly, genes recognized as TNF-α regulated were clearly distinguishable between RA and SLE patients. While the activity of SLE monocytes was mainly driven by IFN, the activity from RA monocytes showed a dominance of TNF-α that was characterized by STAT1 down-regulation. The responses to specific cytokines were revealed to be disease-dependent and reflected the interplay of cytokines within various inflammatory milieus. This study has demonstrated that monocytes from RA and SLE patients exhibit disease-specific gene expression profiles, which can be molecularly dissected when compared with in vitro-generated cytokine signatures. The results suggest that an assessment of cytokine-response status in monocytes may be helpful for improvement of diagnosis and selection of the best cytokine target for therapeutic intervention.

Neutralization of tumor necrosis factor bioactivity ameliorates urethane-induced pulmonary oncogenesis in mice

Tumor necrosis factor (TNF) has been implicated in inflammation-associated tumor progression. Although multiple reports identified a role for TNF signaling in established cancers, few studies have assessed the impact of TNF blockade on early tumor formation promotion. We aimed at exploring the effects of TNF neutralization in a preclinical mouse model of lung carcinogenesis. For this, Balb/c mice (n = 42) received four weekly intraperitoneal urethane injections (1 g/kg) and twice-weekly intraperitoneal soluble TNF receptor (etanercept; 10 mg/kg) administered during tumor initiation/promotion, tumor progression, or continuously (months 1, 6, and 1-8 after urethane start, respectively). Lung oncogenesis was assessed after 8 months. In separate short-term studies, Balb/c mice (n = 21) received a single control or urethane injection followed by twice-weekly intraperitoneal control or sTNFR:Fc injections. Lung inflammation was assessed after 1 week. We found that sTNFR:Fc treatment during tumor initiation/promotion resulted in a significant reduction of tumor number but not dimensions. However, sTNFR:Fc administered during tumor progression did not impact tumor multiplicity but significantly decreased tumor diameter. Continued sTNFR:Fc administration was effective in halting both respiratory tumor formation and progression in response to urethane. This favorable impact was associated with impaired cellular proliferation and new vessel formation in lung tumors. In addition, TNF neutralization altered the lung inflammatory response to urethane, evidenced by reductions in TNF and macrophage and increases in interferon γ and interleukin 10 content of the air spaces. sTNFR:Fc treatment of RAW264.7 macrophages downregulated TNF and enhanced interferon γ and interleukin 10 expression. In conclusion, TNF neutralization is effective against urethane-induced lung oncogenesis in mice and could present a lung chemoprevention strategy worth testing clinically.

TLR tolerance reduces IFN-alpha production despite plasmacytoid dendritic cell expansion and anti-nuclear antibodies in NZB bicongenic mice

Genetic loci on New Zealand Black (NZB) chromosomes 1 and 13 play a significant role in the development of lupus-like autoimmune disease. We have previously shown that C57BL/6 (B6) congenic mice with homozygous NZB chromosome 1 (B6.NZBc1) or 13 (B6.NZBc13) intervals develop anti-nuclear antibodies and mild glomerulonephritis (GN), together with increased T and B cell activation. Here, we produced B6.NZBc1c13 bicongenic mice with both intervals, and demonstrate several novel phenotypes including: marked plasmacytoid and myeloid dendritic cell expansion, and elevated IgA production. Despite these changes, only minor increases in anti-nuclear antibody production were seen, and the severity of GN was reduced as compared to B6.NZBc1 mice. Although bicongenic mice had increased levels of baff and tnf-α mRNA in their spleens, the levels of IFN-α-induced gene expression were reduced. Splenocytes from bicongenic mice also demonstrated reduced secretion of IFN-α following TLR stimulation in vitro. This reduction was not due to inhibition by TNF-α and IL-10, or regulation by other cellular populations. Because pDC in bicongenic mice are chronically exposed to nuclear antigen-containing immune complexes in vivo, we examined whether repeated stimulation of mouse pDC with TLR ligands leads to impaired IFN-α production, a phenomenon termed TLR tolerance. Bone marrow pDC from both B6 and bicongenic mice demonstrated markedly inhibited secretion of IFN-α following repeated stimulation with a TLR9 ligand. Our findings suggest that the expansion of pDC and production of anti-nuclear antibodies need not be associated with increased IFN-α production and severe kidney disease, revealing additional complexity in the regulation of autoimmunity in systemic lupus erythematosus.

Methotrexate for psoriasiform lesions associated with anti-tumour necrosis factor therapy in inflammatory bowel disease

BACKGROUND

Psoriasiform lesions associated with anti-tumour necrosis factor (TNF) therapy are frequent in patients with inflammatory bowel disease (IBD). While methotrexate is the most frequently used systemic treatment for psoriasis, its efficacy for psoriasiform lesions related to anti-TNF therapy remains unknown.

AIMS

To assess the efficacy of methotrexate for psoriasiform lesions associated with anti-TNF therapy refractory to topical therapy in IBD patients.

METHODS

The charts of eight patients from the Nancy IBD cohort who developed psoriasiform lesions on anti-TNF therapy were reviewed. Clinical response was defined as a decrease of more than 50% in the lesions covering surface. All patients were followed up by the same experienced dermatologist.

RESULTS

Eight women (seven Crohn's disease) were followed up for a median duration of 29 months (range, 20-45). Of the eight patients receiving methotrexate, three were primary responders without discontinuation of anti-TNF agents. Only one patient had a sustained response at final follow-up and was able to continue both methotrexate and anti-TNF therapy. Of the two other primary responders, one patient had to discontinue anti-TNF because of severe psoriasiform lesions, whereas the other one continued anti-TNF therapy despite persistent skin lesions at final follow-up. Among the five primary nonresponders, four patients had to stop anti-TNF treatment due to disabling skin lesions.

CONCLUSION

Methotrexate does not appear effective in treating psoriasiform lesions associated with anti-TNF therapy refractory to topical therapy in IBD.

TNF-α and TGF-β counter-regulate PD-L1 expression on monocytes in systemic lupus erythematosus

Monocytes in patients with systemic lupus erythematosus (SLE) are hyperstimulatory for T lymphocytes. We previously found that the normal program for expression of a negative costimulatory molecule programmed death ligand-1 (PD-L1) is defective in SLE patients with active disease. Here, we investigated the mechanism for PD-L1 dysregulation on lupus monocytes. We found that PD-L1 expression on cultured SLE monocytes correlated with TNF-α expression. Exogenous TNF-α restored PD-L1 expression on lupus monocytes. Conversely, TGF-β inversely correlated with PD-L1 in SLE and suppressed expression of PD-L1 on healthy monocytes. Therefore, PD-L1 expression in monocytes is regulated by opposing actions of TNF-α and TGF-β. As PD-L1 functions to fine tune lymphocyte activation, dysregulation of cytokines resulting in reduced expression could lead to loss of peripheral T cell tolerance.

Roles of pro- and anti-inflammatory cytokines in the pathogenesis of SLE

SLE is an autoimmune inflammatory disease in which various pro- and anti-inflammatory cytokines, including TGF-β, IL-10, BAFF, IL-6, IFN-α, IFN-γ, IL-17, and IL-23, play crucial pathogenic roles. Virtually, all these cytokines can be generated by both innate and adaptive immune cells and exert different effects depending on specific local microenvironment. They can also interact with each other, forming a complex network to maintain delicate immune homeostasis. In this paper, we elaborate on the abnormal secretion and functions of these cytokines in SLE, analyze their potential pathogenic roles, and probe into the possibility of them being utilized as targets for therapy.