The biology of TNF blockade

Drug-Induced Enterocolitis Syndrome in Children

Drug-Induced Enterocolitis Syndrome (DIES) is a drug-induced hypersensitivity reaction non-IgE mediated involving the gastrointestinal system that occurs 2 to 4 h after drug administration. Antibiotics, specifically amoxicillin or amoxicillin/clavulanate, represent the most frequent drugs involved. Symptoms include nausea, vomiting, abdominal pain, diarrhea, pallor, lethargy, and dehydration, which can be severe and result in hypovolemic shock. The main laboratory finding is neutrophilic leukocytosis. To the best of our knowledge, 12 cases of DIES (9 children-onset and 3 adult-onset cases) were described in the literature. DIES is a rare clinically well-described allergic disease; however, the pathogenetic mechanism is still unclear. It requires to be recognized early and correctly treated by physicians.

Positive antiphospholipid antibodies and pulmonary embolism in a patient with adalimumab-induced lupus

It is known that administration of tumor necrotic factor (TNF) inhibitors induces lupus. The case of a Crohn's disease patient who had been treated with adalimumab (ADA) and showed positive anti-DNA and antiphospholipid antibodies and developed pulmonary embolism is presented. Fortunately, early diagnosis and intervention helped her survive. Although ADA was withdrawn, the Crohn's disease did not recur, and the autoantibodies became negative without any steroid therapy. It is important to recognise that administration of TNF inhibitors may be associated with antiphospholipid syndrome. It is necessary to perform therapeutic interventions such as TNF inhibitor withdrawal and prompt anticoagulant therapy when such pathology is suspected.

Current and emerging biologics for the treatment of juvenile idiopathic arthritis

INTRODUCTION

The management of a child with juvenile idiopathic arthritis (JIA) requires a combination of pharmacological, physical, and psychosocial therapies in order to induce disease remission, by controlling articular and systemic inflammation. This review aims to provide a comprehensive discussion on the biological therapies currently in use in the treatment of JIA referring to existing recommendations and clinical evidence. We also discuss on the emerging biological drugs actually under consideration.

AREAS COVERED

Recent findings on immunological mechanisms involved in the pathogenesis of the disease allowed us to identify several specific targets for biologic therapies. A systematic literature review was conducted between January 1997 and January 2020 on PubMed including national and international guidelines and recommendations, trials and case-control studies.

EXPERT OPINION

There is now a plethora of therapies that are directed against variable targets, and the physician has to choose the most appropriate available medication in order to achieve early and sustained remission with as few side effects as possible. Research is advancing very fast in order to be more and more specific in suppressing inflammatory pathways without harming natural defenses. Finally, pharmacoeconomic considerations will also be very important to deal with, considering the high cost of most of these molecules.

The T-SPOT.TB assay used for screening and monitoring of latent tuberculosis infection in patients with Behçet's disease pre- and post-anti-TNF treatment: A retrospective study

BACKGROUND

Patients undergoing anti-tumor necrosis factor (TNF) treatment are more susceptible to latent tuberculosis infection (LTBI). The aim of the current study was to determine the rate of active tuberculosis (TB) in patients with Behçet's disease (BD) pre- and post-anti-TNF treatment and to evaluate the long-term efficacy of LTBI screening as primary prophylaxis in China.

METHODS

This retrospective study included BD patients eligible for anti-TNF therapy at a single institution in Fudan University, China. On the basis of the results of T-SPOT.TB assay, chest radiograph, and history of exposure to TB, patients were screened and regularly followed up at 3-months interval.

RESULTS

Eighty-nine BD patients with mean disease duration of 87.5 ± 86.1 months were included. Their median duration of anti-TNF therapy was 10.6 months; 51 patients were treated with Infliximab, 38 with Etanercept, and four with Adalimumab. While 84 patients received a consecutive single anti-TNF drug therapy, five patients switched to a second drug. Twelve patients demonstrated positive results in LTBI screening: three had history of TB exposure and nine were solely T-SPOT.TB-positive patients. Before anti-TNF treatment, LTBI treatment was initiated in 11 patients, and one patient refused treatment. With a median follow-up period of 27.9 months, we observed only one case (1.1%) of intestinal TB during Infliximab treatment.

CONCLUSION

Regardless of anti-TNF treatment, long-term screening via T-SPOT.TB assay might represent a more sensitive approach to identify BD patients with LTBI. As a secondary prophylaxis, the LTBI treatment is effective in a country with high risk of TB.

Cytosolic group IVA phospholipase A2 inhibitors, AVX001 and AVX002, ameliorate collagen-induced arthritis

Background

Cytosolic phospholipase A2 group IVA (cPLA2α)-deficient mice are resistant to collagen-induced arthritis, suggesting that cPLA2α is an important therapeutic target. Here, the anti-inflammatory effects of the AVX001 and AVX002 cPLA2α inhibitors were investigated.

Methods

In vitro enzyme activity was assessed by a modified Dole assay. Effects on inhibiting IL-1β-induced release of arachidonic acid (AA) and prostaglandin E2 (PGE2) were measured using SW982 synoviocyte cells. In vivo effects were studied in prophylactic and therapetic murine collagen-induced arthritis models and compared to methotrexate (MTX) and Enbrel, commonly used anti-rheumatic drugs. The in vivo response to treatment was evaluated in terms of the arthritis index (AI), histopathology scores and by plasma levels of PGE2 following 14 and 21 days of treatment.

Results

Both cPLA2α inhibitors are potent inhibitors of cPLA2α in vitro. In synoviocytes, AVX001 and AVX002 reduce, but do not block, release of AA or PGE2 synthesis. In both CIA models, the AI and progression of arthritis were significantly lower in the mice treated with AVX001, AVX002, Enbrel and MTX than in non- treated mice. Several histopathology parameters of joint damage were found to be significantly reduced by AVX001 and AVX002 in both prophylactic and therapeutic study modes; namely articular cavity and peripheral tissue inflammatory cell infiltration; capillary and synovial hyperplasia; articular cartilage surface damage; and periostal and endochondral ossification. In comparison, MTX did not significantly improve any histopathology parameters and Enbrel only improved ossification. Finally, as a biomarker of inflammation and as an indication that AVX001 and AVX002 blocked the cPLA2α target, we determined that plasma levels of PGE2 were significantly reduced in response to the AVX inhibitors and MTX, but not Enbrel.

Conclusions

AVX001 and AVX002 display potent anti-inflammatory activity and disease-modifying properties in cellular and in vivo models. The in vivo effects of AVX001 and AVX002 were comparable to, or superior, to those of MTX and Enbrel. Taken together, this study suggests that cPLA2α inhibitors AVX001 and AVX002 are promising small molecule disease-modifying anti-rheumatic therapies.

Efficacy of Bioactive Cyclic Peptides in Rheumatoid Arthritis: Translation from In Vitro to In Vivo Models

Using a novel drug discovery technology reported in previous issues of this journal cyclic peptides have been created which are able to down-regulate secretion of inflammatory cytokines, in vitro, by stimulated cells of the macrophage cell line J774. The cytokines in question, TNF-alpha and IL-6, are strongly implicated in etiology of diseases such as rheumatoid arthritis. Studies are reported here using the CAIA animal model for rheumatoid arthritis, which show that the peptides identified are indeed able to impact on inflammation of joints, induced in vivo. The results suggest that these peptides are effective at a dose which could be viable in man, and at which no adverse side effects are evident in the short term.

Elderly psoriatic arthritis patients on TNF-α blockers: results of an Italian multicenter study on minimal disease activity and drug discontinuation rate

Psoriatic arthritis (PsA) is an inflammatory arthropathy, associated with skin and/or nail psoriasis. Real world data on efficacy and safety of TNF-α blockers in the elderly with PsA are lacking. The aim of this study was to evaluate the effectiveness, through the achievement of minimal disease activity (MDA), drug discontinuation rate, and safety in elderly patients with PsA on TNF-α blockers. A multicenter, observational study was carried out in four Italian centers. The assessment of disease activity and safety were performed at the start of anti-TNF-α (T0), at 6 months (T6) and at 12 months (T12). A total of 145 PsA patients were included in the study. At baseline 68 (46.9%) patients were on etanercept, 60 (41.3%) on adalimumab, 11 (7.6%) on golimumab, and 6 (4.1%) on infliximab. All the variables concerning PsA activity showed a statistically significant improvement when comparing T6 and T12 with T0. After 6 and 12 months of therapy, respectively, 31 (22.6%) and 71 (51.8%) patients achieved MDA (p < 0.001). The drug discontinuation rate was 5.5% with a mean of 6.8 months (range 2-10 months), and it was due to lack of efficacy, adverse events, and lost to follow-up. Nine patients (6.2%) reported the onset of mild infections resolved with antimicrobial specific oral regimen without therapy interruption. TNF-α blockers are effective in the achievement of a low disease status and safe in elderly patients with PsA. Therefore, age should not be considered a limitation to their use.

TNF-alpha inhibitor associated myelopathies: A neurological complication in patients with rheumatologic disorders

OBJECTIVES

Tumor necrosis factor-alpha inhibitors (TNFα-I) are biological agents used in the treatment of rheumatologic disorders. TNFα-I have been associated with demyelinating disorders mimicking multiple sclerosis. The goal of this report is to illustrate cases of myelopathy which developed during the use of TNFα-I.

METHODS

We describe the clinical, neuroimaging and laboratory features of 4 cases of myelopathy associated with TNFα-I.

RESULTS

The mean period of TNFα-I exposure was 27 [12-36] months. Three of the four patients exhibited active inflammatory myelopathy as the spinal cord MRI lesions enhanced with gadolinium and CSF pleocytosis or oligoclonal bands were present. All patients had normal brain MRIs at the time of presentation.

CONCLUSIONS

TNFα-I may play a role in the development of myelopathies in absence of brain involvement or other features of demyelinating disease. TNFα-I associated myelopathy should be considered in patients with history of treatment with TNFα-I who exhibit symptoms of myelopathy.

TLRs, future potential therapeutic targets for RA

Toll like receptors (TLR)s have a central role in regulating innate immunity and in the last decade studies have begun to reveal their significance in potentiating autoimmune diseases such as rheumatoid arthritis (RA). Earlier investigations have highlighted the importance of TLR2 and TLR4 function in RA pathogenesis. In this review, we discuss the newer data that indicate roles for TLR5 and TLR7 in RA and its preclinical models. We evaluate the pathogenicity of TLRs in RA myeloid cells, synovial tissue fibroblasts, T cells, osteoclast progenitor cells and endothelial cells. These observations establish that ligation of TLRs can transform RA myeloid cells into M1 macrophages and that the inflammatory factors secreted from M1 and RA synovial tissue fibroblasts participate in TH-17 cell development. From the investigations conducted in RA preclinical models, we conclude that TLR-mediated inflammation can result in osteoclastic bone erosion by interconnecting the myeloid and TH-17 cell response to joint vascularization. In light of emerging unique aspects of TLR function, we summarize the novel approaches that are being tested to impair TLR activation in RA patients.

Incidence of Malignancies in a Cohort of Psoriatic Arthritis Patients Taking Traditional Disease Modifying Antirheumatic Drug and Tumor Necrosis Factor Inhibitor Therapy: An Observational Study

Objective.

Psoriatic arthritis (PsA) is an inflammatory arthropathy, associated with skin and/or nail psoriasis. As suggested in 2012 by the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA), studies devoted to assess cancer in the PsA population are still limited and need to be increased. Therefore, the aim of this study was to determine the incidence of malignancies in patients with PsA who are taking conventional and biologic therapies.

Methods.

A cohort of patients with PsA was followed prospectively. At first visit, as well as at each 3–4 month followup visit, according to standardized clinical practice, medical history, and physical and laboratory findings were recorded. Information on the presence of comorbidities, as well as malignancies, was collected. At each visit, data were recorded on radiography and pathology, confirming malignancy diagnosis, when present.

Results.

A total of 618 patients with PsA were included in the study. In particular, 296 were taking anti-tumor necrosis factor-α (anti-TNF) agents and 322 were taking disease-modifying antirheumatic drugs (DMARD). During the observation period, in the total group, 44 patients (7.1%) had a diagnosis of malignancy. Of them, 14 (4.7%; 95% CI 2.8–7.8; 0.52/100 patient-yrs) received anti-TNF therapy and 30 (9.3%; 95% CI 6.6–13.0; 1.03/100 patient-yrs) received traditional DMARD (p = 0.019). However, after adjusting for major demographic and clinical characteristics, the difference between the 2 treatments was no longer significant (p = 0.480), and the only predictor of malignancy occurrence was age (HR 1.04, 95% CI 1.009–1.073, p = 0.012).

Conclusion.

Data from this study confirm that biological therapies do not lead to any increased risk for cancer development, when adequately administered and with proper followup.

Safety and efficacy of anti-tumor necrosis factors α in patients with psoriasis and chronic hepatitis C

Up to date, in literature, it is still debated the role of anti-tumor necrosis factors (TNF)-α treatments in hepatitis C virus (HCV) patients. TNF-α performs a lot of functions, it is an important pro-inflammatory cytokine and it is involved in the host’s immunity. Since TNF-α is implicated in the apoptotic signaling pathway of hepatocytes infected by HCV, anti TNF-α therapy may increase the risk of viral replication or their reactivation. However the treatment of anti TNF-α could have a healthful role because TNF-α appears to be engaged in the pathogenesis of liver fibrosis, inducing apoptotic pathways. We describe the case of a patient with plaque-type psoriasis and concomitant chronic HCV, who was treated successfully with anti-TNF agents simultaneously to cyclosporine without sign of reactivation of HCV and increase of liver enzymes. Our personal experience shows that anti-TNF-α agents are not only effective but also safe. Furthermore the combination therapy of cyclosporine and anti-TNF-α appears to be well-tolerated and able to reduce the amount of liver enzymes as well as HCV-viral-load. However systematic, large-scale studies with long follow-ups will be needed to confirm our results, in association with close liver function monitoring.

Metabolic syndrome and its relationship with the achievement of minimal disease activity state in psoriatic arthritis patients: an observational study

The aim of the study was to evaluate the influence of metabolic syndrome (MetS) on achieving minimal disease activity (MDA) in psoriatic arthritis (PsA) patients treated with anti-tumor necrosis factor (TNF)-α with a follow-up period of 24 months. A cohort of PsA patients was assessed at the University Federico II of Naples and at University of Padova. For the aim of the present study, patients' data were collected at baseline (T0), at 12 months (T1) and at 24 months (T2). Assessment of metabolic and disease activity parameters was performed at each visit. The NCEP-ACT III criteria were used to identify subjects with MetS and the MDA criteria to evaluate the disease activity. On the basis of the exclusion and inclusion criteria, 330 subjects were included in the study; 134 patients (40.7%) were classified as not having MetS and 196 (59.3%) as having MetS. An inverse association was found between presence of metabolic syndrome and the probability of achieving MDA. Univariate analysis indicated that patients with metabolic syndrome were less likely to achieve MDA than patients without metabolic syndrome (OR 0.45, p < 0.001). This inverse association remained statistically significant in the multivariate regression model (OR 0.56, p < 0.001). Metabolic syndrome is associated with a lower probability of achieving MDA in PsA patients in therapy with anti-TNF-α.

Genetic polymorphisms associated with the inflammatory response in bacterial meningitis

Background

Bacterial meningitis (BM) is an infectious disease that results in high mortality and morbidity. Despite efficacious antibiotic therapy, neurological sequelae are often observed in patients after disease. Currently, the main challenge in BM treatment is to develop adjuvant therapies that reduce the occurrence of sequelae. In recent papers published by our group, we described the associations between the single nucleotide polymorphisms (SNPs) AADAT +401C > T, APEX1 Asn148Glu, OGG1 Ser326Cys and PARP1 Val762Ala and BM. In this study, we analyzed the associations between the SNPs TNF -308G > A, TNF -857C > T, IL-8 -251A > T and BM and investigated gene-gene interactions, including the SNPs that we published previously.

Methods

The study was conducted with 54 BM patients and 110 healthy volunteers (as the control group). The genotypes were investigated via primer-introduced restriction analysis-polymerase chain reaction (PIRA-PCR) or polymerase chain reaction-based restriction fragment length polymorphism (PCR-RFLP) analysis. Allelic and genotypic frequencies were also associated with cytokine and chemokine levels, as measured with the x-MAP method, and cell counts. We analyzed gene-gene interactions among SNPs using the generalized multifactor dimensionality reduction (GMDR) method.

Results

We did not find significant association between the SNPs TNF -857C > T and IL-8 -251A > T and the disease. However, a higher frequency of the variant allele TNF -308A was observed in the control group, associated with changes in cytokine levels compared to individuals with wild type genotypes, suggesting a possible protective role. In addition, combined inter-gene interaction analysis indicated a significant association between certain genotypes and BM, mainly involving the alleles APEX1 148Glu, IL8 -251 T and AADAT +401 T. These genotypic combinations were shown to affect cyto/chemokine levels and cell counts in CSF samples from BM patients.

Conclusions

In conclusion, this study revealed a significant association between genetic variability and altered inflammatory responses, involving important pathways that are activated during BM. This knowledge may be useful for a better understanding of BM pathogenesis and the development of new therapeutic approaches.

Electronic supplementary material

The online version of this article (doi:10.1186/s12881-015-0218-6) contains supplementary material, which is available to authorized users.

The effects of icariine concentration on osteoclasts bone resorption induced by titanium particles in vitro

In artificial joint replacement, osteoclast bone resorption induced by wear debris of the implant is a main reason for aseptic loosening. To extend the life of the prosthesis, detailed mechanisms of aseptic loosening and the ways to prevent it should be explored. The aim of this study was to investigate the in vitro effect of icariine on the bone resorption of osteoclasts induced by titanium particles. Macrophage colony stimulating factor (M-CSF) and receptor activator of NF-kB ligand (RANKL) were used to generate osteoclasts from RAW264.7 precursors. The proliferation of RAW264.7 precursors in the presence of different doses of icariine was evaluated by MTT assay. The cells were treated with titanium particles, titanium particles with icariine and culture medium only (control), respectively. At 48 h after treatment, the expression level of receptor activator of NF-kB (RANK) was detected by ELISA, and messenger RNA (mRNA) levels of tartrate-resistant acid phosphatase (TRAP), matrix metalloproteinase 9 (MMP-9), carbonic anhydrase II (CAII) and Cathepsin K (CtsK) were determined by real-time polymerase chain reaction. Western blot was applied to analyze the expression levels of TRAP, RANK and CtsK. In addition, bone chips were cultured in the above conditions, and Toluidine blue staining was then employed to calculate the number and area of resorption pits in the bone chips. After treatment with icariine, expression level of RANK was significantly decreased in the RAW264.7 cell that induced by titanium particle and its cultural medium, mRNA and protein levels of TRAP, CAII, MMP-9 and CtsK were reduced as well. In addition, the numbers of bone resorption pits and areas on bone slices were both reduced by icariine challenging. Icariine could inhibit bone resorption of osteoclast induced by titanium particle, and it might be used as a promising drug for treating of aseptic loosening.

The environment of regulatory T cell biology: cytokines, metabolites, and the microbiome

Regulatory T cells (Tregs) are suppressive T cells that have an essential role in maintaining the balance between immune activation and tolerance. Their development, either in the thymus, periphery, or experimentally in vitro, and stability and function all depend on the right mix of environmental stimuli. This review focuses on the effects of cytokines, metabolites, and the microbiome on both human and mouse Treg biology. The role of cytokines secreted by innate and adaptive immune cells in directing Treg development and shaping their function is well established. New and emerging data suggest that metabolites, such as retinoic acid, and microbial products, such as short-chain fatty acids, also have a critical role in guiding the functional specialization of Tregs. Overall, the complex interaction between distinct environmental stimuli results in unique, and in some cases tissue-specific, tolerogenic environments. Understanding the conditions that favor Treg induction, accumulation, and function is critical to defining the pathophysiology of many immune-mediated diseases and to developing new therapeutic interventions.

Impact of 24-month treatment with etanercept, adalimumab, or methotrexate on metabolic syndrome components in a cohort of 210 psoriatic arthritis patients

Psoriatic arthritis (PsA) is a chronic inflammatory condition, characterized by an excess of metabolic disorders. Metabolic syndrome (MetS) is a cluster of classic cardiovascular risk factors, due to an imbalance between pro- and anti-inflammatory adipokines. Tumor necrosis factor (TNF)-α is a pro-inflammatory adipocytokine mainly produced by monocytes and macrophages with a central role in inflammatory responses, but it also induces adipocytes apoptosis, promotes insulin resistance, and stimulates lipolysis. The aim of this study was to evaluate the impact of therapy with etanercept (ETN), adalimumab (ADA), and methotrexate (MTX) on MetS components in a cohort of PsA patients with a follow-up period of 24 months. A retrospective study has been conducted in a cohort of PsA patients. On the basis of the inclusion criteria, we identified the first 70 consecutive patients, respectively, on ADA, ETN, and MTX, for a total of 210 patients achieving PsARC criteria during the observation period. As part of the routine clinical practice, assessment of metabolic parameters and of disease activity was recorded at baseline (T0), at 12 months (T1), and at 24 months (T2). The results show that when the specific components of the MetS were considered, taking also into account by regression analysis the effect of the confounding factors, the patients on etN and ADA show a significant improvement of the metabolic syndrome components (in detail, waist circumference, triglycerides, high-density lipoprotein cholesterol, and glucose) as compared to the MTX group. In conclusion, these data suggest that the biologic treatment in PsA can no longer be taken into consideration only for its positive effect on articular and cutaneous symptoms but also on the various aspects of this complex picture.

The Therapeutic Potential of Anti-Interleukin-20 Monoclonal Antibody

Interleukin (IL)-20, a member of the IL-10 family of cytokines, was discovered in 2001. IL-20 acts on multiple cell types by activating on a heterodimer receptor complex of either IL-20R1–IL-20R2 or IL-22R1–IL-20R2. Recent evidence indicates that IL-20's interaction with its receptors might have proinflammatory effects on chronic inflammatory diseases, particularly rheumatoid arthritis (RA), osteoporosis, and breast cancer. Updated information about IL-20, such as its identification, expression, receptors, signaling, and biological activities, is illustrated in this review based on our research and the data available in the literature. IL-20 is a pleiotropic cytokine, which promotes inflammation, angiogenesis, and chemotaxis. IL-20 also regulates osteoclast differentiation by altering the receptor activator of NF-κB (RANK) and RANK ligand (RANKL) axis. Inflammation, angiogenesis, and osteoclastogenesis are critical for the pathogenesis of RA, osteoporosis, and breast cancer-induced osteolysis. Based on the in vitro and in vivo data and clinical samples, we demonstrated that IL-20 plays pivotal roles in these three diseases. In experimental models, anti-IL-20 monoclonal antibody ameliorates arthritis severity, protects against ovariectomized-induced bone loss, and inhibits breast tumor-induced osteolysis. This review presents the clinical implications of IL-20, which will lead to a better understanding of the biological functions of IL-20 in these diseases and provide new therapeutic options in the future.

The use of TNF-α blockers in psoriatic arthritis patients with latent tuberculosis infection

Psoriatic arthritis (PsA) is an inflammatory arthropathy associated with skin and/or nail psoriasis. TNF-α is an essential cytokine for the host defense, and its depletion by treatment may facilitate the risk of infections or their reactivation. The aim of this study was to evaluate the efficacy and safety of TNF-α blockers in patients with PsA and concomitant latent tuberculosis infection (LTBI) comparing their outcome with non-infected PsA patients. This is a retrospective study in 321 patients with PsA, attending the Psoriatic Arthritis Clinic at the University Federico II of Naples, who had an inadequate response to DMARDs and started therapy with TNF-α blockers. We identified 40 patients with LTBI, who were included in this study along with 40 not infected PsA patients as control group. At baseline (T0) and every 3 months for 2 years (T2), data concerning PsA activity were registered. All patients underwent chest X-ray every 6 months (or 12 if appropriate). In each group, 22 patients were on etanercept therapy, 14 on adalimumab, and 4 on infliximab. Anti-TNF-α therapy was effective in both group of patients, and no statistically significant differences were found in the analysis of the study variables between the two groups from T0 to T2. No serious adverse events occurred in both groups, and no patient was withdrawn from therapy. Our experience suggests that anti-TNF-α treatment is effective and safe in PsA patients with concomitant LTBI. Therefore, neither LTBI nor chemoprophylaxis seems to influence the course of anti-TNF-α therapy.

Cytosolic phospholipase A2 regulates TNF-induced production of joint destructive effectors in synoviocytes

INTRODUCTION

Rheumatoid arthritis (RA) is an inflammatory disease of the joint characterized by chronic synovitis causing pain, swelling and loss of function due to destruction of cartilage and bone. The complex series of pathological events occurring in RA is largely regulated via excessive production of pro-inflammatory cytokines, the most prominent being tumor necrosis factor (TNF). The objective of this work was to elucidate possible involvement of group IVA cytosolic phospholipase A2 (cPLA2α) in TNF-induced regulation of synovitis and joint destructive effectors in RA, to evaluate the potential of cPLA2α as a future therapeutic target.

METHODS

The involvement of cPLA2α in tumor necrosis factor (TNF)-induced intracellular signaling cascades in synoviocytes (synovial fibroblast-like cells) was analyzed by arachidonic acid (AA) release assay, synoviocyte enzyme activity assay, gene expression analysis by real-time PCR and ELISA immunoassay for the detection of prostaglandin E2 (PGE2), interleukin 8 (IL8) and stromelysin-1 (MMP3), respectively.

RESULTS

Inhibitors of cPLA2α enzyme activity (AVX002, ATK) significantly reduced TNF-induced cellular release of AA, PGE2, IL8 and MMP3. This reduction was evident both at transcriptional, protein or metabolite levels. Interestingly, cPLA2α inhibition affected several key points of the arachidonyl cascade; AA-release, cyclooxygenase-2 (COX2) expression and PGE2 production. Furthermore, the results suggest that cPLA2α is subject to transcriptional auto-regulation as inhibition of cPLA2α resulted in reduced PLA2G4A gene expression in TNF-stimulated synoviocytes.

CONCLUSIONS

cPLA2α appears to be an important regulator of central effectors of inflammation and joint destruction, namely MMP3, IL8, COX2, and PGE2. Decreased transcription of the PLA2G4A and COX2 genes in response to cPLA2α enzyme inhibition further suggest a self-reinforcing effect of cPLA2α inhibition in response to TNF. Collectively, these results support that cPLA2α is an attractive therapeutic target candidate as its inhibition reduces the production of multiple key pro-inflammatory factors involved in RA pathogenesis.

Psoriatic arthritis: advances in pharmacotherapy based on molecular target

The progress on the improved understanding of disease pathogenesis and molecular biology has changed the understanding of disease profiles, emphasizing aspects that simple clinical observation could not identify, and demarcating differences between clinical pictures that seemed to overlap. An example of this spectacular evolution is represented by psoriatic arthritis (PsA). This increase of knowledge on pathogenesis has led to an important impact on therapeutic approach. Therapies are now taken into account because their precise target is known. The authors describe treatment guidelines and revisit traditional therapies as well as innovative therapies in PsA.

Monitoring of adalimumab and antibodies-to-adalimumab levels in patient serum by the homogeneous mobility shift assay

This report describes the analytical validation and application of the homogeneous mobility shift assay (HMSA) method for the measurement of adalimumab and human antibodies-to-adalimumab (ATA) in serum samples from patients who have lost response to adalimumab treatment. Validation of the ATA- and the adalimumab-HMSA revealed a lower limit of detection to be 0.026 U/mL for ATA and 0.018 μg/mL for adalimumab in serum samples. Intra-assay and inter-assay precision determination yielded a coefficient of variation of less than 15%, and the accuracy of both assays was within 20%. Adalimumab drug tolerance in the ATA-HMSA was up to 20 μg/mL in the test serum. Serum samples from 100 drug-naïve healthy subjects were tested to set-up the cut point of 0.55 U/mL for ATA and 0.68 μg/mL for adalimumab. Analysis of 100 serum samples from patients who were losing response to adalimumab showed that 26% had an adalimumab level below the cut point, of these 68% were ATA positive. Overall, 44% of the patients (44/100) were positive for ATA. This study presents evidence that drug and anti-drug antibody levels are important determinants of patient response to therapy.

Development and validation of a homogeneous mobility shift assay for the measurement of infliximab and antibodies-to-infliximab levels in patient serum

Antibody-based drugs such as infliximab (IFX) are effective for the treatment of inflammatory bowel disease (IBD) and other immune-mediated disorders. The development of antibodies against these drugs may result in unfavorable consequences, including the loss of drug efficacy, hypersensitivity reactions, and other adverse events. Therefore, accurate monitoring of serum drug and anti-drug antibody levels should be an important part of therapy for patients being treated with an antibody-based drug. Current methods for the assessment of anti-drug antibodies and drug levels, involving various bridging ELISA and radioimmunoassay techniques, are limited by their sensitivity, interference, and/or complexity. To overcome these limitations, we have developed a non-radiolabeled homogeneous mobility shift assay (HMSA) to measure the antibodies-to-infliximab (ATI) and IFX levels in serum samples. Full method validation was performed on both the ATI- and IFX-HMSA, and the clinical sample test results were also compared with those obtained from a bridging ELISA method to evaluate the difference in performance between the two assays. Validation of the ATI-HMSA revealed a lower limit of quantitation of 0.012 μg/mL in serum. The linear range of quantitation was 0.029-0.54 μg/mL. The intra- and inter-assay precision was less than 20% of coefficient of variation (CV), and the accuracy (% error) of the assay was less than 20%. In serum samples, ATI as low as 0.036 μg/mL can be measured, even in the presence of 60 μg/mL of IFX in the serum. Sera from 100 healthy subjects were tested to determine the cut point of the assay. ATI-positive samples that had been previously analyzed by using a bridging ELISA from 100 patients were also measured by the new method. There was a high correlation between the two methods for ATI levels (p<0.001). Significantly, the new method identified five false-positive samples from the bridging ELISA method. Validation of the mobility shift IFX assay also showed high assay sensitivity, precision and accuracy. The HMSA method may also be applied to other protein-based drugs to accurately detect serum drug and anti-drug antibody levels.

Activation of Sirt1 by resveratrol inhibits TNF-α induced inflammation in fibroblasts

Inflammation is one of main mechanisms of autoimmune disorders and a common feature of most diseases. Appropriate suppression of inflammation is a key resolution to treat the diseases. Sirtuin1 (Sirt1) has been shown to play a role in regulation of inflammation. Resveratrol, a potent Sirt1 activator, has anti-inflammation property. However, the detailed mechanism is not fully understood. In this study, we investigated the anti-inflammation role of Sirt1 in NIH/3T3 fibroblast cell line. Upregulation of matrix metalloproteinases 9 (MMP-9), interleukin-1beta (IL-1β), IL-6 and inducible nitric oxide synthase (iNOS) were induced by tumor necrosis factor alpha (TNF-α) in 3T3 cells and resveratrol suppressed overexpression of these pro-inflammatory molecules in a dose-dependent manner. Knockdown of Sirt1 by RNA interference caused 3T3 cells susceptible to TNF-α stimulation and diminished anti-inflammatory effect of resveratrol. We also explored potential anti-inflammatory mechanisms of resveratrol. Resveratrol reduced NF-κB subunit RelA/p65 acetylation, which is notably Sirt1 dependent. Resveratrol also attenuated phosphorylation of mammalian target of rapamycin (mTOR) and S6 ribosomal protein (S6RP) while ameliorating inflammation. Our data demonstrate that resveratrol inhibits TNF-α-induced inflammation via Sirt1. It suggests that Sirt1 is an efficient target for regulation of inflammation. This study provides insight on treatment of inflammation-related diseases.

Anti-Inflammatory Drug Design Using a Molecular Hybridization Approach

The design of new drugs with better physiochemical properties, adequate absorption, distribution, metabolism, and excretion, effective pharmacologic potency and lacking toxicity remains is a challenge. Inflammation is the initial trigger of several different diseases, such as Alzheimer's disease, asthma, atherosclerosis, colitis, rheumatoid arthritis, depression, cancer; and disorders such as obesity and sexual dysfunction. Although inflammation is not the direct cause of these disorders, inflammatory processes often increase related pain and suffering. New anti-inflammatory drugs developed using molecular hybridization techniques to obtain multiple-ligand drugs can act at one or multiple targets, allowing for synergic action and minimizing toxicity. This work is a review of new anti-inflammatory drugs developed using the molecular modification approach.

Effect of TNF-α production inhibitors on the production of pro-inflammatory cytokines by peripheral blood mononuclear cells from HTLV-1-infected individuals

Human T lymphotropic virus type 1 (HTLV-1) is the causal agent of myelopathy/tropical spastic paraparesis (HAM/TSP), a disease mediated by the immune response. HTLV-1 induces a spontaneous proliferation and production of pro-inflammatory cytokines by T cells, and increasing interferon-γ (IFN-γ) and tumor necrosis factor-α (TNF-α) levels are potentially involved in tissue damage in diseases related to HTLV-1. This exaggerated immune response is also due to an inability of the natural regulatory mechanisms to down-modulate the immune response in this group of patients. TNF-α inhibitors reduce inflammation and have been shown to improve chronic inflammatory diseases in clinical trials. The aim of this study was to evaluate the ability of pentoxifylline, forskolin, rolipram, and thalidomide to decrease in vitro production of TNF-α and IFN-γ in cells of HTLV-1-infected subjects. Participants of the study included 19 patients with HAM/TSP (mean age, 53 ± 11; male:female ratio, 1:1) and 18 HTLV-1 carriers (mean age, 47 ± 11; male:female ratio, 1:2.6). Cytokines were determined by ELISA in supernatants of mononuclear cell cultures. Pentoxifylline inhibited TNF-α and IFN-γ synthesis with the minimum dose used (50 µM). The results with forskolin were similar to those observed with pentoxifylline. The doses of rolipram used were 0.01-1 µM and the best inhibition of TNF-α production was achieved with 1 µM and for IFN-γ production it was 0.01 µM. The minimum dose of thalidomide used (1 µM) inhibited TNF-α production but thalidomide did not inhibit IFN-γ production even when the maximum dose (50 µM) was used. All drugs had an in vitro inhibitory effect on TNF-α production and, with the exception of thalidomide, all of them also decreased IFN-γ production.

The role of Tumor Necrosis Factor-alpha (TNF-α) in the pathogenesis of systemic lupus erythematosus

The Tumor Necrosis Factor-alpha (TNF-α) is a pleiotropic cytokine that produces different stimuli in various physiological and pathological conditions. TNF-α contributes importantly to the development of T cells, B cells, and dendritic cells. However, TNF-α is also a potent inflammatory mediator and apoptosis inducer. The significance of the TNF-α involvement in the pathogenesis of systemic lupus erythematosus (SLE) remains controversial. From the genetic standpoint, a number of studies suggest that the TNF-α gene polymorphism is involved in the susceptibility of SLE. Moreover, there is a close association between the TNF-α gene expression and clinical manifestations. In addition, the increased serum level of TNF-α is observed in SLE patients and associated with disease activity and certain systemic manifestations. Treatment with anti-TNF agents is, however, controversial in SLE since induction of antinuclear antibodies, anti-dsDNA, anticardiolipin antibodies, and cases of drug-induced lupus have been observed in rheumatoid arthritis patients. In this context, this study reviewed the importance of TNF-α in the pathogenesis of SLE.

Therapeutic approaches for tumor necrosis factor inhibition

Tumor necrosis factor (TNF) consists of an inflammatory cytokine essential for homeostasis and organism defense. Despite its physiological relevance, both increased biosynthesis and release of TNF lead to the exacerbation of inflammatory and oxidative responses, which are related to the pathogenesis of a host of diseases of an inflammatory, autoimmune and/or infectious nature. In this context, effective therapeutic approaches for the modulation of TNF have been the focus of research efforts. Approximately one million individuals worldwide have been treated with biotechnological inhibitors of this cytokine, the so-called anti-TNF biopharmaceuticals. However, given the high risk of infection and the limitations related to cost and administration routes, new therapeutic approaches aimed at biological targets that directly or indirectly modulate the production and/or activation of TNF appear promising alternatives for the discovery of new anti-inflammatory and immunomodulatory orally active drugs and are therefore discussed in this paper.

Effect of peroxisome proliferator-activated receptor gamma agonist (pioglitazone) and methotrexate on disease activity in rheumatoid arthritis (experimental and clinical study)

OBJECTIVE

To investigate the combined effect of both pioglitazone and methotrexate on disease activity of rheumatoid arthritis in a biphasic study; experimental and clinical.

METHODS

EXPERIMENTALLY: 50 rats were divided into 5 equal groups; controls, experimental arthritis, methorexate treated (0.1 mg/Kg daily), pioglitazone-treated (10 mg/kg daily), and methotrexate and pioglitazone treated. Clinically: forty-nine diabetic rheumatoid arthritis patients were included. Patients group consisted of 28 patients and they received pioglitazone 30 mg orally beside their usual treatment. Control group consisted of 21 patients and they continued their usual treatment plus placebo. Disease activity was assessed using DAS28 score. Patients were followed up for 3 months.

RESULTS

Pioglitazone produced a significant improvement of serum oxidative stress parameters (P < 0.05), and inflammatory cytokines in the treated arthritic group (P < 0.05). Clinically, the pioglitazone treated group showed significant improvement in DAS28 (P = 0.001) and C-reactive protein (P < 0.0001) compared to placebo group.

CONCLUSION

The concomitant use of the PPAR γ agonist pioglitazone and methotrexate appears to be promising therapeutic strategy for rheumatoid arthritis patients.

Emerging small molecule and biological therapeutic approaches for the treatment of autoimmunity

IMPORTANCE OF THE FIELD

Biological therapeutics targeting TNF-α, IL-6, CD20 and CD80/86 is proving to be an important weapon in the clinicians' armory to fight autoimmunity alongside long-standing small molecule therapeutics such as methotrexate and glucocorticoids. However, there still remains a high unmet clinical need in the field of autoimmunity and many researchers are continuing to discover and develop new therapeutics to address this.

AREAS COVERED IN THIS REVIEW

A new wave of small molecule and biological therapeutics targeting different pathways is being developed which could generate exciting new options for clinicians. This review aims to highlight those emerging therapies that are most advanced in clinical development.

WHAT THE READER WILL GAIN

The reader will gain an appreciation of new approaches being developed to address the high unmet clinical need in the field of autoimmunity.

TAKE HOME MESSAGE

Despite recent success in the development of therapeutics to treat autoimmunity, new therapeutic strategies are being developed to address the remaining areas of a high unmet clinical need.

Immunogenicity of Anti-TNF-alpha agents in autoimmune diseases

Prognosis of several autoimmune diseases, especially rheumatoid arthritis (RA), ankylosing spondylitis, Crohn's disease (CD), and psoriasis, usually refractory to conventional treatment improved considerably with the introduction of tumor necrosis factor alpha (TNF-alpha) antagonistic agents, which is now available (infliximab, etanercept, and adalimumab). However, a portion of patients persists with active disease, infusion reactions, and relapses even during current biological therapy. One of the reasons for this is the associated immunogenicity to these drugs. The incentive for induction of antibodies against anti-TNF-alpha agent depends mainly on its constitution. Chimerical drugs have a higher capacity of inducing immunogenicity compared to completely human drugs. Among the three anti-TNF-alpha agents, this phenomenon has been studied mainly in patients using infliximab, especially in RA and CD. The prevalence of anti-infliximab antibodies in RA varies from 12% to 44% and seems to be inversely proportional to the level of seric infliximab and therapeutic response. The use of etanercept was associated to the development of anti-etanercept antibodies in 0% to 18% of patients, without apparent effect on effectiveness or adverse events. Studies with RA and CD patients show prevalence of anti-adalimumab antibodies from 1% to 87%. Immunosuppressive drug addiction can reduce the induction of anti-TNF-alpha antibodies.

Association of TNF-alpha gene polymorphisms with systemic lupus erythematosus in Taiwanese patients

Tumour necrosis factor-alpha (TNF-alpha), an important proinflammatory cytokine, exerts a variety of physiological and pathogenic effects that lead to tissue destruction. Studies on the association of TNF-alpha genetic polymorphisms with systemic lupus erythematosus (SLE) have yielded inconclusive results. We investigated the association of TNF-alpha genetic polymorphisms (-1031T/C, -863C/A, -857T/C, -308A/G and +489A/G) with SLE in Taiwanese patients and controls. Our results indicate that 1) the frequency of the A-allele at -863 position was significantly higher in SLE patients (odds ratio = 1.46; 95% CI = 1.02-2.08); 2) the frequency of the A-allele at +489 position was significantly higher in SLE patients (odds ratio = 1.79; 95% CI = 1.21-2.65); 3) the AA or GA genotype frequencies at +489 position were significantly increased in SLE patients (AA genotype: odds ratio = 11.20; 95% CI = 1.36-92.55; GA genotype: odds ratio = 1.63; 95% CI = 1.03-2.58); 4) no significant association of TNF-alpha haplotypic distributions was observed, except for the haplotypes TCCGA, CACGA and CCCGG; and 5) the genotype frequency of the polymorphisms at -1031 was significantly different in patients with antinuclear antibodies (P = 0.022). The allele and genotype frequencies of the polymorphisms at -863 were not significantly different. The genotype frequency of the polymorphisms at -857 was significantly different in patients with haematological disorder (P = 0.025). The frequency of A allele of the polymorphisms at -308 was significantly increased in patients with malar rash (P = 0.033), discoid rash (P = 0.023), photosensitivity (P = 0.037), oral ulcers (P = 0.002) and serositis (P = 0.029). The genotype frequency of the polymorphisms at +489 was significantly different in patients with discoid rash and photosensitivity (data not shown; discoid rash, P = 0.031; photosensitivity, P = 0.044). These results suggest that TNF-alpha genetic polymorphisms contribute to SLE susceptibility in the Taiwanese population.

SD0006: a potent, selective and orally available inhibitor of p38 kinase

SD0006 is a diarylpyrazole that was prepared as an inhibitor of p38 kinase-alpha (p38alpha). In vitro, SD0006 was selective for p38alpha kinase over 50 other kinases screened (including p38gamma and p38delta with modest selectivity over p38beta). Crystal structures with p38alpha show binding at the ATP site with additional residue interactions outside the ATP pocket unique to p38alpha that can confer advantages over other ATP competitive inhibitors. Direct correlation between inhibition of p38alpha activity and that of lipopolysaccharide-stimulated TNFalpha release was established in cellular models and in vivo, including a phase 1 clinical trial. Potency (IC(50)) for inhibiting tumor necrosis factor-alpha (TNFalpha) release, in vitro and in vivo, was <200 nmol/l. In vivo, SD0006 was effective in the rat streptococcal-cell-wall-induced arthritis model, with dramatic protective effects on paw joint integrity and bone density as shown by radiographic analysis. In the murine collagen-induced arthritis model, equivalence was demonstrated to anti-TNFalpha treatment. SD0006 also demonstrated good oral anti-inflammatory efficacy with excellent cross-species correlation between the rat, cynomolgus monkey, and human. SD0006 suppressed expression of multiple proinflammatory proteins at both the transcriptional and translational levels. These properties suggest SD0006 could provide broader therapeutic efficacy than cytokine-targeted monotherapeutics.

Rapamycin-treated mature dendritic cells have a unique cytokine secretion profile and impaired allostimulatory capacity

Rapamycin (RAPA, sirolimus) is a recently introduced immunosuppressive agent. Its effect on the differentiation and antigen uptake of immature dendritic cells (iDCs) has been studied. However, whether it can also modulate the function of mature DCs (mDCs) is unknown. We investigated the effects of RAPA on rat bone marrow-derived DCs at different stages of maturation. RAPA affected maturation, increased apoptosis and reduced lipopolysaccharide (LPS)-induced IL-12 and IL-10 production in iDCs. However, mDCs were resistant to RAPA-induced apoptosis. RAPA-mDCs produced significantly less IL-10 and TNF-alpha when compared with mature DCs but similar amounts of IL-12. RAPA did not affect constitutive NF-kappaB activity, but inhibited allostimulatory activity in mature DCs. In conclusion, mDCs treated with RAPA are reprogrammed to produce a unique cytokine secretion profile and exhibit low allostimulatory capacity, which may play an important role in rapamycin-based immunomodulation.

Nociceptive and inflammatory responses induced by formalin in the orofacial region of rats: effect of anti-TNFalpha strategies

This study evaluated the effects of different anti-TNFalpha strategies on the nociceptive and inflammatory responses triggered by formalin in the rat orofacial region. Formalin injection (2.5%) into the right upper lip caused a nociceptive response that was biphasic, with the first phase observed between 0 and 3 min and the second phase between 12 and 30 min. Plasma extravasation induced by formalin was time-related and reached the peak at 360 min. The monoclonal antibody anti-TNFalpha (25 and 50 pg/lip) significantly inhibited the second phase of formalin-induced nociceptive behavior, while the first phase remained unaltered. The systemic treatment with the chimeric anti-TNFalpha antibody infliximab also caused a significant inhibition of the second phase. Interestingly, the local administration of infliximab (50 pg/lip) produced a significant reduction of both phases of formalin-induced nociception. In addition, the systemic pretreatment with the preferential inhibitor of TNFalpha synthesis thalidomide (25 and 50 mg/kg, p.o) promoted a marked reduction of the first and second phases of formalin-evoked nociception. The local administration of the monoclonal antibody anti-TNFalpha (25 and 50 pg/lip) or infliximab (50 pg/lip) markedly reduced the plasma extravasation induced by formalin. Otherwise, formalin-elicited plasma extravasation was not significantly affected by the systemic administration of either infliximab (1 mg/kg; s.c) or thalidomide (50 mg/kg, p.o). Present data suggest that blocking TNFalpha effects, through different pharmacological tools, could represent a good alternative to control orofacial inflammatory pain that is refractory to other drugs.

Development and biological evaluation of C(60) fulleropyrrolidine-thalidomide dyad as a new anti-inflammation agent

Research studies in the field of C(60) fullerene derivatives have significantly increased due to the broad range of biological activities that were found for these compounds. We designed and prepared a new C(60) fullerene hybrid bearing thalidomide as a potential double-action anti-inflammatory agent, capable of simultaneous inhibition of LPS-induced NO and TNF-alpha production. The C(60) fulleropyrrolidine-thalidomide dyad, CLT, was an effective agent to suppress the release of NO and TNF-alpha by the LPS-stimulated macrophages RAW 264.7. Ten micromolars of CLT effectively inhibited LPS-induced NO and TNF-alpha production by 47.3+/-4.2% and 70.2+/-4% with respected to the control, respectively. Furthermore, preliminary biochemical investigation revealed that CLT was a potent agent to suppress both LPS-induced intracellular ROS production and iNOS expression, and CLT also inhibited the phosphorylation of ERK which is an important protein kinase involved in the activation of TNF-alpha synthesis in LPS-activated macrophages. We believed that the studies herein would hold promise for future development of a new generation of potent anti-inflammatory agents.

Pentoxifylline down modulate in vitro T cell responses and attenuate pathology in Leishmania and HTLV-I infections

Tumor necrosis factor-alpha (TNF-alpha) is known to have numerous biological properties relating to inflammation. This cytokine participates in the tissue damage of chronic inflammatory, autoimmune and infectious diseases. Pentoxifylline is a methylxanthine that inhibits phosphodiesterase IV, which inhibits the degradation of the cAMP and prostanoids. The increased intracellular concentration of the cAMP leads to a negative regulation of NF-kappaB and NF-AT transcription factors and suppresses TNF-alpha production. This review describes studies that support evidences that TNF-alpha is involved in the pathogenesis of HTLV-1 associated myelopathy and of cutaneous and mucosal leishmaniasis. Additionally, it demonstrates the effect of pentoxifylline in vitro in inhibiting TNF-alpha and IFN-gamma spontaneous production in PBMC from HTLV-1-infected patients, as well as its in vivo effect in inhibiting TNF-alpha in sera from mucosal leishmaniasis patients. Moreover, we review the results of clinical studies from the last 10 years using pentoxifylline to treat HTLV-1 associated myelopathy and cutaneous and mucosal leishmaniasis.