Impact of treatment with infliximab on serum cytokine profile of patients with rheumatoid and psoriatic arthritis

The influence of tumour necrosis factor α inhibitors treatment - etanercept on serum concentration of biomarkers of inflammation and cartilage turnover in psoriatic arthritis patients

INTRODUCTION

Effective treatment in psoriatic arthritis (PsA) patients can protect them from severe musculoskeletal complications. For appropriate monitoring of anti-tumour necrosis factor α (anti-TNF-α) treatment in PsA, specific biomarkers are needed.

AIM

To investigate whether biological treatment with anti-TNF-α (etanercept 50 mg once a week subcutaneously) affects the activity of selected mediators of inflammation and destruction of articular cartilage: interleukin-6 (IL-6), interleukin-18 (IL-18), matrix metalloproteinases 1 and 3 (MMP-1, MMP-3), cartilage oligomeric matrix protein (COMP), human cartilage glycoprotein (YKL-40) in serum of patients with PsA.

MATERIAL AND METHODS

The study included 25 patients with PsA. The concentration of IL-6, IL-18, MMP-1, MMP-3, COMP and YKL-40 in serum was determined before, and 6 and 12 weeks after the beginning of anti-TNF-α treatment. Clinical severity of the disease according to the Body Surface Area, Psoriasis Area and Severity Index and Dermatology Life Quality Index as well as tender and swollen joint count (TJC, SJC) were also evaluated.

RESULTS

The study disclosed a statistically significant reduction in the serum concentration of IL-6, MMP-1 and YKL-40 in PsA patients after 6 and 12 weeks from the beginning of anti-TNF-α treatment (p = 0.00018 for IL-6; p = 0.01242 for MMP-1; p = 0.03263 for YKL-40).

CONCLUSIONS

IL-6, MMP-1 and YKL-40 may be useful for monitoring the effectiveness of anti-TNF-α treatment.

Changes in T cell effector functions over an 8-year period with TNF antagonists in patients with chronic inflammatory rheumatic diseases

The aim of the study was to clarify the effect of long-term anti-TNF therapy on T cell function in patients with rheumatologic immune-mediated inflammatory diseases (IMID). The production of IFNγ by T cells was evaluated at baseline and after 1, 2, 4, and 8 years of anti-TNF agents by means of a QuantiFERON-TB Gold In-Tube assay. The T cell proliferation and surface co-expression of CD25/CD134 in response to phytohaemagglutinin together with the in vitro impact of anti-TNF therapy on the functional capacity of T cells were evaluated after 8 years from the onset of the biological treatment. Age-matched healthy donors were enrolled as controls. The quantitative mitogen-induced IFNγ responses significantly increased with respect to baseline at each time point, apart from the determination after 4 years. We found an increased expression of CD25/CD134 in CD4⁺ compared to CD8⁺ T cells both in patients and controls. The in vitro addition of anti-TNF agents induced a significant decrease of both the IFNγ response and of CD25/CD134, whereas no effect on the intensity of the proliferative response was observed. Our data provide a biological basis for the reassuring issues on the safety of long-term anti-TNF treatment in patients with IMID.

A Randomized, Double-Blind, Placebo-Controlled Clinical Trial of Tocilizumab, An Interleukin-6 Receptor Antibody, For Residual Symptoms in Schizophrenia

Evidence from preclinical, epidemiological, and human studies indicates that inflammation, and in particular elevated interleukin-6 (IL-6) activity, may be related to clinical manifestations and pathophysiology of schizophrenia. Furthermore, studies in preclinical models suggest that decreasing IL-6 activity may mitigate or reverse some of these deficits. The purpose of this trial was to test whether an IL-6 receptor antibody, tocilizumab, would improve residual positive and negative symptoms and cognitive deficits in schizophrenia. We randomized 36 clinically stable, moderately symptomatic (i.e., Positive and Negative Syndrome Scale (PANSS) >60) individuals with schizophrenia to 3 monthly infusions of 8 mg/kg tocilizumab or placebo (normal saline). The primary outcome was effect at week 12 on the PANSS Total Score. Effects on the MATRICS, other PANSS subscales, Clinical Global Impression, and Global Assessment of Functioning were secondary outcomes. There were no observed treatment effects on any behavioral outcome measure. Baseline C-reactive protein (CRP) or cytokine levels did not predict treatment outcome, nor were there correlations between changes in these inflammatory markers and the measured outcomes. As expected, IL-6 and IL-8 increased, while CRP decreased, in the tocilizumab group compared with the placebo group. This study did not reveal any evidence that an IL-6 receptor antibody affects behavioral outcomes in schizophrenia. One potential explanation is the lack of capacity of this agent to penetrate the central nervous system. Additional trials of medications aimed at targeting cytokine overactivity that act directly on brain function and/or treatment in early-stage psychosis populations are needed.

Paget's disease of bone: an osteoimmunological disorder?

Osteoimmunology represents a large area of research resulting from the cross talk between bone and immune systems. Many cytokines and signaling cascades are involved in the field of osteoimmunology, originating from various cell types. The RANK/receptor activator of nuclear factor Kappa-B ligand (RANKL)/osteoprotegerin (OPG) signaling has a pivotal role in osteoimmunology, in addition to proinflammatory cytokines such as tumor necrosis factor-α, interleukin (IL)-1, IL-6, and IL-17. Clinically, osteoimmunological disorders, such as rheumatoid arthritis, osteoporosis, and periodontitis, should be classified according to their pattern of osteoimmunological serum biomarkers. Paget’s disease of bone is a common metabolic bone disorder, resulting from an excessively increased bone resorption coupled with aberrant bone formation. With the exception of the cellular responses to measles virus nucleocapsid protein and the interferon-gamma signature, the exact role of the immune system in Paget’s disease of bone is not well understood. The cytokine profiles, such as the increased levels of IL-6 and the interferon-gamma signature observed in this disease, are also very similar to those observed in other osteoimmunological disorders. As a potential osteoimmunological disorder, the treatment of Paget’s disease of bone may also benefit from progress made in targeted therapies, in particular for receptor activator of nuclear factor Kappa-B ligand and IL-6 signaling inhibition.

Cytokines as biomarkers in rheumatoid arthritis

RA is a complex disease that develops as a series of events often referred to as disease continuum. RA would benefit from novel biomarker development for diagnosis where new biomarkers are still needed (even if progresses have been made with the inclusion of ACPA into the ACR/EULAR 2010 diagnostic criteria) and for prognostic notably in at risk of evolution patients with autoantibody-positive arthralgia. Risk biomarkers for rapid evolution or cardiovascular complications are also highly desirable. Monitoring biomarkers would be useful in predicting relapse. Finally, predictive biomarkers for therapy outcome would allow tailoring therapy to the individual. Increasing numbers of cytokines have been involved in RA pathology. Many have the potential as biomarkers in RA especially as their clinical utility is already established in other diseases and could be easily transferable to rheumatology. We will review the current knowledge's relation to cytokine used as biomarker in RA. However, given the complexity and heterogeneous nature of RA, it is unlikely that a single cytokine may provide sufficient discrimination; therefore multiple biomarker signatures may represent more realistic approach for the future of personalised medicine in RA.

Plasma IL-6 levels correlate with clinical and ultrasound measures of arthritis in patients with systemic lupus erythematosus

OBJECTIVE

The objective of this paper is to elucidate the role of specific cytokines in lupus (SLE) arthritis.

METHODS

Fifty SLE and 40 RA patients had an ultrasound (US) scan of their hand as per standardized protocols. US scores were expressed per joint and as a total 'US activity' score, (sum of power Doppler (PD) and grey-scale synovial hypertrophy scores in all joints) and a total erosion score. SLE disease activity was assessed (BILAG and SELENA-SLEDAI). Plasma levels of IL-6, TNF-alpha and BLyS were measured using sandwich ELISA kits (Quantikine kits, R & D).

RESULTS

On the basis of the US results SLE patients were divided into three groups: erosive arthritis (n = 20), non-erosive arthritis (n = 18) and those with a normal US scan (n = 12). Across the SLE groups plasma IL-6 levels correlated with CRP (p < 0.001), hand deformity scores (p = 0.005), BILAG musculoskeletal score (p = 0.009), wrist PD score (p = 0.01), the presence of tenosynovitis (p = 0.008) and total US activity score (p < 0.001) (which remained constant when corrected for total BILAG score). Neither TNF-alpha nor BLyS levels correlated with US or clinical measures of lupus arthritis; however, TNF-alpha correlated with total BILAG score (p < 0.001).

CONCLUSION

This is the first study to examine levels of specific cytokines in a cohort of SLE patients stratified in terms of joint disease by US, where the most significant finding is that IL-6 levels correlated both with clinical and US measures of arthritis disease activity.

The role of p38 MAPK in the aetiopathogenesis of psoriasis and psoriatic arthritis

The pathogenetic mechanisms responsible for the induction of immune-mediated disorders, such as psoriasis, remain not well characterized. Molecular signaling pathways are not well described in psoriasis, as well as psoriatic arthritis, which is seen in up to 40% of patients with psoriasis. Signaling pathway defects have long been hypothesized to participate in the pathology of psoriasis, yet their implication in the altered psoriatic gene expression still remains unclear. Emerging data suggest a potential pathogenic role for mitogen activated protein kinases p38 (p38 MAPK) extracellular signal-regulated kinase 1/2 (ERK1/2), and c-Jun N-terminal kinase (JNK) in the development of psoriasis. The data are still limited, though, for psoriatic arthritis. This review discusses the current data suggesting a crucial role for p38 MAPK in the pathogenesis of these disorders.

-174G/C IL-6 gene promoter polymorphism predicts therapeutic response to TNF-α blockers

BACKGROUND

Although TNF-α blockade is a very effective therapy for psoriasis, not all patients achieve a favorable outcome. The association between IL-6 and psoriasis has been investigated but no papers have focused on the pharmacogenetics of IL-6.

OBJECTIVE

To examine whether the G or the C allele, at position -174 in the promoter of IL-6, influences the relationships between body weight, body composition, and therapeutic response to TNF-α blockers in psoriasis.

METHODS

Sixty patients with psoriasis were studied, at baseline and 6-month follow-up after therapy. Assessment of the -174G/C IL-6 polymorphism, Psoriasis Area and Severity Index and Disease Activity Score-28 scores, body weight (kg), BMI, body composition by Dual-energy X-ray absorptiometry, and systemic inflammation was performed.

RESULTS

Relevant body composition changes occurred after therapy. Normal weight participants showed a greater increase in fat mass than lean mass, compared with obese participants. According to their genotypes, C(+) carriers showed a greater increase in lean mass and fat mass, at the abdominal region, with respect to C(-) carriers. C(+) carriers outweighed C(-) carriers in the group of treatment responders. A higher number of responders were present among normal weight participants, with respect to obese participants. Obesity and the -174G/C IL-6 polymorphism predicted poor response to TNF-α blockers [odds ratio for C(-) carriers, obese: 2.00 (confidence interval: 1.19-3.38; P≤0.05)].

CONCLUSION

Our data show that the G allele of the -174G/C IL-6 polymorphism and obesity can be considered as risk factors for the prognosis and management of psoriasis. This is the first study to suggest the -174G/C IL-6 polymorphism as a novel genetic marker of responsiveness to TNF-α blockers in psoriasis.

Analysis of SF and plasma cytokines provides insights into the mechanisms of inflammatory arthritis and may predict response to therapy

OBJECTIVES

Biologic drugs have revolutionized the care of RA, but are expensive and not universally effective. To further understand the inflammatory mechanisms underlying RA and identify potential biomarkers predicting response to therapy, we measured multiple cytokine concentrations in SF of patients with inflammatory arthritides (IAs) and, in a subset of patients with RA, correlated this with response to TNF-α inhibition.

METHODS

SF from 42 RA patients and 19 non-RA IA patients were analysed for 12 cytokines using a multiplex cytokine assay. Cytokines were also measured in the plasma of 16 RA patients before and following treatment with anti-TNF-α. Data were analysed using Mann-Whitney U-test, Spearman's rank correlation and cluster analysis with the Kruskal-Wallis test with Dunn's post-test analysis.

RESULTS

RA SF contained significantly elevated levels of IL-1β, IL-1ra, IL-2, IL-4, IL-8, IL-10, IL-17, IFN-γ, G-CSF, GM-CSF and TNF-α compared with other IA SF. RA patients who did not respond to anti-TNF therapy had elevated IL-6 in their SF pre-therapy (P < 0.05), whereas responders had elevated IL-2 and G-CSF (P < 0.05). Plasma cytokine concentrations were not significantly modulated by TNF inhibitors, with the exception of IL-6, which decreased after 12 weeks (P < 0.05).

CONCLUSIONS

Cytokine profiles in RA SF vary with treatment and response to therapy. Cytokine concentrations are significantly lower in plasma than in SF and relatively unchanged by TNF inhibitor therapy. Concentrations of IL-6, IL-2 and G-CSF in SF may predict response to TNF inhibitors.

Tissue and serum markers of inflammation during the follow-up of patients with giant-cell arteritis--a prospective longitudinal study

Objective. To evaluate the association between inflammatory markers and relapse in GCA patients longitudinally assessed in a clinical trial of infliximab and glucocorticosteroids.

Methods. Forty-four newly diagnosed GCA patients in glucocorticosteroid-induced remission were randomized to receive infliximab 5 mg/kg or placebo plus daily glucocorticosteroids, tapered using a standardized schedule. Sera were analysed for inflammatory markers at multiple, pre-defined time points. Temporal artery biopsies were performed in four patients before and after treatment to analyse changes in inflammatory and vascular remodelling marker expression.

Results. Thirteen of 44 patients relapsed. Similar proportions of relapsed patients were present in both treatment arms. ESR, CRP, intercellular adhesion molecule (ICAM)-1, TNF-α, and IL-12p40 were significantly elevated near relapse. In post-treatment biopsies, mRNA expression of pro-inflammatory cytokines decreased, while vascular remodelling factors increased relative to baseline biopsies. Tissue IL-12p40 and IFN-γ mRNA remained elevated in relapsing vs remitting patients.

Conclusion. Despite prior findings of high concentrations of TNF-α in temporal artery biopsies of GCA patients, infliximab plus glucocorticosteroids did not result in improved clinical outcomes. Increased measures of this biomarker did not provide useful insight into the relative importance of TNF-α in the pathogenesis of GCA. Gene expression analysis in paired temporal artery biopsies pre- and post-treatment revealed decreased inflammatory activity and active vascular remodelling following treatment. In relapsing patients, increased expression of IFN-γ and IL-12p40 in post-treatment biopsies suggests a role in sustaining disease and setting the stage for relapse during treatment withdrawal.

Trial registration. ClinicalTrials.gov; http://www.clinicaltrials.gov; NCT00076726.

Elevation of serum epidermal growth factor and interleukin 1 receptor antagonist in active psoriasis vulgaris

BACKGROUND

Psoriatic plaques present a complex expression profile, including high levels of cytokines, chemokines and growth factors. Circulating cytokines have been suggested to reflect the activation status of the inflammatory process.

OBJECTIVES

To analyse 20 cytokines, chemokines and growth factors in 14 patients with psoriasis vulgaris at the start and during the course of ultraviolet B treatment.

METHODS

A multiplex cytokine assay was used.

RESULTS

We identified increased serum levels of epidermal growth factor (EGF) (mean 323 vs. 36·6 pg mL⁻¹, P = 0·0001), interleukin (IL)-1 receptor antagonist (mean 39·1 vs. 14·6 pg mL⁻¹, P = 0·02) and tumour necrosis factor-α (mean 7·5 vs. 4·5 pg mL⁻¹, P = 0·04) at baseline in patients with psoriasis compared with matched controls. None of these cytokines was correlated to the severity of the disease (Psoriasis Area and Severity Index) or decreased with phototherapy, suggesting that sources other than lesional skin contribute to the production of these cytokines. Using cluster analysis, we observed coordinate upregulation of EGF, IL-6, macrophage inflammatory protein-1ß and vascular endothelial growth factor.

CONCLUSIONS

The sustained high expression of inflammatory circulating cytokines is a potential mechanism linking psoriasis with its extracutaneous comorbidities.

Serum cytokine concentrations in a patient with rheumatoid arthritis on etanercept therapy who subsequently developed pneumocystis pneumonia: a case report

We report a rheumatoid arthritis patient who was treated with etanercept. Serum levels of tumor-necrosis-factor- (TNF-) alpha, soluble-tumor-necrosis-factor receptor- (sTNFR-) I and -II, interleukin- (IL-) 6, and IL-1 beta were measured by ELISA before and during the course of therapy. While the serum levels of IL-6 and IL-1 beta dropped rapidly following the initiation of therapy, the concentrations of TNF-alpha and sTNFR-II steadily increased to a plateau. Although significant clinical efficacy was observed, etanercept had to be discontinued when after 12 weeks of therapy the patient was found to have pneumocystis pneumonia.

Recent advances in neutralizing the IL-6 pathway in arthritis

Recent advances in understanding the mechanism(s) of how IL-6 trans-signaling regulates immune cell function and promotes inflammation in autoimmune arthritis are critically reviewed. Serum and/or synovial fluid (SF) IL-6 is markedly elevated in adult and juvenile rheumatoid arthritis (RA), psoriatic arthritis (PsA), ankylosing spondylitis (AS) and osteoarthritis (OA). IL-6, in concert with IL-17, determines the fate of CD4⁺ lymphocytes and therefore TH₁₇ cell differentiation. IL-6 also plays a critical role in modulating B-lymphocyte activity. The recognition that IL-6 trans-signaling regulates inflammation resulted in the development of tocilizumab, a fully humanized monoclonal antibody that neutralizes the biological activity of the IL-6-receptor (IL-6R). Significant clinical benefit was demonstrated as well as reduced serum IL-6 levels with suppression of X-ray progression of disease in several clinical trials in which juvenile or adult RA patients were treated with tocilizumab monotherapy or tocilizumab plus methotrexate. However, levels of serum and/or SF IL-6 cytokine protein superfamily members, adiponectin, oncostatin M, pre-B-cell colony enhancing factor/visfatin and leukemia inhibitory factor are also elevated in RA. Additional studies will be required to determine if anti-IL-6 trans-signaling inhibition strategies with tocilizumab or recombinant soluble IL-6R reduce the level of these cytokines.