Does vascular endothelial growth factor in the rheumatoid synovium predict joint destruction? A clinical, radiological, and pathological study in 12 patients monitored for 10 years

Angiopoietin-2 is highly correlated with inflammation and disease activity in recent-onset rheumatoid arthritis and could be predictive for cardiovascular disease

OBJECTIVE

To investigate whether serum levels of endothelial cell activation markers in early RA patients can serve as biomarkers for inflammation and disease activity, and are associated with radiological progression and development of cardiovascular disease (CVD).

METHODS

Serum levels of VEGF, soluble vascular cell adhesion molecule (sVCAM)-1 and angiopoietin-2 (Angpt-2) were measured by ELISA in 176 patients with recent-onset RA, at the time of diagnosis and after 2 years. Markers of inflammation and disease activity were assessed, as well as radiological damage of hands and feet, at diagnosis and after 2 years. Prevalence of CVD of all patients after 12.5 years disease duration was retrieved from medical records.

RESULTS

Patients with RA had higher levels of VEGF and Angpt-2 at disease onset compared with healthy controls, which correlated with markers of inflammation, but were not predictive of radiological progression after 2 years. Angpt-2 levels, moreover, significantly correlated with measures of disease activity. Nearly 18% of RA patients developed CVD after an average of 12.5 years of disease, and these patients had a significantly higher level of Angpt-2 at the onset of RA compared with patients who did not develop CVD.

CONCLUSIONS

In early RA, markers of endothelial activation are highly correlated with inflammation and disease activity, but not with radiological progression. Angpt-2 could be predictive for the development of CVD since Angpt-2 levels were significantly higher in CVD patients than in non-CVD patients.

Inhibition of HIF-1alpha activity by BP-1 ameliorates adjuvant induced arthritis in rats

Rheumatoid arthritis (RA) is a chronic inflammatory, angiogenic disease. Inflamed synovitis is a hallmark of RA which is hypoxic in nature. Vascular endothelial growth factor (VEGF), one of the key regulators of angiogenesis, is overexpressed in the pathogenesis of RA. VEGF expression is regulated by hypoxia-inducible factor-1alpha (HIF-1alpha), a master regulator of homeostasis which plays a pivotal role in hypoxia-induced angiogenesis. In this study we show that synthetic benzophenone analogue, 2-benzoyl-phenoxy acetamide (BP-1) can act as a novel anti-arthritic agent in an experimental adjuvant induced arthritis (AIA) rat model by targeting VEGF and HIF-1alpha. BP-1 administered hypoxic endothelial cells and arthritic animals clearly showed down regulation of VEGF expression. Further, BP-1 inhibits nuclear translocation of HIF-1alpha, which in turn suppresses transcription of the VEGF gene. These results suggest a further possible clinical application of the BP-1 derivative as an anti-arthritic agent in association with conventional chemotherapeutic agents.

Angiogenesis as a therapeutic target in arthritis: learning the lessons of the colorectal cancer experience

The idea of a therapeutic modality aimed at 'starving' a tissue of blood vessels, and consequentially of oxygen and nutrients, was born from the concept that blood vessel formation (angiogenesis) is central to the progression and maintenance of diseases which involve tissue expansion/invasion. In the first instance, solid malignancies were the target for anti-angiogenic treatments, with colorectal cancer being the first disease for which an angiogenesis inhibitor--anti-vascular endothelial growth factor antibody bevacizumab--was approved in 2004. Our understanding of the pathogenesis of rheumatoid arthritis (RA) has lead to many parallels being drawn between this chronic inflammatory disease and solid tumours, in that both involve tissue expansion, invasion, expression of cytokines and growth factors and areas of hypoxia/hypoperfusion. As a result, angiogenesis blockade has been touted as a possible treatment for RA. The lessons learnt during the progression of eventually successful therapies such as bevacizumab should undoubtedly guide us in the future development of comparable treatments for RA.

Drugs to suppress cough

Cough is an important defensive reflex of the airway and also a common symptom of respiratory disease. Cough after common respiratory virus infection is transient but is more persistent when associated with conditions such as asthma, rhinosinusitis, gastro-oesophageal reflux, chronic obstructive pulmonary disease and lung cancer. Persistent cough may be due to peripheral and/or central sensitisation of cough reflexes initiated by cough receptors, rapidly adapting receptors or nociceptors. Treatment directed at associated conditions such as asthma (with anti-inflammatories) and gastro-oesophageal reflux (with proton-pump inhibitors) improve cough. There remains a need to use drugs that suppress the neural activity of cough (termed nonspecific), as treatments directed at the clinical cause(s) of the underlying cough (termed specific) may not be effective. The most effective indirect antitussives are opioids such as morphine, codeine or pholcodeine, but they produce side effects such as drowsiness, nausea, constipation and physical dependence. Opioids such as kappa- and delta-receptor agonists, non-opioids such as nociceptin, neurokinin and bradykinin receptor antagonists, cannabinoids, vanilloid receptor-1 antagonists, blockers of Na+-dependent channels, and large conductance Ca2+-dependent K+-channel activators of afferent nerves may represent novel antitussives.

Anti-TNF-α antibody Infliximab and glucocorticoids reduce serum vascular endothelial growth factor levels in patients with rheumatoid arthritis: a pilot study

To compare the effect of oral glucocorticoid (GC) therapy with the effect of intravenous anti-TNF-alpha-therapy on serum VEGF levels of patients with rheumatoid arthritis (RA). Five RA patients (5/8) who had no prior treatment with DMARDs (Disease modifying antirheumatic drugs) or GCs were administered 20 mg prednisolone daily. Three patients who failed more than one DMARD therapy received infusion with Infliximab (200 mg). VEGF-serum levels were measured by enzyme-linked immunosorbent assay before treatment,and at day 10 or 13 during prednisolone therapy, or 14 days after the first Infliximab infusion. Serum VEGF levels in therapy naive RA patients (GC group) were higher than those in pretreated patients who received Infliximab (median serum VEGF level: 1106 vs 320 pg/ml; P=0.1). Treatment with Infliximab as well as GCs significantly decreased serum VEGF levels after 10-14 days in RA patients (median serum VEGF level after treatment: GC group 559 pg/ml, Infliximab group 92 pg/ml; P=0.01 vs without treatment or preinfusion).

CONCLUSIONS

Anti-TNF-alpha antibody Infliximab as well as GC are able to decrease serum VEGF levels in patients with active RA. Whether therapeutic reduction of serum VEGF levels is associated with inhibition of angiogenesis should be evaluated in future by imaging of synovial vasculature.

New antiangiogenic strategies for the treatment of proliferative synovitis

Angiogenesis inhibition, which has been extensively studied for the treatment of various malignancies, is beginning to emerge as a new potential therapy for proliferative synovitis, particularly rheumatoid arthritis (RA). The rheumatoid pannus, the site of inflammation and joint destruction in the rheumatoid synovium, relies on the development of new vasculature to sustain its growth. A host of mediators have been shown to induce angiogenesis at the site of the inflamed synovium; these include vascular endothelial growth factor, fibroblast growth factor, integrin alpha(V)beta3, angiopoietin, prosta-glandin E1 and prostaglandin E2, and matrix metalloproteinases. In addition, hypoxia at the site of synovial inflammation contributes to angiogenesis stimulation. Several naturally-occurring inhibitors exist, such angiostatin and endostatin. There are a number of drugs undergoing study in the treatment of proliferative synovitis, which capitalise on the correlation between angiogenesis inhibition and the reduction of signs and symptoms of RA. Paclitaxel and an anti-integrin alpha(V)beta3 antibody, LM-609, are currently in clinical trials. Other drugs that may inhibit angiogenesis in RA include TNP-470 (formerly called AGM-1470), PPI-2458, PTK-787, bevacizumab and thalidomide. Many of these drugs have shown promise for the treatment of oncologic disorders, and are now being evaluated for the treatment of proliferative synovitis.

Are synovial biopsies of diagnostic value?

Synovial tissue is readily accessible by closed needle or arthroscopic biopsy. These techniques provide adequate tissue for most diagnostic requirements. Examination of synovial tissue can assist in the diagnosis of some joint infections, and in several atypical or rare synovial disorders. Histological confirmation is not normally required for diagnosis of the common forms of inflammatory arthritis, including rheumatoid arthritis (RA). In patients with either established or early RA, immunohistological measures of inflammation in synovial tissue are associated with clinical measures of disease activity, may predict the clinical outcome, and change in response to treatment. Surrogate markers of disease activity and outcome that have been identified in synovial tissue include components of the cellular infiltrate, and several mediators of inflammation and matrix degradation. There is evidence that the very early introduction of disease-modifying therapy inhibits progressive structural damage maximally. Clinicians exploiting this 'window of opportunity' therefore require very early indicators of the diagnosis and outcome in patients who present with an undifferentiated inflammatory arthritis. Some immunohistological features have been described that distinguish patients who are likely to develop progressive RA and who might benefit most from early aggressive therapeutic intervention. In this regard, the inclusion of pharmacogenomic and proteomic techniques in the analysis of synovial tissue presents some exciting possibilities for future research.