Effect of spironolactone on endothelial dysfunction in rheumatoid arthritis

The endothelial mineralocorticoid receptor: Contributions to sex differences in cardiovascular disease

Cardiovascular disease remains the leading cause of death for both men and women. The observation that premenopausal women are protected from cardiovascular disease relative to age-matched men, and that this protection is lost with menopause, has led to extensive study of the role of sex steroid hormones in the pathogenesis of cardiovascular disease. However, the molecular basis for sex differences in cardiovascular disease is still not fully understood, limiting the ability to tailor therapies to male and female patients. Therefore, there is a growing need to investigate molecular pathways outside of traditional sex hormone signaling to fully understand sex differences in cardiovascular disease. Emerging evidence points to the mineralocorticoid receptor (MR), a steroid hormone receptor activated by the adrenal hormone aldosterone, as one such mediator of cardiovascular disease risk, potentially serving as a sex-dependent link between cardiovascular risk factors and disease. Enhanced activation of the MR by aldosterone is associated with increased risk of cardiovascular disease. Emerging evidence implicates the MR specifically within the endothelial cells lining the blood vessels in mediating some of the sex differences observed in cardiovascular pathology. This review summarizes the available clinical and preclinical literature concerning the role of the MR in the pathophysiology of endothelial dysfunction, hypertension, atherosclerosis, and heart failure, with a special emphasis on sex differences in the role of endothelial-specific MR in these pathologies. The available data regarding the molecular mechanisms by which endothelial-specific MR may contribute to sex differences in cardiovascular disease is also summarized. A paradigm emerges from synthesis of the literature in which endothelial-specific MR regulates vascular function in a sex-dependent manner in response to cardiovascular risk factors to contribute to disease. Limitations in this field include the relative paucity of women in clinical trials and, until recently, the nearly exclusive use of male animals in preclinical investigations. Enhanced understanding of the sex-specific roles of endothelial MR could lead to novel mechanistic insights underlying sex differences in cardiovascular disease incidence and outcomes and could identify additional therapeutic targets to effectively treat cardiovascular disease in men and women.

Effect of spironolactone for 1 yr on endothelial function and vascular inflammation biomarkers in renal transplant recipients

Kidney transplantation is associated with increased cardiovascular risk. Endothelial dysfunction and vascular inflammation contribute to negative outcome. In experimental models, mineralocorticoid receptor antagonists improved endothelial function and reduced inflammation. The present study tested the hypothesis that the mineralocorticoid receptor antagonist spironolactone improves endothelial function and reduces vascular inflammation in renal transplant patients. Eighty prevalent renal transplant patients from an ongoing, double-blind randomized placebo-controlled trial were included. Paired plasma samples before and after 1 yr of treatment (n = 39 in the spironolactone-treated group and 41 in the placebo-treated group) were used to determine markers of endothelial dysfunction (nitrite, nitrate, cGMP, arginine, citrulline, ornithine, asymmetric dimethylarginine, symmetric dimethylarginine, N^G-monomethyl-l-arginine, von Willebrand factor, tissue-type plasminogen activator antigen, and plasminogen activator inhibitor 1 antigen) and markers of inflammation (intercellular adhesion molecule, vascular adhesion molecule, high-sensitivity C-reactive protein, and serum amyloid protein A). The median time since the transplantation was 4.6 (0.12-22.3) yr in the spironolactone-treated group and 2.1 (0.17-13.9) yr in the placebo-treated group (P > 0.05). Spironolactone increased plasma aldosterone (P < 0.001) and K⁺ (P < 0.001). Blood pressure did not change significantly. No significant differences were detected between groups in any of the measured markers of endothelial dysfunction or inflammation except in the subgroup analysis of patients with diabetes, where spironolactone decreased nitrite compared with placebo. In this study, mineralocorticoid receptor antagonism did not improve biomarkers of endothelial dysfunction or vascular inflammation in prevalent renal transplant patients. Further studies are needed to evaluate the potential beneficial effect of early or late mineralocorticoid receptor antagonism on vascular outcomes in renal transplant patients.

Spironolactone (an adjuvant therapy) in rheumatoid arthritis: a case control study

OBJECTIVES

Disease-modifying anti-rheumatic drugs (DMARDs) are conventionally used in rheumatoid arthritis (RA). The role of spironolactone as add on therapy to DMARDs in RA patients was evaluated.

MATERIAL AND METHODS

A total of 100 patients with rheumatoid arthritis diagnosed as per 1987 criteria having evidence of active disease despite ongoing DMARD therapy were enrolled in this study. Patients were assigned randomly to two groups. Group I (n = 50) patients were treated with 50 mg/day of spironolactone along with their maintenance DMARD and NSAID therapy. Group II (n = 50) patients continued their maintenance DMARD therapy without spironolactone. Disease activity was assessed using the Disease Activity Score-28 (DAS28) and the Clinical Disease Activity Index (CDAI) in each patient of each group was evaluated monthly for the next three months.

RESULTS

All patients completed the study. Mean age of group I was 46.44 ±11.67 and of group II 44.52 ±11.82. DAS28 assessed in time according to the schedule was for group I 6.78 ±0.74, 5.34 ±0.74, 3.98 ±0.7, 3.00 ±0.75, while in group II it was 6.61 ±0.82, 5.49 ±0.90, 4.58 ±0.81, 3.55 ±0.93 at baseline, 4, 8, and 12 weeks respectively. CDAI in group I was 41.68 ±11.14, 24.36 ±8.13, 12.34 ±5.73, 6.42 ±4.4 and in group II 37.84 ±11.12, 24.54 ±9.4, 16.38 ±6.81, 9.62 ±6.1 at baseline, 4, 8, and 12 weeks respectively. Group I showed significant improvement in disease activity in the form of tender joint count (p = 0.001), swollen joint count (p = 0.023), patient global assessment (p = 0.001), physician global health (p = 0.001), DAS28 (p < 0.001) and CDAI (p = 0.001) but other parameters showed non-significant improvement compared to group II. No serious adverse events were observed in either group during the course of the study.

CONCLUSIONS

Spironolactone as an adjuvant therapy can improve the effect of conventional DMARD treatment of patients with RA.

Spironolactone

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Nitric Oxide: Link between Inflammation and Endothelial Dysfunction in Rheumatoid Arthritis

Nitric oxide (NO) plays an important role in inflammatory joint disease and endothelial function. Endothelial dysfunction has been attributed to a reduction in NO bioactivity in rheumatoid arthritis (RA). However, the relationship of NO with inflammation and endothelial dysfunction in RA has not yet been investigated. To investigate the relationship of nitrite with inflammation and endothelial dysfunction in RA. Total 28 patients satisfying 2010 Rheumatoid Arthritis Classification Criteria were recruited for the study. Serum nitrite estimation was performed by Griess reaction. Flow-mediated dilation (FMD) assessed using AngioDefender. Inflammatory disease activity measures included disease activity score of 28 joints (DAS28), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP). Proinflammatory cytokines (TNF-α, IL-6, and IL-1) measured using standard ELISA kits. Twenty-five healthy controls matched for age and sex were included for comparison. The serum nitrite level in patients with RA was markedly elevated as compared with controls ( p  < 0.05). FMD was significantly impaired in RA patients than controls ( p  < 0.05). DAS28 was significantly higher in RA patients ( p  < 0.05). Levels of ESR, CRP, TNF-α, IL-1, and IL-6 were significantly higher in RA patients than controls ( p  < 0.05). Significant positive correlation was observed between nitrite and CRP ( r  = 0.46, p  < 0.05), TNF-α ( r  = 0.53, p  < 0.05), and inverse correlation with FMD ( r =0.62, p  < 0.05). Inflammatory disease activity and endothelial dysfunction in RA are associated with increased concentration of proinflammatory cytokines and NO. Inflammatory triggered release of cytokines induced NO production that mediates endothelial dysfunction. These findings suggest a role for NO in inflammation-induced endothelial dysfunction in RA.

Rosuvastatin improves endothelial dysfunction in ankylosing spondylitis

Enhanced cardiovascular risk in ankylosing spondylitis (AS) provides a strong rationale for early therapeutical intervention. In view of the proven benefit of statins in atherosclerotic vascular disease, we aimed to investigate the effect of rosuvastatin on endothelial dysfunction (ED) and inflammatory disease activity in AS. In a single-blind, placebo-controlled, parallel study, 32 AS patients were randomized to receive 24 weeks of treatment with rosuvastatin (10 mg/day, n = 17) and placebo (n = 15) as an adjunct to existing stable antirheumatic drugs. Flow-mediated dilatation (FMD) was assessed by AngioDefender™ (Everest Genomic Ann Arbor, USA). Inflammatory measures (BASDAI, BASFI, CRP and ESR) and pro-inflammatory cytokines (tumour necrosis factor-alpha [TNF-α], interleukin-6 [IL-6] and interleukin-1 [IL-1]) were measured at baseline and after treatment. Lipids and adhesion molecules (intracellular adhesion molecule [ICAM-1] and vascular cell adhesion molecule [VCAM-1]) were estimated at baseline and after treatment. At baseline, inflammatory measures, pro inflammatory cytokines and adhesion molecules were elevated among both groups. After treatment with rosuvastatin, FMD improved significantly (p < 0.01). Levels of inflammatory measures, TNF-α, IL-6 and ICAM-1 decreased significantly (p < 0.01) after treatment with rosuvastatin. Rosuvastatin exerted positive effect on lipid spectrum. No significant change in the placebo group. Significant negative correlation was observed between FMD and IL-6, ICAM-1, CRP after treatment with rosuvastatin. First study to show that rosuvastatin improves inflammatory disease activity and ED in AS. Rosuvastatin lowers the proinflammatory cytokines, especially IL-6 and TNF-α, which downregulates adhesion molecules and CRP production which in turns improves ED. Improvement in ED in AS occurs through both cholesterol-independent and cholesterol-dependent pathways. Rosuvastatin can mediate modest but clinically apparent anti-inflammatory effects with modification of vascular risk factors in the context of high-grade autoimmune inflammation of AS.

Endothelial dysfunction in chronic inflammatory diseases

Chronic inflammatory diseases are associated with accelerated atherosclerosis and increased risk of cardiovascular diseases (CVD). As the pathogenesis of atherosclerosis is increasingly recognized as an inflammatory process, similarities between atherosclerosis and systemic inflammatory diseases such as rheumatoid arthritis, inflammatory bowel diseases, lupus, psoriasis, spondyloarthritis and others have become a topic of interest. Endothelial dysfunction represents a key step in the initiation and maintenance of atherosclerosis and may serve as a marker for future risk of cardiovascular events. Patients with chronic inflammatory diseases manifest endothelial dysfunction, often early in the course of the disease. Therefore, mechanisms linking systemic inflammatory diseases and atherosclerosis may be best understood at the level of the endothelium. Multiple factors, including circulating inflammatory cytokines, TNF-α (tumor necrosis factor-α), reactive oxygen species, oxidized LDL (low density lipoprotein), autoantibodies and traditional risk factors directly and indirectly activate endothelial cells, leading to impaired vascular relaxation, increased leukocyte adhesion, increased endothelial permeability and generation of a pro-thrombotic state. Pharmacologic agents directed against TNF-α-mediated inflammation may decrease the risk of endothelial dysfunction and cardiovascular disease in these patients. Understanding the precise mechanisms driving endothelial dysfunction in patients with systemic inflammatory diseases may help elucidate the pathogenesis of atherosclerosis in the general population.

The cardioprotective effects of mineralocorticoid receptor antagonists

Despite state-of-the-art reperfusion therapy, morbidity and mortality remain significant in patients with an acute myocardial infarction. Therefore, novel strategies to limit myocardial ischemia-reperfusion injury are urgently needed. Mineralocorticoid receptor (MR) antagonists are attractive candidates for this purpose, since several clinical trials in patients with heart failure have reported a survival benefit with MR antagonist treatment. MRs are expressed by several cells of the cardiovascular system, including cardiomyocytes, cardiac fibroblasts, vascular smooth muscle cells, and endothelial cells. Experiments in animal models of myocardial infarction have demonstrated that acute administration of MR antagonists, either before ischemia or immediately at the moment of coronary reperfusion, limits infarct size. This action appears to be independent of the presence of aldosterone and cortisol, which are the endogenous ligands for the MR. The cardioprotective effect is mediated by a nongenomic intracellular signaling pathway, including adenosine receptor stimulation, and activation of several components of the Reperfusion Injury Salvage Kinase (RISK) pathway. In addition to limiting infarct size, MR antagonists can improve scar healing when administered shortly after reperfusion and can reduce cardiac remodeling post myocardial infarction. Clinical trials are currently being performed studying whether early administration of MR antagonists can indeed improve prognosis in patients with an acute myocardial infarction, independent of the presence of heart failure.

A pilot study of the effect of spironolactone therapy on exercise capacity and endothelial dysfunction in pulmonary arterial hypertension: study protocol for a randomized controlled trial

BACKGROUND

Pulmonary arterial hypertension is a rare disorder associated with poor survival. Endothelial dysfunction plays a central role in the pathogenesis and progression of pulmonary arterial hypertension. Inflammation appears to drive this dysfunctional endothelial phenotype, propagating cycles of injury and repair in genetically susceptible patients with idiopathic and disease-associated pulmonary arterial hypertension. Therapy targeting pulmonary vascular inflammation to interrupt cycles of injury and repair and thereby delay or prevent right ventricular failure and death has not been tested. Spironolactone, a mineralocorticoid and androgen receptor antagonist, has been shown to improve endothelial function and reduce inflammation. Current management of patients with pulmonary arterial hypertension and symptoms of right heart failure includes use of mineralocorticoid receptor antagonists for their diuretic and natriuretic effects. We hypothesize that initiating spironolactone therapy at an earlier stage of disease in patients with pulmonary arterial hypertension could provide additional benefits through anti-inflammatory effects and improvements in pulmonary vascular function.

METHODS/DESIGN

Seventy patients with pulmonary arterial hypertension without clinical evidence of right ventricular failure will be enrolled in a randomized, double-blinded, placebo-controlled trial to investigate the effect of early treatment with spironolactone on exercise capacity, clinical worsening and vascular inflammation in vivo. Our primary endpoint is change in placebo-corrected 6-minute walk distance at 24 weeks and the incidence of clinical worsening in the spironolactone group compared to placebo. At a two-sided alpha level of 0.05, we will have at least 84% power to detect an effect size (group mean difference divided by standard deviation) of 0.9 for the difference in the change of 6-minute walk distance from baseline between the two groups. Secondary endpoints include the effect of spironolactone on the change in placebo-corrected maximal oxygen consumption; plasma markers of vascular inflammation and peripheral blood mononuclear cell gene expression profiles; sympathetic nervous system activation, renin-angiotensin-aldosterone system activation and sex hormone metabolism; and right ventricular structure and function using echocardiography and novel high-resolution magnetic resonance imaging-based techniques. Safety and tolerability of spironolactone will be assessed with periodic monitoring for hyperkalemia and renal insufficiency as well as the incidence of drug discontinuation for untoward effects.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01712620.

Levels of NT-proBNP, markers of low-grade inflammation, and endothelial dysfunction during spironolactone treatment in patients with diabetic kidney disease

Renin-angiotensin-aldosterone system (RAAS) blockade may reduce levels of biomarkers of chronic low-grade inflammation and endothelial dysfunction. We investigated the effect of spironolactone added to standard RAAS blockade on these biomarkers in an analysis of four original studies.

MATERIALS AND METHODS

The studies were double-blind, randomised, placebo-controlled studies in 46 type 1 and 23 type 2 diabetic patients with micro- or macroalbuminuria treated with angiotensin-converting enzyme inhibitor (ACE inhibitor) or angiotensin receptor blocker (ARB), and randomised to additional treatment with spironolactone 25 mg and placebo daily for 60 days.

OUTCOME MEASURES

Changes in inflammatory (hsCRP, s-ICAM, TNFα, IL-6, IL-8, Serum amyloid A, IL1β), endothelial dysfunction (sE-selectin, s-ICAM1, s-VCAM1, VWF, p-selectin, s-thrombomodulin) and NT-proBNP after each treatment period.

RESULTS

During spironolactone treatment, u-albumin excretion rate was reduced from 605 (411-890) to 433 (295-636) mg/24 h, as previously reported. Markers of inflammation and endothelial dysfunction did not change; only changes in NT-proBNP (reduced by 14%, p=0.05) and serum amyloid A (reduced by 62%, p=0.10) were borderline significant.

DISCUSSIONS

Our results indicate that the renoprotective effect of spironolactone when added to RAAS blockade is not mediated through anti-inflammatory pathways since markers of inflammation and endothelial dysfunction are not affected during treatment.

Intrathecal injection of spironolactone attenuates radicular pain by inhibition of spinal microglia activation in a rat model

Background

Microglia might play an important role in nociceptive processing and hyperalgesia by neuroinflammatory process. Mineralocorticoid receptor (MR) expressed on microglia might play a central role in the modulation of microglia activity. However the roles of microglia and MR in radicular pain were not well understood. This study sought to investigate whether selective MR antagonist spironolactone develop antinociceptive effects on radicular pain by inhibition neuroinflammation induced by spinal microglia activation.

Results

Radicular pain was produced by chronic compression of the dorsal root ganglia with SURGIFLO™. The expression of microglia, interleukin beta (IL-1β), interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α), NR1 subunit of the NMDA receptor (t-NR1), and NR1 subunit phosphorylated at Ser896 (p-NR1) were also markedly up-regulated. Intrathecal injection of spironolactone significantly attenuated pain behaviors as well as the expression of microglia, IL-1β, TNF-α, t-NR1, and p-NR1, whereas the production of IL-6 wasn’t affected.

Conclusion

These results suggest that intrathecal delivery spironolactone has therapeutic effects on radicular pain in rats. Decreasing the activation of glial cells, the production of proinflammatory cytokines and down-regulating the expression and phosphorylation of NMDA receptors in the spinal dorsal horn and dorsal root ganglia are the main mechanisms contributing to its beneficial effects.

Treatment with the arginase inhibitor Nw-hydroxy-nor-L-arginine restores endothelial function in rat adjuvant-induced arthritis

Introduction

Endothelial dysfunction (ED) participates to atherogenesis associated to rheumatoid arthritis. We recently reported increased arginase activity/expression in vessels from adjuvant-induced arthritis (AIA) rats. In the present study, we investigated the effects of a curative treatment with the arginase inhibitor N_w-hydroxy-nor-L-arginine (nor-NOHA) on vascular dysfunction in AIA rats.

Methods

AIA rats were treated with nor-NOHA (40 mg/kg/d, ip) for 21 days after the onset of arthritis. A group of untreated AIA rats and a group of healthy rats served as controls. ED was assessed by the vasodilatory effect of acetylcholine (Ach) on aortic rings. The role of superoxide anions, prostanoids, endothelium-derived hyperpolarizing factor (EDHF) and nitric oxide synthase (NOS) pathway was studied. Plasma levels of IL-6 and vascular endothelial growth factor (VEGF) were determined by ELISA kits. Arthritis severity was estimated by a clinical, radiological and histological analysis.

Results

Nor-NOHA treatment fully restored the aortic response to Ach to that of healthy controls. The results showed that this beneficial effect is mediated by an increase in NOS activity and EDHF and reduced superoxide anion production as well as a decrease in the activity of cyclooxygenase (COX)-2, thromboxane and prostacyclins synthases. In addition, nor-NOHA decreased IL-6 and VEGF plasma levels in AIA rats. By contrast, the treatment did not modify arthritis severity in AIA rats.

Conclusions

The treatment with an arginase inhibitor has a potent effect on ED in AIA independently of the severity of the disease. Our results suggest that this new pharmacological approach has the potential as a novel add-on therapy in the treatment of RA.

Vascular function and morphology in rheumatoid arthritis: a systematic review

OBJECTIVES

RA associates with significantly increased morbidity and mortality from cardiovascular disease (CVD). This may be due to complex interactions between traditional CVD risk factors, systemic rheumatoid inflammation and the vasculature. We reviewed the current literature to answer: (i) whether there is sufficient evidence that patients with RA have altered vascular function and morphology compared with normal controls; (ii) whether there is sufficient evidence to determine if such changes relate predominantly to systemic inflammation; and (iii) whether any changes of vascular function and morphology in RA can be modified with therapy.

METHODS

The MEDLINE database was searched to identify publications from 1974 to 1 November 2010 pertaining to vascular function and morphology in RA. The total number of articles included in the present review was 93. This included 57 cross-sectional studies, 27 longitudinal studies without randomization and 9 longitudinal studies with randomization.

RESULTS

Vascular function and morphology was impaired in RA relative to healthy controls. The majority of studies reported no associations between systemic inflammation and vascular function. Treatment with anti-inflammatory medication resulted in both transient and long-term improvements in the vasculature, but only a few studies reported associations between change in inflammation and change in vascular function and morphology.

CONCLUSION

The link between systemic inflammation and vascular function and morphology is not wholly supported by the available literature. Long-term studies examining specific predictors (including CVD risk factors) on the vasculature in RA are needed.

Inflammation and therapy for hypertension

It is currently accepted that hypertension, atherosclerosis, and diabetes are disorders with subtle or overt activation of inflammatory mediators. Therefore, it has become increasingly important to ascertain whether current antihypertensive drug families have proinflammatory or anti-inflammatory actions that modify the outcomes of their hemodynamic effects on blood pressure. We review the current state of knowledge about the effects of the major classes of available antihypertensive agents on inflammation and speculate on the possible contribution of these effects to observations in clinical trials. We suggest that a strategy of drug development specifically addressing inflammation in hypertension may provide increased benefit in terms of target organ damage, and we describe some examples of these promising developments.

Assessment of endothelial function as a marker of cardiovascular risk in patients with rheumatoid arthritis

The endothelium is a major regulator of cardiovascular function and maintains an atheroprotective role through several mechanisms, including vasodilatation, inhibition of platelet aggregation, having anticoagulant and profibrinolytic effects, and having an anti-inflammatory effect. Early changes in the normal functioning of the endothelium are key initiating factors in the development and progression of atherosclerosis. These changes are present well before the presentation of clinical symptoms. Thus, researchers have focused much attention on developing methods for reliable non-invasive testing of endothelial function to allow early detection and monitoring and progression of subclinical atherosclerosis. To date, there is a wide range of methods in use to assess endothelial function, each with its own advantages and limitations. Ideally, the tests should be non-invasive to allow repeated measurements and be applicable in normal healthy subjects and also in children. Given the wide range of regulatory functions of the endothelium, it is not surprising that there is no single measure of endothelial function that provides all the necessary information regarding vascular integrity in different vascular beds. Therefore, a combination of tests examining different components of the vascular system is more appropriate. Since patients with rheumatoid arthritis have increased mortality due to cardiovascular disease, assessment of endothelial function could prove to be useful tools in the identification and monitoring of cardiovascular risk. The purpose of this review is to give a brief overview of some of the commonly used techniques for assessment of endothelial function, and in particular on those that have been used in studies of patients with rheumatoid arthritis.

The role of endothelial function and its assessment in rheumatoid arthritis

Patients with rheumatoid arthritis (RA) have a reduced life expectancy when compared with the general population, largely attributable to cardiovascular disease. Factors that contribute to this increased cardiovascular risk include traditional risk factors, which account for only part of the excess, along with manifestations of the disease itself. RA is characterized by inflammation, which also is a key component in the development of atherosclerosis. Inflammation leads to the activation of endothelial cells, which, through an increase in the expression of leukocyte adhesion molecules, promotes a pro-atherosclerotic environment. Endothelial dysfunction is an early preclinical marker of atherosclerosis, and is commonly found in patients with RA. Several methods are available for the assessment of endothelial function, such as flow-mediated dilatation and laser Doppler flowmetry combined with iontophoresis, each with its own advantages and limitations. Studies have shown that endothelial dysfunction in RA is closely associated with inflammation, and therapeutic reduction of inflammation leads to improvements in endothelial function. As such, assessments of endothelial function could prove to be useful tools in the identification and monitoring of cardiovascular risk in patients with RA. Given the increase in cardiovascular mortality associated with RA, effective management must involve prevention of cardiovascular risk, in addition to control of disease activity and inflammation.

Endothelial dysfunction in ankylosing spondylitis improves after tumor necrosis factor-alpha blockade

Chronic inflammation in ankylosing spondylitis (AS) is associated with vascular endothelial dysfunction. Infliximab improves inflammatory disease activity in AS patients, but its effect on endothelial dysfunction has still not been tested in these patients. Twelve anti-TNF naive AS patients (mean age, 32.6 +/- 3.94 years; disease duration, 5.6 +/- 0.8 years) with high disease activity [Bath ankylosing spondylitis disease activity index (BASDAI score > 4)] despite treatment with stable doses of conventional disease modifying anti-rheumatic drugs (DMARDs) were investigated. Inflammatory disease activity [BASDAI and Bath ankylosing spondylitis functional index (BASFI) scores, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) levels], serum nitrite concentration, and endothelium-dependent and endothelium-independent vasodilation of the brachial artery were measured at baseline and 12 weeks of therapy after single intravenous infusion of infliximab (5 mg/kg). Previous DMARD(s) regimen remained unchanged throughout the study period. After treatment with infliximab, flow-mediated vasodilation improved from 9.81 +/- 1.70% to 26.93 +/- 2.34% (p < 0.001), whereas there was no significant change in endothelium-independent vasodilation with nitroglycerin and baseline diameter (13.65 +/- 2.10% versus 14.59 +/- 1.93%, p = 0.08, and 4.45 +/- 0.15 versus 4.46 +/- 0.15 mm, p = 0.3, respectively). Nitrite concentration reduced from 6.50 +/- 0.21 to 2.57 +/- 0.18 micromol/l (p < 0.001), ESR from 40.90 +/- 6.00 to 11.50 +/- 1.38 mm in the first hour (p < 0.001), and CRP level from 29.08 +/- 4.11 to 2.69 +/- 0.43 mg/dl (p < 0.001). BASDAI and BASFI scores were significantly reduced from 5.40 +/- 1.14 to 1.40 +/- 0.70 (p < 0.05) and 5.05 +/- 1.76 to 0.20 +/- 0.63 (p < 0.05), respectively. The study suggests that in ankylosing spondylitis, endothelial dysfunction is a part of the disease process and infliximab improves both endothelial dysfunction and inflammatory disease activity.