Novel mode of action of iloprost: in vitro down-regulation of endothelial cell adhesion molecules

Wilderness Medical Society Clinical Practice Guidelines for the Prevention and Treatment of Frostbite: 2024 Update

The Wilderness Medical Society convened an expert panel to develop a set of evidence-based guidelines for the prevention and treatment of frostbite. We present a review of pertinent pathophysiology. We then discuss primary and secondary prevention measures and therapeutic management. Recommendations are made regarding each treatment and its role in management. These recommendations are graded on the basis of the quality of supporting evidence and balance between the benefits and risks or burdens for each modality according to methodology stipulated by the American College of Chest Physicians. This is an updated version of the guidelines published in 2019.

Use of Inhaled Epoprostenol in Patients With COVID-19 Receiving Humidified, High-Flow Nasal Oxygen Is Associated With Progressive Respiratory Failure

BACKGROUND

The clinical benefit of using inhaled epoprostenol (iEpo) through a humidified high-flow nasal cannula (HHFNC) remains unknown for patients with COVID-19.

RESEARCH QUESTION

Can iEpo prevent respiratory deterioration for patients with positive SARS-CoV-2 findings receiving HHFNC?

STUDY DESIGN AND METHODS

This multicenter retrospective cohort analysis included patients aged 18 years or older with COVID-19 pneumonia who required HHFNC treatment. Patients who received iEpo were propensity score matched to patients who did not receive iEpo. The primary outcome was time to mechanical ventilation or death without mechanical ventilation and was assessed using Kaplan-Meier curves and Cox proportional hazard ratios. The effects of residual confounding were assessed using a multilevel analysis, and a secondary analysis adjusted for outcome propensity also was performed in a multivariable model that included the entire (unmatched) patient cohort.

RESULTS

Among 954 patients with positive SARS-CoV-2 findings receiving HHFNC therapy, 133 patients (13.9%) received iEpo. After propensity score matching, the median number of days until the composite outcome was similar between treatment groups (iEpo: 5.0 days [interquartile range, 2.0-10.0 days] vs no-iEpo: 6.5 days [interquartile range, 2.0-11.0 days]; P = .26), but patients who received iEpo were more likely to meet the composite outcome in the propensity score-matched, multilevel, and multivariable unmatched analyses (hazard ratio, 2.08 [95% CI, 1.73-2.50]; OR, 4.72 [95% CI, 3.01-7.41]; and OR, 1.35 [95% CI, 1.23-1.49]; respectively).

INTERPRETATION

In patients with COVID-19 receiving HHFNC therapy, use of iEpo was associated with the need for invasive mechanical ventilation.

Paracrine Role of the Endothelium in Metabolic Homeostasis in Health and Nutrient Excess

The vascular endothelium traditionally viewed as a simple physical barrier between the circulation and tissue is now well-established as a key organ mediating whole organism homeostasis by release of a portfolio of anti-inflammatory and pro-inflammatory vasoactive molecules. Healthy endothelium releases anti-inflammatory signaling molecules such as nitric oxide and prostacyclin; in contrast, diseased endothelium secretes pro-inflammatory signals such as reactive oxygen species, endothelin-1 and tumor necrosis factor-alpha (TNFα). Endothelial dysfunction, which has now been identified as a hallmark of different components of the cardiometabolic syndrome including obesity, type 2 diabetes and hypertension, initiates and drives the progression of tissue damage in these disorders. Recently it has become apparent that, in addition to vasoactive molecules, the vascular endothelium has the potential to secrete a diverse range of small molecules and proteins mediating metabolic processes in adipose tissue (AT), liver, skeletal muscle and the pancreas. AT plays a pivotal role in orchestrating whole-body energy homeostasis and AT dysfunction, characterized by local and systemic inflammation, is central to the metabolic complications of obesity. Thus, understanding and targeting the crosstalk between the endothelium and AT may generate novel therapeutic opportunities for the cardiometabolic syndrome. Here, we provide an overview of the role of the endothelial secretome in controlling the function of AT. The endothelial-derived metabolic regulatory factors are grouped and discussed based on their physical properties and their downstream signaling effects. In addition, we focus on the therapeutic potential of these regulatory factors in treating cardiometabolic syndrome, and discuss areas of future study of potential translatable and clinical significance. The vascular endothelium is emerging as an important paracrine/endocrine organ that secretes regulatory factors in response to nutritional and environmental cues. Endothelial dysfunction may result in imbalanced secretion of these regulatory factors and contribute to the progression of AT and whole body metabolic dysfunction. As the vascular endothelium is the first responder to local nutritional changes and adipocyte-derived signals, future work elucidating the changes in the endothelial secretome is crucial to improve our understanding of the pathophysiology of cardiometabolic disease, and in aiding our development of new therapeutic strategies to treat and prevent cardiometabolic syndrome.

Interleukin-22 and connective tissue diseases: emerging role in pathogenesis and therapy

Interleukin-22 (IL-22), a member of the IL-10 family of cytokines, is produced by a number of immune cells involved in the immune microenvironment of the body. IL-22 plays its pivotal roles by binding to the IL-22 receptor complex (IL-22R) and subsequently activating the IL-22R downstream signalling pathway. It has recently been reported that IL-22 also contributes to the pathogenesis of many connective tissue diseases (CTDs). In this review, we will discuss the role of IL-22 in several CTDs, such as system lupus erythematosus, rheumatoid arthritis, Sjögren’s syndrome, systemic sclerosis and dermatomyositis, suggesting that IL-22 may be a potential therapeutic target in CTDs.

Wilderness Medical Society Clinical Practice Guidelines for the Prevention and Treatment of Frostbite: 2019 Update

The Wilderness Medical Society convened an expert panel to develop a set of evidence-based guidelines for prevention and treatment of frostbite. We present a review of pertinent pathophysiology. We then discuss primary and secondary prevention measures and therapeutic management. Recommendations are made regarding each treatment and its role in management. These recommendations are graded on the basis of the quality of supporting evidence and balance between the benefits and risks or burdens for each modality according to methodology stipulated by the American College of Chest Physicians. This is an updated version of the guidelines published in 2014.

Treatment with intranasal iloprost reduces disease manifestations in a murine model of previously established COPD

Pulmonary endothelial prostacyclin appears to be involved in the pathogenesis of chronic obstructive pulmonary disease (COPD). The effect of treatment with a prostacyclin analog in animal models of previously established COPD is unknown. We evaluated the short- and long-term effect of iloprost on inflammation and airway hyperresponsiveness (AHR) in a murine model of COPD. Nineteen mice were exposed to LPS/elastase, followed by either three doses of intranasal iloprost or saline. In the long-term treatment experiment, 18 mice were exposed to LPS/elastase and then received 6 wk of iloprost or were left untreated as controls. In the short-term experiment, iloprost did not change AHR but significantly reduced serum IL-5 and IFN-γ. Long-term treatment with iloprost for both 2 and 6 wk significantly improved AHR. After 6 wk of iloprost, there was a reduction in bronchoalveolar lavage (BALF) neutrophils, serum IL-1β (30.0 ± 9.2 vs. 64.8 ± 7.4 pg/ml, P = 0.045), IL-2 (36.5 ± 10.6 vs. 83.8 ± 0.4 pg/ml, P = 0.01), IL-10 (75.7 ± 9.3 vs. 96.5 ± 3.5 pg/ml, P = 0.02), and nitrite (15.1 ± 5.4 vs. 30.5 ± 10.7 μmol, P = 0.01). Smooth muscle actin (SMA) in the lung homogenate was also significantly reduced after iloprost treatment (P = 0.02), and SMA thickness was reduced in the small and medium blood vessels after iloprost (P < 0.001). In summary, short- and long-term treatment with intranasal iloprost significantly reduced systemic inflammation in an LPS/elastase COPD model. Long-term iloprost treatment also reduced AHR, serum nitrite, SMA, and BALF neutrophilia. These data encourage future investigations of prostanoid therapy as a novel treatment for COPD patients.

Des-aspartate-angiotensin I, a novel angiotensin AT(1) receptor drug

The review describes DAA-I (des-aspartate-angiotensin-I) as a prototype of a novel class of drugs that acts as agonists on the angiotensin AT1 receptor or ARAs (angiotensin receptor agonists). DAA-I is a component of the renin angiotensin system. Earlier studies showed that it was rapidly metabolized to angiotensin III. However, when administered at doses below the Km of enzymes, DAA-I produces specific actions that antagonize the deleterious actions of angiotensin II. DAA-I exerts protective actions in animal models of eight human pathologies in which angiotensin II is implicated. The pathologies include cardiac hypertrophy, neointima growth and cardiovascular hypertrophy, myocardial-ischemia reperfusion injury, hyperglycemia and insulin resistance, chemical induced inflammation, and exercise-induced skeletal muscle inflammation. Binding of DAA-I to the angiotensin AT1 receptors releases prostaglandins, which could either function as autocrines/paracrines or second messengers and attenuate the deleterious actions of angiotensin II. It is possible that in in vivo DAA-I functions as a physiological antagonist to angiotensin II, and exogenous DAA-I is a novel class of angiotensin receptor drug that could rival the angiotensin receptor blockers.

Vascular involvement in systemic sclerosis (scleroderma)

Systemic sclerosis (SSc) is an acquired multiorgan connective tissue disease with variable mortality and morbidity dictated by clinical subset type. The etiology of the basic disease and pathogenesis of the systemic autoimmunity, fibrosis, and fibroproliferative vasculopathy are unknown and debated. In this review, the spectrum of vascular abnormalities and the options currently available to treat the vascular manifestations of SSc are discussed. Also discussed is how the hallmark pathologies (ie, how autoimmunity, vasculopathy, and fibrosis of the disease) might be effected and interconnected with modulatory input from lysophospholipids, sphingosine 1-phosphate, and lysophosphatidic acid.

Prostacyclin: an inflammatory paradox

Prostacyclin (PGI₂) is a member of the prostaglandin family of bioactive lipids. Its best-characterized role is in the cardiovascular system, where it is released by vascular endothelial cells, serving as a potent vasodilator and inhibitor of platelet aggregation. In recent years, prostacyclin (PGI₂) has also been shown to promote differentiation and inhibit proliferation in vascular smooth muscle cells. In addition to these well-described homeostatic roles within the cardiovascular system, prostacyclin (PGI₂) also plays an important role as an inflammatory mediator. In this review, we focus on the contribution of prostacyclin (PGI₂) as both a pathophysiological mediator and therapeutic agent in three major inflammatory-mediated disease processes, namely rheumatoid arthritis, where it promotes disease progression (“pro-inflammatory”), along with pulmonary vascular disease and atherosclerosis, where it inhibits disease progression (“anti-inflammatory”). The emerging role of prostacyclin (PGI₂) in this context provides new opportunities for understanding the complex molecular basis for inflammatory-related diseases, and insights into the development of current and future anti-inflammatory treatments.

Large leg ulcers due to autoimmune diseases

Background

Large leg ulcers (LLU) may complicate autoimmune diseases. They pose a therapeutic challenge and are often resistant to treatment. To report three cases of autoimmune diseases complicated with LLU.

Case Report

Case 1. A 55-year old woman presented with long-standing painful LLU due to mixed connective tissue disease (MCTD). Biopsy from the ulcer edge showed small vessel vasculitis. IV methylprednisolone (MethP) 1 G/day, prednisolone (PR) 1mg/kg, monthly IV cyclophosphamide (CYC), cyclosporine (CyA) 100mg/day, IVIG 125G, ciprofloxacin+IV Iloprost+enoxaparin+aspirin (AAVAA), hyperbaric oxygen therapy (HO), maggot debridement and autologous skin transplantation were performed and the LLU healed. Case 2. A 45-year old women with MCTD developed multiple LLU’s with non-specific inflammation by biopsy. MethP, PR, hydroxychloroquine (HCQ), azathioprine (AZA), CYC, IVIG, AAVAA failed. Treatment for underlying the LLU tibial osteomyelitis and addition of CyA was followed by the LLU healing. Case 3. A 20-year-old man with history of polyarteritis nodosa (PAN) developed painful LLU’s due to small vessel vasculitis (biopsy). MethP, PR 1 mg/kg, CYC, CyA 100 mg/d, AAVAA failed. MRSA sepsis and relapse of systemic PAN developed. IV vancomycin, followed by ciprofloxacin, monthly IVIG (150 g/for 5 days) and infliximab (5 mg/kg) were instituted and the LLU’s healed.

Conclusions

LLU are extremely resistant to therapy. Combined use of multiple medications and services are needed for healing of LLU due to autoimmune diseases.

Pulmonary arterial hypertension in systemic sclerosis

Pulmonary arterial hypertension (PAH) in systemic sclerosis (SSc) is a complex clinical situation resulting from restricted flow through the pulmonary arterial circulation ending in increased pulmonary vascular resistance and right heart failure. PAH is a common and life-threatening complication in connective tissue diseases, specifically in SSc if not treated rapidly and adequately. Based on the emerging knowledge in SSc epidemiology by large scale patient cohorts such as EUSTAR, of PAH pathophysiology and advances in cardiopulmonary diagnostic techniques, several novel treatment approaches have been examined and have proceeded to licensing and daily use in the clinical practice. Amongst them are different endothelin receptor antagonists and PDE-5 inhibitors, but several other ideas are being currently pursued to improve the long-term outcome of the affected patients.

Matrix-specific protein kinase A signaling regulates p21-activated kinase activation by flow in endothelial cells

RATIONALE

Atherosclerosis is initiated by blood flow patterns that activate inflammatory pathways in endothelial cells. Activation of inflammatory signaling by fluid shear stress is highly dependent on the composition of the subendothelial extracellular matrix. The basement membrane proteins laminin and collagen found in normal vessels suppress flow-induced p21 activated kinase (PAK) and nuclear factor (NF)-kappaB activation. By contrast, the provisional matrix proteins fibronectin and fibrinogen found in wounded or inflamed vessels support flow-induced PAK and NF-kappaB activation. PAK mediates both flow-induced permeability and matrix-specific activation of NF-kappaB.

OBJECTIVE

To elucidate the mechanisms regulating matrix-specific PAK activation.

METHODS AND RESULTS

We now show that matrix composition does not affect the upstream pathway by which flow activates PAK (integrin activation, Rac). Instead, basement membrane proteins enhance flow-induced protein kinase (PK)A activation, which suppresses PAK. Inhibiting PKA restored flow-induced PAK and NF-kappaB activation in cells on basement membrane proteins, whereas stimulating PKA inhibited flow-induced activation of inflammatory signaling in cells on fibronectin. PKA suppressed inflammatory signaling through PAK inhibition. Activating PKA by injection of the prostacyclin analog iloprost reduced PAK activation and inflammatory gene expression at sites of disturbed flow in vivo, whereas inhibiting PKA by PKA inhibitor (PKI) injection enhanced PAK activation and inflammatory gene expression. Inhibiting PAK prevented the enhancement of inflammatory gene expression by PKI.

CONCLUSIONS

Basement membrane proteins inhibit inflammatory signaling in endothelial cells via PKA-dependent inhibition of PAK.

Complex regulation and function of the inflammatory smooth muscle cell phenotype in atherosclerosis

Vascular smooth muscle cell (SMC) phenotypic modulation plays a key role in atherosclerosis and is classically defined as a switch from a 'contractile' phenotype to a 'synthetic' phenotype, whereby genes that define the contractile SMC phenotype are suppressed and proliferation and/or migratory mechanisms are induced. There is also evidence that SMCs may take on a 'proinflammatory' phenotype, whereby SMCs secrete cytokines and express cell adhesion molecules, e.g. IL-8, IL-6, and VCAM-1, respectively, which may functionally regulate monocyte and macrophage adhesion and other processes during atherosclerosis. Factors that drive the inflammatory phenotype are not limited to cytokines but also include hemodynamic forces imposed on the blood vessel wall and intimate interaction of endothelial cells with SMCs, as well as changes in matrix composition in the vessel wall. However, it is critical to recognize that our understanding of the complex interaction of these multiple signal inputs has only recently begun to shed light on mechanisms that regulate the inflammatory SMC phenotype, primarily through models that attempt to recreate this environment ex vivo. The goal of this review is to summarize our current knowledge in this area and identify some of the key unresolved challenges and questions requiring further study.

The human prostacyclin receptor from structure function to disease

Thirty years have passed since Vane and colleagues first described a substance, prostanoid X, from microsomal fractions (later called prostacyclin) that relaxed rather than contracted mesenteric arteries. The critical role of prostacyclin in many pathophysiological conditions, such as atherothrombosis, has only recently become appreciated (through receptor knockout mice studies, selective cyclooxygenase-2 inhibition clinical trials, and the discovery of dysfunctional prostacyclin receptor genetic variants). Additionally, important roles in such diverse areas as pain and inflammation, and parturition are being uncovered. Prostacyclin-based therapies, currently used for pulmonary hypertension, are accordingly emerging as possible treatments for such diseases, fueling interests in structure function studies for the receptor and signal transduction pathways in native cells. The coming decade is likely to yield many further exciting advances.

Capillaroscopic skin ulcer risk index: a new prognostic tool for digital skin ulcer development in systemic sclerosis patients

OBJECTIVE

Digital ulcerations are one of the most frequent manifestations of microangiopathy in patients with systemic sclerosis (SSc; scleroderma). The early detection of SSc patients who are at high risk to develop digital ulcers could allow a preventive treatment of these complications with reduction of morbidity and social costs. The aim of our study was to develop a capillaroscopic skin ulcer risk index (CSURI) that can predict the onset of new digital ulcers by using nailfold videocapillaroscopy (NVC) in patients with SSc.

METHODS

We performed NVC in 120 consecutive unselected patients with SSc (13 men, 107 women, mean +/- SD age 56.1 +/- 13.4 years, mean +/- SD SSc duration 44.7 +/- 60.7 months) to assess the total number of capillaries in the distal row (N), maximum loop diameter (D), number of megacapillaries (M), and the M:N ratio.

RESULTS

Within 3 months since NVC examination, 35 of 120 patients experienced digital ulcers. A significant association between ischemic lesions and the M:N ratio, N, and D was observed; the combination of these parameters allowed us to develop the CSURI, which is characterized by the formula D x M:N(2). A receiver operating characteristic curve analysis showed an area under the curve of 0.926 for ulcer appearance, with specificity and sensitivity of 85.9% and 94.3%, respectively, at the cutoff value of 2.94. Interestingly, 33 of 35 patients with new skin ulcers had a CSURI >2.94, but only 2 of 35 had a CSURI < or =2.94.

CONCLUSION

The proposed CSURI may represent a novel tool with the ability to predict the development of digital ulcers in patients with scleroderma.

Mechanisms of drug combinations: interaction and network perspectives

Understanding the molecular mechanisms underlying synergistic, potentiative and antagonistic effects of drug combinations could facilitate the discovery of novel efficacious combinations and multi-targeted agents. In this article, we describe an extensive investigation of the published literature on drug combinations for which the combination effect has been evaluated by rigorous analysis methods and for which relevant molecular interaction profiles of the drugs involved are available. Analysis of the 117 drug combinations identified reveals general and specific modes of action, and highlights the potential value of molecular interaction profiles in the discovery of novel multicomponent therapies.

Prevalence, serological features, response to treatment and outcome of critical peripheral ischaemia in a cohort of lupus patients

OBJECTIVE

This study addresses the issue of risk factors and management of critical peripheral ischaemia (CPI) and gangrene in SLE and proposes rituximab as a novel therapy.

METHOD

We conducted a retrospective study of 485 patients with SLE attending a UK tertiary referral centre, followed up over 27 yrs. Demographics, clinical features, serological features, treatment and outcome data were assessed.

RESULTS

Seven out of 485 patients (1.4%) had evidence of gangrene or CPI with onset at any stage of SLE disease from presenting feature to 27 yrs after SLE onset, aPL and LAC were over-represented in the CPI patients. All had active SLE at the time of CPI. All seven were treated with intravenous (IV) epoprostenol infusion and aPL-positive patients were anti-coagulated. One patient failed to respond to this treatment and to IV calcitonin gene-related peptide but responded to B-cell depletion therapy using rituximab. Five out of the seven patients suffered digit loss with auto-amputation.

CONCLUSION

CPI is a rare but potentially devastating complication of SLE associated with aPL, LAC and active SLE. B-cell depletion therapy with rituximab may be an option in severe ischaemia not improving with IV epoprostenol.

Effects of Beraprost Sodium, An Oral Prostaglandin I2 Analog, on Hemostatic Factors and Inflammation in Chronic Peritoneal Dialysis Patients

Beraprost sodium, an orally active prostaglandin I2 analog with vasodilatory, cytoprotective, antiplatelet, antithrombotic, and anti-inflammatory effects, 120 μg daily for 8 weeks, decreased plasma D-dimer, a marker of intravascular coagulation, and von Willebrand factor, a marker for endothelial injury, in 100 chronic peritoneal dialysis patients. Total cholesterol, triglycerides, high-density lipoprotein, apolipoprotein A1, apolipoprotein B, albumin, prealbumin, fibrinogen, troponin-T, and high-sensitivity C-reactive protein levels were not changed. Three patients complained of headache and 1 patient experienced facial flushing; however, no serious adverse effects were observed. These results suggest that beraprost sodium is effective in partially reversing the thrombogenic coagulation profile and endothelial injury in chronic peritoneal dialysis patients.

Iloprost infusion does not reduce oxidative stress in systemic sclerosis

Systemic sclerosis is a connective tissue disease in which oxidative stress represents an important player among the complex pathogenetic mechanisms of the disease. Iloprost, an analogue of natural prostacyclin, is used in systemic sclerosis for the treatment of severe Raynaud's phenomenon and ischemic ulcers. There is a clear evidence that iloprost attenuates oxidative damage induced by ischemia-reperfusion phenomena. The aim of this study is to evaluate the effect of iloprost on oxidative status in ten patients with systemic sclerosis by measuring urinary levels of 8-isoprostaglandin-F(2alpha), a member of F(2)-isoprostanes. We found that systemic sclerosis patients cyclically treated with iloprost showed increased urinary level of 8-isoprostaglandin-F(2alpha )in comparison with healthy subjects; urinary 8-isoprostaglandin-F(2alpha) did not diminish soon after the iloprost infusion as well as 3, 15 and 30 days after the drug administration. Unlike experimental studies, in vivo the strong vasodilator effect of iloprost infusion did not reduce oxidative status.

[Evidence-based therapy of Raynaud's syndrome]

Raynaud's syndrome has a prevalence of 3-5% in the general population. Despite its high frequency, the majority of available therapies have not been validated in randomized controlled trials. Effective therapies with a high level of evidence include the calcium channel blocker nifedipine. As analyzed by meta-analyses, nifedipine showed improvement of the peripheral circulation, as well as reduction of both the intensity and frequency of attacks in patients with primary and secondary Raynaud's syndrome as compared to placebo. Similar results in a metaanalysis were obtained for intravenous infusions of iloprost in patients with secondary Raynaud's phenomenon associated with systemic sclerosis. In addition, intravenous infusions of iloprost improved healing of fingertip ulcers in patients with systemic sclerosis. Therapies with significant effects in single randomized controlled trials include angiotensin II-receptor type 1 antagonists (losartan), the calcium channel blockers felodipine und amlodipine, serotonin-reuptake-inhibitors (fluoxetine) und phosphodiesterase-V-inhibitors (sildenafil, vardenafil). However, the results for these promising substances have to be confirmed in long-term trials with larger patient numbers.

Prostacyclin in sepsis: A systematic review

According to current literature, infective processes greatly modify both vascular hemodynamics and anti-oxidant properties of affected tissues, causing a change in homeostasis that regulates the correct functioning of all cells responsible for the physiological and metabolic balance of various organs. As a consequence, the response to the infection that has caused the change is also likely to be weaker and, in the case of septic shock, ineffective. In this review, we will take into consideration these mechanisms and then focus on a group of vasodilator drugs (prostacyclin and its analogs) which, though have been used for over 20 years mainly to treat obstructive vascular diseases, have such hemodynamic and anti-inflammatory properties which prevent homeostatic changes. It is obvious that prostacyclin does not definitively have anti-infective characteristics; however, in association with anti-infective drugs (antibiotics, etc.), the effectiveness of the latter appears improved, at least in some circumstances. Similarly, the fact that prostacyclin and its analogs have a cytoprotective effect on the liver and reduce the ischemia-reperfusion damage following liver transplant is not a novelty and evidence that they improve hepatic hemodynamics suggests their use in those pathologies characterized by possible reduced perfusion or ascertained ischemia of the liver.

Does cyclically iloprost infusion prevent severe isolated pulmonary hypertension in systemic sclerosis? Preliminary results

The objective of this study was to present our clinical experience about scleroderma-related pulmonary hypertension in the patients treated with intermittent iloprost infusions. Eighty-one patients affected by systemic sclerosis (12 men, 69 women; 30 with diffuse pattern and 51 with limited pattern; mean age 55.1 years; mean duration of disease 105.3 months) have been treated with cyclic iloprost infusions for at least 15 months (range 15-126 months). During the last 4 months all patients underwent Doppler echocardiography in order to estimate the value of systolic pulmonary artery pressure. In 14 subjects (17.2%) systolic pulmonary artery pressure was = or > 35 mmHg. Four patients presented high systolic pulmonary artery pressure associated with pulmonary fibrosis (mean value 40.5 +/- 4.5 mmHg). Ten women (one with diffuse pattern of disease and nine with limited form) showed isolated high systolic pulmonary artery pressure; one of these patients underwent right heart catheterization which resulted normal. The remaining nine patients (mean age of 67.1 years; age at the onset of scleroderma 52.2 years) showed estimated systolic pulmonary artery pressure values between 35 and 50 mmHg. Among these patients affected by isolated pulmonary hypertension only one has been receiving bosentan in association with iloprost infusions. None of our scleroderma patients treated with cyclic iloprost infusions developed severe isolated pulmonary hypertension. In systemic sclerosis the multiple effects of iloprost on endothelium, platelets and cytokine network may counteract the vasospastic profile of lung microvasculature in pulmonary arterial hypertension and the consequent vascular wall remodelling, thus preventing the development of severe illness.

Evaluation of finger skin temperature in scleroderma patients cyclically treated with iloprost

OBJECTIVES

To evaluate by computerized digital thermometry (CDT) the effect of cyclic iloprost infusions on finger skin temperature (FST) in scleroderma patients.

METHODS

Twenty-two scleroderma outpatients (one man, 21 women, mean age 54.2 years) underwent three computerized digital thermometries, the first one 3 days before a 5-day cycle of iloprost infusion, the second the day of the fifth infusion soon after the end of the therapy and the third 1 month after. FST was evaluated under basal conditions, immediately after a cold test and after an 18 min recovery period. For comparison CDT was performed in 10 sex and age matched control subjects.

RESULTS

FST was lower in scleroderma patients before iloprost infusion than in the control group either after cold test either at the end of the recovery period while no difference was found before the cold test. Soon after iloprost infusion and 1 month later the FST at the end of the recovery period increased from the pre-treatment value of 27.8 +/- 5.3 to 30.4 +/- 3.5 degrees C and to 30.0 +/- 4.5 degrees C, respectively (P < 0.05 for both values). No substantial differences were found concerning FST before and at the end of the cold test.

CONCLUSION

Iloprost administration for 5 days allows to normalize the FST value after cold exposition not only immediately after the infusions but even at 1 month distance from the therapy. Despite its short half-life the effect of the drug on endothelium is protracted.

[Treatment of therapy-resistant acral ulcers with iloprost]

Patients with systemic sclerosis (SSc) develop often acral ulcers which are resistant to therapy and may result in gangrene and amputation. We investigated the effects of iloprost infusion on the acral ulcers and necrosis in patients with five patients with SSc and one with mixed connective tissue disease who had been previously treated with various modalities without improvement. All patients had Raynaud phenomenon, acral ulcers and necrosis. Iloprost 25 microg per day was administered intravenously daily over six hours for ten consecutive days. Eight weeks later all patients were treated with a second iloprost therapy cycle for five days. Two patients with severe ulceration received a third cycle until remission occurred. In all cases acral ulcers healed completely and no patient relapsed during an observation period of 6 months.

Pulmonary arterial hypertension in mixed connective tissue disease: successful treatment with Iloprost

This paper describes a 61-year-old woman who presented with mixed connective tissue disease, which was complicated by the development of pulmonary arterial hypertension (PAH). Her condition worsened rapidly, with development of haemopthysis, tachypnoe and cardiac arrest. Doppler echocardiography showed a high systolic pulmonary arterial pressure (98 mmHg), confirmed by the right heart catheterization. Vasculopathy of the pulmonary artery vessels was detected following open lung biopsy. No pulmonary embolism was found. Because of suspicion of flare of her underlying disease, which leads to PAH, immunosuppressive treatment was started with high doses of corticosteroid and cyclophosphamide, in combination with the prostacyclin analogue, Iloprost, and low molecular weight heparin. The therapy resulted in slow recovery over 6 weeks, with control echocardiography showing normalization of the high pulmonary pressure, and the patient being capable of returning to everyday activities.

The impact of eicosanoids on the crosstalk between innate and adaptive immunity: the key roles of dendritic cells

The innate immune response is essentially the first line of defense against an invading pathogen. Through specialized receptors, known as pattern recognition receptors, especially Toll-like receptors, specialized cells of myeloid origin, including macrophages and dendritic cells (DCs) are able to phagocytose microorganisms and induce an innate inflammatory response. Although B and T lymphocytes recognize tissue antigens with high specificity, they are unable to initiate immune responses. The decision to activate an appropriate immune response is made by unique DC, the most professional antigen-presenting cells (APCs) which control the responses of several types of lymphocytes and play central role in the transition between innate and adaptive immunity. Increased secretion of inflammatory endogenous mediators such as cytokines and arachidonic acid-derived lipid mediators, also termed eicosanoids, can activate APC, particularly DC, which in turn induce an adaptive immune response. There is an increasing evidence that eicosanoids play an important role in connecting innate and adaptive immunity by acting on cells of both systems. Prostanoids, a major class of eicosanoids, have a great impact on inflammatory and immune responses. PGE(2) is one of the best known and most well-characterized prostanoids in terms of immunomodulation. Although cytokines are known as key regulators of immunity, eicosanoids, including PGE(2), PGD(2), LTB(4), and LTC(4), may also affect cells of immune system by modulating cytokine release, cell differentiation, survival, migration, antigen presentation, and apoptosis. By acting on various aspects of immune and inflammatory reactions, these lipid mediators emerge as key regulators of the crosstalk between innate and adaptive immunity.

Decrease in circulating endothelial cell adhesion molecule and thrombomodulin levels during oral iloprost treatment in rheumatoid arthritis patients: preliminary results

OBJECTIVE

Rheumatoid arthritis is a chronic inflammatory autoimmune disease with proinflammatory cytokines involved in its pathogenesis. Recently in vitro as well as in vivo studies have shown that iloprost, a stable prostacyclin analogue, can reduce the release of these cytokines. This study was performed to further investigate the anti-inflammatory effects of iloprost by determining plasma adhesion molecules as markers of endothelial cell activation, and plasma thrombomodulin as a parameter of endothelial cell injury in patients with rheumatoid arthritis receiving oral iloprost therapy.

METHODS

Plasma thrombomodulin levels and the values of the plasma adhesion molecules VCAM-1 (vascular cell adhesion molecule 1), E-selectin (CD62E), and ICAM-1 (intercellular adhesion molecule 1, CD 54) were measured by ELISA during a 7-day period of treatment with orally-administered iloprost in 14 patients with active rheumatoid arthritis. Finally, the same parameters were determined at the end of the observation period (1 week after the end of therapy). In addition, the disease activity was measured using the DAS (disease activity score) as well as the patients' self-assessed pain severity, and correlated with the changes of plasma adhesion molecule and thrombomodulin levels.

RESULTS

The plasma levels of all three adhesion molecules as well as of thrombomodulin significantly decreased under therapy with oral iloprost. After 1 week (day 7 of therapy), the mean percent changes from day 0 were -20.1% for VCAM-1 (p = 0.008), -21.2 for ICAM-1 (p = 0.003), -24.6% for E-selectin (p = 0.001), and -21.7% for thrombomodulin (p = 0.003). This decrease lasted up to 1 week after the end of therapy in the case of VCAM-1 (p = 0.023) and ICAM-1 (p = 0.001). Further analysis of the results revealed additional significant correlations between different parameters of clinical disease activity, thrombomodulin and adhesion molecules.

CONCLUSION

This study showed hints towards clinical effects in patients with rheumatoid arthritis receiving oral iloprost therapy. Pathophysiologically, the decrease of adhesion molecules points at an immunomodulating effect of iloprost. The observed thrombomodulin-lowering effect of iloprost may indicate stabilisation of endothelial cell function by diminishing endothelial cell injury.

Pharmacology and signaling of prostaglandin receptors: multiple roles in inflammation and immune modulation

Prostaglandins are lipid-derived autacoids that modulate many physiological systems including the CNS, cardiovascular, gastrointestinal, genitourinary, endocrine, respiratory, and immune systems. In addition, prostaglandins have been implicated in a broad array of diseases including cancer, inflammation, cardiovascular disease, and hypertension. Prostaglandins exert their effects by activating rhodopsin-like seven transmembrane spanning G protein-coupled receptors (GPCRs). The prostanoid receptor subfamily is comprised of eight members (DP, EP1-4, FP, IP, and TP), and recently, a ninth prostaglandin receptor was identified-the chemoattractant receptor homologous molecule expressed on Th2 cells (CRTH2). The precise roles prostaglandin receptors play in physiologic and pathologic settings are determined by multiple factors including cellular context, receptor expression profile, ligand affinity, and differential coupling to signal transduction pathways. This complexity is highlighted by the diverse and often opposing effects of prostaglandins within the immune system. In certain settings, prostaglandins function as pro-inflammatory mediators, but in others, they appear to have anti-inflammatory properties. In this review, we will discuss the pharmacology and signaling of the nine known prostaglandin GPCRs and highlight the specific roles that these receptors play in inflammation and immune modulation.

Roles of thromboxane A(2) and prostacyclin in the development of atherosclerosis in apoE-deficient mice

Production of thromboxane (TX) A2 and PG I2/prostacyclin (PGI2) is increased in patients with atherosclerosis. However, their roles in atherogenesis have not been critically defined. To examine this issue, we cross-bred atherosclerosis-prone apoE-deficient mice with mice deficient in either the TXA receptor (TP) or the PGI receptor (IP). Although they showed levels of serum cholesterol and triglyceride similar to those of apoE-deficient mice, apoE-/-TP-/- mice exhibited a significant delay in atherogenesis, and apoE-/-IP-/- mice exhibited a significant acceleration in atherogenesis compared with mice deficient in apoE alone. The plaques in apoE-/-IP-/- mice showed partial endothelial disruption and exhibited enhanced expression of ICAM-1 and decreased expression of platelet endothelial cell adhesion molecule 1 (PECAM-1) in the overlying endothelial cells compared with those of apoE-/-TP-/- mice. Platelet activation with thrombin ex vivo revealed higher and lower sensitivity for surface P-selectin expression in platelets of apoE-/-IP-/- and apoE-/-TP-/- mice, respectively, than in those of apoE-/- mice. Intravital microscopy of the common carotid artery revealed a significantly greater number of leukocytes rolling on the vessel walls in apoE-/-IP-/- mice than in either apoE-/-TP-/- or apoE-/- mice. We conclude that TXA2 promotes and PGI2 prevents the initiation and progression of atherogenesis through control of platelet activation and leukocyte-endothelial cell interaction.

Long-term evaluation of lung function in patients affected by scleroderma treated with cyclic iloprost infusions

OBJECTIVE

The aim of this study was to evaluate pulmonary function in patients suffering from scleroderma treated for 3 years with cyclic iloprost infusions.

METHODS

Thirty patients affected by scleroderma (five men and 25 women, mean age 49.3 years, mean disease duration 8 years, 19 with limited and 11 with diffuse disease patterns) were treated for 5 consecutive days every 4 months for 3 years with iloprost. Pulmonary function was evaluated at baseline and after 3 years. At the end of the trial, color Doppler echocardiography was performed in 26 of the patients.

RESULTS

Spirometric parameters did not significantly change after 3 years of therapy when expressed as percentage of the predicted normal value. Diffusing lung capacity for carbon monoxide decreased at the limit of statistical significance. No patients developed clinical pictures suggestive of severe pulmonary arterial hypertension, which was confirmed in 26 subjects by evaluation of estimated pulmonary artery systolic pressure.

CONCLUSIONS

This long-term study showed that lung function remained substantially stable after 3 years of treatment with cyclic iloprost infusions. No cases of severe pulmonary hypertension were observed.

Altered maturation of peripheral blood dendritic cells in patients with breast cancer

Tumours have at least two mechanisms that can alter dendritic cell (DC) maturation and function. The first affects the ability of haematopoietic progenitors to differentiate into functional DCs; the second affects their differentiation from CD14+ monocytes, promoting an early but dysfunctional maturation. The aim of this study was to evaluate the in vivo relevance of these pathways in breast cancer patients. For this purpose, 53 patients with invasive breast cancer were compared to 68 healthy controls. To avoid isolation or culture procedures for enrichment of DCs, analyses were directly performed by flow cytometry on whole-blood samples. The expression of surface antigens and intracellular accumulation of regulatory cytokines upon LPS stimulation were evaluated. The number of DCs, and in particular of the myeloid subpopulation, was markedly reduced in cancer patients (P<0.001). Patient DCs were characterized by a more mature phenotype compared with controls (P=0.016), and had impaired production of IL-12 (P<0.001). These alterations were reverted by surgical resection of the tumour. To investigate the possible role of some tumour-related immunoactive soluble factors, we measured the plasmatic levels of vascular endothelial growth factor, IL-10 and spermine. A significant inverse correlation between spermine concentration and the percentage of DCs expressing IL-12 was found. Evidence was also obtained that in vitro exposure of monocyte-derived DCs to spermine promoted their activation and maturation, and impaired their function. Taken together, our results suggest that both the above-described mechanisms could concomitantly act in breast cancer to affect DC differentiation, and that spermine could be a mediator of dysfunctional maturation of DCs.

Serum non-esterified very long-chain PUFA are associated with markers of endothelial dysfunction

The objective of this study was to investigate the pattern of serum non-esterified fatty acid (NEFA) fraction in association with atherosclerosis development. We have studied possible relationships between eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and arachidonic acid (AA) in the NEFA fraction and biochemical markers of endothelial activation or dysfunction. The study population consisted of 152 elderly men with high risk for coronary heart disease. The composition of fasting serum NEFA was analysed by gas-liquid chromatography. Endothelial activation was evaluated using biochemical analyses of some markers of endothelial function. A significant inverse linear association was found between serum non-esterified EPA and DHA, and soluble vascular cell adhesion molecule-1 (sVCAM-1) (P=0.02 and 0.001, respectively). An inverse linear association was found between serum non-esterified AA and sVCAM-1 (P=0.001) and von Willebrand Factor (P=0.005). The significant inverse associations for DHA and AA were independent from the serum content of other NEFAs. Taken together, negative associations were found between sVCAM-1 and the serum levels of non-esterified DHA, EPA and AA. The inverse relation between the levels of sVCAM-1 and very long-chain n-3 fatty acids might indicate an anti-inflammatory effect of the latter.