Analogies and differences between cirrhotic cardiomyopathy and hepatopulmonary syndrome

Cirrhotic cardiomyopathy and hepatopulmonary syndrome are two quite frequent clinical entities that may complicate the course of liver cirrhosis. The common pathophysiological origin and the same clinical presentation make them difficult to compare. Cirrhotic cardiomyopathy and hepatopulmonary syndrome may start with dyspnea and breathlessness but the former is characterized by a chronic cardiac dysfunction and the latter by a defect of oxygenation due to pulmonary shunts formation. The focus is to differentiate them as soon as possible since the treatment is different until the patient undergoes liver transplant that is the real unique cure for them.

How Can Interleukin-1 Receptor Antagonist Modulate Distinct Cell Death Pathways?

Multiple mechanisms of cell death exist (apoptosis, necroptosis, pyroptosis) and the subtle balance of several distinct proteins and inhibitors tightly regulates the cell fate toward one or the other pathway. Here, by combining coimmunoprecipitation, enzyme assays, and molecular simulations, we ascribe a new role, within this entangled regulatory network, to the interleukin-1 receptor antagonist (IL-1Ra). Our study enlightens that IL-1Ra, which usually inhibits the inflammatory effects of IL-1α/β by binding to IL-1 receptor, under advanced pathological states prevents apoptosis and/or necroptosis by noncompetitively inhibiting the activity of caspase-8 and -9. Consensus docking, followed by cumulative 10 μs of molecular dynamics simulations unprecedentedly reveal that IL-1Ra binds both caspases at their dimeric interface, preventing, in this manner, the formation of their catalytically/signaling active form. The resulting IL-1Ra/caspase-8(9) adducts are stabilized by hydrophobic and by few key hydrogen bonding interactions, formed by residues fully conserved across distinct caspases (-3, -6, -7, -8, and -9), and closely resemble the binding mode of the caspases inhibitors XIAP (X-linked inhibitor of apoptosis) and c-FLIP (cellular FLICE-like inhibitory protein). Tight regulation of the different forms of cell death has a major impact on distinct human illnesses (i.e., cancer, neurodegeneration, ischemic injury, atherosclerosis, viral/bacterial infections, and immune reaction). Hence, our study, pinpointing IL-1Ra as new actor of the intricate cell death regulatory network and gaining an atomic-scale understanding of its mechanism may open new avenues toward innovative therapeutic strategies to tackle major human diseases.

Portopulmonary hypertension and hepatorenal syndrome. Two faces of the same coin

Portopulmonary hypertension and hepatorenal syndrome are both severe local hypertensive complications of liver cirrhosis and portal hypertension. Both are characterized by vasoconstrictive manifestations regarding pulmonary and renal vascular network, respectively. This review addresses the mechanisms underlying the development of vasoconstriction that leads to local vascular hypertension in the lung and in the kidney with the result of organ dysfunction. Potential therapeutic options are available for the management of these two syndromes as a bridge for liver transplantation; clinical efficacy depends in part on the time and rapidity of intervention and in part on how serious the chain of events is that has triggered the entire vasoconstrictive process.

Cirrhotic cardiomyopathy in the pre- and post-liver transplantation phase

Patients with advanced liver cirrhosis may develop a clinical syndrome characterized by a blunted contractile responsiveness to stress and/or altered diastolic relaxation, called "cirrhotic cardiomyopathy." This syndrome, which is initially asymptomatic, is often misdiagnosed due to the presence of symptoms that characterize other disorders present in patients with advanced liver cirrhosis, such as exercise intolerance, fatigue, and dyspnea. Stress and other conditions such as liver transplantation and transjugular intrahepatic portosystemic shunt (TIPS) may unmask this syndrome. Liver transplantation in this group of patients results in a clinical improvement and can be a cure for the cardiomyopathy. However, post-transplant prognosis depends on the identification of cirrhotics with cardiomyopathy in the pre-transplant phase; an early diagnosis of cirrhotic cardiomyopathy in the pre-transplant phase may avoid an acute onset or worsening of cardiac failure after liver transplantation. Since a preserved left ventricular ejection fraction may mask the presence of cirrhotic cardiomyopathy, the use of newer noninvasive diagnostic techniques (i.e. tissue Doppler, myocardial strain) is necessary to identify cirrhotics with this syndrome, in the pre-transplant phase. A pre-transplant treatment of heart failure in cirrhotics with cardiomyopathy improves the quality of life in this phase and reduces the complications during and immediately after liver transplantation. Since specific therapies for cirrhotic cardiomyopathy are lacking, due to the absence of a clear understanding of the pathophysiology of the cardiomyopathy, further research in this field is required.

Hepatic PPARs: their role in liver physiology, fibrosis and treatment

Complex molecular and cellular mechanisms are involved in the pathway of liver fibrosis. Activation and transformation of hepatic stellate cells (HSCs) are considered the two main reasons for the cause and development of liver fibrosis. The peroxisome proliferator-activated receptors (PPARs) belonging to the family of ligand-activated transcription factors play a key role in liver homeostasis, regulating adipogenesis and inhibiting fibrogenesis in HSCs. Normal transcriptional function of PPARs contributes to maintain HSCs in quiescent phase. A reduced expression of PPARs in HSCs greatly induces a progression of liver fibrosis and an increased production of collagen. Here, we discuss role and function of PPARs and we take into consideration molecular factors able to reduce PPARs activity in HSCs. Finally, although further validations are needed, we illustrate novel strategies available from in vitro and animal studies on how some PPARs-agonists have been proved effective as antifibrotic substances in liver disease.

Intracellular function of interleukin-1 receptor antagonist in ischemic cardiomyocytes

Background

Loss of cardiac myocytes due to apoptosis is a relevant feature of ischemic heart disease. It has been described in infarct and peri-infarct regions of the myocardium in coronary syndromes and in ischemia-linked heart remodeling. Previous studies have provided protection against ischemia-induced cardiomyocyte apoptosis by the anti-inflammatory cytokine interleukin-1 receptor-antagonist (IL-1Ra). Mitochondria triggering of caspases plays a central role in ischemia-induced apoptosis. We examined the production of IL-1Ra in the ischemic heart and, based on dual intra/extracellular function of some other interleukins, we hypothesized that IL-1Ra may also directly inhibit mitochondria-activated caspases and cardiomyocyte apoptosis.

Methodology/Principal Findings

Synthesis of IL-1Ra was evidenced in the hearts explanted from patients with ischemic heart disease. In the mouse ischemic heart and in a mouse cardiomyocyte cell line exposed to long-lasting hypoxia, IL-1Ra bound and inhibited mitochondria-activated caspases, whereas inhibition of caspase activation was not observed in the heart of mice lacking IL-1Ra (Il-1ra−/−) or in siRNA to IL-1Ra-interfered cells. An impressive 6-fold increase of hypoxia-induced apoptosis was observed in cells lacking IL-1Ra. IL-1Ra down-regulated cells were not protected against caspase activation and apoptosis by knocking down of the IL-1 receptor, confirming the intracellular, receptor-independent, anti-apoptotic function of IL-1Ra. Notably, the inhibitory effect of IL-1Ra was not influenced by enduring ischemic conditions in which previously described physiologic inhibitors of apoptosis are neutralized.

Conclusions/Significance

These observations point to intracellular IL-1Ra as a critical mechanism of the cell self-protection against ischemia-induced apoptosis and suggest that this cytokine plays an important role in the remodeling of heart by promoting survival of cardiomyocytes in the ischemic regions.

Alterations in the interleukin-1/interleukin-1 receptor antagonist balance modulate cardiac remodeling following myocardial infarction in the mouse

Background

Healing after acute myocardial infarction (AMI) is characterized by an intense inflammatory response and increased Interleukin-1 (IL-1) tissue activity. Genetically engineered mice lacking the IL-1 receptor (IL-1R1-/-, not responsive to IL-1) or the IL-1 receptor antagonist (IL-1Ra, enhanced response to IL-1) have an altered IL-1/IL-1Ra balance that we hypothesize modulates infarct healing and cardiac remodeling after AMI.

Methods

IL-1R1-/- and IL-1Ra-/- male mice and their correspondent wild-types (WT) were subjected to permanent coronary artery ligation or sham surgery. Infarct size (trichrome scar size), apoptotic cell death (TUNEL) and left ventricular (LV) dimensions and function (echocardiography) were measured prior to and 7 days after surgery.

Results

When compared with the corresponding WT, IL-1R1-/- mice had significantly smaller infarcts (−25%), less cardiomyocyte apoptosis (−50%), and reduced LV enlargement (LV end-diastolic diameter increase [LVEDD], −20%) and dysfunction (LV ejection fraction [LVEF] decrease, −50%), whereas IL-1Ra-/- mice had significantly larger infarcts (+75%), more apoptosis (5-fold increase), and more severe LV enlargement (LVEDD increase,+30%) and dysfunction (LVEF decrease, +70%)(all P values <0.05).

Conclusions

An imbalance in IL-1/IL-1Ra signaling at the IL-1R1 level modulates the severity of cardiac remodeling after AMI in the mouse, with reduced IL-1R1 signaling providing protection and unopposed IL-1R1 signaling providing harm.

Cirrhotic cardiomyopathy

Cirrhotic cardiomyopathy is a clinical syndrome in patients with liver cirrhosis characterized by an abnormal and blunted response to physiologic, pathologic, or pharmacologic stress but normal to increased cardiac output and contractility at rest. As many as 50% of cirrhotic patients undergoing liver transplantation show signs of cardiac dysfunction, and 7% to 21% of deaths after orthotopic liver transplantation result from overt heart failure. In this review, we critically evaluate the existing literature on the pathophysiology and clinical implications of cirrhotic cardiomyopathy.

Portosystemic shunts in a large cohort of patients with liver cirrhosis: detection rate and clinical relevance

BACKGROUND

This study aimed to determine the detection rate and clinical relevance of portosystemic collaterals.

METHODS

We studied 326 cirrhotics. Portosystemic collaterals, portal vein diameter, and splenic area were evaluated by color Doppler sonography; esophageal varices were detected by endoscopy.

RESULTS

Of the cirrhotics, 130 had portosystemic collaterals (39.9% total, left gastric vein 11%, paraumbilical vein 7.4%, splenorenal shunts 13.8%, and combined shunts 7.7%). Cirrhotics without portosystemic collaterals or with a paraumbilical vein had a significantly narrower portal vein diameter than cirrhotics with a left gastric vein (P < 0.001). Cirrhotics with a paraumbilical vein had a significantly smaller splenic area than cirrhotics with a left gastric vein (P < 0.001), splenorenal shunts (P < 0.001), combined shunts (P < 0.001), or without portosystemic collaterals (P < 0.05). A significant association between portosystemic collaterals and Child's classes or presence and type of esophageal varices was found (P < 0.0001 and P = 0.0004, respectively). The highest prevalence of Child's class C and large (F-3) esophageal varices was found in cirrhotics with a left gastric vein (41.7% and 36.1%, respectively), whereas esophageal varices were absent in 47.4% of cirrhotics without portosystemic collaterals and in 58.3% of cirrhotics with a paraumbilical vein.

CONCLUSIONS

The left gastric vein is associated with some sonographic and clinical markers of disease severity, whereas the absence of portosystemic collaterals or the presence of paraumbilical veins seems to identify cirrhotics with markers predictive of a more favorable clinical course.

Endothelin-1 induces connective tissue growth factor expression in cardiomyocytes

Endothelin (ET)-1 is a vasoconstrictor involved in cardiovascular diseases. Connective tissue growth factor/CCN2 (CTGF) is a fibrotic mediator overexpressed in human atherosclerotic lesions, myocardial infarction, and hypertension. In different cell types CTGF regulates cell proliferation/apoptosis, migration, and extracellular matrix (ECM) accumulation and plays important roles in angiogenesis, chondrogenesis, osteogenesis, tissue repair, cancer and fibrosis. In the present study, we investigated the ET-1 signaling which triggers CTGF expression in cultured adult mouse atrial-muscle HL-1 cells used as a model system. ET-1 activated the CTGF promoter and induced CTGF expression at both mRNA and protein levels. Real-time PCR analysis revealed CTGF induction also in isolated rat heart preparations perfused with ET-1. Several intracellular signals elicited by ET-1 via ET receptors and even Epidermal Growth Factor Receptor (EGFR) contributed to the up-regulation of CTGF, including ERK activation and induction of the AP-1 components c-fos and c-jun, as also evaluated by ChIP analysis. Moreover, in cells treated with ET-1 the expression of ECM component decorin was abolished by CTGF silencing, indicating that CTGF is involved in ET-1 induced ECM accumulation not only in a direct manner but also through downstream effectors. Collectively, our data indicate that CTGF could be a mediator of the profibrotic effects of ET-1 in cardiomyocytes. CTGF inhibitors should be considered in setting a comprehensive pharmacological approach towards ET-1 induced cardiovascular diseases.

Postmeal portal flow variations in HCV-related chronic hepatitis and liver cirrhosis with and without hyperdynamic syndrome

BACKGROUND

Doppler ultrasonography (US) of portal blood flow and portal flow volume (PFV) are useful to define changes in portal hemodynamics of patients with chronic liver diseases. The meal test with postmeal PFV measurements is generally accepted as a reproducible noninvasive test to evaluate the severity of portal hypertension. The aim of this study was to evaluate whether monitoring PFV changes after ingestion of a standard meal would be useful to characterize patients with chronic hepatitis or liver cirrhosis in the presence or absence of hyperdynamic syndrome (HS) characterized by elevated PFV, splenomegaly, systemic hypotension and/or increased cardiac output.

PATIENTS AND METHODS

Thirty-seven patients (22 men and 15 women, median age 53 years) with hepatitis C virus infection and 20 healthy age- and sex-matched volunteers (Controls) were enrolled in the study. There were 19 (51.4%) patients with chronic hepatitis (Group A) and 18 (48.6%) with ultrasonographic evidence of liver cirrhosis (Child-Pugh class B), 9 of whom had an HS (Group B) while the remainder (Group C) did not. Each patient underwent liver color Doppler US and the test was repeated 30, 60 and 90 minutes after administration of a standard meal (300 kcal fluid meal containing 12 g of proteins, 11.6 g of lipids and 36.8 g of carbohydrates).

RESULTS

The baseline PFV did not differ (p=NS) between Controls and both Groups A and C, while the PFV of Group B patients was significantly (p<0.01) higher. After 30 minutes, the PFV increased (p<0.01) both in Controls and Group A patients, while the differences were not significant in cirrhotic patients (Groups B and C). Our study confirmed that the postmeal PFV increases in both healthy individuals and in patients with chronic hepatitis, while in cirrhotic patients no significant changes occur. In conclusion, monitoring the portal blood flow in cirrhotic patients before and after administration of a standard meal might be a suitable test to evaluate potential disturbances of the flow itself. Moreover, the test could be useful to determine optimal pharmacological or surgical interventions aimed at restoring a better flow to the liver by reducing or favouring the occurrence of spontaneous mesenteric-systemic venous shunts.

Sudden coronary death, fatal acute myocardial infarction and widespread coronary and myocardial inflammation

BACKGROUND

T-lymphocyte activation within atherosclerotic plaque, and widespread to the myocardium, has been shown in patients with acute coronary syndromes.

OBJECTIVE

To investigate the presence of T-lymphocyte infiltrate at different stages of acute coronary syndromes by studying patients with sudden coronary death, acute myocardial infarction (AMI) and healed infarction, in comparison with patients with myocarditis and patients with non-ischaemic heart failure.

METHODS

72 cases were studied at autopsy: 12 dying of sudden coronary death (group 1), 12 dying <4 weeks (group 2) and 12 dying >4 months after AMI (group 3), 12 with active lymphocytic myocarditis (group 4), 12 with hypertensive heart disease (group 5), and 12 control subjects (group 6). Light microscopy was performed to measure the number of activated T-lymphocytes (CD3+/DR+) in the myocardium and coronary artery wall, and intercellular adhesion molecule-1 (ICAM-1) expression in the myocardium.

RESULTS

Activated T-lymphocyte infiltrates and ICAM-1 myocardial expression in both remote and peri-infarction regions and activated T-lymphocytes within the epicardial coronary artery wall of both the infarct- and non-infarct-related arteries were found in groups 1, 2 and 3, whereas myocardial, but not coronary, infiltrates were found in groups 4 (p<0.001 vs groups 1, 2 and 3 for coronary infiltrates). Groups 5 and 6 had no evidence of myocardial or coronary inflammation (p<0.001 vs groups 1, 2 and 3).

CONCLUSIONS

The study shows the presence of a lymphocytic infiltrate in both coronary arteries and myocardium and a proinflammatory phenotype shift in the myocardium associated with acute coronary thrombosis in patients dying suddenly, shortly, or even late after coronary thrombosis.

Anakinra, a recombinant human interleukin-1 receptor antagonist, inhibits apoptosis in experimental acute myocardial infarction

BACKGROUND

Experimental interleukin-1 receptor antagonist gene overexpression has shown that interleukin-1 receptor antagonist is cardioprotective during global cardiac ischemia. The aim of the present study was to test the impact of an exogenous recombinant human interleukin-1 receptor antagonist (anakinra) in experimental acute myocardial infarction.

METHODS AND RESULTS

Two animal studies were conducted: one of immediate anakinra administration during ischemia in the mouse and one of delayed anakinra administration 24 hours after ischemia in the rat. Seventy-eight Institute of Cancer Research mice and 20 Wistar rats underwent surgical coronary artery ligation (or sham operation) and were treated with either anakinra 1 mg/kg or NaCl 0.9% (saline). Treatment was administered during surgery and then daily for 6 doses in the mice and starting on day 2 daily for 5 doses in the rats. Twenty-eight mice underwent infarct size assessment 24 hours after surgery, 6 saline-treated mice and 22 mice treated with increasing doses of anakinra (1 mg/kg [n=6], 10 mg/kg [n=6], and 100 mg/kg [n=10]); 6 mice were euthanized at 7 days for protein expression analysis. The remaining animals underwent transthoracic echocardiography before surgery and 7 days later just before death. Cardiomyocyte apoptosis was measured in the peri-infarct regions. The antiapoptotic effect of anakinra was tested in a primary rat cardiomyocyte culture during simulated ischemia and in vitro on caspase-1 and -9 activities. At 7 days, 15 of the 16 mice (94%) treated with anakinra were alive versus 11 of the 20 mice (55%) treated with saline (P=0.013). No differences in infarct size at 24 hours compared with saline were observed with the 1- and 10-mg/kg doses, whereas a 13% reduction in infarct size was found with the 100-mg/kg dose (P=0.015). Treatment with anakinra was associated with a significant reduction in cardiomyocyte apoptosis in both the immediate and delayed treatment groups (3.1+/-0.2% versus 0.5+/-0.3% [P<0.001] and 4.2+/-0.4% versus 1.1+/-0.2% [P<0.001], respectively). Compared with saline-treated animals, anakinra-treated mice and rats showed signs of more favorable ventricular remodeling. In vitro, anakinra significantly prevented apoptosis induced by simulated ischemia and inhibited caspase-1 and -9 activities.

CONCLUSIONS

Administration of anakinra within 24 hours of acute myocardial infarction significantly ameliorates the remodeling process by inhibiting cardiomyocyte apoptosis in 2 different experimental animal models of AMI. This may open the door for using anakinra to prevent postischemic cardiac remodeling and heart failure.

Prostacyclin in liver disease: a potential therapeutic option

Complex molecular and cellular mechanisms are involved in the initiation and progression of hepatic fibrosis. Recent studies have shown that hepatic stellate cells, endothelin, cytokines and prostacyclin play crucial roles in this pathology. Prostacyclin exerts vasorelaxant, antioxidant and antifibrotic properties that prevent the development of fibrosis and cirrhosis in liver diseases. In this editorial, the authors discuss some of the molecular and cellular mechanisms involved in the initiation and progression of liver fibrosis and the role played by prostacyclin in counteracting it. At the moment, however, only limited information is available from clinical studies demonstrating the effectiveness of prostacyclin in liver diseases and this makes it difficult to draw any conclusions; further efforts are necessary to verify whether prostacyclin, alone or in combination with other drugs, may be a valid therapeutic option in liver diseases.

Portal diameter in the diagnosis of esophageal varices in 266 cirrhotic patients: which role?

The aim was to evaluate the predictability of portal diameter (PD) in the diagnosis of esophageal varices (EV) and of large size EV (F3EV) in a large series of patients with cirrhosis. Two-hundred sixty-six persons with cirrhosis (M:F = 153:113; mean age 65.4 +/- 10 y) were studied by abdominal sonography and upper endoscopy. Portal hypertensive gastropathy (PHG) was found in 16.1% and EV was found in 60.9% of patients. Only Child's class (B vs. A: OR 3.4, p < 0.0001; C vs. A: OR 10.3, p < 0.0001; C vs. B: OR 3.1, p = 0.01) and age (OR 1.04, p = 0.03) were independent predictors of EV, whereas PD was not (p = 0.4). Child's class and age were also the only independent predictors of F3EV. Mean PD showed a slight and not significant increase in PHG patients compared with patients with negative endoscopy, a reduction in F1EV patients and then a progressive increase in F2EV and F3EV patients. Patients with PD <12 mm showed a significantly higher prevalence of F1-F2EV (p < 0.05) and a near-significant lower prevalence of endoscopies negative for EV (p = 0.06) than patients with 12 < or = PD < or = 13 mm. PD was not able to predict EV or F3EV in a large series of patients with cirrhosis. The oscillatory trend of PD, proceeding from patients with negative endoscopy to F3EV patients, seems to indicate that EV may unload portal pressure in the initial phases of portal hypertension.

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.

Iloprost enhances portal flow velocity and volume in patients with systemic sclerosis

BACKGROUND

Iloprost, a prostacyclin analog, reduces hepatic microcirculatory damage after ischemia-reperfusion injury in animal liver models. The objective of this study was to evaluate whether the portal flow velocity changes after Iloprost infusion in patients with systemic sclerosis and Raynaud's phenomenon, who usually have increased risk of microvascular thrombosis and transient liver disturbances.

PATIENTS AND METHODS

Fifteen patients (3 males and 12 females, median age 58 years, range 47-66 years), with systemic sclerosis and Raynaud's phenomenon, were exclusively treated with an infusion of Iloprost (2 ng/kg/min, 6 h/day) for 5 days. In each subject, the portal flow velocity (PV, cm/sec) and portal flow volume (PFV, mL/min) were obtained by using portal color Doppler ultrasonography equipment.

RESULTS

Iloprost administration significantly (p<0.001) increased both the PV (23.6+/-3.4 cmlsec vs. 29.1+/-3.9 cm/sec) and PFV (1748.8+/-310. 7 mL/min vs. 2254.9+/-404.1 mL/min) values.

CONCLUSION

Hepatic perfusion significantly improved after Iloprost administration, suggesting that such treatment might be useful in preventing vascular complications in patients with systemic sclerosis. Iloprost improves the portal hemodynamics, favoring local microvascular patency, and its effectiveness may be safely monitored by using portal color Doppler ultrasonography.

Interleukin-1 receptor antagonist levels correlate with extent of myocardial loss in patients with acute myocardial infarction

BACKGROUND

Interleukin-1 receptor antagonist (IL-1Ra) levels are elevated early in patients with acute myocardial infarction (MI) and often precede release of markers of necrosis; however, IL-1Ra levels did not correlate previously with infarct size and prognosis in such patients.

HYPOTHESIS

The goal of our study was to evaluate prospectively the correlation between IL-1Ra levels upon emergency department (ED) presentation and the extent of myocardial necrosis and prognosis in patients with ST-segment elevation MI.

METHODS

Levels of IL-1Ra were measured upon ED presentation in 44 consecutive patients (40 men, aged 55 +/- 10 years). Peak values of creatine kinase (CK) and CK-MB were determined during hospitalization, and left ventricular ejection fraction (LVEF) was evaluated by echocardiography before discharge. All patients were followed prospectively and underwent clinical and echocardiographic assessment at 42 +/- 3 months after the infarction.

RESULTS

Levels of IL-1Ra upon ED presentation correlated directly with CK (p = 0.002) and CK-MB (p = 0.01) peak levels and correlated inversely with LVEF before discharge (p = 0.009). Patients with in-hospital adverse events had significantly higher IL-1Ra levels upon ED admission (n = 10,2620 +/- 4706 pg/ml) than those without events (n = 34,598 +/- 457 pg/ml) (p = 0.015).

CONCLUSIONS

In patients with MI, levels of IL-1Ra upon ED presentation correlated significantly with the extent of myocardial necrosis, as measured by cardiac enzymes peak and reduction of LVEF, and are predictive of in-hospital events. Results of this study may influence early therapeutic approach in patients with acute MI.

Genotypes and haplotypes in the IL-1 gene cluster: analysis of two genetically and diagnostically distinct groups of Alzheimer patients

Increased risk of Alzheimer's disease (AD) has been associated with polymorphisms in the IL-1 gene cluster, and in particular with the IL-1alpha-889 T/T genotype. However, this association is still unclear, and needs further investigation. In order to clarify the role of these polymorphisms in the complex pathogenesis of AD we examined genotype and haplotype frequencies of the two C-to-T SNPs at position -889 and -551 in the IL-1alpha and IL-1beta genes, respectively, and of the 86 bp VNTR intron-2 polymorphisms in the IL-1Ra gene. The analysis was performed in two genetically and diagnostically distinct groups of sporadic AD from Italy and the USA. In the Italian group a significant association between the IL-1alpha-889 T/T genotype and AD (OR=3.022, 95% CI: 1.001-9.119) was found, whereas no difference was found in the group from the USA. Results were also compared with previously published studies that analyzed the same IL-1 polymorphisms in AD. In both groups, the analysis of the estimated haplotypes shows that AD patients and controls who carry the IL-1beta-511 C allele, were also more frequently carriers of the IL-1Ra 1 allele (haplotypes -C-1). The total frequency of the two -C-1 haplotypes (C-C-1 plus T-C-1) was about one half of the total frequency of the eight estimated haplotypes. This was confirmed by significant linkage disequilibrium between these two loci in both the Italian and USA groups. In the Italian group a weak association of the T-C-2 haplotype with the disease (OR=1.648, 95% CI: 1.519-1.788) was also found, whereas in the USA group no difference was found. Although ours and other published data on different samples of Caucasian and non-Caucasian AD show a great heterogeneity in the frequencies of the IL-1alpha-889, the IL-1beta-511 and the IL-1Ra VNTR gene polymorphisms, we confirm the role of the IL-1alpha-889 T/T genotype as a risk factor for sporadic AD, and show the presence of an allelic association between IL-1beta C and IL-1Ra 1 alleles in both the Italian and the USA groups, confirmed by the presence of significant levels of linkage disequilibrium between these two loci.

Endothelial dysfunction and activation as an expression of disease: role of prostacyclin analogs

The endothelium is now considered a real endocrine-paracrine organ, important not only as a structural barrier between the circulation and surrounding tissue, but also because it plays an essential role for local hemodynamics, releasing substances that modulate the vascular calibre and blood cell activation. Here, after a brief but detailed analysis of the importance of the endothelium in vascular homeostasis, in the control of coagulation and in the relations with the different blood cells, we will explain the concept of endothelial dysfunction (altered NO release) and activation (amplified adhesion molecule expression) in inflammatory, connective tissue and post-trasplantation diseases. Furthermore, this review will focus on the activity of prostacyclin and synthetic analogs, especially their ability to interact with the vasodilatation system and their role in modulating cell interaction by surface adhesion molecule expression, cytokines and growth factors release as well as gene transcription factors. Finally, we will consider the therapeutic role of prostacyclin analogs in the prevention and treatment of connective tissue diseases.

Iloprost: an adjunctive approach to chronic viral hepatitis treatment

Chronic viral liver disease may evolve to cirrhosis. The medical treatment to slow down this passage is based on anti-viral and anti-fibrotic properties of interferon. Recently, we evidenced significant increase of portal vein flow velocity and volume after a prostacyclin analog (iloprost) infusion in subjects without and with chronic viral hepatitis. On the basis of these results and considering both the pathophysiology of viral liver disease and the mechanism of action of iloprost in portal microcirculation, we hypothesize that it may be of some efficacy in chronic liver disease ameliorating the portal hemodynamics and producing an anti-oxidant liver effect.

Assessment of systemic inflammation and infective pathogen burden in patients with cardiac syndrome X

Inflammation plays a key role in coronary artery disease (CAD), but whether it is involved in the pathogenesis of syndrome X (SX) is not known. Thus, we assessed the presence of systemic inflammation in patients with SX and its possible relation to infections from Helicobacter pylori, Chlamydia pneumoniae, cytomegalovirus, and Epstein-Barr virus. We studied 55 patients with SX (57 +/- 8 years old; 27 women), 49 with stable angina and obstructive CAD (56 +/- 8 years old; 24 women), and 60 healthy controls (57 +/- 11 years old; 24 women). Plasma levels of high-sensitivity C-reactive protein and interleukin-1 receptor antagonist were measured in all patients. Infection from Helicobacter pylori, Chlamydia pneumoniae, cytomegalovirus, and Epstein-Barr virus was assessed in 43 patients with SX, 40 patients with CAD, and in 39 controls. Patients with SX had lower serum levels of C-reactive protein than did patients with CAD (4.06 +/- 6.8 vs 5.99 +/- 7.8 mg/L, p = 0.013) but higher levels of C-reactive protein than did controls (1.75 +/- 1.98 mg/L; p = 0.008). Plasma levels of interleukin-1 receptor antagonist were higher in patients with CAD (570 +/- 738 pg/ml) and patients with SX (494 +/- 677 pg/ml) than in controls (254 +/- 174, pg/ml; p = 0.0003 vs CAD and p = 0.013 vs SX) but did not differ significantly between patients with CAD or SX (p = 0.20). There were no differences across groups in the prevalence of infection from Helicobacter pylori, Chlamydia pneumoniae, cytomegalovirus, and Epstein-Barr virus and in the prevalence of 1, 2, 3, and 4 infections (p = 0.99). Among patients with SX, no correlation was found between markers of inflammation and indexes of disease activity (angina episodes, exercise test results). Our data show evidence of increased low-grade systemic inflammation in patients with cardiac SX, which was unrelated to an increased infectious pathogen burden.

Widespread myocardial inflammation and infarct-related artery patency

BACKGROUND

Diffuse coronary vascular inflammation is associated with acute coronary syndromes. However, it is unknown whether inflammation also occurs within the myocardium. Therefore, this study was aimed at assessing the presence of activated cells in unaffected remote myocardium of patients with acute myocardial infarction (AMI), in comparison to the peri-infarct region from the same cases, and in comparison to myocardial specimens from control hearts.

METHODS AND RESULTS

Sixteen patients dying 1 to 12 weeks after AMI and 16 control subjects were selected at autopsy. Myocardial specimens were taken at remote unaffected viable regions and at peri-infarct regions in cases with AMI. Confocal microscopy was performed to measure the number of activated cells (DR+), T-lymphocytes (CD3+), and activated T-lymphocytes (CD3+/DR+). Activated cells and activated T-lymphocytes were found in remote unaffected regions in 11 of 16 cases (69%), in peri-infarct zone in all cases (100%), and in none of the control hearts (0%, P<0.001 versus others). A greater myocardial inflammatory burden in remote regions but not in peri-infarct regions was associated with persistent infarct-related artery occlusion (P<0.05).

CONCLUSIONS

This study for the first time shows the presence of activated T-lymphocytes in remote unaffected myocardial regions in approximately two thirds of patients with recent AMI. Because these cells are associated with persistent infarct-related artery occlusion, our data may suggest that an antigenic stimulus present also in the myocardium triggers an immune response that may be critical to precipitate artery occlusion.

Improved Hepatic Perfusion After Iloprost Infusion in Patients with HCV Chronic Infection: A Pilot Study with Possible Therapeutic Implications

We performed a pilot study to evaluate whether portal flow volume (PFV) changed in subjects with chronic hepatitis C virus (HCV) infection with respect to control patients after infusion of iloprost, a prostacyclin analog. Six subjects with chronic HCV infection and arteriopathy of the lower limbs (CHCVIA) and 4 control patients affected only by HCV infection (CHCV) were studied with color Doppler sonography. CHCVIA patients were examined before and after 3 days of iloprost infusion, and CHCV patients were examined before and after 3 days with no treatment. In each patient, PFV was obtained after calculating portal flow velocity (PV), portal diameter, and portal vein cross-sectional area. The mean difference between basal and final values of the PFV of CHCVIA patients was significant (p = 0.03), as was the difference in the PFV (final values expressed as percent of basal values) in CHCVIA patients compared with those obtained in the CHCV patients (p = 0.01). We have observed significant improvement in hepatic perfusion in CHCVIA patients compared with CHCV patients after iloprost infusion. In light of these results, we suggest some possible therapeutic implications in patients with HCV infection. Further studies are necessary to confirm this hypothesis.

Early interleukin-1 receptor antagonist elevation in patients with acute myocardial infarction

OBJECTIVES

We sought to evaluate interleukin-1 receptor antagonist (IL-1Ra) levels in patients with ST-segment elevation acute myocardial infarction (AMI) upon emergency department (ED) admission in order to assess the sensitivity of such a determination by comparison with common markers of myocardial necrosis.

BACKGROUND

Inflammatory markers are elevated in patients with unstable coronary syndromes, but IL-1Ra levels during the early phases of AMI have not been previously investigated.

METHODS

Levels of IL-1Ra were measured in 44 consecutive patients with AMI and compared with creatine kinase (CK), CK-MB, troponin I, myoglobin, and C-reactive protein (CRP).

RESULTS

Upon admission, 82% of patients had elevated (>230 pg/ml) IL-1Ra levels, compared with 41% of patients with raised CK (p = 0.001), CK-MB (45%, p = 0.002), troponin I (57%, p = 0.027), myoglobin (48%, p = 0.004), and CRP (57%, p = 0.019) levels. The IL-1Ra values were significantly higher in patients with heralded AMI than in those without pre-infarction angina (671 vs. 320 pg/ml, p = 0.013). The sensitivity of IL-1Ra determination increased to 86% when chest pain duration was < or =3 h and to 91% if heralded infarction occurred.

CONCLUSIONS

Our study indicates that, unlike markers of necrosis, an increase of IL-1Ra levels occurs early in patients with AMI, is more significant in those with heralded infarction and symptom onset < or =3 h, and precedes the release of markers of necrosis. Thus, IL-1Ra determination may be an important early adjuvant toward the diagnosis of AMI in the ED.

Right ventricular dilatation after left ventricular acute myocardial infarction is predictive of extremely high peri-infarctual apoptosis at postmortem examination in humans

BACKGROUND

Cardiac remodelling after acute myocardial infarction (AMI) is characterised by molecular and cellular mechanisms involving both left and right ventricles, and biventricular failure identifies patients with an extremely unfavourable prognosis.

AIMS

To assess whether a link exists between increased myocardial apoptotic rates (AR) at sites of recent infarction and patterns of unfavourable cardiac remodelling, such as biventricular enlargement after left ventricular (LV) infarction.

METHODS

Twelve patients with recent AMI involving the LV and not the right ventricle (RV) and with permanent infarct related artery occlusion were selected at necropsy. Gross pathological characteristics, such as LV and RV dilatation, and AR at site of infarction were assessed. Potential false positive results (DNA synthesis and RNA splicing) were excluded from the cell count.

RESULTS

RV enlargement, defined as a tricuspidal ring greater than 120 mm, was found in five cases and was associated with LV dilatation. These patients showed significantly higher AR than the others. When the subjects were divided into three groups according to progressive cardiac remodelling (absence of cardiac dilatation, isolated LV dilatation, and biventricular enlargement), the last group had significantly higher ARs than the other two groups, showing that myocardiocyte apoptosis is increased in more unfavourable forms of cardiac remodelling.

CONCLUSION

Patients with severely unfavourable cardiac remodelling, such as biventricular enlargement, have extremely high myocardiocyte apoptosis at necropsy, even late after LV myocardial infarction, supporting the role of myocardiocyte loss in determining post-infarction adverse remodelling.

Relevance of interleukin-1 receptor antagonist intron-2 polymorphism in ischemic stroke

Evidence of inflammatory phenomena associated with atherosclerotic plaques is extensive. Interleukin-1 (IL-1) is one of the key modulators of the inflammatory response, and its activity is critically regulated by its receptor antagonist (IL-1Ra). A variable number of tandem repeats (VNTR) in intron 2 of the human IL-1Ra shows a common polymorphism that has been related to different production of IL-1Ra and IL-1 proteins. In monocytes, the less common allele 2 has been associated with an increased production of IL-1Ra and a decreased production of IL-1. Moreover, a cooperative effect with a C to T polymorphism in the promoter of IL-1beta gene (C(-511)-->T) has been described. In the present study, we investigated the frequency of these polymorphisms in 110 subjects who survived an ischemic stroke, in 101 healthy age-matched individuals, and in a population-based sample of 1,303 healthy Italians. The frequency of the IL- 1Ra 1/1 genotype was significantly higher in stroke survivors with respect to age-matched controls (77.2 and 45.5%, respectively; p < 0.001), and to the wide group of healthy Italians (77.2 and 51.9%, respectively; p < 0.001). As expected, the estimated frequency of the IL-1Ra allele 1 (Ra*1 allele) in stroke survivors was higher than in age-matched controls (0.851 and 0.664, respectively; p < 0.001) and in healthy Italians (0.851 and 0.717, respectively; p < 0.001). Thus, ischemic stroke survivors that carry the Ra*1 allele showed a strong association with the disease with respect to age-matched controls [odds ratio (OR) = 3.905; 95% confidence interval (CI), 2.110-7.229] and healthy Italians [OR = 3.256 (95% CI, 1.971-5.379)]. No significant association was seen for the IL-1beta (C(-511)-->T) polymorphism. However, in stroke survivors, an association between the Ra*1 allele and the C allele of the IL-1beta (-511) polymorphism was found (p < 0.001). Our results implicate the IL-1Ra gene in the susceptibility to ischemic stroke, and suggest that IL-1Ra genotyping may be useful in the identification of patient subgroups for pharmacological intervention in IL-1 production or actions.

High-risk clinical features predict increased post-infarction myocardial apoptosis and the benefits as a result of an open infarct-related artery

BACKGROUND

Infarct-related artery (IRA) patency after acute myocardial infarction (AMI) is associated with a more favourable clinical course, in particular in patients with high-risk features. As it has been recently reported that IRA patency is associated with a reduced postinfarction apoptotic rate (AR), the aim of our study was to assess whether IRA status late after AMI had a different impact on AR in high- vs. low-risk patients.

METHODS AND RESULTS

Co-localization of TUNEL and caspase-3 was used to calculate the AR at the site of infarction at the time of death in 30 subjects. The Norris coronary prognostic index (NI) was calculated (computing age, presence of pulmonary congestion, heart size and history of previous additional AMI) in order to define the patients' individual risk at the time of hospitalization. According to the NI (< or =7 vs. >7), subjects were divided into low and high risk, as NI >7 carries an approximate threefold higher risk of death. The NI was significantly correlated with the AR at the time of death both in infarct and remote areas. Twenty subjects had IRA occlusion at the time of death, and in these patients AR was significantly higher both in infarct and remote areas (P<0.001 and P=0.009 vs. the others, respectively). However the impact of IRA occlusion on AR was significantly different comparing high- vs. low-risk subjects. In particular, AR at the infarct site was 10-fold higher in the high-risk subjects with IRA occlusion (26.1%[20.4-28.7%]) vs. those with open IRA (2.3%[0.6-3.5%]; P=0.002) and was nonsignificantly different in the low-risk subjects vs. those without IRA occlusion (8.2%[2.5-17.5%] vs. 5.4%[1.5-7.9%]; P=0.48). Similarly, in the high-risk subjects, AR in remote areas was significantly greater in cases with occluded vs. open IRA (0.7%[0.4-0.9%] vs. 0.3%[0.3-0.32%]; P=0.009).

CONCLUSION

A significantly higher AR is associated with IRA occlusion late post AMI in subjects with high-risk clinical features, and not in low-risk patients. The diverse impact of IRA occlusion on AR in subjects with different risk profiles may explain the greater benefit associated with coronary reperfusion in high-risk subjects. The overall lower AR in low-risk subjects, independently from the IRA status, may be correlated with the better long-term prognosis after AMI in this case.

Evidence of CXC, CC and C chemokine production by lymphatic endothelial cells

Although production of chemokines by vascular endothelial cells has been documented, there is only limited information regarding the expression of chemokines by the lymphatic endothelium. Here we used lymphatic endothelial cells (LEC) derived from experimentally induced murine lymphangiomas to investigate the pattern of chemokine expression by these cells. Histological analysis of the lymphatic hyperplasia revealed the presence of leucocytes in the tissues surrounding the lesions, suggesting the presence of chemoattractant activity. A functional chemotactic assay on human polymorphonuclear cells and on purified subpopulations of murine leucocytes using culture supernatants from LEC primary cultures confirmed the presence of chemoattractant activity. The identity of different cytokines of the CXC, CC and C subfamilies was investigated by reverse trancriptase-polymerase chain reaction on total endothelial cell RNA. Amplified fragments corresponding to KC, IP10, Mig-1, BCL, MIP-2, SLC, RANTES, MCP-1, C10, and Lptn were obtained, and confirmed by Southern blot and sequencing. In contrast, MIP-1alpha, MIP-1beta, and MIP-1gamma were not detected. Higher levels of expression were revealed by Northern blot analysis for Mig-1, MCP-1 and C10. The lymphatic endothelium-restricted production of these chemokines was also confirmed by in situ hybridization. The presence of high C10 mRNA expression levels in LEC was particularly unexpected, because the production of this molecule has been previously identified only in cells of the haematopoietic lineage. These observations represent the first detailed analysis of chemokine production by lymphatic endothelial cells and may account, in part, for the mechanism of leucocyte recruitment into the lymphatics, and of lymphocyte recirculation within the lymphatic system.

Increased myocardial apoptosis in patients with unfavorable left ventricular remodeling and early symptomatic post-infarction heart failure

OBJECTIVES

The purpose of this study was to evaluate a potential correlation between apoptotic rate (AR), post-infarction left ventricular (LV) remodeling, and clinical characteristics in subjects who died late (>or=10 days) after an acute myocardial infarction (AMI) with evidence of persistent occlusion of the infarct-related artery at autopsy.

BACKGROUND

Apoptosis contributes to myocardiocyte loss in cardiac disease and may have a pathophysiologic role in post-infarction LV remodeling.

METHODS

The AR was calculated at the site of infarction and in remote unaffected LV regions, using co-localization of in situ end labeling for deoxyribonucleic acid fragmentation and immunohistochemistry for caspase-3, in 14 subjects who died within two months after AMI. Correlation between AR and clinical characteristics such as age, site of AMI, transmural extension, multivessel coronary disease, and signs and/or symptoms of heart failure (HF), at the time of initial hospitalization for AMI or subsequently before death, was assessed using non-parametric statistical tests. Parameters of LV remodeling including diameters, free wall thickness, diameter-to-wall-thickness ratio, and mass were measured at gross examination at autopsy. Values are expressed as median (interquartile range).

RESULTS

Among clinical variables, early symptomatic post-infarction HF (9 cases, 64%) was associated with nearly fourfold increased AR at the site of infarction (26.2% [24.5% to 28.8%] vs. 6.4% [1.9% to 13.3%], p = 0.001). Moreover, AR both at the site of infarction and in unaffected regions was significantly correlated with parameters of progressive LV remodeling (p < 0.05).

CONCLUSIONS

Our data show that in patients dying >or=10 days after AMI, myocardial apoptosis is strongly associated with and may be a major determinant of unfavorable LV remodeling and early symptomatic post-infarction HF.

Hemodynamic effects of a prostacyclin analog (iloprost) on portal flow velocity and volume and visceral artery circulation in patients with lower limb arteriopathy

Previous studies demonstrated that iloprost improves the peripheral circulation. In this study, we examined, by Doppler sonography, portal flow velocity (cm/s) and volume (mL/min), and resistance index (RI) of visceral arteries in 23 patients before and after 7 days of iloprost infusion. Statistically significant hemodynamic changes were only seen in portal vein (pre-iloprost vs. post-iloprost treatment mean portal flow velocity and volume values: 23.9 cm/s vs. 29.0 cm/s, p < 0.001 and 1824.6 mL/min vs. 2294.4 mL/min, p < 0.001, respectively). On the other hand, the interlobar renal artery RI, reduced after iloprost treatment in most patients, was not statistically significant; conflicting results were obtained on the hepatic and mesenteric arteries. Our results indicate that iloprost significantly increases portal flow velocity and volume. The understanding of the mechanism through which iloprost plays a role in portal microcirculation could be useful for its new medical indications in liver hemodynamic disorders.

Enhanced portal flow velocity and volume following Iloprost treatment

OBJECTIVE

We studied, with color Doppler sonography, portal flow velocity (PV) and volume (PFV) before and after Iloprost infusion.

BACKGROUND

Iloprost is a prostacyclin analogue with arterial vasodilator and platelet aggregation inhibitor properties. Recently, hemodynamic effects after treatment with Iloprost have been demonstrated in subjects with arteriopathy of lower limbs.

METHODS

We treated 10 subjects (2 males and 8 females; mean age 64 +/- 8.2 years) affected by arteriopathy of lower limbs with intravenous infusion of Iloprost, at a dosage of 2 ng/Kg/min (16 hours/day) for 3 days. In all patients portal vein flow velocity (PV) (cm/s) and volume (PFV) (ml/min) were assessed. PV was directly determined by the Doppler system, whereas PFV was calculated using the formula "CSA x PV", after measuring the portal vein cross sectional area (CSA) (mm2).

RESULTS

The patients showed markedly increased PV and PFV after Iloprost infusion (pre-Iloprost vs post-Iloprost treatment mean portal flow velocity and volume values: 23.12 +/- 3.89 cm/s vs 28.49 +/- 3.90 cm/s, p < 0.01 and 1743.9 +/- 241.7 ml/min vs 2271.7 +/- 333.5 ml/min, p < 0.001, respectively).

CONCLUSIONS

This study confirms our previous results about increased PV and PFV values after Iloprost treatment. In the light of these results we suggest some possible therapeutic implications in patients undergoing liver transplantation. However, further studies are necessary to confirm this hypothesis.

Interleukin-1 receptor antagonist: a sensitive marker of instability in patients with coronary artery disease

BACKGROUND

Increased plasma levels of acute phase reactants are correlated with acute coronary syndromes and increased risk of in-hospital events. Interleukin-1 receptor antagonist (IL-1Ra) modulates the activity of IL-1, a cytokine associated with inflammatory response; we have prospectively investigated whether detection of increased levels of IL-1Ra in patients may be useful in the characterization of coronary syndromes.

METHODS

Plasma levels of IL-1Ra were measured in 118 consecutive patients undergoing coronary angiography with a clinical diagnosis of recent unstable angina (N = 57), chronic stable angina (N = 49) or atypical chest pain (N = 12).

RESULTS

Angiography showed significant coronary disease in the first two groups and was normal in the latter group. Patients with unstable angina had significantly higher levels of IL-1Ra than stable patients [158 (110-224) vs 108 (95-154) pg/ml, P = 0.002] and individuals with chest pain and normal coronary angiogram [110 (97-123) pg/ml, P: = 0.038]. In contrast, while C-reactive protein levels were significantly higher in patients with stable and unstable angina vs those without coronary disease (0.29 vs 0.06 mg/dl, P: = 0.022), they did not discriminate between stable and unstable angina patients (0.22 vs 0.32 mg/dl, P: = 0.66).

CONCLUSIONS

These results indicate that IL-1Ra may be a sensitive marker of clinical instability in patients with coronary artery disease.

Inflammatory markers and coronary interventions: a potentially useful follow-up modality after stenting

Periprocedural levels of various inflammatory markers have been correlated with prognosis in patients undergoing percutaneous coronary interventions. However, long-term variations of interleukin-1 receptor antagonist (IL-1Ra) or C-reactive protein (CRP) during follow-up after coronary interventions were not previously investigated. The aim of our study was to perform serial evaluations of these markers before and after coronary stenting and to correlate them with clinical status. Plasma levels of IL-1Ra and CRP were measured at baseline and 3 and 6 months after the procedure in 31 patients with symptomatic coronary artery disease undergoing stent implantation, who had no evidence of myocardial ischemia at 6-month follow-up. While at 3 months there were no significant variations of baseline values, 6 months after the procedure a significant decrease from baseline was observed both in IL-1Ra and CRP levels (median -24 pg/ml, P = 0.048, and -0.13 mg/dl, P = 0.017, respectively). Six-month reduction in both IL-1Ra and CRP levels was significant in patients with unstable angina (n = 18; IL-1Ra: from 175 to 119 pg/ml, P = 0.001; CRP: from 0.52 to 0.18 mg/dl, P = 0.002) and nonsignificant in those with stable angina (n = 13) on admission (IL-1Ra: from 123 to 158 pg/ml, P = 0.22; CRP: from 0.19 to 0.10 mg/dl, P = 0.44). In conclusion, a significant reduction of IL-1Ra and CRP levels is observed 6 months after stent implantation in patients with preprocedural unstable angina who remain free of ischemia. This decrease suggests a stabilization of the inflammatory process and may be associated with a favorable prognosis after coronary interventions.

Prognostic value of interleukin-1 receptor antagonist in patients undergoing percutaneous coronary intervention

Elevated plasma levels of inflammatory markers, such as C-reactive protein (CRP), have been associated with adverse outcome in selected patients with coronary artery disease (CAD) treated with coronary angioplasty or stenting. The aim of this study was to evaluate the predictive value of preprocedural interleukin-1 receptor antagonist (IL-1Ra) plasma levels for long-term major adverse cardiac events (MACE) in a series of unselected patients with symptomatic CAD treated with percutaneous coronary intervention (PCI). Seventy-three consecutive patients (62 men, aged 62 +/- 9 years) undergoing PCI were enrolled in a prospective follow-up study. IL-1Ra and CRP plasma levels were measured before the procedure; 36 patients (49%) had unstable angina pectoris on admission, 37 (51%) had chronic stable angina pectoris, and 30 (41%) had multivessel CAD, 15 of whom underwent multivessel PCI. Success was achieved in all 73 patients, with coronary stenting performed in 63 (86%). Follow-up clinical assessment included occurrence of MACE at 3, 6, 12, and 18 months. Logistic regression analysis, performed to determine independent predictors of MACE, identified IL-1Ra levels in the upper quartile as the only independent predictive factor of MACE at 18 months (19% in the fourth quartile vs 0% in the first quartile; p = 0.032). Patients with high preprocedural CRP levels (fourth quartile) had a nonsignificant increased risk of MACE (p = 0.09). Thus, preprocedural IL-1Ra plasma levels appear to be a valuable independent predictive factor of MACE in unselected patients undergoing PCI.

Apoptosis and post-infarction left ventricular remodeling

Apoptosis is a common pathological feature in acute myocardial infarction (AMI), however, its role in the later phases (>10 days) of AMI and in post-infarction left ventricular remodeling has not been characterized. The aim of the study was to identify signs of ongoing cell apoptosis late post AMI. Sixteen hearts were collected at autopsy from subjects 12 to 62 days after the onset of AMI. In situ end-labeling of DNA fragmentation (TUNEL) and co-staining with caspase-3 were performed. Double-positive cells were defined as apoptotic and the apoptotic rate was calculated. Values are expressed as median and interquartile range. Co-stainings with muscle-actin, splicing factor (SC35), PCNA, bax and bcl-2 were also performed. Apoptotic rates at site of infarction [25.4% (17.0-28.4%)] were significantly higher v those at remote regions [0.7% (0.5-0.8%) P<0.001] and significantly correlated to left ventricular longitudinal and transverse diameters [ r = +0.70 (P=0.016) and r = +0.63 (P=0.004) respectively]. Moreover, in subjects with persistently occluded infarct-related artery (14 cases) there was a significantly higher apoptotic rate at the site of infarction compared to those (2 cases) with patent artery [26.0% (21.9-28.5%) v 4.5% (0.6% and 8,4%);P=0.033]. A significantly greater bax immuno-reactivity close to the infarction v remote areas was found (P<0.001). High grade apoptosis is present at sites of infarction in the later phases post AMI. This is more evident if the infarct-related artery is persistently occluded and signs of ventricular remodeling are present. These data may provide an explanation of progressive late left ventricular dysfunction.

Cytolytically inactive terminal complement complex causes transendothelial migration of polymorphonuclear leukocytes in vitro and in vivo

Intravital microscopy was used to monitor leukocyte traffic across rat mesenteric postcapillary venules induced by the inactive terminal complement (C) complex (iTCC) topically applied to ileal mesentery. Leukocytes started rolling within 15 minutes from the administration of iTCC, and by 1 hour they adhered almost completely to the endothelium emigrating from the vessels in the next 3 hours. C5a caused a similar, though less marked, effect, whereas boiled iTCC was inactive, excluding the contribution of contaminating lipopolysaccharide. The complex stimulated the migration of polymorphonuclear neutrophils (PMNs) across endothelial cells (ECs) in a transwell system after a 4-hour incubation of ECs with iTCC added to the lower chamber of the transwell, whereas a 30-minute incubation was sufficient for C5a and interleukin (IL)-8 to induce the passage of PMNs. C5a was not responsible for the effect of iTCC because this complex had no chemotactic activity and contained too small an amount of C5a to account for the transendothelial migration of PMNs. Similarly, the effect of iTCC was not mediated by IL-8 released by stimulated ECs because anti-IL-8 failed to inhibit the migration of PMNs induced by the complex. Unlike tumor necrosis factor-alpha, iTCC did not cause the redistribution of platelet-endothelial cell adhesion molecule-1 (PECAM-1), and PMN mobilization was partially blocked by anti-PECAM-1 antibodies.

Interaction between chronically HIV-infected promonocytic cells and human umbilical vein endothelial cells: role of proinflammatory cytokines and chemokines in viral expression modulation

HIV type 1 expression was significantly up-regulated in chronically infected promonocytic cell line (U1) co-cultured with human umbilical vein endothelial cells (HUVEC). Virus replication, evaluated as supernatant p24 release, was higher when U1 were co-cultured with IL-1beta-activated HUVEC than with unstimulated HUVEC. When non-adherent U1 were removed from co-cultures, the remaining U1 cells adherent to the endothelial monolayer still showed enhanced HIV replication in comparison with an equal number of U1 cultured alone. While addition of adhesion molecule blocking antibodies (anti-intercellular adhesion molecule-1 (ICAM-1), -vascular cell adhesion molecule-1 (VCAM-1), -CD18 and -very late antigen-4 (VLA-4)) strongly inhibited adherence of U1 cells to endothelial monolayers, such treatment resulted in only a partial reduction in p24 release. Furthermore, HIV replication in U1 cells was enhanced on culture in HUVEC-conditioned media. Such data suggest that soluble mediators secreted by endothelial monolayers may modulate HIV-1 expression. Indeed, addition of cytokine and chemokine antagonists to both U1/HUVEC co-cultures and to U1 cultured in HUVEC-conditioned media clearly down-regulated p24 release. Anti-IL-6, anti-tumour necrosis factor-alpha (TNF-alpha) and, particularly, anti-MCP-1 MoAbs reduced p24 release, while anti-IL-8 polyclonal antiserum and IL-1 receptor antagonist (IL-1Ra) had no significant effect. Thus, the interaction between HUVEC and infected monocytic cells up-regulates HIV-1 replication predominantly through production of endothelium-derived soluble factors including MCP-1, TNF-alpha and IL-6. This phenomenon may influence the passage of HIV-1 from latency to productive replication and enhance virus spreading during physiological and/or pathological contact of monocytes with endothelium.

Atherosclerosis and inflammation. Patterns of cytokine regulation in patients with peripheral arterial disease

Inflammatory phenomena at sites of atherosclerotic plaques are increasingly thought to be major determinants of the progression and clinical outcome of atherosclerotic disease. Therefore, attention is being paid to systemic markers/mediators which may reflect the inflammatory activity in the plaques. This study evaluates the pattern of the main proinflammatory cytokines tumor necrosis factor-alpha (TNFalpha), interleukin-1beta (IL-1beta), and interleukin-6 (IL-6), their soluble receptors/antagonist, and a variety of inflammatory markers, in patients with peripheral arterial disease (PAD). Eight patients with PAD suffering from claudicatio intermittens (CI), eight with critical limb ischemia (CLI) and eight controls (C) were studied. Blood samples were collected at baseline in all groups and. for C and CI, immediately after and 4 h after a 30-min treadmill test. Baseline: no differences in cytokine plasma levels were detected among the three groups. In contrast, soluble receptors of TNF (type I and II) and of IL-6, and IL-1beta receptor antagonist (IL-1ra) were increased in CI and CLI patients, as compared to C. Of note, IL-Ira correlated with the occurrence and stage of the disease in a highly significant proportion of the patients, reaching a predictive value for the disease of P < 0.0001. The opposite trend was observed for the soluble receptor of IL-1beta. Notably, in the patients no alterations could be found in white blood cell counts, expression of CD11c adherence molecule by circulating monocytes or, in vitro. O2- release from zymosan-activated neutrophils. Moreover, plasma levels of platelet activating factor (PAF), of neutrophil elastase and of the acute phase reactants C-reactive protein (CRP) and alpha1-acid glycoprotein were not found to be significantly altered. In contrast, the acute-phase proteins alpha1-antitrypsin (alpha1AT) and haptoglobin (HG) were found to be increased. Effect of treadmill: IL-1beta and TNFalpha remained at baseline levels following exercise, and IL-6 dropped to undetectable levels. Among cytokine antagonists, again the most relevant changes concerned the IL-1ra, which was significantly increased immediately after the treadmill test, both in CI and C, and returned to baseline levels after 4 h. In contrast, soluble TNFalpha, IL-1beta and IL-6 receptors, PAF, and the other markers of leukocyte activation were not found to be altered. Soluble TNFalpha and IL-6 receptors were shown to inhibit the biological effects of their ligands. Similarly, IL-1ra and the acute phase proteins alpha1AT and HG have been reported to exert anti-inflammatory functions. The increased plasma levels of these agents, together with low levels of inflammatory cytokines and other pro-inflammatory mediators such as PAF and alpha1-acid glycoprotein, appear to draw an undescribed picture, so far, of upregulation of a composite systemic anti-inflammatory mechanism in atherosclerotic patients. IL-1ra appears to be a reliable marker of the state of activation of this mechanism. These results may provide a basis for developing new insights into the pathogenesis of the atherosclerotic disease.

Complement-endothelial cell interactions: pathophysiological implications

The function of the endothelial cells can be modulated by humoral factors present in the circulation and in the extravascular fluid, including proteins of the complement system. This review examines the multiple interactions between the complement system and the endothelial cells and their functional consequences on inflammation, coagulation and regulation of vascular tone. The implications of these interactions in the induction and progression of the vascular lesions occurring in atherosclerosis, ischemia/reperfusion and xenotransplantation and the possible therapeutic approaches in terms of complement regulation are also discussed.

Endothelial cell E- and P-selectin and vascular cell adhesion molecule-1 function as signaling receptors

Previous studies have shown that polymorphonuclear leukocyte (PMN) adherence to endothelial cells (EC) induces transient increases in EC cytosolic free calcium concentration ([Ca2+]i) that are required for PMN transit across the EC barrier (Huang, A.J., J.E. Manning, T. M. Bandak, M.C. Ratau, K.R. Hanser, and S.C. Silverstein. 1993. J. Cell Biol. 120:1371-1380). To determine whether stimulation of [Ca2+]i changes in EC by leukocytes was induced by the same molecules that mediate leukocyte adherence to EC, [Ca2+]i was measured in Fura2-loaded human EC monolayers. Expression of adhesion molecules by EC was induced by a pretreatment of the cells with histamine or with Escherichia coli lipopolysaccharide (LPS), and [Ca2+]i was measured in single EC after the addition of mAbs directed against the EC adhesion proteins P-selectin, E-selectin, intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), or platelet/endothelial cell adhesion molecule-1 (PECAM-1). Both anti-P- and anti-E-selectin mAb, as well as anti-VCAM-1 mAb, induced transient increases in EC [Ca2+]i that were comparable to those induced by 200 microM histamine. In contrast, no effect was obtained by mAbs directed against the endothelial ICAM-1 or PECAM-1. PMN adherence directly stimulated increases in [Ca2+]i in histamine- or LPS-treated EC. mAbs directed against leukocyte CD18 or PECAM-1, the leukocyte counter-receptors for endothelial ICAM-1 and PECAM-1, respectively, did not inhibit PMN-induced EC activation. In contrast, mAb directed against sialyl Lewis x (sLex), a PMN ligand for endothelial P- and E-selectin, completely inhibited EC stimulation by adherent PMN. Changes in EC [Ca2+]i were also observed after adherence of peripheral blood monocytes to EC treated with LPS for 5 or 24 h. In these experiments, the combined addition of mAbs to sLex and VLA-4, the leukocyte counter-receptor for endothelial VCAM-1, inhibited [Ca2+]i changes in the 5 h-treated EC, whereas the anti-VLA-4 mAb alone was sufficient to inhibit [Ca2+]i changes in the 24 h-treated EC. Again, no inhibitory effect was observed with an anti-CD18 or anti-PECAM-1 mAb. Of note, the conditions that induced changes in EC [Ca2+]i, i.e. , mAbs directed against endothelial selectins or VCAM-1, and PMN or monocyte adhesion to EC via selectins or VCAM-1, but not via ICAM-1 or PECAM-1, also induced a rearrangement of EC cytoskeletal microfilaments from a circumferential ring to stress fibers. We conclude that, in addition to their role as adhesion receptors, endothelial selectins and VCAM-1 mediate endothelial stimulation by adhering leukocytes.

The cytolytically inactive terminal complement complex activates endothelial cells to express adhesion molecules and tissue factor procoagulant activity

The membrane attack complex of complement (C) in sublytic concentrations stimulates endothelial cells (EC) to express adhesion molecules and to release biologically active products. We have examined the ability of a cytolytically inactive form of this complex, which is incapable of inserting into the cell membrane, to upregulate the expression of adhesion molecules and of tissue factor (TF) procoagulant activity. The inactive terminal C complex (iTCC) was prepared by mixing C5b6, C7, C8, and C9 and was purified by fast protein liquid chromatography on a Superose 12 column. Binding of this complex to EC was found to be dose dependent and was inhibited by anti-C9 antibodies, as assessed both by ELISA using an mAb anti-C9 neoantigen and by measuring cell-bound 125I-labeled iTCC. Exposure of EC to iTCC resulted in a dose- and time-dependent expression of endothelial leukocyte adhesion molecule 1, intercellular adhesion molecule 1, and vascular cell adhesion molecule 1 accompanied by increased levels of the corresponding mRNA, but not in the rapid expression of P-selectin. Inactive TCC also induced increased TF activity evaluated by a chromogenic assay that measures the formation of factor Xa. These effects were inhibited by anti-C9 antibodies. The data support the conclusion that iTCC may induce proinflammatory and procoagulant activities on EC.

Leptospira interrogans and Leptospira peptidoglycans induce the release of tumor necrosis factor alpha from human monocytes

Elevated plasma concentrations of the cytokine tumor necrosis factor alpha (TNF alpha) have been observed in patients affected by leptospirosis. In this study we found that a preparation of peptidoglycan of Leptospira interrogans, serovar copenhageni, was able to induce the release of TNF alpha from peripheral blood mononuclear cells. TNF alpha induction occurred in a dose dependent manner and was not affected by the endotoxin inhibitor polymixin B. This is the first report on induction of TNF alpha release by a peptidoglycan of spirochetes. Our findings are consistent with existing clinical data and provide a potential mechanism for TNF alpha production.

Leptospira icterohemorrhagiae and leptospire peptidolgycans induce endothelial cell adhesiveness for polymorphonuclear leukocytes

We have examined the effect of the virulent Leptospira interrogans strain Teramo, serotype icterohemorrhagiae, on the adherence of human neutrophilic polymorphonuclear leukocytes (PMN) to cultured human umbilical vein endothelial cells (HEC). Selective pretreatment of HEC with intact or sonicated leptospires caused a dose- and time-dependent increase of HEC-PMN adhesion (13.2% +/- 2.5% adherence to untreated HEC versus 46.3% +/- 5.6% adherence to HEC pretreated for 4 h with 10(8) intact leptospires per ml [mean +/- standard error of six experiments; P < 0.001]). In contrast, selective leptospire pretreatment of PMN or the addition of leptospires during the adherence assay did not alter HEC-PMN adherence. Leptospire induction of endothelial-cell adhesiveness occurred without detectable HEC damage and was prevented by RNA and protein synthesis inhibitors and by monoclonal antibodies to the CD11/CD18 adhesion complex of neutrophils and to the endothelial-leukocyte adhesion molecule 1 (ELAM-1) of endothelial cells. Similar results were obtained with pretreatment of HEC with interleukin-1 or with the lipopolysaccharide (LPS) of the gram-negative bacterium Escherichia coli. The possibility that contamination by the LPS of gram-negative bacteria could be involved in the induction of HEC adhesiveness was ruled out by the observation that the LPS inhibitor polymyxin B, which abolished the proadhesive effect of E. coli LPS, was ineffective in inhibiting leptospire- as well as interleukin-1-induced adherence. Similarly, leptospire LPSs seemed to have no role in the increase of endothelial-cell adhesiveness, since pretreatment of HEC with a leptospire LPS extract (phenol-water method) or with a leptospire total lipid extract failed to induce the proadhesive phenotype for neutrophils. Instead, peptidoglycans extracted from our leptospires actively stimulated the endothelial proadhesive activity for neutrophils (16.5% +/- 2.1% adherence to untreated HEC versus 51.2% +/- 2.9% adherence to HEC pretreated for 4 h with 1 microgram of peptidoglycan per ml; [mean +/- standard error of four experiments; P < 0.001]). This peptidoglycan-induced activity was inhibited by monoclonal antibodies to the CD11/CD18 adhesion complex and to ELAM-1 but not by polymyxin B. We conclude that peptidoglycans from pathogenic leptospires are among the molecules that can directly activate vascular endothelial cells to increase their adhesiveness for neutrophilic granulocytes. These observations may contribute to a better understanding of the mechanisms whereby non-gram-negative bacteria modulate the local and systemic inflammatory reaction.

Biological activity of a peptidoglycan extracted from Leptospira interrogans: in vitro studies

Peptidoglycan (PG) has been isolated from some species of spirochaetes, including Leptospira interrogans. Although leptospiral PG has been chemically characterized, no study has been carried out on its potential biological activity. Since PG of Treponema and Borrelia is biologically active both in vivo and in vitro, we investigated the capacity of a leptospiral PG preparation to induce relevant biological effects. PG extracted from L. interrogans strain Teramo was mitogenic at 0.1 microgram ml-1 for human peripheral blood mononuclear cells (PBMC) since it increased the PBMC fraction positive for Ki-67, an antigen expressed by human proliferating cells; at 4 micrograms ml-1, PG was able to induce complement consumption and to stimulate leucocyte phagocytosis and the metabolic burst of resting as well as phagocytosing leucocytes. These findings indicate that Leptospira PG may play a role in modulating the immunocompetent cell functions and suggest that PG can contribute to the host response during Leptospira infection.

Effects of endotoxin in mice bearing solid metastasizing tumors and treated with lysozyme hydrochloride

The effects of the i.v. administration of endotoxin (6.25-50 micrograms/mouse on day 13 after tumor implantation) in mice treated orally with lysozyme hydrochloride (100 mg/kg on days 5-12 from tumor implantation) were examined using Lewis lung carcinoma in the C57Bl mouse and MCa mammary carcinoma of CBA mice. On primary tumor growth, endotoxin alone causes a dose-dependent and statistically significant reduction with a nadir on day +2 from endotoxin treatment. Combined with lysozyme, endotoxin causes an effect independent of the dose used, corresponding to the effect caused by endotoxin alone at the dose of 25 micrograms/mouse. No tumor regression was recorded in any of the treated groups. Endotoxin is virtually devoid of effects at the metastatic level. In the same conditions, lysozyme causes a reduction of primary tumor growth and a more pronounced inhibition of lung metastasis formation as expected from its already reported effects. The antitumor activity of endotoxin, unlike lysozyme, can be ascribed to tumor hemorrhagic necrosis due to tumor necrosis factor (TNF) production, as determined in tumor homogenates. Endotoxin does not increase the antitumor effects in mice treated with lysozyme, as expected from the data obtained with the more immunogenic SA1 sarcoma, although lysozyme increased the mitogenic response to ConA of ex vivo isolated splenocytes, in vitro cultured in the presence of IL-2.