Bosentan treatment for Raynauds phenomenon and skin fibrosis in patients with Systemic Sclerosis and pulmonary arterial hypertension: an open-label, observational, retrospective study.

Raynaud?s phenomenon (RP) and cutaneous fibrosis are the distinctive manifestations of scleroderma, in which Endothelin-1 plays a fundamental pathogenetic role. Bosentan, an Endothelin-1 receptor antagonist used for the treatment of pulmonary arterial hypertension, retards the beginning of new sclerodermic digital ulcers (DU). This open-label, observational, retrospective study verified the effect of Bosentan on RP and skin fibrosis in sclerodermic outpatients affected by pulmonary arterial hypertension without DU. Fourteen subjects (13 women, 1 man; mean age 60 ± 7.5 years; ten with limited and four with diffuse scleroderma) were observed at baseline (T0) and after four (T1), twelve (T2), twenty-four (T3) and forty-eight (T4) weeks during treatment with Bosentan. They were evaluated for daily quantity and duration of RP attacks and skin thickness (using modified Rodnan total skin score, MRSS). Videocapillaroscopic evaluation was performed at T0 and T4. Bosentan decreased significantly the number and duration of RP attacks, beginning at T2 (p<0.05). Videocapillaroscopy showed significant improvement of microcirculatory patterns at T4 (p<0.05). MRSS decreased throughout the study, reaching the statistical significance at T3 and T4 (p<0.01) in the whole cohort. The present data suggest that Bosentan is effective in stabilizing the microcirculation involvement and in improving skin fibrosis irrespective of scleroderma patterns.

Refractory Takayasu arteritis successfully treated with infliximab.

Takayasu arteritis (TA) is a chronic inflammatory disease of large arteries which progressively develop stenosis, occlusion or aneurismal degeneration. Proinflammatory cytokines and, among these, tumor necrosis factor-alpha (TNF-alpha) are increased and play a pathogenetic role in the development of disease. Conventional therapy often fails to determine clinical remission and, in these cases, pathogenetic strategies with anti-TNF-alpha drugs have been proposed. Infliximab is a human-murine chimeric monoclonal antibody that specifically binds to and neutralizes soluble TNF-alpha. It is an effective treatment for rheumatoid arthritis, spondyloarthritis, Crohn's disease and ulcerative colitis and it has been recently proposed for the treatment of TA in patients refractory to conventional therapy. Here we report the case of a patient affected by Takayasu arteritis unresponsive to conventional therapy who was then treated with infliximab and obtained a clinical remission of the disease.

Extracorporeal photopheresis affects co-stimulatory molecule expression and interleukin-10 production by dendritic cells in graft-versus-host disease patients.

Graft-versus-host disease (GVHD) is a major complication of allogeneic bone marrow transplantation. Extracorporeal photochemotherapy (ECP) has been introduced as an alternative treatment for GVHD refractory to conventional immunosuppressive treatment, although its mechanism of action is not yet clear. We investigated, in seven GVHD patients, the effects of ECP on dendritic cell maturation and cytokine production in an in vitro model that could mimic the potential in vivo effect of reinfusion of ECP-treated peripheral blood mononuclear cells. The model was based on co-culture of ECP-treated lymphocytes with monocyte-derived dendritic cells (DCs) of the same patient. We found that the co-culture of ECP-treated lymphocytes with immature DCs reduced CD54, CD40 and CD86 mean fluorescence intensity (MFI) significantly after lipopolysaccharide (LPS) stimulation, without affecting human leucocyte antigen D-related and CD80 MFI. In the same co-culture model, DCs produced increased amounts of interleukin (IL)-10 when co-cultured with ECP-treated lymphocytes and stimulated with LPS, while IL-12 and tumour necrosis factor-alpha production were not affected. These results suggest that reinfusion of large numbers of autologous apoptotic lymphocytes is significant for the therapeutic outcome of ECP through down-regulation of co-stimulatory molecules on DCs, inducing non-fully mature DCs with a low signal 2 and up-regulation of IL-10, which is an immunosuppressive cytokine.

Genetic influence in antithrombotic actions of atorvastatin in hypercholesterolaemia.

BACKGROUND: Recent data indicate that statins could offer coronary artery disease (CAD) benefit even by mechanisms beyond lipid lowering. Genetic influence has been shown for some antithrombotic actions of statins via oxidized-low-density lipoprotein cholesterol (ox-LDL) receptors and nitric oxide synthase (NOS) activity modulation. The present study was designed to evaluate the influence of ox-LDL lectin-like receptor-1 (LOX-1) and NOS polymorphisms in the incidence of cardiovascular events in pure hypercholesterolaemic subjects during statin treatment. MATERIALS AND METHODS: A prospective 4-year study involving 1039 event-free subjects (643 males, 396 females) treated with atorvastatin (10-40 mg day(-1)) to reach the appropriate Adult Treatment Panel-III LDL target of 3.36 mmol L(-1). Enrolled subjects were evaluated every 6 months or at a clinical event. LOX-1 3'UTR/T-C and NOS G894T polymorphisms were detected by allelic discrimination assays (polymerase chain reaction), lipid profile by enzymatic-colorimetric method, ox-LDL by enzyme linked immunosorbent assay, platelet activation by P-selectin (P-sel) expression (FACScan), NOS activity (by intracellular citrullin recovery) and homocysteine (high performance liquid chromatography), C-reactive protein (CRP) by sensitive nephelometric technique. RESULTS: LOX-1 3'UTR/T showed the strongest association with events in the whole cohort with respect to each other variable including LDL reduction and NOS G894T (OR 4.90, 95% CI 3.19-6.98, P < 0.00001). Smoking influenced events in LDL-targeted subjects (P < 0.0001). Ox-LDL and P-sel were better indicators than LDL or other variables according to 3'UTR/C genotype regardless of the magnitude of LDL reduction (OR 4.21, 95% CI 2.29-6.70 P < 0.0001). CONCLUSIONS: LOX-1 polymorphisms could influence statin effectiveness in CAD prevention by induction of sensitivity to antithrombotic mechanisms such as antiplatelet activity.

Myelodysplasia and Good syndrome. A case report.

Good syndrome (GS) is a rare adult-onset immunodeficiency disease characterised by hypogammaglobulinaemia and thymoma. Here we describe a 72-year-old male patient who was diagnosed with GS when he was 62, after a two-year history of recurrent respiratory infections. A chest CT scan showed a mediastinal mass which was surgically removed; its histology revealed a thymoma. The patient was hypogammaglobulinaemic and his clinical condition dramatically improved after starting an appropriate dosage of IVIG. Two years ago he developed a normochromic normocytic anaemia requiring several transfusions. A bone marrow biopsy revealed a myelodysplastic syndrome. The patient started cyclosporine and the anaemia gradually improved, achieving transfusion independence.

Inhibition of maturation of human monocyte-derived dendritic cells in a patient with Mycobacterium avium infection.

Mycobacterium avium complex is a facultative intracellular pathogen that can cause pulmonary disease in immunocompromised individuals. Dendritic cells (DCs) play a central role in protective immunity against mycobacteria. Mycobacterium avium complex infects DCs but does not impair in vitro infected monocytes differentiation into DCs. A 54-year old woman affected by chronic graft-versus-host-disease (cGVHD) was referred to our Division of Dermatology. Immature DCs were generated from her monocytes. One week later she was hospitalized due to a lung infection with Mycobacterium avium complex. Monocyte-derived DCs during Mycobacterium avium infection expressed low levels of CD1a and CD80 as determined by flow cytometry. They also expressed high levels of CD83 and CD86, and when stimulated with LPS for 24 hrs they slightly up-regulated CD83 and did not produce IL12. When monocyte-derived DCs were obtained from the patient after having recovered from the Mycobacterium avium complex infection, they expressed normal levels of CD1a and CD80 and were negative both for CD83 and for CD86. IL12 production in response to LPS was restored. Inhibition of DC maturation by the in vivo infection with Mycobacterium avium may be an immune-evasion mechanism used by the pathogen because incompletely matured DCs may not activate effector T cells efficiently in vivo.

Pro-inflammatory/anti-inflammatory cytokine imbalance in acute coronary syndromes.

The aim of this study was to evaluate the presence of an imbalance between proinflammatory and anti-inflammatory mediators in patients affected by acute coronary syndromes (ACS). We considered two groups of 26 and 28 patients with acute myocardial infarction (AMI) and unstable angina (UA) respectively, compared with a group of 30 patients with stable angina and 30 healthy volunteers. We evaluated the production in cultured and stimulated lymphomonocytes of interferon (IFN)gamma and tumour necrosis factor (TNF)alpha, which are well known to possess proinflammatory effects, and of interleukin (IL)10, which has been shown to have a protective anti-inflammatory activity. We also assessed the clinical characteristics of groups and, particularly, we evaluated the circulating levels of C-reactive protein (hs-CRP). We found a significant increase of IFNgamma and TNFalpha production (P<0.01) and a significant decrease of IL10 production (P<0.05) in cultures of lymphomonocytes taken from patients with AMI and UA compared with SA patients and controls. No significant changes where found between AMI and UA patients and SA patients and controls. Circulating levels of hs-CRP were significantly increased (P<0.01) in patients with ACS compared with the other control groups. Our data showed an increased production of proinflammatory mediators in ACS that may be detectable both in circulating blood and in cell cultures where it is possible to evaluate in a better way the functional state of cells; this finding was associated with a reduced production of the antiinflammatory cytokine IL10. In conclusion, a relevant imbalance is present in ACS and this fact could contribute to plaque instability and clinical manifestations.

Iloprost treatment reduces TNF-alpha production and TNF-RII expression in critical limb ischemia patients without affecting IL6.

Iloprost, a stable prostacyclin analogue, regulates expression of genes that are involved in inflammation and in cell growth and inhibits the in vitro production of cytokines. We evaluated the effect of an in vivo weekly iloprost treatment on TNF-alpha and IL6 monocyte production (evaluated by ELISA), on monocyte apoptosis (Annexin V/uptake of propidium iodide by flow cytometry) and on peripheral blood mononuclear cell (PBMC) TNF-alpha receptors (TNF-RI and TNF-RII) mRNA expression (RT-PCR) in 14 atherosclerotic critical limb ischemia patients. PBMC were stimulated with LPS for 24h. TNF-alpha production was significantly reduced by iloprost whereas IL6 production was not affected. Iloprost did not accelerate monocyte apoptosis. TNF-RI mRNA expression was not modified by iloprost, whereas TNF-RII mRNA expression was significantly reduced. Our data show that iloprost may have anti-inflammatory effects in addition to the well-known vasodilatatory and anti-aggregant ones.

Cytokines in acute coronary syndromes.

The aim of this study was to show the presence of an imbalance between pro-inflammatory and anti-inflammatory mediators in patients affected by acute coronary syndromes (ACS). We evaluated the production in cultured and stimulated lymphomonocytes of interferon (IFN)gamma and tumor necrosis factor (TNF)alpha, which are well known to possess pro-inflammatory effects, and of interleukin (IL)10, which has been shown to have a protective anti-inflammatory activity, in two groups of 30 patients affected by acute myocardial infarction (AMI) and unstable angina (UA), compared with two equivalent groups of patients with stable angina (SA) and of healthy volunteers. We found a significant increase of IFNgamma and TNFalpha production (p<0.01) and a significant decrease of IL-10 production (p<0.01) in cultures of lymphomonocytes taken from patients with AMI and UA compared with SA patients and controls. No significant changes were found between AMI and UA patients and SA patients and controls. We conclude that a relevant imbalance in cytokine release is present in ACS, markedly favoring pro-inflammatory effects.

Adenosine system and cell calcium translocation: interference of calcium channel blockers.

Adenosine is able to inhibit in vitro neutrophil functions induced by formyl-methionyl-leucyl-phenylalanine (FMLP) and A23187, but not phorbol 12-myristate 13-acetate (PMA). The inhibiting activity on A23187 is reversed by increasing extracellular Ca2++ concentration. The calcium entry blocker flunarizine shows an activity very similar to that of adenosine. Both adenosine and flunarizine prevent Ca++ influx into activated neutrophils as detected by the fluorescent Ca++ chelator Quin-2. Finally, flunarizine binds to the neutrophil membrane and adenosine competitively inhibits flunarizine binding as assessed by 1H-Nuclear Magnetic Resonance (1H-NMR) technique, thus indicating that the two agents share a common binding site on the cell membrane.

Effects of carvedilol on left ventricular remodeling and systolic function in elderly patients with heart failure.

BACKGROUND: Recent studies have shown that carvedilol therapy in patients with heart failure improves clinical outcome and survival, however, the effects of such treatment on left cardiac morphology and function in elderly patients with severe heart failure has not been widely studied. AIM: The purpose of this study was to establish the effect of carvedilol at short- and long-term on left ventricular size and performance with mono- and two-dimensional echocardiography, in subjects with dilated cardiomyopathy, NYHA III functional class, low LV ejection fraction (EF < 35%) and mean age of > 70 years. METHODS: We studied 48 patients, previously randomized to treatment with either carvedilol or placebo, and we performed echocardiographic evaluation at the start, and after 3 and 12 months. Left ventricular diameters, LV mass and fractional shortening were calculated by Deveraux formula; left ventricular volumes and ejection fraction were measured by area-length formula; pulmonary pressure was calculated by tricuspid reflow. RESULTS: After 3 months, only LV end-diastolic diameter was lower in the carvedilol group compared to the placebo group. Nevertheless, after 12 months, patients on carvedilol treatment showed a LV geometric and functional improvement compared to placebo. We found significant differences in: diastolic (P < 0.01) and systolic diameters (P < 0.001); on LV mass (P < 0.002); on LV systolic volume (P < 0.03); and on LV ejection fraction (P<0.01). Pulmonary pressure was also reduced in beta-blocker subjects (P < 0.001). CONCLUSIONS: Carvedilol therapy for 12 months reduced LV diameters and volumes. Thus, improving cardiac remodeling and LV systolic function in elderly patients with severe heart failure. Several months of therapy are required for these favorable effects to occur, as these changes do not occur in the short term.

Enhanced apoptosis of peripheral blood mononuclear cells in cardiac transplanted patients undergoing chronic immunosuppressive treatment.

Apoptosis plays a major role in tissue transplantation because intact T-cell-apoptosis pathways are required for the induction of tolerance to allografts. Moreover, immunosuppressive agents commonly used in clinical transplantation medicine promote lymphocyte apoptosis inhibiting the expression and production of cytokines involved in lymphocyte survival. The aim of our study was to evaluate peripheral blood mononuclear cells (PBMC) spontaneous apoptosis in patients undergoing chronic immunosuppressive treatment after cardiac transplantation. PBMC obtained from patients (n = 31) and controls matched for age and sex (n = 25) were cultured for 72 h and apoptosis was evaluated by quantification of fragmented DNA, staining with Hoechst 33258 dye and annexin V binding. We also investigated Fas expression and FasL mRNA expression as well as the ability of an IgM anti-Fas antibody to induce apoptosis. Finally, we evaluated IL2 production induced by PHA and the ability of IL2 to prevent apoptosis. In patients, PBMC underwent enhanced spontaneous apoptosis in comparison with controls. However, we could not find any difference between patients and normals as regards the expression of Fas and of FasL mRNA, even if the cross-linking of the Fas molecule induced apoptosis in PBMC from patients, whereas it failed to induce cell death in normals. We also found that IL2 production was significantly decreased in patients and that the addition of IL2 to the culture medium reduced PBMC spontaneous apoptosis. Our findings suggest that in cardiac transplanted patients PBMC undergo enhanced spontaneous apoptosis, which may contribute to prevent allograft rejection.

Heparin inhibition of polymorphonuclear leukocyte activation in vitro. A possible pharmacological approach to granulocyte-mediated vascular damage.

The "in vitro" effects of heparin on different functions of human polymorphonuclear leukocytes were studied. Granulocyte aggregation, enzyme release induced by FMLP and zymosan-activated serum and superoxide anion and chemiluminescence generated by FMLP were assessed. Heparin (25-500 micrograms/ml) was able to inhibit in a dose-dependent way cellular aggregation and degranulation induced either by FMLP or by zymosan-activated serum. FMLP-dependent superoxide anion generation and chemiluminescence were specifically inhibited by heparin at the concentration of 25 micrograms/ml. Our results showed that heparin "in vitro" inhibits all the aspects of the functional and metabolic granulocyte activation. A possible protecting effect of the drug on leukocyte-mediated tissue injury and vascular damage is discussed.

Nitroprusside in vitro inhibits platelet aggregation and intracellular calcium translocation. Effect of haemoglobin.

The biologically final active compound of nitrovasodilators is now supposed to be nitric oxide (NO), a labile substance identical to EDRF. The effects of nitroprusside on platelet functions were studied in vitro. Platelet aggregation induced by several stimuli (ADP, collagen, arachidonic acid and PAF) was inhibited by increasing concentrations of the drug (1-50 uM); interestingly, the potency of nitroprusside is higher when PAF is employed as stimulating agent in comparison with the other agonists (ED50 = 2 uM for ADP, 2.5 uM for A.A., 4.5 uM for collagen and 0.3 uM for PAF-induced aggregations). The concomitant addition of haemoglobin is able to reverse the inhibitory effect of nitroprusside, according to the view that haemoglobin possesses a high affinity for NO, thus antagonizing the effect of this compound. Nitroprusside was also able to inhibit intracellular calcium translocation, as studied with the Quin 2 technique, induced by PAF and arachidonic acid. Fron these observations the hypothesis may be suggested that nitroprusside inhibits platelet functions by mimicking the endogenous NO, and that the intracellular calcium metabolism is involved in the inhibitory activity of the drug.

ECP-treated lymphocytes of chronic graft-versus-host disease patients undergo apoptosis which involves both the Fas/FasL system and the Bcl-2 protein family.

Chronic graft-versus-host disease (cGVHD) is a severe and frequent complication of allogenic bone marrow transplantation which is often treated with extracorporeal photochemotherapy (ECP) with a positive clinical outcome in patients resistant to conventional protocols. The mechanism of action of ECP has not been fully elucidated, although several authors have reported that it is able to induce apoptosis. Using samples obtained from ten cGVHD patients, we sought to determine whether lymphocytes treated with ECP underwent apoptosis and, above all, the mechanisms involved. Lymphocytes at four stages were isolated: immediately before ECP, from the last buffy coat collected, after UV irradiation prior to reinfusion, and the day after ECP. When cultured for 48 h, lymphocytes treated with ECP underwent accelerated apoptosis (tested as annexin V binding cells and as intracellular histone-associated DNA fragments) in comparison with lymphocytes from the other samples. This enhanced programmed cell death could not be prevented by IL-2. Immediately after isolation, there was no difference in Bcl-2 or bax expression among the four different samples, or in Fas and FasL mRNA. However, when cultured, lymphocytes treated with ECP showed a rapid downregulation of Bcl-2, an upregulation of bax with an increased bax/Bcl-2 ratio, a decrease in bcl-2 mRNA and an increase in Fas. No changes were detectable in lymphocytes from the other samples. IL-2 and TNF-alpha production was not significantly different among lymphocytes from the four samples. In conclusion, in patients affected by cGVHD, ECP induced apoptosis of lymphocytes with the involvement of both the Fas/FasL system and the Bcl-2 protein family.

Effect of atorvastatin on different fibrinolyis mechanisms in hypercholesterolemic subjects.

BACKGROUND: Hydroxymethyl-glutaryl-CoA-reductase inhibitors (statins) reduce cardiovascular events by cholesterol lowering as well as non-lipid related actions. Among them, the modulation of fibrinolysis could play a relevant role in vascular protection. Atorvastatin is able of reducing platelet activity and thrombin generation before low-density lipoprotein cholesterol (LDL-C) decrease in hypercholesterolemic subjects in which coagulation and fibrinolysis are linked by the activation of thrombin activable fibrinolysis inhibitor (TAFI). The aim of our study was to evaluate whether atorvastatin could modulate fibrinolysis by interactions with endothelial mechanisms and thrombin generation. METHODS: Forty-four pure hypercholesterolemic subjects (26 M, 18 F, mean age 52.7+/-13.7, LDL-C 194.8+/-9.3t mg/dl) were evaluated for plasmin-antiplasmin complexes (PAP), tissue-plasminogen acivator (t-PA) and its inhibitor (PAI-1) (ELISA), TAFI activity (HPLC), platelet P-selectin (P-sel) (cytofluorymetric detection), platelet-dependent thrombin generation (PDTG, coagulative-chromogenic method) and lipid profile at baseline and after 7, 14, 28 and 90 days of atorvastatin (10 mg/die) treatment. RESULTS: PAP were significantly reduced at baseline in hypercholesterolemic versus control subjects (P<0.05) and were related to P-sel (P<0.01), PDTG (P<0.01) and its inhibitor (PAI-1) after venous occlusion (VO) (P<0.05). Atorvastatin induced a significant increase of PAP at T(2) related to modifications of P-sel (P<0.01) and PDTG (P<0.01) before significant LDL-C reduction (P=0.132). PAI-1 was significantly changed at T(3) with relation to LDL-C (P<0.01), Von Willebrand factor (VWF) (P<0.01) and sE-sel (P<0.05). CONCLUSIONS: The profibrinolytic activity of atorvastatin in hypercholesterolemic subjects is related, initially, to the positive effects exerted on platelet function and thrombin generation which can modulate fibrinolysis by TAFI activity.

Common variable immunodeficiency: a review.

Common variable immunodeficiency (CVID) is the commonest symptomatic primary antibody deficiency syndrome. The predominant manifestation is hypogammaglobulinemia. CVID is characterized by recurrent bacterial infections, especially of the upper and lower respiratory airways, and is also associated with an increased incidence of autoimmune and neoplastic disorders. Most patients are diagnosed as adults and delay in the recognition of the disease is common. Several T and B cell defects have been described, although the underlying cause is still unknown.

T cell activation and enhanced apoptosis in non-ST elevation myocardial infarction.

Recent studies have shown that inflammation plays a major role in coronary plaque destabilization and in the induction of thrombosis in acute coronary syndromes. The aim of this study was to evaluate circulating lymphocyte activation and apoptosis in patients with non-ST elevation myocardial infarction (NSTEMI) in comparison with subjects with stable angina and with age-matched healthy controls. We considered T cell subpopulations, T cell surface HLA-DR and CD69 expression (evaluated by flow cytometry), lymphomonocyte spontaneous apoptosis (evaluated by ELISA), and IL2 production (evaluated by ELISA) in peripheral blood within 6 hours of onset of NSTEMI. We also investigated Fas expression on T cells (evaluated by flow cytometry) and FasL mRNA (evaluated by RT-PCR), as well as Fas functionality. In NSTEMI patients we found a significant increase of HLADR+ CD3+ and CD69+CD4+ cells. Spontaneous apoptosis was significantly increased in NSTEMI patients in comparison with the two control groups and was associated with an increased expression of Fas, an increased susceptibility to Fas agonist (CH11), and a normal production of IL2 in cell cultures. These data suggest that the enhanced apoptosis is due to a mechanism of "active" antigen-driven death, induced by the expression of death cytokines and not by the failure of cell growth factors. We conclude that peripheral lymphocytes are activated in NSTEMI and undergo an enhanced programmed cell death due to activation mechanisms. It is likely that lymphocyte activation occurs before the onset of acute ischemia and contributes to the plaque rupture and to the myocardial ischemic insult.

Plasma brain natriuretic peptide levels in coronary heart disease with preserved systolic function.

We evaluated the circulating levels of brain natriuretic peptide (BNP) in stable angina, unstable angina, and myocardial infarction relating hormone levels to extension of coronary disease and number of vessels involved after angiographic examination. We studied 86 patients consecutively undergoing angiographic coronary examination and echocardiographic evaluation for coronary heart disease. These included 15 control subjects (group 0), 21 with stable angina (group I), 26 with unstable angina (group II), and 24 with non-Q myocardial infarction (group III). Patients with heart failure, a history of myocardial infarction, or recent myocardial damage with electrocardiographic S-T elevation were excluded. BNP levels in patients with unstable angina and myocardial infarction were significantly increased with respect to the group with stable angina (P<0.01). There were no differences between the groups with unstable angina and myocardial infarction. Analysis of peptide levels in relation to the number of involved vessels demonstrated a significant increase in patients with three-vessel disease compared with subjects with one or two vessels involved (P<0.03); among subjects with mono-vessel disease, patients with left descendent anterior stenosis had a more-marked BNP elevation than subjects with stenosis in other regions (P<0.01). Hence, BNP levels appear to be elevated in coronary disease, especially in acute coronary syndromes, even in the absence of systolic dysfunction. BNP levels also seem to be related to the severity of coronary atherosclerosis and number of vessels involved. BNP could prove a novel marker for risk stratification, not only in heart failure but also in coronary heart disease.

Different effect induced by treatment with several statins on monocyte tissue factor expression in hypercholesterolemic subjects.

Platelets and monocytes are involved in atherothrombosis via tissue factor expression. Moreover, they are activated in hypercholesterolemia, a classic risk factor for atherothrombosis. Cholesterol-lowering drugs (statins) reduce cardiovascular risk either by decreasing cholesterol or non-lipidic actions, such as platelet and monocyte activity. The aim of our study was to evaluate the effect of several statins on platelet and monocyte activity in hypercholesterolemic subjects. Platelet activity (P-selectin, cytofluorimetric detection), tissue factor levels (ELISA) and activity (detected in whole blood and cellular preparations by a specific clotting assay) were measured in hypercholesterolemic subjects (41 males, 23 females, aged 34-65 years, total cholesterol 6.86+/-0.60 mmol/l) treated with atorvastatin 10 mg, simvastatin 20 mg, fluvastatin 40 mg, or pravastatin 40 mg for 6 weeks. P-selectin and tissue factor expression in whole blood and isolated cells were increased in hypercholesterolemic subjects with respect to controls (all P<0.001). Simvastatin, atorvastatin, and fluvastatin reduced monocyte procoagulant activity in whole blood and P-selectin (P<0.01). Tissue factor antigen and activity in isolated cells were further reduced (all P<0.05) independently of cholesterol lowering. Pravastatin decreased tissue factor expression in whole blood in direct relationship to reduction of P-sel and cholesterol (P<0.05). Our data show a different impact of several statins on monocyte tissue factor expression in whole blood, suggesting a possible role of decreased platelet activity and a direct action on monocytes. In contrast, pravastatin decreased monocyte procoagulant activity with relation to cholesteroldependent modifications of platelet function.