Anna Laura Pasqui

Platelet hyperactivity after statin treatment discontinuation

Hydroxymethyl-glutaryl-CoA-reductase inhibitors (statins) reduce cardiovascular events by cholesterol lowering as well as by non-lipid related actions. Among them, the modulation of platelet activity could play a relevant role in vascular protection. Furthermore withdrawal of statins has been associated with increased cardiovascular event rate. The aim of our study was to evaluate platelet activity after cerivastatin discontinuation in eighteen subjects that did not accept other drugs and in sixteen subjects continuing treatment with simvastatin. Fourteen subjects at the end of the discontinuation period decided to receive other drugs (simvastatin) and they were evaluted six weeks later. We measured complete lipid profile by the chromogenic method (LDL-C was calculated); oxidized-LDL (ox-LDL; ELISA), platelet P-selectin (P-sel) expression (flow cytometry detection), platelet aggregation (% change of transmitted light), intracellular citrullin production (iCit; HPLC) as an indicator of intracellular NO synthase activity at baseline and 7, 14, 28, 60 days after statin discontinuation. P-sel expression and platelet aggregation were increased at 14 days (p < 0.001 and p < 0.05) in association with raised ox-LDL (r = 0.30, p < 0.05) and decreased iCit (r = 0.53, p < 0.01). Increased LDL-C was related to P-sel and platelet aggregation at 28 days (r = 0.30, p < 0.05). Subjects continuing statin treatment had no significant changes of P-sel at 28 (p = 0.221) and 60 days (p = 0.238). Subjects treated with simvastatin after 60 days of diet showed a significant reduction of P-sel and platelet aggregation after six weeks of treatment (p < 0.01). Our data suggest a platelet hyperactivation state in the second week after statin discontinuation which is partially related to raised LDL-C. Such a finding could participate in the increased cardiovascular event rate after statin discontinuation.

Erratum to “Pro/Anti-Inflammatory Cytokine Imbalance in Postischemic Left Ventricular Remodeling”

The authors would like to inform the correct names for the present paper as stated above.

Takayasu's arteritis: a review of the literature.

Takayasus arteritis is a rare, idiopathic, chronic inflammatory disease with cell-mediated inflammation, involving mainly the aorta and its major branches. It leads to stenosis, occlusion or aneurysmal degeneration of large arteries. The clinical presentation is characterised by an acute phase with constitutional symptoms, followed, months or years later, by a chronic phase in which symptoms relate to fibrosis or occlusion of vessels. Angiography is the gold standard for diagnosis and for topographical classification and it correlates with symptoms and prognosis. Here we focus on the pathophysiology, clinical and angiographical classification, diagnostic assessment and therapeutic approach of Takayasus arteritis.

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)γ and tumour necrosis factor (TNF)α, 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 IFNγ and TNFα 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.

Psychosine-induced apoptosis and cytokine activation in immune peripheral cells of Krabbe patients†

Globoid cell leukodystrophy or Krabbe disease (KD), is a hereditary disorder caused by galactosylceramidase deficiency. Progressive accumulation of psychosine is considered to be the critical pathogenetic mechanism of cell death in the Krabbe brain. Psychosine mechanism of action has not been fully elucidated. It seems to induce apoptosis in oligodendrocytes through a mitochondrial pathway and to up‐regulate inflammatory cytokines production resulting in oligodendrocyte loss. Our aim was to evaluate the role of psychosine in apoptotic cell death and inflammatory response in a group of patients affected by KD using peripheral blood lymphocytes (PBLs) and peripheral blood mononuclear cells (PBMCs) as a cellular model. PBLs from KP and healthy controls were exposed to 20 µM psychosine and analysed by flow cytometry, agarose gel electrophoresis and fluorescence microscopy. Our results showed that psychosine induces apoptosis in PBLs through a mitochondrial pathway, but the apoptotic response was quite low especially KP. The role of psychosine in the up‐regulation of cytokines (TNFalpha, IL8 and MCP1) has been evaluated by ELISA in PBMCs from KP and controls after stimulation with LPS and phytohemagglutinin. Both in basal condition and after LPS stimulation, cells from KP showed a significant increase in TNF‐α production, reduced MCP1 levels and no modification in IL8. These results indicate that lymphomonocytes from KP had a basal proinflammatory pattern that was amplified by psychosine. In conclusion, the reduced apoptotic response and the atypical cytokine production observed in our experiments, suggest an involvement of inflammatory pattern in immune peripheral cells of KP. J. Cell. Physiol. 212:737–743, 2007.

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.

Different effect of statins on platelet oxidized-LDL receptor (CD36 and LOX-1) expression in hypercholesterolemic subjects.

Hydroxymethyl-glutaryl-CoA-reductase inhibitors (statins) reduce cardiovascular mortality by decreasing cholesterol as well as by non-lipid-related actions. Oxidized low-density lipoproteins (ox-LDL) are pro-atherogenic molecules and potent platelet agonists. CD36 and lectin-like ox-LDL receptor-1 (LOX-1) are specific ox-LDL receptors also expressed in platelets. This study was planned to address whether treatment with atorvastatin 10 mg/day, pravastatin 40 mg/day or simvastatin 20 mg/day could affect platelet CD36 and LOX-1 expression. Twenty-four patients for each treatment were evaluated after 3, 6, and 9 days and at 6 weeks for complete lipid profile (chromogenic), ox-LDL (ELISA), platelet P-selectin (P-sel), CD36, LOX-1 (FACS), and intracellular citrullin recovery (iCit) (HPLC). Data show hyperactivated platelets (P-sel absolute values, percent variation in activated cells, all p < 0.001), and CD36 and LOX-1 overexpression (all p < 0.001) in patients at baseline. P-sel, CD36, and LOX-1 were significantly decreased by atorvastatin and simvastatin (all p < 0.01) and related with iCit increase (r = 0.58,p < 0.001) and platelet-associated ox-LDL (r = 0.51, p < 0.01) at 9 days. Pravastatin reduced LOX-1 and P-sel (p < 0.05) at 6 weeks in relation with decreased LDL and ox-LDL (r = 0.39, p < 0.01 and r = 0.37, p < 0.01, respectively). These data suggest that atorvastatin and simvastatin reduce platelet activity by exposure of CD36 and LOX-1 before significant LDL reduction, whereas pravastatin action is detected later and in relation with LDL and ox-LDL lowering. Rapid and consistent reduction of CD36 and LOX-1 could be considered a direct anti-atherothrombotic mechanism related to the role of ox-LDL in platelet activation, platelet-endothelium interactions, and NO synthase activity.

Effects of carvedilol therapy on restrictive diastolic filling pattern in chronic heart failure

BACKGROUND Carvedilol therapy during congestive heart failure demonstrated a good efficacy in mortality rate reduction and in improvement of left ventricular (LV) systolic performance. However, currently there is not any finding about the drugs effect on diastolic filling. The aim of this study was to evaluate the effects of beta-blocker treatment on LV diastolic function with an eco-pulsed Doppler ultrasound scanning examination at transmitral level in a group of patients who were affected by heart failure with a restrictive filling pattern. METHODS We studied 27 patients with idiopathic or ischemic dilated cardiomyopathy with LV severe systolic disfunction (ejection fraction <35%). Fourteen patients were randomized to receive carvedilol treatment (carvedilol group), and 13 patients continued to receive standard therapy with angiotensin-converting enzyme inhibitors, diuretics, and vasodilators (placebo group). All patients underwent an echo-Doppler ultrasound scanning examination at the beginning of the study and after 4 and 12 months of treatment. RESULTS In the carvedilol group, we found a progressive improvement of Doppler ultrasound scanning parameters after 4 months, with a significant increase of A wave (P <.005), deceleration time (DT; P <.02) and isovolumetric relaxation time (IVRT; P <.02). These improvements were confirmed after 1 year of follow-up, whereas patients in the placebo group did not shown any significant modifications. After 1 year, the differences in these groups were more significant for A wave (39 +/- 4 cm/sec carvedilol group vs 30 +/- 4 cm/sec placebo group; P <.0001), for E/A ratio (1.8 +/- 0.2 carvedilol group vs 2.6 +/- 0.5 placebo group; P <.0002), for DT 1(40 +/- 16 msec carvedilol group vs 112 +/- 13 msec placebo group; P <.001), and for IVRT (74 +/- 8 msec carvedilol group vs 57 +/- 7 mesc placebo group; P <.0002). These changes seem to happen before systolic and morphological modifications. CONCLUSION Our results show that carvedilol therapy is a means of modifying parameters of diastolic filling favorably in patients with heart failure. These effects seem to be independent of those of systolic function. The improvement of systolic performance occurs after 1 year of treatment. The restrictive filling pattern, related to an unfavorable prognosis, changes toward pseudonormal or altered relaxation pattern during carvedilol therapy. Further investigations with a greater sample size will be necessary to confirm our findings.

Mechanisms for antiplatelet action of statins.

Hydroxymethyl-glutaryl coenzyme A reductase inhibitors (statins) offer important benefits for the large populations of individuals at high risk for coronary heart and cerebrovascular disease. the overall clinical benefits observed with statin therapy appear to be greater than what might be expected from changes in lipid profile alone, suggesting that the beneficial effects of such drugs may extend beyond their effects on serum cholesterol. Platelet hyperactivity is a key step in atherothrombosis and experimental data suggest that statins could exert an antiplatelet effect which could be involved in their protective action. In the present review we report of the major studies in humans showing the effect of statins on platelets, especially by the more sensitive methods to explore platelet function such as cytofluorymetric detection of specific proteins. Moreover we describe the putative mechanisms involved in platelet deactivation with particular regard to the effects related to cholesterol reduction or beyond lipid-lowering. Indeed, data from several studies suggest some differences among compounds in terms of timing of action by modulation of several activating pathways which could take part either in the early, cholesterol-lowering independent, effects in the acute phase of vascular disease or during chronic treatment.

Relationship between serum complement and different lipid disorders

Abstract Inflammatory and lipid factors share an important role in atherosclerosis. Recent studies showed the concomitant presence and increase of complement components and lipid both in the atherosclerotic plaque and the circulating blood. The aim of this study was to examine the relationship between the complement system and lipid disorders. We evaluated the circulating complement terminal complex C5b-9, a clear sign of complement activation, in three groups of 30 patients the first with hypercholesterolemia, the second with hypertriglyceridemia (associated with low values of HDL-cholesterol), the third with low levels of HDL-cholesterol compared with an equivalent group of matched normolipemic subjects. We found a significant increase of sC5b-9 in each group of patients compared with controls. The mean sC5b-9 level in the hypercholesterolemic population was 366.2±141.2 ng/ml (P<0.01), 395.4±118.2 ng/ml in the hypertrygliceridemic group (P<0.01), 414.8±126.4 ng/ml in the low HDL-chol subjects (P<0.01), and 182.0±40.8. ng/ml in the control group. Regression analysis showed a significant direct correlation between sC5b-9 and triglycerides (r=0.64), and a significant inverse correlation between sC5b-9, HDL-chol (r=0.74), and apo-A1 (r=0.68); no significant relationship was found between sC5b-9 and cholesterol. We suggest that complement activation is associated with the various lipid disorders and is more important in those dyslipidemic conditions in which other factors may be involved. In particular, hypertriglyceridemia may be associated with endothelial and fibrinolytic disturbances, and the decrease of HDL may induce the failure of the regulatory proteins transported by the same HDL.