Myeloperoxidase overexpression in children with hypercholesterolemia

BACKGROUND

Studies conducted in healthy children showed that biomarkers of oxidative stress decreased with increasing age from 1 to 11 years. No data have been reported concerning the behavior of age-related oxidative stress in hypercholesterolemic children.

OBJECTIVE

Aim of this study was to test if children with hypercholesterolemia have prolonged exposure to enhanced oxidative stress and to study the underlying mechanism.

METHODS

We performed a cross-sectional study comparing 8-hydroxy-2'deoxyguanosine, oxidized-LDL and myeloperoxidase plasma levels in 95 normocholesterolemic and 95 hypercholesterolemic children.

RESULTS

Compared to normocholesterolemic children, those with hypercholesterolemia had higher 8-hydroxy-2'deoxyguanosine, oxidized-LDL and myeloperoxidase plasma levels. A correlation analysis of the overall population showed that total cholesterol was directly correlated with 8-hydroxy-2'deoxyguanosine, oxidized-LDL and myeloperoxidase. Stepwise linear regression showed that only total cholesterol, 8-hydroxy-2'deoxyguanosine and myeloperoxidase levels predicted oxidized-LDL plasma levels. In normocholesterolemic children oxidized-LDL and myeloperoxidase plasma levels significantly decreased from first (1-5 years) to second (6-9 years) quartile of age. In hypercholesterolemic children 8-hydroxy-2'deoxyguanosine, oxidized-LDL and myeloperoxidase plasma levels did not show significant differences among quartiles of age.

CONCLUSION

This study shows that an early and persistent oxidative stress is detected in hypercholesterolemic children and that myeloperoxidase up-regulation might play a role.

[Arterial hypertension and cardiovascular risk: need for a combined strategy of intervention]

Arterial hypertension represents one of the most common conditions associated with an increased cardiovascular risk. New evidences support the need to adopt a global approach to the treatment of cardiovascular risk in hypertensive subjects by using drugs with proven benefits, not only for blood pressure control, but also for their pleiotropic effects. A greater understanding of the pathogenetic mechanisms of hypertension would provide a better strategy for preventing and treating this condition. Angiotensin II seems to be responsible for triggering vascular inflammation by inducing oxidative stress, resulting in up-regulation of pro-inflammatory mediators that lead to endothelial dysfunction and vascular injury. The interaction of angiotensin II, oxidative stress and endothelial dysfunction might be a target of a new integrated approach with important clinical implications.

CD40/CD40L system and vascular disease

Several distinct lines of investigation in the context of atherosclerosis dealing with low-grade inflammation, oxidative stress and platelet activation are now emerging, with CD40/CD40L system as the missing link. CD40 ligand is a transmembrane glycoprotein structurally related to tumour necrosis factor-alpha and more than 95% of the circulating CD40L derives from platelets. CD40L appears as a multiplayer of several cell types in the inflammatory network. The peculiarity of CD40L as an inflammatory mediator derived from platelets expands the functional repertoire of platelets from players of haemostasis and thrombosis to powerful amplifiers of inflammation by promoting the release of cytokines and chemokines, cell activation and cell-cell interactions. The multifunctional role of CD40L, as a simultaneous activator of all these systems, further blurs the intricate relationship between such events both in the physiological systems and the pathological derangement occurring in atherothrombosis.

Contribution of Platelet-Derived CD40 Ligand to Inflammation, Thrombosis and Neoangiogenesis

CD40-CD40L interactions have been involved in inflammation and thrombosis. Several diseases are characterized by inflammation, hypercoagulability and increased prevalence of thromboembolic events. In the past decade, a series of preclinical and clinical studies has provided more insight into the pathogenetic mechanisms linking inflammatory mediators to the activation and regulation of the haemostatic system. In particular, the study of CD40-CD40L interactions has greatly contributed to understanding the role of platelets in a variety of pathophysiological conditions, including atherothrombosis, immuno-inflammatory diseases and, possibly, cancer. A wide variety of preclinical and clinical studies have generated clinical interest in the use of CD40L as a prognostic marker of thrombotic risk. However, the use of sCD40L in clinical studies requires reliable methods. For the correct interpretation of results, clinical and research laboratories and physicians must be aware of the limitations of immunoassays for this cytokine, which underlines the need for standardization of preanalytic conditions. This review will focus on biochemical evidence of CD40L involvement in platelet activation, contribution of platelet-derived CD40L to inflammation, thrombosis and neoangiogenesis, and possible methodological pitfalls regarding the appropriate specimen and preparation for laboratory evaluation of blood soluble CD40L as a biomarker in various human diseases characterized by underlying inflammation, such as atherothrombosis, cancer and immuno-inflammatory diseases.

Proinflammatory cytokines and hemostatic system in patients with chronic obstructive pulmonary disease

The prothrombotic state frequently observed in patients with chronic obstructive pulmonary disease (COPD) may be related to a systemic inflammatory response. In the present study plasma interleukin-6 (IL-6), IL-2 and IL-1beta levels have been investigated in 33 patients with COPD. In vitro platelet activity, plasma C-reactive protein (CRP) and fibrinogen levels were also determined in all patients. The results obtained demonstrated that plasma IL-6 levels were significantly higher in the patient group compared with a control population age and sex-matched ( P < 0.02), while plasma IL-2 and IL-1beta levels were not significantly modified. An overall condition of platelet hyperactivity in COPD patients was also observed. A comparative analysis of platelet activity and blood gas levels demonstrated a correlation between platelet hyperactivity and a severe impairment of oxygen ( P < 0.001) and carbon dioxide tensions ( P < 0.01). Finally, a statistical analysis of the population under study showed the presence of a significant correlation between elevated plasma IL-6 ( P < 0.001) and IL-1beta levels ( P < 0.007), and an increased sensitivity of platelets to arachidonic acid, suggesting a possible correlation between the inflammatory response and the prothrombotic state observed in patients with COPD.

Endothelial dysfunction and oxidative stress in arterial hypertension

A large body of evidence indicates that endothelial dysfunction is a characteristic of patients with essential hypertension. By definition, endothelial dysfunction is a functional and reversible alteration of endothelial cells, resulting from impairment in nitric oxide (NO) availability and oxidative stress. Superoxide anion is a major determinant of NO biosynthesis and also acts as a vasoconstrictor. In addition, NO synthase (NOS) can generate superoxide rather than NO in response to atherogenic stimuli ("NOS uncoupling"). Under these circumstances, NOS may become a peroxynitrite generator, leading to a dramatic increase in oxidative stress, since peroxynitrite has additional detrimental effects on vascular function by lipid peroxidation. Increased levels of biomarkers of lipid peroxidation and oxidative stress have been found in patients with hypertension. In particular, patients with hypertension-related microvascular changes showed increased lipid peroxidation and platelet activation when compared with patients with absent or early signs of retinopathy. Furthermore, oxidant stress has been shown to play an important role in promoting a prothrombotic state in the vascular system. For all these reasons, endothelial dysfunction is evoked in hypertensive patients as promotor of vascular progressive damage and atherosclerotic and thrombotic complications through the enhanced oxidative stress of arterial walls. This broadens the cardiovascular risk of hypertensive patients and explains the insufficient role of the strict BP reduction in the prevention of vascular complications, thus opening up new perspectives on the antioxidant properties of currently available antihypertensive drugs and supplementation with antioxidant principles.

Platelet activation in type 2 diabetes mellitus

The abnormal metabolic state that accompanies diabetes renders arteries susceptible to atherosclerosis, being capable of altering the functional properties of multiple cell types, including endothelium and platelets. In particular, an altered platelet metabolism and changes in intraplatelet signaling pathways may contribute to the pathogenesis of atherothrombotic complications of diabetes. A variety of mechanisms may be responsible for enhanced platelet aggregation. Among them, hyperglycemia may represent a causal factor for in vivo platelet activation, and may be responsible for nonenzymatic glycation of platelet glycoproteins, causing changes in their structure and conformation, as well as alterations of membrane lipid dynamics. Furthermore, hyperglycemia-induced oxidative stress is responsible for enhanced peroxidation of arachidonic acid to form biologically active isoprostanes, which represents an important biochemical link between impaired glycemic control and persistent platelet activation. Finally, increased oxidative stress is responsible for activation of transcription factors and expression of redox-sensitive genes leading to a phenotypic switch of endothelium toward an adhesive, pro-thrombotic condition, initial platelet activation, adhesion and subsequent platelet aggregate formation. All this evidence is strengthened by the results of clinical trials documenting the beneficial effects of metabolic control on platelet function, and by the finding that aspirin treatment may even be more beneficial in diabetic than in high-risk non-diabetic patients. Attention to appropriate medical management of diabetic patients will have great impact on long-term outcome in this high-risk population.

Correlation between tumor necrosis factor-alpha and d-dimer levels in non-small cell lung cancer patients

The present study was designed to investigate whether a correlation exists between IL-6, TNF-alpha and coagulation (Thrombin-antithrombin, TATc) or fibrinolysis (D-dimer) activation in non-small cell lung cancer (NSCLC) patients. One hundred thirty patients with NSCLC (n=65, 53 males, mean age 65 +/- 8, adenocarcinoma n=32, squamous cancer n=33) or chronic obstructive pulmonary disease (COPD) (n=65, 51 males, mean age 67 +/- 9) were studied. As control group 65 healthy donors (51 males, mean age 61 +/- 14) were also evaluated. The results obtained showed that median D-dimer levels were higher in NSCLC patients (3.0 microg/ml) compared either to COPD patients (1.1 microg/ml, P<0.05) or controls (0.3 microg/ml, P<0.0001). Positive TNF-alpha levels (>10 pg/ml) were found in 26% of NSCLC compared to 3% of COPD (P<0.002) and 5% of controls (P<0.0005). On the other hand, positive (>8.5 pg/ml) IL-6 levels were found in 53% of NSCLC and 21% of COPD patients, compared to 5% of control subjects (P<0.001). Median TATc levels were elevated in either NSCLC (6.9 microg/l) or COPD (5.7 microg/l) patients compared to controls (1.8 microg/l, P<0.0001). Elevated D-dimer levels were significantly associated to positive TNF-alpha levels in patients without distant metastasis (F=4.3, P<0.05). Moreover, TNF-alpha levels (P<0.01) were independently related to the presence of positive D-dimer levels in patients with non-metastatic NSCLC. These results suggest that increased levels of TNF-alpha might be responsible for an activation of fibrinolysis in patients with NSCLC.

Joint sonography in asymptomatic patients with HCV correlated hepatitis

OBJECTIVES

Many different articular symptoms may appear in patients with HCV hepatitis, but in a relatively large number of patients no rheumatic symptoms are present. This sonographic study was undertaken to detect the possible presence of early articular changes in HCV patients without any rheumatic manifestations.

METHODS

The knee, hip and shoulder were evaluated in a cohort of 29 consecutive HCV patients without any rheumatic symptoms. Results were compared with those obtained by the evaluation of 29 healthy subjects who were negative for markers of HCV and HBV infections.

RESULTS

Results showed the presence of alterations in 96.5% of the patients, with significant differences in comparison to controls (p < 0.0001). Slight inflammatory changes were found in all the joints examined. The knee was involved in 79.3% of the cases, the hip in 27.6% and the shoulder in 89.6%.

CONCLUSIONS

Our preliminary study shows the presence of joint changes in the majority of cases. To the best of our knowledge this is the first ultrasonographic study to focus on joint evaluation in patients with HCV hepatitis. Broader epidemiological and virological investigations, in particular for the HCV subtype and HLA genotype, will be required to elucidate the relationship between HCV infection and rheumatic symptoms.

Leptin increase is associated with markers of the hemostatic system in obese healthy women

BACKGROUND

Leptin, a hormone secreted by the adipose tissue, might be a link between obesity and increased morbidity for cardiovascular disease. Leptin exerts proinflammatory, pro-angiogenic actions by activating a specific receptor (Ob-Rb) which is expressed in human endothelial cells. Thus, a link may exist between leptin expression and endothelial dysfunction.

OBJECTIVES

We sought to determine whether in obese women there is a correlation between leptin levels, endothelial perturbation and coagulative activation.

METHODS

Circulating levels of leptin, von Willebrand Factor (VWF), factor (F)VIIa, prothrombin fragment 1 + 2 (F1+2), were measured in 51 non-diabetic, obese women and in 51 normal-weight subjects, using immunoenzymatic assays.

RESULTS

Obese women had significantly higher levels of leptin, VWF, FVIIa, F1+2 compared with healthy women. Simple correlation coefficients showed significant correlation between leptin and either VWF, FVIIa, or F1+2 concentrations. A multiple linear regression analysis, performed to quantify further the relationship between leptin levels and the above-mentioned variables as well as the inflammatory marker C-reactive protein (CRP) and including age, body mass index (BMI), waist-hip ratio (WHR) and lipid parameters as potential confounders, revealed that only FVIIa and VWF were independently related to leptin levels. Reduction in adipose tissue after weight loss resulted in a decrease in both circulating leptin and endothelial and coagulative activation markers.

CONCLUSIONS

We suggest that leptin might have pro-atherogenic effects in vivo, with a mechanism involving endothelial cell activation.

Prevalence and clinical features of skin diseases in chronic HCV infection. A prospective study in 96 patients

BACKGROUND

Between extra-hepatic manifestations of hepatitis C virus (HCV) infection particular interest is focused on some dermatological diseases such as: leukocytoclastic vasculitis, oral lichen planus, pruritus-urticaria, psoriasis, etc. The aim of this study was to determine the prevalence of some dermatoses in our population of patients with HCV infection and describe the more characteristics clinical pictures.

METHODS

Ninety-six patients (36 men and 60 women) aged from 35 to 74 years with HCV documented by 3rd generation ELISA and RIBA tests were prospectively examined for 3 years to determine the prevalence of some skin disorders, reported as associated with HCV infection. All patients were also studied for presence and quantification of HCV-RNA by polymerase chain reaction and genotyping when possible. Eighty-one underwent a liver biopsy. Routine laboratory tests and some immunological investigations (ANA, AMA, SMA, LKM, ANCA, ICC, crioglobulins) were performed using standard procedures and indirect immunofluorescence, nephelometric, RIA methods.

RESULTS

Twelve of 96 patients (12.5%) presented skin disorders in progress of chronic virus C hepatitis: 5 cases of leukocytoclastic vasculitis (LCV) by mixed cryoglobulinemia, 1 case of pruritus, 2 cases of oral lichen planus (OLP), 2 cases of alopecia areata, 1 case of urticaria, 1 case of psoriasis.

CONCLUSIONS

Our findings show a calculated prevalence of clinical dermatoses in HCV infected patients around 12.5%. These findings confirm however the importance of liver examination in presence of skin diseases not related to other pathogenetic mechanisms.

Soluble selectin levels in patients with lung cancer

Increased expression of selectins has been found on endothelial cells of venules and capillaries in the tumor stroma of non-small cell lung cancer, suggesting their functional role in the process of chemotaxis for tumor cells. The present study was aimed at analyzing the role of both soluble (s)P-selectin and sE-selectin levels in association with clinico-pathological variables in 116 patients with lung cancer, 38 patients with benign diseases and 59 healthy donors. The results obtained showed that sP-selectin and sE-selectin levels were higher in patients with lung cancer compared to normal donors (p<0.02 and p<0.005, respectively). No differences were observed among patients with various benign diseases for both selectins. Increased levels of sP-selectin and sE-selectin were significantly associated with squamous lung cancer at late stages (p<0.05), but not adenocarcinoma. Both sP- and sE-selectin were independently related to the stage of squamous lung cancer by stepwise regression analysis (p<0.02 and p<0.03, respectively), while only sE-selectin was independently related to the presence of distant metastasis in the same histotype (p<0.02). These results suggest that measurement of plasma soluble selectins might represent a useful laboratory parameter in the management of patients with squamous lung cancer.

Effects of mud-pack treatment on plasma cytokine and soluble adhesion molecule levels in healthy volunteers

BACKGROUND

The suggested hypothesis of a direct anti-inflammatory property of mud-pack treatment has led us to speculate that its action on the cytokine network might counteract the heat-stress-related effects on platelet and endothelial cell function often reported following hot-spring baths. Therefore, the present study was designed to investigate the effects of a cycle of 12 daily mud-pack treatments on bio-humoral markers of inflammation, as well as on markers of in vivo platelet and/or endothelial cell activation, in plasma samples obtained from healthy volunteers.

METHODS

Blood samples were obtained before (T(0)), at the end of the first treatment (T(1)) and after a cycle of 12 daily mud-pack treatments (T(2)). Plasma cytokines (TNF-alpha IL-1beta, and IL-6) and adhesion molecules (sP-selectin, sE-selectin and sVCAM) levels, as well as hematocrit and complete and differential blood cell counts were determined at every time point.

RESULTS

Plasma sP-selectin levels were not modified during treatment, as were not sE-selectin or sVCAM. Similarly, IL-1beta and TNF-alpha levels were unchanged through a 12 daily mud-pack treatment. Conversely, plasma IL-6 levels were significantly lowered at the end of a 20-min 47 degrees C mud-pack treatment (p<0.01).

CONCLUSIONS

The lack of effects on in vivo platelet and/or endothelial cell activation suggests that hot mud-pack treatment might be used as a relatively safe procedure in patients with atherothrombotic disorders.

Increased soluble P-selectin levels in hepatitis C virus-related chronic hepatitis: correlation with viral load

BACKGROUND

Platelet functional abnormalities are commonly found in patients with chronic liver disease; however, their nature and clinical significance are still a matter of discussion.

METHODS

Soluble P-selectin (sP-selectin, a marker of in vivo platelet activation) levels, lipid pattern, and clotting activity were investigated in 39 patients with histologically confirmed chronic C hepatitis.

RESULTS

Serum factor VIIc (P < 0.01), total cholesterol (P < 0.005), high density lipoprotein (P < 0.001), and low density lipoprotein (P<0.05) levels were lower in patients compared with healthy subjects, whereas triglyceride and fibrinogen levels were similar in both groups. Platelet counts were lower in chronic hepatitis patients compared with controls (P < 0.0001), and approximately 20% of patients had thrombocytopenia (platelet counts < 110 x 10(3)/microL). Platelet-associated immunoglobulin G (PAIgG) was present in 30.8% of patients. Plasma sP-selectin levels were higher in hepatitis C patients compared with controls (P < 0.0001), and significant differences were observed with respect to the Scheuer score (P < 0.01). The analysis of the distribution of plasma sP-selectin showed the presence of higher levels in patients with low platelet counts compared with patients with normal platelet counts and controls (P < 0.0001); moreover, sP-selectin levels did not correlate with the presence of PAIgG. On the other hand, sP-selectin levels directly correlated with serum hepatitis C virus (HCV)-RNA (P < 0.05) and inversely correlated with platelet count, blood lipids, and factor VIIc.

CONCLUSIONS

The results obtained in this study support the hypothesis that HCV infection might be directly responsible for a condition of in vivo platelet activation in patients with chronic C hepatitis.

Determinants of enhanced thromboxane biosynthesis in renal transplantation

BACKGROUND

Despite great improvement in patient and graft survival, the long-term morbidity and mortality in renal transplant recipients (RTRs) are still significant, with a high incidence of cardiovascular disease-related deaths.

METHODS

We investigated thromboxane (TXA2) biosynthesis and endothelial and coagulative activation in 65 patients who received a renal transplant.

RESULTS

The rate of TXA2 biosynthesis (urinary 11-dehydro-TXB2 excretion largely reflects platelet TXA2 production in vivo) was significantly (P < 0.0001) higher in RTRs than in healthy subjects. Plasma von Willebrand factor (vWF) and thrombin-antithrombin (TAT) complexes were significantly higher (P < 0.001) in RTRs compared with controls. Urinary 11-dehydro-TXB2 directly correlated with plasma vWF and cholesterol. We next examined the relative influence of cyclosporine A (CsA) on TXA2 biosynthesis and endothelial activation, comparing a group of RTRs not receiving CsA with an age- and sex-matched group of patients treated with CsA. Urinary excretion of 11-dehydro-TXB2 and plasma levels of vWF were significantly increased in RTRs who received CsA compared with those who did not. After an overall follow-up of 120 months, RTRs who experienced cardiovascular events had a higher frequency of abnormal plasma levels of vWF than patients who remained event free.

CONCLUSION

Renal transplantation is associated with in vivo platelet activation highly related to endothelial activation. This is particularly evident in CsA-treated patients. Administration of drugs that are able to reduce or eliminate thromboxane-dependent platelet activation in vivo may be beneficial to reduce the risk of cardiovascular events in RTRs.