[Show abstract][Hide abstract] ABSTRACT: Intracoronary Abciximab administration during primary percutaneous coronary intervention (pPCI) could offer theoretical advantages over the intravenous route. Besides antiplatelet effects, Abciximab can modulate inflammation via cross-reactivity with GPIIb/IIIa, avb3, and aMb2 receptors. The aim of our study was to assess whether the Abciximab administration route could influence its anti-inflammatory effects.
Journal of cardiovascular medicine (Hagerstown, Md.). 07/2014;
[Show abstract][Hide abstract] ABSTRACT: Venlafaxine (V) is a serotonin-norepinephrine selective reuptake inhibitor, mainly metabolized by cytochrome P4502D6 (CYP2D6). CYP2D6 polymorphisms result in a variety of phenotypes: poor (PMs), intermediate (IMs), extensive (EMs), and ultrarapid metabolizers (UMs). PMs usually show poor tolerance to drugs metabolized by CYP2D6, while UMs need greater doses. The aim of this study was to evaluate the impact of CYP2D6 genotype on V dosage, therapeutic response, and side effects in a clinical outpatient setting.
47 patients with Major Depressive Disorder, treated with V 75 - 300 mg/day, underwent CYP2D6 genotyping using the INFINITI-CYP2D6 assay. Duration of treatment and clinical outcome (Clinical Global Impression [CGI] effectiveness index) were assessed.
CGI assessment was performed after 6 weeks, 6 months, and 1 year of treatment with a V median dose of 150 mg/day. CYP2D6 genotyping resulted in 1 PM, 3 IMs, 42 EMs, and 1 UM. The UM took the greatest V dose (375 mg) without side effects; IMs/PMs took moderate/high doses of V (150 - 300 mg) without adverse effects; EMs displayed high response variability.
PM/IM patients responded to V differently than expected according to genotype. However, the UM patient responded to a dosage higher than the usual therapeutic range and without developing side effects, suggesting an association between CYP2D6 gene duplication and the therapeutic efficacy of venlafaxine. The CYP2D6 genotyping may thus provide clinicians with a potential explanation for those patients requiring greater doses of CYP2D6 substrates in order to obtain the same therapeutic efficacy.
[Show abstract][Hide abstract] ABSTRACT: In previous studies elevated Asymmetric NG, NG - dimethylarginine (ADMA) plasma levels, an endogenous nitric oxide synthase inhibitor, correlated with the severity of hepatic venous pressure gradient measurement, both in peripheral and in hepatic veins. The aim of this study was to explore whether elevated ADMA plasma levels were able to predict the presence of esophageal varices (EV) and/or large EV in patients with cirrhosis.
[Show abstract][Hide abstract] ABSTRACT: Glycoprotein IIb-IIIa (Gp IIb-IIIa), a fibrinogen receptor located on platelet surface, is a key point in the pathway leading to platelet aggregation. Therefore, great interest has emerged in the last decades on its pharmacological block, both by irreversible binding of abciximab or by competitive small molecules (tirofiban and eptifibatide). Gp IIb-IIIa inhibitors, in fact have demonstrated to provide benefits in clinical outcome among patients with acute myocardial infarction and in complex elective percutaneous coronary intervention (PCI) procedures. Still unclear is whether the genetic Leu 33Pro substitution in Gp IIIa may affect the extent of platelet aggregation inhibition by these drugs. Therefore, the aim was to evaluate whether this polymorphism (PlA) may influence inhibition of platelet aggregation after Gp IIb-IIIa administration in patients undergoing coronary angioplasty. We analyzed 80 patients undergoing nonurgent coronary revascularization and receiving Gp IIb-IIIa inhibitors (bolus and endovenous infusion; 40 patients with Abciximab and 40 patients with eptifibatide or tirofiban). The aggregation tests were performed at baseline and after 10 min, 1 h and 4 h, through multiplate impedance aggregometry. The PlA polymorphic variant was found in 26 patients (32.5%). The PlA carriers did not differ significantly from wild-type subjects for main clinical and angiographic features, except for in-stent restenosis that was more frequent among PlA carriers (P = 0.003). Therapy and aggregation values at baseline were similar in the two groups. The Leu33Pro substitution did not influence platelet response after Gp IIb-IIIa administration, which was confirmed for both abciximab and small molecules. This study showed that Leu33Pro polymorphism of Gp IIIa does not affect the extent of inhibition of platelet aggregation by Gp IIb-IIIa inhibitors.
Blood coagulation & fibrinolysis: an international journal in haemostasis and thrombosis 02/2013; · 1.25 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The increasing demand for therapeutic monitoring in patients receiving antiplatelet therapy has been paralleled by the development of instruments and tests whose clinical usefulness is still under debate. We devised a laboratory approach to detect patients with antiplatelet resistance at risk to develop thrombotic events.
One hundred and eighty patients, under aspirin and clopidogrel after angioplasty and stent implantation, were studied by PFA100(®) with collagen/epinephrine (CoEPI, cutoff 165s) cartridge and by Multiplate(®) using arachidonic acid (ASPItest, pos < 862AUC), ADP (ADPtest, pos < 417AUC), and collagen (COLtest, pos < 607AUC).
Only 67 of 173 patients with ASPI < 862 displayed a prolonged CoEPI and up to 65 patients had normal CoEPI despite ASPI < 300. Patients with ASPI < 300 had significantly lower COL than patients with ASPI > 300. One hundred and thirty-eight patients displaying ADP < 417 had significantly lower COL than those with ADP > 417. Association between COL and ADP remained after ASPI stratification: in patients with suboptimal (ASPI 300-892) or maximal (ASPI < 300) response to aspirin, having ADP < 417 (clopidogrel responsive) increased COL positivity, respectively, from 9.5 to 58.8% and from 47.6 to 82.7%.
A combination of specific tests may be useful in identifying higher-risk patients with poor compliance or drug resistance who potentially may benefit from therapy change.
International journal of laboratory hematology 05/2012; 34(5):484-94. · 1.30 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The side effects of tamoxifen, a drug widely used for the treatment and the prevention of recurrence in patients with estrogen receptor positive breast cancers (ER+), have been reported in clinical trials, but to date no information is available on their possible association with an increased enzymatic activity of CYP2D6 (ultra-metabolizers, UMs). The aim of this study was therefore to evaluate the association between the presence of multiple functional CYP2D6 alleles and the occurrence of side effects.
61 women with ER+ breast cancer receiving tamoxifen monotherapy were investigated in order to assess the relationships between CYP2D6 UM phenotype and side effects. Genotyping of 16 CYP2D6 polymorphisms was performed using a new DNA microarray technology.
A highly significant difference was detected (41.2% of difference, 95% CI 6 - 61%, Fisher's exact test, p = 0.030) between the numbers of Ultrarapid Metabolizer patients (UM; high activity) with two or more adverse drug reactions to tamoxifen (7/9; 77.8%), compared to the number of Extensive Metabolizers (EM; normal activity), Intermediate Metabolizers (IM; reduced activity), and Poor Metabolizers (PM; no activity) with at least two side effects (19/52, 36.5%). A similar difference was also observed comparing the two groups (UM vs EM-IM-PM) for the number of side effects (median and inter quartile range, IQR: AM/EM/IM 1, IQR 0-2 vs. ULTRA 2, IQR 2-4; Mann-Whitney p = 0.005).
Our results suggest a new association between CYP2D6 gene duplication and side effects to tamoxifen, indicating a possible role of CYP2D6 in their occurrence.
[Show abstract][Hide abstract] ABSTRACT: The oral glucose tolerance test (OGTT) is widely employed to evaluate insulin resistance in children with growth hormone deficiency. Due to the difficulty in blood sampling, hemolysis is a frequent pre-analytic interference. The present study was performed to characterize the effects of hemolysis on insulin assays, in order to assess the need to generate automatic hemolysis reports and/or to reject hemolyzed samples.
Insulin plasma levels were measured using a Siemens ADVIA Centaur on samples obtained from children with suspected GH deficiency at risk for insulin resistance during OGTT.
The presence of hemolysis (with a concentration of free hemoglobin above 75 mg/dL) promotes a dose- and time-dependent decrease in immunoreactive insulin at any time-point evaluated during OGTT. As a consequence, the variability of insulin is particularly high (often exceeding 100% of the mean value) as compared to that of glucose. This variability is markedly reduced after removal of the hemolyzed samples.
When hemolysis is not taken into account a misinterpretation of insulin secretion pattern can occur. It is therefore imperative to: (i) analyze blood samples immediately after sampling, (ii) reject samples with a concentration of free hemoglobin equal to or above 125 mg/dL and (iii) always report the possible interference.
[Show abstract][Hide abstract] ABSTRACT: Plasma fibrinogen levels influence restenosis following elective percutaneous coronary intervention (PCI) for stable angina. It is unknown whether the same is true in the setting of primary PCI. The aim of the study was therefore to assess whether fibrinogen levels were associated to 6-month in-stent restenosis (ISR) in STEMI patients undergoing successful primary PCI. From January 2003 to October 2004, 267 patients were admitted to our Institution for STEMI and treated by primary PCI. Of these, 171 patients met the inclusion criteria and were enrolled in our study. Fibrinogen levels were assessed at admission, 12 h, 24 h, 48 h, 72 h following PCI and at discharge. Six-month angiographic follow-up was 100% complete. Subjects with 6-month ISR showed higher fibrinogen levels than patients without ISR. Patients in the upper fibrinogen tertile showed a higher 6-month incidence of symptoms and/or inducible myocardial ischemia (27.1% vs. 7.1%, P = 0.006) and a larger late lumen loss (1.3 ± 0.8 vs. 1.0 ± 0.9 mm, P = 0.049). Logistic regression analysis demonstrated a significant and independent association between fibrinogen levels and ISR. Our study suggests that increased plasma fibrinogen levels are related to ISR in STEMI patients undergoing primary PCI. Larger studies are warranted to assess the prognostic value of fibrinogen over harder end-points.
Journal of Thrombosis and Thrombolysis 09/2011; 33(4):308-17. · 1.99 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The activated protein C resistance--sensitivity ratio in the presence of Factor V deficient plasma (APC-SR/Factor V) exhibits a high sensitivity for factor V Leiden mutation and has been proposed as the diagnostic approach of choice, as an alternative to genetic tests, to evaluate activated protein C resistance. A survey, including 4969 requests, was performed on the activity of a typical Molecular Diagnostics Laboratory in order to estimate the costs due to reagents, instrumentation and personnel.
The global costs of three hypothetical diagnostic approaches were compared: (A) exclusive molecular test for FV Leiden; (B) APC-SR alone; (C) APC-SR and the exclusive confirmation of positive results with molecular test.
The global cost for each patient with the three approaches investigated were respectively 42.20 euros (A), 1.09 euros (B), and 433 euros (C). The cost for finding a patient with factor V Leiden mutation was 549.00 euros for A, 14.18 euros for B, and 56.32 euros for C. It was calculated that a decrease of 97.42% and 89.74% can be obtained using the approaches B and C, respectively. The difference in cost between B and C can be justified by the avoidance of false positive cases (6%) and by the impossibility of distinguishing homozygous from heterozygous patients using APC-SR exclusively (B).
In the case of suspected phenotype APC resistance, we suggest a laboratory approach, which provides the combined and sequential use of ProCGlobal/FV analysis and a subsequent genetic test for positive patients.
[Show abstract][Hide abstract] ABSTRACT: Lupus anti-coagulants (LA) are a variety of anti-phospholipid antibodies characterized by their capacity to interfere with phospholipid-dependent coagulation assays. LA are increasingly recognized as important predictors of thrombosis. However, the antigen specificity of LA is still poorly characterized. Growing evidence indicates that oxidized phospholipids are among the targets of anti-phospholipid antibodies. This prompted us to investigate the role of IgG directed against different oxidized phospholipids in 164 subjects without clotting factor defects that were tested for the presence of LA using a LA-sensitive activate partial thromboplastin time (aPTT-FSL) and a screening/confirmation assay based on diluted Russell's viper venom test (dRVVT-PL). The response to aPTT-FSL was significantly (P < 0.0005) associated with high titres of IgG against oxidized phosphatidylserine, phosphatidylethanolamine and phosphatidylinositol, whereas positivity to dRVVT-PL was associated with the elevation of IgG against oxidized phosphatidylserine, phosphatidylcholine, phosphatidylethanolamine (P < 0.0005) and phosphatidylinositol (P < 0.01). No difference in reactivity against oxidized cardiolipin was evident between the different groups. Positivity to the dRVVT-PL test was also associated significantly (P < 0.005) with the elevation of anti-cardiolipin and anti-beta(2)-glycoprotein-1 IgG. However, stepwise logistic regression demonstrated that IgG recognizing oxidized phosphatidylethanolamine and oxidized phosphatidylcholine were the only independent predictors of the response to dRVVT-PL assay, while IgG recognizing oxidized phosphatidylethanolamine and oxidized phosphatidylinositol were independent predictors of the response to aPTT-FSL test. In conclusion, autoantibodies against defined oxidized phospholipids are independent predictors of LA detection by aPTT-FSL or dRVVT-PL assays and might contribute to the variability often observed in the responses to the functional tests detecting LA.
[Show abstract][Hide abstract] ABSTRACT: Iron accumulation is a well-known risk factor for the progression of chronic hepatitis C (CHC) to fibrosis. However, the profibrogenic role of the genes controlling iron homeostasis is still controversial.
To evaluate the relative role of haemachromatosis (HFE), ferroportin and beta-globin gene mutations in promoting iron accumulation and fibrosis in patients with CHC.
Genetic analysis was performed together with the assessment of hepatic iron content and histology in 100 consecutive HIV-antibody and hepatitis B surface antigen-negative patients with biopsy-proven CHC.
Among the patients investigated, 12 were heterozygous for various beta-globin gene mutations (39[C-->T], IVS1.1[G-->A], 22 7 bp deletion and IVS1.6[T-->C]) and 29 carried HFE (C282Y, H63D and S65C) gene mutations. One further patient was heterozygous for both HFE (H63D) and beta-globin (39[C-->T]) variants, whereas 58 had the wild-type alleles of both the genes. Hepatic iron concentration (HIC) and hepatic stainable iron were significantly higher (p<0.05) in patients with CHC carrying beta-globin mutations than in those with HFE mutations or the wild-type alleles. Multivariate analysis confirmed that the presence of beta-globin mutations was independently associated with both HIC (p = 0.008) and hepatic-stainable iron (odds ratio (OR) 6.11; 95% CI 1.56 to 23.92; p = 0.009). Moderate/severe fibrosis or cirrhosis (Ishak's score >2) was observed in 48 of 100 patients. Logistic regression demonstrated that age (OR 1.05; 95% CI 1.02 to 1.09; p<0.005) and beta-globin mutations (OR 4.99; 95% CI 1.22 to 20.3; p = 0.025) were independent predictors of the severity of fibrosis.
Heterozygosis for beta-globin mutations is a novel risk factor for both hepatic iron accumulation and the progression to fibrosis in patients with CHC.
[Show abstract][Hide abstract] ABSTRACT: The identification of the epitopes recognized by autoantibodies against cytochrome P450s (CYPs) associated with drug-induced hepatotoxicity is difficult because of their conformational nature. In the present investigation, we used a novel approach based on the analysis of the whole molecule antigenic capacity following single amino acid substitutions to identify the conformational epitopes on CYP2E1. A molecular model of CYP2E1 was generated based on the CYP2C5 crystal structure, and potential motifs for amino acid exchanges were selected by computer simulation in the surface of alpha helices and beta sheets. Fourteen modified, apparently correctly folded CYP2E1 variants were produced in Escherichia coli and evaluated in immunoprecipitation experiments using sera with anti-CYP2E1 autoreactivity from 10 patients with halothane hepatitis and 12 patients with alcoholic liver disease. Ala substitution of Glu-248 and Lys-251 as well as of Lys-324, Lys-342, Lys-420, and Phe-421 severely decreased or abolished CYP2E1 recognition by the majority of both the halothane hepatitis and alcoholic liver disease sera, whereas the other substitutions had only minor effects. Based on the structural model, these substitutions identified two distinct epitopes on the CYP2E1 surface corresponding to the G-helix and an area formed by juxtaposition of the J' and K'' helices, respectively. The combined use of molecular modeling and single amino acid mutagenesis is thus a useful approach for the characterization of conformational epitopes recognized by autoantibodies.
Journal of Biological Chemistry 01/2005; 279(49):50949-55. · 4.65 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Autoimmune reactions are often associated with alcoholic liver disease; however, the mechanisms responsible are largely unknown. This study investigates the potential role of the immune response against hydroxyethyl free radical (HER)-derived antigens and of polymorphisms in immunoregulatory genes in the development of anti-cytochrome P4502E1 (CYP2E1) autoantibodies in alcohol abusers. Immunoglobulin G (IgG) recognizing human CYP2E1 and HER-derived epitopes were measured by microplate immunosorbent assay in the sera of 90 patients with alcoholic fibrosis/cirrhosis (ALD), 37 heavy drinkers without liver disease or steatosis only (HD), and 59 healthy subjects. Single nucleotide polymorphisms in the interleukin 10 (IL-10) promoter and in exon 1 of the cytotoxic T-lymphocyte antigen-4 (CTLA-4) gene were genotyped by polymerase chain reaction-restriction fragment length polymorphism analysis. The titers and frequency of anti-CYP2E1 autoantibodies were significantly higher in ALD than in HD subjects or controls. ALD patients with anti-HER IgG had higher titers and a 4-fold increased risk (OR: 4.4 [1.8-10.9]) of developing anti-CYP2E1 autoantibodies than subjects without anti-HER antibodies. The mutant CTLA-4 G allele, but not the IL-10 polymorphism, was associated with an enhanced risk of developing anti-CYP2E1 IgG (OR: 3.8 [1.4-10.3]). CTLA-4 polymorphism did not influence antibody formation toward HER-antigens. ALD patients with concomitant anti-HER IgG and the CTLA-4 G allele had a 22-fold higher (OR: 22.9 [4.2-125.6]) risk of developing anti-CYP2E1 autoreactivity than subjects negative for these factors. In conclusion, antigenic stimulation by HER-modified CYP2E1 combined with an impaired control of T-cell proliferation by CTLA-4 mutation promotes the development of anti-CYP2E1 autoantibodies that might contribute to alcohol-induced liver injury.
[Show abstract][Hide abstract] ABSTRACT: The mechanisms by which alcohol consumption worsens the evolution of chronic hepatitis C (CHC) are poorly understood. We have investigated the possible interaction between hepatitis C virus (HCV) and ethanol in promoting oxidative stress. Circulating IgG against human serum albumin (HSA) adducted with malondialdehyde (MDA-HSA), 4-hydroxynonenal (HNE-HSA), or arachidonic acid hydroperoxide (AAHP-HSA) and against oxidized cardiolipin (Ox-CL) were evaluated as markers of oxidative stress in 145 CHC patients with different alcohol consumption, 20 HCV-free heavy drinkers (HD) without liver disease, and 50 healthy controls. Anti-MDA IgG was increased in CHC patients irrespective of alcohol intake as well as in the HD group. CHC patients with moderate alcohol intake (<50 g ethanol/d), but not HD, also had significantly higher values of anti-AAHP-HSA, anti-HNE-HSA, and anti-Ox-CL IgG (P <.05) than controls. A further elevation (P <.001) of these antibodies was evident in CHC patients with heavy alcohol intake (>50 g ethanol/d). Anti-AAHP and anti-Ox-CL IgG above the 95th percentile in the controls were observed in 24% to 26% of moderate and 58% to 63% of heavy drinkers but only in 6% to 9% of the abstainers. The risk of developing oxidative stress during CHC was increased 3-fold by moderate and 13- to 24-fold by heavy alcohol consumption. Heavy drinking CHC patients had significantly more piecemeal necrosis and fibrosis than abstainers. Diffuse piecemeal necrosis was 4-fold more frequent among alcohol-consuming patients with lipid peroxidation-related antibodies than among those without these antibodies. In conclusion, even moderate alcohol consumption promotes oxidative stress in CHC patients, suggesting a role for oxidative injury in the worsening of CHC evolution by alcohol.
[Show abstract][Hide abstract] ABSTRACT: The role of genetic factors in the pathogenesis of alcohol-induced liver disease (ALD) is receiving increasing attention. Recently, it has been reported that homozygosity for a valine to alanine substitution in the mitochondrial targeting sequence of manganese superoxide dismutase (Mn-SOD) represents a risk factor for severe ALD. Because this mutation is postulated to modify enzyme transport into mitochondria, we have sought confirmatory evidence of this association in a larger group of patients and investigated whether this polymorphism might influence alcohol-induced oxidative stress. Genotyping for the valine-alanine (Val-Ala) polymorphism of the Mn-SOD gene in 281 patients with advanced ALD (cirrhosis/fibrosis) and 218 drinkers without liver disease showed no differences in either the heterozygote (55% vs. 50%) or the homozygote (19% vs. 23%) frequency for the alanine allele. By measuring the titers of circulating antibodies against oxidized cardiolipin (OX-CL) and malondialdehyde (MDA) or hydroxy-ethyl radical (HER) adducts as markers of oxidative stress, we found a significant increase in ALD patients compared with healthy controls. However, the carriers of the alanine Mn-SOD allele had titers of anti-MDA, anti-HER, and anti-OX-CL IgG comparable with heterozygotes and patients homozygous for the valine allele. Similarly, the frequency of subjects with antibody titers above the 95th percentile of controls was not increased among homozygotes for the alanine Mn-SOD allele. In conclusion, in our population Val-Ala polymorphism in Mn-SOD influences neither susceptibility to alcohol-induced liver fibrosis nor alcohol-induced oxidative stress.