Fibrillin-1 (FBN1) gene frameshift mutations in Marfan patients: genotype-phenotype correlation.

Marfan syndrome (MFS) is a multisystemic disease associated with mutations in the fibrillin-1 gene. Most of the reported mutations are missense substitutions mainly affecting the epidermal growth factor (EGF)-like protein domain structure and the calcium-binding (cb) site. The aim of our study was to investigate the correlation between fibrillin-1 frameshift mutations and the clinical phenotype in patients affected by MFS. In 48 out of 66 Marfan patients a pathogenetic mutation was found. We detected novel mutations causing premature termination codon in exons 19, 37, 40 and 41 of four Italian patients. The first mutation in exon 19 (cbEGF #8 domain) results in a clinical phenotype involving mainly the skeletal and cardiovascular systems. Interestingly, we noticed that, while mutations in exons 37 and 41 (eight cysteine domains #4 and #5) are milder, the mutation in exon 40 (cbEGF #24 domain) is more severe and causes major cardiovascular involvement with thoracic and abdominal aortic aneurysms. It is noteworthy that the degree of the severity in the phenotype of one of our patients and another from the literature carrying a mutation in exon 41 could be explained with alterations in mRNA expression.

High prevalence of anti-beta2 glycoprotein I antibodies in patients with ischemic heart disease.

Ischemic cardiac manifestations have been reported in a various percentage of patients with anti-phospholipid antibodies. As concerns the relationship between anti-beta2 glycoprotein I antibodies (anti-beta2-GPI) and ischemic heart disease (IHD), it was investigated in only one coronary primary prevention study. We investigated the prevalence of anti-beta2-GPI in a well characterized group of patients with different clinical manifestation of IHD. Sera from 37 patients (mean age 62.7 +/- 9.9) with IHD (20 with unstable angina-UA and 17 with effort angina-EA) and from 40 healthy subjects, matched for age and sex, were tested for the presence of IgG and IgM anti-beta2-GPI using an ELISA technique. Eleven/37 patients (29.7%) resulted positive for anti-beta2-GPI. A positivity for IgG anti-beta2-GPI was found in 10 patients, 1 patient was positive for IgM and 1 for both isotypes. The prevalence of anti-beta2-GPI in the control group resulted significantly lower (2.5%; p < 0.005) than in patients with IHD. Positivity for anti-beta2-GPI was found in 9/20 (45%) patients with UA and only in 2/17 patients (11.8%) with EA (p = 0.0365). IgG anti-beta2-GPI levels (median 7.7U/ml, range 2.6-24.1) were significantly higher in patients with UA compared to patients with EA (median 4.6 U/ml, range 2.3-11.5; p = 0.02) and controls (median 3.15 U/ml, range 2.3-9.0; p < 0.0001); also IgM levels resulted higher in patients with unstable angina. A positivity for anti-beta2-GPI was observed in 4/13 patients (30.8%) with a previous myocardial infarction (MI) and in 7/24 (29.2%) patients without a previous MI. Our findings suggest that anti-beta2-GPI could represent an expression of the T-cell activation detectable in patients with unstable angina. The lack of a significant difference in the prevalence of these antibodies in patients with or without a previous MI suggests that anti-beta2-GPI are not induced by tissue necrosis.

Clinical application of fibrinolysis laboratory tests: a review.

The aim of this paper is to review fibrinolysis laboratory tests of potential clinical usefulness. Since the activation of the fibrinolytic system may be responsible for several relevant pathological scenarios, it is crucial to know whether and to what extent fibrinolysis laboratory tests are useful for the diagnosis and therapy of individual patients. The plasma fibrinolytic system may be altered by deficiencies and/or abnormalities of some of its components. Few doubts remain concerning the possible role of fibrinolysis alterations in the pathophysiology of some hemorrhagic and thrombotic disorders. In hemorrhagic patients, laboratory tests may demonstrate the existence of increased plasmin activity and the presence of specific congenital defects leading to primary hyperfibrinolysis. Alterations of the fibrinolytic system should be looked for only in selected patients who have a history of venous thrombosis and negative results of initial screening tests.

Effect of medium-term supplementation with a moderate dose of n-3 polyunsaturated fatty acids on blood pressure in mild hypertensive patients.

Several studies have shown that n-3 polyunsaturated fatty acids (n-3 PUFA) are able to lower blood pressure (BP) in humans, but large doses of fish oils have been often used. Moreover, most of the studies available in the literature were not able to evaluate the specific effects of n-3 PUFA because they employed fish oils which contain, together with n-3 PUFA, many other different components. The aim of this preliminary study was to evaluate if medium-term supplementation with a moderate dose of highly purified eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) ethyl esters is able to reduce BP in mild hypertensive patients. Sixteen mild essential hypertensive (diastolic BP: 95-104 mm Hg), non-diabetic, normolipidemic male outpatients and 16 normotensive male controls were recruited to participate in the study. Both hypertensive and control subjects were randomly assigned to receive either EPA and DHA ethyl esters (2.04 g EPA and 1.4 g DHA) as active treatment or olive oil (4 g/day) as a placebo for a period of 4 months. These subjects were followed up with 24-hour ambulatory BP monitoring and blood chemistry analyses at 2 and 4 months of treatment and 2 months after its discontinuation. The intake of n-3 PUFA was checked by red blood cell (RBC) phosphatidylcholine (PC) fatty acid composition. The effect of n-3 PUFA on BP in the active group was maximum after 2 months. Both systolic (-6 mm Hg, p<0.05) and diastolic (-5 mm Hg, p<0.05) BP significantly decreased during the n-3 PUFA ethyl ester supplementation. No further effect was observed at 4 months with a return to baseline values during the recovery period. These data indicate that 4 g/day of highly purified EPA + DHA ethyl esters are able to favorably affect BP in mild hypertensives.

A major involvement of the cardiovascular system in patients affected by Marfan syndrome: novel mutations in fibrillin 1 gene.

The aim of our study was to characterize the molecular defect in Italian Marfan patients, thus contributing to the effort of correlating the genotype with the phenotype. In particular, our ultimate goal was to identify the region(s) of the fibrillin 1 (FBN1) gene mainly involved in the health of the heart and of the aorta in terms of the cardiovascular system. We searched for a molecular defect in three patients with classic Marfan syndrome (MFS). The mutations were detected applying heteroduplex analysis to each of the 65 exons of the FBN1 gene amplified by polymerase chain reaction (PCR). Exons containing heteroduplex bands were sequenced directly from PCR products. This study reports the detection of three unique missense mutations in the FBN1 gene in three Italian patients: a 44-year-old adult male and 36-year-old female affected by classic MFS (with all the cardinal manifestations in the cardiovascular, ocular and skeletal systems), and an 11-year-old male affected by infantile (earlier onset) classic MFS. The first two are sporadic cases and present a Cys-->Arg amino acid substitution (T-->C substitution at nucleotide 7729) in exon 62 and a Cys-->Tyr amino acid substitution (G-->A substitution at nucleotide 6695) in exon 54. The third is a familial case which presents a Cys-->Trp aminoacidic substitution (C-->G substitution at nucleotide 3546) in exon 28. Our data confirm that cysteine substitutions in calcium binding epidermal growth factor (cbEGF)-like domains cause severe Marfan phenotype. Exon 24-32 cluster seems to produce an even more severe phenotype. The early characterization may be of clinical relevance for prevention and early surgical treatment of aortic aneurysm or dissection.