VDBP, CYP27B1, and 25-Hydroxyvitamin D Gene Polymorphism Analyses in a Group of Sicilian Multiple Sclerosis Patients.

Multiple sclerosis (MS) is a chronic demyelinating disease of central nervous system regarded as one of the most common causes of neurological disability in young adults. The exact etiology of MS is not yet known, although epidemiological data indicate that both genetic susceptibility and environmental exposure are involved. A poor vitamin D status has been proposed as the most attractive environmental factor. Several evidence have highlighted the importance of mutations in vitamin D-regulating genes for vitamin D status. The purpose of our study was to assess the genetic variants of VDBP and CYP27B1 in MS patients and in a control group. A total of 192 subjects, including 100 MS patients and 92 healthy controls, were genotyped by polymerase chain reaction followed by restriction fragment length polymorphism analyses. Serum 25-hydroxyvitamin D levels were measured in MS patients and controls by high-performance liquid chromatography. We did not observe any statically significant difference in the distribution of genotypic VDBP variants between the study groups. 25(OH)D plasma levels were significantly higher in the control group versus MS patients; MS patients who carried Gc2 showed lower 25(OH)D plasma levels and those who carried Gc1f showed higher levels. We observed only wild-type allele for CYP27B1 mutations analyzed both in MS patients and in the control group. In conclusion, our findings do not support a role of an independent effect of the investigated vitamin D-related gene variants, VDBP and CYP27B1, in the risk of MS.

Vitamin D receptor polymorphisms and 25-hydroxyvitamin D in a group of Sicilian multiple sclerosis patients.

Multiple sclerosis (MS) is an auto-immune disease whose etiology remains controversial. Both genetic and environmental factors are thought to be involved in the risk of developing the disease. The purpose of our study was to assess the association of Vitamin D receptor (VDR) polymorphisms with MS and to investigate the interaction of these polymorphisms with vitamin D levels. A total of 179 Sicilian subjects, including 104 MS patients and 75 healthy controls, were studied. The most common VDR polymorphisms (Fok-I, Bsm-I, Taq-I and Apa-I) were genotyped by polymerase chain reaction (PCR) followed by restriction fragment length polymorphism (RFLP) analyses in both groups and serum 25-hydroxyvitamin D [25(OH)D] levels were determined in MS patients by high-performance liquid chromatography (HPLC). The distribution of genotype and allele frequencies of the four VDR polymorphisms did not differ significantly between MS patients and healthy controls, and were unrelated to the forms and the course of MS. Low serum levels of 25(OH)D were observed in MS patients but no association was observed between VDR and 25(OH)D levels except for Fok-I. Moreover, MS patients with FF and Ff genotype had a significantly lower serum levels of 25(OH)D compared with ff carriers (P < 0.05 FF vs Ff and Ff vs ff). Our findings showed no association between VDR polymorphisms and risk of MS. Interestingly, F allele could confer a genetic predisposition to lower 25(OH)D levels.

Vitamin D receptor gene polymorphisms and plasma renin activity in essential hypertensive individuals.

Several studies analyzed 25-hydroxyvitamin D (25[OH]D) and blood pressure (BP) relationship with mixed results. Moreover, a relationship between the risk of hypertension and vitamin D receptor (VDR) gene polymorphisms, FokI and BsmI, was reported. This study was aimed to analyze these relationships in essential hypertensive (EH) patients. Seventy-one EH patients, 18-75 years old, were enrolled. Patients underwent clinical BP, 24-h ambulatory BP monitoring, 25[OH]D and plasma renin activity (PRA) evaluations. FokI and BsmI VDR polymorphisms were analyzed and compared with those of 72 healthy controls. In EH patients, the median 25[OH]D levels were lower than 30 ng ml(-1). We found a significant negative correlation between 25[OH]D and 24-h systolic BP (r = -0.277, P = 0.043). This correlation persisted in backward stepwise multivariate analyses (ß = -0.337; P = 0.022), after adjustment for age, gender, body mass index, glomerular filtration rate, and PRA. We did not observe statistically significant correlation between 25[OH]D and PRA. We compared the allelic frequencies and genotype distribution between patients and controls, and FokI and BsmI VDR polymorphisms were not associated either with hypertensive status or with PRA. Further wide studies are needed to clarify this relationship.

Correlation between low folate levels and hyperhomocysteinemia, but not with vitamin B12 in hypertensive patients.

INTRODUCTION: Hypertension is considered to be among the most important risk factors for cardiovascular and cerebrovascular diseases. In recent years, several investigators have reported that high plasma levels of total homocysteine (t-hcy) has a key role in the development of hypertension, and the deficiency of B complex vitamins could increase the risk of hypertension. The purpose of this study was to investigate the relationship between plasma homocysteine, folate and vitamin B12 in hypertensive patients. MATERIALS AND METHODS: In 116 patients with hypertension and 81 healthy subjects, total plasma homocysteine, vitamin B12 and folate levels were measured. RESULTS AND DISCUSSION: Homocysteine was significantly higher in patients than in control subjects (22.9±3.5 versus 9.0±2.3 µmol/L respectively, p<0.001); the folate plasma concentrations in hypertensive patients were significantly lower than in control subjects (6.7±5.0 ng/ml and 9.0±4.4 ng/ml respectively, p<0.05). Moreover, no differences in vitamin B12 plasma levels were observed when comparing the levels of hypertensive patients and those of the controls (440±223 pg/ml vs 491±185 pg/ml respectively, p>0.05). Our results confirmed that, as previously observed, elevated t-hcy levels and low folate levels, but not vitamin B12 levels, are significantly associated with hypertension.

Association of vitamin D serum levels and its common genetic determinants, with severity of liver fibrosis in genotype 1 chronic hepatitis C patients.

Lower 25-hydroxyvitamin D [25(OH)D] serum levels have been associated with the severity of liver fibrosis in genotype 1 chronic hepatitis C patients (G1CHC). In addition, a recent genome-wide study identified genetic variants (rs12785878, near dehydrocholesterol reductase, DHCR7; rs10741657, near CYP2R1; and rs7041, near vitamin D-binding protein, GC) affecting 25(OH)D serum levels in healthy populations. We aimed to assess the association between vitamin D serum levels and its genetic determinants, with the severity of liver fibrosis. Two hundred and sixty patients with biopsy-proven G1CHC were consecutively evaluated. The 25(OH)D serum levels were measured by high-pressure liquid chromatography. All patients were genotyped for DHCR7 rs12785878, CYP2R1 rs10741657 and GC rs7041 single nucleotide polymorphisms. DHCR7 GG genotype (P = 0.003) and the severity of fibrosis (P = 0.03) were independent factors associated with lower 25(OH)D serum levels in multiple linear regression analysis. Interestingly, 53.8% (7/13) of patients with DHCR7 GG genotype had severe liver fibrosis, compared to 27.1% (67/247) of those with DHCR7 TT/TG genotype (P = 0.03). By multivariate logistic regression analysis, severe fibrosis was independently associated with older age (OR, 1.056; 95% CI, 1.023-1.089, P = 0.001), low cholesterol (OR, 0.984; 95% CI, 0.974-0.994, P = 0.002), high triglycerides (OR, 1.008; 95% CI, 1.002-1.015, P = 0.01), low 25(OH)D (OR, 0.958; 95% CI, 0.919-0.999, P = 0.04), DHCR7 GG genotype (OR, 4.222; 95% CI, 1.106-16.120; P = 0.03), moderate-severe steatosis (OR, 2.588; 95% CI, 1.355-4.943; P = 0.004) and moderate-severe necroinflammatory activity (grading) (OR, 2.437; 95% CI, 1.307-4.763; P = 0.001). No associations were found between liver fibrosis and both CYP2R1 and GC genotypes. In patients with G1CHC, GG homozygosis for DHCR7 gene and lower 25(OH)D levels are independently associated with the severity of liver fibrosis.

Methionine synthase reductase (MTRR) A66G polymorphism is not related to plasma homocysteine concentration and the risk for vascular disease.

Epidemiological evidence has revealed that hyperhomocysteinemia increases the risk for vascular disease. Methionine Synthase Reductase (MTRR) is one of several key enzymes in the homocysteine metabolic pathway and its mutant forms have been implicated in abnormal homocysteine accumulation. In this study, we determined total plasma homocysteine levels and MTRR A66G polymorphism in 114 patients with vascular disease: 58 patients with deep-vein thrombosis, 56 patients with arterial thrombosis, and 95 healthy subjects from the Sicilian population. Our data confirmed that, as already reported, moderately elevated t-Hcy levels are correlated with an increased risk of vascular disease. In our study, the levels of t-Hcy found in both deep-vein thrombosis (13.7+/-3.2 micromol/L) and arterial thrombosis (14.3+/-4.3 micromol/L) patient groups were higher than levels detected in normal subjects (8.7+/-2.7 micromol/L). We concluded that the MTRR A66G polymorphism was not associated with the t-Hcy plasma concentration because the same genotype frequency distribution was detected in both patients and healthy individuals.

Quantitative evaluation of oxidative stress status on peripheral blood in beta-thalassaemic patients by means of electron paramagnetic resonance spectroscopy.

High oxidative stress status (OSS) is known to be one of the most important factors determining cell injury and consequent organ damage in thalassaemic patients with secondary iron overload. Using an innovative hydroxylamine 'radical probe' capable of efficiently trapping majority of oxygen-radicals including superoxide we measured, by electron paramagnetic resonance (EPR) spectroscopy, OSS in peripheral blood of 38 thalassaemic patients compared with sex-/age-matched healthy controls. Thalassaemic patients showed sixfold higher EPR values of OSS than controls. Significantly higher EPR values of OSS were observed in those with a severe phenotype (thalassaemia major, transfusion-dependent) with respect to mild phenotype (sickle-cell/beta-thalassaemia, not transfusion-dependent) or thalassaemia intermedia. In patients with thalassaemia major, EPR values of OSS were positively correlated with serum ferritin and with alanine aminotransferase levels. In patients with sickle cell/beta-thalassaemia, there was no correlation between EPR value of OSS and all parameters considered. The type of chelating therapy (desferrioxamine or deferiprone) did not have an effect on EPR value of OSS. In conclusion, EPR 'radical probe' seems to be a valid innovative method to determine total OSS in patients affected by thalassaemia and might be used for evaluating new strategies of chelation, new chelators, or the efficacy of antioxidant formula.