Hyperhomocysteinemia and the MTHFR C677T mutation in Budd-Chiari syndrome

Hyperhomocysteinemia (HH) is a factor that predisposes individuals to thrombosis, and the C677T mutation in the 5,10-methylenetetrahydrofolate reductase (MTHFR) is known to give increased plasma homocysteine. However, little is known about their roles in Budd-Chiari syndrome (BCS). This study evaluated the roles of HH and the MTHFR C677T mutation in patients with BCS. We compared 41 BCS patients with 80 sex- and age-matched healthy controls. The mean plasma homocysteine level was significantly higher in patients with BCS (20.15 +/- 5.78 micromol/L) compared with normal controls (15.80 +/- 6.58 micromol/L), P < 0.01. HH (>19.5 micromol/L in men and >15.0 micromol/L in women) was detected in 15 (36.59%) patients and in 14 (17.5%) controls (odds ratio [OR], 2.72; 95% confidence internal [CI], 1.17-6.32). The prevalence of the mutated MTHFR 677TT genotype and the 677T allele in normal controls was 10.0% and 31.3%, respectively. The mutant 677T homozygotes and alleles were more frequent in patients with BCS than in controls (22.0% vs. 10.0%, 0.025 < P < 0.05; 45.1% vs. 31.3%, 0.025 < P < 0.05). The relative risk of BCS among the carriers of 677TT was significantly increased (OR, 3.3; 95% CI, 1.1-10.0). The mutant MTHFR heterozygous 677C/T carriers were not significantly increased in patients with BCS compared with controls (46.3% vs. < 2.5%, P > 0.05). The relative risk OR of BCS among carriers of 677C/T was 1.6 (95% CI, 0.7-3.6). This study suggests that both HH and the homozygous C677T mutation in the MTHFR gene are important risk factors of BCS.     

Methylenetetrahydrofolate reductase C677T polymorphism and liver fibrosis progression in patients with recurrent hepatitis C

Background/Aims: Methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism, being a putative steatogenic factor, may promote liver fibrosis progression in patients with chronic hepatitis C. This study aimed to verify the role of recipient MTHFR polymorphism in favouring graft fibrosis progression in patients with recurrent HCV after orthotopic liver transplantation (OLT). Methods: We studied 63 such patients, followed for >1 year. MTHFR allelic variants were determined by a polymerase chain reaction/restriction fragment length polymorphism method. Results: Recipients carrying the TT genotype had more frequently, 1‐year post‐OLT, homocysteine serum levels >23 μmol/L (P<0.05), serum triglycerides >180 mg/dL (P<0.02) and de novo diabetes mellitus (P<0.05) but not a higher frequency of graft steatosis. Time‐to‐event analysis in reaching an Ishak staging score >2 was performed by stratifying the recipients as follows: (a) patients with donor age ≤45 years, (b) patients with donor age >45 and C/^* genotype, and (c) patients with donor age >45 years and TT genotype. A significant linear trend was observed, with increasing frequencies as follows: (a) 8/37, (b) 10/19 and (c) 6/7 (P=0.0005). Conclusion: The MTHFR C677T polymorphism may play a role in influencing liver fibrosis progression in patients with recurrent hepatitis C, in conjunction with donor age, but not via steatosis promotion.     

亚甲基四氢叶酸还原酶基因C677T多态性与HBV感染后疾病转归的关系

目的:探讨MTHFR C677T多态性对HBV感染后疾病转归的关系. 方法:采用TaqMan SNP基因分型和基因测序的方法检测152例健康对照人群、161例感染HBV后自愈者、173例慢性乙型肝炎患者、138例乙型肝炎肝硬化患者以及181例HBV相关性肝癌患者的MTHFR基因C677T位点的基因型及等位基因的分布及其差异. 结果:805例研究对象的基因型分布为CT基因型占47.09%、TT占30.43%、CC占22.48%;等位基因频率:C为46.02%,T为53.98%,此结果明显不同于以往报道.等位基因和基因型分布在各肝病组无统计学差异.分析不同性别在各组中的分布特征表明,男性患者TT在各组中显示风险降低,特别在肝硬化组TT和CT的OR值最低(与自愈组比较:0.675,95%CI:0.308-1.479;0.510,95%CI:0.248-1.050);而在女性的自愈、慢乙型肝炎和肝硬化组,TT和CT显示风险度增加,特别在肝硬化组OR值最高(与自愈组比较:3.542,95%CI:0.885-14.171;3.167,95%CI:0.821-12.211),具有统计学差异(P=0.022).同时,在女性肝癌组却显示风险度降低(0.638,95%CI:0.213-1.904;0.500,95%CI:0.175-1.432). 结论:本研究显示MTHFR C677T多态性在中国天津汉族人中显示了较高的TT基因型频率,同时提示MTHFR C677T多态性在HBV感染后疾病发展的过程中发挥重要作用.     

Factors associated with liver steatosis and fibrosis in chronic hepatitis C patients

Liver steatosis is a common finding in patients infected with hepatitis C virus (HCV). Host and viral factors have been associated with steatosis, but their relative contributions have not been clearly addressed. It has been suggested that steatosis plays a role in the progression of liver fibrosis. AIMS: To assess: a) factors associated with steatosis in patients infected with hepatitis C virus; b) their impact on liver fibrosis. PATIENTS AND METHODS: Three hundred and fourteen untreated patients were included. Lifetime alcohol consumption was estimated. Liver fibrosis, inflammation and necrosis were assessed using the METAVIR score. Body mass index (BMI) was determined. The scoring system for steatosis was as follows: 0, no steatosis; 1, less than 10%; 2, 10% to 30%; 3, 30% to 70%; 4, more than 70% of hepatocytes affected. RESULTS: In univariate analysis, steatosis was associated with elevated BMI (P=0.001), excessive alcohol intake (P=0.005), genotype 3 (P<0.001) and moderate to severe histological activity (P=0.01). Multivariate analysis showed that steatosis correlated with two independent factors: genotype 3a (OR=60.7; 95% CI: 7.6-483.4) (P<0.001) and BMI (OR=4.86; 95% CI: 1.8-13.15) (P=0.002). In univariate analysis, severe fibrosis (F2-F3-F4) was associated with older age (P<10(-5)), male gender (P=0.001), disease duration (P<0.006), BMI (P<10(-4)), alcohol intake (P<10(-6)), severity of histological activity (P<10(-5)) and steatosis (P<10(-6)). In multivariate analysis, three independent factors were associated with severe fibrosis: disease duration > 10 years (OR=3.17; 95% CI: 0.65-15.4) (P=0.015), presence of steatosis (OR=3.17; 95% CI: 1-9.99) (P<0.049) and genotype 3a (OR=5.56; 95% CI: 1.4-22.1) (P=0.015). CONCLUSION: In patients with chronic hepatitis C, steatosis is significantly associated with genotype 3 infection and high BMI. Steatosis is an independent risk factor associated with severe fibrosis. These results have major implications for the management of patients with chronic hepatitis C.     

MTHFR基因多态性与脑卒中的相关性

目的探讨河南豫北地区汉族脑卒中人群中N5,N10亚甲基四氢叶酸还原酶(MTHFR)基因C677T基因多态性。方法应用聚合酶链反应限制性片段长度多态性技术对151例脑卒中患者和151名健康对照人群进行HFR/C677T基因多态性分析,并对MTHFR/C677 T位点进行单倍型分析;同时检测两组同型半胱氨酸(Hcy)水平。结果两组FR/C677T基因型和等位基因频率有显著差异(P0.05),脑卒中组Hcy水平明显高于对照组(P0.05)。结论 MTHFR T/T基因型可能与脑卒中相关。     

Hepatic steatosis and fibrosis in chronic hepatitis C in Taiwan

Hepatitis C virus (HCV) infection has been associated with hepatic steatosis. However, the role of hepatic steatosis in the pathogenesis of HCV infection remains controversial. In our study, 425 consecutive HCV-viremic patients with biopsy-proven chronic hepatitis C (male, 264; mean age, 49.0 years) were enrolled. Scoring of hepatic steatosis was based on the method described by Kleiner and on histopathology performed using the Knodell and Scheuer systems. HCV RNA level and genotypes were determined at the time of biopsy. Hepatic steatosis was observed in 30.8% of patients, including 113 mild, 16 moderate, and 3 with severe hepatic steatosis. Patients with a body mass index (BMI) <23 kg/m(2) had a significantly lower rate (18.9%) of hepatic steatosis (P<0.001). Hepatic steatosis did not correlate with the hepatic necroinflammatory activity, but was related to hepatic fibrosis (P=0.035). Hepatic steatosis was also not associated with HCV RNA level, and the distribution was similar between patients with HCV genotype 1 and genotype 2 infection. According to multivariate analysis, BMI is the strongest risk factor associated with hepatic steatosis, followed by hepatic fibrosis and triglyceride level with odds ratios (95% confidence intervals) of 2.51 (1.49-4.23), 2.06 (1.14-3.70), and 1.02 (1.01-1.03), respectively. Hepatic steatosis was associated with being overweight, hepatic fibrosis, and triglyceride level in chronic hepatitis C.     

C677T gene polymorphism of methylenetetrahydrofolate reductase (MTHFR) in patients with myocardial infarction

Hyperhomocysteinemia is thought to be an independent risk factor for coronary heart disease. Increased plasma homocysteine level can result from malnutrition (e.g. folate deficiency) and/or genetic-related disturbances. Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme in the synthesis of 5-methyltetrahydrofolate, the methyl donor for homocysteine remethylation to methionine. Transition of cytosine (C) to thymidine (T) at nucleotide position 677 of MTHFR gene causes alanine 226-to-valine substitution, and in consequence results in decreased enzyme activity and increased homocysteine level. Therefore, the aim of our study was to estimate the frequency distribution of C677T MTHFR polymorphism in patients with past myocardial infarction (MI), and to evaluate the association between this polymorphism and age of MI onset or left ventricular mass (LVM). The study was performed in 100 MI patients aged from 34 to 76 years and in control group consisted of 100 age- and gender-matched non-MI subjects. Applying PCR followed by Hinf I digestion of amplification products no significant difference in the frequency distribution of C677T MTHFR genotypes has been found between both groups (MI patients: 46% CC, 45% CT and 9% TT, and control group: 39% CC, 50% CT and 11% TT, respectively). No significant association between MTHFR genotypes and age of MI onset or LVM has been found in MI group. The results of our study suggest that C677T polymorphism of MTHFR gene is not a risk factor for myocardial infarction in Polish population.     

Connective tissue growth factor,steatosis and fibrosis in patients with chronic hepatitis C

Background/Aim: Both steatosis and insulin resistance have been linked to accelerated fibrosis in chronic hepatitis C. Connective tissue growth factor (CTGF) plays a major role in extracellular matrix production in fibrotic disorders including cirrhosis, and its expression is stimulated in vitro by insulin and glucose. We hypothesized that CTGF may link steatosis, insulin resistance and fibrosis. Methods: We included 153 chronic hepatitis C patients enrolled in the Swiss Hepatitis C Cohort Study and for whom a liver biopsy and plasma samples were available. CTGF expression was assessed quantitatively by immunohistochemistry. In 94 patients (57 with genotypes non‐3), plasma levels of glucose, insulin and leptin were also measured. CTGF synthesis was investigated by immunoblotting on LX‐2 stellate cells. Results: Connective tissue growth factor expression was higher in patients with steatosis (P=0.039) and in patients with fibrosis (P=0.008) than those without these features. CTGF levels were neither associated with insulinaemia or with glycaemia, nor with inflammation. By multiple regression analysis, CTGF levels were independently associated with steatosis, a past history of alcohol abuse, plasma leptin and HCV RNA levels; when only patients with genotypes non‐3 were considered, CTGF levels were independently associated with a past history of alcohol abuse, plasma leptin levels and steatosis. Leptin stimulated CTGF synthesis in LX‐2 cells. Conclusions: In patients with chronic hepatitis C and steatosis, CTGF may promote fibrosis independently of inflammation. CTGF may link steatosis and fibrosis via increased leptin levels.     

Cryoglobulinemia is associated with steatosis and fibrosis in chronic hepatitis C

The relationship between cryoglobulin and severity of liver lesions is debated. No study has focused on the relationship between cryoglobulin, liver steatosis, and fibrosis. The aim of this study was to determine the relationship between cryoglobulins and liver lesions (necroinflammation, fibrosis, and steatosis) in patients with hepatitis C virus (HCV) infection. Four hundred and thirty-seven consecutive patients with untreated chronic hepatitis C who had been admitted for liver biopsy were included in the study. Risk factors for fibrosis and steatosis were assessed. The mean age was 50.9 +/- 13.8 years, and 49% were male. Cryoglobulin was present in 286 patients, 103 of whom had vasculitis. One hundred and eighty-six patients (43%) had steatosis greater than 10%, and 110 (25%) had advanced fibrosis (Metavir score F3-F4). On multivariate analysis, cryoglobulin increased by nearly threefold the risk of having advanced fibrosis and steatosis greater than 10%. Steatosis greater than 10% was associated with a higher body mass index (P < .001), HCV genotype 3 (P < .001), cryoglobulin (P = .002), and advanced liver fibrosis (P = .009). Advanced fibrosis (F3-F4) was associated with a higher level of gamma-glutamyltransferase (P = .04), cryoglobulin (P < .001), a high grade of necroinflammation (Metavir score A2-A3) (P < .001), and steatosis higher than 10% (P = .04). In conclusion, our study shows an independent association between cryoglobulin and steatosis as well as advanced fibrosis.     

Lack of association between the MTHFR (C677T) polymorphism and atopic disease

Background: Impaired folate metabolism has been suggested as a potential risk factor for the development of asthma and atopic disease. However, there have been conflicting reports on the potential association between atopic disease and a common polymorphism of the methylene‐tetrahydrofolate reductase (MTHFR)‐gene, a well‐known marker of impaired folate metabolism. Objectives: The aim of this study was to investigate the association between the MTHFR (C677T) polymorphism and different outcome variables of asthma and atopic disease. Methods: This study was a population‐based study of 1189 participants aged 15–77 years living in Copenhagen, the Capital of Denmark. Examinations included measurements of specific IgE and skin prick tests against inhalant allergens, metacholine bronchial hyper‐reactivity, and serum eosinophilic cationic protein, and a self‐administered questionnaire about diagnoses and symptoms of allergy and asthma. In addition, participants were genotyped for the MTHFR (C677T) polymorphism. Results: None of the examined outcomes were significantly associated with the MTHFR (C677T) polymorphism. Conclusions: The results of this study using detailed objective markers of atopic disease do not support the hypothesis that impaired folate metabolism as reflected by the MTHFR genotype is involved in the development of atopic disease. Please cite this paper as: Thuesen BH, Husemoen LLN, Fenger M and Linneberg A. Lack of association between the MTHFR (C677T) polymorphism and atopic disease. The Clinical Respiratory Journal 2009; 3: 102–108.     

The methylenetethrahydrofolate reductase (MTHFR) C677T polymorphism and male infertility in Italy

The 677T allele of the MTHFR gene has been suggested to represent a factor of risk for male infertility. In order to confirm this association, we investigated the presence of the 677T allele in 93 Italian infertile patients, selected after the exclusion of other possible genetic causes of infertility, and in 105 Italian fertile controls. The homozygous 677TT genotype was present in 20.4% of patients and 27.6% of controls. These results do not support an association between the MTHFR 677T allele and male infertility in Italy.     

Effect of steatosis and inflammation on liver fibrosis in chronic hepatitis C

Background/Aims: The role of liver biopsy has been questioned in the management of patients with hepatitis C viral (HCV) infection. The aims of this study were to determine the impact of clinical parameters and degree of inflammation and steatosis on liver fibrosis. Patients/Methods: Clinical data and liver histology findings in 510 HCV patients were analysed. Results: Hepatitis C virus genotype 1 (GT‐1) was found in 38%, GT‐2 in 15% and GT‐3 in 45% of patients. In liver biopsy specimens, inflammation activity was present in 68%, increased fibrosis in 19% and marked steatosis in 17% of patients. Independent clinical risk factors for the increased fibrosis were patients' age at biopsy, body mass index (BMI) and duration of HCV. Steatosis and inflammation activity were independent histological risk factors for fibrosis only in GT‐1; in GT‐3, only inflammation correlated independently with fibrosis. Conclusions: Age at liver biopsy, BMI and duration of HCV were independent risk factors for increased fibrosis in HCV patients. Steatosis as a risk factor for fibrosis is evident in GT‐1. When scoring liver biopsies of HCV patients, the degree of steatosis should be included in addition to fibrosis and inflammation activity.     

MTHFR C677T基因多态性与冠心病患者同型半胱氨酸及冠脉狭窄程度的相关性

[摘 要] 目的 探讨MTHFR C677T基因多态性与河南中部汉族冠心病（CHD）患者同型半胱氨酸(Hcy)及冠脉狭窄程度的相关性。方法 应用荧光染色原位杂交技术对河南中部汉族352例CHD患者和340例非CHD对照者进行MTHFR C677T基因多态性检测,并比较两组不同基因型之间Hcy水平的差异。采用Gensini评分系统评价CHD患者的冠脉狭窄程度,多元线性回归分析法探讨MTHFR C677T基因多态性以及其他因素与Gensini得分之间的相关性。结果 非CHD组MTHFR C677T 基因CC、CT、TT 型例数及分布频率分别为113(33.2％)、159(46.8％)、68(20％),CHD组MTHFR C677T位点CC、CT、TT型例数及分布频率分别为85(24.1％)、157(44.6％)、110(31.3％)。两组受试者各基因型分布频率均符合Hardy-Weinberg 平衡（P＞0.05）。两组受试者MTHFR C677T各基因型分布频率及等位基因频率比较,差异均有统计学意义（P＜0.001）。CHD组血清Hcy水平、高血压、糖尿病患病率分别为（23.1±8.7）、27.8%和16.8%,均高于非CHD组的（18.6±7.4）、10.6%和6.2%,差异均有统计学意义（P <0.05）。两组不同基因型之间血清Hcy水平差异有统计学意义（P <0.05）。多元线性回归分析结果显示,MTHFR C677T基因多态性与Gensini得分的相关性无统计学意义（β=-0.16,95%CI：-0.21～0.18,P=0.785）。结论MTHFR C677T基因多态性影响Hcy水平,但与CHD患者冠脉狭窄程度无明显相关性。     

Relationship between genetic polymorphism of MTHFR C677T and lower extremities deep venous thrombosis

Objective: To investigate the association between the polymorphism of methylenetetrahydrofolate reductase (MTHFR) gene and the formation of lower extremities deep venous thrombosis, and to evaluate the etiology of deep venous thrombosis.

Methods: Polymorphisms of the 677th site C/T in MTHFR gene for 101 patients with lower extremities deep venous thrombosis (DVT group) and 120 healthy subjects (control group) were detected by polymerase chain reaction with sequence-specific primers. Genotype and allelic frequencies were compared between the two groups.

Results: Genotype frequencies of CC, CT and TT in MTHFR C677?T were 41.58, 25.74 and 32.67% in DVT group, and 58.33, 23.33 and 18.33% in control group, respectively. There was a significant difference in TT genotype frequency between the two groups (P <0.05).

Conclusion: The frequency of MTHFR 677TT genotype may be correlated with the morbility of DVT.