The relation of fibrosis stage with nutritional deficiencies and bioelectrical impedance analysis of body composition in patients with chronic hepatitis C.

UNLABELLED:  Background. Nutritional deficiencies may aggravate the course of chronic hepatitis C (CHC). Our aim has been to perform a comprehensive analysis of body composition and nutritional deficiencies in CHC patients in non-cirrhotic and compensated cirrhotic stages to correlate the detected deficiencies with the fibrosis stage. MATERIAL AND METHODS: Body multifrequency bioimpedance analysis (BIA) and a wide and simultaneous analytical profile were prospectively performed in 74 CHC patients (36 male) with known METAVIR fibrosis stage established with liver biopsy or transient elastography. Results were analyzed to identify deviations from the normal range and variations according to the fibrosis stage. RESULTS: Body fat compartment was greater in women. Body composition did not change among the 4 stages of liver fibrosis. Low levels (< 30 µg/L) of vitamin D were detected in 74.3% of patients irrespective of the fibrosis stage. Most analytical results remained into the normal range with the exceptions of thrombocytopenia and vitamin A deficiency, that were limited to the stage 4 of fibrosis, and low Zn and LDL-cholesterol values, that were frequently found in patients with advanced (F3 and F4) fibrosis stage. CONCLUSION: Body composition and most biochemical parameters, including cyanocobalamin, folic acid and vitamin E, are well preserved in compensated patients with CHC, with the exception of generalized vitamin D insufficiency and of deficiencies of vitamin A and zinc that are restricted to the more advanced, although still compensated, stages of the disease.

GC Gene Polymorphism and Unbound Serum Retinol-Binding Protein 4 Are Related to the Risk of Insulin Resistance in Patients With Chronic Hepatitis C: A Prospective Cross-Sectional Study.

Insulin resistance (IR) is found in chronic hepatitis C (CHC) more frequently than in other chronic liver diseases.Prospective cross-sectional study to evaluate a wide multitest panel to identify factors related with IR in CHC and their possible interactions.In 76 patients with CHC we performed a series of routine laboratory analysis as well as specifically designed serum biochemical tests [retinol, retinol-binding protein 4 (RBP4), 25-OH vitamin D, Vitamin E, lipopolysaccharide-binding protein (LBP), interleukin-6 (IL-6), and cystatin C]. The single nucleotide polymorphisms rs7041 and rs4588 GC-DBP (group-specific component-Vitamin D-binding protein), rs738409 PNPLA3 (patatin-like phospholipase domain containing 3), and rs12979860 IL28B (interleukin-28 B) genes were determined. Insulin sensitivity was established with the HOMA-IR and IR was diagnosed when HOMA-IR > 3. Fibrosis staging was assessed with liver biopsy or transient elastography.After backward logistic regression analysis, independent variables associated with IR were Gc1s/Gc1s DBP phenotype, that results from the homozygous carriage of the rs7041G/rs4588C haplotype (P = 0.033); low retinol/RBP4 ratio, reflecting a greater rate of unbound RBP4 (P = 0.005); older age (P = 0.01); high serum tryglicerides (P = 0.026); and advanced (F3-F4) fibrosis stage. The AUROC provided by the multivariate model was 0.950 (95% CI = 0.906-0.993).In addition to previously known ones, the Gc1s/Gc1s phenotype variant of DBP and the unbound fraction of plasma RBP4 may be considered as factors related with the incidence, and possibly the risk, of IR in CHC patients.

Matrix metalloproteinase 10 contributes to hepatocarcinogenesis in a novel crosstalk with the stromal derived factor 1/C-X-C chemokine receptor 4 axis.

UNLABELLED: Matrix metalloproteinases (MMPs) participate in tissue repair after acute injury, but also participate in cancer by promoting a protumorigenic microenvironment. Previously, we reported on a key role for MMP10 in mouse liver regeneration. Herein, we investigated MMP10 expression and function in human hepatocellular carcinoma (HCC) and diethylnitrosamine (DEN)-induced mouse hepatocarcinogenesis. MMP10 was induced in human and murine HCC tissues and cells. MMP10-deficient mice showed less HCC incidence, smaller histological lesions, reduced tumor vascularization, and less lung metastases. Importantly, expression of the protumorigenic, C-X-C chemokine receptor-4 (CXCR4), was reduced in DEN-induced MMP10-deficient mice livers. Human HCC cells stably expressing MMP10 had increased CXCR4 expression and migratory capacity. Pharmacological inhibition of CXCR4 significantly reduced MMP10-stimulated HCC cell migration. Furthermore, MMP10 expression in HCC cells was induced by hypoxia and the CXCR4 ligand, stromal-derived factor-1 (SDF1), through the extracellular signal-regulated kinase 1/2 pathway, involving an activator protein 1 site in MMP10 gene promoter. CONCLUSION: MMP10 contributes to HCC development, participating in tumor angiogenesis, growth, and dissemination. We identified a new reciprocal crosstalk between MMP10 and the CXCR4/SDF1 axis contributing to HCC progression and metastasis. To our knowledge, this is the first report addressing the role of a MMP in hepatocarcinogenesis in the corresponding genetic mouse model.

Influence of vitamin D-related gene polymorphisms (CYP27B and VDR) on the response to interferon/ribavirin therapy in chronic hepatitis C.

BACKGROUND AND AIMS: Vitamin D exerts immunomodulatory effects on the host response against infection with hepatitis C virus (HCV). This study was performed to assess the putative influence of polymorphisms in vitamin D-related genes on the response to antiviral therapy in patients with chronic hepatitis C (CHC). METHODS: Single nucleotide polymorphisms (SNPs) in CYP27B-1260 gene promoter (rs10877012AC) and in vitamin D receptor (VDR) gene rs2228570TC, rs1544410CT, rs7975232AC and rs731236AT were analyzed in a cohort of 238 Caucasian CHC patients treated with pegylated interferon (Peg-IFN) plus ribavirin (RBV). Multivariate analyses were performed to exclude confounding effects of well-known baseline predictors of response to therapy (HCV genotype and load, IL28B genotype, age, and GGT and serum cholesterol). RESULTS: Three SNPs at the VDR gene (rs1544410, rs7975232 and rs731236) were in strong linkage disequilibrium, with the CCA haplotype predicting therapeutic failure [Odds ratio 2.743; (95% C.I. 1.313-5.731), p = 0.007]. The carrier state of the VDR rs2228570 T allele was inversely related to the probability of therapeutic failure [Odds ratio 0.438; 95 C.I. (0.204-0.882), p = 0.021]. No relation existed between CYP27B-1260 rs10877012 polymorphism and response to therapy. The area under the operating curve (AUROC) based on the model including all variables significantly related to the response to therapy was 0.846 (95% confidence interval = 0.793-0.899). CONCLUSION: VDR gene polymorphisms are independently related to the response to Peg-IFN+RBV therapy in chronic hepatitis C and could be used as complementary biomarkers of response when included in a prediction algorithm in association with demographic, virologic, biochemical and genetic traits.

Vitamin D deficiency and vitamin D therapy in chronic hepatitis C.

BACKGROUND: Vitamin D has immunomodulatory properties, exerts an anti-hepatitis C virus (HCV) effect in vitro and improves response to interferon-based therapy in patients with chronic hepatitis C (CHC). Low serum levels of 25(OH) vitamin D [25(OH)D] are frequently found in CHC patients and seem to be related to more advanced stages of liver fibrosis. The study aims to establish the incidence of vitamin D deficiency in Spanish patients with CHC, its possible relation with features of liver damage and with the IL28B gene polymorphism, and the immediate effect of vitamin D therapy on CHC-related analytical variables. MATERIALS AND METHODS: Baseline serum 25(OH)D levels were measured in 108 consecutive CHC patients (60 men, age 54.3 ± 10.5 yrs). Results of transient elastography and of IL28B rs12979860C/T genotype were available in 89 and 95 patients, respectively. Forty one patients with insufficient levels of 25(OH)D received vitamin D supplements and were re-evaluated thereafter. RESULTS: Deficiency of vitamin D (< 20 µg/dL) and suboptimal levels (20-30 µg/mL) were detected in 36.1% and 40.9% of patients, respectively. No relationships were found between 25(OH)D levels and biochemical liver tests, fibrosis stage and IL28B genotype. Vitamin D therapy normalized 25(OH)D levels in all treated patients, but did not modify significantly HCV-RNA serum levels or biochemical tests. CONCLUSIONS: Vitamin D deficiency is common in Spanish patients with CHC but it is related neither to biochemical and virological variables nor with the fibrosis stage and IL28B polymorphism. Vitamin D therapy has no immediate effect on HCV-RNA serum levels.

Serum cystatin C: a non-invasive marker of liver fibrosis or of current liver fibrogenesis in chronic hepatitis C? .

BACKGROUND: Serum levels of cystatin C, an endogenous inhibitor of cysteine proteases, provide an alternative method to creatinine-based criteria for measuring glomerular filtration rate. Preliminary data suggested that serum cystatin C levels parallel with the stage of liver fibrosis in chronic liver disorders. Our aim has been to evaluate the possible role of serum cystatin C as a marker of liver fibrosis in hepatitis C virus (HCV)-induced chronic liver disease. MATERIAL AND METHODS: 100 consecutive patients (56 men, mean age 51.2 ± 9.5 yrs) with HCV-induced chronic liver disease, scheduled for their first liver biopsy and naïve for antiviral therapy were included. Liver fibrosis was evaluated with the METAVIR score. Serum cystatin C and standard laboratory tests were measured simultaneously. Patients with ethanol abuse (> 50 g/day), HBV or HIV coinfection or plasma creatinine ≥ 1.20 mg/dL were excluded. In addition, a second group of 16 patients fulfilling the same requisites and diagnosed with HCV-induced compensated cirrhosis by clinical evidence of portal hypertension was included. RESULTS: Serum cystatin C levels significantly increase from F0 to F2 fibrosis stages, remained stable in F3 and F4 stages and increased again in the group of non-biopsied compensated cirrhosis. Serum cystatin C levels were higher in patients with moderate-advanced necroinflammation in the liver biopsy. CONCLUSION: Serum cystatin C level may reflect current fibrogenic and necroinflammatory activities in chronic HCV-induced liver disease with normal renal function but can not be considered as a non-invasive marker of liver fibrosis.

Relation of IL28B gene polymorphism with biochemical and histological features in hepatitis C virus-induced liver disease.

BACKGROUND/AIMS: Polymorphism at the IL28B gene may modify the course of hepatitis C virus (HCV) chronic infection. Our aim was to study the influence of IL28B rs12979860 gene polymorphism on the biochemistry and pathology of HCV-induced disease in the clinical course from mild chronic hepatitis C to hepatocellular carcinoma. METHODS: We have determined the rs12979860 single nucleotide polymorphism (SNP) upstream IL28B gene in two groups of patients with HCV-induced chronic liver disease: 1) 268 patients (159 men) with biopsy-proven chronic hepatitis C, to analyse its relation with biochemical, virological and histological features; and 2) 134 patients (97 men) with HCV-related hepatocellular carcinoma. The distribution of the analysed SNP in hepatocellular carcinoma patients was compared with that found in untreated chronic hepatitis C patients. All patients were white and most were Spaniards. RESULTS: In multivariate analysis ALT values were higher (P = 0.001) and GGT values were lower (P<0.001) in chronic hepatitis C patients homozygotes for the major rs12979860C allele as compared with carriers of the mutated rs12979860T allele. Steatosis was more frequent (Odds ratio = 1.764, 95% C.I. 1.053-2.955) and severe (P = 0.026) in carriers of the rs12979860T allele. No relation was found between the analysed SNP and METAVIR scores for necroinflammation and fibrosis, and there were no differences in the distribution of the analysed SNP between hepatocellular carcinoma and untreated chronic hepatitis C patients. CONCLUSION: The IL28B rs12979860 polymorphism correlates with the biochemical activity and the presence and severity of liver steatosis in chronic hepatitis C.

Polymorphism of the TLR4 gene reduces the risk of hepatitis C virus-induced hepatocellular carcinoma.

OBJECTIVE: Toll-like receptor 4 (TLR4) signalling participates in the innate immune response against hepatitis C virus (HCV) infection. TLR4 gene polymorphisms may influence the risk of HCV-induced hepatocellular carcinoma (HCC). This is a single-centre-based study designed to analyse the distribution of several TLR4 gene single nucleotide polymorphisms in healthy controls and in patients chronically infected with HCV, with and without HCC. METHODS: We have determined three single nucleotide polymorphisms (rs2149356, rs4986791 and rs5030719) at the TLR4 gene in 155 patients with HCV-related HCC, 153 patients with chronic hepatitis C and 390 healthy controls. All were white and most were Spaniards. RESULTS: (1) rs5030719 was monomorphic and was not further analysed; (2) the rs2149356 T allele carrier state was significantly less frequent in patients with HCC than in healthy controls (OR 0.421, 95% CI 0.285-0.625) and in patients with chronic hepatitis C (OR 0.426, 95% CI 0.236-0.767); (3) the proportion of rs2149356 T allele carriers progressively diminished with increasing clinical stage of HCC; (4) no significant differences were observed for the rs4986791 T allele. CONCLUSION: The TLR4 rs2148356 T allele is associated with a reduced risk of HCC and could slow down its clinical progression in HCV-induced chronic liver disease.

Predicting response to therapy in chronic hepatitis C: an approach combining interleukin-28B gene polymorphisms and clinical data.

BACKGROUND AND AIM: Polymorphisms at the interleukin-28B (IL28B) gene predict therapeutic response in chronic hepatitis C virus genotype 1 (CHC-1) infection. The aim of the present study was to establish whether a unique single-nucleotide polymorphism (SNP) represents the whole predictive value of the IL28B haplotype for sustained viral response (SVR) and primary non-response (PNR). METHODS: SNP rs12979860 and rs8099917 were determined by TaqMan assays in 110 CHC-1 Caucasian patients treated with pegylated interferon plus ribavirin. RESULTS: There were 51 SVR, 43 PNR, and 16 relapses. Baseline predictors of SVR were rs12979860CC genotype (P = 0.008), viral load < 400.000 IU/mL (P < 0.010), age (P = 0.013), γ-glutamyl transferase (P = 0.022), alkaline phosphatase (P = 0.008), and cholesterol (P = 0.048). The area under the receiver-operating curve (AUROC) of the model, including these variables, was 0.841 (95% confidence interval [CI] = 0.767-0.916). The same figures for PNR were rs12979860 T-allele carrier state (P = 0.00008), viral load ≥ 400.000 IU/mL (P = 0.007), aspartate aminotransferase/alanine aminotransferase (P = 0.048), and serum cholesterol (P = 0.064), (AUROC = 0.869, 95% CI = 0.792-0.945). After excluding rs12979860CT SNP from multivariate analyses, the rs8099917 genotype alone did not predict SVR (P = 0.185), but strongly predicted PNR (P = 0.003). The significance of haplotypes combining both SNP as predictors of SVR and PNR was higher than those of each separate SNP. CONCLUSIONS: The rs12979860 SNP strongly predicts therapeutic response in CHC-1 patients, and if associated with easy-to-obtain baseline criteria, provides a useful tool for the selection of candidates for antiviral therapy. IL28B haplotypes might improve the clinical usefulness of individual SNP.

Analysis of the Functional Polymorphism in the Cytochrome P450 CYP2C8 Gene rs11572080 with Regard to Colorectal Cancer Risk.

In addition to the known effects on drug metabolism and response, functional polymorphisms of genes coding for xenobiotic-metabolizing enzymes (XME) play a role in cancer. Genes coding for XME act as low-penetrance genes and confer modest but consistent and significant risks for a variety of cancers related to the interaction of environmental and genetic factors. Consistent evidence supports a role for polymorphisms of the cytochrome P450 CYP2C9 gene as a protecting factor for colorectal cancer susceptibility. It has been shown that CYP2C8 and CYP2C9 overlap in substrate specificity. Because CYP2C8 has the common functional polymorphisms rs11572080 and rs10509681 (CYP2C8*3), it could be speculated that part of the findings attributed to CYP2C9 polymorphisms may actually be related to the presence of polymorphisms in the CYP2C8 gene. Nevertheless, little attention has been paid to the role of the CYP2C8 polymorphism in colorectal cancer. We analyzed the influence of the CYP2C8*3 allele in the risk of developing colorectal cancer in genomic DNA from 153 individuals suffering colorectal cancer and from 298 age- and gender-matched control subjects. Our findings do not support any effect of the CYP2C8*3 allele (OR for carriers of functional CYP2C8 alleles = 0.50 (95% CI = 0.16-1.59; p = 0.233). The absence of a relative risk related to CYP2C8*3 did not vary depending on the tumor site. We conclude that the risk of developing colorectal cancer does not seem to be related to the commonest functional genetic variation in the CYP2C8 gene.

CYP2W1 variant alleles in Caucasians and association of the CYP2W1 G541A (Ala181Thr) polymorphism with increased colorectal cancer risk.

AIMS: To detect differences in the frequency of the known nonsynonymous CYP2W1 polymorphisms between colorectal cancer patients and healthy subjects. MATERIALS & METHODS: The study group consisted of 150 colorectal patients and 263 controls. The presence of five nonsynonymous CYP2W1 polymorphisms was analyzed by novel amplification-restriction methods. RESULTS: Two nonsynonymous SNPs causing the amino acid substitutions Val432Ile and Gln482His were monomorphic in the population study. Two nonsynonymous SNPs previously unknown in Caucasians, 1463T (rs3808348) and 173C (no rs number assigned), were detected in the population study, although these were not associated with colorectal cancer risk. Regarding the 541G/A polymorphism (rs3735684), the 541G allele (odds ratio: 2.2; 95% CI: 1.2-4.1) and the 541GG genotype (odds ratio: 2.06; 95% CI: 1.1-3.9) were associated with increased colorectal cancer risk in the population studied. Conversely, the 173C-541A-1463C haplotype (odds ratio: 0.46; 95% CI: 0.2-0.9) showed a protective odds ratio value. CONCLUSION: CYP2W1 variant alleles are common among Caucasian individuals and, of these, the CYP2W1 G541A (Ala181Thr) polymorphism is associated with increased colorectal cancer risk.

Non-invasive evaluation of the fibrosis stage in chronic hepatitis C: a comparative analysis of nine scoring methods.

OBJECTIVE: Liver biopsy is an invasive procedure and new surrogate markers to assess fibrosis are needed. We performed a comparative external evaluation of nine non-invasive scores of liver fibrosis and tried to identify other potential biochemical markers of low-stage liver fibrosis in chronic hepatitis C (CHC). MATERIAL AND METHODS: We included 429 previously untreated consecutive patients from a single centre who underwent a liver biopsy between January 1999 and April 2009. Biopsies were evaluated for the stage of fibrosis according to the METAVIR scoring method. RESULTS: None of the evaluated scores were adequate to disclose null-low fibrosis due to a lack of specificity at the proposed cut-offs and the poor sensitivity of lower cut-offs. Serum ferritin and cholesterol values were found to be independently related to the fibrosis stage and their inclusion in the best performing scores at lower cut-off values (the APRI and King's scores) improved the sensitivity for null-low fibrosis by 8% with a specificity >or= 93%. CONCLUSIONS: Approximately 30% of patients with null-low fibrosis may be accurately identified by supplementing current scores with new independent variables (serum ferritin and cholesterol), thus obviating the need for a liver biopsy.

Analysis of a non-synonymous single nucleotide polymorphism of the human diamine oxidase gene (ref. SNP ID: rs1049793) in patients with Crohn's disease.

OBJECTIVE: To analyse the possible influence of a non-synonymous single nucleotide polymorphism (SNP) of the histamine-degrading enzyme diamine oxidase (DAO) on genetic susceptibility to Crohn's disease (CD). MATERIAL AND METHODS: In this prospective, case-control study, 210 unrelated Caucasian consecutive CD patients were recruited at the Inflammatory Bowel Disease Unit of a single tertiary centre (Hospital Clínico San Carlos) in Madrid, Spain. A total of 261 healthy volunteers from the same geographic area were also recruited and matched with patients. Both cases and controls were analysed for the presence of a non-synonymous SNP (rs1049793) of DAO using amplification-restriction procedures of the genotype obtained in a blood sample. RESULTS: No significant differences were found in the distribution of carriers of the non-synonymous SNP of DAO between CD patients and controls (OR 1.2 (95% CI 0.9-1.6; p=0.3)). Nor were any differences found between carriers and non-carriers of the non-synonymous SNP in demographic characteristics, phenotypes, complications or treatment of CD. CONCLUSIONS: The study of a non-synonymous SNP (rs1049793) of DAO does not seem to be of use in assessing susceptibility to CD, either as a marker of disease activity or as a marker of clinical behaviour in patients with the disease.

"12 weeks' stopping rule" in the treatment of genotype 1 chronic hepatitis C: two prognostic categories under the same label?

OBJECTIVE: The current guidelines recommend maintenance of combined therapy for hepatitis C virus (HCV) genotype-1 chronic hepatitis when HCV-RNA is undetectable or < or = 2 log10 of baseline after 12 weeks of therapy. The aim of this study was to investigate whether the probability of obtaining sustained viral (SVR) response is similar when HCV-RNA is undetectable or is present at < or = 2 log10 level after 12 weeks of therapy. MATERIAL AND METHODS: Retrospective analysis was carried out in 208 HCV genotype-1 chronic hepatitis patients treated with pegylated interferon and ribavirin with available data on HCV viral load after 12 weeks of therapy and definite data on the results of therapy. RESULTS: Seventy-six (68.5%) out of 111 patients with undetectable HCV-RNA and 4 (11.8%) out of 34 patients with HCV-RNA < or = 2 log10 from baseline at week 12 reached SVR (odds ratio 16.29, 95% CI 5.08-67.12; p < 0.001). Sixty-three patients did not meet any of these criteria and therapy was discontinued. CONCLUSIONS: The "12-week stopping rule" includes two different categories of responders considered candidates for maintained therapy, but the probability of obtaining SVR is very low in patients with HCV-RNA that is still detectable at this time of treatment. We suggest that, in these partial responders, the prolongation of therapy should be decided on an individual basis.

Optimizing dosage and duration therapy for chronic hepatitis C <>.

UNLABELLED: Treatment response remains suboptimal for many patients with chronic hepatitis C, particularly those with genotype 1 and high levels of viremia. The efficacy of high-dose regimens of peginterferon alpha-2a and ribavirin was compared with conventional dose regimens in patients with features predicting poor treatment responses. Eligible treatment-naïve adults with genotype 1 infection, hepatitis C virus (HCV) RNA > 800,000 IU/mL and body weight > 85 kg were randomized to double-blind treatment with peginterferon alpha-2a at 180 or 270 microg/week plus ribavirin at 1,200 or 1,600 mg/day for 48 weeks (four regimens were evaluated). The primary endpoint was viral kinetics during the first 24 weeks of therapy. Among patients receiving peginterferon alpha-2a (270 microg/week) the magnitude of HCV RNA reduction was significantly greater than for patients randomized to the conventional dose of peginterferon alpha-2a (180 microg/week) for the pairwise comparison for ribavirin at 1,600 mg/day (P = 0.036) and numerically greater for the pairwise comparison for ribavirin at 1200 mg/day (P = 0.060). Patients randomized to the highest doses of peginterferon alpha-2a (270 microg/week) and ribavirin (1,600 mg/day) experienced the numerically highest rates of sustained virologic response (HCV RNA < 50 IU/mL) and the lowest relapse rate (47% and 19%, respectively). The arm with the higher doses of both drugs was less well-tolerated than the other regimens. CONCLUSION: Higher fixed doses of peginterferon alpha-2a (270 microg/week) and ribavirin (1600 mg/day) may increase sustained virologic response rates compared with lower doses of both drugs in patients with a cluster of difficult-to-treat characteristics.

Glutathione S-transferase GSTT1 and GSTM1 allozymes: beyond null alleles.

Moyer AM, Salavaggione OE, Hebbring SJ et al.: Glutathione S-transferase T1 and M1: gene sequence variation and functional genomics. Clin. Cancer Res. 13, 7207-7216 (2007). Genetic variations in the glutathione S-transferases GSTT1 and GSTM1 have been studied in many human populations, and association of these variations with environmentally-related cancers, drug-induced hepatotoxicity and even chronification of viral hepatitis has been shown. However, studies carried out to date have been limited to gene deletion, designated as null alleles, and no extensive studies on other types of genetic variations have been carried out. This study is of great importance, as it describes the occurrence and the allele frequencies for 18 SNPs in the GSTT1 gene, including four nonsynonymous SNPs, and 69 SNPs, two of which are nonsynonymous, in the GSTM1 gene. The GSTT1 SNPs leading to the amino acid substitutions Asp43Asn, Thr65Met, Thr104Pro and a single nucleotide deletion in exon 4 cause a decrease in immunoreactive protein. Interestingly, the previously described nonsynonymous GSTT1 SNPs rs2266635 (Ala21Thr), rs11550606 (Leu30Pro), rs17856199 (Phe45Cys), rs11550605 (Thr104Pro), rs2266633 (Asp141Asn) and rs2234953 (Glu173Lys) were not identified in 400 subjects, thus indicating that these variant alleles are expected to occur at extremely low frequencies. This study reinforces the need to combine SNP databases and resequencing. On combining the data reported in this study with SNP databases, the most promising target SNPs for GSTT1 association studies are those causing the amino acid changes Asp43Asn, Thr65Met, Thr104Pro and the single nucleotide deletion in exon 4. These gene variants should be analyzed in African-American and Hispanic subjects to increase the predictive capacity of genetic tests. For Caucasians and Oriental subjects, testing for null alleles seems to be sufficient.

Interaction of CYP2C8 and CYP2C9 genotypes modifies the risk for nonsteroidal anti-inflammatory drugs-related acute gastrointestinal bleeding.

OBJECTIVES: To analyze whether gene variants leading to impaired drug metabolism are related with acute gastrointestinal bleeding after nonsteroidal anti-inflammatory drugs (NSAID) use. METHODS: Common CYP2C8 and CYP2C9 polymorphisms were studied in a cross-sectional study, involving 134 NSAID-related bleeding patients and in 177 patients receiving NSAID with no adverse effects. RESULTS: Among patients receiving NSAID that are CYP2C8/9 substrates the frequencies for carriers of variant alleles versus control patients were CYP2C8*3: 0.50 vs. 0.23 [odds ratio (OR); 95% confidence interval (CI)=3.4; 1.5-7.5; P=0.002], CYP2C9*2: 0.48 vs. 0.26 (OR; 95% CI=2.7; 1.2-5.8; P=0.013) and CYP2C9*3: 0.24 vs. 0.20 (OR; 95% CI=1.3; 0.5-3.1; P=0.578). The frequencies for carriers of the CYP2C8*3+CYP2C9*2 genotype were 0.40 vs. 0.15 (OR; 95% CI=3.7; 1.6-8.9; P=0.003). These findings were not influenced by sex, age, smoking or drinking habits. Among bleeding patients receiving NSAID that are not extensively metabolized by CYP2C8/9, no differences in genotypes or allele frequencies were observed as compared with control patients. CONCLUSION: The combined presence of CYP2C8*3 and CYP2C9*2 (CYP2C8*3+CYP2C9*2 genotype), is a relevant determinant in the risk to develop gastrointestinal bleeding in patients receiving NSAID that are CYP2C8/9 substrates.

Glutathione S-transferases pi 1, alpha 1 and M3 genetic polymorphisms and the risk of hepatocellular carcinoma in humans.

INTRODUCTION: Glutathione S-transferases pi1, alpha1 and micro3 are members of an enzymatic superfamily involved in the conjugation and detoxification of carcinogens. Polymorphisms affecting the genes encoding these enzymes may modify their ability to neutralize carcinogens. Our aim was to investigate whether these polymorphisms affect the risk of developing hepatocellular carcinoma in humans. METHODS: A total of 184 white Spanish patients diagnosed with hepatocellular carcinoma and 248 healthy control subjects from the same ethnic origin were included. GSTA1*B promoter allele, GSTM3*B 3-bp-deleted allele and GSTP1 Ile105Val SNP were identified. RESULTS: No differences were found between the distribution of the studied polymorphisms, or in the allele frequencies for variant alleles in patients and controls: 0.411 and 0.371 for GSTA1, 0.116 and 0.131 for GSTM3, and 0.285 and 0.309 for GSTP1, respectively. Among patients the GSTP1 mutated allele was more frequent in those drinking more than 50 g ethanol/day (odds ratio: 2.00; 95% confidence intervals: 1.06-3.78). Age at diagnosis, gender, tobacco use and hepatitis B and C viral status did not influence these results. CONCLUSION: We conclude that the studied polymorphisms affecting GSTP1, GSTA1 and GSTM3 genes are probably not related to the risk of developing hepatocellular carcinoma in the studied population.