Biomedical subjects

Ann K Daly

Publications and source records attributed to Ann K Daly.

18 recordsLinked to original sources

PubMed2026

HLA and non-HLA genetic analyses reveal suggestive variants associated with statin-induced liver injury.

BACKGROUND: Statins are widely prescribed for cardiovascular risk reduction and are generally well tolerated. However, they can cause drug-induced liver injury (DILI), and the genetic factors contributing to statin-DILI remain poorly understood. METHODS: HLA association and genome-wide association (GWAS) studies were conducted to identify genetic variants associated with statin-DILI. High-confidence cases (n=71) were identified from the Drug-Induced Liver Injury Network (DILIN) and compared with statin-exposed controls without liver injury (n=551) from the Indiana Biobank. Association testing was performed across ancestries and within ancestry, adjusting for age, sex, and three principal components of genotypes. Top variants were further evaluated in non-statin DILI cases and unexposed controls. In addition, we investigated the frequency of candidate variants among a comprehensive list of pharmacogenetic variants related to statins. RESULTS: HLA-DQA1*03:01 was significantly associated with increased risk of statin-DILI (OR=3.49, 95% CI 2.21-5.51, p-value=1.27×10-7), with enrichment observed across multiple ancestry groups, particularly non-Hispanic Black and Hispanic individuals. From the GWAS, three loci showed suggestive associations (p-value <5×10-06) with statin-DILI, including rs35197737 in RGS1 (OR=5.03, 95% CI 1.11-3.66, p=1.14×10-7), rs75629598 in FRMD4A (OR=4.4, 95% CI=2.33-8.12, p=3.97×10-6), and rs7658630 in the intergenic region on chromosome 4 (OR=4.86, 95% CI 2.66-8.85, p=2.68×10-7). No pharmacogenetic variants revealed statistical significance. CONCLUSION: We identified HLA and non-HLA genetic variants associated with statin DILI. Future studies with larger sample sizes should confirm these observations.

Humans↗

PubMed2025

Germline Variants Influence Chronic Liver Disease Progression through Distinct Pathways.

Cirrhosis and hepatocellular carcinoma (HCC) are long-term complications of chronic liver disease (CLD). In this large multi-ancestry genome-wide association study of all-cause cirrhosis (35,481 cases, 2.36M controls) and HCC (6,680 cases, 1.76M controls), we identified 27 loci associated with cirrhosis (10 novel) and 11 with HCC (three novel). Three novel cirrhosis loci were replicated in independent cohorts (e.g. FGF21, RPTOR, and IFNL3/4). Fifteen cirrhosis loci exhibited differential effects on cirrhosis risk via underlying etiologies, and six HCC loci influenced HCC risk indirectly via cirrhosis. In a gene-burden analysis of rare variants from whole-genome sequencing data in the VA Million Veteran Program (n=102,677), we identified GSTA5 as a novel cirrhosis-associated gene, while APOB and ATP9B were associated with and replicated for HCC. A high genetic risk score for cirrhosis was associated with a nearly doubled risk of CLD progressing to cirrhosis (HR=1.94, P=2×10-68) and of cirrhosis progressing to HCC (HR=1.65, P=7×10-08). Finally, among individuals with chronic hepatitis C who underwent antiviral therapy, cirrhosis risk was modified by variants in PNPLA3, IFNL3/4, and CD81 following pegylated interferon-α therapy, and by APOE lead variant following direct-acting antiviral therapy. These findings provide new insights into the complex genetic architecture of CLD progression with potential clinical and therapeutic implications.

Journal Article↗

PubMed2003

Impact of cytochrome p450 3A5 genetic polymorphism on tacrolimus doses and concentration-to-dose ratio in renal transplant recipients.

BACKGROUND: Tacrolimus pharmacokinetic characteristics vary greatly among individuals. Tacrolimus is a substrate of cytochrome p450 (CYP), of subfamily CYP3A. CYP3A activity is the sum of the activities of the family of CYP3A genes, including CYP3A5. Subjects with the CYP3A5*1/*1 genotype express large amounts of CYP3A5. Heterozygotes (genotype CYP3A5*1/*3) also express the enzyme. We postulated that CYP3A5 polymorphism is associated with tacrolimus pharmacokinetic variations. METHODS: CYP3A5 genotype was evaluated in 80 renal transplant recipients and correlated with the daily tacrolimus dose and concentration-to-dose ratio. RESULTS: The frequency of the homozygous CYP3A5*1 genotype (CYP3A5*1/*1) was 5%, and 11% of subjects were heterozygous (CYP3A5*1/*3). The mean doses required to obtain the targeted concentration-to-dose ratio were significantly lower in patients with the CYP3A5*1/*1 genotype. CONCLUSIONS: Determination of CYP3A5 genotype is predictive of the dose of tacrolimus in renal transplant recipients and may help to determine the initial daily dose needed by individual patients for adequate immunosuppression without excess nephrotoxicity.

Adult↗

PubMed2003

Development of analytical technology in pharmacogenetic research.

Methods used to determine phenotype and genotype for pharmacogenetic polymorphisms are discussed. Phenotyping is mainly applicable to polymorphisms affecting drug disposition rather than drug response and can involve either direct measurement of enzyme activity or administration of a probe drug followed by measurement of drug and/or metabolite levels. Genotyping is now more widely used than phenotyping and can be used to determine genotype for polymorphisms affecting either drug disposition (for example those in the cytochromes P450 or N-acetyltransferases) or drug response (for example those in drug receptors). Most genotyping for known polymorphisms involves use of the polymerase chain reaction and the wide variety of methods based on this technique that are now used for routine genotyping are discussed in detail. In addition, a range of methods that can be used to detect novel polymorphisms, thereby further increasing understanding of interindividual variability in drug disposition and response, is described.

Animals↗

PubMed2003

Do multiple cytochrome P450 isoforms contribute to parathion metabolism in man?

Phosphorothioate compounds are widely used in agriculture and public health for the control of unwanted pests. The phosphorothioate parathion was metabolised to the toxic metabolite paraoxon (0.038-0.683 nmol/min per mg protein) and p-nitrophenol (0.023-2.10 nmol/min per mg protein) by human liver microsomes ( n=27) in an NADPH-dependent reaction. There was a significant correlation ( P<0.02) between nifedipine oxidation and paraoxon formation from parathion (200 micro M) by human liver microsomes and with cytochrome P450 (CYP) 3A4/5 expression ( P<0.05), although not with midazolam 1'-hydroxylation or testosterone 6beta-hydroxylation. Paclitaxel 6'-hydroxylation and CYP2C8 expression correlated with paraoxon formation ( P<0.01), indicating CYP2C8 involvement. Of nine recombinant P450 isoforms, CYPs 3A4, 3A5, 1A2 and 2D6 activated parathion to paraoxon at the highest rates (6.5, 8.5, 5.7 and 6.2 pmol/pmol P450 per h) with K(m) values of 12.6, 2.7, 1.5 and 9.2 micro M, respectively. Similar K(m) values were seen with the human liver microsomes. These data indicate that CYP3A4/5 and CYP2C8, which constitute up to 40% of human liver P450s, are the most significant participants in the metabolism of parathion. However, several other isoforms could play an important role when CYP3A and CYP2C8 are poorly expressed due to environmental factors or the presence of a genetic polymorphism.

Animals↗

PubMed2003

Polymorphism in CYP2C8 is associated with reduced plasma concentrations of repaglinide.

OBJECTIVE: Our objective was to investigate the effects of genetic polymorphisms of cytochrome P450 (CYP) 2C8 on the pharmacokinetics and pharmacodynamics of the meglitinide analog antidiabetic drug repaglinide. METHODS: We genotyped 28 healthy volunteers who had participated in our pharmacokinetic studies on repaglinide for variant alleles of the CYP2C8 gene. Each subject ingested a 0.25-mg dose of repaglinide, and plasma drug and blood glucose concentrations were monitored for 7 hours after dosing. RESULTS: There were 19 subjects (68%) with the CYP2C8*1/*1 genotype (wild type), 6 subjects (21%) with the CYP2C8*1/*3 genotype, and 3 subjects (11%) with the CYP2C8*1/*4 genotype. In the 3 genotypic groups, the mean +/- SD area under the plasma repaglinide concentration-time curve from time 0 to infinity [AUC(0- infinity )] was 5.8 +/- 2.5 ng. h/mL for CYP2C8*1/*1, 3.6 +/- 0.9 ng. h/mL for CYP2C8*1/*3, and 5.1 +/- 3.6 ng. h/mL for CYP2C8*1/*4. The mean AUC(0- infinity ) of repaglinide was 45% (P <.005) lower and the peak concentration in plasma was 39% lower (P <.05) in subjects with the CYP2C8*1/*3 genotype compared with those with the CYP2C8*1/*1 genotype. No statistically significant differences were found in the blood glucose response to repaglinide between the genotypes. CONCLUSIONS: Unexpectedly, the CYP2C8*3 variant allele was associated with reduced plasma concentrations of repaglinide. The effects of CYP2C8 polymorphisms on the pharmacokinetics of CYP2C8 substrates warrant further study.

Adult↗

PubMed2003

CYP3A5 phenotype-genotype correlations in a British population.

AIMS: To develop a polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP)-based assay to genotype for hepatic CYP3A5 expression and to use this assay to study a British population. METHODS: CYP3A5-specific primers were designed with one including a base-pair mismatch to create a RsaI site in samples positive for G6986 (CYP3A5*3 allele) [correction]. Following PCR and RsaI digestion, different band patterns on electrophoresis were predicted for individuals positive for CYP3A5 (CYP3A5*1 allele) compared with those who do not express the gene (CYP3A5*3 homozygotes). The assay was validated by DNA sequencing. DNA samples from a human liver bank consisting of 22 livers whose CYP3A5 expression had been determined by immunoblotting and a group of random individuals (n = 100) from the North-east of England were genotyped by the new assay. RESULTS: In the liver bank, five out of 22 samples expressed CYP3A5 at significant levels (>20 pmol mg-1 protein) and were found to have the genotype CYP3A5*1/CYP3A5*3 by the PCR-RFLP assay. All other liver DNA samples were CYP3A5*3 homozygotes. In the group of 100 random individuals, 13 had the genotype CYP3A5*1/CYP3A5*3 and all others were CYP3A5*3 homozygotes, predicting that 13% (95% confidence interval (CI) 6%, 20%) would show significant hepatic CYP3A5 expression. The frequency for the CYP3A5*1 allele was 0.065 (95% CI 0.032, 0.097). CONCLUSIONS: We have developed a simple assay for the detection of the CYP3A5*1/CYP3A5*3 alleles and shown that in a British population their frequency is similar to that reported previously. We have also shown a good correlation between hepatic CYP3A5 expression and genotype for a British Caucasian liver bank.

Adult↗

PubMed2003

Genetic and epigenetic factors in autoimmune reactions toward cytochrome P4502E1 in alcoholic liver disease.

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.

Abatacept↗

PubMed2003

Pharmacogenetics of oral anticoagulants.

There is wide interindividual variation in oral anticoagulant dose requirement, which is partly genetically determined. Several cytochrome P450s contribute to oxidative metabolism of oral anticoagulants. The most important of these is CYP2C9, which hydroxylates the S-enantiomers of warfarin, acenocoumarol and phenprocoumon with high catalytic activity. In at least eight separate clinical studies, possession of the CYP2C9*2 or CYP2C9*3 variant alleles, which result in decreased enzyme activity, has been associated with a significant decrease in a mean warfarin dose requirement. Several studies also suggest that possession of a CYP2C9 variant allele is associated with an increased risk of adverse events, such as bleeding. Possession of the CYP2C9*3 variant also appears to be associated with a low acenocoumarol dose requirement. Other genetic factors, such as polymorphisms in the cytochromes P450 that metabolize the R-enantiomers of warfarin and acenocoumarol, may also be relevant to anticoagulant dose. The molecular basis of anticoagulant resistance where a higher than normal dose of anticoagulant is required remains unclear, but could be due to unusually high CYP2C9 activity (pharmacokinetic resistance) or to an abnormality in the target enzyme vitamin K epoxide reductase (pharmacodynamic resistance).

Administration, Oral↗

PubMed2003

Altered tropomyosin expression in essential hypertension.

Abnormal erythrocyte sodium-lithium countertransport is common in a subgroup of patients with essential hypertension and a strong family history of hypertension and cardiovascular disease. We have previously shown that the abnormality in sodium-lithium countertransport is associated with tropomyosin, a cytoskeletal protein required to stabilize actin filament formation. Leukocyte trafficking events, which depend on cytoskeletal reorganization, are also altered in patients with essential hypertension with abnormal sodium-lithium countertransport. The aim of this study was to determine whether there is an abnormality in isoforms of tropomyosin that are common to erythrocytes and leukocytes. Analysis of reticulocyte RNA by reverse transcription (RT) and polymerase chain reaction (PCR) showed expression of TPMN and TPM5b isoforms of tropomyosin. No other isoforms were expressed. These isoforms were also detected in RNA from leukocytes. In patients with essential hypertension with abnormal erythrocyte sodium-lithium countertransport compared with normal control subjects, there was a higher TPMN/TPM5b ratio of protein in erythrocytes (median 3.8 [range 1.8 to 6.6] versus 2.9 [1.9 to 4.0], P<0.001) and of RNA in leukocytes (3.7 [1.7 to 8.2] versus 2.6 [1.2 to 4.3], P<0.01). Furthermore, the protein ratio of TPMN/TPM5b in erythrocytes showed significant correlation with the V(max)/K(m) ratio of sodium-lithium countertransport across the patient groups (r=-0.42; P<0.01). Therefore, altered tropomyosin expression may be the underlying abnormality associated with blood cell membrane changes in essential hypertension and implicates the cytoskeleton in the pathogenesis of the disease in a major subgroup of patients.

Aged↗

PubMed2003

Candidate gene case-control studies.

Two main approaches to the identification of genes are involved in polygenic diseases. Use of family studies has generally been the preferred approach up until recently, but this is only feasible if the genetic component of the disease is relatively strong and DNA samples are available from other family members. Population case-control studies are useful both as an alternative and an adjunct to family studies. These can involve either whole genome scanning or candidate gene approaches. While whole genome scanning is likely to be widely used in the future once more information on genome-wide single nucleotide polymorphism distributions is available, at present, candidate gene studies are more feasible. When performing candidate gene case-control studies factors such as study design, methods for recruitment of case and controls, selection of candidate genes, functional significance of polymorphisms chosen for study and statistical analysis require close attention to ensure that only genuine associations are detected. Some examples of the successful use of candidate gene case-control studies are discussed and, to illustrate some potential problems in the design and interpretation of association studies, some specific examples of association studies on cancer are considered.

Case-Control Studies↗

PubMed2002

CYP2C8 polymorphisms in Caucasians and their relationship with paclitaxel 6alpha-hydroxylase activity in human liver microsomes.

Published cDNA sequences suggest the existence of non-synonymous single nucleotide polymorphisms in the cytochrome P450 CYP2C8. To determine whether these polymorphisms could be confirmed in a Caucasian population and to investigate whether additional polymorphisms occur in the coding and upstream regions of this gene, we screened for previously described and for novel polymorphisms using PCR-RFLP and SSCP analysis. We confirmed the existence of two of the previously detected polymorphisms which give rise to the amino acid substitutions I264M and K399R, respectively, but failed to detect three others in our population. We also confirmed that a recently identified polymorphism (R139K) is linked to K399R (CYP2C8*3) in our study population. The allele frequencies for the I264M (CYP2C8*4 allele) and the CYP2C8*3 allele were 0.075 and 0.15, respectively. Three novel polymorphisms (T-370G, C-271A and T1196C/L390S) were also detected with the upstream polymorphisms showing allele frequencies of 0.061 and 0.196, respectively, but the L390S polymorphism detected only in a single subject. An additional single subject was heterozygous for a polymorphism recently described in African-Americans (A805T; CYP2C8*2 allele). The functional significance of the two upstream polymorphisms and the CYP2C8*3 and CYP2C8*4 alleles was investigated in human liver microsomes. Samples heterozygous for CYP2C8*3 showed significantly lower paclitaxel 6alpha-hydroxylase activity compared with wild-type samples. Median activity associated with CYP2C8*4 also appeared lower than the wild-type but the difference was not significant. There was no evidence that either upstream polymorphism gave rise to altered CYP2C8 expression.

Amino Acid Sequence↗

PubMed2002

Cytochrome P450 CYP1B1 and catechol O-methyltransferase (COMT) genetic polymorphisms and breast cancer susceptibility in a Turkish population.

Epidemiological studies indicate that most risk factors for breast cancer are related to reproductive and hormonal factors. Estrogen has been proposed to trigger breast cancer development via an initiating mechanism involving its metabolite, catechol estrogen (CE). Because of the important role of cytochrome P450 1B1 ( CYP1B1) and catechol O-methyltransferase ( COMT) in mammary estrogen and carcinogen metabolism, we examined the CYP1B1 and COMT genes to determine whether genetic variations could account for inter-individual differences in breast cancer. In this case-control study, we determined CYP1B1 and COMT genotypes in 84 breast cancer patients and 103 healthy unrelated women controls from a Turkish population. In the case of CYP1B1, we genotyped CYP1B1*3 (L432 V) allele. We found that carriers of the CYP1B1*3 allele were more frequent among breast cancer patients with adjusted odds ratio (OR) for age, age at menarche, age at first full-term pregnancy, body mass index (BMI) and smoking status of 2.32 (95% confidence interval 1.26-4.25) associated with the allele. However, this allele appeared to be a significant factor for susceptibility only in patients with a BMI greater than 24 kg/m(2). Menopausal status did not appear to affect susceptibility. In the case of COMT, there was no significant difference in susceptibility for breast cancer development between patients with low activity COMT-L (V158 M) allele and high activity COMT-H allele, and susceptibility was not affected by menopausal status, BMI or CYP1B1 genotype. We conclude that the CYP1B1* 3 allele appears to be a factor for susceptibility to breast cancer in Turkish women especially those with a BMI greater than 24 kg/m(2).

Adult↗

PubMed2002

Pooled analysis and meta-analysis of glutathione S-transferase M1 and bladder cancer: a HuGE review.

Smoking is a known risk factor for bladder cancer. The product of the GSTM1 gene, glutathione S-transferase M1 (GSTM1), is involved in the detoxification of polycyclic aromatic hydrocarbons found in tobacco smoke; a homozygous deletion of this gene in approximately 50% of Caucasians and Asians results in a lack of GSTM1 enzyme activity. Most studies examining the relation between bladder cancer and GSTM1 have reported an increased risk associated with a lack of GSTM1 activity. The authors performed meta- and pooled analyses of published and unpublished, case-control, genotype-based studies that examined this association (17 studies, 2,149 cases, 3,646 controls) and excluded studies conducted in populations with a high prevalence of exposure to known bladder cancer risk factors other than tobacco smoke. Using random effects models in the meta-analysis, the authors obtained a summary odds ratio of 1.44 (95% confidence interval (CI): 1.23, 1.68) for GSTM1 null status with all studies included. Results from studies with at least 100 cases and 100 controls produced a summary odds ratio of 1.42 (95% CI: 1.26, 1.60). Pooled analyses using original data sets from 10 studies (1,496 cases and 1,444 controls) and adjusting for age, sex, and race produced similar results. There was no evidence of multiplicative interaction between the GSTM1 null genotype and ever smoking in relation to bladder cancer, although there was a suggestion of additive interaction (additive interaction = 0.45, 95% CI: -0.03, 0.93). These results indicate that, among populations studied to date, GSTM1 null status is associated with a modest increase in the risk of bladder cancer.

Benzo(a)pyrene↗

PubMed2002

Pharmacogenetics of tardive dyskinesia: combined analysis of 780 patients supports association with dopamine D3 receptor gene Ser9Gly polymorphism.

Variability among individuals in their therapeutic response to psychotropic drugs and in susceptibility to adverse effects is considerable. Pharmacogenetics addresses the contribution of genetic factors to this variability. An important focus of interest in pharmacogenetics has been on candidate genes that play a role in susceptibility to the antipsychotic drug-induced adverse effect, tardive dyskinesia (TD). Four published studies have reported an association between a serine (ser) to glycine (gly) polymorphism in exon 1 of the dopamine D3 receptor gene (DRD3) and TD; three failed to replicate this finding and one found an insignificant trend. We examined the association in a pooled sample of 780 patients (317 with TD and 463 without TD) drawn from 6 research centers, who were divided into 8 groups based on their population origin. The analysis employed stepwise logistic regression so as to allow confounding effects of group, age, and gender to be taken into account. TD was significantly associated with DRD3 gly allele carrier status (x(2)=4.46, df 1, p =.04) and with DRD3 genotype (x(2)=6.62, df 2, p =.04) over and above the effect of group. Similar positive effects were observed when controlling for age and gender (x(2)=5.02, df 1, p =.02 for gly allele carrier status; x(2) = 7.51, df 2, p =.002 for genotype). Examining abnormal involuntary movement scores as a continuous variable, we found that patients homozygous for the gly allele had significantly higher scores than ser-gly heterozygotes (p =.006) or ser-ser homozygotes (p <.0001). We also performed a meta-analysis that included, besides the groups in the combined analysis, three other published studies on DRD3 and TD. The Mantel-Haenszel pooled odds ratio for DRD3 gly allele carrier status increasing susceptibility to TD was 1.33 (95% CI 1.04-1.70, p =.02); the cumulative pooled estimate showed an odds ratio of 1.52 (95% CI 1.08-1.68, p <.0001). These findings support a small but significant contribution of the DRD3 ser9gly polymorphism to TD susceptibility that is demonstrable over and above population effects and the effect of age and gender on the phenotype.

Adult↗

PubMed2002

CYP2C9 polymorphism and warfarin dose requirements.

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Alleles↗

PubMed2002

Valine-alanine manganese superoxide dismutase polymorphism is not associated with alcohol-induced oxidative stress or liver fibrosis.

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.

Alanine↗

PubMed2002

Polymorphisms in immunoregulatory genes: towards individualized immunosuppressive therapy?

In organ transplantation, successful immunosuppression requires that both rejection and infection episodes be minimized. Unfortunately it is currently impossible to predict individual dose requirement for immunosuppressive drugs, but a number of studies of various immune response genes are now being performed with a view to identifying genotypes associated with rejection and/or infection. The key role of cytokines in the immune response and other processes, including fibrosis, has concentrated most of this attention on polymorphisms in cytokine genes. Data on polymorphisms in genes encoding tumor necrosis factor-alpha, transforming growth factor-beta, interferon-gamma and interleukin (IL)-1, 4, 6 and 10 together with the IL-4 receptor have been analyzed but so far there is currently no indication of any consistently positive associations between graft rejection and any of these polymorphisms. Studies of other immunomodulatory genes including the CTLA4 gene and the chemokine receptor CCR-5 have proved more positive though the data, so far, are only preliminary. In conclusion, additional large series studies of these and other cytokine genes, as well as other immunoregulatory gene polymorphisms of proven functional significance are needed to achieve major progress in this area.

Cytokines↗