Objective. To determine associations of methotrexate (MTX) efficacy and toxicity with single-nucleotide polymorphisms (SNPs) in genes coding for folate pathway enzymes in patients with early rheumatoid arthritis (RA).Methods. Patients (n ؍ 205) with active RA received MTX at an initial dosage of 7.5 mg/week, which was increased to 15 mg/week and combined with folic acid (1 mg/day) after 4 weeks. If the Disease Activity Score in 44 joints (DAS44) was >2.4 at 3 months, MTX was increased to 25 mg/week. MTX efficacy was evaluated at 3 and 6 months and compared for genotypes in 3 analyses: patients with and without good response (DAS44 <2.4), patients with and without good improvement (⌬DAS44 >1.2), and patients with and without moderate improvement (⌬DAS44 >0.6). The association between MTX-related adverse drug events (ADEs) and genotype was evaluated by comparing genotypes between patients with and without ADEs, specifically pneumonitis, gastrointestinal ADEs, skin and mucosal ADEs, and elevated liver enzyme levels. The following SNPs were analyzed: methylenetetrahydrofolate reductase (MTHFR) 677C>T, MTHFR 1298A>C, dihydrofolate reductase (DHFR) ؊473G>A, DHFR 35289G>A, and reduced folate carrier 80G>A. In case of significant differences, odds ratios (ORs) were calculated.Results. At 6 months, MTHFR 1298AA was associated with good improvement relative to 1298C (OR 2.3, 95% confidence interval [95% CI] 1.18-4.41), which increased with increased copies of the MTHFR 677CC haplotype. In contrast, MTHFR 1298C allele carriers developed more ADEs (OR 2.5, 95% CI 1.32-4.72).Conclusion. Patients with MTHFR 1298AA and MTHFR 677CC showed greater clinical improvement with MTX, whereas only the MTHFR 1298C allele was associated with toxicity. In the future, MTHFR genotypes may help determine which patients will benefit most from MTX treatment.Methotrexate (MTX) is the most widely used disease-modifying antirheumatic drug (DMARD) for the treatment of rheumatoid arthritis (RA), and has proven to reduce disease activity and delay or stabilize the development of bone erosions (1,2). However, only ϳ50% of the patients experience good clinical response, and 30% discontinue therapy due to side effects (3,4).
BackgroundLead is an environmental pollutant that causes acute and chronic toxicity. Surveys have related mean blood lead concentrations to exogenous sources, including industrial activity, use of lead-based paints, or traffic density. However, there has been little investigation of individual differences in lead absorption, distribution, or toxicity, or of genetic causes of such variation.ObjectivesWe assessed the genetic contribution to variation in blood lead concentration in adults and conducted a preliminary search for genes producing such variation.MethodsErythrocyte lead concentration was measured by inductively coupled plasma mass spectrometry in venous blood samples from 2,926 Australian adult male and female twins. Mean lead concentrations were compared by place of residence, social class and education, and by the subjects’ age, sex, alcohol intake, smoking habits, iron status, and HFE genotype.ResultsAfter adjustment for these covariates, there was strong evidence of genetic effects but not for shared environmental effects persisting into adult life. Linkage analysis showed suggestive evidence (logarithm of odds = 2.63, genome-wide p = 0.170) for a quantitative trait locus affecting blood lead values on chromosome 3 with the linkage peak close to SLC4A7, a gene whose product affects lead transport.ConclusionsWe conclude that genetic variation plays a significant role in determining lead absorption, lead distribution within the body, or both.
The bodily decline that occurs with advancing age strongly impacts on the prospects for future health and life expectancy. Despite the profound role of age in disease etiology, knowledge about the molecular mechanisms driving the process of aging in humans is limited. Here, we used an integrative network-based approach for combining multiple large-scale expression studies in blood (2539 individuals) with protein–protein Interaction (PPI) data for the detection of consistently coexpressed PPI modules that may reflect key processes that change throughout the course of normative aging. Module detection followed by a meta-analysis on chronological age identified fifteen consistently coexpressed PPI modules associated with chronological age, including a highly significant module (P = 3.5 × 10−38) enriched for ‘T-cell activation’ marking age-associated shifts in lymphocyte blood cell counts (R2 = 0.603; P = 1.9 × 10−10). Adjusting the analysis in the compendium for the ‘T-cell activation’ module showed five consistently coexpressed PPI modules that robustly associated with chronological age and included modules enriched for ‘Translational elongation’, ‘Cytolysis’ and ‘DNA metabolic process’. In an independent study of 3535 individuals, four of five modules consistently associated with chronological age, underpinning the robustness of the approach. We found three of five modules to be significantly enriched with aging-related genes, as defined by the GenAge database, and association with prospective survival at high ages for one of the modules including ASF1A. The hereby-detected age-associated and consistently coexpressed PPI modules therefore may provide a molecular basis for future research into mechanisms underlying human aging.
Sézary syndrome (Sz) is a malignancy of skin-homing CD4(+) memory T cells that is clinically characterized by erythroderma, lymphadenopathy, and blood involvement. Distinction of Sz from erythroderma secondary to inflammatory skin diseases (erythrodermic inflammatory dermatosis [EID]) is often challenging. Recent studies identified recurrent mutations in epigenetic enzymes involved in DNA modification in Sz. Here we defined the DNA methylomes of purified CD4(+) T cells from patients with Sz, EID, and healthy control subjects. Sz showed extensive global DNA methylation alterations, with 7.8% of 473,921 interrogated autosomal CpG sites showing hypomethylation and 3.2% hypermethylation. Promoter CpG islands were markedly enriched for hypermethylation. The 126 genes with recurrent promoter hypermethylation in Sz included multiple candidate tumor suppressors that showed transcriptional repression, implicating aberrant methylation in the pathogenesis of Sz. Validation in an independent sample set showed promoter hypermethylation of CMTM2, C2orf40, G0S2, HSPB6, PROM1, and PAM in 94-100% of Sz samples but not in EID samples. Notably, promoter hypermethylation of a single gene, the chemokine-like factor CMTM2, was sufficient to accurately distinguish Sz from EID in all cases. This study shows that Sz is characterized by widespread yet distinct DNA methylation alterations, which can be used clinically as epigenetic diagnostic markers.
Objective On December 8–9, 2014, the Pennington Biomedical Research Center convened a scientific symposium to review the state-of-the-science and future directions for the study of developmental programming of obesity and chronic disease. The objectives of the symposium were to discuss: (i) past and current scientific advances in animal models, population-based cohort studies and human clinical trials, (ii) the state-of-the-science of epigenetic-based research, and (iii) considerations for future studies. Results The overarching goal was to provide a comprehensive assessment of the state of the scientific field, to identify research gaps and opportunities for future research in order to identify and understand the mechanisms contributing to the developmental programming of health and disease. Conclusions Identifying the mechanisms which cause or contribute to developmental programming of future generations will be invaluable to the scientific and medical community. The ability to intervene during critical periods of prenatal and early postnatal life to promote lifelong health is the ultimate goal. Considerations for future research including the use of animal models, the study design in human cohorts with considerations about the timing of the intrauterine exposure and the resulting tissue specific epigenetic signature were extensively discussed and are presented in this meeting summary.
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