Association of TNF-alpha promoter polymorphisms with aspirin-induced urticaria

Pharmacogenomics of Hypersensitivity to Non-steroidal Anti-inflammatory Drugs

Non-steroidal anti-inflammatory drugs (NSAIDs) are extensively prescribed in daily clinical practice. NSAIDs are the main cause of drug hypersensitivity reactions all over the world. The inhibition of cyclooxygenase enzymes by NSAIDs can perpetuate arachidonic acid metabolism, shunting to the 5-lipoxygenase pathway and its downstream inflammatory process. Clinical phenotypes of NSAID hypersensitivity are diverse and can be classified into cross-reactive or selective responses. Efforts have been made to understand pathogenic mechanisms, in which, genetic and epigenetic backgrounds are implicated in various processes of NSAID-induced hypersensitivity reactions. Although there were some similarities among patients, several genetic polymorphisms are distinct in those exhibiting respiratory or cutaneous symptoms. Moreover, the expression levels, as well as the methylation status of genes related to immune responses were demonstrated to be involved in NSAID-induced hypersensitivity reactions. There is still a lack of data on delayed type reactions. Further studies with a larger sample size, which integrate different genetic pathways, can help overcome current limitations of gen etic/epigenetic studies, and provide valuable information on NSAID hypersensitivity reactions.

Association between TNF-α polymorphisms and the risk of upper gastrointestinal bleeding induced by aspirin in patients with coronary heart disease

OBJECTIVE

To investigate the correlation of tumor necrosis factor α (TNF-α) polymorphisms with upper gastrointestinal bleeding (UGIB) induced by enteric-coated aspirin in coronary heart disease (CHD) patients.

METHODS

In total, 154 CHD patients taking enteric-coated aspirin were enrolled in this study. Patients were divided into the UGIB group (n = 57) and non-UGIB group (n = 97) based on the presence or absence of signs of UGIB, respectively. TNF-α polymorphism (-857C > T, -863C > A, and -1031T > C) genotyping was performed using polymerase chain reaction (PCR) amplification with sequence-specific primers (PCR-SSP).

RESULTS

Patients who had the CC genotype and C allele of -1031T > C exhibited a significantly increase risk of UGIB after receiving enteric-coated aspirin (CC vs. TT: odds (OR) (95% confidence interval (CI)): 7.568 (1.527-37.49), P = 0.005; C vs. T: OR (95% CI): 1.852 (1.036-3.312), P = 0.036). Patients who had CA and CA + AA genotypes and the A allele of -863C > A also exhibited an increased risk of aspirin-induced UGIB (CA vs. CC: OR (95% CI): 2.415 (1.143-5.101), P = 0.019: CA + AA vs. CC: OR (95% CI): 2.218 (1.123-4.381), P = 0.021; A vs. C: OR (95% CI): 1.788 (1.039-3.078), P = 0.035). However, the TNF-α -857 C > T polymorphism was unrelated to the induction of UGIB by enteric-coated aspirin in CHD patients (P > 0.05). In addition, the haplotypes of CCC (-1031T > C, -863C > A, and -857C > T) markedly reduced the risk of aspirin-induced UGIB in CHD patients.

CONCLUSION

TNF-α -863A and -1031C increased the risk of UGIB induction by enteric-coated aspirin in CHD patients, whereas TNF-α -857C > T was not correlated with the UGIB risk.

Hypersensitivity reactions to nonsteroidal anti-inflammatory drugs: an update on pharmacogenetics studies

Nonsteroidal anti-inflammatory drugs are the medications most frequently involved in hypersensitivity reactions to drugs. These can be induced by specific immunological and nonimmunological mechanisms, being the latter the most frequent. The nonimmunological mechanism is related to an imbalance of inflammatory mediators, which is aggravated by the cyclooxygenase inhibition. Genetic studies suggest that multiples genes and additional mechanisms might be involved. The proposals of this review is summarize the contribution of variations in genes involved in the arachidonic acid, inflammatory and immune pathways as well as the recent genome-wide association studies findings related to cross-intolerant nonsteroidal anti-inflammatory drugs hypersensitivity reactions. In addition, using integration of different genetic studies, we propose new target genes. This will help to understand the underlying mechanism of these reactions.

An Updated Review of the Molecular Mechanisms in Drug Hypersensitivity

Drug hypersensitivity may manifest ranging from milder skin reactions (e.g., maculopapular exanthema and urticaria) to severe systemic reactions, such as anaphylaxis, drug reactions with eosinophilia and systemic symptoms (DRESS)/drug-induced hypersensitivity syndrome (DIHS), or Stevens–Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN). Current pharmacogenomic studies have made important strides in the prevention of some drug hypersensitivity through the identification of relevant genetic variants, particularly for genes encoding drug-metabolizing enzymes and human leukocyte antigens (HLAs). The associations identified by these studies are usually drug, phenotype, and ethnic specific. The drug presentation models that explain how small drug antigens might interact with HLA and T cell receptor (TCR) molecules in drug hypersensitivity include the hapten theory, the p-i concept, the altered peptide repertoire model, and the altered TCR repertoire model. The broad spectrum of clinical manifestations of drug hypersensitivity involving different drugs, as well as the various pathomechanisms involved, makes the diagnosis and management of it more challenging. This review highlights recent advances in our understanding of the predisposing factors, immune mechanisms, pathogenesis, diagnostic tools, and therapeutic approaches for drug hypersensitivity.

What we know about nonsteroidal anti-inflammatory drug hypersensitivity

Nonsteroidal anti-inf lammatory drugs (NSAIDs) are widely prescribed for the treatment of inflammatory diseases, but their use is frequently related to hypersensitivity reactions. This review outlines our current knowledge of NSAID hypersensitivity (NHS) with regard to its pathogenic, molecular, and genetic mechanisms, as well as diagnosis and treatment. The presentation of NHS varies from a local (skin and/or airways) reaction to systemic reactions, including anaphylaxis. At the molecular level, NHS reactions can be classified as cross-reactive (mediated by cyclooxygenase inhibition) or selective (specific activation of immunoglobulin E antibodies or T cells). Genetic polymorphisms and epigenetic factors have been shown to be closely associated with NHS, and may be useful as predictive markers. To diagnose NHS, inhalation or oral challenge tests are applied, with the exclusion of any cross-reactive NSAIDs. For patients diagnosed with NHS, absolute avoidance of NSAIDs/aspirin is essential, and pharmacological treatment, including biologics, is often used to control their respiratory and cutaneous symptoms. Finally, desensitization is recommended only for selected patients with NHS. However, further research is required to develop new diagnostic methods and more effective treatments against NHS.

Tanno L, Terreehorst I, Laguna JJ, Romano A, Guéant JL. Genetic variants associated with drugs-induced immediate hypersensitivity reactions: a PRISMA-compliant systematic review

Drug hypersensitivity includes allergic (AR) and nonallergic reactions (NARs) influenced by genetic predisposition. We performed a systematic review of genetic predictors of IgE-mediated AR and NAR with MEDLINE and PubMed search engine between January 1966 and December 2014. Among 3110 citations, the search selected 53 studies, 42 of which remained eligible. These eligible studies have evaluated genetic determinants of immediate reactions (IR) to beta-lactams (n = 19), NAR against aspirin (n = 12) and other nonsteroidal anti-inflammatory drugs (NSAIDs) (n = 8), and IR to biologics (n = 3). We reported two genomewide association studies and four case-control studies on candidate genes validated by replication. Genes involved in IR to beta-lactams belonged to HLA type 2 antigen processing, IgE production, atopy, and inflammation, including 4 genes validated by replications, HLA-DRA, ILR4, NOD2, and LGALS3. Genes involved in NAR to aspirin belonged to arachidonic acid pathway, membrane-spanning 4A gene family, histamine production pathway, and pro-inflammatory cytokines, while those involved in NAR to all NSAIDs belonged to arachidonic acid pathway and HLA antigen processing pathway. ALOX5 was a common predictor of studies on NAR to both aspirin and NSAIDs. Although these first conclusions could be drawn, this review highlights also the lack of reliable data and the need for replicating studies in contrasted populations, taking into account worldwide allele frequencies, gene-gene interactions, and contrasted situations of environmental exposure.

Genetic basis of hypersensitivity reactions to nonsteroidal anti-inflammatory drugs

PURPOSE OF REVIEW

NSAIDs are the main triggers of hypersensitivity reactions to drugs. However, the full genetic and molecular basis of these reactions has yet to be uncovered. In this article, we have summarized research from recent years into the effects of genetic variants on the different clinical entities induced by NSAID hypersensitivity, focusing on prostaglandin and leukotriene-related genes as well as others beyond the arachidonic acid pathway.

RECENT FINDINGS

We introduce recent contributions of high-throughput approaches including genome-wide association studies as well as available information from epigenetics and next-generation sequencing. Finally, we give our thoughts on future directions in this field, including the scope for bioinformatics and systems biology and the need for clear patient phenotyping.

SUMMARY

The full genetic and molecular basis of clinical entities induced by NSAIDs hypersensitivity has yet to be uncovered, and despite commendable efforts over recent years, no clinically proven genetic markers currently exist for these disorders. It is clear that we will continue to find more about these reactions in the coming years, concurrently with improvements in technology and experimental techniques, and a precise definition of different phenotypes.

Cardiovascular drugs and the genetic response

The emergence of personalized medicine mandates a complete understating of DNA sequence variation that modulates drug response. Initial forays have been made in the cardiac arena, yet much remains to be elucidated in the pharmacogenetics of cardiac drugs. Most progress has been made in describing DNA sequence variation related to the anticoagulant warfarin and the antiplatelet drug clopidogrel. This includes a description of DNA sequence variation that underlies pharmacokinetic and pharmacodynamic variability, the impact of such variation on predicting hard outcomes, and the ability of genotype-guided prescription to facilitate rapid titration to a therapeutic range while avoiding unnecessary high plasma levels. Nuanced prescription will require a complete inventory of DNA sequence variants that underlie drug-related side effects.

Interleukin-6 and tumor necrosis factor-alpha gene polymorphisms in chronic idiopathic urticaria

BACKGROUND

This study was performed to evaluate association of gene polymorphisms among proinflammatory cytokines and susceptibility to chronic idiopathic urticaria (CIU).

METHODS

Ninety patients with prolonged urticaria more than 6 weeks were included as case group. Single nucleotide polymorphisms (SNPs) of IL-6 (G/C -174, G/A nt565) and TNF-α (G/A -308, G/A -238) were evaluated, using polymerase chain reaction (PCR); and the results were compared to the control group.

RESULTS

G allele was significantly higher in the patients at locus of -238 of promoter of TNF-α gene (p<0.001). Frequency of following genotypes were significantly lower in patients with CIU, compared to controls: AG at -308 and GA at -238 of TNF-α gene (p<0.05 and p<0.001, respectively), CG at -174 and GG at +565 of IL-6 gene (p<0.05). Additionally, following genotypes were more common among patients with CIU: GG at -308 and -238 of TNF-α gene (p<0.05 and p<0.001, respectively), GG at -174 and GA at +565 of IL-6 gene (p<0.05).

CONCLUSIONS

Pro-inflammatory cytokine gene polymorphisms can affect susceptibility to CIU. TNF-α promoter polymorphisms as well as IL-6 gene polymorphisms are associated with CIU.

Molecular genetic mechanisms of chronic urticaria

Chronic urticaria (CU) is a common allergic skin disease that requires long-term pharmacological treatment. Some patients with severe CU suffer a poor quality of life. Although the pathogenic mechanisms of CU are not clearly understood, several groups have suggested that genetic mechanisms are involved in various CU cohorts. To further understand the molecular genetic mechanisms of CU, we summarize recent genetic data in this review. Although a few HLA alleles were suggested to be candidate markers in different ethnic groups, further replication studies that apply the recent classification are needed. Genetic polymorphisms in histamine-related genes, including FcεRI and HNMT, were suggested to be involved in mast cell activation and histamine metabolism. Several genetic polymorphisms of leukotriene-related genes, such as ALOX5, LTC4S, and the PGE2 receptor gene PTGER4, were suggested to be involved in leukotriene overproduction, a pathogenic mechanism. Further investigations using candidate gene approaches and genome-wide association studies (GWAS) will provide new insights into the molecular genetic mechanisms of CU, which will provide new marker genes for differentiation of CU phenotypes and identification of potential therapeutic targets.

Urticaria in monozygotic and dizygotic twins

Aim. To identify risk factors for urticaria, to determine the relative proportion of the susceptibility to urticaria that is due to genetic factors in an adult clinical twin sample, and to further determine whether the genetic susceptibility to urticaria overlaps with the genetic susceptibility to atopic diseases. Methods. A total of 256 complete twin pairs and 63 single twins, who were selected from sibships with self-reported asthma via a questionnaire survey of 21,162 adult twins from the Danish Twin Registry, were clinically interviewed about a history of urticaria and examined for atopic diseases. Data were analysed with Cox proportional hazards regression and variance components models. Results. A total of 151 individuals (26%) had a history of urticaria, whereas 24 (4%) had had symptoms within the past year. Female sex, HR = 2.09 (1.46–2.99), P = 0.000; hay fever, HR = 1.92 (1.36–2.72), P = 0.000; and atopic dermatitis, HR = 1.44 (1.02–2.06), P = 0.041 were significant risk factors for urticaria. After adjustment for sex and age at onset of urticaria in the index twin, the risk of urticaria was increased in MZ cotwins relative to DZ cotwins, HR = 1.42 (0.63–3.18), P = 0.394. Genetic factors explained 45% (16–74%), P = 0.005, of the variation in susceptibility to urticaria. The genetic correlation between urticaria and hay fever was 0.45 (0.01–0.89), P = 0.040. Conclusions. Susceptibility to urticaria is partly determined by genetic factors. Urticaria is more common in women, and in subjects with hay fever and atopic dermatitis, and shares genetic variance with hay fever.

Personalized cardiovascular medicine: status in 2012

Personalized medicine is the tailoring of the diagnosis, prevention, and treatment to the characteristics of each individual patient. In this review, we provide a status report on genetic variants that influence therapy with antiplatelet agents, warfarin, and statins. Resistance to clopidogrel, an antiplatelet therapy, has been shown to be present in 25% to 30% of Caucasians and an even higher percentage in Asians. Part of this resistance is because of the CYP2C19*2 allele. Administering clopidogrel on the basis of previous genetic testing remains controversial. A recent breakthrough in point-of-care genetic testing for clopidogrel might be significant, not only for genetic testing for clopidogrel, but for the whole of personalized medicine. Genetic testing for aspirin resistance is not yet recommended because of incomplete genetic data. Studies to determine the value of genetic testing before the administration of warfarin are ongoing. Testing for SLCO1B1 allele for individuals with muscle cramps who are taking statins could be very helpful but is not yet recommended as routine. Pharmacogenetics has the potential to customize therapy and move away from the current model of 1 drug fits all.

A systematic review on pharmacogenetics in cardiovascular disease: is it ready for clinical application?

Pharmacogenetics is the search for heritable genetic polymorphisms that influence responses to drug therapy. The most important application of pharmacogenetics is to guide choosing agents with the greatest potential of efficacy and smallest risk of adverse drug reactions. Many studies focusing on drug-gene interactions have been published in recent years, some of which led to adaptation of FDA recommendations, indicating that we are on the verge of the clinical application of genetic information in drug therapy. This systematic review provides a comprehensive overview of the current knowledge on pharmacogenetics of all major drug classes currently used in the treatment of cardiovascular diseases.

Personalized medicine for HLA-associated drug-hypersensitivity reactions

Multiple genetic and nongenetic factors can modify the action of a drug, resulting in varied responses to a particular drug across different individuals. Personalized medicine incorporates the comprehensive knowledge of these factors to facilitate the selection of optimal therapy, reduce adverse drug reactions, increase patient compliance and increase the efficiency of therapy. Pharmacogenomics, which integrates the knowledge of an individual’s genetic make-up for diagnostic decisions or therapeutic interventions is closely linked to personalized medicine, and is being increasingly used to prevent adverse drug reactions. There are various reports on genetic associations between particular HLA allotypes and drug hypersensitivities and the strongest associations reported thus far, are with the reverse transcriptase inhibitor, abacavir and HLA-B*5701, the gout prophylactic allopurinol and HLA-B*5801 and the antiepileptic carbamazepine and B*1502, providing a defined disease trigger and suggesting a general mechanism for these associations. Recognizing the strong HLA association, the US FDA has recommended genetic testing before starting abacavir and carbamazepine therapies. To incorporate HLA testing for other drug hypersensitivities and life-threatening reactions it is essential first to establish clear HLA associations, and second, to understand the immune-mechanism by which these drugs induce HLA-linked hypersensitivity. The latter will provide insight into the pathologic mechanisms of drug allergy allowing rational immunotherapy for these life-threatening reactions and the development of alternative drug therapies for hypersensitive patients.