Genetic factors affecting antimicrobial-induced liver injury

PhD ThesisFlucloxacillin and co-amoxiclav are both associated with drug-induced liver injury (DILI). HLA genotype is an important predictor of DILI susceptibility but it is likely that non-HLA risk factors also contribute. This study aimed to characterise non-HLA risk factors in larger cohorts (155 flucloxacillin and 165 co-amoxiclav adjudicated cases) than previously. Drug causality of the cases was assessed using the RUCAM method which showed 88.1% of the cases were either highly probable or probable but 11.9% of them indicated a possible causality for the drug. Variants showing associations in previous candidate gene, genome-wide association and exome sequencing studies were genotyped to extend these findings. A SNP (rs2476601) in PTPN22, which encodes a protein involved in T-cell-receptor signalling had already been shown to be a risk factor for co-amoxiclav DILI. This was confirmed by genotyping co-amoxiclav DILI cases (n=99) (OR=2.74, 95% CI=1.58–4.77; P=4.1x10-4). There was also a significant effect for flucloxacillin DILI (OR=1.9, 95% CI=1.1–3.1; P=0.02). Exome sequencing performed previously on 66 UK co-amoxiclav DILI cases reported significant associations for several variants, including rs117511121 in IL12RB1 and rs145855109 in TPH1. Additional cases (n=99) were genotyped for rs117511121, confirming the association (OR 6.5, 95% CI=1.5-27.8; P=0.012). No association with IL12RB1 genotype was seen for flucloxacillin DILI. Functional analysis of IL12RB1 using reporter gene constructs revealed significantly lower luciferase activity for the variant constructs. The TPH1 variant was confirmed to be associated with co-amoxiclav DILI (n=99) (OR=14.73, 95% CI=2.94–73.92; P=0.013). Polymorphisms in the following genes showed no significant association with DILI due to either drug: FMO5, GPX1, GSTM1, GSTT1, HFE, KCNJ1, SHMT1, SLCO1B1, SOD2, ST6GAL1 and UGT1A1. The findings for PTPN22 and IL12RB1 confirm the relevance of T cell responses to co-amoxiclav DILI. Odds ratios of 17 for DILI risk can be calculated for individuals with the at risk HLA alleles (A*02:01 and DRB1*15:01) and the PTPN22 and IL12RB1 variants, assuming an additive model. PTPN22 is also relevant to flucloxacillin DILI but, though biologically plausible as a risk factor, appears minor compared with HLA-B*57:01

Associations Between Telomere Attrition, Genetic Variants in Telomere Maintenance Genes, and Non-Small Cell Lung Cancer Risk in the Jammu and Kashmir Population of North India

BACKGROUND: Telomeres are repetitive DNA sequences located at the ends of chromosomes, playing a vital role in maintaining chromosomal integrity and stability. Dysregulation of telomeres has been implicated in the development of various cancers, including non-small cell lung cancer (NSCLC), which is the most common type of lung cancer. Genetic variations within telomere maintenance genes may influence the risk of developing NSCLC. The present study aimed to evaluate the genetic associations of select variants within telomere maintenance genes in a population from Jammu and Kashmir, North India, and to investigate the relationship between telomere length and NSCLC risk. METHODS: We employed the cost-effective and high-throughput MassARRAY MALDI-TOF platform to assess the genetic associations of select variants within telomere maintenance genes in a population from Jammu and Kashmir, North India. Additionally, we used TaqMan genotyping to validate our results. Furthermore, we investigated telomere length variation and its relation to NSCLC risk in the same population using dual-labeled fluorescence-based qPCR. RESULTS: Our findings revealed significant associations of TERT rs10069690 and POT1 rs10228682 with NSCLC risk (adjusted p-values = 0.019 and 0.002, respectively), while TERF2 rs251796 and rs2975843 showed no significant associations. The TaqMan genotyping validation further substantiated the associations of TERT rs10069690 and rs2242652 with NSCLC risk (adjusted p-values = 0.02 and 0.003, respectively). Our results also demonstrated significantly shorter telomere lengths in NSCLC patients compared to controls (p = 0.0004). CONCLUSION: This study highlights the crucial interplay between genetic variation in telomere maintenance genes, telomere attrition, and NSCLC risk in the Jammu and Kashmir population of North India. Our findings suggest that TERT and POT1 gene variants, along with telomere length, may serve as potential biomarkers and therapeutic targets for NSCLC in this population. Further research is warranted to elucidate the underlying mechanisms and to explore the potential clinical applications of these findings

Long non-coding RNAs modulate tumor microenvironment to promote metastasis: novel avenue for therapeutic intervention

Cancer is a devastating disease and the primary cause of morbidity and mortality worldwide, with cancer metastasis responsible for 90% of cancer-related deaths. Cancer metastasis is a multistep process characterized by spreading of cancer cells from the primary tumor and acquiring molecular and phenotypic changes that enable them to expand and colonize in distant organs. Despite recent advancements, the underlying molecular mechanism(s) of cancer metastasis is limited and requires further exploration. In addition to genetic alterations, epigenetic changes have been demonstrated to play an important role in the development of cancer metastasis. Long non-coding RNAs (lncRNAs) are considered one of the most critical epigenetic regulators. By regulating signaling pathways and acting as decoys, guides, and scaffolds, they modulate key molecules in every step of cancer metastasis such as dissemination of carcinoma cells, intravascular transit, and metastatic colonization. Gaining a good knowledge of the detailed molecular basis underlying lncRNAs regulating cancer metastasis may provide previously unknown therapeutic and diagnostic lncRNAs for patients with metastatic disease. In this review, we concentrate on the molecular mechanisms underlying lncRNAs in the regulation of cancer metastasis, the cross-talk with metabolic reprogramming, modulating cancer cell anoikis resistance, influencing metastatic microenvironment, and the interaction with pre-metastatic niche formation. In addition, we also discuss the clinical utility and therapeutic potential of lncRNAs for cancer treatment. Finally, we also represent areas for future research in this rapidly developing field

Drug-Induced Liver Injury due to Flucloxacillin:Relevance of Multiple Human Leukocyte Antigen Alleles

© 2019 The Authors Clinical Pharmacology & Therapeutics © 2019 American Society for Clinical Pharmacology and Therapeutics Some patients prescribed flucloxacillin (~0.01%) develop drug-induced liver injury (DILI). HLA-B*57:01 is an established genetic risk factor for flucloxacillin DILI. To consolidate this finding, identify additional genetic factors, and assess relevance of risk factors for flucloxacillin DILI in relation to DILI due to other penicillins, we performed a genomewide association study involving 197 flucloxacillin DILI cases and 6,835 controls. We imputed single-nucleotide polymorphism and human leukocyte antigen (HLA) genotypes. HLA-B*57:01 was the major risk factor (allelic odds ratio (OR)=36.62; P=2.67×10−97). HLA-B*57:03 also showed an association (OR=79.21; P=1.2×10−6). Within the HLA-B protein sequence, imputation showed valine97, common to HLA-B*57:01 and HLA-B*57:03, had the largest effect (OR=38.1; P=9.7×10−97). We found no HLA-B*57 association with DILI due to other isoxazolyl penicillins (n=6) or amoxicillin (n=15) and no significant non-HLA signals for any penicillin-related DILI

A Rare Microsporidial Infection in Lamellar Corneal Tissue, following Transepithelial Photorefractive Keratectomy

The aim of this study was to report a unique case of microsporidial keratitis over deep anterior lamellar keratoplasty after transepithelial photorefractive keratectomy surgery that was successfully treated with therapeutic lamellar keratoplasty without recurrence at King Khaled Eye Specialist Hospital in Riyadh, Saudi Arabia. The patient presented with recurrent attacks of eye pain, redness, photophobia, and decreased vision. The patient was initially treated as a case of presumed herpetic keratouveitis using antiviral medication and topical steroids with partial improvement. During the last episode, the condition deteriorated and patient underwent therapeutic lamellar keratoplasty. Histopathology indicated an infected graft with evidence of microsporidial infection. The patient was discharged with complete corneal epithelial healing and no signs of recurrence during follow-up. Microsporidial infection is a rare cause of stromal keratitis that affects both immunocompetent and immunosuppressed patients. Microsporidia should be suspected after surface ablation refractive surgery if the patient presents with recurrent symptoms of keratoconjunctivitis or stromal keratitis that are partially responsive to topical steroid therapy

Use of Pharmacogenetic Drugs by the Dutch Population

Introduction: The Dutch Pharmacogenetics Working Group (DPWG) indicated a list of actionable genotypes that affect patients' response to more 50 drugs; these drugs which show variable effects based on patients' genetic traits were named as pharmacogenetics (PGX) drugs. Preemptive genetic testing before using these drugs may protect certain patients from serious adverse reactions and could help in avoiding treatment failures. The objectives of this study include identifying the rate of PGX drug usage among Dutch population, estimating the level of users who carry the actionable genotypes and determining the main genes involved in drug's effect variability. Methods: Usage of PGX drugs over 2011-2017 by the insured population (an average of 11.4 million) in outpatient clinics in Netherlands was obtained from the publically available GIP databank. The data of 45 drugs were analyzed and their interactions with selected pharmacogenes were estimated. Frequency of actionable genotypes of 249 Dutch parents was obtained from the public database: Genome of Netherlands (GoNL), to identify the pattern of genetic characteristics of Dutch population. Results: Over a 7 year period, 51.3 million exposures of patients to PGX drugs were reported with an average of 5.3 exposures per each drug user. One quarterof the exposures (12.4 million) are predicted to be experienced by individuals with actionable genotypes (risky exposures). Up to 60% of the risky exposures (around 7.5 million) were related to drugs metabolized by CYP2D6. SLCO1B1, and CYP2C19 were also identified among the top genes affecting response of drugs users (involved in about 22 and 12.4% of the risky exposures, respectively). Cardiovascular medications were the top prescribed PGX drug class (43%), followed by gastroenterology (29%) and psychiatry/neurology medications (15%). Women use more PGX drugs than men (55.8 vs. 44.2%, respectively) with the majority (84%) of users in both sexes are above 45 years. Conclusion: PGX drugs are commonly used in Netherlands. Preemptive panel testing for CYP2D6, SLCO1B1, and CYP2C19 only could be useful to predict 95% of vulnerable patients' exposures to PGX drugs. Future studies to assess the economic impact of preemptive panel testing on patients of older age are suggested

Use of Pharmacogenetic Drugs by the Dutch Population

Introduction: The Dutch Pharmacogenetics Working Group (DPWG) indicated a list of actionable genotypes that affect patients' response to more 50 drugs; these drugs which show variable effects based on patients' genetic traits were named as pharmacogenetics (PGX) drugs. Preemptive genetic testing before using these drugs may protect certain patients from serious adverse reactions and could help in avoiding treatment failures. The objectives of this study include identifying the rate of PGX drug usage among Dutch population, estimating the level of users who carry the actionable genotypes and determining the main genes involved in drug's effect variability. Methods: Usage of PGX drugs over 2011-2017 by the insured population (an average of 11.4 million) in outpatient clinics in Netherlands was obtained from the publically available GIP databank. The data of 45 drugs were analyzed and their interactions with selected pharmacogenes were estimated. Frequency of actionable genotypes of 249 Dutch parents was obtained from the public database: Genome of Netherlands (GoNL), to identify the pattern of genetic characteristics of Dutch population. Results: Over a 7 year period, 51.3 million exposures of patients to PGX drugs were reported with an average of 5.3 exposures per each drug user. One quarterof the exposures (12.4 million) are predicted to be experienced by individuals with actionable genotypes (risky exposures). Up to 60% of the risky exposures (around 7.5 million) were related to drugs metabolized by CYP2D6. SLCO1B1, and CYP2C19 were also identified among the top genes affecting response of drugs users (involved in about 22 and 12.4% of the risky exposures, respectively). Cardiovascular medications were the top prescribed PGX drug class (43%), followed by gastroenterology (29%) and psychiatry/neurology medications (15%). Women use more PGX drugs than men (55.8 vs. 44.2%, respectively) with the majority (84%) of users in both sexes are above 45 years. Conclusion: PGX drugs are commonly used in Netherlands. Preemptive panel testing for CYP2D6, SLCO1B1, and CYP2C19 only could be useful to predict 95% of vulnerable patients' exposures to PGX drugs. Future studies to assess the economic impact of preemptive panel testing on patients of older age are suggested

Two Cases of Recessive Intellectual Disability Caused byNDST1andMETTL23Variants

Intellectual disability (ID) is a highly heterogeneous genetic condition with more than a thousand genes described so far. By exome sequencing of two consanguineous families presenting hallmark features of ID, we identified two homozygous variants in two genes previously associated with autosomal recessive ID:NDST1(c.1966G>A; p.Asp656Asn) andMETTL23(c.310T>C; p.Phe104Leu). The segregation of the variants was validated by Sanger sequencing in all family members. In silico homology modeling of wild-type and mutated proteins revealed substantial changes in the secondary structure of both proteins, indicating a possible effect on function. The identification and validation of new pathogenicNDST1andMETTL23variants in two cases of autosomal recessive ID further highlight the importance of these genes in proper brain function and development

Use of Pharmacogenetic Drugs by the Dutch Population

Introduction: The Dutch Pharmacogenetics Working Group (DPWG) indicated a list of actionable genotypes that affect patients' response to more 50 drugs; these drugs which show variable effects based on patients' genetic traits were named as pharmacogenetics (PGX) drugs. Preemptive genetic testing before using these drugs may protect certain patients from serious adverse reactions and could help in avoiding treatment failures. The objectives of this study include identifying the rate of PGX drug usage among Dutch population, estimating the level of users who carry the actionable genotypes and determining the main genes involved in drug's effect variability. Methods: Usage of PGX drugs over 2011-2017 by the insured population (an average of 11.4 million) in outpatient clinics in Netherlands was obtained from the publically available GIP databank. The data of 45 drugs were analyzed and their interactions with selected pharmacogenes were estimated. Frequency of actionable genotypes of 249 Dutch parents was obtained from the public database: Genome of Netherlands (GoNL), to identify the pattern of genetic characteristics of Dutch population. Results: Over a 7 year period, 51.3 million exposures of patients to PGX drugs were reported with an average of 5.3 exposures per each drug user. One quarterof the exposures (12.4 million) are predicted to be experienced by individuals with actionable genotypes (risky exposures). Up to 60% of the risky exposures (around 7.5 million) were related to drugs metabolized by CYP2D6. SLCO1B1, and CYP2C19 were also identified among the top genes affecting response of drugs users (involved in about 22 and 12.4% of the risky exposures, respectively). Cardiovascular medications were the top prescribed PGX drug class (43%), followed by gastroenterology (29%) and psychiatry/neurology medications (15%). Women use more PGX drugs than men (55.8 vs. 44.2%, respectively) with the majority (84%) of users in both sexes are above 45 years. Conclusion: PGX drugs are commonly used in Netherlands. Preemptive panel testing for CYP2D6, SLCO1B1, and CYP2C19 only could be useful to predict 95% of vulnerable patients' exposures to PGX drugs. Future studies to assess the economic impact of preemptive panel testing on patients of older age are suggested