Pharmacogenetic association between NAT2 gene polymorphisms and isoniazid induced hepatotoxicity: trial sequence meta-analysis as evidence

Effect of NAT2, GSTM1 and CYP2E1 genetic polymorphisms on plasma concentration of isoniazid and its metabolites in patients with tuberculosis, and the assessment of exposure-response relationships

Objectives: Isoniazid is a key drug in the chemotherapy of tuberculosis (TB), however, interindividual variability in pharmacokinetic parameters and drug plasma levels may affect drug responses including drug induced hepatotoxicity. The current study investigated the relationships between isoniazid exposure and isoniazid metabolism-related genetic factors in the context of occurrence of drug induced hepatotoxicity and TB treatment outcomes. Methods: Demographic characteristics and clinical information were collected in a prospective TB cohort study in Latvia (N = 34). Time to sputum culture conversion (tSCC) was used as a treatment response marker. Blood plasma concentrations of isoniazid (INH) and its metabolites acetylisoniazid (AcINH) and isonicotinic acid (INA) were determined at three time points (pre-dose (0 h), 2 h and 6 h after drug intake) using liquid chromatography-tandem mass spectrometry. Genetic variations of three key INH-metabolizing enzymes (NAT2, CYP2E1, and GSTM1) were investigated by application PCR- and Next-generation sequencing-based methods. Depending on variables, group comparisons were performed by Student's t-test, one-way ANOVA, Mann-Whitney-Wilcoxon, and Kruskal-Wallis tests. Pearson correlation coefficient was calculated for the pairs of normally distributed variables; model with rank transformations were used for non-normally distributed variables. Time-to-event analysis was performed to analyze the tSCC data. The cumulative probability of tSCC was obtained using Kaplan-Meier estimators. Cox proportional hazards models were fitted to estimate hazard rate ratios of successful tSCC. Results: High TB treatment success rate (94.1%) was achieved despite the variability in INH exposure. Clinical and demographic factors were not associated with either tSCC, hepatotoxicity, or INH pharmacokinetics parameters. Correlations between plasma concentrations of INH and its metabolites were NAT2 phenotype-dependent, while GSTM1 genetic variants did not showed any effects. CYP2E1*6 (T > A) allelic variant was associated with INH pharmacokinetic parameters. Decreased level of AcINH was associated with hepatotoxicity, while decreased values of INA/INH and AcINH/INH were associated with month two sputum culture positivity. Conclusion: Our findings suggest that CYP2E1, but not GSTM1, significantly affects the INH pharmacokinetics along with NAT2. AcINH plasma level could serve as a biomarker for INH-related hepatotoxicity, and the inclusion of INH metabolite screening in TB therapeutic drug monitoring could be beneficial in clinical studies for determination of optimal dosing strategies.

Association of Cytochrome P450 2E1 and N-Acetyltransferase 2 Genotypes with Serum Isoniazid Level and Anti-Tuberculosis Drug-Induced Hepatotoxicity: A Cross-Sectional Study

Background

Anti-tuberculosis drug-induced hepatotoxicity can result from genetic polymorphism of the isoniazid (INH) metabolizing enzyme. This study aimed to determine the effect of genetic polymorphism of N-acetyltransferase 2 (NAT2) and cytochrome P450 2E1 (CYP2E1) genes on serum isoniazid level and drug-induced hepatotoxicity.

Methods

A cross-sectional study was conducted on 120 patients (with and without hepatotoxicity) with pulmonary tuberculosis from June 2019 to April 2022 in Tehran (Iran). High-performance liquid chromatography was used to measure the serum concentration of INH and acetylisoniazid (AcINH). NAT2 and CYP2E1 genotypes were determined using polymerase chain reaction and restriction fragment length polymorphism methods. Data were analyzed using SPSS software (version 22.0) with independent two-sample t test, Chi square test, or Fisher's exact test. P<0.05 was considered statistically significant.

Results

A total of 40 patients showed hepatotoxicity. The risk of anti-tuberculosis drug-induced hepatotoxicity was significantly higher in patients who are slow acetylator (SA) phenotype than in rapid or intermediate acetylator (P<0.001). NAT2*4/*4 genotypes were not found in patients with hepatotoxicity. The frequency of NAT2*5 and NAT2*6 haplotypes and serum INH concentration was significantly higher in patients with hepatotoxicity than in those without (P=0.003, P<0.001, and P<0.001, respectively). NAT2*4 haplotype was correlated with protection against hepatotoxicity. A combination of SA and CYP2E1 C1/C1 genotype was significantly associated with hepatotoxicity (P<0.001).

Conclusion

Hepatotoxicity in Iranian patients with tuberculosis was confirmed due to the presence of NAT2 SA polymorphism. Determining NAT2 and CYP2E1 genotypes and/or INH concentration can be a valuable tool to identify patients susceptible to hepatotoxicity.

The role of Mycobacterium tuberculosis acetyltransferase and protein acetylation modifications in tuberculosis

Tuberculosis (TB) is a widespread infectious disease caused by Mycobacterium tuberculosis (M. tb), which has been a significant burden for a long time. Post-translational modifications (PTMs) are essential for protein function in both eukaryotic and prokaryotic cells. This review focuses on the contribution of protein acetylation to the function of M. tb and its infected macrophages. The acetylation of M. tb proteins plays a critical role in virulence, drug resistance, regulation of metabolism, and host anti-TB immune response. Similarly, the PTMs of host proteins induced by M. tb are crucial for the development, treatment, and prevention of diseases. Host protein acetylation induced by M. tb is significant in regulating host immunity against TB, which substantially affects the disease's development. The review summarizes the functions and mechanisms of M. tb acetyltransferase in virulence and drug resistance. It also discusses the role and mechanism of M. tb in regulating host protein acetylation and immune response regulation. Furthermore, the current scenario of isoniazid usage in M. tb therapy treatment is examined. Overall, this review provides valuable information that can serve as a preliminary basis for studying pathogenic research, developing new drugs, exploring in-depth drug resistance mechanisms, and providing precise treatment for TB.

Polymorphisms in drug metabolism genes as a risk factor for first-line anti-tuberculosis drug-induced liver injury

BACKGROUND

Anti-tuberculosis drug-induced liver injury (AT-DILI) is one of the most common side effects in TB patients during treatment. The prime cause of liver injury during TB treatment is reported to be isoniazid and its metabolites. Different factors influenced the development of AT-DILI, and genetic factors are one of the major factors.

METHODS AND RESULTS

Polymorphisms in drug metabolism genes like NAT2, CYP2E1, PXR, and GST have been reported to be associated with AT-DILI, and they are one of the major areas of focus at present. Attempts are met in this review to analyse the different markers in these drug metabolism genes for their association with AT-DILI.

CONCLUSION

A better understanding of the polymorphisms in these genes and their functional effects will give better insights into the development of AT-DILI, and it could facilitate in designing and developing more effective personalized treatment for TB.

High Isoniazid Exposures When Administered with Rifapentine Once Weekly for Latent Tuberculosis in Individuals with Human Immunodeficiency Virus

Isoniazid pharmacokinetics are not yet well-described during once weekly, high-dose administrations with rifapentine (3HP) for latent tuberculosis infection (LTBI). Fewer data describe 3HP with dolutegravir-based antiretroviral therapy for the treatment of human immunodeficiency virus (HIV). The only prior report of 3HP with dolutegravir reported elevated isoniazid exposures. We measured the plasma isoniazid levels in 30 adults receiving 3HP and dolutegravir for the treatment of LTBI and HIV. The patients were genotyped to determine NAT2 acetylator status, and a population PK model was estimated by nonlinear mixed-effects modeling. The results were compared to previously reported data describing 3HP with dolutegravir, 3HP alone, and isoniazid with neither dolutegravir nor rifapentine. The isoniazid concentrations were adequately described by a one compartment model with a transit compartment absorption process. The isoniazid clearance for slow (8.33 L/h) and intermediate (12 L/h) acetylators were similar to previously reported values. Rapid acetylators (N = 4) had clearance similar to those of intermediate acetylators and much slower than typically reported, but the small sample size was limiting. The absorption rate was lower than usual, likely due to the coadministration with food, and it was faster among individuals with a low body weight. Low-body weight participants were also observed to have greater oral bioavailability. The isoniazid exposures were consistent with, or greater than, the previously reported "elevated" concentrations among individuals receiving 3HP and dolutegravir. The concentrations were substantially greater than those presented in previous reports among individuals receiving 3HP or isoniazid without rifapentine or dolutegravir. We discuss the implications of these findings and the possibility of a drug-drug interaction that is mediated by cellular transport. (This study has been registered at ClinicalTrials.gov under identifier NCT03435146 and has South African National Clinical Trial Registration no. DOH-27-1217-5770.).

Functional variability of rhesus macaque (Macaca mulatta) NAT2 gene for drug-metabolising arylamine N-acetyltransferase 2

Human NAT2 is a polymorphic pharmacogene encoding for N-acetyltransferase 2, a hepatic enzyme active towards arylamine and arylhydrazine drugs, including the anti-tubercular antibiotic isoniazid. The isoenzyme also modulates susceptibility to chemical carcinogenesis, particularly of the bladder. Human NAT2 represents an ideal model for anthropological investigations into the demographic adaptation of worldwide populations to their xenobiotic environment. Its sequence appears to be subject to positive selection pressures that are population-specific and may be attributed to gene-environment interactions directly associated with exogenous chemical challenges. However, recent evidence suggests that the same evolutionary pattern may not be observed in other primates. Here, we report NAT2 polymorphism in 25 rhesus macaques (Macaca mulatta) and compare the frequencies and functional characteristics of 12 variants. Seven non-synonymous single nucleotide variations (SNVs) were identified, including one nonsense mutation. The missense SNVs were demonstrated to affect enzymatic function in a substrate-dependent manner, albeit more moderately than certain NAT1 SNVs recently characterised in the same cohort. Haplotypic and functional variability of NAT2 was comparable to that previously observed for NAT1 in the same population sample, suggesting that the two paralogues may have evolved under similar selective pressures in the rhesus macaque. This is different to the population variability distribution pattern reported for humans and chimpanzees. Recorded SNVs were also different from those found in other primates. The study contributes to further understanding of NAT2 functional polymorphism in the rhesus macaque, a non-human primate model used in biomedicine and pharmacology, indicating variability in xenobiotic acetylation that could affect drug metabolism.

Oxidative Stress in Drug-Induced Liver Injury (DILI): From Mechanisms to Biomarkers for Use in Clinical Practice

Idiosyncratic drug-induced liver injury (DILI) is a type of hepatic injury caused by an uncommon drug adverse reaction that can develop to conditions spanning from asymptomatic liver laboratory abnormalities to acute liver failure (ALF) and death. The cellular and molecular mechanisms involved in DILI are poorly understood. Hepatocyte damage can be caused by the metabolic activation of chemically active intermediate metabolites that covalently bind to macromolecules (e.g., proteins, DNA), forming protein adducts-neoantigens-that lead to the generation of oxidative stress, mitochondrial dysfunction, and endoplasmic reticulum (ER) stress, which can eventually lead to cell death. In parallel, damage-associated molecular patterns (DAMPs) stimulate the immune response, whereby inflammasomes play a pivotal role, and neoantigen presentation on specific human leukocyte antigen (HLA) molecules trigger the adaptive immune response. A wide array of antioxidant mechanisms exists to counterbalance the effect of oxidants, including glutathione (GSH), superoxide dismutase (SOD), catalase, and glutathione peroxidase (GPX), which are pivotal in detoxification. These get compromised during DILI, triggering an imbalance between oxidants and antioxidants defense systems, generating oxidative stress. As a result of exacerbated oxidative stress, several danger signals, including mitochondrial damage, cell death, and inflammatory markers, and microRNAs (miRNAs) related to extracellular vesicles (EVs) have already been reported as mechanistic biomarkers. Here, the status quo and the future directions in DILI are thoroughly discussed, with a special focus on the role of oxidative stress and the development of new biomarkers.

Arylamine N-acetyltransferase acetylation polymorphisms: paradigm for pharmacogenomic-guided therapy- a focused review

INTRODUCTION

The N-acetylation polymorphism has been the subject of comprehensive reviews describing the role of arylamine N-acetyltransferase 2 (NAT2) in the metabolism of numerous aromatic amine and hydrazine drugs.

AREAS COVERED

We describe and review data that more clearly defines the effects of NAT2 haplotypes and genotypes on the expression of acetylator phenotype towards selected drugs within human hepatocytes in vitro, within human hepatocyte cultures in situ, and clinical measures such as bioavailability, plasma metabolic ratios of parent to N-acetyl metabolite, elimination rate constants and plasma half-life, and/or clearance determinations in human subjects. We review several drugs (isoniazid, hydralazine, sulfamethazine, amifampridine, procainamide, sulfasalazine, amonafide and metamizole) for which NAT2 phenotype-guided therapy may be important. The value of pharmacogenomics-guided isoniazid therapy for the prevention and treatment of tuberculosis is presented as a paradigm for NAT2 phenotype-dependent dosing strategies.

EXPERT OPINION

Studies in human subjects and cryopreserved human hepatocytes show evidence for rapid, intermediate and slow acetylator phenotypes, with further data suggesting genetic heterogeneity within the slow acetylator phenotype. Incorporation of more robust NAT2 genotype/phenotypes relationships, including genetic heterogeneity within the slow acetylator phenotype, should lead to further advancements in both health outcomes and cost benefit for prevention and treatment of tuberculosis.

Genetic Polymorphisms of Delta-Like 1 Homolog Influence the Susceptibility to Antituberculosis Drug-Induced Hepatotoxicity

This study was designed to investigate the relationship between Delta-like 1 homolog (DLK1) polymorphisms and the occurrence of antituberculosis drug-induced hepatotoxicity (ATDH) in the Western Chinese Han population. A total of 746 tuberculosis patients including 118 ATDH cases and 628 non-ATDH cases were enrolled from West China Hospital of Sichuan University during 2016-2018. Ten single nucleotide polymorphisms (rs11160604, rs7149242, rs7141210, rs7155375, rs876374, rs57098752, rs2400940, rs12431758, rs4900472, and rs6575802) within DLK1 were studied by the improved multiplex ligation detection reaction method genotyping technology assay. It was found that G allele of rs11160604 was associated with an increased risk for ATDH (p = 0.001) and G allele of rs4900472 showed a protective effect for ATDH (p = 0.030). Recessive model and dominant model of rs11160604 were observed as a risk factor for ATDH predisposition, whereas the recessive model of rs4900472 was a protective one. Moreover, the interaction genetic model composed of rs11160604, rs57098752, and rs12431758 showed a combined effect for the occurrence of ATDH. Our finding was a novel one indicating that the G allele of DLK1 rs11160604 might serve as a hazard for the development of ATDH in the Western Chinese Han population.

Collagen type XVIII alpha 1 chain (COL18A1) variants affect the risk of anti-tuberculosis drug-induced hepatotoxicity: A prospective study

Background

The role of collagen type XVIII alpha 1 chain (COL18A1) in anti‐tuberculosis drug‐induced hepatotoxicity (ATDH) has not been reported. This study aimed to explore the association between of COL18A1 variants and ATDH susceptibility.

Methods

A total of 746 patients were enrolled in our study from December 2016 to April 2018, and all subjects in the study signed an informed consent form. The custom‐by‐design 2x48‐Plex SNPscanTM kit was used to genotype all selected 11 SNPs. Categorical variables were compared by chi‐square (χ²) or Fisher's exact test, while continuous variables were compared by Mann‐Whitney's U test. Plink was utilized to analyze allelic and genotypic frequencies, and genetic models. Multivariate logistic regression analyses were used to adjust potential factors. The odds ratios (ORs) with corresponding 95% confidence intervals (CIs) were also calculated.

Results

Among patients with successfully genotyping, there were 114 cases and 612 controls. The mutant A allele of rs12483377 conferred the decreased risk of ATDH (OR = 0.13, 95%CI: 0.02–0.98, P = 0.020), and this significance still existed after adjusting age and gender (P = 0.024). The mutant homozygote AA genotype of rs12483377 was associated with decreased total protein levels (P = 0.018).

Conclusion

Our study first revealed that the A allele of COL18A1 rs12483377 was associated with the decreased risk of ATDH in the Western Chinese Han population, providing new perspective for the molecular prediction, precise diagnosis, and individual treatment of ATDH.

Genetic Risk Factors in Drug-Induced Liver Injury Due to Isoniazid-Containing Antituberculosis Drug Regimens

Drug-induced liver injury (DILI) is a complication of treatment with antituberculosis (TB) drugs, especially in isoniazid (INH)-containing regimens. To investigate genetic risk factors, we performed a genomewide association study (GWAS) involving anti-TB DILI cases (55 Indian and 70 European) and controls (1,199 Indian and 10,397 European). Most cases were treated with a standard anti-TB drug regimen; all received INH. We imputed single nucleotide polymorphism and HLA genotypes and performed trans-ethnic meta-analysis on GWAS and candidate gene genotypes. GWAS found one significant association (rs117491755) in Europeans only. For HLA, HLA-B*52:01 was significant (meta-analysis odds ratio (OR) 2.67, 95% confidence interval (CI) 1.63-4.37, P = 9.4 × 10^-5 ). For N-acetyltransferase 2 (NAT2), NAT2*5 frequency was lower in cases (OR 0.69, 95% CI 0.57-0.83, P = 0.01). NAT2*6 and NAT2*7 were more common, with homozygotes for NAT2*6 and/or NAT2*7 enriched among cases (OR 1.89, 95% CI 0.84-4.22, P = 0.004). We conclude HLA genotype makes a small contribution to TB drug-related DILI and that the NAT2 contribution is complex, but consistent with previous reports when differences in the metabolic effect of NAT2*5 compared with those of NAT2*6 and NAT2*7 are considered.

Current Perspective: 3D Spheroid Models Utilizing Human-Based Cells for Investigating Metabolism-Dependent Drug-Induced Liver Injury

Drug-induced liver injury (DILI) remains a leading cause for the withdrawal of approved drugs. This has significant financial implications for pharmaceutical companies, places increasing strain on global health services, and causes harm to patients. For these reasons, it is essential that in-vitro liver models are capable of detecting DILI-positive compounds and their underlying mechanisms, prior to their approval and administration to patients or volunteers in clinical trials. Metabolism-dependent DILI is an important mechanism of drug-induced toxicity, which often involves the CYP450 family of enzymes, and is associated with the production of a chemically reactive metabolite and/or inefficient removal and accumulation of potentially toxic compounds. Unfortunately, many of the traditional in-vitro liver models fall short of their in-vivo counterparts, failing to recapitulate the mature hepatocyte phenotype, becoming metabolically incompetent, and lacking the longevity to investigate and detect metabolism-dependent DILI and those associated with chronic and repeat dosing regimens. Nevertheless, evidence is gathering to indicate that growing cells in 3D formats can increase the complexity of these models, promoting a more mature-hepatocyte phenotype and increasing their longevity, in vitro. This review will discuss the use of 3D in vitro models, namely spheroids, organoids, and perfusion-based systems to establish suitable liver models to investigate metabolism-dependent DILI.

Effects of a new 1,2,3-thiadiazole containing hydrazone antimycobacterial agent on serum and liver biochemical parameters in female mice

Isoniazid (INH), a first-line drug in anti-tuberculosis therapy, is known to be potentially harmful and is associated with numerous side effects especially in the blood and liver. In the course of our previous investigations, 1,2,3-thiadiazole containing hydrazone (compound 3) showed excellent antimycobacterial activity against a referent strain M. tuberculosis H37Rv (MIC value 0.39 μM), low cytotoxicity, and did not have toxic effects when administered by oral or intraperitoneal routes to experimental animals (selectivity index SI > 1979, LD₅₀>2000 mg/kg b.w.) what revealed its suitability for further exploration. In the present study compound 3 was chosen to determine its effects on the liver and kidney functions in female mice. The compound was administered orally for 14 days at three doses (100, 200, and 400 mg/kg b.w.). The quantity of malondialdehyde (MDA), the level of reduced glutathione (GSH), blood hematological and biochemical parameters were assessed, and urine analysis was carried out. As a positive control INH was used orally at a dose of 50 mg/kg b.w. The investigated compound 3 did not affect the urine and serum hematological and biochemical parameters as INH did, compared to those of the control mice. The new compound did not affect significantly the MDA quantity and maintained its level near to the control values, though lower by 36% (p < 0.05) than in the INH treated animals. At the higher doses, 200 and 400 mg/kg, it depleted the GSH content by 25% (p < 0.05), compared to the control. However, its level remained 47% (p < 0.05) higher than in the INH treated animals.

Association of genetic polymorphisms of CYP2E1, NAT2, GST and SLCO1B1 with the risk of anti-tuberculosis drug-induced liver injury: a systematic review and meta-analysis

OBJECTIVES

The objective of this study was to investigate the association between genetic polymorphisms of N-acetyltransferase 2 (NAT2), cytochrome P450 2E1 (CYP2E1), glutathione S-transferase (GST) and solute carrier organic anion transporter family member 1B1 (SLCO1B1) and the risk of anti-tuberculosis drug-induced liver injury (ATDILI).

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

PubMed, Embase, Web of Science and Cochrane Reviews databases were searched through April 2019.

ELIGIBILITY CRITERIA

We included case-control or cohort studies investigating an association between NAT2, CYP2E1, GST or SLCO1B1 polymorphisms and the ATDILI risk in patients with tuberculosis.

DATA EXTRACTION AND SYNTHESIS

Three authors screened articles, extracted data and assessed study quality. The strength of association was evaluated for each gene using the pooled OR with a 95% CI based on the fixed-effects or random-effects model. Sensitivity analysis was performed to confirm the reliability and robustness of the results.

RESULTS

Fifty-four studies were included in this analysis (n=26 for CYP2E1, n=35 for NAT2, n=19 for GST, n=4 for SLCO1B1). The risk of ATDILI was significantly increased with the following genotypes: CYP2E1 RsaI/PstI c1/c1 (OR=1.39, 95% CI 1.06 to 1.83), NAT2 slow acetylator (OR=3.30, 95% CI 2.65 to 4.11) and GSTM1 null (OR=1.30, 95% CI 1.12 to 1.52). No significant association with ATDILI was found for the genetic polymorphisms of CYP2E1 DraI, GSTT1, GSTM1/GSTT1, SLCO1B1 388A>G and SLCO1B1 521T>C (p>0.05).

CONCLUSIONS

ATDILI is more likely to occur in patients with NAT2 slow acetylator genotype, CYP2E1 RsaI/PstI c1/c1 genotype and GSTM1 null genotype. Close monitoring may be warranted for patients with these genotypes.