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Analysis of IL-6, STAT3 and HSPA1L Gene Polymorphisms in Anti-Tuberculosis Drug-Induced Hepatitis in a Nested Case-Control Study

  • Jing Wang,

    Affiliation Department of Epidemiology and Biostatistics, School of Public Health, Peking University Health Science Centre, Beijing, China

  • Ru Chen,

    Affiliation Department of Epidemiology and Biostatistics, School of Public Health, Peking University Health Science Centre, Beijing, China

  • Shaowen Tang,

    Affiliations Department of Epidemiology and Biostatistics, School of Public Health, Peking University Health Science Centre, Beijing, China, Department of Epidemiology and Biostatistics, School of Public Health, Nanjing Medical University, Nanjing, China

  • Xiaozhen Lv,

    Affiliation Clinical Research Division, Peking University Institute of Mental Health, and Key Laboratory for Mental Health, Ministry of Health, Beijing, China

  • Shanshan Wu,

    Affiliation Department of Epidemiology and Biostatistics, School of Public Health, Peking University Health Science Centre, Beijing, China

  • Yuan Zhang,

    Affiliation Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Canada

  • Yinyin Xia,

    Affiliation Center for Tuberculosis Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China

  • Pei Gao,

    Affiliation Department of Epidemiology and Biostatistics, School of Public Health, Peking University Health Science Centre, Beijing, China

  • Dehua Tu,

    Affiliation Department of Tuberculosis Treatment, Beijing Institute for Tuberculosis Control, Beijing, China

  • Dafang Chen,

    Affiliation Department of Epidemiology and Biostatistics, School of Public Health, Peking University Health Science Centre, Beijing, China

  • Siyan Zhan

    siyan-zhan@bjmu.edu.cn

    Affiliation Department of Epidemiology and Biostatistics, School of Public Health, Peking University Health Science Centre, Beijing, China

Abstract

Objectives

To investigate the association of IL-6, STAT3 and HSPA1L polymorphisms with the risk of anti-tuberculosis drug-induced hepatitis (ATDH) in Chinese Han population.

Methods

The study was designed as a nested case-control study within a prospective cohort. Each case was matched with four controls by sex, age at baseline (±5 years), treatment history, disease severity, drug dosage and place of sample collection. Genetic polymorphisms of IL-6, STAT3 and HSPA1L were determined blindly by TaqMan single-nucleotide polymorphism (SNP) genotyping assay. Odds ratio (OR) with 95% confidence intervals (CIs) was estimated by conditional logistic regression model to measure the association between selected SNPs and the risk of ATDH.

Results

A total of 89 incident ATDH cases and 356 ATDH-free controls were genotyped for IL-6 (rs2066992, rs2069837, rs1524107), STAT3 (rs1053004, rs1053023, rs1053005) and HSPA1L (rs2227956). In genotype analysis, no significant difference was observed in genotypes frequencies of the seven selected SNPs between case and control group after Bonferroni correction. In haplotype analysis, carriers with STAT3 GAT and AGC (rs1053023-rs1053005-rs1053004) haplotypes had a significantly higher risk of ATDH compared with wild-type haplotype (P<0.0001).

Conclusion

This study suggested that genetic variants of STAT3 might contribute to ATDH susceptibility in Chinese Han population. Studies in larger, varied populations are required to confirm these findings.

Introduction

Tuberculosis (TB) remains a major global health problem, causing ill-health among millions of people each year and ranking as the second leading cause of death from infectious diseases worldwide. According to World Health Organization (WHO) report, there were 8.6 million new cases in 2012 and China alone accounted for 12% of total cases behind India [1].

In order to control TB epidemic, directly observed treatment strategy (DOTS) therapy has been implemented in China, which is a standard chemotherapy regimen requiring continually taking drug combinations of isoniazid (INH), rifampicin (RIF), pyrazinamide (PZA), ethambutol (EMB) and/or streptomycin (SM) for six to nine months [2]. Although a vast majority of patients tolerate the drugs, the outcome may be less favorable in those with undesirable adverse drug reactions (ADRs). Anti-tuberculosis drug-induced hepatitis (ATDH) as one of the most serious ADRs would not only increase the suffering of the patients, but also cause incompliance, drug resistance and even treatment failure [3,4]. Therefore, efforts to enhance the understanding of the risk factors and pathogenesis of ATDH are urgently needed.

Risk factors associated with ATDH include female sex, older age, pre-existing liver disease, heavy alcohol consumption, and HIV or hepatitis B or C virus co-infection [5]. In addition, genetic factors contributing to the susceptibility of ATDH involving genetic variations in drug metabolism, drug transport, acquired immune responses have been studied extensively [6,7,8,9]. However, the the roles of cytokines in ATDH still remain largely uncharacterized.

Limited studies have investigated the association between cytokine genetic polymorphisms and the risk of drug induced liver injury (DILI). Aithal [10] reported that the frequencies of the variant alleles for IL-10 and IL-4 were significant higher in patients with diclofenac-induced hepatitis compared with both healthy controls and subjects on diclofenac without hepatitis. Kim [11] revealed that TNF-∝ polymorphism-308G/A was significantly associated with ATDH (OR = 1.95 95% CI 1.11–3.14). Liang [12] found that IL-10–592 AA and IL-10–819 TT genotypes significantly increased the incidence of DILI in breast cancer patients. However, controversial results were reported in another study [13]. Taken together, all these studies suggested that cytokine genetic polymorphisms may contribute to the risk of DILI.

Among the numerous cytokines relevant to DILI susceptibility and progression, there is compelling evidence that Interleukin-6 (IL-6) plays an important role in acute phase response, liver regeneration and protection against liver injury by a variety of drugs [14,15,16]. It is also well known that the protective effect of IL-6 is mediated through IL-6/STAT3 signaling pathway which provides hepatoprotection against Fas and toxic damage by direct inactivation of caspases and reduction of reactive oxygen species [17,18]. Previous study also found that IL-6 may protect against DILI by up-regulating the heat shock protein (HSP) expression [19], and HSPs protect against apoptosis, necrosis [20] and toxin insult [21]. HSPs are a group of conserved proteins expressed ubiquitously in cells and the HSP70 family (70kD HSP) is probably the most predominant among all HSP proteins [22]. Some experimental studies have proved the liver protection role of HSP70 genes against hepatotoxic agents by protecting mitochondria and interfering with the stress-induced apoptotic program [23,24]. Genetic association studies also found that HSP70 polymorphisms were associated with many diseases such as hepatocellular cancer, breast cancer, gastric cancer and Crohn’s disease in Chinese population [25,26]. Therefore, we hypothesized that IL-6/STAT3 pathway and the downstream HSP70 responsiveness may contribute to the IL-6-mediated protective effect against DILI.

To our knowledge, there was only one case-control study with 37 patients and 32 controls found that IL-6 polymorphisms/haplotypes were associated with the risk of tacrine-induced liver injury [27]. And one GWAS study [28] in patients taking flucloxacillin observed a significant difference between cases and controls in HSPA1L rs2227956, however these associations have not been investigated in ATDH patients. And there is no published study investigating the association of genetic variants of STAT3 gene with susceptibility of ATDH.

This study is the first attempt aiming to investigate the association of IL-6, STAT3 and HSPA1L polymorphisms with the risk of ATDH in Chinese Han population.

Materials and Methods

Study population

This case-control study was nested in a cohort study entitled Anti-tuberculosis Drugs Induced Adverse Reactions in China National Tuberculosis Prevention and Control Scheme Study (ADACS) [29]. This study was approved by the Ethics Committee of Center for Tuberculosis Control and Prevention of China and Health Science Center of Peking University. Written informed consent was obtained from every participant or surrogate before enrolment. From October 2007 to June 2008, a total of 4488 newly diagnosed patients with sputum smear positive pulmonary TB were recruited from four provinces (Zhejiang, Guangxi, Chongqing, Jilin) in China. Some characteristics of this cohort have been reported previously [30,31]. Patients were excluded for the following reasons: 1) abnormal serum ALT, AST or total bilirubin levels before anti-TB treatment; 2) positive serological testing for hepatitis B virus; 3) concomitant use of hepatotoxic drugs or regular alcohol intake; 4) history of liver disease or systemic diseases that may cause liver dysfunction.

All primary/retreatment patients with pulmonary TB were treated with a combination regimen including INH (600 mg), RIF (600 mg, or 450 mg if body weight was < 50 kg), PZA (2000 mg) and EMB (1250 mg) for the first two months (retreatment patients were injected with SM 750 mg each time simultaneously) and then with the same regimen, without PZA and EMB, for another four months for primary patients and with the same regimen, without PZA and SM, for another six months for retreatment patients. Doses did not vary with ages and sex. Before anti-tuberculosis treatment, serum hepatitis B virus surface antigen (HBsAg), serum alanine transaminase (ALT), aspartate amino transaminase (AST), direct and total bilirubin levels, renal function, blood and urine routine test were measured and these tests were conducted again within two months after the onset of treatment or whenever patients had symptoms of suspected hepatitis (such as anorexia, nausea, vomiting, malaise, tea-colored urine) [32].

ATDH was defined as: 1) an increase in ALT level greater than two-times of the upper limit of normal (ULN) with/without a combined increase in AST and total bilirubin levels provided one of them was greater than two-times of ULN during the treatment [33]; 2) causality assessment result was certain, probable or possible based on the WHO Uppsala Monitoring Center system [34]. All suspected hepatitis patients were reviewed by experts from Chinese State Food and Drug Administration. Patients who fulfilled the criteria of ATDH were assigned into the case group, and each case was matched with four ATDH-free controls by sex, age at baseline (±5 years), treatment history (categorized as primary treatment patients and retreatment patients), disease severity (based on the range of lesions on X-ray films and categorized as minimal, moderately and far advanced on the basis of the National Tuberculosis Association of USA [35]), drug dosage and place of sample collection.

SNPs selection

For the replication purpose, the public SNP database (NCBI dbSNP) and Pubmed were searched to identify previously reported genetic polymorphisms of candidate gene IL-6, STAT3 and HSP70 in association with DILI. Then, SNPs were selected if the minor allele frequencies (MAF) in Chinese Han population was > = 0.10. As a result, three SNPs were selected which were rs2066992 and rs2069837 for IL-6 and rs2227956 for HSPA1L (Table 1).

For gene STAT3, as there is no report previously, SNPs were selected based on tag SNP (tSNP). For IL-6 gene, as the selected two SNPs were not functional SNPs, we also select SNPs based on tSNP approach as a supplement. All eligible SNPs including 2kb upstream and downstream of STAT3 were downloaded from the Chinese Han population (CHB) database of HapMap (http://www.hapmap.org/). Then, tSNPs were selected using Haploview 4.2 software according to the following criteria: 1) MAF > = 0.10; 2) r2 of pairwise linkage disequilibrium > = 0.8. As a result, three SNPs (rs1053004, rs1053023, rs1053005) of STAT3 and three SNPs (rs2066992, rs2069837, rs1524107) of IL-6 were selected for genotyping (Table 1).

Genotyping

Genomic DNA was extracted from blood. Genotyping was performed by TaqMan allelic discrimination technology on the ABI 7900 Real-Time PCR System (Applied Biosystems, Foster City, CA, USA) [36]. The primers and probes for each SNP were designed by Nanjing Steed BioTechnologies Co., Ltd (Table A in S1 File). The quality and potential misclassification of the genotyping results were assessed by evaluating 5% of duplicate DNA samples that were randomly selected from the whole samples. Their replicates were 100% concordant. The samples were tested blindly and genotyping results were judged by two researchers independently.

Statistical analyses

Continuous variables were described as mean ± standard deviation (SD) or median (inter-quartile range, IQR) and differences between groups were analyzed by two-factor analysis of variance test or non-parametric test. Categorized variables were described as percentage and analyzed by χ2-test. Hardy-Weinberg equilibrium (HWE) was tested by a goodness-of-fit χ2-test. Haplotype blocks were selected by Haploview 4.2 software in consideration of the linkage disequilibrium (LD) between SNPs in each gene. The estimated frequency of polymorphic loci was calculated using PHASE 2.1 software. Odds ratios (OR) with 95% confidence intervals (CIs) was estimated by conditional logistic regression model. The statistical analyses were performed with SPSS for Windows (version 20.0, SPSS Inc., Chicago, IL, USA). Considering the potential false positive rate incurred by multiple comparisons of SNPs, we applied the Bonferroni correction method to adjust the P value. Sensitivity analysis was further performed to estimate the possible bias due to over-matching based on unmatched cases and controls.

Power calculation was performed for variant alleles using Quanto software package (Version 1.2.4, http://biostats.usc.edu/software). Case-to-control ratio of 1:4, gene only hypothesis, dominant inheritance model were used. We assumed a population risk of 0.12 for ATDH based on a systematic review [37] and considered a genetic relative risk (RG) of 2 with a two-sided p-value of 0.05.

Results

Baseline characteristics

The baseline characteristics of the 89 cases and 356 controls are summarized in Table 2. No significant difference was observed between the two groups regarding to demographic parameters, including age, weight or body mass index and baseline values of liver biochemical parameters (P>0.05). However, the peak AST, ALT, and total bilirubin levels of cases were significantly higher than controls during the treatment (P<0.0001). Of the 89 ATDH cases, 79 had over two times of ULN increased in ALT level and 10 combined an increase in AST and total bilirubin with at least one of them over two times of ULN.

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Table 2. Characteristics of patients with and without ATDH.

https://doi.org/10.1371/journal.pone.0118862.t002

IL-6, STAT3 and HSPA1L polymorphism in patients with and without ATDH

No deviation from Hardy-Weinberg equilibrium was observed for these seven polymorphisms in the controls (P >0.05) (Table 1). The genotype distributions of the selected SNPs in the case and control groups were presented in Table 3. The conditional logistic regression analysis revealed that no significant association was found between three IL-6 SNPs and ATDH. For STAT3 gene, rs1053023 was observed to associate with the risk of ATDH under an additive model, however this significance disappeared after Bonferroni correction. HSPA1L rs2227956 was also not associated with the risk of ATDH after Bonferroni correction (Table 3).

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Table 3. IL-6, STAT3 and HSPA1L Polymorphisms in Patients with and without ATDH.

https://doi.org/10.1371/journal.pone.0118862.t003

Haplotype analysis of IL-6 and STAT3 in patients with and without ATDH

Linkage disequilibrium (LD) analysis was carried out on three SNPs of IL-6 and three SNPs of STAT3. In IL-6, strong LD between rs2069837, rs1524107 and rs2066992 was observed (D’>0.98, r2>0.74), thus we performed a haplotype analysis based on these three SNPs. In STAT3, strong LD between rs1053023, rs1053005 and rs1053004 was also observed (D’>0.95, r2>0.68). Results of haplotypes of these SNPs with risk of ATDH were listed in Table 4. The distribution of IL-6 haplotypes were similar in cases and controls. For gene STAT3, compared with those carrying rs1053023-rs1053005-rs1053004 AAT haplotype, those with rs1053023-rs1053005-rs1053004 GAT and AGC haplotypes were at a significantly increased risk of ATDH with ORs 12.38 (95% CI, 6.40–23.93, P<0.0001) and 20.81 (95% CI, 5.64–76.70, P<0.0001) respectively, after Bonferroni correction.

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Table 4. ORs and 95% CIs for ATDH in relation to IL-6 and STAT3 haplotypes.

https://doi.org/10.1371/journal.pone.0118862.t004

Discussion

In this study, we tested the hypothesis that IL-6/STAT3 signaling pathway and the downstream HSP responsiveness may associate with the development of ATDH. Our result showed that although no significant difference in IL-6 and HSPA1L polymorphisms was observed between ATDH cases and controls, carriers of STAT3 rs1053023-rs1053005-rs1053004 GAT and AGC haplotypes were at a higher risk of ATDH, indicating that STAT3 might play a role in ATDH development.

Recent evidence from animal studies suggested that IL-6-deficient mice exhibit impaired liver regeneration characterized by liver necrosis, a blunted DNA synthesis response in hepatocytes, and reduced gene induction of the G1 phase [38]. By contrast, administration of IL-6 has been shown to serve key hepatoprotective functions against liver injury induced by Concanavalin A [39] and ischemia/reperfusion [40]. The relevance of these observations is still unclear in humans due to the rarity of studies. There was only one small case-control study involving 37 patients who suffered from transaminase elevation after tacrine administration and 32 controls treated with tacrine without experiencing hepatotoxicity, in which the authors investigated the role of IL-6 variants and tacrine-induced hepatotoxicity [27]. Another study in patients with a history of acetaminophen overdose found that levels of IL-6 were higher in patients with serum alanine aminotransferase > 1000 IU/L [41]. However, no other published studies have investigated the association between IL-6 polymorphisms and the risk of ATDH. Our study failed to find the significant association of IL-6 polymorphism with the risk of ATDH. The lack of significant association might be explained by the heterogeneity of culprit drugs and racial differences. In addition, some SNPs (such as rs1800796, rs1800795) in association with various diseases in Chinese population were not included, indicating that genotyping the cases and controls for other SNPs in IL-6 gene might be needed in the future.

As a member of signal transducers and activators of transcription (STATs) family, STAT3 mainly activated by IL-6 is a vital transcription factor providing hepatoprotection against Fas-mediated apoptotic liver damage by two mechanisms: direct inactivation of caspases and reduction of reactive oxygen species [18]. In the classical activation pathway, drug-induced stress and/or damage of hepatocytes may trigger inflammatory responses within the liver, thus it would produce a range of inflammatory mediators, including cytokines like IL-4, IL-6, IL-10 and TNF-∝. It is believed that the protective effect of IL-6 is mediated through binding to its soluble receptor sIL-6R, followed by dimerization of the gp130 protein and activation of the Janus kinase (JAK)-STAT3 signaling pathway. Dimerized STAT3 is able to translocate into the nucleus and activate gene transcription [12]. In addition, several STAT3 downstream genes including HSP70, Bcl-2, Bcl-xL, Mcl-1, FLIP, Ref-1, cyclin D1 and c-myc have been shown to have hepatoprotective effect [18,42].

Li [43] created liver-specific STAT3 deletion mice and reported that these mice exhibited reduced hepatocyte DNA synthesis and lower expression level of G1-phase cyclins, including cyclin D1 and E in the liver. From these results, they concluded that STAT3 accounts for at least part of cell cycle progression and cell proliferation during liver regeneration. Recently, a genome-wide association study in European descent found STAT4 (rs7574865) polymorphism associated with hepatocellular DILI, indicating the emerging role of STAT3 family in the etiology of DILI [44]. In our study, we found that carriers of STAT3 rs1053023-rs1053005-rs1053004 GAT and AGC haplotypes were at a higher risk of ATDH, however, our study on STAT3 AGC haplotype involved comparison of small groups of cases and controls which raised concerns about the observed low P value being simply change finding, therefore, this positive result needs to be confirmed in studies with larger sample size. Moreover, STAT3 could also be activated by several other factors including IL-22, IL-10, ECG and hepatitis viral proteins [45], suggesting that further well designed studies should be conducted to explore the association between them and the risk of ATDH.

Heat shock proteins (HSP) are produced by both prokaryotic and eukaryotic cells in response to a wide variety of stressful insults such as hypoxia, ischaemia, metabolic disruption and inflammatory mediators [46]. HSP70s perform housekeeping and quality controls in cells [47]. The first study to link hepatoprotective role of IL-6 and HSP70 expression was conducted by Masubuchi [19]. They found that the inducible HSP70 in the liver of IL-6-/- mice was impaired when compared with wild-type mice following APAP treatment. In our study, for the purpose of replication in Chinese population, we only chose the reported SNP of HSPA1L gene (rs2227956), which is reported to be significantly associated with increased levels of serum HSP70[48,49],and we found that HSPA1L rs2227956 was not associated with the risk of ATDH after Bonferroni correction. The same polymorphism was found to be associated with Flucloxacillin-induced hepatitis, but it was attributed to its LD with nearby HLA-B genes (B*57:01 allele) [28], which was in part consistent with our finding. Therefore, further investigations focusing on HLA class I and II alleles might be needed in our population.

To the best of our knowledge, this is the first attempt to evaluate the association between variations in IL-6, STAT3 and HSPA1L genes and ATDH in Chinese Han population, which contributes to the further understanding of underlying mechanism in the pathogenesis of ATDH. In addition, our study was based on a well-designed prospective cohort which was the first population based study in China to investigate ADRs among TB patients during anti-TB treatment. All study participants were ethnic Chinese minimizing the potential confounding due to ethnics. Besides, only incident cases were included, thus it ruled out the possibility of recall and selection bias. All ATDH cases were carefully verified by experts which minimized the diagnosis misclassification.

There were also some limitations. Firstly, in our study, cases were matched with four controls based on sex, age at baseline (±5 years), treatment history, disease severity, drug dosage and place of sample collection, which may lead to the problem of over-matching. Therefore, we did a sensitivity analysis based on unmatched cases and controls and no major difference from the main analyses was observed (Table B and C in S1 file). Another limitation is the small sample size, which is because some patients with HBsAg (+), alcohol drinking, liver diseases, and so on were excluded from this study. However, in our study, the statistical power for the given sample size demonstrated that all the analyses were not underpowered (above 80%), indicating that the sample size in our study was adequate to detect the association between the selected SNPs and ATDH (Table D in S1 file). In addition, we did not test for HCV infection, so we cannot rule out the possible confounding, although the prevalence of HCV infection is very low in the study population [50] and we did take the participants’ history of liver disease into consideration. Genetic associations were ethnicity-specific, indicating that a significant association between a specific drug and a specific adverse reaction may not generalize from one ethic group to another. Thus, this positive association should be re-examined in other ethnics.

Conclusion

This study suggested that genetic variants of STAT3 might contribute to ATDH susceptibility in Chinese Han population. Studies in larger, varied populations are required to confirm these findings.

Supporting Information

S1 File. Contains the following files.

Table A. Information of primers and probes. Table B. IL-6, STAT3 and HSPA1L Polymorphisms in Patients with and without ATDH (unmatched case-control study). Table C. ORs and 95% CIs for ATDH in relation to IL-6 and STAT3 haplotypes (unmatched case-control study). Table D. Power calculation results.

https://doi.org/10.1371/journal.pone.0118862.s001

(DOCX)

Acknowledgments

We are grateful to all cooperating organizations (Center for Disease and Control Prevention in Zhejiang, Chongqing, Guangxi and Jilin Provinces) and their staffs whose hard work made this study possible. Special thanks to TB patients participating in this study.

Author Contributions

Conceived and designed the experiments: JW RC SWT XZL YZ SYZ. Performed the experiments: JW RC SWT. Analyzed the data: JW RC SWT PG. Wrote the paper: JW SWT SSW SYZ. Critical review of the manuscript: DFC SYZ. Critical review and assess of ATDH patients: YYX DHT SYZ.

References

  1. 1. World Health Organization. WHO Global tuberculosis report 2013. Euro Surveill. 2013; 18.
  2. 2. World Health Organization. An expanded DOTS framework for effective tuberculosis control. Int J Tuberc Lung Dis 2002; 6:378–388. pmid:12019913
  3. 3. Kaona FA, Tuba M, Siziya S, Sikaona L. An assessment of factors contributing to treatment adherence and knowledge of TB transmission among patients on TB treatment. BMC Public Health. 2004; 4: 68. pmid:15625004
  4. 4. Awofeso N. Anti-tuberculosis medication side-effects constitute major factor for poor adherence to tuberculosis treatment. Bull World Health Organ. 2008; 86: B–D. pmid:19142283
  5. 5. Saukkonen JJ, Cohn DL, Jasmer RM, Schenker S, Jereb JA, Nolan CM, et al. An official ATS statement: hepatotoxicity of antituberculosis therapy. Am J Respir Crit Care Med. 2006; 174: 935–952. pmid:17021358
  6. 6. Daly AK, Aithal GP, Leathart JB, Swainsbury RA, Dang TS, Day CP. Genetic susceptibility to diclofenac-induced hepatotoxicity: contribution of UGT2B7, CYP2C8, and ABCC2 genotypes. Gastroenterology. 2007; 132: 272–281. pmid:17241877
  7. 7. Huang YS, Chern HD, Su WJ, Wu JC, Lai SL, Yang SY, et al. Polymorphism of the N-acetyltransferase 2 gene as a susceptibility risk factor for antituberculosis drug-induced hepatitis. Hepatology. 2002; 35: 883–889. pmid:11915035
  8. 8. Lee SW, Chung LS, Huang HH, Chuang TY, Liou YH, Wu LS. NAT2 and CYP2E1 polymorphisms and susceptibility to first-line anti-tuberculosis drug-induced hepatitis. Int J Tuberc Lung Dis. 2010; 14: 622–626. pmid:20392357
  9. 9. Ohno M, Yamaguchi I, Yamamoto I, Fukuda T, Yokota S, Maekura R, et al. Slow N-acetyltransferase 2 genotype affects the incidence of isoniazid and rifampicin-induced hepatotoxicity. Int J Tuberc Lung Dis. 2000; 4: 256–261. pmid:10751073
  10. 10. Aithal GP, Ramsay L, Daly AK, Sonchit N, Leathart JB, Alexander G, et al. Hepatic adducts, circulating antibodies, and cytokine polymorphisms in patients with diclofenac hepatotoxicity. Hepatology. 2004; 39: 1430–1440. pmid:15122773
  11. 11. Kim SH, Kim SH, Yoon HJ, Shin DH, Park SS, Kim YS, et al. TNF-alpha genetic polymorphism-308G/A and antituberculosis drug-induced hepatitis. Liver Int. 2012; 32: 809–814. pmid:22151084
  12. 12. Liang X, Zhang J, Zhu Y, Lu Y, Zhou X, Wang Z, et al. Specific genetic polymorphisms of IL10–592 AA and IL10–819 TT genotypes lead to the key role for inducing docetaxel-induced liver injury in breast cancer patients. Clin Transl Oncol. 2013; 15: 331–334. pmid:23143946
  13. 13. Pachkoria K, Lucena MI, Crespo E, Ruiz-Cabello F, Lopez-Ortega S, Fernandez MA, et al. Analysis of IL-10, IL-4 and TNF-alpha polymorphisms in drug-induced liver injury (DILI) and its outcome. J Hepatol. 2008; 49: 107–114. pmid:18485518
  14. 14. Sun R, Tian Z, Kulkarni S, Gao B. IL-6 prevents T cell-mediated hepatitis via inhibition of NKT cells in CD4+ T cell- and STAT3-dependent manners. J Immunol. 2004; 172: 5648–5655. pmid:15100309
  15. 15. Gao B. Cytokines, STATs and liver disease. Cell Mol Immunol. 2005; 2: 92–100. pmid:16191414
  16. 16. Li W, Liang X, Kellendonk C, Poli V, Taub R. STAT3 contributes to the mitogenic response of hepatocytes during liver regeneration. J Biol Chem. 2002; 277: 28411–28417. pmid:12032149
  17. 17. Hong F, Kim WH, Tian Z, Jaruga B, Ishac E, Shen X, et al. Elevated interleukin-6 during ethanol consumption acts as a potential endogenous protective cytokine against ethanol-induced apoptosis in the liver: involvement of induction of Bcl-2 and Bcl-x(L) proteins. Oncogene. 2002; 21: 32–43. pmid:11791174
  18. 18. Taub R. Hepatoprotection via the IL-6/Stat3 pathway. J Clin Invest. 2003; 112: 978–980. pmid:14523032
  19. 19. Masubuchi Y, Bourdi M, Reilly TP, Graf ML, George JW, Pohl LR. Role of interleukin-6 in hepatic heat shock protein expression and protection against acetaminophen-induced liver disease. Biochem Biophys Res Commun. 2003; 304: 207–212. pmid:12705907
  20. 20. Didelot C, Schmitt E, Brunet M, Maingret L, Parcellier A, Garrido C. Heat shock proteins: endogenous modulators of apoptotic cell death. Handb Exp Pharmacol. 2006: 171–198. pmid:16610360
  21. 21. Chiu H, Brittingham JA, Laskin DL. Differential induction of heme oxygenase-1 in macrophages and hepatocytes during acetaminophen-induced hepatotoxicity in the rat: effects of hemin and biliverdin. Toxicol Appl Pharmacol. 2002; 181: 106–115. pmid:12051994
  22. 22. Sliwinska-Kowalska M, Pawelczyk M. Contribution of genetic factors to noise-induced hearing loss: a human studies review. Mutat Res. 2013; 752: 61–65. pmid:23207014
  23. 23. Song JY, Li L, Ahn JB, Park JG, Jo JS, Park DH, et al. Acute liver toxicity by carbon tetrachloride in HSP70 knock out mice. Exp Toxicol Pathol. 2007; 59: 29–34. pmid:17582750
  24. 24. Rokutan K. Role of heat shock proteins in gastric mucosal protection. J Gastroenterol Hepatol. 2000; 15 Suppl: D12–D19. pmid:10759215
  25. 25. He L, Deng T, Luo HS. Heat Shock Protein 70 Gene Polymorphisms and Cancer Risk: A Meta-Analysis. Scientific World Journal. 2014; 2014: 540309. pmid:25143984
  26. 26. Chen J, Ren J, Gu G, Wang G, Wu X, Yan D, et al. Crohn’s disease and polymorphism of heat shock protein gene HSP70–2 in the Chinese population. J Gastroenterol Hepatol. 2013; 28: 814–818. pmid:23425104
  27. 27. Carr DF, Alfirevic A, Tugwood JD, Barratt BJ, Sherwood J, Smith J, et al. Molecular and genetic association of interleukin-6 in tacrine-induced hepatotoxicity. Pharmacogenet Genomics. 2007; 17: 961–972. pmid:18075466
  28. 28. Daly AK, Donaldson PT, Bhatnagar P, Shen Y, Pe’Er I, Floratos A, et al. HLA-B*5701 genotype is a major determinant of drug-induced liver injury due to flucloxacillin. Nat Genet. 2009; 41: 816–819. pmid:19483685
  29. 29. Xia YY, Hu DY, Liu FY, Wang XM, Yuan YL, Tu DH, et al. Design of the anti-tuberculosis drugs induced adverse reactions in China National Tuberculosis Prevention and Control Scheme Study (ADACS). BMC Public Health. 2010; 10: 267. pmid:20492672
  30. 30. Shang P, Xia Y, Liu F, Wang X, Yuan Y, Hu D, et al. Incidence, clinical features and impact on anti-tuberculosis treatment of anti-tuberculosis drug induced liver injury (ATLI) in China. PLoS One. 2011; 6: e21836. pmid:21750735
  31. 31. Lv X, Tang S, Xia Y, Wang X, Yuan Y, Hu D, et al. Adverse reactions due to directly observed treatment strategy therapy in chinese tuberculosis patients: a prospective study. PLoS One. 2013; 8: e65037. pmid:23750225
  32. 32. Xia YY, Hu DY, Liu FY, Wang XM, Yuan YL, Tu DH, et al. Design of the anti-tuberculosis drugs induced adverse reactions in China National Tuberculosis Prevention and Control Scheme Study (ADACS). BMC Public Health. 2010; 10: 267. pmid:20492672
  33. 33. Benichou C. Criteria of drug-induced liver disorders. Report of an international consensus meeting. J Hepatol. 1990; 11: 272–276. pmid:2254635
  34. 34. World Health Organization. The use of the WHO-UMC system for standardized case causality assessment. Uppsala: The Uppsala Monitoring Centre, 2005.
  35. 35. National Tuberculosis Association of the USA. Diagnostic standards and classification of tuberculosis. New York: National Tuberculosis Association, 1961.
  36. 36. Teuber M, Wenz MH, Schreiber S, Franke A. GMFilter and SXTestPlate: software tools for improving the SNPlex genotyping system. BMC Bioinformatics. 2009; 10: 81. pmid:19267942
  37. 37. Xia YY, Zhan SY. Systematic review of anti-tuberculosis drug induced adverse reactions in China. Zhonghua Jie He He Hu Xi Za Zhi. 2007; 30: 419–423. pmid:17673012
  38. 38. Obayashi Y, Arisaka H, Yoshida S, Mori M, Takahashi M. Proline protects liver from D-galactosamine hepatitis by activating the IL-6/STAT3 survival signaling pathway. Amino Acids. 2012; 43: 2371–2380. pmid:22585093
  39. 39. Hong F, Jaruga B, Kim WH, Radaeva S, El-Assal ON, Tian Z, et al. Opposing roles of STAT1 and STAT3 in T cell-mediated hepatitis: regulation by SOCS. J Clin Invest. 2002; 110: 1503–1513. pmid:12438448
  40. 40. Camargo CJ, Madden JF, Gao W, Selvan RS, Clavien PA. Interleukin-6 protects liver against warm ischemia/reperfusion injury and promotes hepatocyte proliferation in the rodent. Hepatology. 1997; 26: 1513–1520. pmid:9397992
  41. 41. James LP, Simpson PM, Farrar HC, Kearns GL, Wasserman GS, Blumer JL, et al. Cytokines and toxicity in acetaminophen overdose. J Clin Pharmacol. 2005; 45: 1165–1171. pmid:16172181
  42. 42. Bollrath J, Greten FR. IKK/NF-kappaB and STAT3 pathways: central signalling hubs in inflammation-mediated tumour promotion and metastasis. EMBO Rep. 2009; 10: 1314–1319. pmid:19893576
  43. 43. Li W, Liang X, Kellendonk C, Poli V, Taub R. STAT3 contributes to the mitogenic response of hepatocytes during liver regeneration. J Biol Chem. 2002; 277: 28411–28417. pmid:12032149
  44. 44. Urban TJ, Shen Y, Stolz A, Chalasani N, Fontana RJ, Rochon J, et al. Limited contribution of common genetic variants to risk for liver injury due to a variety of drugs. Pharmacogenet Genomics. 2012; 22: 784–795. pmid:22968431
  45. 45. Wang H, Lafdil F, Kong X, Gao B. Signal transducer and activator of transcription 3 in liver diseases: a novel therapeutic target. Int J Biol Sci. 2011; 7: 536–550. pmid:21552420
  46. 46. Bajramovic JJ, Bsibsi M, Geutskens SB, Hassankhan R, Verhulst KC, Stege GJ, et al. Differential expression of stress proteins in human adult astrocytes in response to cytokines. J Neuroimmunol. 2000; 106: 14–22. pmid:10814778
  47. 47. Mayer MP, Bukau B. Hsp70 chaperones: cellular functions and molecular mechanism. Cell Mol Life Sci. 2005; 62: 670–684. pmid:15770419
  48. 48. Ucisik-Akkaya E, Davis CF, Gorodezky C, Alaez C, Dorak MT. HLA complex-linked heat shock protein genes and childhood acute lymphoblastic leukemia susceptibility. Cell Stress Chaperones. 2010; 15: 475–485. pmid:20012387
  49. 49. Afzal AR, Mandal K, Nyamweya S, Foteinos G, Poloniecki J, Camm AJ, et al. Association of Met439Thr substitution in heat shock protein 70 gene with postoperative atrial fibrillation and serum HSP70 protein levels. Cardiology. 2008; 110: 45–52. pmid:17934269
  50. 50. Dibonaventura MD, Yuan Y, Lescrauwaet B, L’Italien G, Liu GG, Kamae I, et al. Multicountry Burden of Chronic Hepatitis C Viral Infection among Those Aware of Their Diagnosis: A Patient Survey. PLoS One. 2014; 9: e86070. pmid:24465875