Do genetic polymorphisms of B-cell CLL/lymphoma 2 confer susceptibility to anti-tuberculous therapy-associated drug-induced liver injury?

OBJECTIVES

The aim of this study was to identify the relationship between B-cell CLL/lymphoma 2 (BCL2) polymorphisms and susceptibility to anti-tuberculous therapy-associated drug-induced liver injury (ATT-DILI).

METHODS

A total of 746 tuberculosis (TB) patients were enrolled in this study. Twenty-one selected single nucleotide polymorphisms in BCL2 were analyzed by custom-by-design 2×48-Plex SNPscan kit. The allele and genotype frequencies between patients with and without ATT-DILI were compared using three different genetic models.

RESULTS

A total of 727/746 participants were successfully genotyped, and 112 of them were diagnosed with ATT-DILI. The A allele of rs8085707, G allele of rs76986960, and A allele of rs949037 conferred an increased risk of ATT-DILI, with estimated odd ratios (ORs) of 2.181 (95% confidence interval (CI) 1.345-3.536, p=0.001), 1.983 (95% CI 1.060-3.709, p=0.029), and 1.390 (95% CI 1.032-1.873, p=0.03), respectively. Bonferroni correction indicated that the A allele of rs8085707 was a risk factor for ATT-DILI (Bonferroni correction: p=0.026). The additive model suggested that patients with the AA genotype of rs8085707 had a significantly higher risk of ATT-DILI compared with those with the GG genotype (Bonferroni correction: p=0.036). The influence of BCL2 polymorphisms on clinical characteristics (clinical symptoms, disease subtypes, and laboratory indicators) was also identified.

CONCLUSIONS

This study is novel in suggesting an association between BCL2 polymorphisms and the risk of ATT-DILI.

The Latin American DILI Registry Experience: A Successful Ongoing Collaborative Strategic Initiative

Drug induced liver injury (DILI) is a rare but well recognized serious adverse reaction. Pre-marketing studies may not detect liver injury, and DILI becomes very often apparent after the drug is launched to the market. Specific biomarkers for DILI prediction or diagnosis are not available. Toxic liver reactions present with a wide spectrum of phenotypes and severity, and our knowledge on the mechanisms underlying idiosyncratic reactions and individual susceptibility is still limited. To overcome these limitations, country-based registries and multicenter research networks have been created in Europe and North America. Reliable epidemiological data on DILI in Latin America (LA), a region with a large variety of ethnic groups, were however lacking. Fortunately, a LA network of DILI was set up in 2011, with the support of the Spanish DILI Registry from the University of Malaga. The primary aim of the Latin DILI Network (LATINDILIN) Registry was to prospectively identify bona fide DILI cases and to collect biological samples to study genetic biomarkers. Physicians involved in the project must complete a structured report form describing the DILI case presentation and follow-up which is submitted to a Coordinator Center in each country, where it is further assessed for completeness. During the last four years, several LA countries (Argentina, Uruguay, Chile, Mexico, Paraguay, Brazil, Ecuador, Peru, Venezuela and Colombia) have joined the network and committed with this project. At that point, to identify both our strengths and weaknesses was a very important issue. In this review, we will describe how the LATINDILI Registry was created. The aims and methods to achieve these objectives will be discussed in depth. Additionally, both the difficulties we have faced and the strategies to solve them will be also pinpointed. Finally, we will report on our preliminary results, and discuss ideas to expand and to keep running this network.

Translational biomarkers of acetaminophen-induced acute liver injury

Acetaminophen (APAP) is a commonly used analgesic drug that can cause liver injury, liver necrosis and liver failure. APAP-induced liver injury is associated with glutathione depletion, the formation of APAP protein adducts, the generation of reactive oxygen and nitrogen species and mitochondrial injury. The systems biology omics technologies (transcriptomics, proteomics and metabolomics) have been used to discover potential translational biomarkers of liver injury. The following review provides a summary of the systems biology discovery process, analytical validation of biomarkers and translation of omics biomarkers from the nonclinical to clinical setting in APAP-induced liver injury.

Characteristics and clinical outcome of nonsteroidal anti-inflammatory drug-induced acute hepato-nephrotoxicity among Chinese patients

AIM: To determine the clinicopathological characteristics of nonsteroidal anti-inflammatory drug (NSAID)-induced acute hepato-nephrotoxicity among Chinese patients.

METHODS: We conducted a retrospective chart review of patients using the International Classification of Diseases, Ninth Revision diagnosis code for acute kidney injury (AKI) (584.5 or 584.9) and for acute liver injury (ALI) (570.0 or 573.3) from January 2004 to December 2013. Medical records were reviewed to confirm the diagnosis of AKI and ALI and to quantify NSAID administration.

RESULTS: Seven of 59 patients (11.8%) were identified with acute hepato-nephrotoxicity induced by NSAIDs. Five patients (71.4%) received over the recommended NSAIDs dose. Compared with NSAIDs-associated mere AKI, the risk factors of NSAIDs-induced acute hepato-nephrotoxicity are age older than 60 years (57.1%), a high prevalence of alcohol use (71.4%) and positive hepatitis B virus (HBV) markers (85.7%). Compared with NSAIDs-associated mere ALI, the risk factors of NSAIDs-induced acute hepato-nephrotoxicity are age older than 60 years (57.1%), increased extracellular volume depletion (71.4%), and renin-angiotensin-aldosterone system (RAAS) inhibitor combined use (57.1%). Acute interstitial nephritis and acute tubulointerstitial disease were apparent in three out of six (42.9%) kidney biopsy patients, respectively. Acute hepatitis was found in four out of six (66.7%) liver biopsy patients. Overall complete recovery occurred in four patients within a mean of 118.25 ± 55.42 d.

CONCLUSION: The injury typically occurred after an overdose of NSAIDs. The risk factors include age older than 60 years, alcohol use, positive HBV markers, extracellular volume depletion and RAAS inhibitor combined use.

Kava hepatotoxicity: pathogenetic aspects and prospective considerations

Kava hepatotoxicity is a well-defined herb-induced liver injury, caused by the use of commercial anxyolytic ethanolic and acetonic kava extracts, and of traditional recreational aqueous kava extracts. The aim of this review is to elucidate possible pathogenetic factors for the development of kava-induced liver injury, considering also confounding variables. In patients with liver disease in a causal relation to kava ± comedication, confounding factors include non-adherence to therapy recommendations and comedication consisting of synthetic and herbal drugs and dietary supplements including herbal ones and herbs-kava mixtures. Various possible pathogenetic factors have to be discussed and comprise metabolic interactions with exogenous compounds at the hepatic microsomal cytochrome P450 level; genetic enzyme deficiencies; toxic constituents and metabolites derived from the kava extract including impurities and adulterations; cyclooxygenase inhibition; P-glycoprotein alterations; hepatic glutathione depletion; solvents and solubilizers of the extracts; and kava raw material of poor quality. In particular, inappropriate kava plant parts and unsuitable kava cultivars may have been used sometimes for manufacturing the kava extracts instead of the rhizome of a noble cultivar of the kava plant (Piper methysticum G. Forster). In conclusion, kava hepatotoxicity occurred independently of the extraction medium used for the kava extracts and may primarily be attributed to daily overdose, prolonged treatment and to a few kava extract batches of poor quality; by improving kava quality and adherence to therapy recommendation under avoidance of comedication, liver injury by kava should be a preventable disease, at least to a major extent.

Isoniazid hepatotoxicity associated with treatment of latent tuberculosis infection: a 7-year evaluation from a public health tuberculosis clinic

OBJECTIVES

To determine the overall incidence of isoniazid (INH) hepatotoxicity in a public health tuberculosis clinic over a 7-year period, and to determine if systematic, limited aspartate aminotransferase (AST) monitoring would be of benefit in detecting INH hepatotoxicity.

METHODS

Evaluation of INH hepatotoxicity in adults aged > or = 25 years from a database maintained from fall 1996 to 2003 in a public health department clinic. Hepatotoxicity was defined as AST levels more than five times the upper limit of normal (ULN).

RESULTS

Among 3,377 patients started on INH therapy, 19 patients had AST levels more than five times the ULN, or a rate of 5.6 per 1,000 patients. Only 1 of 19 patients had prodromal symptoms associated with hepatotoxicity. After 1 month, 3 months, and 6 months of therapy, the numbers of hepatotoxic events per 1,000 patients were 2.75, 7.20, and 4.10. The age-specific numbers of hepatotoxic events per 1,000 patients were 4.40 for those from 25 to 34 years of age, inclusive; 8.54 for those between 35 to 49 years of age, inclusive; and 20.83 for those > or = 50 years old. Age > 49 years (p < 0.02) and baseline AST greater than ULN (p < 0.0003) were risk factors for hepatotoxicity.

CONCLUSIONS

Consistent with earlier trials, INH hepatoxicity is age related. Our results suggest hepatotoxicity is also related to baseline AST greater than ULN. Moderate-to-severe hepatotoxicity frequently occurs without symptoms, suggesting the value of more widespread AST monitoring.

Tuberculosis prevention in Mexican immigrants: limitations of short-course therapy

BACKGROUND

Two months of rifampin and pyrazinamide (RIF/PZA) for tuberculosis prevention has been advocated as a way to improve adherence in mobile populations, such as recent immigrants. However, RIF/PZA requires intensive patient and laboratory monitoring for hepatotoxicity.

OBJECTIVES

To describe the feasibility and outcomes of using RIF/PZA for TB prevention during a tuberculosis outbreak in a Mexican immigrant community, where 23 adults and 11 children were treated with RIF/PZA between August 2001 and October 2001.

METHODS

Retrospective chart review and interviews with health department employees were conducted to assess completion rates, hepatotoxicity, cost, and feasibility of monitoring.

RESULTS

Ten (91%) children and 13 (57%) adults completed RIF/PZA. One child (9%) and four adults (17%) developed drug-induced hepatitis. Cultural barriers affected care. The adults resisted the biweekly blood draw, believing it would "drain them of energy." RIF/PZA, plus monitoring, was twice as costly as 4 months of rifampin.

CONCLUSIONS

RIF/PZA was associated with significant hepatotoxicity, poor completion, and cultural barriers to monitoring, and was more costly than standard therapy. Tuberculosis prevention must address potential clinical, cultural, and economic barriers to completion and monitoring of short-course therapy in immigrants.

Frequency and type of reactions to antituberculosis drugs: observations in routine treatment

SETTING

United Kingdom, 1978-1992.

OBJECTIVE

To assess the incidence and type of reactions to antituberculosis drugs in an unselected series of patients.

DESIGN

All patients treated for tuberculosis had details of drug treatment, durations and side-effects requiring alteration of treatment available. The data was compiled retrospectively for 1978-1980 patients and prospectively thereafter. Analysis of drug reactions was by drug, total months drug use, by age, sex and ethnic group, and reaction type.

RESULTS

Of 1317 patients 67 (5.1%) had 70 reactions to antituberculosis drugs requiring modification of treatment. The frequency of drug reactions increased from 2.3% at age 0-19 to 4.6% at age 20-39, 7.1% for age 40-59 and to 8.4% for those aged 60 and over. Females had significantly higher reactions rates than males. White patients had higher reaction rates than Pakistani and Indian patients, mainly due to the average age being greater.

CONCLUSION

The drug reaction rate of 5.1% in this largely prospective study is lower than that reported in other unselected series in the UK and other countries.