M. Robles-Díaz

Phenotypic characterization of idiosyncratic drug‐induced liver injury: The influence of age and sex

Increased age and female sex are suggested risk factors for drug‐induced hepatotoxicity (DILI). We studied the influence of these variables on the propensity to develop DILI, as well as its clinical expression and outcome. All cases of DILI submitted to the Spanish Registry between April 1994 and August 2007 were analyzed. Six hundred three DILI cases (310 men; mean age, 54 years) showed a similar sex distribution, reaching two peaks in the 40‐ to 49‐year‐old and 60‐ to 69‐year‐old age groups. No cases were recorded in the 20‐ to 29‐year‐old group. Patients aged ≥60 years accounted for 46% of the cases, with a male predominance (158 males, 118 females; P= 0.009), as opposed to younger patients. Older age was independently associated with cholestatic type of injury (odds ratio for an age interval for 1 year: 1.024 [95% confidence interval: 1.010‐1.038]; male/female ratio, 1:2;P = 0.001) and younger age with hepatocellular damage (odds ratio: 0.983 [95% confidence interval: 0.972‐0.994]; female/male ratio, 1:2;P = 0.002). In the mixed group, no age effect was evident. Outcome with fulminant liver failure/liver transplantation was more frequently encountered in women (P < 0.01). Conclusion:Neither older age nor female sex are predisposing factors to overall DILI. However, older age is a determinant for cholestatic damage with a male predominance, whereas younger age is associated with cytolytic damage and a female overrepresentation. Women distinctly exhibit the worst outcome. Knowledge of these phenotypic associations could guide differential diagnosis and attribution of causality in DILI. (HEPATOLOGY 2009;49:2001–2009.)

Hepatotoxicity by Dietary Supplements: A Tabular Listing and Clinical Characteristics

Dietary supplements (DS) are extensively consumed worldwide despite unproven efficacy. The true incidence of DS-induced liver injury (DSILI) is unknown but is probably under-diagnosed due to the general belief of safety of these products. Reported cases of herbals and DS-induced liver injury are increasing worldwide. The aim of this manuscript is to report a tabular listing with a description of DS associated with hepatotoxicity as well as review the phenotype and severity of DSILI. Natural remedies related to hepatotoxicity can be divided into herbal product-induced liver injury and DS-induced liver injury. In this article, we describe different DS associated with liver injury, some of them manufactured DS containing several ingredients (Herbalife™ products, Hydroxycut™, LipoKinetix™, UCP-1 and OxyELITE™) while others have a single ingredient (green tea extract, linoleic acid, usnic acid, 1,3-Dimethylamylamine, vitamin A, Garcinia cambogia and ma huang). Additional DS containing some of the aforementioned ingredients implicated in liver injury are also covered. We have also included illicit androgenic anabolic steroids for bodybuilding in this work, as they are frequently sold under the denomination of DS despite being conventional drugs.

Distinct phenotype of hepatotoxicity associated with illicit use of anabolic androgenic steroids

We have observed an increase in hepatotoxicity (DILI) reporting related to the use of anabolic androgenic steroids (AAS) for bodybuilding.

Definition and risk factors for chronicity following acute idiosyncratic drug-induced liver injury

BACKGROUND & AIMS Chronic outcome following acute idiosyncratic drug-induced liver injury (DILI) is not yet defined. This prospective, long-term follow-up study aimed to analyze time to liver enzyme resolutions to establish the best definition and risk factors of DILI chronicity. METHODS 298 out of 850 patients in the Spanish DILI registry with no pre-existing disease affecting the liver and follow-up to resolution or ⩾1year were analyzed. Chronicity was defined as abnormal liver biochemistry, imaging test or histology one year after DILI recognition. RESULTS Out of 298 patients enrolled 273 (92%) resolved ⩽1year from DILI recognition and 25 patients (8%) were chronic. Independent risk factors for chronicity were older age [OR: 1.06, p=0.011], dyslipidemia [OR: 4.26, p=0.04] and severe DILI [OR: 14.22, p=0.005]. Alanine aminotransferase (ALT), alkaline phosphatase (ALP) and total bilirubin (TB) median values were higher in the chronic group during follow-up. Values of ALP and TB >1.1 x upper limit of normal (xULN) and 2.8 xULN respectively, in the second month from DILI onset, were found to predict chronic DILI (p<0.001). Main drug classes involved in chronicity were statins (24%) and anti-infectives (24%). Histological examination in chronic patients demonstrated two cases with ductal lesion and seven with cirrhosis. CONCLUSIONS One year is the best cut-off point to define chronic DILI or prolonged recovery, with risk factors being older age, dyslipidemia and severity of the acute episode. Statins are distinctly related to chronicity. ALP and TB values in the second month could help predict chronicity or very prolonged recovery. LAY SUMMARY Drug-induced liver injury (DILI) patients who do not resolve their liver damage during the first year should be considered chronic DILI patients. Risk factors for DILI chronicity are older age, dyslipidemia and severity of the acute episode. Chronic DILI is not a very common condition; normally featuring mild liver profile abnormalities and not being an important clinical problem, with the exception of a small number of cases of early onset cirrhosis.

Role of chemical structures and the 1331T>C bile salt export pump polymorphism in idiosyncratic drug-induced liver injury

Several pharmaceutical compounds have been shown to exert inhibitory effects on the bile salt export pump (BSEP) encoded by the ABCB11 gene. We analysed the combined effect on drug‐induced liver injury (DILI) development of the ABCB11 1331T>C polymorphism and the presence of specific chemical moieties, with known BSEP inhibiting properties, in the causative drug.

Biomarkers in DILI: One More Step Forward

Despite being relatively rare, drug-induced liver injury (DILI) is a serious condition, both for the individual patient due to the risk of acute liver failure, and for the drug development industry and regulatory agencies due to associations with drug development attritions, black box warnings, and postmarketing withdrawals. A major limitation in DILI diagnosis and prediction is the current lack of specific biomarkers. Despite refined usage of traditional liver biomarkers in DILI, reliable disease outcome predictions are still difficult to make. These limitations have driven the growing interest in developing new more sensitive and specific DILI biomarkers, which can improve early DILI prediction, diagnosis, and course of action. Several promising DILI biomarker candidates have been discovered to date, including mechanistic-based biomarker candidates such as glutamate dehydrogenase, high-mobility group box 1 protein and keratin-18, which can also provide information on the injury mechanism of different causative agents. Furthermore, microRNAs have received much attention lately as potential non-invasive DILI biomarker candidates, in particular miR-122. Advances in “omics” technologies offer a new approach for biomarker exploration studies. The ability to screen a large number of molecules (e.g., metabolites, proteins, or DNA) simultaneously enables the identification of ‘toxicity signatures,’ which may be used to enhance preclinical safety assessments and disease diagnostics. Omics-based studies can also provide information on the underlying mechanisms of distinct forms of DILI that may further facilitate the identification of early diagnostic biomarkers and safer implementation of personalized medicine. In this review, we summarize recent advances in the area of DILI biomarker studies.

Selected ABCB1, ABCB4 and ABCC2 Polymorphisms Do Not Enhance the Risk of Drug-Induced Hepatotoxicity in a Spanish Cohort

Background and Aims Flawed ABC transporter functions may contribute to increased risk of drug-induced liver injury (DILI). We aimed to analyse the influence of genetic variations in ABC transporters on the risk of DILI development and clinical presentations in a large Spanish DILI cohort. Methods A total of ten polymorphisms in ABCB1 (1236T>C, 2677G>T,A, 3435T>C), ABCB4 (1954A>G) and ABCC2 (−1774G>del, −1549A>G, −24C>T, 1249G>A, 3972C>T and 4544G>A) were genotyped using Taqman 5′ allelic discrimination assays or sequencing in 141 Spanish DILI patients and 161 controls. The influence of specific genotypes, alleles and haplotypes on the risk of DILI development and clinical presentations was analysed. Results None of the individual polymorphisms or haplotypes was found to be associated with DILI development. Carriers homozygous for the ABCC2 −1774del allele were however only found in DILI patients. Hence, this genotype could potentially be associated with increased risk, though its low frequency in our Spanish cohort prevented a final conclusion. Furthermore, carriers homozygous for the ABCC2 −1774G/−1549A/−24T/1249G/3972T/4544G haplotype were found to have a higher propensity for total bilirubin elevations when developing DILI. Conclusions Our findings do not support a role for the analysed polymorphisms in the ABCB1, ABCB4 and ABCC2 transporter genes in DILI development in Spanish patients. The ABCC2 −1774deldel genotype was however restricted to DILI cases and could potentially contribute to enhanced DILI susceptibility.

The value of serum aspartate aminotransferase and gamma‐glutamyl transpetidase as biomarkers in hepatotoxicity

The current definition of the pattern of liver injury in hepatotoxicity (DILI) is given by the R (ratio) value, dividing alanine aminotransferase (ALT) and alkaline phosphatase (ALP) in upper limits of normal at DILI onset. We aimed to explore the validity of using aspartate aminotransferase (AST) and gamma‐glutamyl transpeptidase (GGT) as biomarkers of hepatocelullar and cholestatic damage, respectively, when calculating the R value.

Hepatotoxicity induced by coxibs: how concerned should we be?

ABSTRACT Introduction: The selective inhibitors of COX-2, coxibs, are nonsteroidal anti-inflammatory drugs (NSAIDs) that have much better gastrointestinal safety profile as compared with non-selective NSAIDs. In this review, we analyze both the epidemiological features of coxib-induced hepatotoxicity and the clinical impact of coxib-associated liver damage, based on literature data. Areas covered: We carried out a search of the databases MEDLINE (PubMed), LILACS and SCIELO, from December 1999 to January 2016, to retrieve studies exploring the real impact of coxibs in liver toxicity as compared to non-selective COX-2 inhibitor NSAIDs. Expert opinion: Although reliable data on the incidence of celecoxib- and etoricoxib-induced hepatotoxicity are lacking, because of cohort studies have been generally underpowered to detect hepatic events, coxibs have been scarcely related to hepatotoxicity. Hence, coxib-induced liver injury seems to be an uncommon event, yet exhibits a wide spectrum of damage. Increasing COX-2 drug selectivity, as for rofecoxib, valdecoxib, parecoxib, and lumiracoxib, has been associated with higher cardiovascular risk, as well as dermatological and serious hepatic reactions. The actual risk of liver toxicity from the currently approved coxibs compared with non-selective NSAIDs will be discussed. Finally, classical and novel molecular mechanisms of coxib-induced hepatotoxicity are also described.

Herbal and Dietary Supplement-Induced Liver Injuries in the Spanish DILI Registry

Background & Aims There have been increasing reports of liver injury associated with use of herbal and dietary supplements, likely due to easy access to these products and beliefs among consumers that they are safer or more effective than conventional medications. We aimed to evaluate clinical features and outcomes of patients with herbal and dietary supplement‐induced liver injuries included in the Spanish DILI Registry. Methods We collected and analyzed data on demographic and clinical features, along with biochemical parameters, of 32 patients with herbal and dietary supplement‐associated liver injury reported to the Spanish DILI registry from 1994 through 2016. We used analysis of variance to compare these data with those from cases of liver injury induced by conventional drugs or anabolic androgenic steroid‐containing products. Results Herbal and dietary supplements were responsible for 4% (32 cases) of the 856 DILI cases in the registry; 20 cases of DILI (2%) were caused by anabolic androgenic steroids. Patients with herbal and dietary supplement‐induced liver injury were a mean age of 48 years and 63% were female; they presented a mean level of alanine aminotransferase 37‐fold the upper limit of normal, 28% had hypersensitivity features, and 78% had jaundice. Herbal and dietary supplement‐induced liver injury progressed to acute liver failure in 6% of patients, compared with none of the cases of anabolic androgenic steroid‐induced injury and 4% of cases of conventional drugs. Liver injury after repeat exposure to the same product that caused the first DILI episode occurred in 9% of patients with herbal and dietary supplement‐induced liver injury vs none of the patients with anabolic androgenic steroid‐induced injury and 6% of patients with liver injury from conventional drugs. Conclusion In an analysis of cases of herbal and dietary supplement‐induced liver injury in Spain, we found cases to be more frequent among young women than older patients or men, and to associate with hepatocellular injury and high levels of transaminases. Herbal and dietary supplement‐induced liver injury is more severe than other types of DILI and re‐exposure is more likely. Increasing awareness of the hepatoxic effects of herbal and dietary supplements could help physicians make earlier diagnoses and reduce the risk of serious liver damage.