Raúl J. Andrade

Case Definition and Phenotype Standardization in Drug-Induced Liver Injury

Drug‐induced liver injury (DILI) is the most frequent reason cited for the withdrawal of approved drugs from the market and accounts for up to 15% of the cases of acute liver failure. Investigators around the globe have begun to identify and study patients with DILI; several large registries and tissue banks are being established. In order to gain the maximum scientific benefit from these efforts, the definitions and terminology related to the clinical phenotypes of DILI must be harmonized. For this purpose, an international DILI Expert Working Group of clinicians and scientists reviewed current DILI terminology and diagnostic criteria so as to develop more uniform criteria that would define and characterize the spectrum of clinical syndromes that constitute DILI. Consensus was established with respect to the threshold criteria for definition of a case as being DILI, the pattern of liver injury, causality assessment, severity, and chronicity. Consensus was also reached on approaches to characterizing DILI in the setting of chronic liver diseases, including autoimmune hepatitis (AIH).

Susceptibility to Amoxicillin-Clavulanate-Induced Liver Injury is Influenced by Multiple HLA Class I and II Alleles

BACKGROUND & AIMS Drug-induced liver injury (DILI), especially from antimicrobial agents, is an important cause of serious liver disease. Amoxicillin-clavulanate (AC) is a leading cause of idiosyncratic DILI, but little is understood about genetic susceptibility to this adverse reaction. METHODS We performed a genome-wide association study using 822,927 single nucleotide polymorphism (SNP) markers from 201 White European and US cases of DILI following AC administration (AC-DILI) and 532 population controls, matched for genetic background. RESULTS AC-DILI was associated with many loci in the major histocompatibility complex. The strongest effect was with an HLA class II SNP (rs9274407, P=4.8×10(-14)), which correlated with rs3135388, a tag SNP of HLA-DRB1*1501-DQB1*0602 that was previously associated with AC-DILI. Conditioned on rs3135388, rs9274407 is still significant (P=1.1×10(-4)). An independent association was observed in the class I region (rs2523822, P=1.8×10(-10)), related to HLA-A*0201. The most significant class I and II SNPs showed statistical interaction (P=.0015). High-resolution HLA genotyping (177 cases and 219 controls) confirmed associations of HLA-A*0201 (P=2×10(-6)) and HLA-DQB1*0602 (P=5×10(-10)) and their interaction (P=.005). Additional, population-dependent effects were observed in HLA alleles with nominal significance. In an analysis of autoimmune-related genes, rs2476601 in the gene PTPN22 was associated (P=1.3×10(-4)). CONCLUSIONS Class I and II HLA genotypes affect susceptibility to AC-DILI, indicating the importance of the adaptive immune response in pathogenesis. The HLA genotypes identified will be useful in studies of the pathogenesis of AC-DILI but have limited utility as predictive or diagnostic biomarkers because of the low positive predictive values.

HIV coinfection shortens the survival of patients with hepatitis C virus-related decompensated cirrhosis.

The impact of human immunodeficiency virus (HIV) coinfection on the survival of patients with hepatitis C virus (HCV)‐related end‐stage liver disease (ESLD) is unknown. Because HIV infection is no longer considered an absolute contraindication for liver transplantation in some countries, it has become a priority to address this topic. The objective of this study was to compare the survival of HIV‐infected and HIV‐uninfected patients with decompensated cirrhosis due to HCV. In a retrospective cohort study, the survival of 1,037 HCV monoinfected and 180 HCV/HIV‐coinfected patients with cirrhosis after the first hepatic decompensation was analyzed. Of the group, 386 (37%) HCV‐monoinfected and 100 (56%) HCV/HIV‐coinfected subjects died during the follow‐up. The median survival time of HIV‐infected and HIV‐uninfected patients was 16 and 48 months, respectively (P < .001). The relative risk (95% CI) of death for HIV‐infected patients was 2.26 (1.51‐3.38). Other independent predictors of survival were age older than 63 years (2.25 [1.53‐3.31]); Child‐Turcotte‐Pugh class B versus class A (1.95 [1.41–2.68]) and class C versus class A (2.78 [1.66–4.70]); hepatitis D virus infection (1.56 [1.12–4.77]); model for end‐stage liver disease score, (1.05 [1.01‐1‐11]); more than one simultaneous decompensation (1.23 [1.12–3.33]); and the type of the first hepatic decompensation, with a poorer prognosis associated with encephalopathy compared with portal hypertensive gastrointestinal bleeding (2.03 [1.26–3.10]). In conclusion, HIV coinfection reduces considerably the survival of patients with HCV‐related ESLD independently of other markers of poor prognosis. This fact must be taken into account to establish the adequate timing of liver transplantation in HIV‐coinfected subjects. (HEPATOLOGY 2005.)

Outcome of acute idiosyncratic drug‐induced liver injury: Long‐term follow‐up in a hepatotoxicity registry

A chronic adverse reaction may occur in some instances of drug‐induced liver injury (DILI), even despite drug cessation. In our study, we obtained records from a Spanish registry and evaluated cases of DILI with biochemical evidence of long‐term damage. Chronic outcome was defined as a persistent biochemical abnormality of hepatocellular pattern of damage more than 3 months after drug withdrawal or more than 6 months after cholestatic/mixed damage. Data on 28 patients with a chronic clinical evolution (mean follow‐up 20 months) between November 1995 and October 2005 were retrieved (18 female; overall mean age 55 yr) and accounted for 5.7% of total idiosyncratic DILI cases (n = 493) submitted to the registry. The main drug classes were cardiovascular and central nervous system (28.5% and 25%, respectively), which, in contrast, represented only 9.8% and 13%, respectively, of all DILI cases. The most frequent causative drugs were amoxicillin–clavulanate (4 of 69 cases), bentazepam (3 of 7 cases), atorvastatin (2 of 7 cases), and captopril (2 of 5 cases). Patients with cholestatic/mixed injury (18 of 194 cases [9%]) were more prone to chronicity than patients with hepatocellular injury (10 of 240 cases; P < .031). In the case of chronic hepatocellular injury, 3 patients progressed to cirrhosis and 2 to chronic hepatitis. In the cholestatic/mixed group, liver biopsy indicated cirrhosis in 1 patient and ductal lesions in 3 patients. In conclusion, cholestatic/mixed type of damage is more prone to become chronic while, in the hepatocellular pattern, the severity is greater. Cardiovascular and central nervous system drugs are the main groups leading to chronic liver damage. (HEPATOLOGY 2006;44:1581–1588.)

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.)

Standardization of Nomenclature and Causality Assessment in Drug-Induced Liver Injury: Summary of a Clinical Research Workshop

Idiosyncratic drug‐induced liver injury (DILI) is an important but relatively infrequent cause of potentially severe acute and chronic liver injury. The aim of this clinical research workshop was to review and attempt to standardize the current nomenclature and terminology used in DILI research. Because DILI is a diagnosis of exclusion, selected elements of the medical history, laboratory tests, and previous reports were proposed to improve causality assessment. Definitions and diagnostic criteria regarding the onset of DILI, evolution of liver injury, risk factors, and mandatory testing versus optional testing for competing causes were reviewed. In addition, the role of intentional and inadvertent rechallenge, liver histology, and host genetic polymorphisms in establishing the diagnosis and prognosis of DILI were reviewed. Consensus was established regarding the need to develop a web‐of‐knowledge database that provides concise, reliable, and updated information on cases of liver injury due to drugs and herbal and dietary supplements. In addition, the need to develop drug‐specific computerized causality assessment methods that are derived from prospectively phenotyped cases was a high priority. Proposed scales for grading DILI severity and assessing the likelihood of an agent causing DILI and written criteria for improving the reliability, accuracy, and reproducibility of expert opinion were reviewed. Finally, the unique challenges of assessing causality in children, patients with underlying liver disease, and subjects taking herbal and dietary supplements were discussed. Conclusion: Workshop participants concluded that multicenter referral networks enrolling patients with suspected DILI according to standardized methodologies are needed. These networks should also collect biological samples that may provide crucial insights into the mechanism(s) of DILI with the ultimate aim of preventing future cases of DILI. (HEPATOLOGY 2010)

The use of liver biopsy evaluation in discrimination of idiopathic autoimmune hepatitis versus drug-induced liver injury.

Distinguishing drug‐induced liver injury (DILI) from idiopathic autoimmune hepatitis (AIH) can be challenging. We performed a standardized histologic evaluation to explore potential hallmarks to differentiate AIH versus DILI. Biopsies from patients with clinically well‐characterized DILI [n = 35, including 19 hepatocellular injury (HC) and 16 cholestatic/mixed injury (CS)] and AIH (n = 28) were evaluated for Ishak scores, prominent inflammatory cell types in portal and intra‐acinar areas, the presence or absence of emperipolesis, rosette formation, and cholestasis in a blinded fashion by four experienced hepatopathologists. Histologic diagnosis was concordant with clinical diagnosis in 65% of cases; but agreement on final diagnosis among the four pathologists was complete in only 46% of cases. Interface hepatitis, focal necrosis, and portal inflammation were present in all evaluated cases, but were more severe in AIH (P < 0.05) than DILI (HC). Portal and intra‐acinar plasma cells, rosette formation, and emperiopolesis were features that favored AIH (P < 0.02). A model combining portal inflammation, portal plasma cells, intra‐acinar lymphocytes and eosinophils, rosette formation, and canalicular cholestasis yielded an area under the receiver operating characteristic curve (AUROC) of 0.90 in predicting DILI (HC) versus AIH. All Ishak inflammation scores were more severe in AIH than DILI (CS) (P ≤ 0.05). The four AIH‐favoring features listed above were consistently more prevalent in AIH, whereas portal neutrophils and intracellular (hepatocellular) cholestasis were more prevalent in DILI (CS) (P < 0.02). The combination of portal inflammation, fibrosis, portal neutrophils and plasma cells, and intracellular (hepatocellular) cholestasis yielded an AUC of 0.91 in predicting DILI (CS) versus AIH. Conclusion: Although an overlap of histologic findings exists for AIH and DILI, sufficient differences exist so that pathologists can use the pattern of injury to suggest the correct diagnosis. (Hepatology 2011;)

Glutathione S-transferase m1 and t1 null genotypes increase susceptibility to idiosyncratic drug-induced liver injury.

Individual vulnerability to drug‐induced liver injury (DILI) might result from deficiencies in the detoxification process, which determines the level of exposure to the reactive metabolite. We evaluated whether a genetically determined reduction in the ability to detoxify electrophilic compounds, such as that expected among individuals with glutathione S‐transferase (GST) null genotypes, might play a role in determining the risk for DILI and its clinical expression. Genomic DNA from 154 patients (74 men, 80 women; mean age, 53 years) with a diagnosis of DILI as assessed with the Council for International Organizations of Medical Science scale and 250 sex‐ and age‐matched healthy controls were analyzed. A multiplex polymerase chain reaction–based method was used to detect GSTM1 and GSTT1 gene deletions. Carriers of double GSTT1‐M1 null genotypes had a 2.70‐fold increased risk of developing DILI compared with noncarriers (odds ratio 2.70, 95% confidence interval 1.45‐5.03; P = 0.003). The odds ratio for DILI patients receiving antibacterials, and NSAIDs were 3.52 (P = 0.002), and 5.61 (P = 0.001), respectively. Patients with amoxicillin‐clavulanate hepatotoxicity (n = 32) had a 2.81‐fold increased risk (P = 0.037). Patients classified by the combined GSTT1 and GSTM1 null genotypes did not differ with regard to the type of injury, clinical presentation, or outcome, except for the predominance of women in the combined null genotype (P < 0.001). Conclusion: The double‐null genotype for GSTT1 and GSTM1 might play a role in determining the susceptibility to develop DILI, as a general mechanism that occurs regardless of the type of drug involved, and predominantly in women. (HEPATOLOGY 2008;48:588–596.)

Effect of sustained virological response to treatment on the incidence of abnormal glucose values in chronic hepatitis C

BACKGROUND/AIMS To investigate the effect of sustained virological response (SVR) on impaired fasting glucose (IFG) and/or type 2 diabetes (T2DM); to assess the influence of glucose abnormalities on the SVR rate. METHODS 1059 patients with chronic HCV; normal glucose (< 100 mg/dl) in 734, IFG (between 100 and 125 mg/dl) in 218, and T2DM (126 mg/dl) in 107 cases, were treated with interferon plus ribavirin over 24 or 48 weeks, depending on viral genotype. RESULTS The SVR rate was lower in patients with IFG and/or T2DM than in patients with normal glucose concentrations [143/325 (44%) vs. 432/734 (58.8%); P=0.002]. In the follow-up, abnormal glucose concentrations were observed in 74 of 304 (24.3%) non-responders and in 49 of 430 (11.4%) sustained responders (log-rank: 13.8; P=0.00002). Reverse stepwise logistic regression analysis identified the independent variables predictive of IFG or T2DM development as: sustained response (OR: 0.44; 95%CI=0.20-0.97; P=0.004) and fibrosis stage (OR: 1.46; 95%CI=1.06-2.01;P=0.02). Family history of DM, steatosis, gender, HCV viral load, genotype, triglycerides, cholesterol and BMI did not enter the multivariate analysis equation. CONCLUSIONS SVR reduces the risk of IFG and/or T2DM development in patients with chronic hepatitis C while altered glucose metabolism impairs sustained response to viral treatment.

Treatment of insulin resistance with metformin in naïve genotype 1 chronic hepatitis C patients receiving peginterferon alfa‐2a plus ribavirin

Insulin resistance affects sustained virological response (SVR) in chronic hepatitis C. To know whether adding metformin to standard antiviral treatment improves SVR, we conducted a prospective, multicentered, randomized, double‐blinded, placebo‐controlled trial in 19 Spanish hospitals, including 123 consecutive patients with genotype 1 chronic hepatitis C and insulin resistance. Patients were randomized to receive either metformin (arm A; n = 59) or placebo (arm B; n = 64) in addition to peginterferon alfa‐2a (180 μg/week) and ribavirin (1000–1200 mg/day). The primary end point was SVR, and secondary endpoints were viral clearance at weeks 12, 24, and 48, and changes in the homeostasis model assessment (HOMA) index over the first 24 weeks. There were no differences between arms at baseline. In the intent‐to‐treat analysis, SVR was observed in 53% versus 42% in arm A and arm B, respectively (P = NS). In the subgroup analyses, SVR was higher in females (n = 54) receiving metformin: arm A, 58% (15/26) versus 29% (8/28) arm B (P = 0.03). In the per protocol analysis (PPA; n = 101), SVR was 67% in arm A and 49% in arm B (P = 0.06). Viral decline during the first 12 weeks was greater in females receiving metformin: −4.88 (1.18) versus −4.0 (1.44) (P = 0.021), whereas no differences were seen in males. The triple therapy was well tolerated, but diarrhea was more often seen in arm A (34% versus 11%; P < 0.05). Conclusion: Adding metformin to peginterferon and ribavirin was safe and improved insulin sensitivity. Although the study failed to show a statistically significant difference between arms, it did show an improved SVR in females. (HEPATOLOGY 2009.)