Jiezhun Gu

Acute hepatitis E infection accounts for some cases of suspected drug-induced liver injury.

BACKGROUND & AIMS The diagnosis of drug-induced liver injury relies on exclusion of other causes, including viral hepatitis A, B, and C. Hepatitis E virus (HEV) infection has been proposed as another cause of suspected drug-induced liver disease. We assessed the frequency of HEV infection among patients with drug-induced liver injury in the United States. METHODS The Drug-Induced Liver Injury Network (DILIN) is a prospective study of patients with suspected drug-induced liver injury; clinical information and biological samples are collected to investigate pathogenesis and disease progression. We analyzed serum samples, collected from patients enrolled in DILIN, for immunoglobulin (Ig) G and IgM against HEV; selected samples were tested for HEV RNA. RESULTS Among 318 patients with suspected drug-induced liver injury, 50 (16%) tested positive for anti-HEV IgG and 9 (3%) for anti-HEV IgM. The samples that contained anti-HEV IgM (collected 2 to 24 weeks after onset of symptoms) included 4 that tested positive for HEV RNA genotype 3. Samples from the 6-month follow-up visit were available from 4 patients; they were negative for anti-HEV IgM, but levels of anti-HEV IgG increased with time. Patients who had anti-HEV IgM were mostly older men (89%; mean age, 67 years), and 2 were human immunodeficiency virus positive. Clinical reassessment of the 9 patients with anti-HEV IgM indicated that acute hepatitis E was the most likely diagnosis for 7 and might be the primary diagnosis for 2. CONCLUSIONS HEV infection contributes to a small but important proportion of cases of acute liver injury that are suspected to be drug induced. Serologic testing for HEV infection should be performed, particularly if clinical features are compatible with acute viral hepatitis.

Hepatic histological findings in suspected drug‐induced liver injury: Systematic evaluation and clinical associations

Drug‐induced liver injury (DILI) is considered to be a diagnosis of exclusion. Liver biopsy may contribute to diagnostic accuracy, but the histological features of DILI and their relationship to biochemical parameters and outcomes are not well defined. We have classified the pathological pattern of liver injury and systematically evaluated histological changes in liver biopsies obtained from 249 patients with suspected DILI enrolled in the prospective, observational study conducted by the Drug Induced Liver Injury Network. Histological features were analyzed for their frequency within different clinical phenotypes of liver injury and to identify associations between clinical and laboratory findings and histological features. The most common histological patterns were acute (21%) and chronic hepatitis (14%), acute (9%) and chronic cholestasis (10%), and cholestatic hepatitis (29%). Liver histology from 128 patients presenting with hepatocellular injury had more severe inflammation, necrosis, and apoptosis and more frequently demonstrated lobular disarray, rosette formation, and hemorrhage than those with cholestasis. Conversely, histology of the 73 patients with cholestatic injury more often demonstrated bile plugs and duct paucity. Severe or fatal hepatic injury in 46 patients was associated with higher degrees of necrosis, fibrosis stage, microvesicular steatosis, and ductular reaction among other findings, whereas eosinophils and granulomas were found more often in those with milder injury. Conclusion: We describe an approach for evaluating liver histology in DILI and demonstrate numerous associations between pathological findings and clinical presentations that may serve as a foundation for future studies correlating DILI pathology with its causality and outcome. (Hepatology 2014;59:661–670)

Spectrum of statin hepatotoxicity: Experience of the drug‐induced liver injury network

The HMG‐CoA reductase inhibitors (statins) are widely prescribed for patients with hyperlipidemia and are generally well tolerated. Mild elevations in serum aminotransferases arise in up to 3% of treated patients, but clinically apparent drug‐induced liver injury is rare. The aim of this study is to report the presenting features and outcomes of 22 patients with clinically apparent liver injury due to statins. Among 1,188 cases of drug‐induced liver injury enrolled between 2004 and 2012 in a prospective registry by the U.S. Drug Induced Liver Injury Network, 22 were attributed to a statin. All patients were evaluated in a standard fashion and followed for at least 6 months after onset. The median age was 60 years (range 41‐80), and 15 (68%) were female. The latency to onset of liver injury ranged from 34 days to 10 years (median = 155 days). Median peak levels were alanine aminotransferase 892 U/L, alkaline phosphatase 358 U/L, and total bilirubin 6.1 mg/dL. Nine patients presented with cholestatic hepatitis and 12 patients presented with hepatocellular injury, of which six had an autoimmune phenotype. Nine patients were hospitalized, four developed evidence of hepatic failure, and one died. All commonly used statins were implicated. Four patients developed chronic liver injury, of which three had an autoimmune phenotype of liver injury. Conclusion: Drug‐induced liver injury from statins is rare and characterized by variable patterns of injury, a range of latencies to onset, autoimmune features in some cases, and persistent or chronic injury in 18% of patients, most of whom have an autoimmune phenotype. (Hepatology 2014;60:679–686)

Characteristics of Idiosyncratic Drug-induced Liver Injury in Children: Results From the DILIN Prospective Study

Background: The spectrum and severity of idiosyncratic drug-induced liver injury (DILI) in children are not well established. Patients and Methods: The DILIN (Drug-Induced Liver Injury Network) Prospective Study is a longitudinal multicenter study designed to determine the etiologies, risk factors, and outcomes of suspected DILI. Between September 2004 and September 2009, 30 children ages 2 to 18 years with suspected DILI who met eligibility criteria were enrolled and studied for at least 6 months. Results: Mean age was 14 years; 70% were girls. Antimicrobial (50%) and central nervous system agents (40%) were the most commonly implicated drug classes, with minocycline (4), isoniazid (3), azithromycin (3), atomoxetine (3), and lamotrigine (3) the leading agents. Median time from drug initiation to symptom onset was 32 days. Peak (median) liver chemistries were aspartate aminotransferase 503 U/L, alanine aminotransferase 727 U/L, alkaline phosphatase 331 U/L, and total bilirubin 3.9 mg/dL. Autoantibodies were common (64%). Liver injury pattern was hepatocellular 78%, cholestatic 13%, and mixed 9%. The DILI episode was scored: mild 32%, moderate 44%, severe 20%, and fatal (within 6 months) 4%. Causality assessment was definite 36%, very likely 36%, probable 16%, possible 8%, and unlikely 4%. Seven percent had persistent liver test abnormalities at 6-month follow-up suggesting chronic DILI. Liver biopsies from 12 children most frequently demonstrated chronic hepatitis or bile duct injury. Conclusions: Idiosyncratic DILI in children is most commonly caused by antimicrobial or central nervous system agents and usually presents with a hepatocellular injury pattern. The majority of patients recover, but morbidity and infrequent mortality are seen.

Bayesian bootstrap estimation of ROC curve

Receiver operating characteristic (ROC) curve is widely applied in measuring discriminatory ability of diagnostic or prognostic tests. This makes the ROC analysis one of the most active research areas in medical statistics. Many parametric and semiparametric estimation methods have been proposed for estimating the ROC curve and its functionals. In this paper, we propose the Bayesian bootstrap (BB), a fully nonparametric estimation method, for the ROC curve and its functionals, such as the area under the curve (AUC). The BB method offers a bandwidth-free smoothing approach to the empirical estimate, and gives credible bounds. The accuracy of the estimate of the ROC curve in the simulation studies is examined by the integrated absolute error. In comparison with other existing curve estimation methods, the BB method performs well in terms of accuracy, robustness and simplicity. We also propose a procedure based on the BB approach to test the binormality assumption.

Profiles of serum cytokines in acute drug-induced liver injury and their prognostic significance.

Drug-induced liver injury (DILI) is the most common cause of acute liver failure in the United-States. The aim of the study was to describe serum immune profiles associated with acute DILI, to investigate whether there are profiles associated with clinical features or types of DILI and/or with prognosis, and to assess temporal changes in levels. Twenty-seven immune analytes were measured in the sera of 78 DILI subjects in the Drug-Induced Liver Injury Network (DILIN) and compared with 40 healthy controls. Immune analytes (14 cytokines, 7 chemokines and 6 growth factors) were measured by BioPlex multiplex ELISA at DILI onset and after 6 months. A modeling process utilizing immune principles was used to select a final set of variables among 27 immune analytes and several additional clinical lab values for prediction of early death (within 6 months of DILI onset). Nineteen of the 27 immune analytes were differentially expressed among healthy control, DILI onset and 6-month cohorts. Disparate patterns of immune responses, especially innate and adaptive cellular (mostly TH17) immunity were evident. Low values of four immune analytes (IL-9, IL-17, PDGF-bb and RANTES) and serum albumin are predictive of early death [PPV = 88% (95% CI, 65%-100%), NPV = 97% (95% CI, 93%-100%), accuracy = 96% (95% CI, 92%-100%)]. Conclusions Acute DILI is associated with robust and varying immune responses. High levels of expression of cytokines associated with innate immunity are associated with a poor prognosis, whereas high levels of expression of adaptive cytokines are associated with good long-term prognosis and eventual recovery. Serum immune analyte profiles at DILI onset appear to be of prognostic, and perhaps, diagnostic significance.

Clinical presentations and outcomes of bile duct loss caused by drugs and herbal and dietary supplements

Bile duct loss during the course of drug‐induced liver injury is uncommon, but can be an indication of vanishing bile duct syndrome (VBDS). In this work, we assess the frequency, causes, clinical features, and outcomes of cases of drug‐induced liver injury with histologically proven bile duct loss. All cases of drug‐induced liver injury enrolled into a prospective database over a 10‐year period that had undergone liver biopsies (n = 363) were scored for the presence of bile duct loss and assessed for clinical and laboratory features, causes, and outcomes. Twenty‐six of the 363 patients (7%) with drug‐, herbal‐, or dietary‐supplement–associated liver injury had bile duct loss on liver biopsy, which was moderate to severe (<50% of portal areas with bile ducts) in 14 and mild (50%‐75%) in 12. The presenting clinical features of the 26 cases varied, but the most common clinical pattern was a severe cholestatic hepatitis. The implicated agents included amoxicillin/clavulanate (n = 3), temozolomide (n = 3), various herbal products (n = 3), azithromycin (n = 2), and 15 other medications or dietary supplements. Compared to those without, those with bile duct loss were more likely to develop chronic liver injury (94% vs. 47%), which was usually cholestatic and sometimes severe. Five patients died and 2 others underwent liver transplantation for progressive cholestasis despite treatment with corticosteroids and ursodiol. The most predictive factor of poor outcome was the degree of bile duct loss on liver biopsy. Conclusion: Bile duct loss during acute cholestatic hepatitis is an ominous early indicator of possible VBDS, for which at present there are no known means of prevention or therapy. (Hepatology 2017;65:1267‐1277)

Identification and Characterization of Cefazolin-Induced Liver Injury

BACKGROUND & AIMS Cephalosporin antibiotics are popular because they have a broad spectrum of activity and are generally well tolerated; however, cephalosporin-induced liver injury is considered rare. We describe a new syndrome associated with a single intravenous dose of cefazolin and the clinical features of cephalosporin-induced liver injury. METHODS The Drug-Induced Liver Injury (DILI) Network collected detailed clinical data on 1212 patients with DILI between 2004 and 2012. We analyzed data from 41 patients in whom cephalosporins were implicated as primary agents of liver disease; 33 formally were adjudicated as having cephalosporin-induced DILI. RESULTS Nineteen patients developed clinically apparent DILI after a single intravenous dose of cefazolin. All patients developed self-limited liver injury 3 to 23 days after receiving cefazolin during surgery-often during a minor outpatient procedure. The latency period was 20 days. Clinical features included itching, jaundice, nausea, fever, and rash. Laboratory abnormalities included a mixed or cholestatic pattern of serum enzyme increases. We identified 14 more patients with DILI attributed to other cephalosporins (5 first-generation, 2 second-generation, 6 third-generation, and 1 fourth-generation agent). Although latency and injury patterns were similar for cefazolin and other cephalosporins, the other cephalosporins were associated with more severe courses of injury, including 2 deaths from liver failure. CONCLUSIONS DILI can develop after a single dose of cefazolin. It is characterized by a latency period of 1 to 3 weeks after exposure, a cholestatic biochemical pattern, and a self-limited moderate to severe clinical course. Other cephalosporins can cause a similar but more severe injury.

Azathioprine and 6-Mercaptopurine-induced Liver Injury: Clinical Features and Outcomes.

Objective: The objective of the study was to define the clinical, biochemical, and histologic features of liver injury from thiopurines. Background: Azathioprine (Aza) and 6-mercaptopurine (6-MP) can cause liver injury, but no large series exist. Methods: Clinical and laboratory data and 6-month outcomes of patients with thiopurine hepatotoxicity from the Drug-Induced Liver Injury Network Prospective Study were analyzed. Results: Twenty-two patients were identified, 12 due to Aza and 10 due to 6-MP, with a median age of 55 years; the majority were female (68%). Inflammatory bowel disease was the indication in 55%, and the median thiopurine dose was 150 (range, 25 to 300) mg daily. The median latency to onset was 75 (range, 3 to 2584) days. Injury first arose after a dose escalation in 59% of patients, the median latency after dose increase being 44 (range, 3 to 254) days. At onset, the median alanine aminotransferase level was 210 U/L, alkaline phosphatase was 151 U/L, and bilirubin was 7.4 mg/dL (peak, 13.4 mg/dL). There were no major differences between Aza and 6-MP cases, but anicteric cases typically had nonspecific symptoms and a hepatocellular pattern of enzyme elevations, whereas icteric cases experienced cholestatic hepatitis with modest enzyme elevations in a mixed pattern. One patient with preexisting cirrhosis required liver transplantation; all others resolved clinically. One patient still had moderate alkaline phosphatase elevations 2 years after onset. Conclusions: Nearly three-quarters of patients with thiopurine-induced liver injury present with self-limited, cholestatic hepatitis, typically within 3 months of starting or a dose increase. The prognosis is favorable except in patients with preexisting cirrhosis.

Associations of Gender and a Proxy of female Menopausal status with Histological Features of Drug-Induced Liver Injury

Gender and menopause may contribute to type and severity of drug‐induced liver injury (DILI) by influencing host responses to injury. The aim of this study was to assess the associations of gender and female age 50 [a proxy of menopause] with histological features of liver injury in 212 adults enrolled in the Drug‐Induced Liver Injury Network (DILIN) registry.