Liver Disease and Fibrosis Assessment in Substance Use-Related Disorders

Within subject cross-tissue analyzes of epigenetic clocks in substance use disorder postmortem brain and blood

There is a possible accelerated biological aging in patients with substance use disorders (SUD). The evaluation of epigenetic clocks, which are accurate estimators of biological aging based on DNA methylation changes, has been limited to blood tissue in patients with SUD. Consequently, the impact of biological aging in the brain of individuals with SUD remains unknown. In this study, we evaluated multiple epigenetic clocks (DNAmAge, DNAmAgeHannum, DNAmAgeSkinBlood, DNAmPhenoAge, DNAmGrimAge, and DNAmTL) in individuals with SUD (n = 42), including alcohol (n = 10), opioid (n = 19), and stimulant use disorder (n = 13), and controls (n = 10) in postmortem brain (prefrontal cortex) and blood tissue obtained from the same individuals. We found a higher DNAmPhenoAge (β = 0.191, p-value = 0.0104) and a nominally lower DNAmTL (β = -0.149, p-value = 0.0603) in blood from individuals with SUD compared to controls. SUD subgroup analysis showed a nominally lower brain DNAmTL in subjects with alcohol use disorder, compared to stimulant use disorder and controls (β = 0.0150, p-value = 0.087). Cross-tissue analyzes indicated a lower blood DNAmTL and a higher blood DNAmAge compared to their respective brain values in the SUD group. This study highlights the relevance of tissue specificity in biological aging studies and suggests that peripheral measures of epigenetic clocks in SUD may depend on the specific type of drug used.

Substances use disorders and liver injury: a concise review

Substance use disorders (SUDs) are often associated with alcohol use disorders (AUDs) and psychiatric comorbidities. In addition, they are often subjected to polytherapy. For these reasons SUDs patients are at greater risk of developing liver disease. In this concise review, liver damage from amphetamines, cannabinoids, cocaine and opioids is analyzed and the need to identify a possible associated alcohol use disorder is also suggested. Early identification of liver fibrosis is required in SUDs patients. Fibrosis is the most significant predictor of both prognosis and long-term survival. Its identification helps to promote the abstention from substances and alcohol. Active use of heroin, cocaine and synthetic substances is an absolute controindication for liver transplantation. In cases of remission and adherence to a significant care path, the patient is reevaluated. An addiction specialist should be present within the transplant team. If this is not present, a close collaboration with an addiction unit is mandatory.

Use of cannabis and risk of advanced liver fibrosis in patients with chronic hepatitis C virus infection: A systematic review and meta-analysis

OBJECTIVES

Chronic hepatitis C virus (HCV) infection is one of the most common chronic liver diseases. Several risk factors for the progression of liver fibrosis among these patients have been identified. Use of cannabis could be another risk factor, but the results from epidemiological studies remain inconclusive.

METHODS

Comprehensive literature review was conducted using MEDLINE and EMBASE databases through December 2017 to identify studies that compared the risk of advanced liver fibrosis among HCV-infected patients who use and who do not use cannabis. Effect estimates from each study were extracted and combined together using the random-effect, generic inverse variance method of DerSimonian and Laird.

RESULTS

A total of three cohort studies with 898 participants met the eligibility criteria and were included in the meta-analysis. The risk of advanced liver fibrosis among HCV-infected patients who use cannabis was numerically higher than those who do not use cannabis, although the result did not achieve statistical significance (pooled odds ratio, 1.77; 95% confidence interval, 0.78-4.02). The statistical heterogeneity was high with an I² of 75%.

CONCLUSIONS

This meta-analysis showed that the risk of advanced liver fibrosis among HCV-infected patients who use cannabis was higher than those who do not use cannabis, but the result was not statistically significant. Further studies are required to better characterize the risk.

Drug-Drug Interactions and Diagnostics for Drug Users With HIV and HIV/HCV Coinfections: Introduction

Substance use and pharmacologic treatment of co-occurring infections such as human immunodeficiency virus (HIV) and hepatitis C virus (HCV) are associated with many adverse consequences including pharmacokinetic and pharmacodynamic drug-drug interactions (DDIs). The National Institute on Drug Abuse sponsored a 2-day conference on DDIs at which clinicians/scientists from government, academia, and the pharmaceutical industry presented the most current research findings to formulate a comprehensive overview of DDIs. Specific topics discussed included drug metabolism; drug interactions between medications used in the treatment of HIV, HCV, and substance use disorders; intrahepatic concentrations and methods of assessment of drugs in liver disease of varying etiologies and degrees of impairment; and minimally invasive sampling techniques for the assessment of intrahepatic drug concentrations, viral replication, and changes in gene expression in response to treatment. Finally, the speakers identified research targets and priorities on DDIs. Areas of emphasis included development of diagnostic assays for drug concentration assessment in different organs, an enhanced understanding of factors responsible for alterations in drug metabolism and excretion, and establishment of clinical trials and work groups to study DDIs. Our long-term objective is to broaden investigation in the field of DDIs in substance users.

Assessment of Hepatic Impairment and Implications for Pharmacokinetics of Substance Use Treatment

Although the liver is the primary site of metabolism and biliary excretion for many medications, data are limited on the liver's pharmacokinetic abilities in cirrhosis. Cirrhosis develops through collagen deposition, eventually culminating in end-stage liver disease that compromises hepatic drug metabolism. Consequently, the US Food and Drug Administration (FDA) recommends evaluating the pharmacokinetics of medications in subjects with hepatic impairment if hepatic metabolism constitutes more than 20% of their elimination or if they have a narrow therapeutic range. A variety of noninvasive indices and radiologic procedures can be employed to assess hepatic drug metabolism and excretion. The Child-Pugh score is the most commonly used scale for assessing hepatic impairment among drugs submitted for US FDA approval. The score, originally developed to guide operative mortality in patients undergoing hepatic resection, has not been modified since its inception 5 decades ago. Furthermore, the score was not originally intended to be a guide for potential dose modification in patients with hepatic impairment. These reasons, in combination with the availability of a variety of new imaging modalities and an enhanced understanding of hepatic biology, should foster the development of novel methods to assess the effect of hepatic impairment on liver drug metabolism.