Drug-Induced Liver Injury After Liver Transplantation

Algorithmic Approach to Deranged Liver Functions After Transplantation

Liver transplant (LT) recipients require close follow-up with regular monitoring of the liver function tests (LFTs). Evaluation of deranged LFT should be individualized depending upon the time since LT, peri-operative events, clinical course, and any complications. These derangements can range from mild and asymptomatic to severe and symptomatic elevations requiring expedited personalized assessment and management. Pattern of LFT derangement (hepatocellular, cholestatic, or mixed), donor-recipient risk factors, timing after LT (post-operative, 1-12 months, and >12 months since LT) along with clinical context and symptomatology are important considerations before proceeding with the initial evaluation. Compliance to immunosuppression and drug interactions should be ascertained along with local epidemiology of infections. Essential initial evaluation must include an ultrasound abdomen with Doppler to rule out any structural causes such as biliary or vascular complications apart from focussed laboratory evaluation. Early allograft dysfunction, ischemia reperfusion injury, small-for-size syndrome, biliary leaks, hepatic artery, and portal vein thrombosis are usual culprits in the early post-operative period whereas viral hepatitis (acute or reactivation), opportunistic infections, and recurrence of the primary disease are more frequent in the later period. Graft rejection, biliary strictures, sepsis, and drug induced liver injury remain possible etiologies at all times points after LT. Initial evaluation algorithm must be customized based on history, clinical examination, risk factors, and pattern and severity of deranged LFT. Allograft rejection is a diagnosis of exclusion and requires liver biopsy to confirm and assess severity. Empirical treatment of rejection sans liver biopsy is discouraged.

Asian Pacific Association for the Study of the Liver clinical practice guidelines on liver transplantation

Liver transplantation is a highly complex and challenging field of clinical practice. Although it was originally developed in western countries, it has been further advanced in Asian countries through the use of living donor liver transplantation. This method of transplantation is the only available option in many countries in the Asia-Pacific region due to the lack of deceased organ donation. As a result of this clinical situation, there is a growing need for guidelines that are specific to the Asia-Pacific region. These guidelines provide comprehensive recommendations for evidence-based management throughout the entire process of liver transplantation, covering both deceased and living donor liver transplantation. In addition, the development of these guidelines has been a collaborative effort between medical professionals from various countries in the region. This has allowed for the inclusion of diverse perspectives and experiences, leading to a more comprehensive and effective set of guidelines.

Risk of adverse outcomes following treatment with direct acting antiviral drugs in HCV infected patients with liver cirrhosis

Introduction

Hepatitis C virus (HCV) is the second major cause of death in Pakistan. Previously, interferon-based regimens were considered highly recommended therapy for HCV patients. Since 2015, interferon-based therapy has been replaced with interferon-free therapy also known as Direct Acting Antiviral (DAA) drugs. The treatment response of interferon-free regimens has been reported as highly effective treatment option with more than 90% sustained virological response (SVR) in chronic HCV infected patients in western countries of the world.

Objective

This study aims to analyze the treatment response of DAA drugs in HCV-infected Pakistani population with liver cirrhosis.

Methodology

We collected the total 94 sample of the HCV infected patients, from June 2020 to September 2020. Forty-six (46) patients were cirrhotic, and forty-eight (48) patients were non-cirrhotic. Data was analyzed using IBM SPSS version 21 software.

Conclusion

The findings of our study suggest that the response rate was 82.60% in HCV cirrhotic patients and 68.75% in HCV non-cirrhotic patients. Our study showed that overall treatment response was independent of age and gender. We also observed some adverse effects such as hepatocellular carcinoma, portosystemic encephalopathy (PSE), spontaneous bacterial peritonitis (SBP), hepatorenal syndrome (HRS), upper gastrointestinal bleeding (UGIB), ascites, among patients following treatment with interferon-free regimens.

Pharmacokinetic and pharmacodynamic considerations of antibiotics and antifungals in liver transplantation recipients

The liver plays a major role in drug metabolism. Liver transplantation impacts the intrinsic metabolic capability and extrahepatic mechanisms of drug disposition and elimination. Different levels of inflammation and oxidative stress during transplantation, the process of liver regeneration, and the characteristics of the graft alter the amount of functional hepatocytes and activity of liver enzymes. Binding of drugs to plasma proteins is affected by the hyperbilirubinemia status and abnormal synthesis of albumin and alpha-1-acid glycoproteins. Postoperative intensive care complications such as biliary, circulatory, and cardiac also impact drug distribution. Renally eliminated antimicrobials commonly present reduced clearance due to hepatorenal syndrome and the use of nephrotoxic immunosuppressants. In addition, liver transplantation recipients are particularly susceptible to multidrug-resistant infections due to frequent manipulation, multiple hospitalizations, invasive devices, and frequent use of empiric broad-spectrum therapy. The selection of appropriate anti-infective therapy must consider the pathophysiological changes after transplantation that impact the pharmacokinetics and pharmacodynamics of antibiotics and antifungal drugs.

Present and future management of viral hepatitis

Viral hepatitis can result in important morbidity and mortality, with its impact on health conditioned by the specific type of hepatitis, the geographical region of presentation and the development and access to new drugs, among other factors. Most acute presentation forms are self-limiting and may even go unnoticed, with just a small percentage of cases leading to acute liver failure that may necessitate transplantation or even cause the death of the patient. However, when they become chronic, as in the case of hepatitis B virus and C virus, unless they are diagnosed and treated adequately they may have severe consequences, like cirrhosis or hepatocarcinoma. Understanding of the mechanisms of transmission, the pathogenesis, the presence of vaccinations and the development over recent years of new highly-efficient, potent drugs have meant that we are now faced with a new scenario in the management of viral hepatitis, particularly hepatitis B virus and hepatitis C virus. The spectacular advances in hepatitis C virus treatment have led the World Health Organization to propose the objective of its eradication by 2030. The key aspect to achieving this goal is to ensure that these treatments reach all the more vulnerable population groups, in whom the different types of viral hepatitis have a high prevalence and constitute a niche that may perpetuate infection and hinder its eradication. Accordingly, micro-elimination programs assume special relevance at the present time.

Sinusoidal dilatation and congestion in post-transplant liver biopsies from patients presenting with transaminitis

AIMS

Sinusoidal dilatation and congestion (SDC) in liver biopsy may be obstructive (due to venous outflow impairment) or non-obstructive in nature. The significance of this finding in the post-liver transplant setting remains unexplored.

METHODS

We herein retrospectively analysed all post-transplant liver biopsies showing SDC and examined histopathological features in detail. Association with transaminitis and concurrent graft rejection was assessed.

RESULTS

A total of 30 post-transplant liver biopsies from 27 patients showed SDC with atrophy of hepatocyte cords (SDC; incidence 7.4%). All patients had transaminitis. Most patients (n=22; 81.5%) were asymptomatic with deranged liver function tests (LFTs) detected during routine follow-up, raising clinical suspicion of graft rejection. SDC was non-obstructive in 19 (70.4%) and obstructive (due to sinusoidal obstruction syndrome (SOS)) in 8 (29.6%) cases. The incidence of SOS was 2%. SDC was mild, moderate and severe in 18 (66.7%), 7 (25.9%) and 2 (7.4%) cases, respectively. Perivenular and centrilobular sinusoidal fibrosis was seen in the obstructive SDC group (n=3, 11.1%). Concurrent graft rejection was present in 7 (25.9%) cases, of which acute cellular rejection comprised 5 (18.5%), and late acute rejection accounted for 2 cases (7.4%). Serum tacrolimus levels ranged from normal (n=14) to below and above normal (n=5 each). Modulation of immunosuppressive therapy led to normalisation of LFTs in one patient.

CONCLUSION

Obstructive and non-obstructive SDC in post-liver transplant patients presenting with transaminitis mimics graft rejection clinically and may represent a form of drug-induced liver injury. Liver biopsy plays a crucial role in the diagnosis.