End-stage liver disease secondary to hepatitis C virus (HCV) infection is the major indication for orthotopic liver transplantation (OLT) worldwide. It also has a negative impact on patient and graft survival leading to an inferior transplant outcome when compared to other liver transplant indications. The percentage of HCV patients infected with genotype 4 (G4) among recipients of OLT varies depending on geographic location. In the Middle East G4 infection is the most common genotype among transplant recipients. Direct antiviral agents (DAAs) have revolutionized the management of HCV infection in the pre- and post-transplant setting. Recent clinical trials have shown high sustained virologic response rates, shorter durations of treatment, and decreased adverse events when compared with the previous treatment of pegylated interferon (PEG-IFN)-based therapy. However, most of these studies were performed in HCV-G1-infected patients. Due to the low prevalence of HCV-G4 in Europe and the USA, this genotype has not been adequately studied in prospective trials evaluating treatment outcomes. The aim of this chapter is to summarize the natural history and treatment outcome of HCV-G4 in the liver transplant setting, with particular attention to new HCV therapies.
Part of the book: Advances in Treatment of Hepatitis C and B
Ascites refer to accumulation of fluids in the peritoneal cavity. Ascites is caused by multiple causes, among which liver cirrhosis is the commonest. Confirming the etiology is the first and most important step toward proper management. Assuming that ascites is always caused by cirrhosis can lead to unnecessarily sending patients with different etiologies for liver transplantation, particularly patients with non-cirrhotic portal hypertension. Calculating serum albumin ascitic gradient is important in differentiating ascites due to portal hypertension from other etiologies. The first-line therapy for ascites in cirrhosis is low salt diet and diuretics. It is important to avoid nonsteroidal anti-inflammatory drugs (NSAIDs) and nephrotoxic medications in these patients.
Part of the book: Ascites
Liver cirrhosis is associated with a wide range of systemic and pulmonary vascular abnormalities. Cardiac dysfunction also occurs in patients with advanced liver disease (cirrhotic cardiomyopathy). The circulation in cirrhosis is hyperdynamic, which is typically characterized by hypotension resulting from the associated vasodilatation and reflex tachycardia. The circulatory dysfunction in cirrhosis is the proposed pathophysiological mechanism leading to sodium and water retention in patients with liver cirrhosis. Hyperdynamic circulation is triggered by increased intrahepatic resistance due to cirrhosis, leading to a progressive increase in portal venous pressure. As portal hypertension worsens, local production of vasodilators increases due to endothelial activation, leading to splanchnic and systemic arterial vasodilation. Nitric oxide (NO) is considered one of the most important vasodilator molecules in the splanchnic and systemic circulation. The reduction in the effective arterial blood volume results in diminished renal arterial blood flow and subsequently triggers the rennin-angiotensin-aldosterone system (RAAS), antidiuretic hormones (ADHs) and sympathetic nervous system (SNS), leading to renal artery vasoconstriction. All these changes lead to sodium retention and volume expansion, manifested as ascites and peripheral edema. Furthermore, disease progression is associated with various degrees of renal dysfunction.
Part of the book: Ascites