Hepatic encephalopathy as an unusual late complication of transjugular intrahepatic portosystemic shunt insertion for non-cirrhotic portal hypertension caused by nodular regenerative hyperplasia in an HIV-positive patient on highly active antiretroviral therapy

The Link between Gut Microbiota and Hepatic Encephalopathy

Hepatic encephalopathy (HE) is a serious complication of cirrhosis that causes neuropsychiatric problems, such as cognitive dysfunction and movement disorders. The link between the microbiota and the host plays a key role in the pathogenesis of HE. The link between the gut microbiome and disease can be positively utilized not only in the diagnosis area of HE but also in the treatment area. Probiotics and prebiotics aim to resolve gut dysbiosis and increase beneficial microbial taxa, while fecal microbiota transplantation aims to address gut dysbiosis through transplantation (FMT) of the gut microbiome from healthy donors. Antibiotics, such as rifaximin, aim to improve cognitive function and hyperammonemia by targeting harmful taxa. Current treatment regimens for HE have achieved some success in treatment by targeting the gut microbiota, however, are still accompanied by limitations and problems. A focused approach should be placed on the establishment of personalized trial designs and therapies for the improvement of future care. This narrative review identifies factors negatively influencing the gut–hepatic–brain axis leading to HE in cirrhosis and explores their relationship with the gut microbiome. We also focused on the evaluation of reported clinical studies on the management and improvement of HE patients with a particular focus on microbiome-targeted therapy.

Cognitive Impairement in Non-Cirrhotic Portal Hypertension: Highlights on Physiopathology, Diagnosis and Management

Hepatic encephalopathy (HE) is one of the most frequent complications of cirrhosis. Several studies and case reports have shown that cognitive impairment may also be a tangible complication of portal hypertension secondary to chronic portal vein thrombosis and to porto-sinusoidal vascular disease (PSVD). In these conditions, representing the main causes of non-cirrhotic portal hypertension (NCPH) in the Western world, both overt and minimal/covert HE occurs in a non-neglectable proportion of patients, even lower than in cirrhosis, and it is mainly sustained by the presence of large porto-systemic shunt. In these patients, the liver function is usually preserved or only mildly altered, and the development of porto-systemic shunt is either spontaneous or iatrogenically frequent; HE is an example of type-B HE. To date, in the absence of strong evidence and large cooperative studies, for the diagnosis and the management of HE in NCPH, the same approach used for HE occurring in cirrhosis is applied. The aim of this paper is to provide an overview of type B hepatic encephalopathy, focusing on its pathophysiology, diagnostic tools and management in patients affected by porto-sinusoidal vascular disease and chronic portal vein thrombosis.

Human immunodeficiency virus and nodular regenerative hyperplasia of liver: A systematic review

AIM: To investigate the diagnosis, pathogenesis, natural history, and management of nodular regenerative hyperplasia (NRH) in patients with human immunodeficiency virus (HIV).

METHODS: We performed a systematic review of the medical literature regarding NRH in patients with HIV. Inclusion criteria include reports with biopsy proven NRH. We studied the clinical features of NRH, in particular, related to its presenting manifestation and laboratory values. Combinations of the following keywords were implemented: “nodular regenerative hyperplasia”, “human immunodeficiency virus”, “noncirrhotic portal hypertension”, “idiopathic portal hypertension”, “cryptogenic liver disease”, “highly active antiretroviral therapy” and “didanosine”. The bibliographies of these studies were subsequently searched for any additional relevant publications.

RESULTS: The clinical presentation of patients with NRH varies from patients being completely asymptomatic to the development of portal hypertension – namely esophageal variceal bleeding and ascites. Liver associated enzymes are generally normal and synthetic function well preserved. There is a strong association between the occurrence of NRH and the use of antiviral therapies such as didanosine. The management of NRH revolves around treating the manifestations of portal hypertension. The prognosis of NRH is generally good since liver function is preserved. A high index of suspicion is required to make a identify NRH.

CONCLUSION: The appropriate management of HIV-infected persons with suspected NRH is yet to be outlined. However, NRH is a clinically subtle condition that is difficult to diagnose, and it is important to be able to manage it according to the best available evidence.

Noncirrhotic hyperammonaemic encephalopathy

Adult hyperammonaemia is associated with severe liver disease in 90% of cases. In the remainder, noncirrhotic causes should be considered. Measurements of serum ammonia level must be part of the basic work-up in all patients presenting with encephalopathy of unknown origin, even when liver function is normal. Clinician awareness of noncirrhotic hyperammonaemic encephalopathy can contribute to early diagnosis and the initiation of sometimes life-saving treatment. This review focuses on the physiology, aetiology and underlying mechanisms of noncirrhotic hyperammonaemic encephalopathy and discusses the available treatment modalities.

Nodular regenerative hyperplasia: Evolving concepts on underdiagnosed cause of portal hypertension

Nodular regenerative hyperplasia (NRH) is a rare liver condition characterized by a widespread benign transformation of the hepatic parenchyma into small regenerative nodules. NRH may lead to the development of non-cirrhotic portal hypertension. There are no published systematic population studies on NRH and our current knowledge is limited to case reports and case series. NRH may develop via autoimmune, hematological, infectious, neoplastic, or drug-related causes. The disease is usually asymptomatic, slowly or non-progressive unless complications of portal hypertension develop. Accurate diagnosis is made by histopathology, which demonstrates diffuse micronodular transformation without fibrous septa. Lack of perinuclear collagen tissue distinguishes NRH from typical regenerative nodules in the cirrhotic liver. While the initial treatment is to address the underlying disease, ultimately the therapy is directed to the management of portal hypertension. The prognosis of NRH depends on both the severity of the underlying illness and the prevention of secondary complications of portal hypertension. In this review we detail the epidemiology, pathogenesis, diagnosis, management, and prognosis of NRH.

Noncirrhotic portal hypertension in HIV-infected patients: a case control evaluation and review of the literature

Idiopathic noncirrhotic portal hypertension (NCPH) is an infrequent but possibly underestimated cryptogenetic liver disease recently described in small series of HIV-infected patients. The exposure to antiretroviral drugs, a direct role of HIV itself, microbial translocation from the gut, or a thrombophilic propensity have been suggested as possible pathogenic mechanisms. In this case control study, we describe 11 HIV-infected patients with idiopathic NCPH and compare the activity of protein C and S, and soluble CD14 levels (a surrogate marker of the translocation of intestinal bacterial products) with 10 age- and gender-matched HIV-infected controls with no liver disease. The clinical presentation of the 11 patients with NCPH was characterised by acute variceal bleeding (2/11), ascites (2/11), portal thrombosis (2/11), and ultrasonographic and endoscopic signs of portal hypertension (11/11), with slightly high alanine transaminase (ALT) and γglutamyl transpeptidase (γ-GT) levels. The FibroScan median liver stiffness was 8.1 kPa, which is inconsistent with significant fibrosis, and nodular regenerative hyperplasia was diagnosed in the 5 patients who underwent liver biopsy. The NCPH patients showed no impairment of hepatic synthesis, but had lower serum albumin levels and a higher international normalized ratio (INR) than the controls (p = 0.01), and lower protein C and S activity, although within the normal range (p = 0.02 and 0.3, respectively). No significant difference in soluble CD14 was seen between the two groups. In conclusion, the etiology of NCHP is not still established, but in order to prevent the dramatic complications of portal hypertension, all HIV-infected patients with unexplained liver enzyme abnormalities or thrombocytopenia should be considered for further investigations by means of thrombophilic screening, Doppler ultrasound evaluation, and in the presence of portal hypertension, endoscopy and liver biopsy.

Clinical syndromes and consequences of antiretroviral-related hepatotoxicity

Highly active antiretroviral therapy (HAART)-related hepatotoxicity complicates the management of patients infected with human immunodeficiency virus (HIV), increases medical costs, alters the prescription patterns, and affects the guideline recommendations. Among the clinical consequences derived from HAART-related liver toxicity, hypersensitivity reactions and lactic acidosis are recognized as acute events with potential to evolve into fatal cases, whereas there seems to be other syndromes not as well characterized but of equal concern as possible long-term liver complications. Belonging to the latter category of syndrome, HAART-related nonalcoholic steatohepatitis, liver fibrosis, portal hypertension, and nodular regenerative hyperplasia are discussed in this review. Updated information on liver toxicity of current antiretroviral drugs, including the most recently licensed, is provided. Management and prevention of liver toxicity among HIV-infected patients treated with HAART are reviewed as well.