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Madir A, Grgurevic I, Tsochatzis EA, Pinzani M. Portal hypertension in patients with nonalcoholic fatty liver disease: Current knowledge and challenges. World J Gastroenterol 2024; 30:290-307. [PMID: 38313235 PMCID: PMC10835535 DOI: 10.3748/wjg.v30.i4.290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Revised: 12/19/2023] [Accepted: 01/08/2024] [Indexed: 01/26/2024] Open
Abstract
Portal hypertension (PH) has traditionally been observed as a consequence of significant fibrosis and cirrhosis in advanced non-alcoholic fatty liver disease (NAFLD). However, recent studies have provided evidence that PH may develop in earlier stages of NAFLD, suggesting that there are additional pathogenetic mechanisms at work in addition to liver fibrosis. The early development of PH in NAFLD is associated with hepatocellular lipid accumulation and ballooning, leading to the compression of liver sinusoids. External compression and intra-luminal obstacles cause mechanical forces such as strain, shear stress and elevated hydrostatic pressure that in turn activate mechanotransduction pathways, resulting in endothelial dysfunction and the development of fibrosis. The spatial distribution of histological and functional changes in the periportal and perisinusoidal areas of the liver lobule are considered responsible for the pre-sinusoidal component of PH in patients with NAFLD. Thus, current diagnostic methods such as hepatic venous pressure gradient (HVPG) measurement tend to underestimate portal pressure (PP) in NAFLD patients, who might decompensate below the HVPG threshold of 10 mmHg, which is traditionally considered the most relevant indicator of clinically significant portal hypertension (CSPH). This creates further challenges in finding a reliable diagnostic method to stratify the prognostic risk in this population of patients. In theory, the measurement of the portal pressure gradient guided by endoscopic ultrasound might overcome the limitations of HVPG measurement by avoiding the influence of the pre-sinusoidal component, but more investigations are needed to test its clinical utility for this indication. Liver and spleen stiffness measurement in combination with platelet count is currently the best-validated non-invasive approach for diagnosing CSPH and varices needing treatment. Lifestyle change remains the cornerstone of the treatment of PH in NAFLD, together with correcting the components of metabolic syndrome, using nonselective beta blockers, whereas emerging candidate drugs require more robust confirmation from clinical trials.
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Affiliation(s)
- Anita Madir
- Department of Gastroenterology, Hepatology and Clinical Nutrition, University Hospital Dubrava, Zagreb 10000, Croatia
| | - Ivica Grgurevic
- Department of Gastroenterology, Hepatology and Clinical Nutrition, University Hospital Dubrava, Zagreb 10000, Croatia
- School of Medicine, University of Zagreb, Zagreb 10000, Croatia
- Faculty of Pharmacy and Biochemistry, University of Zagreb, Zagreb 10000, Croatia
| | - Emmanuel A Tsochatzis
- UCL Institute for Liver and Digestive Health, Royal Free Hospital and University College London, London NW3 2PF, United Kingdom
| | - Massimo Pinzani
- UCL Institute for Liver and Digestive Health, Royal Free Hospital and University College London, London NW3 2PF, United Kingdom
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Mitten EK, Portincasa P, Baffy G. Portal Hypertension in Nonalcoholic Fatty Liver Disease: Challenges and Paradigms. J Clin Transl Hepatol 2023; 11:1201-1211. [PMID: 37577237 PMCID: PMC10412712 DOI: 10.14218/jcth.2023.00029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 05/04/2023] [Accepted: 05/17/2023] [Indexed: 07/03/2023] Open
Abstract
Portal hypertension in cirrhosis is defined as an increase in the portal pressure gradient (PPG) between the portal and hepatic veins and is traditionally estimated by the hepatic venous pressure gradient (HVPG), which is the difference in pressure between the free-floating and wedged positions of a balloon catheter in the hepatic vein. By convention, HVPG≥10 mmHg indicates clinically significant portal hypertension, which is associated with adverse clinical outcomes. Nonalcoholic fatty liver disease (NAFLD) is a common disorder with a heterogeneous clinical course, which includes the development of portal hypertension. There is increasing evidence that portal hypertension in NAFLD deserves special considerations. First, elevated PPG often precedes fibrosis in NAFLD, suggesting a bidirectional relationship between these pathological processes. Second, HVPG underestimates PPG in NAFLD, suggesting that portal hypertension is more prevalent in this condition than currently believed. Third, cellular mechanoresponses generated early in the pathogenesis of NAFLD provide a mechanistic explanation for the pressure-fibrosis paradigm. Finally, a better understanding of liver mechanobiology in NAFLD may aid in the development of novel pharmaceutical targets for prevention and management of this disease.
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Affiliation(s)
- Emilie K. Mitten
- Division of Gastroenterology, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Piero Portincasa
- Division of Internal Medicine and Department of Precision and Regenerative Medicine and Ionian Area, University ‘Aldo Moro’ Medical School, Bari, Italy
| | - György Baffy
- Division of Gastroenterology, Hepatology and Endoscopy, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
- Section of Gastroenterology, Department of Medicine, VA Boston Healthcare System, Boston, MA, USA
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Baidya R, Crawford DHG, Gautheron J, Wang H, Bridle KR. Necroptosis in Hepatosteatotic Ischaemia-Reperfusion Injury. Int J Mol Sci 2020; 21:ijms21165931. [PMID: 32824744 PMCID: PMC7460692 DOI: 10.3390/ijms21165931] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 08/12/2020] [Accepted: 08/12/2020] [Indexed: 02/07/2023] Open
Abstract
While liver transplantation remains the sole treatment option for patients with end-stage liver disease, there are numerous limitations to liver transplantation including the scarcity of donor livers and a rise in livers that are unsuitable to transplant such as those with excess steatosis. Fatty livers are susceptible to ischaemia-reperfusion (IR) injury during transplantation and IR injury results in primary graft non-function, graft failure and mortality. Recent studies have described new cell death pathways which differ from the traditional apoptotic pathway. Necroptosis, a regulated form of cell death, has been associated with hepatic IR injury. Receptor-interacting protein kinase 3 (RIPK3) and mixed-lineage kinase domain-like pseudokinase (MLKL) are thought to be instrumental in the execution of necroptosis. The study of hepatic necroptosis and potential therapeutic approaches to attenuate IR injury will be a key factor in improving our knowledge regarding liver transplantation with fatty donor livers. In this review, we focus on the effect of hepatic steatosis during liver transplantation as well as molecular mechanisms of necroptosis and its involvement during liver IR injury. We also discuss the immune responses triggered during necroptosis and examine the utility of necroptosis inhibitors as potential therapeutic approaches to alleviate IR injury.
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Affiliation(s)
- Raji Baidya
- Faculty of Medicine, The University of Queensland, Brisbane, Queensland QLD 4006, Australia; (R.B.); (D.H.G.C.)
- Gallipoli Medical Research Institute, Brisbane, Queensland QLD 4120, Australia;
| | - Darrell H. G. Crawford
- Faculty of Medicine, The University of Queensland, Brisbane, Queensland QLD 4006, Australia; (R.B.); (D.H.G.C.)
- Gallipoli Medical Research Institute, Brisbane, Queensland QLD 4120, Australia;
| | - Jérémie Gautheron
- Sorbonne University, Inserm, Centre de Recherche Saint-Antoine (CRSA), 75012 Paris, France;
- Institute of Cardiometabolism and Nutrition (ICAN), 75013 Paris, France
| | - Haolu Wang
- Gallipoli Medical Research Institute, Brisbane, Queensland QLD 4120, Australia;
- Diamantina Institute, The University of Queensland, Brisbane, Queensland QLD 4102, Australia
| | - Kim R. Bridle
- Faculty of Medicine, The University of Queensland, Brisbane, Queensland QLD 4006, Australia; (R.B.); (D.H.G.C.)
- Gallipoli Medical Research Institute, Brisbane, Queensland QLD 4120, Australia;
- Correspondence: ; Tel.: +61-7-3346-0698
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Ryou M, Stylopoulos N, Baffy G. Nonalcoholic fatty liver disease and portal hypertension. EXPLORATION OF MEDICINE 2020; 1:149-169. [PMID: 32685936 DOI: 10.37349/emed.2020.00011] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Nonalcoholic fatty liver disease (NAFLD) is a substantial and growing problem worldwide and has become the second most common indication for liver transplantation as it may progress to cirrhosis and develop complications from portal hypertension primarily caused by advanced fibrosis and erratic tissue remodeling. However, elevated portal venous pressure has also been detected in experimental models of fatty liver and in human NAFLD when fibrosis is far less advanced and cirrhosis is absent. Early increases in intrahepatic vascular resistance may contribute to the progression of liver disease. Specific pathophenotypes linked to the development of portal hypertension in NAFLD include hepatocellular lipid accumulation and ballooning injury, capillarization of liver sinusoidal endothelial cells, enhanced contractility of hepatic stellate cells, activation of Kupffer cells and pro-inflammatory pathways, adhesion and entrapment of recruited leukocytes, microthrombosis, angiogenesis and perisinusoidal fibrosis. These pathological events are amplified in NAFLD by concomitant visceral obesity, insulin resistance, type 2 diabetes and dysbiosis, promoting aberrant interactions with adipose tissue, skeletal muscle and gut microbiota. Measurement of the hepatic venous pressure gradient by retrograde insertion of a balloon-tipped central vein catheter is the current reference method for predicting outcomes of cirrhosis associated with clinically significant portal hypertension and guiding interventions. This invasive technique is rarely considered in the absence of cirrhosis where currently available clinical, imaging and laboratory correlates of portal hypertension may not reflect early changes in liver hemodynamics. Availability of less invasive but sufficiently sensitive methods for the assessment of portal venous pressure in NAFLD remains therefore an unmet need. Recent efforts to develop new biomarkers and endoscopy-based approaches such as endoscopic ultrasound-guided measurement of portal pressure gradient may help achieve this goal. In addition, cellular and molecular targets are being identified to guide emerging therapies in the prevention and management of portal hypertension.
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Affiliation(s)
- Marvin Ryou
- Department of Medicine, Division of Gastroenterology, Hepatology and Endoscopy, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Nicholas Stylopoulos
- Division of Endocrinology, Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA.,The Broad Institute of MIT and Harvard, Cambridge MA
| | - Gyorgy Baffy
- Department of Medicine, Division of Gastroenterology, Hepatology and Endoscopy, Brigham and Women's Hospital, Harvard Medical School, Boston, MA.,Department of Medicine, VA Boston Healthcare System, Harvard Medical School, Boston, MA
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Parker KJ, Ormachea J, Drage MG, Kim H, Hah Z. The biomechanics of simple steatosis and steatohepatitis. ACTA ACUST UNITED AC 2018; 63:105013. [DOI: 10.1088/1361-6560/aac09a] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Tashiro H, Kuroda S, Mikuriya Y, Ohdan H. Ischemia–reperfusion injury in patients with fatty liver and the clinical impact of steatotic liver on hepatic surgery. Surg Today 2015; 44:1611-25. [PMID: 24078000 DOI: 10.1007/s00595-013-0736-9] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Accepted: 08/22/2013] [Indexed: 12/15/2022]
Abstract
Hepatic steatosis is one of the most common hepatic disorders in developed countries. The epidemic of obesity in developed countries has increased with its attendant complications, including metabolic syndrome and non-alcoholic fatty liver disease. Steatotic livers are particularly vulnerable to ischemia/reperfusion injury, resulting in an increased risk of postoperative morbidity and mortality after liver surgery, including liver transplantation. There is growing understanding of the molecular and cellular mechanisms and therapeutic approaches for treating ischemia/reperfusion injury in patients with steatotic livers. This review discusses the mechanisms underlying the susceptibility of steatotic livers to ischemia/reperfusion injuries, such as mitochondrial dysfunction and signal transduction alterations, and summarizes the clinical impact of steatotic livers in the setting of hepatic resection and liver transplantation. This review also describes potential therapeutic approaches, such as ischemic and pharmacological preconditioning, to prevent ischemia/reperfusion injury in patients with steatotic livers. Other approaches, including machine perfusion, are also under clinical investigation; however, many pharmacological approaches developed through basic research are not yet suitable for clinical application.
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Tsushima Y, Endo K. Spleen enlargement in patients with nonalcoholic fatty liver: correlation between degree of fatty infiltration in liver and size of spleen. Dig Dis Sci 2000. [PMID: 10695635 DOI: 10.1023/a: 1005446418589] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/15/2023]
Abstract
Our purpose was to determine if there is an association between nonalcoholic fatty liver and spleen enlargement. Spleen volume was measured by computed tomography (CT) in 32 patients with nonalcoholic fatty liver (23 men and 9 women; age, 41.6+/-12.1, range, 22-69 years) and 34 patients with normal liver (19 men and 15 women; age, 51.1+/-16.2, range, 14-86 years). The values were compared with the patient's demographic data, the liver-to-spleen (L/S) ratio of CT Hounsefield unit measurements, and the results of liver function tests. Diagnosis of fatty liver was made if the L/S ratio was less than 1.0. The mean spleen volume was 73.0+/-24.4 cm3 (range, 21.1-106.1) in normal subjects and 141.2+/-54.1 cm3 (range, 44.1-267.3) in patients with fatty liver (P<0.0001). Multivariate linear regression analysis identified that only the L/S ratio (P<0.0001) and age (P<0.01) were significantly correlated with spleen volume. Using forward selection stepwise regression, the L/S ratio entered first (beta = -0.634) and age second (beta = -0.293). In conclusion, spleen enlargement was commonly seen in patients with nonalcoholic fatty liver, and the recognition of this association may halt further attempts to evaluate the cause of spleen enlargement.
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Affiliation(s)
- Y Tsushima
- Department of Radiology, Motojima General Hospital, Ohta, Gunma, Japan
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Tsushima Y, Endo K. Spleen enlargement in patients with nonalcoholic fatty liver: correlation between degree of fatty infiltration in liver and size of spleen. Dig Dis Sci 2000; 45:196-200. [PMID: 10695635 DOI: 10.1023/a:1005446418589] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Abstract
Our purpose was to determine if there is an association between nonalcoholic fatty liver and spleen enlargement. Spleen volume was measured by computed tomography (CT) in 32 patients with nonalcoholic fatty liver (23 men and 9 women; age, 41.6+/-12.1, range, 22-69 years) and 34 patients with normal liver (19 men and 15 women; age, 51.1+/-16.2, range, 14-86 years). The values were compared with the patient's demographic data, the liver-to-spleen (L/S) ratio of CT Hounsefield unit measurements, and the results of liver function tests. Diagnosis of fatty liver was made if the L/S ratio was less than 1.0. The mean spleen volume was 73.0+/-24.4 cm3 (range, 21.1-106.1) in normal subjects and 141.2+/-54.1 cm3 (range, 44.1-267.3) in patients with fatty liver (P<0.0001). Multivariate linear regression analysis identified that only the L/S ratio (P<0.0001) and age (P<0.01) were significantly correlated with spleen volume. Using forward selection stepwise regression, the L/S ratio entered first (beta = -0.634) and age second (beta = -0.293). In conclusion, spleen enlargement was commonly seen in patients with nonalcoholic fatty liver, and the recognition of this association may halt further attempts to evaluate the cause of spleen enlargement.
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Affiliation(s)
- Y Tsushima
- Department of Radiology, Motojima General Hospital, Ohta, Gunma, Japan
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