Progress is impossible without change: understanding the evolving nomenclature of steatotic liver disease and its effect on hepatology practice.

The American, European, and Latin American liver societies have proposed a change in the nomenclature we use to describe alcohol-related liver disease and non-alcoholic fatty liver disease. Additionally, a term encompassing both is now advocated: steatotic liver disease, which includes metabolic dysfunction associated steatotic liver disease (MASLD) and MASLD with greater alcohol consumption (MetALD). These classifications offer increased relevance for clinicians, researchers, and patients alike. In this Viewpoint, we discuss the basis for this nomenclature shift and how it was developed. We also explore the challenges that will be faced in the adoption of such change. The proposed change seeks to banish stigma associated with phrasing such as alcoholic and fatty. However stigma, particularly related to the term fatty, is culturally nuanced, and reflects different entities depending on location. If such a change is internationally accepted, there will be wide-reaching effects on practitioners in primary care and metabolic medicine, and on patients. We discuss those effects and the opportunities the nomenclature change could offer, particularly for patients with alcohol and metabolic risk factors who represent a group previously ignored by clinical trials.

New nomenclature for fatty liver disease.

This review investigates that, in 2023, fatty liver disease underwent a name change to "steatotic liver disease" (SLD). SLD now includes metabolic dysfunction-associated steatotic liver disease (MASLD), alcohol-related liver disease (ALD), and metabolic and alcohol-related liver disease (MetALD). The renaming aims to better incorporate alcohol intake and metabolic risk factors into disease classification and to diminish the stigma associated with the previous nomenclature. Early identification of the patient's aetiology is important for the prognosis which can be improved by interventions against the causative risk factors.

[Histopathological diagnosis of non-alcoholic and alcoholic fatty liver disease. Grade 2 consensus-based guidelines]. / Histopathologische Diagnose der nichtalkoholischen und alkoholischen Fettlebererkrankung. Konsensusbasierte Leitlinie der Stufe 2.

Both alcoholic (AFL) and non-alcoholic fatty liver (NAFL) are characterized by lipid deposition in hepatocytes. The diagnosis of steatosis is made when lipid deposition exceeds 5% of hepatocytes, while involvement of more than 50% is called "fatty liver ". An additional inflammatory reaction leads to alcoholic (ASH) or non-alcoholic steatohepatitis (NASH). Steatohepatitis is present when both inflammatory infiltrates of mixed cells in the small liver lobules as well as liver cell injury in terms of ballooning can be detected.Liver biopsy represents the "gold standard" for confirming diagnosis and determining inflammatory activity and potential fibrosis of fatty liver disease.The differential diagnosis of ASH-NASH cannot be made on the basis of histological criteria alone. Steatosis, inflammatory changes and hepatocytic injury can be semiquantified as a "Brunt Score" or "NAS" (NAFLD activity score), providing the basis on which to decide whether or not steatohepatitis is present.People at increased risk of developing a fatty liver possess an increased risk of developing chemotherapy-associated steatohepatitis (CASH).Histologically, pediatric NASH differs from adult NASH and is often only clinically manifest through a mild if persistent elevation in transaminases.

Relationship between Controlled Attenuation Parameter and Hepatic Steatosis as Assessed by Ultrasound in Alcoholic or Nonalcoholic Fatty Liver Disease.

BACKGROUND/AIMS: The aim of this study was to evaluate the relationship between controlled attenuation parameter (CAP) and hepatic steatosis, as assessed by ultrasound (US) in patients with alcoholic liver disease (ALD) or non-alcoholic fatty liver disease (NAFLD). METHODS: Patients with either ALD or NAFLD who were diagnosed with fatty liver with US and whose CAP scores were measured, were retrospectively enrolled in this study. The degree of hepatic steatosis assessed by US was categorized into mild (S1), moderate (S2), and severe (S3). RESULTS: A total of 186 patients were included 106 with NAFLD and 80 with ALD. Regarding hepatic steatosis, the CAP score was significantly correlated with US (ρ=0.580, p<0.001), and there was no significant difference between the NAFLD and ALD groups (ρ=0.569, p<0.001; ρ=0.519, p<0.001; p=0.635). Using CAP, area under receiver operating characteristic curves for ≥ S2 and ≥ S3 steatosis were excellent (0.789 and 0.843, respectively). For sensitivity ≥ 90%, CAP cutoffs for the detection of ≥ S2 and ≥ S3 steastosis were separated with a gap of approximately 35 dB/m in all patients and in each of the NAFLD and ALD groups. CONCLUSIONS: The CAP score is well correlated with hepatic steatosis, as assessed by US, in both ALD and NAFLD.

The use of protein tyrosine phosphatase 1B and insulin receptor immunostains to differentiate nonalcoholic from alcoholic steatohepatitis in liver biopsy specimens.

Nonalcoholic steatohepatitis (NASH) and alcoholic steatohepatitis (ASH) and typically are indistinguishable, histologically. The diagnosis relies on reporting of alcohol consumption. The metabolic syndrome involving insulin resistance is associated with nonalcoholic fatty liver disease (NAFLD). Protein tyrosine phosphatase 1B (PTP1B) negatively regulates the insulin receptor (IR). Increased PTP1B expression is seen in obesity and possibly is responsible for the insulin resistance seen in the metabolic syndrome. The study objective was to determine whether biopsy specimens with steatohepatitis could be classified accurately as alcoholic or nonalcoholic by immunohistochemical stains. We selected 241 cases of steatohepatitis, comprising 53 and 188 cases of alcoholic and NAFLD, respectively. Specimens were stained with PTP1B and IR (b subunit) and classified as NASH or ASH. The staining pattern predicted 60 cases of ASH and 181 cases of NASH. Results correlated with clinical diagnoses in 70% and 88% of ASH and NASH cases, respectively (odds ratio, 16.6; 95% confidence interval, 8.2-35.4).

Multicausality in fatty liver disease: is there a rationale to distinguish between alcoholic and non-alcoholic origin?

Apart from alcohol, there are other factors that may induce complications, which resemble alcohol-related liver disorders. In particular, obesity has been brought into focus as a risk factor for fatty liver disease. The term "non-alcoholic" fatty liver disease is commonly used to distinguish between obesity-related and alcohol-related hepatic steatosis. This review uses the epidemiological perspective to critically assess whether it is necessary and useful to differentiate between alcoholic and "non-alcoholic" fatty liver disease. The MEDLINE database was searched using the PubMed search engine, and a review of reference lists from original research and review articles was conducted. The concept to distinguish between alcoholic and "non-alcoholic" fatty liver disease is mainly based on specific pathomechanisms. This concept has, however, several limitations including the common overlap between alcohol misuse and obesity-related metabolic disorders and the non-consideration of additional causal factors. Both entities share similar histopathological patterns. Studies demonstrating differences in clinical presentation and outcome are often biased by selection. Risk factor reduction is the main principle of prevention and treatment of both disease forms. In conclusion, alcoholic and "non-alcoholic" fatty liver diseases are one and the same disease caused by different risk factors. A shift from artificial categories to a more general approach to fatty liver disease as a multicausal disorder may optimize preventive strategies and help clinicians more effectively treat patients at the individual level.

Histopathological evaluation of fatty and alcoholic liver diseases.

Fatty liver disease (FLD) represents a common form of hepatic dysfunction among adults and children. Recognition of steatosis is usually straightforward but the differential diagnosis is broad. Macrovesicular steatosis may occur due to alcohol use or metabolic factors including obesity and hyperinsulinemia. Steatosis is, in some patients, accompanied by varying degrees of inflammation, ballooning hepatocyte degeneration or fibrosis, or both. The pathologist's recognition and interpretation of these features, when present, is critical for the classification and prognostication of the disease. Recent advances in the study of FLD have yielded new information for the surgical pathologist to guide the interpretation of steatosis in children and adults, and in patients with other forms of liver disease such as chronic viral hepatitis. This article details the current terminology for various forms of FLD, highlights the key histological features and reviews recent advances in the field.