Fatty liver persisting for up to 33 years. A follow-up of the inversen-roholm liver biopsy material

Frontiers of Collaboration between Primary Care and Specialists in the Management of Metabolic Dysfunction-Associated Steatotic Liver Disease: A Review

Metabolic dysfunction-associated steatotic liver disease (MASLD), formerly known as nonalcoholic fatty liver disease (NAFLD), is the most common liver disease. It has a rapidly growing patient population owing to the increasing prevalence of obesity and type 2 diabetes. Patients with MASLD are primarily treated by family physicians when fibrosis is absent or mild and by gastroenterologists/hepatologists when fibrosis is more advanced. It is imperative that a system for the appropriate treatment and surveillance of hepatocellular carcinoma be established in order to ensure that highly fibrotic cases are not overlooked among the large number of MASLD patients. Family physicians should check for viral hepatitis, autoimmune hepatitis, alcoholic liver disease, and drug-induced liver disease, and should evaluate fibrosis using NIT; gastroenterologists/hepatologists should perform liver biopsy, ultrasound elastography (260 units in Japan as of October 2023), and MR elastography (35 units in Japan as of October 2023). This review presents the latest findings in MASLD and the role, accuracy, and clinical use of NIT. It also describes the collaboration between Japanese primary care and gastroenterologists/hepatologists in Japan in the treatment of liver diseases, including MASLD.

Clinical strategy of diagnosing and following patients with nonalcoholic fatty liver disease based on invasive and noninvasive methods

Nonalcoholic fatty liver disease (NAFLD) is an important cause of chronic liver injury in many countries. The incidence of NAFLD is rising rapidly in both adults and children, because of the currently ongoing epidemics of obesity and type 2 diabetes. Notably, histological liver fibrosis is recognized as the main predictive factor for the overall long-term outcome of NAFLD, including cardiovascular disease and liver-related mortality. Thus, staging of liver fibrosis is essential in determining the prognosis and optimal treatment for patients with NAFLD and in guiding surveillance for the development of hepatocellular carcinoma (HCC). Whereas liver biopsy remains the gold standard for staging liver fibrosis, it is impossible to enforce liver biopsy in all patients with NAFLD. Noninvasive biological markers, scoring systems and noninvasive modalities are increasingly being developed and investigated to evaluate fibrosis stage of NAFLD patients. This review will highlight recent studies on the diagnosis and staging of NAFLD based on invasive (liver biopsy) or noninvasive (biomarker, scoring systems, US-based elastography and MR elastography) methods.

Transitions of histopathologic criteria for diagnosis of nonalcoholic fatty liver disease during the last three decades

Nonalcoholic fatty liver disease (NAFLD) is the hepatic manifestation of metabolic syndrome, and is the most common type of chronic liver diseases in the majority of developed countries. NAFLD shows a wide spectrum of disorders including simple steatosis, nonalcoholic steatohepatitis (NASH), and cirrhosis. While simple steatosis is recognized to be benign and stable, NASH is considered to be an aggressive form of the disease progressing to cirrhosis. Currently, differentiation between NASH and simple steatosis can be done only by liver biopsy. Despite many proposals and revisions, the histological criteria for the differentiation have not been perfected yet. In this review article, the changes in the histopathologic criteria of NAFLD during the last three decades are summarized, and perspectives of the future changes are demonstrated. The discussion focuses on how pathologists have been dealing with “hepatocellular ballooning”. Loose criteria, in which hepatocellular ballooning was not required for the diagnosis of NASH, were applied in many clinical studies published in around 2000’s, whereas a strict criterion based on the presence/absence of hepatocellular ballooning was approved recently. Hence, simple and reliable methods of identifying ballooned hepatocytes are being sought. Clinical and pathological predictors of NAFLD-related hepatocarcinogenesis will also be sought in the future.

[Epidemiology and natural history of primary nonalcoholic fatty liver disease]

The clinical impact of nonalcoholic fatty liver disease depends on its prevalence and natural history. The prevalence in the adult population is estimated to be about 23% and is on the increase. Thus, it has become the most common cause of persistent elevated liver enzymes, chronic liver disease, and cryptogenic cirrhosis in developed countries. The increasing prevalence of nonalcoholic fatty liver disease, which is approaching epidemic proportions, is parallel to that of other disorders associated with insulin resistance, especially obesity and type 2 diabetes mellitus. This entity occurs in men and women equally and in all age groups. The natural history is poorly defined mainly due to the scarcity of histologic follow-up studies. Although steatosis alone has a more benign clinical course, steatohepatitis is a progressive fibrotic disease, in which cirrhosis and liver-related death occur in a similar way to other causes of chronic liver diseases. Progression seems to be mainly dependent on the severity of histological damage at diagnosis, but age older than 40 years, obesity, and type 2 diabetes have also been associated with an increased risk of liver fibrosis and progression to cirrhosis.

The evolution of severe steatosis after bariatric surgery is related to insulin resistance

BACKGROUND & AIMS

In severely obese patients, factors implicated in the evolution of severe steatosis after bariatric surgery remain unresolved. Our aim was to determine whether insulin resistance (IR) influences the histologic effects induced by bariatric surgery.

METHODS

We prospectively included 185 severely obese patients (body mass index >/=35 kg/m(2)) referred for bariatric surgery. The evolution of IR (IR index = 1/quantitative insulin sensitivity check index) and liver injury with consecutive biopsy was concomitantly assessed before and 1 year after surgery.

RESULTS

At preoperative biopsy, 27% of severely obese patients disclosed severe steatosis (>/=60%). The alanine aminotransferase (P = .01) and IR indexes (P = .04) were independent predictive factors of severe steatosis at baseline. One year after surgery, surgical treatment induced a decrease in body mass index (9.5 kg/m(2); P < .0001), steatosis score (8.5%; P < .0001), and IR index (0.29; P < .0001). The preoperative IR index (P = .01) and preoperative steatosis (P = .006) were independent predictive factors in the persistence of severe steatosis after surgery. Moderate or severe steatosis was more frequently observed in patients who had conserved a higher IR index after surgery than in patients who had improved their IR index (44% vs 20.2%; P = .04).

CONCLUSIONS

IR was independently associated with severe steatosis and predicted its persistence after surgery. The amelioration of IR after surgery is associated with a decrease in the amount of fat. Taken together, the results of this prospective study in severely obese patients demonstrate that severe steatosis and its evolution after surgery are intimately connected with IR.

Fibrosis heterogeneity in nonalcoholic steatohepatitis and hepatitis C virus needle core biopsy specimens

We examined 46 nonalcoholic steatohepatitis (NASH) and 52 hepatitis C virus (HCV) biopsy specimens to determine the magnitude of fibrosis heterogeneity and minimum length for accurate fibrosis staging. Three fibrosis scores were recorded: lowest regional, highest regional, and most common overall. Mean specimen lengths were 1.6 and 1.8 cm in NASH and HCV, respectively (P = .283). Mean (highest minus lowest) fibrosis heterogeneity scores (highest regional fibrosis - lowest regional fibrosis) were 3.7 and 2.0 in NASH and HCV, respectively (P < .001). Of 36 NASH specimens longer than 1.0 cm, 31 (86%) had the highest regional fibrosis in the deepest sampled parenchyma. Shorter specimens were associated significantly with greater fibrosis heterogeneity in NASH (coefficient, -1.3; P < .001) but not in HCV (P = .901). NASH specimens longer than 1.6 cm had significantly lower mean heterogeneity scores than specimens 1.6 cm or shorter (1.2 vs 3.4; P = .012). In NASH, fibrosis heterogeneity can be substantial and is greater than in HCV, and parenchymal injury, fibrosis, and healing might vary in different regions of the liver. The fibrosis stage in patients with NASH might not be assessed accurately in short specimens. Individual needle cores should be longer than 1.6 cm in NASH for accurate fibrosis staging.

Nonalcoholic steatohepatitis: summary of an AASLD Single Topic Conference

Fatty liver disease that develops in the absence of alcohol abuse is recognized increasingly as a major health burden. This report summarizes the presentations and discussions at a Single Topic Conference held September 20-22, 2002, and sponsored by the American Association for the Study of Liver Diseases. The conference focused on fatty liver disorders. Estimates based on imaging and autopsy studies suggest that about 20% to 30% of adults in the United States and other Western countries have excess fat accumulation in the liver. About 10% of these individuals, or fully 2% to 3% of adults, are estimated to meet current diagnostic criteria for nonalcoholic steatohepatitis (NASH). Sustained liver injury leads to progressive fibrosis and cirrhosis in a fraction, possibly up to one third, of those with NASH, and NASH may be a cause of cryptogenic cirrhosis. NASH is now a significant health issue for obese children as well, leading to cirrhosis in some. The diagnostic criteria for NASH continue to evolve and rely on the histologic findings of steatosis, hepatocellular injury (ballooning, Mallory bodies), and the pattern of fibrosis. Generally recognized indications for biopsy include establishing the diagnosis and staging of the injury, but strict guidelines do not exist. Liver enzymes are insensitive and cannot be used reliably to confirm the diagnosis or stage the extent of fibrosis. Older age, obesity, and diabetes are predictive of fibrosis. The pathogenesis of NASH is multifactorial. Insulin resistance may be an important factor in the accumulation of hepatocellular fat, whereas excess intracellular fatty acids, oxidant stress, adenosine triphosphate (ATP) depletion, and mitochondrial dysfunction may be important causes of hepatocellular injury in the steatotic liver. Efforts are underway to refine the role of insulin resistance in NASH and determine whether improving insulin sensitivity pharmacologically is an effective treatment. An altered lifestyle may be a more effective means of improving insulin sensitivity. The research agenda for the future includes establishing the role of insulin resistance and abnormal lipoprotein metabolism in NASH, determining the pathogenesis of cellular injury, defining predisposing genetic abnormalities, identifying better noninvasive predictors of disease, and defining effective therapy.

Recurrence of nonalcoholic steatohepatitis following liver transplantation

Patients with nonalcoholic steatohepatitis (NASH) may develop progressive liver dysfunction necessitating liver transplantation (OLT). We report the incidence of recurrent disease and outcome in patients undergoing OLT for NASH. Patients transplanted for NASH were identified according to pretransplant and explant liver histology. Patients with significant alcohol consumption were excluded. Medical records were reviewed to extract pre- and posttransplant data, including sequential body weight, biochemistry, and graft histology. Of 622 liver explants, eight patients had features consistent with NASH. All patients were female with a median age of 58. Seven patients were diagnosed with NASH preoperatively, including three who had undergone jejunoileal bypass. One patient was diagnosed as cryptogenic cirrhosis. At a median of 15 months following OLT, all of the eight patients were alive with no graft failure. Six patients developed persistent fatty infiltration in their graft, three of whom had accompanying hepatocellular degeneration, consistent with a diagnosis of recurrent NASH. In two patients, transition from mild steatosis to steatohepatitis and early fibrosis was observed over one to two years. The patients who did not develop recurrent steatosis had significant weight loss following transplantation, although the length of follow-up was relatively short. Patients undergoing OLT for NASH may develop recurrent steatosis shortly after transplantation, with possible progression to steatohepatitis and fibrosis. Although longer follow-up is necessary to determine the eventual prognosis related to the recurrent fat and fibrosis in the graft, patients with endstage liver disease due to NASH should be considered good candidates for OLT.

Nonalcoholic steatohepatitis and cirrhosis with Mallory's hyalin with ultrastructural study of one case

Clinical features and liver biopsy findings were studied in six patients with nonalcoholic steatohepatitis associated with hyalin. A comparative study was made on the ultrastructure of the hyalin in one patient with nonalcoholic steatohepatitis and in one patient with alcoholic hepatitis. The patients, all over 50 years old, comprised two females and one male with steatohepatitis and three females with micronodular cirrhosis. They showed obesity, hepatomegaly, and mild abnormalities on laboratory tests. Three of them showed maturity-onset diabetes. The hyalin was found in the cytoplasm of swollen hepatocytes of the centrilobular or in the peripheral region of nodules and was accompanied by necrosis. Ultrastructurally, the hyalin comprised filamentous structures and vesicular or angular structures resembling disorganized circular or branched rough endoplasmic reticulum. It resembled that found in the liver of patients with alcoholic hepatitis.

Liver dysfunction in hypertension

Liver-function tests measured routinely in hypertensive patients attending the Glasgow Blood Pressure Clinic were abnormal in 15-8% of men and 6-2% of women. The patients studied appeared to be representative of the whole clinic population. Liver dysfunction was related to alcohol consumption, heavy body-weight, male sex, young age, and higher diastolic blood-pressure. It is suggested that alcohol and obesity were the principal causal factors and that fatty infiltration of the liver was the probable pathology. Liver dysfunction was unrelated to treatment. Alcohol use was found to be heavy in 12% of male patients attending the clinic, and this was probably an underestimate. The possibility that alcohol abuse may have a causal role in hypertension needs further study.