Receiver operating characteristic analysis of glycogenated nuclei in liver biopsy specimens: quantitative evaluation of their relationship with diabetes and obesity

The Liver and Glycogen: In Sickness and in Health

The liver is a major store of glycogen and is essential in maintaining systemic glucose homeostasis. In healthy individuals, glycogen synthesis and breakdown in the liver are tightly regulated. Abnormal glycogen metabolism results in prominent pathological changes in the liver, often manifesting as hepatic glycogenosis or glycogen inclusions. This can occur in genetic glycogen storage disease or acquired conditions with insulin dysregulation such as diabetes mellitus and non-alcoholic fatty liver disease or medication effects. Some primary hepatic tumors such as clear cell hepatocellular carcinoma also demonstrate excessive glycogen accumulation. This review provides an overview of the pathological manifestations and molecular mechanisms of liver diseases associated with abnormal glycogen accumulation.

Steatohepatitic Variant of Hepatocellular Carcinoma Is Associated With Both Alcoholic Steatohepatitis and Nonalcoholic Steatohepatitis: A Study of 2 Cohorts With Molecular Insights

Steatohepatitic hepatocellular carcinoma (SH-HCC) is a variant of hepatocellular carcinoma (HCC) with established association with nonalcoholic steatohepatitis (NASH), while its association with alcoholic steatohepatitis (ASH) is unclear. We studied 2 cohorts of patients who underwent resection for HCC in the setting of steatohepatitis. In our Mount Sinai (New York) cohort, we found SH-HCC in 17/24 (71%) patients with NASH and in 14/19 (74%) patients with ASH, while SH-HCC was the predominant tumor morphology in 12/24 (50%) in the NASH group and 9/19 (47%) in the ASH group. Upon review, 12/19 patients diagnosed with ASH also had diabetes and/or a body mass index >30. When these patients were removed, we still found similar rates of SH-HCC (6/7 [86%] showed SH-HCC, while SH-HCC was predominant in 3/7 [43%]. Interestingly, glycogenated hepatocyte nuclei were seen in the nontumor liver in 4/7 (57%) of these cases. In our Japan cohort, we also found similar rates of SH-HCC in NASH and ASH patients with HCC, 15/58 (26%), and 16/45 (36%), respectively. We determined molecular subclassification of tumors from the Japan cohort and found no difference in the distribution of S1, S2 and S3 subclasses among the ASH and NASH groups, though, among cases of SH-HCC, there was a trend toward an association of ASH with S1 (P=0.054) and NASH with S3 (P=0.052). Our study shows that SH-HCC is common in both ASH and NASH and that both underlying liver diseases produce tumors with similar molecular profiles, though different pathways may underlie the development of SH-HCC in ASH versus NASH.

Characterization of two types of intranuclear hepatocellular inclusions in NAFLD

Nuclear inclusions (NI) are a common finding in hepatocytes from patients with liver disease especially in diabetes mellitus and non-alcoholic fatty liver disease (NAFLD) but studies examining the shape and content of these inclusions in detail are lacking. In this study we define two distinct types of NI in NAFLD: inclusions bounded by the nuclear membrane, containing degenerative cell organelles and heterolysosomes (type1) and inclusions with deposits of glycogen but without any kind of organelles and delimiting membrane (type2). NI in 77 paraffin-embedded patients of NAFLD including NAFL and non-alcoholic steatohepatitis (NASH) were analyzed. In 4–12% of type1 NI immunopositivity for the autophagy-associated proteins LC3B, ubiquitin, p62/sequestosome1, cathepsin D and cathepsin B were detected with co-localizations of ubiquitin and p62; type2 NI showed no immunoreactivity. Three-dimensional reconstructions of isolated nuclei revealed that NI type1 are completely enclosed within the nucleus, suggesting that NI, although probably derived from cytoplasmic invaginations, are not just simple invaginations. Our study demonstrates two morphologically different types of inclusions in NAFLD, whereby both gained significantly in number in advanced stages. We suggest that the presence of autophagy-associated proteins and degenerated organelles within type1 NI plays a role in disease progression.

The Spectrum of Histologic Findings in Hepatic Outflow Obstruction

CONTEXT

-Cardiac hepatopathy and Budd-Chiari syndrome are 2 forms of hepatic venous outflow obstruction with different pathophysiology but overlapping histologic findings, including sinusoidal dilation and centrilobular necrosis.

OBJECTIVE

-To determine whether a constellation of morphologic findings could help distinguish between the 2 and could suggest the diagnoses in previously undiagnosed patients.

DESIGN

-We identified 26 specimens with a diagnosis of cardiac hepatopathy and 23 with a diagnosis of Budd-Chiari syndrome. Slides stained with hematoxylin and eosin and with trichrome were evaluated for several distinctive histologic findings.

RESULTS

-Features common to both forms of hepatic outflow obstruction included sinusoidal dilation and portal tract changes of fibrosis, chronic inflammation, and bile ductular reaction. Histologic findings significantly more common in cardiac hepatopathy included pericellular/sinusoidal fibrosis and fibrosis around the central vein. Only centrilobular hepatocyte dropout/necrosis was significantly more common in Budd-Chiari, regardless of duration.

CONCLUSIONS

-The finding of pericellular/sinusoidal fibrosis in cardiac hepatopathy compared with Budd-Chiari is not unexpected, given the chronic nature of most cardiac hepatopathy. Portal tract changes are common in both forms of hepatic outflow obstruction and should not deter one from making the diagnosis of hepatic outflow obstruction. Fibrosis along sinusoids and around the central vein may be suggestive of cardiac hepatopathy in biopsies from patients without a prior diagnosis.

Mouse Models of Diabetes, Obesity and Related Kidney Disease

Multiple rodent models have been used to study diabetic kidney disease (DKD). The purpose of the present study was to compare models of diabetes and obesity-induced metabolic syndrome and determine differences in renal outcomes. C57BL/6 male mice were fed either normal chow or high fat diet (HFD). At postnatal week 8, chow-fed mice were randomly assigned to low-dose streptozotocin (STZ, 55 mg/kg/day, five consecutive days) or vehicle control, whereas HFD-fed mice were given either one high-dose of STZ (100 mg/kg) or vehicle control. Intraperitoneal glucose tolerance tests were performed at Week 14, 20 and 30. Urinary albumin to creatinine ratio (ACR) and serum creatinine were measured, and renal structure was assessed using Periodic Acid Schiff (PAS) staining at Week 32. Results showed that chow-fed mice exposed to five doses of STZ resembled type 1 diabetes mellitus with a lean phenotype, hyperglycaemia, microalbuminuria and increased serum creatinine levels. Their kidneys demonstrated moderate tubular injury with evidence of tubular dilatation and glycogenated nuclear inclusion bodies. HFD-fed mice resembled metabolic syndrome as they were obese with dyslipidaemia, insulin resistance, and significantly impaired glucose tolerance. One dose STZ, in addition to HFD, did not worsen metabolic features (including fasting glucose, non esterified fatty acid, and triglyceride levels). There were significant increases in urinary ACR and serum creatinine levels, and renal structural changes were predominantly related to interstitial vacuolation and tubular dilatation in HFD-fed mice.

Dysplastic hepatocytes develop nuclear inclusions in a mouse model of viral hepatitis

Viral hepatitis resulting in chronic liver disease is an important clinical challenge and insight into the cellular processes that drive pathogenesis will be critical in order to develop new diagnostic and therapeutic options. Nuclear inclusions in viral and non-viral hepatitis are well documented and have diagnostic significance in some disease contexts. However, the origins and functional consequences of these nuclear inclusions remain elusive. To date the clinical observation of nuclear inclusions in viral and non-viral hepatitis has not been explored at depth in murine models of liver disease. Herein, we report that in a transgenic model of hepatitis B surface antigen mediated hepatitis, murine hepatocytes exhibit nuclear inclusions. Cells bearing nuclear inclusions were more likely to express markers of cell proliferation. We also established a correlation between these inclusions and oxidative stress. N-acetyl cysteine treatment effectively reduced oxidative stress levels, relieved endoplasmic reticulum (ER) stress, and the number of nuclear inclusions we observed in the transgenic mice. Our results suggest that the presence of nuclear inclusions in hepatocytes correlates with oxidative stress and cellular proliferation in a model of antigen mediated hepatitis.

Nuclear Inclusions and Pseudoinclusions: Friends or Foes of the Surgical Pathologist?

Abnormal substances in the nuclei that can be observed by light microscopy are often broadly referred to as nuclear inclusions. Although their recognition in the appropriate clinicopathological settings can aid in the diagnosis of some disease entities and tumor types, they can also be a source of error. There are 2 morphologically distinct types of inclusions with different mechanisms of formation and diagnostic significance, including bona fide nuclear inclusions and nuclear pseudoinclusions. Bona fide nuclear inclusions result from accumulation in the nuclei of viral particles, cytoplasmic materials (such as surfactant, immunoglobulin, and glycogen), biotin, nuclear lamins, or polyglutamine. Some of them are diagnostically helpful, such as surfactant inclusion, which can support the pulmonary origin of an adenocarcinoma, whereas others may be misleading, such as biotin inclusion, which can be mistaken for herpes infection. Nuclear pseudoinclusions, which represent invaginations of cytoplasm into the nucleus, are delimited by the nuclear membrane. Although not totally specific, they are particularly common in papillary thyroid carcinoma, meningioma, and usual ductal hyperplasia of the breast and hence may aid in the diagnosis of these entities. Nuclear pseudo-pseudoinclusions, which are artefactual bubbles in the nuclei that mimic nuclear pseudoinclusions or clear nuclei, can lead to misdiagnosis of follicular adenoma or hyperplastic nodule as papillary thyroid carcinoma.

Serum retinol binding protein 4 and nonalcoholic fatty liver disease in patients with type 2 diabetes mellitus

Retinol binding protein 4 (RBP4) is a protein secreted by adipocytes, and closely associated with insulin resistance. Whereas RBP4 is also mainly expressed in hepatocytes as the principal transport protein for retinol (vitamin A) in the circulation, and its pathophysiological role in liver remain unclear. The aim of this paper was to investigate the association between RBP4 and nonalcoholic fatty liver disease (NAFLD) in patients with type 2 diabetes mellitus (T2DM). Serum RBP4 and adiponectin concentrations were measured by radioimmunoassay in 52 diabetic patients who had NAFLD and 50 sex- and age-matched diabetic patients without any clinical features of liver diseases who had normal liver ultrasonic appearance and normal liver function. Serum RBP4 levels were elevated in diabetic patients with NAFLD (32.0+/-8.9 microg/ml vs. 41.3+/-9.8 microg/ml, p<0.001), while adiponectin decreased (17.4+/-9.3 microg/ml vs. 13.8+/-7.0 microg/ml, p=0.032). Male diabetic patients had higher serum RBP4 concentration and lower serum adiponectin concentration than female diabetic patients (38.5+/-9.9 microg/ml vs. 34.0+/-10.7 microg/ml, p=0.031 and 12.7+/-5.7 microg/ml vs. 20.23+/-9.8 microg/ml, p<0.001, respectively). Multiple logistic regression analysis revealed RBP4 and triglyceride as independent association factors for NAFLD, while the association between serum adiponectin and NAFLD was not significant. Increasing concentrations of RBP4 were independently and significantly associated with NAFLD in diabetic patients. In multiple linear regression analysis, alanine aminotransferase, fasting serum insulin and adiponectin were independent factors for serum RBP4 level. The study demonstrates that retinol binding protein 4 might contribute to the pathogenesis of nonalcoholic fatty liver disease.

Silent non-alcoholic fatty liver disease-a clinical-histological study

BACKGROUND/AIMS

We studied the prevalence of non-alcoholic fatty liver disease and non-alcoholic-steatohepatitis in patients with metabolic-syndrome but normal liver enzymes. The histological findings of patients with normal liver enzymes and non-alcoholic-steatohepatitis were compared with those of a control-group with persistently abnormal liver enzymes.

METHODS

Patients presenting with normal liver enzymes were enrolled in the study and underwent liver biopsy. Prevalence of non-alcoholic-steatohepatitis and risk factors for fibrosis and cirrhosis were evaluated. Data from a control-group with non-alcoholic-steatohepatitis and abnormal liver enzymes were used to compare the histological findings.

RESULTS

Fifty-eight of the 80 patients enrolled had varying degrees of non-alcoholic steatohepatitis, of these 26 had fibrosis and 8 silent cirrhosis. The association of metabolic-syndrome, female-sex, a long-history of obesity and body mass index>45 were considered to be independent risk-factors for fibrosis. Comparing the histological findings of cases and controls we found a similar severity of steatosis and fibrosis, with a greater prevalence of ballooning degeneration and glycogenated-nuclei rather than lobular-inflammation.

CONCLUSIONS

In the subjects selected according to our criteria, liver enzyme levels could not be used as surrogate markers of non-alcoholic-steatohepatitis. Histological hallmarks of patients with metabolic-syndrome, normal liver enzymes and non-alcoholic-steatohepatitis consist to a lesser degree of lobular-inflammation and a more severe ballooning and glycogenated-nuclei.

Hepadnaviral hepatocarcinogenesis: in situ visualization of viral antigens, cytoplasmic compartmentation, enzymic patterns, and cellular proliferation in preneoplastic hepatocellular lineages in woodchucks

BACKGROUND/AIMS

Hepadnaviral hepatocarcinogenesis induced in woodchucks with and without dietary aflatoxin B1 has been established as an appropriate animal model for studying the pathogenesis of human hepatocellular carcinoma in high-risk areas. Our aim in this study was the elucidation of phenotypic cellular changes in early stages of this process.

METHODS

Woodchucks were inoculated as newborns with woodchuck hepatitis virus (WHV), and partly also exposed to aflatoxin B1. Sequential hepatocellular changes in the expression of viral antigens, ultrastructural organization, cellular proliferation and apoptosis were studied in situ by electron microscopy, enzyme and immunohistochemistry.

RESULTS

A characteristic finding in WHV-infected animals (with and without aflatoxin B1) was proliferative areas of minimal structural deviation, which predominated periportally, comprised glycogen-rich, amphophilic, and ground-glass hepatocytes, and expressed the woodchuck hepatitis core and surface antigens. Two main types of proliferative foci emerged from minimal deviation areas, glycogenotic clear cell foci and amphophilic cell foci (being poor in glycogen but rich in mitochondria), giving rise to the glycogenotic-basophilic and the amphophilic preneoplastic hepatocellular lineages. A gradual loss in the expression of viral antigens appeared in both lineages, particularly early in the glycogenotic-basophilic cell lineage. Whereas glycogenosis was associated with an enzymic pattern suggesting an early activation of the insulin-signaling pathway, amphophilic cells showed changes in enzyme activities mimicking a response of the hepatocytes to thyroid hormone, which may also result from early changes in signal transduction.

CONCLUSION

Preneoplastic hepatocellular lineages in hepadnaviral and chemical hepatocarcinognesis show striking phenotypic similarities, indicating concordant and possibly synergistic early changes in signaling.

Nonalcoholic steatohepatitis. Clinicopathological comparison with alcoholic hepatitis in ambulatory and hospitalized patients

This study reports a clinicopathological analysis of 105 patients whose liver histology showed a pattern of alcohol-like steatohepatitis. There were 32 nonalcoholic, 21 asymptomatic ambulatory, and 52 hospitalized alcoholic hepatitis patients. Female sex, obesity, and diabetes predominated in nonalcoholics. Clinical and laboratory presentation were similar in nonalcoholics and ambulatory alcoholics, but different from the hospitalized alcoholics. Histology showed an increasing degree of severity of hepatocellular damage, Mallory bodies, neutrophil and mononuclear infiltration, and pericellular and portal fibrosis from the nonalcoholics to the hospitalized alcoholics, with ambulatory alcoholics displaying an intermediate degree of severity. Steatosis and glycogenated nuclei were prevalent in the obese, diabetic nonalcoholics, of whom 47% had significant fibrosis and 8% cirrhosis, the latter present in 38% and 89% of ambulatory and hospitalized alcoholic hepatitis (P = 0.0001), respectively. In asymptomatic subjects with suspected liver disease, a liver biopsy is the only way of establishing the type and severity of liver lesions.