Wilson's disease

Role of serum ceruloplasmin in the diagnosis of Wilson's disease: A large Chinese study

Background

Conventionally, serum ceruloplasmin levels below the lower reference limit (0. 20 g/L) is considered a diagnostic cutoff point for Wilson's disease (WD). However, the lower reference limit varies with assay methodologies and the individuals in the included studies. The objective of this study was to determine the optimal cutoff value of serum ceruloplasmin levels for the diagnosis of WD in a large Chinese cohort and to identify factors associated with serum ceruloplasmin.

Methods

The cutoff value of ceruloplasmin levels was developed based on a retrospective derivation cohort of 3,548 subjects (1,278 patients with WD and 2,270 controls) and was validated in a separate validation cohort of 313 subjects (203 patients with WD and 110 controls). The performance of immunoassay was tested by receiver operating characteristic curve (ROC) analysis, and differences among the groups were analyzed by using the Mann-Whitney U-test and the Kruskal-Wallis test.

Results

The conventional cutoff of serum ceruloplasmin levels of <0.2 g/L had an accuracy of 81.9%, which led to a false-positive rate of 30.5%. The optimal cutoff of the serum ceruloplasmin level for separating patients with WD from other participants was 0.13 g/L, as determined by ROC analysis. This cutoff value had the highest AUC value (0.99), a sensitivity of 97.0%, and a specificity of 96.1%. Moreover, it prevented unnecessary further investigations and treatments for 492 false-positive patients. By determining the correlation between serum ceruloplasmin and phenotypes/genotypes in patients with WD, we found that the serum ceruloplasmin level was lower in early-onset patients and higher in late-onset patients. Interestingly, patients with the R778L/R919G genotype had higher serum ceruloplasmin levels than patients with other hot spot mutation combinations.

Conclusion

Our work determined the optimal cutoff value of serum ceruloplasmin levels for the diagnosis of WD and identified differences in serum ceruloplasmin levels with respect to the age of symptom onset and ATP7B mutations, which may provide some valuable insights into the diagnosis and counsel of patients with WD.

Copper-Induced Epigenetic Changes Shape the Clinical Phenotype in Wilson's Disease

Wilson's disease is a congenital disorder of copper metabolism whose pathogenesis remains, at least in part, unknown. Subjects carrying the same genotype may show completely different phenotypes, differing for the age at illness onset or for the hepatic, neurologic or psychiatric clinical presentation. The inability to find a unequivocal correlation between the type of mutation in the ATPase copper transporting beta (ATP7B) gene and the phenotypic manifestation, has encouraged many authors to look for epigenetic factors interacting with the genetic changes. Here, the evidences regarding the ability of copper overload to change the global DNA methylation status are discussed.

Liver pathology in Wilson's disease: From copper overload to cirrhosis

Wilson's disease (WD) is a genetic metabolic disease strictly associated with liver cirrhosis. In this review, the genetic bases of the disease are discussed, with emphasis on the role of ATP7B (the Wilson disease protein) dysfunction as a determinant factor of systemic copper overload. Regarding the different multiple mutations described in WD patients, the peculiarity of Sardinian population is highlighted, Sardinians carrying a rare deletion in the promoter (5' UTR) of the WD gene. The role of epigenetic changes in the clinical presentation and evolution of liver disease in WD patients is also discussed, nutrition probably representing a relevantly risk factor in WD patients. The role of transmission electron microscopy in the diagnosis of WD-related liver disease is underlined. Mitochondrial changes, increased peroxisomes fat droplets, lipolysosomes and intranuclear glycogen inclusions are reported as the most frequent ultrastructural changes in the liver of WD carriers. The role of histochemical stains for copper is analyzed, and the Timm's method is suggested as the most sensitive one for revealing hepatic copper overload in all stage of WD. The marked variability of the histological liver changes occurring in WD is underlined simple steatosis may represent the only pathological changes, frequently associated with glycogenated nuclei. Mallory-Denk bodies lipogranulomas alcoholic and non-alcoholic fatty liver disease ending with bridging fibrosis and cirrhosis. Finally, the reversal of fibrosis as a possible therapeutic objective in WD is discussed.

Wilson's disease with hepatic manifestations as the first presentation: An analysis of 93 cases

AIM: To analyze the clinical data for patients with Wilson's disease with hepatic manifestations as the first presentation to provide a reference for the diagnosis of this disease.

METHODS: The clinical data for 93 patients with Wilson's disease with hepatic manifestations as the first presentation, who were treated at our hospital from January 1993 to April 2010, were reviewed retrospectively.

RESULTS: The age of onset ranged from 4 to 49 years. The average course before achieving a definite diagnosis was 17.48 mo. Main first symptoms were jaundice (47.31%), fatigue (39.78%), and nausea and vomiting (37.63%). Main clinical presentation was cirrhosis. The positive rate of corneal K-F ring was 91.67%. The rate of abnormal urinary copper was 84.48%, and serum ceruloplasmin was abnormal in 81.40% of cases. Varying degrees of abnormality of liver function and blood coagulation were also observed. The percentage of patients showing abnormal liver and spleen ultrasound manifestations was 97.37%. The misdiagnosis rate was 61.29%.

CONCLUSION: Patients who are suspected to have Wilson's disease with hepatic manifestations as the first presentation should undergo timely determination of K-F ring, 24-h urinary copper, serum ceruloplasmin, and abdominal ultrasound to improve early diagnosis, treatment, prognosis, and reduce misdiagnosis.

Alagille syndrome and Wilson disease in siblings: a diagnostic conundrum

The authors describe two siblings, each with a different, rare genetic condition that affects liver function. The index case, the 18-year-old asymptomatic brother of a young man recently diagnosed with Wilson disease, presented for Wilson disease screening and was also found to have abnormal liver function suggestive of cholestasis. However, ceruloplasmin level, 24 h urine copper concentration and liver synthetic function were normal. Further hepatic investigations and genetic mutation analysis were performed, ultimately leading to a diagnosis of Alagille syndrome. He was treated with ursodiol, which resulted in normalization of his liver function tests. Subsequently, he was found to be a carrier for a mutation in the Wilson disease gene, ATP7B. In the present report, the potential implications of being a heterozygote for Wilson disease in the context of Alagille syndrome are discussed. Also stressed is that care must be exercised by the clinician when diagnosing family members who may present with two different disorders closely mimicking one another.

Liver mitochondrial membrane crosslinking and destruction in a rat model of Wilson disease

Wilson disease (WD) is a rare hereditary condition that is caused by a genetic defect in the copper-transporting ATPase ATP7B that results in hepatic copper accumulation and lethal liver failure. The present study focuses on the structural mitochondrial alterations that precede clinical symptoms in the livers of rats lacking Atp7b, an animal model for WD. Liver mitochondria from these Atp7b–/– rats contained enlarged cristae and widened intermembrane spaces, which coincided with a massive mitochondrial accumulation of copper. These changes, however, preceded detectable deficits in oxidative phosphorylation and biochemical signs of oxidative damage, suggesting that the ultrastructural modifications were not the result of oxidative stress imposed by copper- dependent Fenton chemistry. In a cell-free system containing a reducing dithiol agent, isolated mitochondria exposed to copper underwent modifications that were closely related to those observed in vivo. In this cell-free system, copper induced thiol modifications of three abundant mitochondrial membrane proteins, and this correlated with reversible intramitochondrial membrane crosslinking, which was also observed in liver mitochondria from Atp7b–/– rats. In vivo, copper-chelating agents reversed mitochondrial accumulation of copper, as well as signs of intra-mitochondrial membrane crosslinking, thereby preserving the functional and structural integrity of mitochondria. Together, these findings suggest that the mitochondrion constitutes a pivotal target of copper in WD.

Hepatocellular carcinoma in a case of Wilson's disease treated with radiofrequency ablation therapy

A 37-year-old Japanese man was diagnosed with liver cirrhosis due to Wilson's disease in 2001 and treated with D-penicillamine. Thereafter, he was admitted to our hospital for further examination of a space occupying lesion in the liver. The patient was diagnosed with hepatocellular carcinoma (HCC) (7th segment, 2.5 cm in diameter) in May 2010 and treated with radiofrequency ablation therapy. Biopsy findings from a non-cancerous area revealed a fatty liver, though cirrhotic nodules were not found. Long-term treatment for Wilson's disease may improve hepatic fibrosis, and careful screening for HCC by abdominal imaging is needed in such cases.

Transplantation of a fetal liver cell-loaded hyaluronic acid sponge onto the mesentery recovers a Wilson's disease model rat

An auxiliary liver represents a promising alternative for liver transplantation. The use of a large amount of mature hepatocytes, however, despite their high function, is limited in a clinical setting. Here, we propose a novel transplantation system that dramatically improved a diseased animal by incorporating fetal liver cells (FLCs) as a cell source, the mesentery as a transplantation site and a hyaluronic acid (HA) sponge as a cell scaffold. We transplanted wild-type Long Evans Agouti rat FLCs embedded in HA sponges onto the mesentery of Long Evans Cinnamon (LEC) rats, an animal model for Wilson's disease. The FLC-loaded HA sponges successfully grafted and consequently prevented jaundice. Accordingly, the treated animals showed a significant reduction in blood copper concentration, which consequently led to significant decreases in serum total bilirubin and direct bilirubin, and to a significant increase in albumin productivity. Furthermore, haematoxylin and eosin staining of the host livers demonstrated that fibrosis at the periportal area was moderated in the treated animals. In conclusion, we transplanted FLC-loaded HA sponges onto the mesenteric blood vessels, leading to thick, liver-like tissue possessing blood vessels, and the liver tissue engineered thus exhibited a remarkable therapeutic effect on the copper metabolism deficiency of LEC rats.

Swallowing dysfunction in Wilson's disease: a scintigraphic study

Although dysphagia is a common complaint of patients with Wilson's disease (WD) and pneumonia is an important cause of death in these patients, swallowing function remains an underinvestigated field in this condition. The aim of this study was to characterize swallowing dynamics in WD patients. Eight WD patients and 15 age-matched controls underwent scintigraphic evaluation of oral and pharyngeal deglutition. Patients had significantly slower oral transit (P = 0.008) and a greater percentage of oral residue (P = 0.006) when compared to controls. Two of eight patients were free of neurological symptoms at time of examination. Impaired oropharyngeal function was found in patients without dysphagia and without neurological symptoms. Our findings indicate that WD may present with objective swallowing dysfunction, even in the absence of neurological manifestations. Further studies are necessary to investigate the impact of this dysfunction on morbidity and mortality in WD.

Abnormal hepatobiliary and circulating lipid metabolism in the Long-Evans Cinnamon rat model of Wilson's disease

Long-Evans Cinnamon (LEC) rats exhibit a genetic defect in Atp7b gene, which is homologous to the human Wilson's disease gene, resulting in an inability to mobilize copper from the liver. This study was undertaken to gain insight into the relationship between liver copper accumulation and plasma lipid profile, circulating lipoprotein composition, hepatic sterol metabolism and biliary lipid secretion rates in 12-week-old LEC rats compared to control Long-Evans rats. Concomitant with hepatic copper deposition, LEC rats displayed increased content of triglycerides (TGs), free cholesterol (FC) and cholesteryl ester (CE) in the liver. Hepatic concentrations of malondialdehyde (MDA), an index of lipid peroxidation were also significantly elevated in LEC rats (50%). This steatosis was associated with aberrant microsomal apolipoprotein (apo) B-100 and microsomal triglyceride transfer protein (MTP) content, hypotriglyceridemia, hypocholesterolemia and abnormalities in both circulating lipoprotein composition and size. Atypical hepatobiliary sterol metabolism was established by the assessment of the activity of key intracellular enzymes for cholesterol homeostasis, which demonstrated, with respect to controls, a 40% reduction in 3-hydroxy-3-methylglutaryl coenzyme A reductase, a 30% reduction in cholesterol 7alpha-hydroxylase, and a 54% reduction in acyl CoA:cholesterol acyltransferase. During a 6-h biliary drainage, a decline in the bile acid output was recorded and might be linked to the low protein expression of the bile salt export pump (BSEP or ABCB11). Our data emphasize the crucial role of copper balance in hepatic sterol homeostasis and lipoprotein metabolism in LEC rats. Additional studies are needed to delineate the mechanisms of these disorders.

Late onset of Wilson's disease in a family with genetic haemochromatosis

We report the coexistence of Wilson's disease and genetic haemochromatosis in one family. The diagnosis of genetic haemochromatosis was established in a 52-year-old man. Among his siblings, one 57-year-old sister and one 55-year-old brother had decreased copper and ceruloplasmin levels in serum and increased urinary copper excretion. The sister shared the same human leucocyte antigen haplotypes and was homozygous for the HFE mutation C282Y, like the propositus. However, she had normal liver iron content and increased liver copper content. Her dietary copper intake was probably excessive. The association of Wilson's disease and genetic haemochromatosis is rare and has only been described twice. The onset of Wilson's disease after 50 years of age is rare; Wilson's disease should be considered in any patient with unexplained chronic liver disease; an excess in liver copper content might be induced by excessive dietary input in a susceptible individual.

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Metabolic liver disease in the young adult

This chapter describes the gene mutations, phenotypes, diagnosis and therapy of the common metabolic liver diseases in young adulthood: haemochromatosis, Wilson disease, alpha(1)-anti-trypsin deficiency and cystic fibrosis. The remarkable variability of the phenotypical expression of the mutated genotypes makes screening recommendations and the establishment of prognosis for these liver disorders in young adults problematical. The diagnosis and therapy of the young adult with metabolic liver disease is discussed, with an emphasis on maintaining quality-of-life and balancing the importance of early intervention with the stigmatization of the diagnosis of potentially life-threatening liver disease. There is a critical need for the development of biochemical markers that would predict the risk of expression of clinical phenotypes and prognosis.

Hepatocellular carcinoma: predisposing conditions and precursor lesions

The global incidence of HCC is rising; in the United States, its rise is in parallel to that of cirrhosis due to the HCV and obesity epidemics. The lack of adequate treatment for advanced HCC mandates both prevention and early detection of these lesions. The limitations of currently available histopathologic evaluations, serologic markers, and radiographic imaging modalities in detecting HCC and its precursors have been outlined in this review. Refinements of all of these may lead to better HCC detection, earlier intervention, and successful treatment. Randomized controlled trials are necessary to evaluate the most efficacious and cost-effective approach to screening.