INITIAL ASSESSMENT FINDINGS IN PATIENTS WITH CONFIRMED WILSON’S DISEASE

Bacground. The optimization of Wilson’s disease (WD) diagnosis is one of the most disputable problem. Objective. The retrospective study of initial assessment findings under clinical suspicion for WD in 102 patients with the confirmed diagnosis. Material and methods. The results of laboratory tests and Kaiser-Fleischer rings (KF rings) identification under clinical suspicion for WD in 102 patients with the confirmed diagnosis. Results. At stage I, 17 patients (16.7%; 95% CI 10.7–25.1) were defined as having clinically definitive WD based on the combination of low serum ceruloplasmin and KF rings, 4 patients (3.9%; 95% CI 1.5–9.7) – based on the drop of ceruloplasmin level. After stage II, involving 24-hour urinary copper excretion evaluation, the rate of definitive diagnosis of WD reached 24,5% (95% CI 17.2 33.7). After stage III (genotyping for carriage of ATP7B gene mutations) – 56.9% (95% CI 47.2–66.0). Serum free copper increase was found in 54.9% (95% CI 41.4 67.7) of cases. Conclusions. Under clinical suspicion for WD, initial structured ophthalmological, laboratory and molecular-genetic assessment ensured the diagnosis of WD only in 56.9% (95% CI 56.9; 47.2–66.1). Frequent detection of serum free copper increase (54.9%, 95% CI 41.4 67.7) allows to use this test due to its greater availability as compared with 24-hour urinary copper excretion evaluation in WD diagnostics.

Value of Kayser-Fleischer ring as a diagnostic tool for Wilson’s disease in children

The Kayser-Fleischer(K-F) ring is the hallmark of Wilson’s disease (WD). In most adults or older children, the diagnosis of Wilson’s disease may be made easily when K-Frings and low ceruloplasmin levels are present. In this study presence of K-F ring has been evaluated among children with liver disease in Bangladesh to improve the management of Chronic liver disease due to WD and reduce complications. This cross-sectional study was carried out at the Department of Paediatric Gastroenterology and Nutrition, BSMMU, Dhaka on 60 children presented with liver disease. Thirty children over three years of age considered as cases (Group-I) and thirty children with non- Wilsonian liver disease as control (Group-II). Slit lamp examination for K-F ring and twenty-four hour urinary copper excretion after giving one gram d-penicillamine 12-hour apart were done in each patient. The efficacy of K-F ring was studied. Mean age of WD patients was 8.9± 2.78 years, with a male female ratio of 1.3: 1. There was significant low level of serum ceruloplasmin in 93.33% of cases (p<.001). After penicillamine challenge, 24-hour urinary copper excretion was found significantly higher in patients with WD (median 3626.5±1698 μg/24h, range 1262- 195000) than non-Wilsonian liver disease (median 450±278.09 μg/24-h, range 47- 2062 μg/24h), (p<.001). K-F ring was found in 15 (50%) patients, absent in all patients of non-Wilsonian liver disease group and the difference was statistically significant (p<.001). Evaluation of Kayser-Fleischer ring is still a very essential diagnostic tool and is a non-invasive, affordable way to assist in the diagnosis of a potentially fatal disease.

Regulation of murine copper homeostasis by members of the COMMD protein family

ABSTRACTCopper is an essential transition metal for all eukaryotes. In mammals, intestinal copper absorption is mediated by the ATP7A copper transporter, whereas copper excretion occurs predominantly through the biliary route and is mediated by the paralog ATP7B. Both transporters have been shown to be recycled actively between the endosomal network and the plasma membrane by a molecular machinery known as the COMMD/CCDC22/CCDC93 or CCC complex. In fact, mutations in COMMD1 can lead to impaired biliary copper excretion and liver pathology in dogs and in mice with liver-specific Commd1 deficiency, recapitulating aspects of this phenotype. Nonetheless, the role of the CCC complex in intestinal copper absorption in vivo has not been studied, and the potential redundancy of various COMMD family members has not been tested. In this study, we examined copper homeostasis in enterocyte-specific and hepatocyte-specific COMMD gene-deficient mice. We found that, in contrast to effects in cell lines in culture, COMMD protein deficiency induced minimal changes in ATP7A in enterocytes and did not lead to altered copper levels under low- or high-copper diets, suggesting that regulation of ATP7A in enterocytes is not of physiological consequence. By contrast, deficiency of any of three COMMD genes (Commd1, Commd6 or Commd9) resulted in hepatic copper accumulation under high-copper diets. We found that each of these deficiencies caused destabilization of the entire CCC complex and suggest that this might explain their shared phenotype. Overall, we conclude that the CCC complex plays an important role in ATP7B endosomal recycling and function.

Inherited diseases of copper metabolism: Wilson’s disease and Menkes’ disease

Copper is an essential metal that is an important cofactor for many proteins and enzymes. Two related genetic defects in copper transport have been described, each with distinct phenotypes. Wilson’s disease—an uncommon disorder (1 in 30 000) caused by autosomal recessive loss-of-function mutations in a metal-transporting P-type ATPase (ATP7B) that result in defective copper excretion into bile and hence copper toxicity. Typical presentation is in the second and third decade of life with liver disease (ranging from asymptomatic to acute fulminant hepatic failure or chronic end-stage liver disease) or neurological or psychiatric disorder (dystonia, dysarthria, parkinsonian tremor, movement disorder, a spectrum of psychiatric ailments). While no single biochemical test or clinical finding is sufficient for establishing the diagnosis, typical findings include low serum ceruloplasmin, high urinary copper excretion, and elevated liver copper content. Corneal Kayser–Fleischer rings may be seen. Treatment is with copper chelating agents and zinc. Liver transplantation is required for fulminant hepatic failure and decompensated liver disease unresponsive to medical therapy. Menkes’ disease—a rare disorder (1 in 300 000) caused by X-linked loss-of-function mutations in a P-type ATPase homologous to ATP7B (ATP7A) that result in defective copper transport across intestine, placenta, and brain and hence cellular copper deficiency. Clinical presentation is in infancy with facial dimorphism, connective tissue disorder, hypopigmentation, abnormal hair, seizures, and failure to thrive, usually followed by death by age 3 years (although some variants with a milder phenotype result from milder mutations, e.g. occipital horn syndrome). Treatment, which is only effective when presymptomatic diagnosis is made in a sibling after florid presentation in a previous affected sibling, is with intravenous copper histidine.

Reference intervals of spot urine copper excretion in preschool children and potential application in pre-symptomatic screening of Wilson’s disease

ABSTRACTBackgroundWith spot urine collected from a large control sample of preschool children (aged 3-7 years), reference range of spot urine copper excretion indexes and their biological variation were defined.MethodsIn order to investigate their test performance in screening of Wilson disease in this age group, multiple spot urine samples from 6 WD patients diagnosed at presymptomatic stage were analysed. Cut-off values for spot urine copper concentration, copper to creatinine ratio and copper to osmolality ratio at 0.5 µmol/L, 0.1 µmol/mmol and 0.00085 µmol/mOsmol (32 µg/L, 56 µg/g creatinine and 0.054 µg/mOsmol, respectively, in conventional units) have potential application in differentiation of WD patients.ResultsThe data provides a new insight that the inter-individual variation of spot urine copper indexes (CVg) were moderate with figures around 60% which was similar to other clinically useful urine tests, such as urine albumin excretion ratio. Spot urine copper excretion strongly correlated with both urine creatinine and osmolality. And more than 95% of data points in health preschool children fell within prediction regions by linear regression suggesting a good utility of normalisation by these 2 analytes. Receiver operator curve (ROC) showed that copper to osmolality ratio was the best index with an area under curve (AUC) greater than 0.98.ConclusionsBased on the data, a new WD screening time window targeting preschool children is proposed. Application of a bivariate screening strategy using spot urine copper concentration and urine osmolality may be useful in a population screening program for preschool children.

Biochemical markers for the diagnosis and monitoring of Wilson Disease

Wilson disease (WD) is an autosomal recessively-inherited disorder of copper metabolism and characterised by a pathological accumulation of copper. The ATP7B gene encodes for a transmembrane copper transporter essential for biliary copper excretion. Depending on time of diagnosis, severity of disease can vary widely. Almost all patients show evidence of progressive liver disease. Neurological impairments or psychiatric symptoms are common in WD patients not diagnosed during adolescence. WD is a treatable disorder, and early treatment can prevent the development of symptoms in patients diagnosed while still asymptomatic. This is why the early diagnosis of WD is crucial. The diagnosis is based on clinical symptoms, abnormal measures of copper metabolism and DNA analysis. Available treatment includes chelators and zinc salts which increase copper excretion and reduce copper uptake. In severe cases, liver transplantation is indicated and accomplishes a phenotypic correction of the hepatic gene defect. Recently, clinical development of the new copper modulating agent tetrathiomolybdate has started and direct genetic therapies are being tested in animal models. The following review focuses especially on biochemical markers and how they can be utilised in diagnosis and drug monitoring.