Wilson's disease. Update of a systemic disorder with protean manifestations

[Hyperpigmentation]

The key diagnostic tool for hyperpigmentation is histopathology, which may be accompanied by certain laboratory tests. Hyperpigmentation may result from excess melanin (hypermelanosis), cutaneous iron deposits (hemosiderosis), cutaneous carotene deposits (carotenoderma), or cutaneous deposits of a substance not normally found in the skin (dyschromia). The different types of hypermelanosis may be classified as either localised or generalised. The former generally correspond to skin tumours and may form a cutaneous expression of complex syndromes, which most notably include cardiac abnormalities, or to pigmented forms of inflammatory and/or infectious dermatoses. Diffuse hypermelanosis is frequently a sign of systemic disease, generally metabolic or endocrine disease, or else it may result from pharmaceutical therapy. Herein we review the various causes of hyperpigmentation and the corresponding therapy.

[Diagnostics of Wilson's disease]

Wilson's disease is a rare genetic but treatable metabolic disorder which has a favorable prognosis when diagnosed early and treated adequately. Therefore, knowledge of this rare clinical condition and a reliable diagnosis are indispensable. The diagnostic work-up is initiated in cases of unexplained acute or chronic liver disease and/or an extrapyramidal motor disturbance occurring mostly between the 5th and 45th years of life. Manifestations with initial symptoms have occasionally been observed at an age younger than 1 year and later than 70 years. Immediate biochemical and genetic examinations for early diagnosis are essential. Further test methods, such as liver and transcranial sonography, cerebral magnetic resonance imaging (MRI) and ¹⁸F-fluorodeoxyglucose positron emission tomography (¹⁸F-FDG-PET), ¹²³I-beta-CIT and ¹²³I-iodobenzamide (IBZM) single photon emission computed tomography (SPECT), electrophysiology as well as fine motor tests are unspecific but can be used to test for organ damage and for monitoring of progress. Immediate initiation of a therapy is required and justified on the basis of a confirmed diagnosis.

Classification and differential diagnosis of Wilson's disease

Wilson's disease is characterized by hepatic and extrapyramidal movement disorders (EPS) with variable manifestation primarily between age 5 and 45. This variability often makes an early diagnosis difficult. A classification defines different clinical variants of Wilson's disease, which enables classifying the current clinical findings and making an early tentative diagnosis. Until the unequivocal proof or an autosomal recessive disorder of the hepatic copper transporter ATP7B has been ruled out, differential diagnoses have to be examined. Laboratory-chemical parameters of copper metabolism can both be deviations from the norm not related to the disease as well as other copper metabolism disorders besides Wilson's disease. In addition to known diseases such as Menkes disease, occipital horn syndrome (OHS), Indian childhood cirrhosis (ICC) and ceruloplasmin deficiency, recently discovered disorders are taken into account. These include MEDNIK syndrome, Huppke-Brendel syndrome and CCS chaperone deficiency. Another main focus is on differential diagnoses of childhood icterus correlated with age and anaemia as well as disorders of the extrapyramidal motor system. The Kayser-Fleischer ring (KFR) is qualified as classical ophthalmologic manifestation. The recently described manganese storage disease presents another rare metabolic disorder with symptoms similar to Wilson's disease. As this overview shows, Wilson's disease fits into a broad spectrum of internal and neurological disease patterns with icterus, anaemia and EPS.

Is it possible to diagnose Wilson disease with a piece of skin?

Renal, skeletal, cardiac, and ophthalmic involvement in Wilson disease (WD) is well known. In this case report, high copper content and ultrastructural findings of skin of a patient with WD accompanied by xerosis are presented.

Dermatological signs in Wilson's disease

BACKGROUND

Because no data on skin and mucosal findings of patients with Wilson's disease have been published so far, the aim of the present study was to investigate the prevalence of mucosal and skin findings in childhood Wilson's disease and to determine its specific dermatological findings, if any exist.

METHODS

Thirty-seven 4-17-year-old children with Wilson's disease were included. A complete skin, scalp skin, mucous membrane and nail examination was performed.

RESULTS

Of the children, 26 (70.3%) had at least one dermatological finding. Twenty-five (67.6%), five (13.5%), nine (24.3%) had at least one skin, mucosal and nail finding, respectively. The most prevalent dermatological diagnosis of the Wilson's disease patients was xerosis (45.7%). The presence of dermatological findings was not related to drug usage, severity of the disease, or malnutrition. The duration of the disease was not different in patients with or without dermatological findings. The frequency of skin findings alone, however, was high in relatively newly diagnosed patients (<2 years).

CONCLUSION

Dermatologist should be aware of the various dermatological manifestations of Wilson's disease, because a careful and objective skin, mucosa, nail and hair examination may be indicative of a diagnosis of Wilson's disease, particularly in early cases.

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.

Evidence that translation reinitiation leads to a partially functional Menkes protein containing two copper-binding sites

Menkes disease (MD) is an X-linked recessive disorder of copper metabolism. It is caused by mutations in the ATP7A gene encoding a copper-translocating P-type ATPase, which contains six N-terminal copper-binding sites (CBS1-CBS6). Most patients die in early childhood. We investigated the functional effect of a large frameshift deletion in ATP7A (including exons 3 and 4) identified in a patient with MD with unexpectedly mild symptoms and long survival. The mutated transcript, ATP7A(Delta ex3+ex4), contains a premature termination codon after 46 codons. Although such transcripts are generally degraded by nonsense-mediated mRNA decay (NMD), it was established by real-time PCR quantification that the ATP7A(Delta ex3+ex4) transcript was protected from degradation. A combination of in vitro translation, recombinant expression, and immunocytochemical analysis provided evidence that the ATP7A(Delta ex3+ex4) transcript was protected from degradation because of reinitiation of protein translation. Our findings suggest that reinitiation takes place at two downstream internal codons. The putative N-terminally truncated proteins contain only CBS5 and CBS6. Cellular localization and copper-dependent trafficking of the major part of endogenous and recombinant ATP7A(Delta ex3+ex4) proteins were similar to the wild-type ATP7A protein. Furthermore, the ATP7A(Delta ex3+ex4) cDNA was able to rescue a yeast strain lacking the homologous gene, CCC2. In summary, we propose that reinitiation of the NMD-resistant ATP7A(Delta ex3+ex4) transcript leads to the synthesis of N-terminally truncated and at-least-partially functional Menkes proteins missing CBS1-CBS4. This finding--that a mutation that would have been assumed to be null is not--highlights the need to examine the biochemical phenotype of patients to deduce the efficacy of copper therapy.

Fuzzy classification by fuzzy labeled neural gas

We extend the neural gas for supervised fuzzy classification. In this way we are able to learn crisp as well as fuzzy clustering, given labeled data. Based on the neural gas cost function, we propose three different ways to incorporate the additional class information into the learning algorithm. We demonstrate the effect on the location of the prototypes and the classification accuracy. Further, we show that relevance learning can be easily included.

Living-related liver transplantation for Wilson's disease

Orthotopic liver transplantation has been applied to the treatment of Wilson's disease (WD), living-related liver transplantation (LRLT) has also been indicated for WD with increasing frequency. Between January 2001 and November 2003, 22 LRLTs were performed on patients (19 pediatric, three adults) with WD in liver transplantation center. Two patients were transplanted because of a presentation coexistent with fulminant hepatic failure. Twenty presented with chronic advanced liver disease with (n = 9) or without (n = 11) associated neurologic manifestations. All the recipients had low serum ceruloplasmin levels with a mean value of 12.8 +/- 3.2 mg/dl before transplantation and increased to an average of 26.0 +/- 3.6 mg/dl after LRLT at the latest evaluation. The survival patients with neurologic manifestations such as tremor, dysarthia, dysphagia, dystonia and sialorrhea had improved after LRLT. This suggests that LRLT not only resolves the hepatic but also ameliorates the neurologic consequences of WD.

Classification of fine-motoric disturbances in Wilson's disease using artificial neural networks

Patients suffering from Wilson's disease are divided into several types according clinical symptoms only at time of manifestation. Thereby two main subgroups exist: neurologic and non-neurologic types. After long-term therapy the neurological symptoms occurring in hepatolenticular degeneration may be improved but frequently with remaining fine-motoric disturbances which should be used for evaluation of the actual patient state. These disturbances are difficult to assess in an exact and objective manner by clinical examination. Therefore we measured fine-motoric passive and active abilities based on a standardized test set using the VSCOPE-system. The parallel evaluation of all fine-motoric data using an artificial neural network leads to a reclassification of these patients based on actual fine-motoric abilities but not reflecting the clinical classification at time of manifestation.

Klassifikation des Morbus Wilson auf der Basis neurophysiologischer Parameter

In addition to hepatolenticular degeneration in Wilson's disease, sensory and extrapyramidal motoric systems are also disturbed. In this study a classification on the basis of neurophysiological parameters (EAEP, VEP, MSEP, TSEP and MEP) was established according to subclinical disturbances of these pathways in patients with Wilson's disease on long-term treatment. A cluster analysis of latencies of these evoked potentials was performed. The results of cluster analysis revealed three types of electrophysiological profiles: type I with normal latencies and types II and III showing different patterns of prolonged latencies. However, there was no correlation between clinical classification and the results of cluster analysis based on the electrophysiological data. The neurophysiological based classification provides additional information about central manifestations and aids in characterizing the progress of the disease.

Rapid detection of mutations in Wilson disease gene ATP7B by DNA strip technology

Wilson disease leads to severe hepatic and neurological pathology resulting from cellular copper overload in the respective tissue. Although the affected gene, ATP7B, has been identified, genetic testing is challenging, time-consuming and expensive. Here we describe the development and use of a novel diagnostic test for four frequent mutations (M769V, W779X, H1069Q and P1134P-fs) found in Germany and many other countries in Europe. The test is based on multiplex polymerase chain reaction and DNA strip technology and was found to be highly sensitive and specific, as well as timely and cost-effective. We conclude that this test is a useful and reliable tool to screen Wilson disease patients and their family members for these mutations and may facilitate diagnosis in this complex disease.

[44-year-old patient with fulminant liver failure]

The 44-year old female patient was admitted with acute hepatic failure and extensive haemolysis under the preliminary diagnosis of Wilson's disease. General characteristic criteria of Wilson's disease as Kayser-Fleischer ring, low serum copper and low ceruloplasmin levels were not observed. The preliminary diagnosis of acute Wilson's disease was established on the basis of the characteristic laboratory values with an AP/bilirubin ratio <2, an AST/ALT ratio >4, accompanying hemolysis and a highly elevated cupruresis. The definitive diagnosis of Wilson's disease was verified after orthotopic liver transplantation by quantitative copper evaluation in the explanted liver. The case represents the yet oldest patient reported with an acute manifestation of Wilson's disease.

Liver transplantation for Wilson's disease: long-term results and quality-of-life assessment

BACKGROUND

Wilson's disease associated with severe liver disease is effectively cured by orthotopic liver transplantation (OLT). However, there are also anecdotal reports of improved or resolved neurologic symptoms after OLT in patients with stable or normal liver function. Side effects with conventional chelating agents are common, and it has been suggested that OLT should be considered in patients with severe progressive neurologic symptoms. However, the decision to apply this therapeutic modality to a subgroup of patients without significant liver disease is a quality-of-life issue.

METHODS

Long-term follow-up and quality-of-life data were obtained prospectively for 24 patients who underwent OLT between 1988 and 2000 for Wilson's disease associated with severe liver disease. In long-term survivors, quality of life was assessed using the 36-Item Short Form 36 Health Survey Questionnaire.

RESULTS

One patient who had multiorgan failure before OLT died within 24 hr of surgery and two patients died within 1 year because of immunosuppressant-related complications. There have been no deaths or graft loss in patients who have undergone transplantation since 1994, and after a median follow-up of 92 months, all survivors have satisfactory graft function (5-year patient and graft survival, 87.5%), with quality-of-life scores (assessed in 86% of survivors) comparable to age- and sex-matched controls from the general population.

CONCLUSIONS

The authors' results suggest that liver transplantation can be safely performed in patients with Wilson's disease, with excellent long-term results and quality of life. Further study of the utility of liver transplantation in the management of patients with severe neurologic symptoms is justified.

Activation of metallothioneins and alpha-crystallin/sHSPs in human lens epithelial cells by specific metals and the metal content of aging clear human lenses

PURPOSE

To identify those metallothionein and alpha-crystallin/small heat-shock genes induced by toxic metals in human lens cells and to evaluate the levels of these metals between young and aged human lenses.

METHODS

Human SRA01/04 and primary human lens epithelial cells were cultured and exposed to Cd(2+), Cu(2+), and Zn(2+). The levels of lens metallothioneins (Ig, If, Ih, Ie, and IIa) and alpha-crystallin/small heat-shock (alphaA-crystallin, alphaB-crystallin, and HSP27) genes were analyzed by semiquantitative and quantitative competitive RT-PCR. The content of aluminum, cadmium, calcium, chromium, copper, iron, lead, magnesium, manganese, nickel, potassium, sodium, and zinc in young (mean, 32.8 years), middle-aged (mean, 52.3 years), and old (mean, 70.5 years) human lenses was analyzed by inductively coupled plasma-emission spectroscopy.

RESULTS

Lens metallothioneins (Ig, If, Ih, Ie, and IIa) and alpha-crystallin/small heat-shock genes (alphaA-crystallin, alphaB-crystallin, and HSP27) were differentially induced by specific metals in SRA01/04 human lens epithelial cells. Cd(2+) and Zn(2+), but not Cu(2+), induced the metallothioneins, whereas Cd(2+) and Cu(2+), but not Zn(2+), induced alphaB-crystallin and HSP27. alphaA-crystallin was induced by Cu(2+) only. Similar responses of the metallothionein IIa gene were detected in identically treated primary human lens epithelial cells. Cd(2+) and Zn(2+) induced metallothionein IIa to five times higher levels than metallothionein Ig. Of 13 different metals, only iron was altered, exhibiting an 81% decrease in old versus young lenses.

CONCLUSIONS

Induction of metallothioneins and alpha-crystallin/small heat shock proteins by different metals indicates the presence of metal-specific lens regulatory pathways that are likely to be involved in protection against metal-associated stresses.

Diagnosis and treatment of Wilson's disease

Wilson's disease (WD) is an autosomal recessive disease that causes increased copper deposition in the liver and basal ganglia with resultant hepatic and neurologic sequelae. In the past few years, dramatic new discoveries have changed our understanding of the pathophysiology of WD. Although there are potentially life-saving therapies for WD, there is much controversy surrounding the optimal treatments of patients in the various stages of the disease. Specifically, the relative roles of penicillamine, trientene, and tetrathiomolybdate in the initial treatment of the symptomatic patient with WD remain to be defined. Zinc monotherapy for maintenance treatment and in the treatment of asymptomatic patients with WD is still controversial. It is also unclear whether neurologic status alone is an indication for liver transplantation in WD. This paper reviews the pathogenesis, genetics, clinical presentation, and diagnosis, with a special emphasis on the treatment controversies that arise in the care of the WD patient.

[Wilson's disease. Clinical presentation, treatment and evolution in 21 cases]

PURPOSE

Wilson's disease is characterized by neuropsychiatric symptoms with frequent extrapyramidal and intellectual presentations. They have an insidious evolution that leads to a late diagnosis and less therapeutic effectiveness in the advanced forms.

METHODS

We report 21 cases of Wilson's disease with neurological complications, emphasizing clinical semiology, diagnostic means and problems of the therapeutics in our country.

RESULTS

The average age at the beginning of the disease was 17.6 years, with a female prevalence (8/13). The signs at first were mostly all neurological (71.4%), then psychiatric (19%) or hepatic (19%). The most common neurological signs were dystonia of members (81%), dysarthria (76%), tremors (76%) or disorders of motoricity (71.4%). Sometimes there were sialorrhea or disorders of the handwriting. The Kayser-Fleischer ring was present in 19 patients. Eighteen patients had clinical and/or biological hepatic involvement. The diagnosis was confirmed by biochemical examinations, which found a low rate of copper in blood, a sinking rate of ceruloplasmin and a very high rate of urinary copper. The cerebral computer tomography shows a cortical and/or subcortical atrophy (37%), and/or a low density of the central grey cores (35%). The treatment was based on D-penicillamine and/or zinc sulfate, according to the availability of the drugs. The evolution was favourable among 18 patients (85%) and not good in 42.8% of the cases. Six of the first patients had poor evolution after many years of follow-up. Finally, only 12 patients (57%) had a very good outcome. The family investigation made among 17 patients revealed 13 family cases. The only predictive factor of a poor evolution was the therapeutic noncompliance (P = 0.006).

CONCLUSIONS

The neurological presentations are traditional during the Wilson's disease, but are often ignored. We must suspect the disease in children when faced with disorders of handwriting or school failures and in the adult, when faced with neurological symptoms in a patient having a hepatic disease. We must not hesitate to consider it even given purely psychiatric signs, and we had better know to seek the neurological ones.

Pyridoxal isonicotinoyl hydrazone (PIH) prevents copper-mediated in vitro free radical formation

Pyridoxal isonicotinoyl hydrazone (PIH) is an iron chelator with antioxidant activity, low toxicity and is useful in the experimental treatment of iron-overload diseases. Previous studies on x-ray diffraction have revealed that PIH also forms a complex with Cu(II). Since the main drug of choice for the treatment of Wilson's disease, d-penicillamine, causes a series of side effects, there is an urgent need for the development of alternative copper chelating agents for clinical use. These chelators must also have antioxidant activity because oxidative stress is associated with brain and liver copper-overload. In this work we tested the ability of PIH to prevent in vitro free radical formation mediated by Cu(II), ascorbate and dissolved O2. Degradation of 2-deoxyribose mediated by 10 microM Cu(II) and 3 mM ascorbate was fully inhibited by 10 microM PIH (I50 = 6 microM) or 20 microM d-penicillamine (I50 = 10 microM). The antioxidant efficiency of PIH remained unchanged with increasing concentrations (from 1 to 15 mM) of the hydroxyl radical detector molecule, 2-deoxyribose, indicating that PIH does not act as a hydroxyl scavenger. On the other hand, the efficiency of PIH (against copper-mediated 2-deoxyribose degradation and ascorbate oxidation) was inversely proportional to the Cu(II) concentration, suggesting a competition between PIH and ascorbate for complexation with Cu(lI). An almost full inhibitory effect by PIH was observed when the ratio PIH:copper was 1:1. A similar result was obtained with the measurement of copper plus ascorbate-mediated O2 uptake. Moreover, spectral studies of the copper and PIH interaction showed a peak at 455 nm and also indicated the formation of a stable Cu(II) complex with PIH with a 1:1 ratio. These data demonstrated that PIH prevents hydroxyl radical formation and oxidative damage to 2-deoxyribose by forming a complex with Cu(II) that is not reactive with ascorbate (first step of the reactions leading to hydroxyl radical formation from Cu(II), ascorbate and O2) and does not participate in Haber-Weiss reactions.

Copper transportion of WD protein in hepatocytes from Wilson disease patients in vitro

AIM

To study the effect of copper transporting P-type ATPase in copper metabolism of hepatocyte and pathogenesis of Wilson disease (WD).

METHODS

WD copper transporting properties in some organelles of the cultured hepatocytes were studied from WD patients and normal controls.These cultured hepatocytes were incubated in the media of copper 15 mg x L(-1) only, copper 15 mg x L(-1) with vincristine (agonist of P-type ATPase) 0.5mg x L(-1), or copper 15 mg x L(-1) with vanadate (antagonist of P-type ATPase) 18.39 mg x L(-1) separately. Microsome (endoplasmic reticulum and Golgi apparatus), lysosome, mitochondria, and cytosol were isolated by differential centrifugation. Copper contents in these organelles were measured with atomic absorption spectrophotometer, and the influence in copper transportion of these organelles by vanadate and vincristine were comparatively analyzed between WD patients and controls. WD copper transporting P-type ATPase was detected by SDS-PAGE in conjunction with Western blot in liver samples of WD patients and controls.

RESULTS

The specific WD proteins (M(r)155,000 lanes) were expressed in human hepatocytes, including the control and WD patients. After incubation with medium containing copper for 2 h or 24 h, the microsome copper concentration in WD patients was obviously lower than that of controls, and the addition of vanadate or vincristine would change the copper transporting of microsomes obviously. When incubated with vincristine, levels of copper in microsome were significantly increased, while incubated with vanadate, the copper concentrations in microsome were obviously decreased. The results indicated that there were WD proteins, the copper transportion P-type ATPase in the microsome of hepatocytes. WD patients possessed abnormal copper transporting function of WD protein in the microsome, and the agonist might correct the defect of copper transportion by promoting the activity of copper transportion P-type ATPase.

CONCLUSION

Copper transportion P-type ATPase plays an important role in hepatocytic copper metabolism. Dysfunction of hepatocytic WD protein copper transportion might be one of the most important factors for WD.

Haemolytic onset of Wilson disease in a patient with homozygous truncation of ATP7B at Arg1319

We describe a 19-year-old woman with haemolytic anaemia and thrombocytopenia as the initial manifestation of Wilson disease (WD). There are two reasons for reporting such an improbable case. First, it emphasizes the importance of recognizing atypical clinical presentations of potentially lethal recessive traits for which therapy is available. Second, it shows that, even in a monogenic disorder like WD, the phenotype cannot be extrapolated from the mutated genotype in a simple fashion; this patient had a relatively late-onset form of WD despite homozygosity for a genetic lesion leading to an apparent complete loss of function of the WD copper transporter.

Functional expression of the Wilson disease protein reveals mislocalization and impaired copper-dependent trafficking of the common H1069Q mutation

Wilson disease is an autosomal recessive disorder of hepatic copper metabolism caused by mutations in a gene encoding a copper-transporting P-type ATPase. To elucidate the function of the Wilson protein, wild-type and mutant Wilson cDNAs were expressed in a Menkes copper transporter-deficient mottled fibroblast cell line defective in copper export. Expression of the wild-type cDNA demonstrated trans-Golgi network localization and copper-dependent trafficking of the Wilson protein identical to previous observations for the endogenously expressed protein in hepatocytes. Furthermore, expression of the Wilson cDNA rescued the mottled phenotype as evidenced by a reduction in copper accumulation and restoration of cell viability. In contrast, expression of an H1069Q mutant Wilson cDNA did not rescue the mottled phenotype, and immunofluorescence studies showed that this mutant Wilson protein was localized in the endoplasmic reticulum. Consistent with these findings, pulse-chase analysis demonstrated a 5-fold decrease in the half-life of the H1069Q mutant as compared with the wild-type protein. Maintenance of these transfected cell lines at 28 degreesC resulted in localization of the H1069Q protein in the trans-Golgi network, suggesting that a temperature-sensitive defect in protein folding followed by degradation constitutes the molecular basis of Wilson disease in patients harboring the H1069Q mutation. Taken together, these studies describe a tractable expression system for elucidating the function and localization of the copper-transporting ATPases in mammalian cells and provide compelling evidence that the Wilson protein can functionally substitute for the Menkes protein, supporting the concept that these proteins use common biochemical mechanisms to effect cellular copper homeostasis.