CSF copper concentration: a new parameter for diagnosis and monitoring therapy of Wilson's disease with cerebral manifestation

Distribution of non-ceruloplasmin-bound copper after i.v. 64Cu injection studied with PET/CT in patients with Wilson disease

Background & Aims

In Wilson disease (WD), copper accumulation and increased non-ceruloplasmin-bound copper in plasma lead to liver and brain pathology. To better understand the fate of non-ceruloplasmin-bound copper, we used PET/CT to examine the whole-body distribution of intravenously injected 64-copper (64Cu).

Methods

Eight patients with WD, five heterozygotes, and nine healthy controls were examined by dynamic PET/CT for 90 min and static PET/CT up to 20 h after injection. We measured 64Cu activity in blood and tissue and quantified the kinetics by compartmental analysis.

Results

Initially, a large fraction of injected 64Cu was distributed to extrahepatic tissues, especially skeletal muscle. Thus, across groups, extrahepatic tissues accounted for 45-58% of the injected dose (%ID) after 10 min, and 45-55% after 1 h. Kinetic analysis showed rapid exchange of 64Cu between blood and muscle as well as adipose tissue, with 64Cu retention in a secondary compartment, possibly mitochondria. This way, muscle and adipose tissue may protect the brain from spikes in non-ceruloplasmin-bound copper. Tiny amounts of cerebral 64Cu were detected (0.2%ID after 90 min and 0.3%ID after 6 h), suggesting tight control of cerebral copper in accordance with a cerebral clearance that is 2-3-fold lower than in muscle. Compared to controls, patients with WD accumulated more hepatic copper 6-20 h after injection, and also renal copper at 6 h.

Conclusion

Non-ceruloplasmin-bound copper is initially distributed into a number of tissues before being redistributed slowly to the eliminating organ, the liver. Cerebral uptake of copper is extremely slow and likely highly regulated. Our findings provide new insights into the mechanisms of copper control.

Impact and implications

Maintaining non-ceruloplasmin-bound copper within the normal range is an important treatment goal in WD as this "free" copper is considered toxic to the liver and brain. We found that intravenously injected non-ceruloplasmin-bound copper quickly distributed to a number of tissues, especially skeletal muscle, subcutaneous fat, and the liver, while uptake into the brain was slow. This study offers new insights into the mechanisms of copper control, which may encourage further research into potential new treatment targets.

Clinical trial number

2016-001975-59.

Neurological worsening in Wilson disease - clinical classification and outcome

BACKGROUND & AIMS

Prevention of neurological worsening (NW) under therapy is an unmet need in the management of Wilson disease (WD). In this study, we aimed to characterize the occurrence, associated outcomes and potential reversibility of NW in WD.

METHODS

From a total cohort of 457 patients with WD, 128 patients with WD and neurological features at any time point (all Caucasian, 63 females, median age at diagnosis 22 years) were identified by chart review at University Hospital Heidelberg and grouped according to initial presentation. The timing and occurrence of NW was assessed following a structured clinical examination during clinical visits.

RESULTS

Early NW (within the first 3 months of therapy) was observed in 30 out of 115 (26.1%) patients with neurological or mixed presentation and never in patients with a purely hepatic or asymptomatic presentation (0%). Late NW (after >12 months) was seen in a further 23 (20%) with neurological or mixed presentation and in 13 out of 294 (4.4%) patients with a hepatic or asymptomatic presentation. The median time from start of treatment to late NW was 20 months. Only three patients experienced NW between 3 and 12 months. NW was observed with D-penicillamine, trientine and zinc therapy and was reversible in 15/30 (50%) with early NW and in 29/36 (81%) with late NW.

CONCLUSIONS

In this study, we identified two peaks in NW: an early (≤3 months) treatment-associated peak and a late (>12 months of treatment) adherence-associated peak. Early paradoxical NW was attributed to treatment initiation and pre-existing neurological damage, and was not observed in those with a hepatic or asymptomatic presentation. Late NW is likely to be associated with non-adherence.

IMPACT AND IMPLICATIONS

In patients with Wilson disease, defined as an excess accumulation of copper which can damage the liver, brain and other vital organs, neurological worsening can occur despite chelation therapy. The study identifies different patterns of 'early' (<3 months) vs. 'late' (>12 months) neurological worsening in relation to initiation of chelation therapy and establishes possible causes and the potential for reversibility. These data should be useful for counseling patients and for guiding the optimal management of chelation therapy.

Investigation and management of Wilson's disease: a practical guide from the British Association for the Study of the Liver

Wilson's disease is an autosomal-recessive disorder of copper metabolism with hepatic, neurological, psychiatric, ophthalmological, haematological, renal, and rheumatological manifestations. Making a diagnosis can be challenging given that no single test can confirm or exclude the disease, and diagnostic delays are common. Treatment protocols vary and adverse effects, including paradoxical neurological worsening, can occur. In this Review, we provide a practical guide to the diagnosis of Wilson's disease. We include recommendations on indications for testing, how to interpret results, and when additional investigations are required. We also cover treatment initiation, ideally under the guidance of a specialist centre for Wilson's disease, and the principles behind long-term management. This guidance was developed by a multidisciplinary group of Wilson's disease experts formed through the British Association for the Study of the Liver. The guidance has been endorsed by the British Society of Gastroenterology and approved by the Association of British Neurologists.

Neurologic impairment in Wilson disease

Neurologic symptoms in Wilson disease (WD) appear at an older age compared to hepatic symptoms and manifest in patients with misdiagnosed liver disease, in patients when the hepatic stage is clinically silent, in the case of non-compliance with anti-copper treatment, or with treatment failure. Neurologic symptoms in WD are caused by nervous tissue damage that is primarily a consequence of extrahepatic copper toxicity. Copper levels in brain tissues as well as cerebrospinal fluid (CSF) are diffusely increased by a factor of 10 and its toxicity involves various mechanisms such as mitochondrial toxicity, oxidative stress, cell membrane damage, crosslinking of DNA, and inhibition of enzymes. Excess copper is initially taken-up and buffered by astrocytes and oligodendrocytes but ultimately causes dysfunction of blood-brain-barrier and demyelination. Most severe neuropathologic abnormalities, including tissue rarefaction, reactive astrogliosis, myelin palor, and presence of iron-laden macrophages, are typically present in the putamen while other basal ganglia, thalami, and brainstem are usually less affected. The most common neurologic symptoms of WD are movement disorders including tremor, dystonia, parkinsonism, ataxia and chorea which are associated with dysphagia, dysarthria and drooling. Patients usually manifest with various combinations of these symptoms while purely monosymptomatic presentation is rare. Neurologic symptoms are largely reversible with anti-copper treatment, but a significant number of patients are left with residual impairment. The approach for symptomatic treatment in WD is based on guidelines for management of common movement disorders. The vast majority of WD patients with neurologic symptoms have abnormalities on brain magnetic resonance imaging (MRI). Pathologic MRI changes include T2 hyperintensities in the basal ganglia, thalami and white matter, T2 hypointensities in the basal ganglia, and atrophy. Most importantly, brain damage and neurologic symptoms can be prevented with an early initiation of anti-copper treatment. Introducing population WD screening, e.g., by exome sequencing genetic methods, would allow early treatment and decrease the neurologic burden of WD.

The Potential of Bone Marrow Stem Cells to Correct Liver Dysfunction in a Mouse Model of Wilson's Disease

Metabolic liver diseases are excellent targets for correction using novel stem cell, hepatocyte, and gene therapies. In this study, the use of bone marrow stem cell transplantation to correct liver disease in the toxic milk (tx) mouse, a murine model for Wilson's disease, was evaluated. Preconditioning with sublethal irradiation, dietary copper loading, and the influence of cell transplantation sites were assessed. Recipient tx mice were sublethally irradiated (4 Gy) prior to transplantation with bone marrow stem cells harvested from normal congenic (DL) littermates. Of 46 transplanted tx mice, 11 demonstrated genotypic repopulation in the liver. Sublethal irradiation was found to be essential for donor cell engraftment and liver repopulation. Dietary copper loading did not improve cell engraftment and repopulation results. Both intravenously and intrasplenically transplanted cells produced similar repopulation successes. Direct evidence of functionality and disease correction following liver repopulation was observed in the 11 mice where liver copper levels were significantly reduced when compared with mice with no liver repopulation. The reversal of copper loading with bone marrow cells is similar to the level of correction seen when normal congenic liver cells are used. Transplantation of bone marrow cells partially corrects the metabolic phenotype in a mouse model for Wilson's disease.

Targeting copper in cancer therapy: 'Copper That Cancer'

Copper is an essential micronutrient involved in fundamental life processes that are conserved throughout all forms of life. The ability of copper to catalyze oxidation-reduction (redox) reactions, which can inadvertently lead to the production of reactive oxygen species (ROS), necessitates the tight homeostatic regulation of copper within the body. Many cancer types exhibit increased intratumoral copper and/or altered systemic copper distribution. The realization that copper serves as a limiting factor for multiple aspects of tumor progression, including growth, angiogenesis and metastasis, has prompted the development of copper-specific chelators as therapies to inhibit these processes. Another therapeutic approach utilizes specific ionophores that deliver copper to cells to increase intracellular copper levels. The therapeutic window between normal and cancerous cells when intracellular copper is forcibly increased, is the premise for the development of copper-ionophores endowed with anticancer properties. Also under investigation is the use of copper to replace platinum in coordination complexes currently used as mainstream chemotherapies. In comparison to platinum-based drugs, these promising copper coordination complexes may be more potent anticancer agents, with reduced toxicity toward normal cells and they may potentially circumvent the chemoresistance associated with recurrent platinum treatment. In addition, cancerous cells can adapt their copper homeostatic mechanisms to acquire resistance to conventional platinum-based drugs and certain copper coordination complexes can re-sensitize cancer cells to these drugs. This review will outline the biological importance of copper and copper homeostasis in mammalian cells, followed by a discussion of our current understanding of copper dysregulation in cancer, and the recent therapeutic advances using copper coordination complexes as anticancer agents.

The neurotoxicity of iron, copper and manganese in Parkinson's and Wilson's diseases

Impaired cellular homeostasis of metals, particularly of Cu, Fe and Mn may trigger neurodegeneration through various mechanisms, notably induction of oxidative stress, promotion of α-synuclein aggregation and fibril formation, activation of microglial cells leading to inflammation and impaired production of metalloproteins. In this article we review available studies concerning Fe, Cu and Mn in Parkinson's disease and Wilson's disease. In Parkinson's disease local dysregulation of iron metabolism in the substantia nigra (SN) seems to be related to neurodegeneration with an increase in SN iron concentration, accompanied by decreased SN Cu and ceruloplasmin concentrations and increased free Cu concentrations and decreased ferroxidase activity in the cerebrospinal fluid. Available data in Wilson's disease suggest that substantial increases in CNS Cu concentrations persist for a long time during chelating treatment and that local accumulation of Fe in certain brain nuclei may occur during the course of the disease. Consequences for chelating treatment strategies are discussed.

Role of the P-Type ATPases, ATP7A and ATP7B in brain copper homeostasis

Over the past two decades there have been significant advances in our understanding of copper homeostasis and the pathological consequences of copper dysregulation. Cumulative evidence is revealing a complex regulatory network of proteins and pathways that maintain copper homeostasis. The recognition of copper dysregulation as a key pathological feature in prominent neurodegenerative disorders such as Alzheimer's, Parkinson's, and prion diseases has led to increased research focus on the mechanisms controlling copper homeostasis in the brain. The copper-transporting P-type ATPases (copper-ATPases), ATP7A and ATP7B, are critical components of the copper regulatory network. Our understanding of the biochemistry and cell biology of these complex proteins has grown significantly since their discovery in 1993. They are large polytopic transmembrane proteins with six copper-binding motifs within the cytoplasmic N-terminal domain, eight transmembrane domains, and highly conserved catalytic domains. These proteins catalyze ATP-dependent copper transport across cell membranes for the metallation of many essential cuproenzymes, as well as for the removal of excess cellular copper to prevent copper toxicity. A key functional aspect of these copper transporters is their copper-responsive trafficking between the trans-Golgi network and the cell periphery. ATP7A- and ATP7B-deficiency, due to genetic mutation, underlie the inherited copper transport disorders, Menkes and Wilson diseases, respectively. Their importance in maintaining brain copper homeostasis is underscored by the severe neuropathological deficits in these disorders. Herein we will review and update our current knowledge of these copper transporters in the brain and the central nervous system, their distribution and regulation, their role in normal brain copper homeostasis, and how their absence or dysfunction contributes to disturbances in copper homeostasis and neurodegeneration.

Biochemical, histological, and memory impairment effects of chronic copper toxicity: a model for non-Wilsonian brain copper toxicosis in Wistar rat

Animal models of copper toxicosis rarely exhibit neurological impairments and increased brain copper accumulation impeding the development of novel therapeutic approaches to treat neurodegenerative diseases having high brain Cu content. The aim of this study was to investigate the effects of intraperitoneally injected copper lactate (0.15 mg Cu/100 g body weight) daily for 90 days on copper and zinc levels in the liver and hippocampus, on biochemical parameters, and on neurobehavioral functions (by Morris water maze) of male Wistar rats. Copper-administered animals exhibited significantly decreased serum acetylcholinesterase (AChE) activity and impaired neuromuscular coordination and spatial memory compared to control rats. Copper-intoxicated rats showed significant increase in liver and hippocampus copper content (99.1 and 73 % increase, respectively), 40.7 % reduction in hepatic zinc content, and interestingly, 77.1 % increase in hippocampus zinc content with concomitant increase in copper and zinc levels in serum and urine compared to control rats. Massive grade 4 copper depositions and grade 1 copper-associated protein in hepatocytes of copper-intoxicated rats were substantiated by rhodanine and orcein stains, respectively. Copper-intoxicated rats demonstrated swelling and increase in the number of astrocytes and copper deposition in the choroid plexus, with degenerated neurons showing pyknotic nuclei and dense eosinophilic cytoplasm. In conclusion, the present study shows the first evidence in vivo that chronic copper toxicity causes impaired spatial memory and neuromuscular coordination, swelling of astrocytes, decreased serum AChE activity, copper deposition in the choroid plexus, neuronal degeneration, and augmented levels of copper and zinc in the hippocampus of male Wistar rats.

Wilson's disease

In the almost 100 years since Wilson's description of the illness that now bears his name, tremendous advances have been made in our understanding of this disorder. The genetic basis for Wilson's disease - mutation within the ATP7B gene - has been identified. The pathophysiologic basis for the damage resulting from the inability to excrete copper via the biliary system with its consequent gradual accumulation, first in the liver and ultimately in the brain and other organs and tissues, is now known. This has led to the development of effective diagnostic and treatment modalities that, although they may not eliminate the disorder, do provide the means for efficient diagnosis and effective amelioration if carried out in a dedicated and persistent fashion. Nevertheless, Wilson's disease remains both a diagnostic and treatment challenge for physician and patient. Its protean clinical manifestations make diagnosis difficult. Appropriate diagnostic evaluations to confirm the diagnosis and institute treatment can be confusing. In this chapter, the clinical manifestations, diagnostic evaluation, and treatment approaches for Wilson's disease are discussed.

Copper-responsive magnetic resonance imaging contrast agents

The design, synthesis, and evaluation of the Copper-Gad (CG) family, a new class of copper-activated magnetic resonance imaging (MRI) contrast agents, are presented. These indicators comprise a Gd(3+)-DO3A core coupled to various thioether-rich receptors for copper-induced relaxivity switching. In the absence of copper ions, inner-sphere water binding to the Gd(3+) chelate is restricted, resulting in low longitudinal relaxivity values (r(1) = 1.2-2.2 mM(-1) s(-1) measured at 60 MHz). Addition of Cu(+) to CG2, CG3, CG4, and CG5 and either Cu(+) or Cu(2+) to CG6 triggers marked enhancements in relaxivity (r(1) = 2.3-6.9 mM(-1) s(-1)). CG2 and CG3 exhibit the greatest turn-on responses, going from r(1) = 1.5 mM(-1) s(-1) in the absence of Cu(+) to r(1) = 6.9 mM(-1) s(-1) upon Cu(+) binding (a 360% increase). The CG sensors are highly selective for Cu(+) and/or Cu(2+) over competing metal ions at cellular concentrations, including Zn(2+) at 10-fold higher concentrations. (17)O NMR dysprosium-induced shift and nuclear magnetic relaxation dispersion measurements support a mechanism in which copper-induced changes in the coordination environment of the Gd(3+) core result in increases in q and r(1). T(1)-weighted phantom images establish that the CG sensors are capable of visualizing changes in copper levels by MRI at clinical field strengths.

Copper intoxication; antioxidant defenses and oxidative damage in rat brain

Copper (Cu) is an integral part of many important enzymes involved in a number of vital biological processes. Even though Cu is essential to life, it can become toxic to cells, at elevated tissue concentrations. Oxidative damage due to Cu has been reported in recent studies in various tissues. In this study, we aimed to determine the effect of excess Cu on oxidative and anti-oxidative substances in brain tissue in a rat model. Sixteen male Wistar albino rats were divided into two groups: the control group, which was given normal tap water, and the experimental group, which received water containing Cu in a dose of 1 g/l. All rats were sacrificed at the end of 4 wk, under ether anesthesia. Cu concentration in the liver and in plasma alanine aminotransferase (ALT) and aspartate transaminase (AST) activities were determined. There were multiparameter changes with significant ALT and AST activity elevation and increased liver Cu concentration. In brain tissue, Cu concentration, superoxide dismutase (SOD) activities, malondialdehyde (MDA) levels and glutathione (GSH) concentrations were determined. Brain Cu concentration was significantly higher in rats receiving excess Cu, compared with control rats (p < 0.05). Our results showed that SOD activities and GSH levels in brain tissue of the Cu-intoxicated animals were significantly lower than in the control group (p < 0.01 and p < 0,001, respectively). The brain MDA levels were found to be significantly higher in the experimental group than in the control group (p < 0.001). The present results indicate that excessive Cu accumulation in the brain depressed SOD activities and GSH levels and resulted in high MDA levels in brain homogenate due to the lipid peroxidation induced by the Cu overload.

Differential profiles of copper-induced ROS generation in human neuroblastoma and astrocytoma cells

To determine neuronal and glial responses to copper (Cu) elevation in the CNS, human neuroblastoma and astrocytoma cells were used to compare their responses to Cu in terms of reactive oxygen species (ROS) generation and expression of enzymes responsible for anti-oxidation. Astrocytoma cells, not neuroblastoma cells, were responsive to Cu and Cu elevation was associated with ROS generation. Intracellular Cu levels as determined by inductively coupled plasma-mass spectrometry (ICP-MS), and expression levels of copper-transporting ATPase (ATP7A) and human copper transporter 1 (hCtr1) as detected by quantitative reverse transcription-polymerase chain reaction (RT-PCR), were comparable in both cell lines. Differences in Cu-induced ROS between two cell lines paralleled superoxide dismutase (SOD)-catalase expression as detected by Western blot analysis. Copper,zinc-SOD (Cu,Zn-SOD) and catalase protein levels were upregulated by Cu in neuroblastoma cells while Cu,Zn-SOD was down-regulated by Cu and catalase level was not changed in astrocytoma cells. Manganese-SOD (Mn-SOD) was not responsive to Cu in either cell line. Furthermore, 78-kDa glucose-regulated protein aggregation and upregulation were observed in Cu-treated astrocytoma cells, but not neuroblastoma cells. These data suggest that neurons use the SOD-catalase system to scavenge Cu-induced ROS while glia rely on the endoplasmic reticulum stress response to compensate for the reduction of ROS scavenging capacity.

In vivo reduction of amyloid-beta by a mutant copper transporter

Cu ions have been suggested to enhance the assembly and pathogenic potential of the Alzheimer's disease amyloid-beta (Abeta) peptide. To explore this relationship in vivo, toxic-milk (txJ) mice with a mutant ATPase7b transporter favoring elevated Cu levels were analyzed in combination with the transgenic (Tg) CRND8 amyloid precursor protein mice exhibiting robust Abeta deposition. Unexpectedly, TgCRND8 mice homozygous for the recessive txJ mutation examined at 6 months of age exhibited a reduced number of amyloid plaques and diminished plasma Abeta levels. In addition, homozygosity for txJ increased survival of young TgCRND8 mice and lowered endogenous CNS Abeta at times before detectable increases in Cu in the CNS. These data suggest that the beneficial effect of the txJ mutation on CNS Abeta burden may proceed by a previously undescribed mechanism, likely involving increased clearance of peripheral pools of Abeta peptide.

Copper in disorders with neurological symptoms: Alzheimer's, Menkes, and Wilson diseases

Copper is an essential element for the activity of a number of physiologically important enzymes. Enzyme-related malfunctions may contribute to severe neurological symptoms and neurological diseases: copper is a component of cytochrome c oxidase, which catalyzes the reduction of oxygen to water, the essential step in cellular respiration. Copper is a cofactor of Cu/Zn-superoxide-dismutase which plays a key role in the cellular response to oxidative stress by scavenging reactive oxygen species. Furthermore, copper is a constituent of dopamine-beta-hydroxylase, a critical enzyme in the catecholamine biosynthetic pathway. A detailed exploration of the biological importance and functional properties of proteins associated with neurological symptoms will have an important impact on understanding disease mechanisms and may accelerate development and testing of new therapeutic approaches. Copper binding proteins play important roles in the establishment and maintenance of metal-ion homeostasis, in deficiency disorders with neurological symptoms (Menkes disease, Wilson disease) and in neurodegenerative diseases (Alzheimer's disease). The Menkes and Wilson proteins have been characterized as copper transporters and the amyloid precursor protein (APP) of Alzheimer's disease has been proposed to work as a Cu(II) and/or Zn(II) transporter. Experimental, clinical and epidemiological observations in neurodegenerative disorders like Alzheimer's disease and in the genetically inherited copper-dependent disorders Menkes and Wilson disease are summarized. This could provide a rationale for a link between severely dysregulated metal-ion homeostasis and the selective neuronal pathology.

Dissolution of copper-rich granules in hepatic lysosomes by D-penicillamine prevents the development of fulminant hepatitis in Long-Evans cinnamon rats

BACKGROUND/AIM

The Long-Evans cinnamon rat has a mutation homologous to the human Wilson disease gene, leading to gross copper accumulation and the development of hepatitis. D-penicillamine, a copper-chelating drug widely and efficiently used in treating Wilson disease, has also been shown to prevent hepatitis in Long-Evans cinnamon rats. The objectives of this study were: i) to investigate the effectiveness of D-penicillamine when administered to the already affected animals, and ii) to elucidate the mechanism of action of the drug.

METHODS

Long-Evans cinnamon rats were divided into groups according to age and treatment with D-penicillamine. The drug was administered orally before and after the onset of hepatitis. Livers were examined by light and electron microscopy. The effect of D-penicillamine on the subcellular distribution and binding of copper was investigated in more detail. Finally, the interaction between D-penicillamine and specific hepatic copper-binding proteins was studied in vitro.

RESULTS

D-penicillamine when given to either healthy or diseased animals prevented or reversed hepatitis, respectively. The drug particularly inhibited the disease-specific accumulation of copper in lysosomes of hepatocytes, tissue macrophages and Kupffer cells. When administered to diseased animals, the drug sequestered copper particularly from insoluble lysosomal particles. According to results obtained in vitro, the mobilization of this copper is likely to proceed through the solubilization of these particles. In contrast and as supported by the in vitro data, D-penicillamine had only a minor effect on copper bound to metallothionein in the cytosol.

CONCLUSION

Our findings on the Long-Evans cinnamon rat provide some conclusions on the mechanism of action of D-penicillamine in Wilson disease therapy. The drug prevents the formation or promotes the solubilization of copper-rich particles which occur in lysosomes of hepatocytes and Kupffer cells in the livers of patients with Wilson disease. Once chelated with D-penicillamine copper might then be excreted into urine. However, the mobilization of copper by D-penicillamine seems to be limited due to the binding of the metal to metallothionein in liver cytosol. This copper, even at relatively high concentrations, apparently may be well tolerated.

Effect of asphyxia on the composition of cationic elements in the perilymph

To elucidate the role of free radicals in the cochlea, cationic elements in the perilymph of the scala tympani in normal and asphyxic guinea pigs were measured by an inductively coupled plasma atomic emission spectrometer. The concentrations of 7 cationic elements (i.e., calcium, copper, iron, magnesium, phosphorus, lead and zinc) were measured simultaneously in a sample of the perilymph taken before, during and after asphyxia. There was no significant change in these cationic elements during asphyxia for 3 min. In contrast to the stationary level during asphyxia, the iron concentration was significantly elevated at 5 min after re-ventilation following asphyxia and decreased rapidly toward the pre-asphyxic level thereafter, although no significant change was observed in other cationic elements. These results were comparable to the theory of non-protein-bound iron accumulation produced by an O2-dependent mechanism during re-perfusion.

Wilson's disease with cerebral manifestation: monitoring therapy by CSF copper concentration

The clinical courses, cerebrospinal fluid (CSF) and serum copper concentrations and urinary copper excretions under different schemes of drug treatment in four patients with cerebral manifestations of Wilson's disease were monitored over 6-11 years. CSF copper concentration measurements were performed from the beginning of therapy onwards in three patients and from 16 months after initial treatment onwards in the fourth. CSF copper levels decreased slowly over the years in parallel with clinical improvements, and increased in one patient who interrupted therapy for 2 years. These findings confirm our hypothesis that the concentration of copper in the CSF is a valuable quantitative parameter reflecting the normalization of copper in the brain. Copper measurements during phases of initial neurological deterioration in two patients receiving D-penicillamine, and in one patient receiving D-penicillamine and zinc sulphate, revealed decreased free serum copper and CSF copper levels.

Changes of CSF-Cu and -Zn in children with acute lymphoblastic leukemia

In 20 Dutch children with acute lymphoblastic leukemia (ALL), Cu and Zn levels in cerebrospinal fluid (CSF) were studied during standard treatment (Protocol ALL-BFM-86/SNWLK-ALL-VII). CSF-Cu in 10 controls was 0.04 +/- 0.02 mumol/L, lower compared to values in adults. At the moment of diagnosis, CSF-Cu values were higher, 0.06 +/- 0.03 mumol/L, and during maintenance therapy lower, 0.01 +/- 0.01 mumol/L. Children with central nervous system (CNS) involvement ALL as judged by CAT Scan and EEG--in addition to cytology--showed lower CSF-Cu values compared to children without. CSF-Zn values were also measured. CSF-Zn was 0.05 mumol/L and did not vary. Cu/Zn molar ratios were increased at the onset of treatment, and decreased during maintenance therapy. The changes in CSF-Cu may follow the natural course of the disease or may relate to the success of treatment, reflecting a decrease of leukemia activity. Another explanation concerns a risk of CNS damage by low CSF-Cu causing neuron dysfunction. Conditions necessary for the interpretation of these results into a clinical strategy for followup study are outlined.

Motor impairment in Wilson's disease, I: Slowness of voluntary limb movements

Twenty-three patients with Wilson's disease (WD) treated with D-penicillamine underwent clinical examination, as well as laboratory and motor testing. The clinical findings were scored. Laboratory tests included determination of the caeruloplasmin level, the free serum copper level, 24 h urinary copper excretion, liver enzymes and in 10 patients liver copper content of a liver biopsy. Laboratory tests and clinical scores were correlated. To quantify impairment of voluntary movements in WD fastest possible isometric index finger extensions and fastest alternating finger movements were analysed. Eleven patients presented with abnormally slow and 15 with abnormally irregular voluntary movements. Slowness of alternating movements correlated with the clinical score. The clinical score also correlated with the duration of symptoms prior to onset of therapy. Motor testing turned out to be sensitive enough to monitor improvement of neurological symptoms after onset of therapy. Comparison with motor testing in other basal ganglia diseases and cerebellar patients showed differences to patients with Parkinson's and Huntington's disease and similarities to patients suffering from AIDS-related dementia. In a small number of WD-patients similar results as in patients with a degenerative cerebellar disease were found.

Motor impairment in Wilson's disease, II: Slowness of speech

The maximal syllable production rate (MSPR) and the ability to reproduce a given target frequency in the 1 to 8 Hz range by repeating the short syllable "ta" was tested in 20 patients with Wilson's disease (WD) and 20 normal subjects. MSPR was significantly reduced in the WD-patients. In the 1 to 5 Hz range normal subjects as well as WD-patients tended to produce slightly higher frequencies than the target frequencies. This hastening was maximal in normals between 4 to 5 Hz whereas in the WD-patients hastening mainly occurred between 3 to 4 Hz. The test results showed a considerable variation across the patients. This variation can be interpreted on the basis of the theory of coupled oscillators. Comparison of speech and finger movements revealed a highly significant correlation between MSPR and the highest possible frequency of voluntary alternating index finger movements. As an application of the presented test treatment effects on speech movements were demonstrated.

Metallic elements in the perilymph measured with an inductively-coupled plasma atomic emission spectrometer

Metallic elements in the perilymph of the scala tympani in normal and acoustically overstimulated guinea pigs were measured using a new method, an inductively-coupled plasma atomic emission spectrometry. The concentrations of phosphorus and eight metallic elements, i.e. calcium, copper, iron, potassium, magnesium, sodium, lead and zinc were measured simultaneously in a 2 microliters sample of perilymph. The mean concentration values of calcium, copper, iron, magnesium, phosphorus, lead and zinc were 2.03 mM, 38.5 microM, 69.3 microM, 0.822 mM, 0.851 mM, 43.5 microM and 25.0 microM, respectively. There was no significant effect of acoustic overstimulation on the concentrations of these elements except for magnesium, which decreased significantly after the exposure to a intense sound (2 kHz, 115 dB SPL) for 15 min. This is the first report describing the synchronous determination of metallic poly-elements, including copper, iron, lead and zinc, in the perilymph.

Correction of cerebrospinal fluid copper in Menkes kinky hair disease

A patient with Menkes Kinky Hair disease was treated with infusions of copper-histidine which resulted in normal copper values in the cerebrospinal fluid. This tends to confirm the in vitro data that copper is transported into the central nervous system complexed with histidine or other similar ligands.