Role for Biochemical Assays and Kayser-Fleischer Rings in Diagnosis of Wilson's Disease

Advancements in diagnostic approaches for Wilson's disease

Wilson's disease (WD) is a genetic disorder that results in excessive copper build-up in tissues, causing significant liver and neurological damage. Early and accurate diagnosis is crucial for effective management and treatment. Traditional diagnostic methods, including serum ceruloplasmin and urinary copper level monitoring, liver biopsy and genetic testing, are limited by sensitivity, specificity, invasiveness, and accessibility. Recent advances in diagnostic technologies offer new hope for more accurate, rapid, and non-invasive detection of WD. In this regard, nanotechnology-driven formulations hold significant promise for both the early diagnosis and treatment of WD. Through the innovative use of advanced nanomaterials, researchers are developing more effective therapeutic options and highly sensitive diagnostic tools, potentially transforming the management and prognosis of this genetic disorder. This review provides a comprehensive analysis of recent advancements in WD diagnostics, focusing on research published since 2016. It explores the development and application of novel biomarkers, advanced imaging modalities, innovative biosensors, and emerging nanotechnology-based approaches. By integrating these cutting-edge methodologies, the review highlights their potential to enhance early and accurate detection of WD, addressing current diagnostic challenges and improving clinical outcomes.

Clinical Characteristics, Treatment Effects and Risk Factors of Liver Cirrhosis in Patients with Wilson's Disease Hepatic Type

Background and Aims

Wilson's disease (WD) is a rare autosomal recessive genetic disorder that can be treated with medications. The lack of a single, specific diagnostic indicator leads to diagnostic difficulties, which may result in disease progression to cirrhosis and even liver cancer. Thus, this study aimed to analyze the clinical data, imaging, histopathological manifestations, genetic testing results, and treatment effects of patients with WD hepatic type, and to explore the factors related to WD cirrhosis.

Methods

A single-center retrospective study was performed. 48 WD patients with a Leipzig score ≥ 4 were divided into a cirrhosis group and a non-cirrhosis group based on the presence of cirrhosis. Logistic regression analysis and odds ratios were used to describe the strength of association between risk factors and cirrhosis. The predictive value of the model for cirrhosis occurrence was evaluated by calculating the area under the receiver operating characteristic curve and the cutoff value.

Results

All 48 patients diagnosed with WD had liver damage, with males accounting for 54.17%. The median age at diagnosis was 28 years (range: 10.25-40.5 years), and 39.58% of patients had cirrhosis. The most prevalent mutation was c.2333G>T (p.Arg778Leu), found in 41.30% (19/46) of cases. Imaging revealed fatty liver in 31.25% (15/48) of patients and "honeycomb-like" cirrhosis nodules in 73.68% (14/19). Compared with the non-cirrhosis group, the cirrhosis group had a higher positive rate for the Kayser-Fleischer (K-F) ring, older age at diagnosis, and higher levels of immunoglobulin G, but lower levels of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, white blood cells, and platelets (p < 0.05). Age at diagnosis (odds ratio = 1.072, 95% confidence interval = 1.007-1.142, p = 0.03) and the K-F ring (odds ratio = 18.657, 95% confidence interval = 1.451-239.924, p = 0.025) were independent risk factors for WD-related cirrhosis. The best values of area under the receiver operating characteristic curve for age at diagnosis combined with the K-F ring in predicting WD cirrhosis were 0.909. The average follow-up time for 33 patients was 48.6 months (range: 12-72 months). The biochemical recovery rate was over 60% after 12-72 months of treatment with zinc gluconate and/or penicillamine.

Conclusions

Age at diagnosis, combined with the K-F ring, is a simple and effective risk factor for WD-related cirrhosis. Zinc gluconate and penicillamine are safe and effective treatments.

Clinical and Molecular Spectrum of Wilson Disease in the Arab World: A Systematic Review

Wilson disease is a rare monogenic disease characterized by copper overload in various organs, mainly the liver, the brain and the eyes. It has a prevalence ranging between 1/30,000 and 1/50,000, and it is caused by pathogenic variants in the ATP7B gene, which encodes a copper-transporting ATPase essential for regulating liver copper levels by directing copper to the secretory pathway and exporting excess copper into bile. It is a fatal disease if left untreated; however early diagnosis and effective treatment enable patient's outcome improvement. Unfortunately, in the Arab world there is no collective data on Wilson disease. This systematic review presents an explicit overview on the clinical and molecular spectrum of Wilson disease in the Arab world. A literature search was conducted on five databases from their inception until April 2024, using a combination of words related to the genetics of Wilson disease in the Arab world. The search resulted in 48 relevant studies carried out in 13 Arab countries, in which 802 Wilson disease patients were reported, with a high rate of consanguinity, and a slight male predominance. Hepatic presentations were the most frequent features in patients, and a total of 92 variants were identified with a detection rate of 61.2%. Genotype-phenotype correlations were not established for the majority of variants. This review revealed a clinical and molecular heterogeneity of Wilson disease in the Arab world. Efforts from health authorities, clinicians and geneticists are recommended to improve diagnosis, reduce disease incidence and give more insights into the present-day understanding of Wilson disease in the Arab world.

Evaluation of salivary ceruloplasmin for the diagnosis of Wilson's disease

The serum ceruloplasmin assay is the most commonly used test for diagnosing Wilson's disease (WD). Despite the utility of non-invasive tests for diagnosing WD, no such tests have been developed. Therefore, we aimed to identify a safe and non-invasive assay and determine the factors associated with salivary ceruloplasmin. The sample comprised 167 participants: 130 patients with WD (experimental group) and 37 individuals without WD (control group). Salivary ceruloplasmin's diagnostic performance was assessed using a receiver operating characteristic curve analysis, and the diagnostic thresholds were determined. The Mann-Whitney U test for independent samples was used to compare intergroup variability between the control and WD groups. We used Pearson's correlation coefficient to determine intergroup correlations between the blood and salivary ceruloplasmin levels of patients with WD. Salivary ceruloplasmin levels were significantly lower in the WD group than in the control group. Serum and salivary ceruloplasmin levels were positively correlated. The area under the curve for salivary ceruloplasmin was 0.9977. The critical value of salivary ceruloplasmin was 8.885 ng/mL, with a sensitivity of 99.23% and specificity of 100%. Evidently, salivary ceruloplasmin has substantial diagnostic value. Therefore, saliva analysis can be used as a non-invasive alternative to serum analysis for diagnosing WD.

Clinical and genetic characterization of patients with late onset Wilson's disease

Wilson's disease (WD) typically manifests in children and young adults, with little knowledge of its late-onset forms. In this study, we performed a retrospective cohort study of 105 WD patients (99 index cases, 6 siblings) with an onset age ≥35 years. We compared 99 index late-onset patients with 1237 early-onset patients and analyzed the ATP7B variant penetrance referring to the Genome Aggregation Database (gnomAD). Sixty-two ATP7B variants were identified in the late-onset patients, among which A874V, V1106I, R919G, and T935M were correlated with late presentation of WD. Regarding gnomAD, V1106I and T935M exhibited significantly low penetrance, and there is a lack of patients carrying a genotype of V1106I/V1106I, R919G/R919G, T935M/T935M, V1106I/T935M, V1106I/R919G, or T935M/R919G. Our data revealed that patients carrying a combination of two late-onset variants may be overlooked due to atypical or lack of WD symptoms, which may provide valuable insights into the genetic basis and diagnosis of WD.

Gandouling induces GSK3β promoter methylation to improve cognitive impairment in Wilson's disease

ETHNOPHARMACOLOGIC SIGNIFICANCE

Cognitive impairment is a serious clinical manifestation of Wilson's disease (WD) in the nervous system. Gandouling (GDL) is a hospital preparation of the First Affiliated Hospital of Anhui University of Chinese Medicine. Previous studies have found that GDL has an ameliorative effect on cognitive impairment in WD.

AIM OF THE STUDY

We aimed to explore the molecular-level regulatory mechanisms underlying cognitive impairment in WD, and provide evidence supporting GDL as a promising candidate drug for the treatment of cognitive impairment in WD. We found that GSK3β was significantly up-regulated in the brain tissue of C3He-Atp7Btx-J/J (tx-j) mice in the WD gene mutant model, and the monomer components of GDL could combine well with GSK3β. Therefore, in this work, we used Behavioral tests, Hematoxylin and eosin (H&E), Nissl and Terminal deoxynucleotidyl transferase dUTP-biotin nick end labeling(TUNEL) staining, Ultrastructural morphological observation by Transmission electron microscopy (TEM), bisulfite sequencing (BSP), Quantitative real-time polymerase chain reaction (RT-qPCR), Western blot, immunofluorescence, network pharmacology, molecular docking, and related methods to study the effects of GDL in tx-j mice and HT22 cell to clarify the effect of GDL on cognitive impairment in WD.

RESULTS

In this study, MWM, NOR, H&E, Nissl TUNEL and TEM results showed that GDL could promote the repair of learning and memory function, improve the morphological damage to hippocampal neurons, and maintain mitochondria integrity. In the HT22 cell experiment, the CCK-8 method showed that GDL increased the viability of copper-overloaded cell models. The study found that GSK3β may be a target of GDL for the treatment of WD cognitive impairment through network pharmacology. Western blot and qRT-PCR results confirmed that GDL significantly increased the expression of proteins and mRNA in DNMT1, Nrf2, and HO-1. BSP showed that GSK3β promoter methylation was lower in the Model group than in the control group, and the promoter methylation of GSK3β was further reduced after intraperitoneal injection with decitabine, and GDL could ameliorate this pathology.

CONCLUSION

GDL demonstrates a protective role by inducing GSK3β promoter methylatio, regulating the GSK3β/Nrf2 signaling pathway in WD.

Constructing "smart" chelators by using an activatable prochelator strategy for the treatment of Wilson's disease

Wilson's disease (WD) is a genetic disorder that primarily leads to the pathological accumulation of copper (Cu) in the liver, causing an abnormal increase in reactive oxygen species (ROS). The prevailing clinical therapy for WD involves lifelong use of Cu chelation drugs to facilitate Cu excretion in patients. However, most available drugs exert severely side-effects due to their non-specific excretion of Cu, unsuitable for long-term use. In this study, we construct a prochelator that enables precise and controlled delivery of Cu chelator drugs to the liver in WD model, circumventing toxic side effects on other organs and normal tissues. This innovative prochelator rapidly releases the chelator and the fluorescent molecule methylene blue (MB) upon activation by ROS highly expressed in the liver of WD. The released chelator coordinates with Cu, efficiently aiding in Cu removal from the body and effectively inhibiting the pathological progression of WD.

Disorders of Copper Metabolism in Children-A Problem too Rarely Recognized

Copper plays an important role in metabolic processes. Both deficiency and excess of this element have a negative effect and lead to pathological conditions. Copper is a cofactor of many enzymatic reactions. Its concentration depends on the delivery in the diet, the absorption in enterocytes, transport with the participation of ATP7A/ATP7B protein, and proper excretion. Copper homeostasis disorders lead to serious medical conditions such as Menkes disease (MD) and Wilson's disease (WD). A mutation in the ATP7A gene is the cause of Menkes disease, it prevents the supply of copper ions to enzymes dependent on them, such as dopamine β-hydroxylase and lysyl oxidase. This leads to progressive changes in the central nervous system and disorders of the connective tissue. In turn, Wilson's disease is an inherited autosomal recessive disease. It is caused by a mutation of the ATP7B gene encoding the ATP7B protein which means excess copper cannot be removed from the body, leading to the pathological accumulation of this element in the liver and brain. The clinical picture is dominated by the liver, neurological, and/or psychiatric symptoms. Early inclusion of zinc preparations and chelating drugs significantly improves the prognosis in this group of patients. The aim of the study is to analyse, based on the latest literature, the following factors: the etiopathogenesis, clinical picture, diagnostic tests, treatment, prognosis, and complications of disease entities associated with copper disturbances: Menkes disease and Wilson's disease. In addition, it is necessary for general practitioners, neurologists, and gastroenterologists to pay attention to these disease entities because they are recognized too late and too rarely, especially in the paediatric population.

The Tao of Copper Metabolism: From Physiology to Pathology

As a transitional metal, copper plays a crucial role in maintaining the normal physiological activities of mammals. The intracellular copper concentration is meticulously regulated to maintain extremely low levels through homeostatic regulation. Excessive accumulation of free copper in cells can have deleterious effects, as observed in conditions such as Wilson's disease. Moreover, data accumulated over the past few decades have revealed a crucial role of copper imbalance in tumorigenesis, progression and metastasis. Recently, cuproptosis, also known as copper-induced cell death, has been proposed as a novel form of cell death. This discovery offers new prospects for treating copperrelated diseases and provides a promising avenue for developing copper-responsive therapies, particularly in cancer treatment. We present a comprehensive overview of the Yin- Yang equilibrium in copper metabolism, particularly emphasising its pathophysiological alterations and their relevance to copper-related diseases and malignancies.

Monitoring of Copper in Wilson Disease

(1) Introduction: Wilson's disease (WND) is an autosomal recessive disorder of copper (Cu) metabolism. Many tools are available to diagnose and monitor the clinical course of WND. Laboratory tests to determine disorders of Cu metabolism are of significant diagnostic importance. (2) Methods: A systematic review of the literature in the PubMed, Science Direct, and Wiley Online Library databases was conducted. (Results): For many years, Cu metabolism in WND was assessed with serum ceruloplasmin (CP) concentration, radioactive Cu test, total serum Cu concentration, urinary copper excretion, and Cu content in the liver. The results of these studies are not always unambiguous and easy to interpret. New methods have been developed to calculate non-CP Cu (NCC) directly. New parameters, such as relative Cu exchange (REC), reflecting the ratio of CuEXC to total serum Cu, as well as relative Cu exchange (REC), reflecting the ratio of CuEXC to total serum Cu, have been shown to be an accurate tool for the diagnosis of WND. Recently, a direct and fast LC-ICP-MS method for the study of CuEXC was presented. A new method to assess Cu metabolism during treatment with ALXN1840 (bis-choline tetrathiomolybdate [TTM]) has been developed. The assay enables the bioanalysis of CP and different types of Cu, including CP-Cu, direct NCC (dNCC), and labile bound copper (LBC) in human plasma. Conclusions: A few diagnostic and monitoring tools are available for patients with WND. While many patients are diagnosed and adequately assessed with currently available methods, diagnosis and monitoring is a real challenge in a group of patients who are stuck with borderline results, ambiguous genetic findings, and unclear clinical phenotypes. Technological progress and the characterization of new diagnostic parameters, including those related to Cu metabolism, may provide confidence in the more accurate diagnosis of WND in the future.

Structures of the human Wilson disease copper transporter ATP7B

The P-type ATPase ATP7B exports cytosolic copper and plays an essential role in the regulation of cellular copper homeostasis. Mutants of ATP7B cause Wilson disease (WD), an autosomal recessive disorder of copper metabolism. Here, we present cryoelectron microscopy (cryo-EM) structures of human ATP7B in the E1 state in the apo, the putative copper-bound, and the putative cisplatin-bound forms. In ATP7B, the N-terminal sixth metal-binding domain (MBD6) binds at the cytosolic copper entry site of the transmembrane domain (TMD), facilitating the delivery of copper from the MBD6 to the TMD. The sulfur-containing residues in the TMD of ATP7B mark the copper transport pathway. By comparing structures of the E1 state human ATP7B and E2-P_i state frog ATP7B, we propose the ATP-driving copper transport model of ATP7B. These structures not only advance our understanding of the mechanisms of ATP7B-mediated copper export but can also guide the development of therapeutics for the treatment of WD.

Construction of diagnostic prediction model for Wilson's disease

Background

Wilson's disease, also known as hepatolenticular degeneration, is a rare human autosomal recessive inherited disorder of copper metabolism. The clinical manifestations are diverse, and the diagnosis and treatment are often delayed. The purpose of this study is to establish a new predictive diagnostic model of Wilson's disease and evaluate its predictive efficacy by multivariate regression analysis of small trauma, good accuracy, low cost, and quantifiable serological indicators, in order to identify Wilson's disease early, improve the diagnosis rate, and clarify the treatment plan.

Methods

A retrospective analysis was performed on 127 patients with Wilson's disease admitted to the First People's Hospital of Yunnan Province from January 2003 to May 2022 as the experimental group and 73 patients with normal serological indicators who were not diagnosed with Wilson's disease. SPSS version 26.0 software was used for single factor screening and a multivariate binary logistic regression analysis to screen out independent factors. R version 4.1.0 software was used to establish an intuitive nomogram prediction model for the independent influencing factors included. The accuracy of the nomogram prediction model was evaluated and quantified by calculating the concordance index (C-index) and drawing the calibration curve. At the same time, the area under the curve (AUC) of the nomogram prediction model and the receiver operating characteristic (ROC) curve of the Leipzig score was calculated to compare the predictive ability of the nomogram model and the current Leipzig score for Wilson's disease.

Results

Alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (AKP), albumin (ALB), uric acid (UA), serum calcium (Ca), serum phosphorus (P), and hemoglobin (HGB) are closely related to the occurrence of Wilson's disease (p < 0.1). The prediction model of Wilson's disease contains seven independent predictors: ALT, AST, AKP, ALB, UA, Ca, and P. The AUC value of the prediction model was 0.971, and the C-index value was 0.972. The calibration curve was well fitted with the ideal curve. The nomogram prediction model had a good predictive effect on the occurrence of Wilson's disease; the ROC curve of Leipzig score was drawn, and the AUC value was calculated. The AUC of the Leipzig score was 0.969, indicating that the prediction model and the scoring system had predictive value, and the nomogram prediction model had a better predictive effect on the research objects of the center.

Conclusion

ALT, AST, AKP, ALB, UA, Ca, and P are independent predictors of Wilson's disease, and can be used as early predictors. Based on the nomogram prediction model, the optimal threshold was determined to be 0.698, which was an important reference index for judging Wilson's disease. Compared with the Leipzig score, the nomogram prediction model has a relatively high sensitivity and specificity and has a good clinical application value.

Pathogenicity of Intronic and Synonymous Variants of ATP7B in Wilson Disease

Wilson disease (WD) is a hereditary disorder of copper metabolism, resulting from mutations within ATP7B. Early diagnosis is essential for affected individuals. However, there are still patients with clinically suspected WD who do not have detectable pathogenic variants, which makes diagnosis difficult and delays treatment. This study included such patients from the authors' center and screened for the full-length sequence of ATP7B by next-generation sequencing. Newly identified synonymous and intronic variants were then analyzed with in silico tools. A minigene system was constructed to determine the pathogenicity of these variants in terms of splicing and blood RNA extraction, and RT-PCR experiments were performed on several patients to verify the splicing alterations. The phenotypes of the patients were also analyzed. Fourteen suspected pathogenic variants, including nine synonymous and five intronic variants, were detected in 12 patients with clinically suspected WD. Among them, four synonymous variants (c.1050G>A, c.1122C>G, c.3243G>A, and c.4014T>A) and four intronic variants (c.1543 +40G>A, c.1707+6_1707+16del, c.1870-49A>G, and c.2731-67A>G) resulted in splicing changes in ATP7B. After the above analysis, the diagnosis of WD could be confirmed in eight clinically suspected patients with WD who showed a late age of onset.

Clinical and genetic characterization of pediatric patients with Wilson's disease from Yunnan province where ethnic minorities gather

Background: Wilson's disease (WD) is an autosomal recessive disease that is caused by mutations in the ATP7B (a copper-transporting P-type ATPase) gene. The disease has a low prevalence and is characterized by a copper metabolism disorder. However, various characteristics of the disease are determined by race and geographic region. We aimed to discover novel ATP7B mutations in pediatric patients with WD from Yunnan province, where there is a high proportion of ethnic minorities. We also performed a comprehensive analysis of ATP7B mutations in the different ethnic groups found in Southwest China. Methods: We recruited 45 patients who had been clinically diagnosed with WD, from 44 unrelated families. Routine clinical examinations and laboratory evaluations were performed and details of age, gender, ethnic group and symptoms at onset were collected. Direct sequencing of the ATP7B gene was performed in 39 of the 45 patients and their families. Results: In this study, participants came from seven different ethnic groups in China: Han, Bai, Dai, Zhuang, Yi, Hui and Jingpo. Three out of ten patients from ethnic minorities presented with elevated transaminases, when compared to the majority of the Han patients. Forty distinct mutations (28 missense, six splicing, three non-sense, two frameshift and one mutation of uncertain significance) were identified in the 39 patients with WD. Four of the mutations were novel and the most frequent mutation was c.2333G > T (p.R778L, allelic frequency: 15.38%). Using the phenotype-genotype correlation analysis, patients from ethnic minorities were shown to be more likely to have homozygous mutations (p = 0.035) than Han patients. The patients who carried the c.2310C > G mutation had lower serum ceruloplasmin levels (p = 0.012). In patients with heterozygous mutations, c.3809A > G was significantly associated with ethnic minorities (p = 0.042). The frequency of a protein-truncating variant (PTV) in Han patients was 34.38% (11/32), while we did not find PTV in patients from ethnic minorities. Conclusion: This study revealed genetic defects in 39 pediatric patients with WD from Yunnan province. Four novel mutations were identified and have enriched the WD database. We characterized the genotypes and phenotypes in different minorities, which will enhance the current knowledge on the population genetics of WD in China.

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.

Acute-Onset Visual Impairment in Wilson's Disease: A Case Report and Literature Review

Objective

We reported the case of a patient with Wilson's disease (WD) with acute-onset visual impairment and summarized previously reported cases to make physicians aware of the complicated clinical expressions of WD and improve diagnosis efficiency.

Methods

The patient was recruited from the Second Affiliated Hospital of Zhejiang University School of Medicine. Clinical data, including cranial images, laboratory tests, and ophthalmic findings were obtained. The PubMed database was searched for published cases of WD with visual impairment.

Results

We reported a 22-year-old male who presented with hand tremor, personality change, and acute-onset binocular vision blurring. WD was considered to be closely correlated with neuropsychiatric and ocular involvements. After low-copper diet and regular copper-chelation therapy, the related symptoms improved compared to before. Six WD cases of optic neuropathy have been reported, including ours. The patients usually had neurological and/or hepatic symptoms for a period without any treatment. All the reported cases manifested as acute episodes of visual changes, and the ocular manifestations improved after copper-chelation treatment.

Conclusions

Excess copper accumulation may be a rare cause of visual impairment in patients with WD. While the etiology behind patients' acute-onset visual impairment remained uncertain, the possibility of WD should be considered through neuropsychiatric and hepatic symptoms, corneal K-F rings, decreased serum ceruloplasmin, and low likelihood or exclusion of other causes. Clinicians need to recognize this rare manifestation and give appropriate treatment to avoid misdiagnosis and unnecessary overtreatment.

Serum Neurofilament Light Chain in Wilson's Disease: A Promising Indicator but Unparallel to Real-Time Treatment Response

BACKGROUND

Wilson's disease (WD) currently lacks a promising indicator that could reflect neurological impairment and monitor treatment outcome. We aimed to investigate whether serum neurofilament light chain (sNfL) functions as a candidate for disease assessment and treatment monitoring of WD.

METHODS

We assessed preclinical and manifested WD patients' sNfL levels compared to controls and analyzed the differences between patients with various clinical symptoms. We then explored the correlation between clinical scales and sNfL levels. And repeated measurements were performed in 34 patients before and after treatment.

RESULTS

WD patients with neurological involvement had significantly higher sNfL levels than both hepatic patients and controls. Positive correlations were found between Unified Wilson's Disease Rating Scale scores and sNfL and between semiquantitative magnetic resonance imaging scales and sNfL levels in WD patients. However, in the treatment follow-up analysis, the trend of sNfL before and after treatment disaccorded with clinical response.

CONCLUSION

These findings suggest that sNfL levels can be an ideal indicator for the severity of neurological involvement but fail to evaluate change in disease condition after treatment. © 2022 International Parkinson and Movement Disorder Society.

Clinical and genetic characterization of a large cohort of patients with Wilson’s disease in China

Background

Wilson’s disease (WD) is an autosomal recessive disorder of copper metabolism caused by ATP7B (encoding a copper-transporting P-type ATPase) variants that shows various characteristics according to race and geographical region. This study was aimed to provide a comprehensive analysis of ATP7B variants in China and to investigate a plausible role of common variants in WD manifestations.

Methods

A total of 1366 patients (1302 index patients and 64 siblings) clinically diagnosed with WD (Leipzig score ≥ 4) were recruited. They underwent ATP7B gene sequencing and information of age and symptoms at onset was collected. The genotype–phenotype correlation was assessed in the index patients who were examined with two pathogenic variants and onset with hepatic (n = 276) or neurologic (n = 665) symptoms.

Results

We identified 294 potentially pathogenic ATP7B variants (112 truncating, 174 missense, 8 in-frame) in the 1302 index patients, including 116 novel variants. The most frequent variant was c.2333G>T (R778L, allele frequency: 28.96%), followed by c.2975C>T (P992L, 13.82%), c.2621C>T (A874V, 5.99%), c.2755C>G (R919G, 2.46%), and c.3646G>A (V1216M, 1.92%). In 1167 patients, both pathogentic variants were identified, of which 532 different variant combinations were found. By binary logistic regression analysis, the factor associated with neurological presentation was high age-at-onset, but not sex, protein-truncating variant (PTV), or the common missense variants (R778L, P992L, and A874V). In the neurological group, low age-at-onset was a factor associated with dystonia, gait abnormality, and salivation; high age-at-onset was a factor associated with tremor; and the sex, low age-at-onset and A874V were independent factors associated with dysarthria. In addition, PTV, R778L, and P992L were predominant in early-onset patients, whereas A874V was predominant in late-onset patients, and patients with R778L/A874V genotype displayed a higher age-at-onset than patients with R778L/R778L or R778L/P992L genotype.

Conclusions

Our work expanded the ATP7B variant spectrum and highlighted the differences among patients with WD in age-at-onset and ATP7B variants, which may provide some valuable insights into the diagnosis, counseling, and treatment of patients with WD.

Early Diagnosis of Wilson’s Disease in Children in Southern China by Using Common Parameters

Objective: The aim of the study was to develop the early diagnostic criteria for Wilson’s disease (WD) in young children in southern China by using alanine aminotransferase (ALT) elevation as the first manifestation.

Methods: A cross-sectional retrospective analysis of the clinical data and genetic test results of children with WD in southern China in the past 4 years and the follow-up of their short-term prognosis were performed in this study.

Results: A total of 30 children (5.08 ± 2.06 years old) with elevated ALT as the first manifestation of WD in southern China were enrolled in this study, including 14 females and 16 males. Specifically, in all of the 30 cases (100%), the serum ceruloplasmin (CP) level was decreased, whereas the 24-h urinary copper level was increased. The genetic mutation test of the ATP7B gene was used to confirm the diagnosis. In particular, the two mutation sites, including p.R778L and p.I1148T, had the highest mutation frequencies, approximately 23.0 and 10.7%, respectively. Through follow-up, most of the children had good recovery.

Conclusion: Early diagnosis and treatment of WD would substantially increase the survival rate and have a better prognosis. In addition, in 5-year-old children from southern China, early diagnosis could be performed quickly by referring to the following three parameters: elevated ALT, decreased ceruloplasmin level, and increased 24-h urinary copper level. It lays a foundation for further studies with a larger sample size.

Direct Measurement of ATP7B Peptides Is Highly Effective in the Diagnosis of Wilson Disease

BACKGROUND & AIMS

Both existing clinical criteria and genetic testing have significant limitations for the diagnosis of Wilson disease (WD), often creating ambiguities in patient identification and leading to delayed diagnosis and ineffective management. ATP7B protein concentration, indicated by direct measurement of surrogate peptides from patient dried blood spot samples, could provide primary evidence of WD. ATP7B concentrations were measured in patient samples from diverse backgrounds, diagnostic potential is determined, and results are compared with biochemical and genetic results from individual patients.

METHODS

Two hundred and sixty-four samples from biorepositories at 3 international and 2 domestic academic centers and 150 normal controls were obtained after Institutional Review Board approval. Genetically or clinically confirmed WD patients with a Leipzig score >3 and obligate heterozygote (carriers) from affected family members were included. ATP7B peptide measurements were made by immunoaffinity enrichment mass spectrometry.

RESULTS

Two ATP7B peptides were used to measure ATP7B protein concentration. Receiver operating characteristics curve analysis generates an area under the curve of 0.98. ATP7B peptide analysis of the sequence ATP7B 887 was found to have a sensitivity of 91.2%, specificity of 98.1%, positive predictive value of 98.0%, and a negative predictive value of 91.5%. In patients with normal ceruloplasmin concentrations (>20 mg/dL), 14 of 16 (87.5%) were ATP7B-deficient. In patients without clear genetic results, 94% were ATP7B-deficient.

CONCLUSIONS

Quantification of ATP7B peptide effectively identified WD patients in 92.1% of presented cases and reduced ambiguities resulting from ceruloplasmin and genetic analysis. Clarity is brought to patients with ambiguous genetic results, significantly aiding in noninvasive diagnosis. A proposed diagnostic score and algorithm incorporating ATP7B peptide concentrations can be rapidly diagnostic and supplemental to current Leipzig scoring systems.

Prevalent Pathogenic Variants of ATP7B in Chinese Patients with Wilson's Disease: Geographical Distribution and Founder Effect

Wilson’s disease (WD) is an autosomal recessive disorder caused by ATP7B pathogenic variants. This study aimed to show the geographical distribution and haplotype spectrum of three prevalent pathogenic variants (p.R778L, p.P992L, p.T935M) in mainland Chinese population and clarify whether the founder effect may account for their origins. We firstly summarized the frequency and geographical distribution of p.R778L, p.P992L and p.T935M in 715 WD patients. Then, to construct haplotypes associated with the three variants, Sanger sequencing and microsatellite typing at three dinucleotide-repeat markers (D13S314, D13S301, D13S316) flanking the ATP7B gene were performed in 102 WD families. An obvious regional-specific distribution feature was found in p.T935M. Linkage disequilibrium at the three markers was shown in all the three variants and we found the common haplotypes specific for p.R778L, p.P992L and p.T935M respectively, represented successively by 10-7-7, 10-9-5 and 12-4-8, which all exhibited great significance vs. the control chromosomes (p < 0.01). Meanwhile, haplotypes for the three variants differed from the studies in other regions to some extent. The common haplotypes we found indicate that three prevalent pathogenic variants emerge due to the founder effect. Furthermore, the study contributes to expand our knowledge of the genetic diversity of WD from a cross-regional perspective.