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

Challenges and Recent Advances in Diagnosing Wilson Disease

Wilson disease (WD) is a rare autosomal recessive disorder caused by ATP7B gene mutations, leading to pathological copper accumulation that primarily affects the liver, brain, and eyes. Diagnosing WD remains a significant challenge due to its highly variable clinical presentation, which ranges from asymptomatic biochemical abnormalities to acute liver failure and severe neuropsychiatric manifestations. Traditional diagnostic markers, such as serum ceruloplasmin, urinary copper excretion, and liver biopsy, lack sufficient specificity and sensitivity, often leading to delays in diagnosis and misclassification. Additionally, the absence of a single gold-standard test and the overlap with other hepatic and neurological disorders further complicate early detection. Recent advances in diagnostic techniques offer promising solutions to overcome these limitations. Novel biomarkers, including relative exchangeable copper (REC) and ATP7B protein quantification in dried blood spots have demonstrated improved accuracy in distinguishing WD from other conditions. Advanced imaging modalities, such as anterior segment optical coherence tomography (AS-OCT), quantitative susceptibility mapping (QSM), and copper-64 positron emission tomography imaging provide noninvasive tools for detecting early disease-related changes. Furthermore, next-generation sequencing (NGS) enhances genetic screening, facilitating earlier diagnosis, and family screening. A comprehensive approach integrating conventional and emerging diagnostic methodologies is essential for improving early detection and patient outcomes. Greater awareness of the limitations of traditional tests and the incorporation of novel biomarkers and imaging techniques into clinical practice can help refine diagnostic accuracy, reduce delays, and optimize treatment strategies for WD.

From blood drops to biomarkers: a scoping review of microsampling in mass spectrometry-based proteomics

BACKGROUND

Microsamples are simple blood sampling procedures utilizing small blood draws. Although microsamples are regularly used in some disciplines, proteomic analysis of these samples is an emerging field. Currently, it is unclear whether the quantitative precision and proteome coverage achieved in microsamples is comparable to plasma or serum. As a consequence, microsamples are not used in proteomics to the same degree as more traditional blood samples.

OBJECTIVES

The objective of this scoping review was to report the applications of microsamples within clinical mass spectrometry-based proteomics. This was accomplished by describing both proof-of-concept and clinical proteomics research within this field, with an additional evaluation of the newest advances regarding clinical proteomics.

INCLUSION CRITERIA

Original scientific literature was included where bottom-up mass spectrometry was used to analyze endogenous proteins from human microsamples.

METHODS

Relevant publications were sourced through three scientific databases (MEDLINE, EMBASE and Scopus) in addition to backward and forward citation searches through Scopus. Record screening was performed independently by two separate authors. The review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) guidelines.

RESULTS

A total of 209 records were screened for inclusion from database searches and 3157 records were screened from forward and backward citation searches, resulting in 64 eligible studies. An evaluation of proof-of-concept research within this field revealed that although microsamples are amenable to high-throughput proteomics using a variety of targeted and untargeted acquisition methods, quantification remained a relevant issue. Microsampling practices were heterogeneous, and no standard procedure existed for protein quantification. Clinical studies investigated protein expression in numerous disease or experimental groups, including hemoglobinopathies and immunodeficiency disorders.

CONCLUSION

The use of microsamples is increasing within the proteomics field and these samples are amenable to standard bottom-up workflows. Although microsamples present a clear advantage in terms of sampling procedure, both the sample collection and quantification procedures remain to be standardized. However, there is an incentive to address the remaining issues, since microsampling would greatly reduce the resources necessary to sample large cohorts within clinical proteomics, a field that currently lacks large discovery and validation cohorts.

A Copper-Based Photothermal-Responsive Nanoplatform Reprograms Tumor Immunogenicity via Self-Amplified Cuproptosis for Synergistic Cancer Therapy

Studies show that intracellular accumulation of copper ions causes cuproptosis, potentially enhancing anticancer immunity. However, the induction of cuproptosis inevitably faces challenges due to low intracellular copper deliver efficiency and collateral damage to normal tissues. This paper presents a self-amplified cuproptosis nanoplatform (CEL NP) composed of Cu2- XS hollow nanospheres (HNSs), elesclomol (ES), and phase-change material lauric acid (LA). Under NIR-II laser irradiation, the photothermal energy generated by Cu2- XS HNSs melts LA, facilitating the precise release of ES and copper ions within the tumor microenvironment. Notably, ES can traverse the cell membrane and form ES-Cu(II) complexes, thereby enhancing copper delivery within tumor cells. Excess Cu(II) also reacts with endogenous glutathione, reducing its inhibitory effect on cuproptosis. Ultimately, this amplified cuproptosis effect can activate immunogenic cell death, eliciting a robust immune response and promoting tumor suppression. The CEL NP-mediated release of ES and copper ions offers a novel approach for anticancer therapy through cuproptosis induction.

Pathogenicity analysis of ATP7B in pediatric patients with Wilson's disease and functional verification of alternative splice variants

BACKGROUND

Wilson's disease (WD) is an autosomal recessive inherited disease caused by ATP7B gene mutations. Some mutations in ATP7B are presumed to be pathogenic by altering pre-mRNA splicing, while most have not been functionally verified. This study aimed to perform functional studies to verify the pathogenicity of variants that may affect pre-mRNA splicing.

METHODS

We recruited 42 pediatric patients who were clinically diagnosed with WD (Leipzig score ≥ 4) and underwent ATP7B gene sequencing. We leveraged in silico analysis and prioritized seven splice genic variants in ATP7B. Minigene assays were used to evaluate the effects of the selected variants on transcript splicing. Total RNA was extracted from peripheral blood mononuclear cells (PBMCs), and Reverse Transcription-Polymerase Chain Reaction (RT-PCR) was performed on samples from several patients to verify the splicing alterations.

RESULTS

This study screened 42 distinct mutations for their potential effects on splicing based on in silico analysis and functional verification. Five intronic variants (c.1286-1delG, c.1543 + 1G > T, c.1708-1G > C, c.1870-8A > G, and c.2121 + 3A > T) and one missense variant (c.2120A > G) were proved to alter the splicing of ATP7B transcription by minigene assays. The transcript assays demonstrated splicing changes in vivo in patient PBMCs for c.3993 T > G. The altered transcription products resulting from c.2570_2572del were confirmed by sequencing.

CONCLUSIONS

This study adds experimental evidence to genetic diagnosis based on assessing the genetic defects of 42 pediatric WD patients and provides new insights into the pathogenicity of the splicing variants.

EASL-ERN Clinical Practice Guidelines on Wilson's disease

Wilson's disease is an autosomal recessive disorder of copper metabolism which affects the liver, brain and other organs. Diagnosis is based on: clinical features; biochemical tests, including plasma ceruloplasmin concentration, 24-h urinary copper excretion, copper content in the liver; and molecular analysis. Leipzig score and additionally relative exchangeable copper determination are recommended for diagnosis. Pharmacological therapy comprises chelating agents (penicillamine, trientine) and zinc salts, while only chelators are recommended for significant liver disease. Monitoring is based on clinical symptoms, liver tests and copper metabolism (urinary copper excretion, exchangeable copper) to detect poor compliance and over/under-treatment. Acute liver failure is challenging as making a diagnosis is difficult and pharmacological therapy may not be sufficient to save life. Liver transplantation has a well-defined role in Wilsonian acute hepatic failure but may also be considered in neurological disease.

Spectrum and classification of ATP7B variants with clinical correlation in children with Wilson disease

OBJECTIVES

To study the spectrum and classification of ATP7B variants in Iraqi children with Wilson disease by direct gene sequencing with clinical correlation.

METHODS

Fifty-five unrelated children with a clinical diagnosis of Wilson disease (WD) were recruited. Deoxyribonucleic acid was extracted from peripheral blood samples, and variants in the ATP7B gene were identified using next-generation sequencing.

RESULTS

Seventy-six deleterious variants were detected in 97 out of 110 alleles of the ATP7B gene. Thirty (54.5%) patients had 2 disease-causing variants (15 homozygous and 15 compound heterozygous). Twelve (21.8%) patients had one disease-causing variant and one variant of uncertain significance (VUS) with potential pathogenicity. Thirteen (23.6%) patients were carriers of a single disease-causing variant. The most frequent variants, c.3305T>C and c.956delC, were detected in 4 alleles each, followed by c.3741-3742dupCA and c.3694A>C, which were detected in 3 alleles each. Among the 76 variants, 42 were missense, 13 were stop-gain, 9 were frameshift, 1 was an in-frame deletion, and 11 were intronic variants. Notably, the globally common variant H1069Q was not detected in this study.

CONCLUSION

The mutational spectrum of ATP7B in the Iraqi population is diverse, despite the high rates of consanguinity. It differs from that of neighboring countries. We provided evidence for ten VUS to be reclassified as deleterious, raising questions about the diagnostic criteria for patients with higher Leipzig scores and a single deleterious variant.

Advancing Newborn Screening in Washington State: A Novel Multiplexed LC-MS/MS Proteomic Assay for Wilson Disease and Inborn Errors of Immunity

For many genetic disorders, there are no specific metabolic biomarkers nor analytical methods suitable for newborn population screening, even where highly effective preemptive treatments are available. The direct measurement of signature peptides as a surrogate marker for the protein in dried blood spots (DBSs) has been shown to successfully identify patients with Wilson Disease (WD) and three life-threatening inborn errors of immunity, X-linked agammaglobulinemia (XLA), Wiskott-Aldrich syndrome (WAS), and adenosine deaminase deficiency (ADAD). A novel proteomic-based multiplex assay to detect these four conditions from DBS using high-throughput LC-MS/MS was developed and validated. The clinical validation results showed that the assay can accurately identify patients of targeted disorders from controls. Additionally, 30,024 newborn DBS samples from the Washington State Department of Health Newborn Screening Laboratory have been screened from 2022 to 2024. One true presumptive positive case of WD was found along with three false positive cases. Five false positives for WAS were detected, but all of them were premature and/or low-birth-weight babies and four of them had insufficient DNA for confirmation. The pilot study demonstrates the feasibility and effectiveness of utilizing this multiplexed proteomic assay for newborn screening.

Brain morphometry in hepatic Wilson disease patients

Wilson disease (WD) primarily presents with hepatic and neurological symptoms. While hepatic symptoms typically precede the neurological manifestations, copper accumulates in the brain already in this patient group and leads to subclinical brain MRI abnormalities including T2 hyperintensities and atrophy. This study aimed to assess brain morphological changes in mild hepatic WD. WD patients without a history of neurologic symptoms and decompensated cirrhosis and control participants underwent brain MRI at 3T scanner including high-resolution T1-weighted images. A volumetric evaluation was conducted on the following brain regions: nucleus accumbens, caudate, pallidum, putamen, thalamus, amygdala, hippocampus, midbrain, pons, cerebellar gray matter, white matter (WM), and superior peduncle, using Freesurfer v7 software. Whole-brain analyses using voxel- and surface-based morphometry were performed using SPM12. Statistical comparisons utilized a general linear model adjusted for total intracranial volume, age, and sex. Twenty-six WD patients with mild hepatic form (30 ± 9 years [mean age ± SD]); 11 women; mean treatment duration 13 ± 12 (range 0-42) years and 28 healthy controls (33 ± 9 years; 15 women) were evaluated. Volumetric analysis revealed a significantly smaller pons volume and a trend for smaller midbrain and cerebellar WM in WD patients compared to controls. Whole-brain analysis revealed regions of reduced volume in the pons, cerebellar, and lobar WM in the WD group. No significant differences in gray matter density or cortical thickness were found. Myelin or WM in general seems vulnerable to low-level copper toxicity, with WM volume loss showing promise as a marker for assessing brain involvement in early WD stages.

Peptide-based therapeutics targeting genetic disorders

Genetic disorders (GDs) are challenging to treat owing to a lack of optimal treatment regimens and intricate and often difficult-to-understand underlying biological processes. Limited therapeutic approaches, which mostly provide symptomatic relief, are available. To date, a limited number of peptide-based drugs for the treatment of GDs are available, and several candidates are under clinical study. This review provides mechanistic insights into GDs and potential target areas where peptide-based drugs are beneficial. In addition, it emphasizes the usefulness of peptides as carriers for gene delivery, biomarkers for mutation detection and peptide-based vaccines for treating GDs.

Wilson Disease: Novel Diagnostic and Therapeutic Approaches

The Wilson disease (WD) research field is rapidly evolving, and new diagnostic and therapeutical approaches are expected to be change-gamers in the disease for the incoming years, after decades of slow changing options. Non-ceruloplasmin-bound copper assays for circulating bioavailable copper are being tested for use in monitoring therapy and may also help in the diagnosis of new cases of WD. Other diagnostic advances include the use of quantitative detection of ATP7B peptides in dried blood spots, a method that is being tested for use in the newborn screening for WD, and the use of metallothionein immunostaining of liver biopsy specimens to differentiate WD from other liver diseases. Ongoing and future trials of gene therapy and use of methanobactin are expected to restore biliary copper excretion from the liver, thus making a cure for WD a plausible therapeutic objective. With the aim of helping updating physicians, this review summarizes the novel methods for WD diagnosis and future therapies. Advancing understanding of the scientific advances that can be applied to WD will be critical for ensuring that our patients will receive the best current and future care.

Next-Generation Sequencing of Chinese Children with Congenital Hearing Loss Reveals Rare and Novel Variants in Known and Candidate Genes

Background: Hearing loss (HL) is the most common disorder in newborns with a highly heterogeneous genetic background. Despite significant progress in screening and identifying genes related to congenital hearing loss, there are still candidate genes implicated in HL that remain undiscovered. Methods: We investigated HL in 43 Chinese families by segregating bilateral sensorineural HL via whole-exome sequencing (WES) and Sanger sequencing. Results: Variants were found in 10 known non-syndromic hearing loss (NSHL) genes, 5 known syndromic hearing loss (SHL) genes, and 1 candidate HL gene, ATP7B. RNA sequencing revealed ATP7B mRNA expression in developing and adult cochleae. The immunohistochemistry of the adult mouse cochlear tissue revealed the prominent expression of ATP7B in the organ of Corti and the spiral ganglion neuron. Overall, we propose a new candidate gene, ATP7B, for congenital hearing loss and novel variants in known HL genes, which expands our understanding of the etiology of HL. Conclusions: The next-generation sequencing could effectively improve the etiological diagnosis rate of congenital hearing loss in children.

Focus on cuproptosis: Exploring new mechanisms and therapeutic application prospects of cuproptosis regulation

Cuproptosis is a novel form of regulated cell death, which plays an important role in the physiological and pathological processes of the human body. Despite the increasing research on cuproptosis-related genes (CRGs) and their correlation with diseases, the pathogenesis of cuproptosis-related diseases remains unclear. Furthermore, there is a lack of reviews on the emerging technologies for regulating cuproptosis in disease treatment. This study delves into the copper-induced cell death mechanism, distinguishing cuproptosis from mechanisms like oxidative stress, glutathione synthesis inhibition, and ubiquitin-proteasome system inhibition. Several long-standing mysteries of diseases such as Wilson's disease and Menkes disease may be attributed to the occurrence of cuproptosis. In addition, we also review the detection indicators related to cuproptosis, providing targets for the diagnosis of cuproptosis-related diseases, and summarize the application value of cuproptosis in tumor therapy to better elucidate the impact of copper in cell death and diseases, and thus to promote the application prospects and possible strategies of cuproptosis-related substances, such as copper ion chelators, copper ion carriers, and copper nanomaterials, in disease therapy.

Cuproptosis and Cu: a new paradigm in cellular death and their role in non-cancerous diseases

Cuproptosis, a newly characterized form of regulated cell death driven by copper accumulation, has emerged as a significant mechanism underlying various non-cancerous diseases. This review delves into the complex interplay between copper metabolism and the pathogenesis of conditions such as Wilson's disease (WD), neurodegenerative disorders, and cardiovascular pathologies. We examine the molecular mechanisms by which copper dysregulation induces cuproptosis, highlighting the pivotal roles of key copper transporters and enzymes. Additionally, we evaluate the therapeutic potential of copper chelation strategies, which have shown promise in experimental models by mitigating copper-induced cellular damage and restoring physiological homeostasis. Through a comprehensive synthesis of recent advancements and current knowledge, this review underscores the necessity of further research to translate these findings into clinical applications. The ultimate goal is to harness the therapeutic potential of targeting cuproptosis, thereby improving disease management and patient outcomes in non-cancerous conditions associated with copper dysregulation.

Advancements in clinical approaches, analytical methods, and smart sampling for LC-MS-based protein determination from dried matrix spots

Determination of proteins from dried matrix spots using MS is an expanding research area. Mainly, the collected dried matrix sample is whole blood from a finger or heal prick, resulting in dried blood spots. However as other matrices such as plasma, serum, urine, and tear fluid also can be collected in this way, the term dried matrix spot is used as an overarching term. In this review, the focus is on advancements in the field made from 2017 up to 2023. In the first part reviews concerning the subject are discussed. After this, advancements made for clinical purposes are highlighted. Both targeted protein analyses, with and without the use of affinity extractions, as well as untargeted, global proteomic approaches are discussed. In the last part, both methodological advancements are being reviewed as well as the possibility to integrate sample preparation steps during the sample handling. The focus, of this so-called smart sampling, is on the incorporation of cell separation, proteolysis, and antibody-based affinity capture.

The potential serum sphingolipid biomarkers for distinguishing Wilson disease

BACKGROUND

The diagnosis of Wilson's disease (WD) remains a challenging endeavor in clinical practice. Serum sphingolipids play a significant role in the development of liver disease. In this study, we examined the serum sphingolipid profile in patients with WD and explored the potential diagnostic utility of serum sphingolipid metabolites. These metabolites may aid in distinguishing WD patients from healthy controls and identifying those with a risk of cirrhosis.

METHODS

This study consecutively enrolled 26 WD patients and 88 healthy controls. We utilized high-performance liquid chromatography-tandem mass spectrometry to analyze a panel of 88 serum sphingolipid metabolites. The data were analyzed by multivariate statistical methods.

RESULTS

Among the 88 sphingolipids metabolites analyzed, 17 sphingolipids were observed significant differences between WD and HC groups (all P < 0.05). Notably, five sphingolipids, namely S1P (d18:1), Cer (d18:2/21:0), SM41:2, sph(d18:1), and Cer (d18:2/22:0), each with an AUC exceeding 0.9, emerged as potential biomarkers for WD. Additionally, in the comparison between WD patients with and without cirrhosis, 24 sphingolipid metabolites exhibited significant differences (all P < 0.05). We identified Cer(d18:1/20:0), Cer(d18:2/22:0), Cer(d18:2/24:0), Cer(d18:2/20:0), and Cer(d18:2/18:0), each with an AUC exceeding 0.9, as potential serological markers for WD patients with cirrhosis.

CONCLUSION

For enhanced clinical applicability, we propose considering Cer (d18:2/22:0) as a predictive marker applicable to both WD patients and their susceptibility to cirrhosis. This particular ceramide has exhibited strong diagnostic and predictive performance. These findings have the potential to facilitate non-invasive WD diagnosis.

Cuproptosis Regulates Microenvironment and Affects Prognosis in Prostate Cancer

Current immunotherapy for prostate cancer is still in the stage of clinical trials. This delay is thought to be caused by an unclear regulatory mechanism of the immune microenvironment, which makes it impossible to distinguish patients suitable for immunotherapy. Cuprotosis may be related to the heterogeneity of immune microenvironment, which was regarded as a new copper-dependent cell death mode, was proposed, and gain attention. We explored for the first time the relationship between cuprotosis and the immune microenvironment of prostate cancer and constructed cuprotosis score. RNA sequencing data sets for prostate cancer were downloaded from public databases. Consensus clustering was applied to distinguish cuprotosis phenotype based on the expression of cuproptosis-related genes (CRGs) identified as prognostic factors. Genomic phenotypes of CRG clusters were depicted via consensus clustering. Cuprotosis score was established on the basis of differentially expressed genes (DEGs) identified as prognostic factors via principal component analysis. Cuprotosis score = the first principal component of prognostic factors + the second principal component of prognostic factors. The value of cuproptosis score in predicting prognosis and immunotherapy response was evaluated. PDHA1 (HR = 3.86, P < 0.001) and GLS (HR = 1.75, P = 0.018) were risk factors for prognosis of prostate cancer patients, while DBT (HR = 0.66, P = 0.048) was a favorable factor for prognosis of prostate cancer patients. CRG clusters had different prognosis and immune cell infiltration. So as gene clusters. Prostate cancer patients with low cuprotosis score showed better prognosis for biochemical relapse-free survival. Cuprotosis score is accompanied with high immune score and Gleason score. As cuprotosis genes, PDHA1, GLS, and DBT were identified as independent prognostic factors of prostate cancer. Cuprotosis score was established via principal component analysis of PDHA1, GLS, and DBT, which can be used as a predictor of prognosis and immunotherapy response of prostate cancer patients, and can characterize immune cells infiltration in tumors. Cuproptosis was involved in the regulation of immune microenvironment, which may depend on the effect of tricarboxylic acid cycle. Our study provided clues to reveal the relationship between copper death and immune microenvironment, highlighted the clinical significance of cuproptosis, and provided a reference for the development of personalized immunotherapy.

Recent advances in the diagnosis and management of Wilson's disease

In this editorial, the reader will be updated on novel epidemiological, diagnostic, and therapeutical proposals in the field of Wilson disease.

ATP7B R778L mutant hepatocytes resist copper toxicity by activating autophagy and inhibiting necroptosis

Wilson's disease (WD) is an inherited disease characterized by copper metabolism disorder caused by mutations in the adenosine triphosphatase copper transporting β gene (ATP7B). Currently, WD cell and animal model targeting the most common R778L mutation in Asia is lacking. In addition, the mechanisms by which hepatocytes resist copper toxicity remain to be further elucidated. In this study, we aimed to construct a novel WD cell model with R778L mutation and dissected the molecular basics of copper resistance. A novel HepG2 cell line stably expressing the ATP7B R778L gene (R778L cell) was constructed. The expression of necroptosis- and autophagy-related molecules was detected by PCR and Western blot (WB) in wild-type (WT) HepG2 and R778L cells with or without CuSO4 treatment. In addition, we detected and compared the levels of autophagy and necroptosis in CuSO4-treated R778L cells with the activation and inhibition of autophagy. Moreover, the mRNA and protein levels of autophagy and necroptosis signaling molecules were compared in R778L cells with the overexpression and knockdown of Unc-51 Like Autophagy Activating Kinase 1 (ULK1) and Autophagy Related 16 Like 1 (ATG16L1). We successfully constructed an R778L mutation HepG2 cell line. CuSO4 triggered the enhanced expression of autophagy and necroptosis signaling molecules in WT HepG2 cells and R778L cells. Remarkably, higher levels of autophagy and necroptosis were observed in R778L cells compared with those in WT cells. Autophagy activation led to weakened necroptosis mediated by RIPK3 and MLKL, conversely, autophagy inhibition brought about enhanced necroptosis. At the molecular level, ULK1- and ATG16L1 overexpression resulted in reduced necroptosis levels and vice versa. ULK1- and ATG16L1-mediated autophagy activation protects hepatocytes against RIPK3- and MLKL-mediated necroptosis in our new WD cell model treated with CuSO4. Targeted therapy by autophagy activation or necroptosis inhibition may be a novel and effective strategy to treat WD.

Tutorial review for peptide assays: An ounce of pre-analytics is worth a pound of cure

The recent increase in peptidomimetic-based medications and the growing interest in peptide hormones has brought new attention to the quantification of peptides for diagnostic purposes. Indeed, the circulating concentrations of peptide hormones in the blood provide a snapshot of the state of the body and could eventually lead to detecting a particular health condition. Although extremely useful, the quantification of such molecules, preferably by liquid chromatography coupled to mass spectrometry, might be quite tricky. First, peptides are subjected to hydrolysis, oxidation, and other post-translational modifications, and, most importantly, they are substrates of specific and nonspecific proteases in biological matrixes. All these events might continue after sampling, changing the peptide hormone concentrations. Second, because they include positively and negatively charged groups and hydrophilic and hydrophobic residues, they interact with their environment; these interactions might lead to a local change in the measured concentrations. A phenomenon such as nonspecific adsorption to lab glassware or materials has often a tremendous effect on the concentration and needs to be controlled with particular care. Finally, the circulating levels of peptides might be low (pico- or femtomolar range), increasing the impact of the aforementioned effects and inducing the need for highly sensitive instruments and well-optimized methods. Thus, despite the extreme diversity of these peptides and their matrixes, there is a common challenge for all the assays: the need to keep concentrations unchanged from sampling to analysis. While significant efforts are often placed on optimizing the analysis, few studies consider in depth the impact of pre-analytical steps on the results. By working through practical examples, this solution-oriented tutorial review addresses typical pre-analytical challenges encountered during the development of a peptide assay from the standpoint of a clinical laboratory. We provide tips and tricks to avoid pitfalls as well as strategies to guide all new developments. Our ultimate goal is to increase pre-analytical awareness to ensure that newly developed peptide assays produce robust and accurate results.

Dysregulation of Copper Metabolism in a Patient With Acute-on-Chronic Liver Failure Worked up for Fulminant Wilson Disease

Wilson disease (WD) is estimated present in 6%-12% of patients younger than 40 years hospitalized with acute liver failure (ALF). Fulminant WD carries a poor prognosis without treatment. A 36-year-old man with HIV, chronic hepatitis B virus, and alcohol use had ceruloplasmin 6.4 mg/dL and 24-hour urine copper 180 μg/L. WD workup was otherwise negative, including ophthalmic examination, hepatic copper quantification, ATP7B sequencing, and brain MRI. ALF commonly features copper dysregulation. Few studies on WD biomarkers have included fulminant WD. Our patient with WD biomarkers and other causes of liver failure highlights the need to study copper dysregulation in ALF.

Copper homeostasis dysregulation promoting cell damage and the association with liver diseases

ABSTRACT

Copper plays an important role in many metabolic activities in the human body. Copper level in the human body is in a state of dynamic equilibrium. Recent research on copper metabolism has revealed that copper dyshomeostasis can cause cell damage and induce or aggravate some diseases by affecting oxidative stress, proteasome, cuprotosis, and angiogenesis. The liver plays a central role in copper metabolism in the human body. Research conducted in recent years has unraveled the relationship between copper homeostasis and liver diseases. In this paper, we review the available evidence of the mechanism by which copper dyshomeostasis promotes cell damage and the development of liver diseases, and identify the future research priorities.

Liver disease in adolescents

In this article, we discuss common liver diseases in the adolescent population. We describe the initial evaluation of an adolescent presenting with new-onset liver enzyme abnormalities, based on the clinical history and physical examination. The management approach to the adolescent with liver disease is exemplified, including monitoring for adherence, risk-taking behaviours and focusing on psychosocial aspects of their care. Finally, we highlight the challenges of caring for the adolescent patient and the importance of addressing not only the liver disease but, more importantly, the holistic approach towards their management.

First-Tier Next Generation Sequencing for Newborn Screening: An Important Role for Biochemical Second-Tier Testing

There is discussion of expanding newborn screening (NBS) through the use of genomic sequence data; yet, challenges remain in the interpretation of DNA variants. Population-level DNA variant databases are available, and it is possible to estimate the number of newborns who would be flagged as having a risk for a genetic disease (including rare variants of unknown significance, VUS) via next-generation sequencing (NGS) positive. Estimates of the number of newborns screened as NGS positive for monogenic recessive diseases were obtained by analysis of the Genome Aggregation Database (gnomAD). For a collection of diseases for which there is interest in NBS, we provided 2 estimates for the expected number of newborns screened as NGS positive. For a set of lysosomal storage diseases, we estimated that 100 to approximately 600 NGS screen positives would be found per disease per year in a large NBS laboratory (California), and this figure may be expected to rise to a limit of about 1000 if we account for the fact that gnomAD does not contain all worldwide variants. The number of positives would drop 2.5- to 10-fold if the 10 VUS with highest allele frequency were biochemically annotated as benign. It is proposed that a second-tier biochemical assay using the same dried blood spot could be carried out as a filter and as part of NBS to reduce the number of high-risk NGS positive newborns to a manageable number.

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.

Wilson's disease: best practice

Wilson's disease is an autosomal recessive disorder arising from pathogenic variants in the Atp7b gene on chromosome 13. The defective translated ATPase copper (Cu) transport protein produced leads to Cu accumulation, initially affecting the liver but eventually affecting other cells. It is just over 20 years since the last Best Practice on this topic in this journal. This review is an update on this, covering new disease biomarkers, pathogenesis, assumptions around clinical features and developments in therapy.

Missing heritability of Wilson disease: a search for the uncharacterized mutations

Wilson disease (WD), a copper metabolism disorder caused by mutations in ATP7B, manifests heterogeneous clinical features. Interestingly, in a fraction of clinically diagnosed WD patients, mutations in ATP7B appears to be missing. In this review we discuss the plausible explanations of this missing heritability and propose a workflow that can identify the hidden mutations. Mutation analyses of WD generally includes targeted sequencing of ATP7B exons, exon-intron boundaries, and rarely, the proximal promoter region. We propose that variants in the distal cis-regulatory elements and/or deep intronic variants that impact splicing might well represent the hidden mutations. Heterozygous del/ins that remain refractory to conventional PCR-sequencing method may also represent such mutations. In this review, we also hypothesize that mutations in the key copper metabolism genes, like, ATOX1, COMMD1, and SLC31A1, could possibly lead to a WD-like phenotype. In fact, WD does present overlapping symptoms with other rare genetic disorders; hence, the possibility of a misdiagnosis and thus adding to missing heritability cannot be excluded. In this regard, it seems that whole-genome analysis will provide a comprehensive and rapid molecular diagnosis of WD. However, considering the associated cost for such a strategy, we propose an alternative customized screening schema of WD which include targeted sequencing of ATP7B locus as well as other key copper metabolism genes. Success of such a schema has been tested in a pilot study.

The modern face of newborn screening

Newborn screening (NBS) has been developed for years to identify newborns with severe but treatable conditions. Taiwan's NBS system, after the initial setup for a total coverage of newborns in 1990s, was later optimized to ensure the timely return of results in infants with abnormal results. Advancements in techniques such as Tandem mass spectrometry enable the screening into a multiplex format and increase the conditions to be screened. Furthermore, advances in therapies, such as enzyme replacement therapy, stem cell transplantation, and gene therapy, significantly expand the needs for newborn screening. Advances in genomics and biomarkers discovery improve the test accuracy with the assistance of second-tier tests, and have the potential to be the first-tier test in the future. Therefore, challenge of NBS now is the knowledge gap, including the evidence of the long-term clinical benefits in large cohorts especially in conditions with new therapies, phenotypic variations and the corresponding management of some screened diseases, and cost-effectiveness of extended NBS programs. A short-term and a long-term follow-up program should be implemented to gather those outcomes better especially in the genomic era. Ethical and psychosocial issues are also potentially encountered frequently. Essential education and better informed consent should be considered fundamental to parallel those new tests into future NBS.

Wilson Disease and Alpha1-Antitrypsin Deficiency: A Review of Non-Invasive Diagnostic Tests

Wilson disease and alpha1-antitrypsin deficiency are two rare genetic diseases that may impact predominantly the liver and/or the brain, and the liver and/or the lung, respectively. The early diagnosis of these diseases is important in order to initiate a specific treatment, when available, ideally before irreversible organ damage, but also to initiate family screening. This review focuses on the non-invasive diagnostic tests available for clinicians in both diseases. These tests are crucial at diagnosis to reduce the potential diagnostic delay and assess organ involvement. They also play a pivotal role during follow-up to monitor disease progression and evaluate treatment efficacy of current or emerging therapies.

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.

Liquid Chromatography-Tandem Mass Spectrometry in Newborn Screening Laboratories

Tandem mass spectrometry (MS/MS) is the most universal platform currently available for the analysis of enzymatic activities and biomarkers in dried blood spots (DBS) for applications in newborn screening (NBS). Among the MS/MS applications in NBS, the most common is flow-injection analysis (FIA-) MS/MS, where the sample is introduced as a bolus injection into the mass spectrometer without the prior fractionation of analytes. Liquid chromatography combined with MS/MS (LC-MS/MS) has been employed for second-tier tests to reduce the false-positive rate associated with several nonspecific screening markers, beginning two decades ago. More recently, LC-MS/MS has been applied to primary screening for new conditions for which FIA-MS/MS or other methods, including genomic screening, are not yet adequate. In addition to providing a list of the currently used LC-MS/MS-based assays for NBS, the authors share their experience regarding the maintenance requirements of LC-MS/MS vs. FIA-MS/MS systems. The consensus is that the maintenance of LC-MS/MS and FIA-MS/MS instrumentation is similar, and LC-MS/MS has the advantage of allowing for a larger number of diseases to be screened for in a multiplex, cost-effective fashion with a high throughput and an adequate turnaround time.

Comprehensive multiomics analysis of cuproptosis-related gene characteristics in hepatocellular carcinoma

Background: The mechanism of copper-induced cell death, which is called cuproptosis, has recently been clarified. However, the integrated role of cuproptosis-related genes in hepatocellular carcinoma (HCC) and its relationship with immune characteristics are still completely unknown.

Methods: In this study, the expression, genetic, and transcriptional regulation states of 16 cuproptosis-related genes in HCC were systematically investigated. An unsupervised clustering method was used to identify distinct expression patterns in 370 HCC patients from the TCGA-HCC cohort. Differences in functional characteristics among different expression clusters were clarified by gene set variation analysis (GSVA). The abundances of immune cells in each HCC sample were calculated by the CIBERSORT algorithm. Next, a cuproptosis-related risk score was established based on the significant differentially expressed genes (DEGs) among different expression clusters.

Results: A specific cluster of HCC patients with poor prognosis, an inhibitory immune microenvironment, and high expression levels of immune checkpoint molecules was identified based on the expression of the 16 cuproptosis-related genes. This cluster of patients could be well-identified by a cuproptosis-related risk score system. The prognostic value of this risk score was validated in the training and two validation cohorts (TCGA-HCC, China-HCC, and Japan-HCC cohorts). Moreover, the overall expression status of the cuproptosis-related genes and the genes used to establish the cuproptosis-related risk score in specific cell types of the tumor microenvironment were preliminarily clarified by single-cell RNA (scRNA) sequencing data.

Conclusion: These results indicated that cuproptosis-related genes play an important role in HCC, and targeting these genes may ameliorate the inhibitory immune microenvironment to improve the efficacy of immunotherapy with immune checkpoint inhibitors (ICIs).

The Role of Zinc in the Treatment of Wilson’s Disease

Wilson’s disease (WD) is a hereditary disorder of copper metabolism, producing abnormally high levels of non-ceruloplasmin-bound copper, the determinant of the pathogenic process causing brain and hepatic damage and dysfunction. Although the disease is invariably fatal without medication, it is treatable and many of its adverse effects are reversible. Diagnosis is difficult due to the large range and severity of symptoms. A high index of suspicion is required as patients may have only a few of the many possible biomarkers. The genetic prevalence of ATP7B variants indicates higher rates in the population than are currently diagnosed. Treatments have evolved from chelators that reduce stored copper to zinc, which reduces the toxic levels of circulating non-ceruloplasmin-bound copper. Zinc induces intestinal metallothionein, which blocks copper absorption and increases excretion in the stools, resulting in an improvement in symptoms. Two meta-analyses and several large retrospective studies indicate that zinc is equally effective as chelators for the treatment of WD, with the advantages of a very low level of toxicity and only the minor side effect of gastric disturbance. Zinc is recommended as a first-line treatment for neurological presentations and is gaining acceptance for hepatic presentations. It is universally recommended for lifelong maintenance therapy and for presymptomatic WD.

Cuproptosis-Related Gene - SLC31A1, FDX1 and ATP7B - Polymorphisms are Associated with Risk of Lung Cancer

Background

Cuproptosis is a novel copper-dependent cell death, and the copper level was increased in lung cancer patients. However, few studies evaluated the association between single-nucleotide polymorphisms (SNPs) in cuproptosis-related genes and lung cancer risk.

Methods

Six SNPs of the SLC31A1, FDX1 and ATP7B genes were genotyped in a case-control cohort including 650 lung cancer cases and 650 controls using the MassARRAY platform.

Results

The minor alleles of SLC31A1-rs10981694 and FDX1-rs10488764 were associated with an increased risk of lung cancer (rs10981694: OR=1.455, 95% CI: 1.201-1.763, p<0.001; rs10488764: OR=1.483, 95% CI: 1.244-1.768, p<0.001). In contrast, the minor alleles of rs9535826 and rs9535828 in ATP7B were related to a decreased risk of the disease (rs9535826: OR=0.714, 95% CI: 0.608-0.838 p<0.001; rs9535828: OR=0.679, 95% CI: 0.579-0.796, p<0.001). The frequencies of rs10981694-TG/GG and rs10488764-GA/AA genotypes were significantly higher in lung cancer cases than that in controls, making them risk genotypes for the disease (p < 0.001); while the rs9535826-TG/GG and rs9535828-GA/AA genotypes were protective genotypes and associated with a reduced risk of the disease (p<0.001). Genetic model evaluation revealed that SLC31A1-rs10981694 and FDX1-rs10488764 were associated with a growing risk of lung cancer in dominant, recessive and log-additive models (p<0.001). Moreover, rs9535826 and rs9535828 in ATP7B were related to a declining risk of the disease in three genetic models (p<0.001). In addition, stratification analysis showed that FDX1-rs10488764 was risk variant for lung cancer in both smokers and nonsmokers, and was associated with risk of each pathological type of lung cancer (p<0.008).

Conclusion

The results shed new light on the correlation between cuproptosis-related genes and risk of lung cancer.

A rapid and non-invasive proteomic analysis using DBS and buccal swab for multiplexed second-tier screening of Pompe disease and Mucopolysaccharidosis type I

PURPOSE

Current newborn screening programs for Pompe disease (PD) and mucopolysaccharidosis type I (MPS I) suffer from a high false positive rate and long turnaround time for clinical follow up. This study aimed to develop a novel proteomics-based assay for rapid and accurate second-tier screening of PD and MPS I. A fast turnaround assay would enable the identification of severe cases who need immediate clinical follow up and treatment.

METHODS

We developed an immunocapture coupled with mass spectrometry-based proteomics (Immuno-SRM) assay to quantify GAA and IDUA proteins in dried blood spots (DBS) and buccal swabs. Sensitivity, linearity, reproducibility, and protein concentration range in healthy control samples were determined. Clinical performance was evaluated in known PD and MPS I patients as well as pseudodeficiency and carrier cases.

RESULTS

Using three 3.2 mm punches (~13.1 μL of blood) of DBS, the assay showed reproducible and sensitive quantification of GAA and IDUA. Both proteins can also be quantified in buccal swabs with high reproducibility and sensitivity. Infantile onset Pompe disease (IOPD) and severe MPS I cases are readily identifiable due to the absence of GAA and IDUA, respectively. In addition, late onset Pompe disease (LOPD) and attenuated MPS I patients showed much reduced levels of the target protein. By contrast, pseudodeficiency and carrier cases exhibited significant higher target protein levels compared to true patients.

CONCLUSION

Direct quantification of endogenous GAA and IDUA peptides in DBS by Immuno-SRM can be used for second-tier screening to rapidly identify severe PD and MPS I patients with a turnaround time of <1 week. Such patients could benefit from immediate clinical follow up and possibly earlier treatment.

Synonymous mutation in adenosine triphosphatase copper-transporting beta causes enhanced exon skipping in Wilson disease

Wilson disease (WD) is caused by biallelic pathogenic variants in adenosine triphosphatase copper-transporting beta (ATP7B); however, genetic testing identifies only one or no pathogenic ATP7B variant in a number of patients with WD. Synonymous single-nucleotide sequence variants have been recognized as pathogenic in individual families. The aim of the present study was to evaluate the prevalence and disease mechanism of the synonymous variant c.2292C>T (p.Phe764=) in WD. A cohort of 280 patients with WD heterozygous for a single ATP7B variant was investigated for the presence of c.2292C>T (p.Phe764=). In this cohort of otherwise genetically unexplained WD, the allele frequency of c.2292C>T (p.Phe764=) was 2.5% (14 of 560) compared to 7.1 × 10-6 in the general population (2 of 280,964 in the Genome Aggregation Database; p < 10-5 ; Fisher exact test). In an independent United Kingdom (UK) cohort, 2 patients with WD homozygous for p.Phe764= were identified. RNA analysis of ATP7B transcripts from patients homozygous or heterozygous for c.2292C>T and control fibroblasts showed that this variant caused high expression of an ATP7B transcript variant lacking exon 8. Conclusion: The synonymous ATP7B variant c.2292C>T (p.Phe764=) causes abnormal messenger RNA processing of ATP7B transcripts and is associated with WD in compound heterozygotes and homozygotes.

Metallothionein immunohistochemistry has high sensitivity and specificity for detection of Wilson disease

Diagnosis of Wilson disease (WD) can be difficult because of its protean clinical presentations, but early diagnosis is important because effective treatment is available and can prevent disease progression. Similarly, diagnosis of WD on liver biopsy specimens is difficult due to the wide range of histologic appearances. A stain that could help identify WD patients would be of great value. The goal of this study was to use mass spectrometry-based proteomics to identify potential proteins that are differentially expressed in WD compared to controls, and could serve as potential immunohistochemical markers for screening. Several proteins were differentially expressed in WD and immunohistochemical stains for two (metallothionein (MT) and cytochrome C oxidase copper chaperone (COX17)) were tested and compared to other methods of diagnosis in WD including copper staining and quantitative copper assays. We found diffuse metallothionein immunoreactivity in all liver specimens from patients with WD (n = 20); the intensity of the staining was moderate to strong. This staining pattern was distinct from that seen in specimens from the control groups (none of which showed strong, diffuse staining), which included diseases that may be in the clinical or histologic differential of WD (steatohepatitis (n = 51), chronic viral hepatitis (n = 40), autoimmune hepatitis (n = 50), chronic biliary tract disease (n = 42), and normal liver (n = 20)). COX17 immunostain showed no significant difference in expression between the WD and control groups. MT had higher sensitivity than rhodanine for diagnosis of WD. While the quantitative liver copper assays also had high sensitivity, they require more tissue, have a higher cost, longer turnaround time, and are less widely available than an immunohistochemical stain. We conclude that MT IHC is a sensitive immunohistochemical stain for the diagnosis of WD that could be widely deployed as a screening tool for liver biopsies in which WD is in the clinical or histologic differential diagnosis.

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.

Biochemical diagnosis of Wilson's disease: an update

Wilson's disease (WD) is an inherited disorder of copper metabolism caused by mutations in the ATP7B gene. This condition is characterized by the accumulation of copper in the liver and other organs and tissues causing hepatic and neuropsychiatric manifestations. This paper reviews the diagnostic performance and limitations of the biochemical tests commonly used to detect this underdiagnosed disease. It also provides some recommendations and suggests a set of standardized laboratory comments. At present, a rapid, simple, reliable biochemical test that confirms diagnosis of WD is not available. However, diagnosis can be established based on serum ceruloplasmin and urinary copper excretion. Total serum copper should be employed with caution, since it has a low negative predictive value. The use of estimated non-ceruloplasmin-bound copper is not recommended. Nevertheless, measured relative exchangeable copper has very high sensitivity and specificity and emerges as a potential gold standard for the biochemical diagnosis of WD. The development of novel assays for WD detection makes this disorder a potential candidate to be included in newborn screening programs.

Wilson disease in children and young adults - State of the art

Wilson disease (WD) is an autosomal recessive disorder caused by mutations of the ATP7B gene, with a reported prevalence of 1:30,000-50,000. ATP7B encodes an enzyme called transmembrane copper-transporting ATPase, which is essential for copper incorporation into ceruloplasmin and for copper excretion into the bile. A lack or dysfunction of this enzyme results in a progressive accumulation of copper in several organs, especially in the liver, the nervous system, corneas, kidneys, and heart. Children with WD can present with asymptomatic liver disease, cirrhosis, or acute liver failure, with or without neurological and psychiatric symptoms. Approximately 20%-30% of WD patients present with ALF, while most of the other patients have chronic progressive hepatitis or cirrhosis if untreated. Although genetic testing has become a more important diagnostic tool for WD, the diagnosis remains based on both clinical features and laboratory investigations. The aims of treatment are to reduce copper levels and prevent its accumulation in the liver and other organs, especially in the central nervous system. Liver transplantation in WD is a life-saving option for patients presenting with liver failure and encephalopathy. For WD patients treated with chelating agents, adherence to the therapy is essential for long-term success. In this review, we also address specific issues in young adults as compared to children.

Wilson disease and the differential diagnosis of its hepatic manifestations: a narrative review of clinical, laboratory, and liver histological features

Objective

The goal of the present work is to provide an overview of the differential diagnosis of Wilson disease.

Background

Wilson disease is a rare condition due to copper accumulation primarily in the liver and brain. Although there is no definitive cure, current anti-copper treatments are associated with better outcomes if initiated early and if the diagnosis is made promptly. However, diagnostic delays are frequent and often Wilson disease represents a diagnostic challenge. The diagnosis ultimately relies on a combination of clinical, laboratory and genetic findings, and it is crucial that clinicians list Wilson disease in their differential diagnosis, especially in patients presenting with a hepatocellular pattern of liver injury. Some biochemical and liver histological features of Wilson disease overlap with those of more common conditions including nonalcoholic fatty liver disease, alcohol-associated liver disease, and autoimmune hepatitis. In particular, hepatic steatosis, hepatocyte glycogenated nuclei, ballooning degeneration, and Mallory-Denk bodies are often identified in Wilson disease as well as more common liver diseases. In addition, the natural history of liver damage in Wilson disease and the risk of developing liver cancer are largely understudied.

Methods

We conducted an enlarged review of published papers on Wilson disease focusing on its diagnosis and distinctive clinical and liver pathology features in relation to common non-cholestatic liver diseases with the final goal in aiding clinicians in the diagnostic process of this rare but treatable condition.

Conclusions

Aside from markedly altered copper metabolism, Wilson disease has essentially no pathognomonic features that can distinguish it from more common liver diseases. Clinicians should be aware of this challenge and consider Wilson disease in patients presenting with a hepatocellular pattern of liver injury.

Wilson's Disease: An Update on the Diagnostic Workup and Management

Wilson's disease (WD) is a rare autosomal recessive disorder of hepatocellular copper deposition. The diagnostic approach to patients with WD may be challenging and is based on a complex set of clinical findings that derive from patient history, physical examination, as well as laboratory and imaging testing. No single examination can unequivocally confirm or exclude the disease. Timely identification of signs and symptoms using novel biomarkers and modern diagnostic tools may help to reduce treatment delays and improve patient prognosis. The proper way of approaching WD management includes, firstly, early diagnosis and prompt treatment introduction; secondly, careful and lifelong monitoring of patient compliance and strict adherence to the treatment; and, last but not least, screening for adverse effects and evaluation of treatment efficacy. Liver transplantation is performed in about 5% of WD patients who present with acute liver failure at first disease presentation or with signs of decompensation in the course of liver cirrhosis. Increasing awareness of this rare inherited disease among health professionals, emphasizing their training to consider early signs and symptoms of the illness, and strict monitoring are vital strategies for the patient safety and efficacy of WD therapy.

Acute liver failure with hemolytic anemia in children with Wilson's disease: Genotype-phenotype correlations?

BACKGROUND

Wilson's disease (WD) is a rare autosomal recessive inherited disorder of copper metabolism. Acute liver failure (ALF) and hemolytic anemia represent the most severe presentation of WD in children. No clear genotype-phenotype correlations exist in WD. Protein-truncating nonsense, frame-shift, or splice-site variants may be associated with more severe disease. In contrast, missense variants may be associated with late-onset, less severe disease, and more neurological manifestations. Recently, a gene variant (HSD17B13:TA, rs72613567) with a possible hepatic protective role against toxins was associated with a less severe hepatic phenotype in WD.

AIM

To analyze the possible genotype-phenotype correlations in children with WD presented with ALF and non-immune hemolytic anemia.

METHODS

The medical records of children with WD diagnosed and treated in our hospital from January 2006 to December 2020 were retrospectively analyzed. The clinical manifestations (ALF with non-immune hemolytic anemia or other less severe forms), laboratory parameters, copper metabolism, ATP7B variants, and the HSD17B13:TA (rs72613567) variant were reviewed to analyze the possible genotype-phenotype correlations.

RESULTS

We analyzed the data of 51 patients with WD, 26 females (50.98%), with the mean age at the diagnosis of 12.36 ± 3.74 years. ALF and Coombs-negative hemolytic anemia was present in 8 children (15.67%), all adolescent girls. The Kayser-Fleisher ring was present in 9 children (17.65%). The most frequent variants of the ATP7B gene were p.His1069Gln (c.3207A>G) in 38.24% of all alleles, p.Gly1341Asp (c.4021G>A) in 26.47%, p.Trp939Cys (c.2817G>T) in 9.80%, and p.Lys844Ter (c.2530A>T) in 4.90%. In ALF with hemolytic anemia, p.Trp939Cys (c.2817G>T) and p.Lys844Ter (c.2530A>T) variants were more frequent than in other less severe forms, in which p.His1069Gln (c.3207A>G) was more frequent. p.Gly1341Asp (c.4021G>A) has a similar frequency in all hepatic forms. For 33 of the patients, the HSD17B13 genotype was evaluated. The overall HSD17B13:TA allele frequency was 24.24%. Its frequency was higher in patients with less severe liver disease (26.92%) than those with ALF and hemolytic anemia (14.28%).

CONCLUSION

It remains challenging to prove a genotype-phenotype correlation in WD patients. In children with ALF and hemolytic anemia, the missense variants other than p.His1069Gln (c.3207A>G) and frame-shift variants were the most frequently present in homozygous status or compound heterozygous status with site splice variants. As genetic analysis is usually time-consuming and the results are late, the importance at the onset of the ALF is questionable. If variants proved to be associated with severe forms are found in the pre-symptomatic phase of the disease, this could be essential to predict a possible severe evolution.

Wilson's disease- management and long term outcomes

Wilson's disease (WD) is an autosomal recessive genetic disorder of copper metabolism leading to liver or brain injury due to accumulation of copper. Diagnosis is based on: clinical features, biochemical tests including plasma ceruloplasmin concentration, 24h urinary copper excretion, copper content in the liver, and molecular analysis. Pharmacological therapy comprises chelating agents (penicillamine, trientine) and zinc salts which seem to be very effective. Still, poor compliance is a major problem. Adolescents and patients with psychiatric disorders usually have problems with adherence to treatment. As transition is a vulnerable period transition ''training'' should start before the planned transfer, preferably already in early adolescence in cooperation between adult and pediatric clinics. Response to treatment is assessed based on physical examination, normal liver function tests and monitoring of copper metabolism markers. Liver transplantation has a well-defined role in Wilsonian acute hepatic failure according to the prognostic score. The long-term survival in WD patients seems to be very similar as for the general population if disease is early diagnosed and correctly treated. WD patients with a longer delay from diagnosis to therapy and who present with neurological and psychiatric symptoms have worse quality of life.