Immunoglobulin a nephropathy as the first clinical presentation of Wilson disease: a case report and literature review

Genetically Confirmed Wilson Disease: A Retrospective Cohort Study From Bahrain

Introduction Wilson disease (WD) is a rare inherited autosomal recessive disorder caused by a mutation in the ATP7B gene. This mutation affects copper metabolism, leading to the accumulation of copper in the liver, brain, cornea, and other tissues. If not treated, WD can lead to significant morbidities. This study aimed to display the prevalence, clinical presentations, diagnosis, treatment, and outcome of WD in Bahrain. Methods This is a retrospective cohort study of patients diagnosed with WD in the Department of Pediatrics, Salmaniya Medical Complex, Manama, Kingdom of Bahrain, from March 2002 to July 2024. The diagnosis of WD was based on clinical presentations, laboratory markers, radiological imaging, and genetic testing. Results Up to July 2024, eight patients from four families were diagnosed with WD in Bahrain. Accordingly, the prevalence of WD was 1.7 patients per 100,000 (0.002%). Parental consanguinity was noted in all families. Males were equal to females (n=4, 50% each). The mean age at presentation was 13 ± 3.6 years, ranging from 9 to 21 years. Three patients (37.5%) presented with hepatic manifestations, two (25%) with neurological manifestations, and three (37.5%) were detected upon family screening. Kayser Fleischer (KF) rings were found in two (25%) patients via slit lamp examination. Of the seven patients with available data, five (71.4%) had low serum copper, six (85.7%) had low serum ceruloplasmin, and six (85.7%) had high 24-hour urinary copper. Genetic testing was positive for the ATP7B gene variants in all patients, of which four members of one family had a novel mutation. Abdominal ultrasound revealed hepatic cirrhosis in four (50%) patients, increased hepatic echogenicity in five (62.5%), splenomegaly in three (37.5%) patients, and ascites in one (12.5%) patient. Brain magnetic resonance imaging (MRI) was positive in three (50%) out of six patients. All patients received copper chelating therapy. Six (75%) patients survived; one of them underwent living-related liver transplantation due to rapidly progressive neurological symptoms. Two (25%) patients died due to hepatic failure and encephalopathy. Conclusion WD is a rare disorder in Bahrain. This study presents eight patients with WD from four families. Five patients were symptomatic at presentation, while three were diagnosed upon genetic family screening. Hepatic manifestations were the most common presentation, followed by behavioral changes and neurological symptoms. Two patients had KF rings, while three had classical brain MRI findings. Genetic testing served as a confirmatory diagnostic tool that revealed a diversity of variants causing the disease, of which one variant was a novel mutation. Despite oral chelating therapy, morbidity and mortality remain high in patients with WD.

Cuproptosis associated cytoskeletal destruction contributes to podocyte injury in chronic kidney disease

The podocyte cytoskeleton determines the stability of podocyte structure and function, and their imbalance plays a pathogenic role in podocyte diseases. However, the underlying mechanism of podocyte cytoskeleton damage is not fully understood. Here, we investigate the specific role of cuproptosis in inducing podocyte cytoskeleton injury. In in vitro and in vivo studies, exposure to high levels of copper and adriamycin (ADR) caused significant increases in copper concentration in intracellular and renal tissue. Moreover, excessive accumulation of copper induced cuproptosis, resulting in the destruction of the podocyte cytoskeleton. However, inhibition of copper accumulation to reduce cuproptosis also significantly alleviated the damage of podocyte cytoskeleton. In addition, inhibition of cuproptosis mitigated ADR-induced mitochondrial damage as well as the production of reactive oxygen species and depolarization of mitochondrial membrane potential, and restored adenosine triphosphate (ATP) synthesis. Among the transcriptome sequencing data, the difference of CXCL5 (C-X-C motif chemokine ligand 5) was the most significant. Both high copper and ADR exposure can cause upregulation of CXCL5, and CXCL5 deletion inhibits the occurrence of cuproptosis, thereby alleviating the podocyte cytoskeleton damage. This suggests that CXCL5 may act upstream of cuproptosis that mediates podocyte cytoskeleton damage. In conclusion, cuproptosis induced by excessive copper accumulation may induce podocyte cytoskeleton damage by promoting mitochondrial dysfunction, thereby causing podocyte injury. This indicates that cuproptosis plays an important role in the pathogenesis of podocyte injury and provides a basis for seeking potential targets for the treatment of chronic kidney disease.NEW & NOTEWORTHY Cuproptosis induced by excessive copper accumulation leads to podocyte cytoskeleton damage by promoting mitochondrial dysfunction, and CXCL5 acts as an upstream signal mediating the occurrence of cuproptosis.

Kidney involvement in Wilson's disease: a review of the literature

Wilson's disease (WD) is a rare inherited disease due to the mutation of the ATP7B gene, resulting in impaired hepatic copper excretion and its pathological accumulation in various organs such as the liver, the nervous system, or the kidneys. Whereas liver failure and neuropsychiatric disorders are the most common features, less is known about the renal complications. We conducted a review of the literature to define the characteristics and pathophysiology of kidney involvement during WD. This review shed light on strong evidence for direct copper toxicity to renal tubular cells. Excessive tubular copper accumulation might present with various degrees of tubular dysfunction, ranging from mild hydroelectrolytic and acid-base disorders to complete Fanconi syndrome. Proximal and distal renal tubular acidosis also favors development of nephrolithiasis, nephrocalcinosis, and bone metabolism abnormalities. Indirect complications might involve renal hypoperfusion as occurs in hepatorenal or cardiorenal syndrome, but also tubular casts' formation during acute hemolysis, rhabdomyolysis, or bile cast nephropathy. Acute kidney failure is not uncommon in severe WD patients, and independently increases mortality. Finally, specific and long-term therapy by D-penicillamin, one of the most efficient drugs in WD, can cause glomerular injuries, such as membranous nephropathy, minimal-change disease, and, rarely, severe glomerulonephritis. Altogether, our study supports the need for interdisciplinary evaluation of WD patients involving nephrologists, with regular monitoring of tubular and glomerular functions, to provide adequate prevention of renal and bone involvement.

Clinical features and familial mutations in the coexistence of Wilson's disease and Alport syndrome: A case report

Background

Alport syndrome (AS) and Wilson's disease (WD) are genetic diseases that could lead to kidney damage. Herein, we report the clinical features and gene variants in a patient with WD and X-linked AS.

Case presentation

The proband was a 12-year-old boy diagnosed with AS coexisting with WD at the age of 11 years. The patient underwent a medical check-up when he was 4 years and 8 months. Laboratory tests revealed elevated liver enzymes, decreased serum ceruloplasmin, increased 24-h urinary copper excretion, and one variant in the ATP7B gene. Then, the patient was diagnosed with WD. After 2 months of treatment with D-penicillamine and zinc salt, his liver function had recovered to normal levels, but he presented with microscopic hematuria. The hematuria did not resolve after switching to dimercaptosuccinic acid from D-penicillamine. In addition, he presented with proteinuria 3 years later. A renal biopsy was performed more than 6 years after the patient was diagnosed with WD, and electron microscopy showed that the basement membrane thickness was uneven, layered, and focal torn. Copper staining was negative. A genetic analysis identified a hemizygous variant (c.1718G > A, p. Gly573Asp) in COL4A5 and a homozygous variant (c.2975C > T, p. Pro992leu) in ATP7B. The patient's urine protein-creatinine ratio was less than 1.0 mg/mg after a 1 year of follow-up, after enalapril was administered for treating AS.

Conclusion

This case highlights a lack of improvement in renal function after conventional treatment provides a possible indication for performing renal biopsy or genetic testing to determine the etiology in order to facilitate subsequent clinical management. Clinicians should prevent the occurrence of diagnostic inaccuracies caused by diagnostic anchoring because an accurate diagnosis is essential for achieving precise treatment and improved prognosis.

Genetic studies discover novel coding and non-coding mutations in patients with Wilson's disease in China

OBJECTIVES

Wilson disease (WD) is a rare autosomal recessive genetic disorder associated with various mutations in the ATP7B gene and leads to significant disability or death if untreated. Early diagnosis and proper therapy usually predict a good prognosis, especially in pre-symptomatic WD. Genetic testing provides an accurate and effective diagnostic method for the early diagnosis of WD.

METHODS

We recruited 18 clinically diagnosed WD patients from 16 unrelated families and two independent individuals. The next-generation sequencing of the ATP7B gene was performed. The 293T cell lines were divided into wild-type (WT) ATP7B and mutated ATP7B groups. Cell proliferation was determined by Cell Counting Kit-8 (CCK-8) assay and apoptosis was detected by Annexin V/propidium iodide (PI) assays.

RESULTS

Pedigree analysis showed that compound heterozygous variants (17/18, 94.44%) were present in the majority of WD patients. A total of 33 ATP7B gene variants were identified, including three variants with uncertain significance (VUS) [two splice mutations (c.51+2T>G, c.1543+40G>A) and one frameshift mutation (c.3532_3535del)]. The CCK-8 and apoptosis assays demonstrated that the VUS of ATP7B could significantly affect the transportation of copper.

CONCLUSIONS

The study revealed genetic defects of 16 Chinese families and two independent individuals with WD, which enriched the mutation spectrum of the ATP7B gene worldwide and provided valuable information for studying the mutation types of ATP7B in the Chinese populations. Genetic testing in WD patients is necessary to shorten the time to initiate therapy, reduce damage to the liver and improve the prognosis.