Epidemiology, treatment and burden of Wilson disease in France: A 10-year analysis of the national health insurance database

Portal hypertension and its prognostic implications in patients with Wilson's disease

BACKGROUND AND AIMS

Wilson's disease may progress to cirrhosis and clinically significant portal hypertension (CSPH). We aimed to assess the prevalence and prognostic impact of CSPH-related features on hepatic decompensation and transplant-free survival in patients with Wilson's disease.

METHODS AND RESULTS

About 137 patients with Wilson's disease (Leipzig score ≥4), followed for a median observation period of 9.0 (3.9-17.7) years at the Vienna General Hospital, were included in this retrospective study. Overall, 49 (35.8%) developed features of CSPH: 14 (10.2%) varices, 40 (29.2%) splenomegaly, 20 (14.6%) ascites, 18 (13.1%) hepatic encephalopathy and 3 (2.2%) experienced acute variceal bleeding. Overall, 8 (5.8%) patients died, including three deaths caused by CSPH-related complications. Within 10 years, compensated patients with features of CSPH developed more decompensation events (8.3% vs. 1.5% in patients without CSPH, p = 0.3) and had worse transplant-free-survival (91.7% vs. 98.6%), which further declined in patients with hepatic decompensation (26.7%, log-rank: p < 0.0001). Patients with liver stiffness <15 kPa and normal platelets (≥150 G/L) were less likely to decompensate within 10 years (2.6% vs. 8.4%, p = 0.002) and had a better 10-year transplant-free-survival (97.7% vs. 83.9%, p = 0.006).

CONCLUSIONS

Patients with Wilson's disease developing features of CSPH are at an increased risk for hepatic decompensation and liver-related mortality, warranting for regular screening and timely initiation of effective CSPH-directed treatments.

Characteristics of patients with Wilson disease in the United States: An insurance claims database study

BACKGROUND

Wilson disease (WD) is a progressive, potentially fatal degenerative disease affecting the liver and central nervous system. Given its low prevalence, collecting data on large cohorts of patients with WD is challenging. Comprehensive insurance claims databases provide powerful tools to collect retrospective data on large numbers of patients with rare diseases.

AIM

To describe patients with WD in the United States, their treatment and clinical outcome, using a large insurance claims database.

METHODS

This retrospective, longitudinal study was performed in the Clarivate Real-World Data Product database. All patients with ≥ 2 claims associated with an International Classification of Diseases 10 (ICD-10) diagnostic code for WD (E83.01) between 2016 and 2021 were included and followed until death or study end. Patients were divided into two groups by whether or not they were documented to have received a specific treatment for WD. Clinical manifestations, hospitalisations, liver transplantation and death were documented.

RESULTS

Overall, 5376 patients with an ICD-10 diagnostic code for WD were identified. The mean age at inclusion was 41.2 years and 52.0% were men. A specific WD treatment was documented for 885 patients (15.1%), although the number of patients taking zinc salts may be underestimated due to over the counter purchase. At inclusion, the mean age of patients with a documented treatment was 36.6 ± 17.8 years vs 42.2 ± 19.6 years in those without a documented treatment. During follow-up, 273 patients (5.1%) died. Compared with the American general population, the standardised mortality ratio was 2.19. The proportion of patients with a documented WD-specific treatment who died during follow-up was 4.0% and the mean age at death 52.7 years.

CONCLUSION

Patients treated for WD in the United States had an excess early mortality compared with the American population. These findings indicate that there is a significant unmet need for effective treatment for WD in the United States.

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.

Health-Related Quality of Life in Patients Living with Wilson Disease in Spain: A Cross-Sectional Observational Study

Wilson disease (WD) is a rare copper metabolism disorder caused by mutations in the ATP7B gene. It usually affects young individuals and can produce hepatic and/or neurological involvement, potentially affecting health-related quality of life (HRQoL). We assessed HRQoL in a cohort of Spanish patients with WD and evaluated disease impact on several domains of patients' lives, treatment adherence, drug preference and satisfaction, and healthcare resource utilisation in a cross-sectional, retrospective, multicentric, observational study. A total of 102 patients were included: 81.4% presented isolated liver involvement (group H) and 18.6% presented neurological or mixed involvement (group EH). Up to 30% of patients reported a deteriorated emotional status with anxiety and depression, which was greater in the EH subgroup; the use of neuropsychiatric drugs was high. Over 70% of the patients were satisfied with their current treatment but complained about taking too many pills, stating they would consider switching to another more patient-friendly treatment if available. The Simplified Medication Adherence Questionnaire revealed only 22.5% of patients were fully adherent to therapy, suggesting that alternative therapies are needed. This real-world study, even though is highly enriched with hepatic patients and mild disease, shows that WD impacts patients' HRQoL, especially in the emotional domain.

Experimental pharmacology: Targeting metabolic pathways

Since the discovery of the treatment for Wilson disease a growing number of treatable inherited dystonias have been identified and their search and treatment have progressively been implemented in the clinics of patients with dystonia. While waiting for gene therapy to be more widely and adequately translated into the clinical setting, the efforts to divert the natural course of dystonia reside in unveiling its pathogenesis. Specific metabolic treatments can rewrite the natural history of the disease by preventing neurotoxic metabolite accumulation or interfering with the cell accumulation of damaging metabolites, restoring energetic cell fuel, supplementing defective metabolites, and supplementing the defective enzyme. A metabolic derangement of cell homeostasis is part of the progression of many non-metabolic genetic lesions and could be the target for possible metabolic approaches. In this chapter, we provided an update on treatment strategies for treatable inherited dystonias and an overview of genetic dystonias with new experimental therapeutic approaches available or close to clinical translation.