This large prospective cross-sectional study examined the QoL in WD patients followed in a national reference center. Our cohort included patients of different age over 18, gender, and diseases phenotype covering the entire spectrum of WD. Moreover, this single-center recruitment allowed a homogeneous medical care between patients in term of treatments, follow-up and accessibility to various aid such as psychological support, social worker, or physiotherapist. In this cohort, QoL of WD patients seems to be globally good. For comparison, the mean EQ-5D-5L index value was 0.84 in Belgian general population (4) and 0.897 in the Spanish one (5). Interestingly, the mean VAS score in French general population was 77 ± 20.8 which is very close to our population (75.06 ± 20.68) (6). In a cohort of Spanish patients with a chronic disease (diabetes) the mean EQ-5D-5L index value was 0.67 and the mean VAS score was 61.1 which is lower than in our cohort (7). In our cohort, the length of follow-up and an easy access for the patients to an expert medical, paramedical and social care in a dedicated center to their rare disease, could explain the good QoL.
The QoL of our patients was related to the depressive state (higher in women and in HN patients) and, independently, to the HN phenotype of the disease. A recent systematic review of literature has showed that WD patients have a worse QoL than general population especially in patients with neurological form (8). Nevertheless, this review included very heterogenous studies without differentiation of the disease phenotypes, or with a focus on specific treatments (some studies included only WD patients without treatment, some with medical treatment only, and one studied WD after transplantation) or with different scales for assessing the QoL. Concerning LT, we found that it could impact the QoL of patients but it concerned only 5.4% of the global cohort. Except for a paper on 24 WD patients that found no significant difference between WD patients who had a LT and the general population (9), no recent study have assessed the QoL in liver transplanted WD patients.
Schaefer et al. have studied retrospectively the health-related quality of life and the risk for depression in 68 WD patients (10). Based on the PHQ-9 questionnaire, more than half of their patients were at risk for depression or suffered from depression and 21% were at high risk for major depressive disorder. These data contrast with our study; we found only 11% of patients with mild or severe depression. These differences could be explained by the larger size of our cohort (257 patients) and the design of the study: retrospective in Schaefer et al. and prospective in our, capturing more precisely the state of mind of the patients. Moreover, our center provides an easy access to psychologist care that could decrease the depression symptoms. Nevertheless, the QoL of their patient was similar to general population.
Different factors were associated with poorest QoL in the literature: gender (10), depression (8,11,12), neurological form of WD (8,10–13), treatments (10). We did not found effect of the treatment in our cohort, and it can be explained by the homogenous management of our patients due to our monocentric recruitment. The influence of gender has also been found in our study, with a statistically significant lower EQ-5D-5L index value score in women in univariate analysis. Nevertheless, this difference disappears in the multivariate analysis. This could be explained by a link between depression assessed by the BDI score and the female gender like in our study. This “female preponderance” in the level of self-report depressive symptoms have been demonstrated in the general population in a meta-analysis (14). On the other hand, the correlation between depression and impaired QoL in WD have been well demonstrated in a prospective study about 62 adults WD patients (p = 0.0017) [13]. Moreover, depression influence the QoL in different neurodegenerative disorders, even in the absence of significant motor and functional disability, enhancing its role as independent factor of QoL impairment like in our multivariate analysis (12). The impact of the neurological phenotype was also found statistically significant in our study. There might be several explanations for this finding. Patients with neurological symptoms develop symptoms later, have a longer time between beginning of symptoms and diagnosis and are diagnosed later in life exposing them to the possibility of irreparable tissue damage which impact the QoL (10).