Diagnosis, quality of life, and treatment of patients with Hunter syndrome in the French healthcare system: a retrospective observational study.

Nathalie Guffon,Bénédicte Heron,Vincent Montauban,Brigitte Chabrol,Vassili Valayannopoulos,François Feillet

doi:10.1186/s13023-015-0259-0

Abstract

BackgroundMucopolysaccharidosis II (MPS II) is associated with a broad spectrum of chronic and progressive, life-limiting symptoms. Idursulfase is approved for MPS II enzyme replacement therapy (ERT) in over 50 countries. This retrospective study evaluated the MPS II burden, organization of clinical care, and effects of idursulfase treatment on the disease in France.MethodsMPS II patients who had received idursulfase ERT in the French healthcare system were enrolled. In addition to clinician and patient questionnaires, the Clinical Global Impression-Improvement (CGI-I); Patient Global Impression-Improvement (PGI-I); KIDSCREEN-27, and EuroQoL-5D for adult patients scales were used to assess quality of life (QoL) and efficacy.ResultsFifty-two patients were enrolled from 5 sites in France. The majority of patients (69.2%) presented a severe MPS II phenotype with progressive neurocognitive impairment. Major impacts on QoL were apparent, with at least 1 member of the family having to reorganize working hours (45.5%) or to stop working (22.7%). KIDSCREEN-27 and EuroQoL-5D scale scores were well below those for referent (control) populations. Most families (70.0%) experienced a diagnostic delay of at least 3 years after the initial observation of symptoms. The MPS II diagnosis was often delivered without adequate sensitivity, psychological support, or comprehensive information about the disease. The study population had received a mean of 3.8 ± 1.3 years ERT. Forty-four percent of patients with the attenuated phenotype (without progressive neurocognitive impairment) showed symptom improvement during both the first year (Period 1) and from the end of the first year of treatment to “the present” (Period 2), as measured by CGI-I/PGI-I. 30.3% and 9.1% of severe patients experienced symptom improvement during Periods 1 and 2, respectively, while 63.6% and 51.5% displayed no change. The most common adverse reactions reported were skin rash and other infusion-associated reactions.ConclusionsMPS II adversely affects multiple domains of QoL for patients and families, requiring multiple healthcare services and social aid programs. The majority of patients with either phenotype experienced either improvement or stability in their symptoms during the first year of ERT, but this was clearly less so for patients with the severe phenotype after the first year of treatment.

Highlights

Mucopolysaccharidosis II (MPS II) is associated with a broad spectrum of chronic and progressive, life-limiting symptoms
Mucopolysaccharidosis II (MPS II), called Hunter syndrome, is a rare X-linked recessive lysosomal storage disease caused by iduronate-2-sulfatase enzyme deficiency, leading to accumulation of the glycosaminoglycans, heparan and dermatan sulfate
The aims of this study were to evaluate the burden of MPS II on the quality of life (QoL) of patients and families and on the healthcare and social services system in France, to document the organization and quality of clinical management of MPS II, and to describe the effects of idursulfase enzyme replacement therapy (ERT) on disease progression as perceived by clinicians and patients

Summary

Introduction

Mucopolysaccharidosis II (MPS II) is associated with a broad spectrum of chronic and progressive, life-limiting symptoms. Idursulfase is approved for MPS II enzyme replacement therapy (ERT) in over 50 countries. This retrospective study evaluated the MPS II burden, organization of clinical care, and effects of idursulfase treatment on the disease in France. The abnormal deposition of glycosaminoglycans results in dysfunction of multiple organs and systems and causes a broad spectrum of chronic and progressive, life-threatening symptoms [1]. The severe phenotype is more common, affecting about two-thirds of patients with MPS II, and is characterized by progressive cognitive impairment and developmental regression, with death usually occurring in the second decade of life. Patients with the attenuated phenotype have no severe cognitive impairment [2], but commonly suffer from joint stiffness and contractures, cardiac disease and respiratory infection, and may rarely display non-progressive cognitive impairment

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