Real world long-term outcomes in patients with mucopolysaccharidosis type II: A retrospective cohort study

Mol Genet Metab Rep. 2021 Oct 22;29:100816. doi: 10.1016/j.ymgmr.2021.100816.

PMID: 34745890

Kazuyoshi Tomita, Shungo Okamoto, Toshiyuki Seto

Highlights: The aim of this study was to investigate the decline of activities of daily living with symptomatic progression in patients with mucopolysaccharidosis type II (MPS II) and investigate the associated factors.

Abstract

Objective: This study looked at how activities of daily life declined as clinical symptoms progressed in patients with mucopolysaccharidosis type II (MPS II) and what factors were involved.

Methods: Clinical data from the medical records of 28 MPS II patients who attended our hospital between October 2007 and August 2019 were obtained retrospectively. Daily living activities were assessed by using a 5-point scale (from stage 1, indicating independent, to stage 5, indicating total assistance + medical care); the relationships of the interval years from stage 2 (mild symptoms) to stage 4 (total assistance) with therapeutic intervention, anti-drug antibodies (ADA), urinary glycosaminoglycans (uGAG), and genotypes were studied.

Results: There are eight attenuated types and 20 severe types. Furthermore, 20 patients received only enzyme replacement therapy (ERT), 5 patients had only hematopoietic stem cell transplantation (HSCT), and 3 patients received both therapies. Patients who began undergoing ERT (n = 6) and HSCT (n = 3) at stage 2 had mean interval years (standard deviation) of 3.5 (0.7) and 7.3 (3.3), respectively, from stage 2 to stage 4, whereas patients who did not receive treatment until stage 4 (n = 8) had a mean interval year (standard deviation) of 3.1 (1.5).

Conclusion: The findings of the study demonstrated a long-term process of changes in everyday activities in individuals with MPS II who were undergoing various treatments. Regardless of the stage at which ERT was began, the activity deteriorated in the severe type. In the patients who underwent HSCT early the activity diminished more slowly.

Keywords: Activities of daily living, Enzyme replacement therapy, Hematopoietic stem cell transplantation, Hunter syndrome, Long-term follow-up, Mucopolysaccharidosis