Obstructive Sleep Apnea in MPS: A Systematic Review of Pretreatment and Posttreatment Prevalence and Severity

Abstract The mucopolysaccharidoses (MPSs) are a group of inherited, metabolic disorders characterized by progressive multisystem accumulation of partially degraded glycosaminoglycans. This manifests with multilevel airway obstruction, presenting with obstructive sleep apnea (OSA). We systematically reviewed the literature to determine the severity and prevalence of OSA in MPS based on polysomnography analysis. Fifteen studies with 294 participants met the inclusion criteria for review. The pretreatment prevalence of OSA in MPS was 81% with a mean apnea-hypopnea index (AHI) of 10.4. Patients with MPS I are most significantly affected, with 75% suffering with moderate to severe OSA (mean AHI, 16.6). Enzyme replacement therapy (ERT) results in an almost significant reduction in OSA in MPS I (P = .06), while adenotonsillar surgery significantly improves AHI (P = .002). Obstructive sleep apnea least affects MPS III. There is a lack of long-term post-ERT and hematopoietic stem cell transplant data relating to OSA outcomes in this population, with further prospective studies required to determine the ongoing response to treatment.

Improved metabolic correction in patients with lysosomal storage disease treated with hematopoietic stem cell transplant compared with enzyme replacement therapy.

We compared substrate reduction in patients with lysosomal storage disorder treated with hematopoietic stem cell transplant and found that it was significantly reduced compared with patients treated with pharmacological enzyme replacement therapy. These data might support the wider application of hematopoietic stem cell transplant in the treatment of lysosomal storage disorders.