LAUSR

Background: The loss of enzymatic activity in lysosomal storage diseases (LSD) results in progressive cellular accumulation of macromolecules. In these patients, respiratory dysfunction is usually a leading cause of morbidity and mortality. Thus, clinical assessments and objective measures of lung function, are crucial for prompt diagnosis and management. However, the use of spirometry is limited to patients who can perform forced expiration. Nevertheless, the forced oscillation technique (FOT) is performed during tidal breathing; thus, it is amenable to most patients who fail spirometry test. This study describes the feasibility of FOT in patients with LSD Methods: Patients with LSD at Tawam Hospital (Al Ain, UAE) were enrolled in the study in 2016 and 2017 (n=29); the mean ± SD age was 10±6 y. Their airway resistance was assessed using FOT at 5 Hz (Rrs5) and expressed as Rrs5 z-scores Results: Fifteen patients with mucopolysaccharidoses (MPS) were studied. Despite several attempts; the FOT study was successful in six patients (two patients with MPS-I, three with and MPS-IVA and one with MPS-VI). The mean Rrs5 z-scores for these patients was 1.99. The remaining ten patients with MPS-III failed to do the test Among the 13 patients with other LSD, nine patients completed FOT study. Three of them had abnormally high Rrs5 (a patient with Gaucher disease type I had Rrs5 z-score of 2.19, a patient with Niemann-Pick disease type C had Rrs5 z-score of 3.87 and a patient with mucolipidosis type III had Rrs5 z-score of 2.13) Conclusions: Most patients with MPS failed to complete FOT study. Nevertheless, this uncovered a remarkably increased Rrs5 patients with LSD