Flexible bronchoscopy provided real-time dynamic imaging of the airways of 5 individuals with late-onset Pompe disease (LOPD), according to a study published in Pediatric Pulmonology.
These investigative findings indicated worsening airway abnormality progression and pulmonary complications despite long-term treatment with the enzyme replacement therapy alglucosidase alfa (Myozyme®).
The complications and abnormalities included a compromised oropharynx, tracheal and bronchial malacia, sleep hypoventilation disorder, difficulties with sputum clearance leading to respiratory infections, pulmonary hypertension, daytime dyspnea, mild facial abnormalities, and airway narrowing. One of the 5 patients had severe airway narrowing that required placement of 2 stents using flexible bronchoscopy.
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“Respiratory compromise is a critical prognostic factor in patients with LOPD, even with regular Myozyme treatment,” the authors affirmed. “According to this study, our long-term treated LOPD patients with milder type of Pompe disease, after years of Myozyme treatment, presented with even worse airway abnormalities compared to [those with infantile-onset Pompe disease in a previous study] in our series.”
Read more about Pompe disease differential diagnosis
The researchers attributed this finding to later diagnosis in those with LOPD because they were born prior to the newborn screening program. Therefore, the lack of immediate diagnosis delayed enzyme replacement treatment. The researchers speculated that this potentially caused excessive glycogen buildup, resulting in poorer efficacy of alglucosidase alfa for airway treatment.
The investigators enrolled 5 individuals (2 girls and 3 boys) with LOPD, all of whom missed obtaining early newborn diagnoses due to birth prior to implementation of the newborn screening program in 2008 at Taipei Veterans General Hospital in Taiwan. These individuals had an average age range of 12.7 ± 2.1 years at the time of diagnosis. The mean follow-up timeframe was 71 ± 27.5 months.
The researchers utilized flexible bronchoscopy to regularly evaluate the progression of airway abnormalities and pulmonary complications in these individuals who received alglucosidase alfa enzyme replacement therapy biweekly since 2012. This procedure involved intravenous sedation, continuous vitals monitoring, and recording and assessment of images by a pediatric pulmonologist.
The investigators collected additional data, including annual pulmonary function tests and polysomnography tests. They noted longitudinal changes in forced vital capacity and progression of obstructive sleep apnea as supplementary functional outcome measures.
Reference
Wang T-H, Soong W-J, Niu D-M, et al. Airway abnormalities and pulmonary complications in long-term treated late-onset Pompe disease: diagnostic and interventional by flexible bronchoscopy. Pediatr Pulmonol. Published online October 13, 2021. doi:10.1002/ppul.25725
