Mucopolysaccharidoses and laryngeal, tracheal and bronchial disease: Type-specific abnormalities and long-term implications

Airway complications are among the most common early and lethal manifestations of mucopolysaccharidoses (MPS). Not much is known, however, on the anatomical characteristics of the airways in this patient group, the exact sites of involvement and variability between the different subtypes of MPS. We evaluated the lower airways of 32 MPS patients (23 males, 9 females), divided in the following MPS types: I(6), II(10), III(2), IVA(3) and VI(11). Exams were performed with a flexible 3,5mm bronchoscope, trespassing the glottis and viewing the anatomy of the lower airways. Two MPSII patients transplanted before 3months with normal airways were excluded from the analysis. Laryngeal deformities were present in 37% (edema in aritenoids, thickening of false vocal cords, post-cricoid edema). 33% presented with laringomalacia (13% severe). Epiglottis was thickened in 57%, 13% with total loss of organ support. Tracheal deformities were present in 53%, most with diffuse involvement. Abnormal anatomy of bronchi was observed in 13,3%. 4 patients (3 MPSII and 1 MPSVI) presented endobronchial obstruction secondary to possible GAG deposits and 2 MPSII died of respiratory complications. Abnormalities varied among MPS types: while the MPSI and II had supraglottic redundancy and tracheomalacia, no laryngeal disease was observed in the MPS-IVA and VI group. On the other hand, all MPSIVA, 75% of the MPSII, 64% of the MPSVI and 50% of the MPSI had tracheobronchial deformity, being the MPSIVA group the most striking and severe. Significant and impressive involvement of the trachea and bronchi architecture varied according to MPS subtype, severity of the phenotype and age of the patient. There was a strong correlation between airway damage, patient age and duration of disease, despite adequate ERT. On the other hand, the introduction of ERT at a very young age seemed to correlate with slightly milder lower airway disease.