Endoscopic and Image Analysis of the Airway in Patients with Mucopolysaccharidosis Type IVA

Adeno-Associated Virus Gene Transfer Ameliorates Progression of Skeletal Lesions in Mucopolysaccharidosis IVA Mice

Mucopolysaccharidosis type IVA (MPS IVA) is an autosomal congenital metabolic lysosomal disease caused by a deficiency of the N-acetyl-galactosamine-6-sulfate sulfatase (GALNS) gene, leading to severe skeletal dysplasia. The available therapeutics for patients with MPS IVA, enzyme replacement therapy and hematopoietic stem cell transplantation, revealed limitations in the impact of skeletal lesions. Our previous study, a significant leap forward in MPS IVA research, showed that liver-targeted adeno-associated virus (AAV) gene transfer of human GALNS (hGALNS) restored GALNS enzymatic activity in blood and multiple tissues and partially improved the aberrant accumulation of storage materials. This promising approach was further validated in our current study, where we delivered AAV8 vectors expressing hGALNS, under the control of a liver-specific or ubiquitous promoter, into MPS IVA murine disease models. The results were highly encouraging, with both AAV8 vectors leading to supraphysiological enzymatic activity in plasma and improved cytoplasmic vacuolization of chondrocytes in bone lesions of MPS IVA mice. Notably, the ubiquitous promoter constructs, a potential game-changer, resulted in significantly greater enzyme activity levels in bone and improved pathological findings of cartilage lesions in these mice than in a liver-specific one during the 12-week monitoring period, reinforcing the positive outcomes of our research in MPS IVA treatment.

Otorhinolaryngological Problems in Mucopolysaccharidoses: A Review of Common Symptoms in a Rare Disease

BACKGROUND

The mucopolysaccharidoses (MPSs) are very rare lysosomal diseases. MPSs belong to inherited diseases; however, newborns are usually asymptomatic. A deficiency of one of the enzymes, which is responsible for glycosaminoglycan (GAG) catabolism, results in the accumulation of this material. GAGs lead to progressive damage to tissues. More than 90% of patients with MPS suffer from otitis media with effusion or recurrent otitis media, craniofacial dysmorphia, obstructive sleep apnea, different types of hearing loss, and progressive upper and lower airway dysfunction. Patients visit otolaryngologists often before the diagnosis of MPS. Thus, the awareness of symptoms of MPS is crucial for otolaryngologists and pediatricians. The earlier the diagnosis is made, the more effective treatment is. Ineffective or delayed treatment leads to premature death. Two principal treatments for MPS are currently available: hematopoietic stem cell transplantation (HSCT) and enzyme replacement therapy (ERT). In recent years, there has been a growing interest in gene therapy as a potential treatment for patients with MPS. Mortality in patients with MPS typically occurs during childhood and early adolescence as a consequence of upper and lower respiratory diseases.

METHODS

This systematic review is based on papers available in the following scientific databases: MEDLINE (via PubMed), Web of Science, Scopus, and the Cochrane Library.

RESULTS

After screening, 72 articles met our inclusion criteria.

CONCLUSIONS

It is of paramount importance that otolaryngologists are involved in this field. This narrative review examines and synthesizes the otolaryngologic issues encountered in patients with MPS.

Airway management of a child with mucopolysaccharidosis undergoing cervical spine surgery: A case report

"Mucopolysaccharidosis" (MPS) is a rare, autosomal recessive lysosomal storage disease characterized by deficiencies in 11 different lysosomal enzymes involved in the metabolism of glycosaminoglycans (GAGs) leading to its accumulation, the condition which results in anatomic abnormalities and multi-organ dysfunction that increases the risk of anesthesia complications. The patterns of accumulation form the basis of MPS classification into seven types of progressive diseases. Most of the MPS types have facial and oral characteristics that increase the risk of airway management. We are reporting a case of MPS with a challenging airway, an 11-years-old boy diagnosed with MPS type VI with a prominent facial character planned for cervical spine fixation versus decompression, successfully managed with fiberoptic bronchoscopy (FOB) guided by video laryngoscopy (VL).

Partial Obstruction of the Endotracheal Tube by a Part of the Metallic Stylet; Case Report and Review of the Literature

Endotracheal intubation is common in the emergency department, intensive care units, and operating rooms. It involves the insertion of an endotracheal tube (ETT) through the mouth or nose into the trachea to maintain a patent airway and facilitate mechanical ventilation. Using a stylet during intubation can guide the ETT through the vocal cords. However, complications can arise when the stylet is not removed after successful intubation. Herewith, we reported a patient who was two years old and suffered from respiratory failure. However, in the first 12 hours, we observed a foreign body in the trachea, a small end of a metal stylet immediately removed by bronchoscope. This case demonstrates that multiple uses of a stylet, especially by a single user, can result in impaction of the stylet in the ETT during intubation, requiring force when the stylet is withdrawn after intubation, which can result in breakage, shearing, and retention of the stylet or plastic sheath in the lumen of the ETT.