According to 2019 research published in the NCBI, the ear disease otitis media is an infection of the ear where fluid accumulation is seen in the middle ear. It ranks second in visits to the emergency department, the first being upper respiratory infections in paediatric patients. A 2013 published Laryngoscope article reported that this condition accounts for 15 million paediatrician visits and costs 2.4 billion dollars in terms of care costs per year in the United States!
With more males affected than females, otitis media is an issue around the world. Its incidence is more in children according to Danishyar and Ashurst (2019) the highest incidence of the disease is between the ages of six and twelve months. Estimates pitch the incidence of close to 80% of children suffering from an experience of this condition. In the case of adults, the condition is seen in those who are immunocompromised. The causes range from bacteria (such as Streptococcus pneumoniae, Haemophilus influenza) to viruses (such as respiratory syncytial virus, influenza virus), genetics, passive smoking to even lack of breastfeeding. Treatment with antihistamines and steroids has not been effective and hence, antibiotics are prescribed.
There can be remodelling of the epithelium if acute otitis media occurs several times that causes the ear cells to secrete more mucins and secrete a viscous fluid to cause chronic otitis media. As the mechanisms associated with this remodelling are yet to be analyzed in detail, effective treatment options become narrowed down. This has resulted in relying on repeated surgery to remove the fluid that has accumulated.
In order to study the condition further and design suitable treatment options, in vivo and in vitro models are sought after. The use of animals such as mice represents the former model that allows studying the involvement of various cells. Yet, as these animals are small with small middle ears, the experiments become quite a task. Another challenge is otitis media occurs spontaneously in these animals as opposed to bacterial or viral causes seen in humans.
There are in vitro models such as SV 40 transformed chinchilla middle ear epithelial cells and mouse middle ear epithelial cell line. Yet, the presence of transformation raises the question of how reflective of these models are of the in vivo system. There are changes in the p53 and Rb pathways due to the transformation by the viruses, according to Liu and team in The Journal of Virology that makes the results of assays dubious.
There have been middle ear epithelium primary cultures reported to study the condition. For example, Chen and team reported the primary culture of middle ear epithelial cells from 1-10-year-old children undergoing cochlear implant placement. The 2019-published report in Laryngoscope Investigative Otolaryngology showed that the cultures could secrete the mucin glycoproteins making them suitable to study otitis media. This is one of the goals of research: offering relief to patients especially children who should not be limited due to pain but enjoy their growing years.
Danishyar A, Ashurst JV. Acute Otitis Media. [Updated 2019 Jul 30]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK470332/
Ahmed S, Shapiro NL, Bhattacharyya N. Incremental health care utilization and costs for acute otitis media in children. Laryngoscope 2013;124: 301–305.
Liu X, Dakic A, Chen R, et al. Cell-restricted immortalization by human papillomavirus correlates with telomerase activation and engagement of the hTERT promoter by Myc. The Journal of Virology 2008;82:11568–11576.
Yajun Chen, PhD; Stéphanie Val, PhD; Anna Krueger, MS; Lydia Zhong, BS; Aswini Panigrahi, PhD; Gustavo Nino, MD; Seth Wolf, BS; Diego Preciado, MD, PhD. Human Primary Middle Ear Epithelial Cell Culture: A Novel in vitro Model to Study Otitis Media. Laryngoscope Investigative Otolaryngology. DOI: 10.1002/lio2.319.