A study whose findings were published in the journal Nature explored nasal polyps and gained new insights into this condition as well as its potential to cause other problems such as asthma and allergies. For the purpose of the study, the scientists obtained samples from 12 patients with nasal polyps or other sinus conditions. They collected 18,036 cells in total. Then, obtained samples were compared to nasal scrapings from healthy subjects.
The results showed that epithelial progenitor cells had been entirely remodeled in polyp samples. What’s more, these cells were altered permanently. One of the biggest surprises of the study was that even when removed from the tissue and grown in a laboratory, the resulting cells had genetic differences. The change in basic tissue architecture at the genetic level was due to inflammation associated with nasal polyps. This highlighted the role of inflammation in nasal polyps and how important it is to tackle this, for example by consuming anti-inflammatory foods. Read more: Turmeric for shrinking nasal polyps.
The study found that decreased epithelial diversity stemming from the functional shift in basal cells is a primary characteristic of type 2 immune-mediated barrier tissue dysfunction. The results demonstrate that epithelial stem cells contribute to the persistence of human disease by acting as repositories for allergic memories[i]. The importance of this research was that it shed light on nasal polyps and its role in diseases such as allergic reactions, asthma, and others.
The relationship between nasal polyps and allergies or asthma requires more research. Current evidence shows that indeed nasal polyps can contribute to these conditions. For instance, the European Respiratory Journal published a study which found that severe asthma with nasal polyps represents the most serious phenotype of asthma and could be a result of a distinct underlying mechanism or endotype[ii] which needs to be further studied.
When it comes to the impact on nasal polyps on the severity of allergies, the current evidence is inconclusive. One older study showed that seasonal allergen exposure in patients with nasal polyps does not enhance the level of expression of the disease[iii].
Nasal polyps are associated with chronic inflammation and conditions such as allergies and asthma, but according to the American College of Allergy, Asthma, and Immunology, they are not the cause of the latter[iv]. Indeed, evidence shows that nasal polyps and asthma do not occur, i.e., develop simultaneously. A clinical history of nasal polyps usually precedes asthma, and up to 45% of patients with nasal polyps will develop adult-onset asthma[v].
It is worth mentioning that asthma and allergies (more precisely allergic fungal sinusitis) are risk factors for the development of nasal polyps. Any condition that triggers long-term inflammation could lead to the development of nasal polyps, while these tiny growths can cause complications such as worsened asthma flare-ups, sinus infections, and obstructive sleep apnea[vi]. Read more: Nasal Polyps shrinkage diet.
The relationship between nasal polyps and allergies or asthma is evident but still poorly explored. Further studies on this subject are crucial to elucidate all the mechanisms associated with these conditions as there could be a two-way relationship between them. Current evidence on this subject is relatively scarce and inconclusive.
Written by Manuel Richards, health researcher and author of Nasal Polyps Treatment Miracle.
[i] Barrett NA, Shalek AK, Ordovas-Montanes J, et al. Allergic inflammatory memory in human respiratory epithelial progenitor cells. Nature 2018 Aug;560:649-654, DOI: https://doi.org/10.1038/s41586-018-0449-8
[ii] Castillo JA, Plaza V, Rodrigo G, et al. Asthma with nasal polyps: The “severe” phenotype? European Respiratory Journal 2014 Sep;44(Suppl 58):4118 https://erj.ersjournals.com/content/44/Suppl_58/P4118
[iii] Keith PK, Conway M, Evans S, et al. Nasal polyps: Effects of seasonal allergen exposure. The Journal of Allergy and Clinical Immunology 1994 Mar;93(3):567-574 DOI: https://doi.org/10.1016/S0091-6749(94)70068-0
[iv] How are nasal polyps related to asthma and sinusitis. American College of Allergy, Asthma, and Immunology https://acaai.org/resources/connect/ask-allergist/how-are-nasal-polyps-related-asthma-and-sinusitis
[v] Wu D, Bleier BS, Wei Y. Progression from nasal polyps to adult-onset asthma: a different process from the atopic march? Rhinology Online 2018 Mar;(1):22-29, DOI: https://doi.org/104193/RHINOL/18.006
[vi] Nasal polyps. Mayo Clinic https://www.mayoclinic.org/diseases-conditions/nasal-polyps/symptoms-causes/syc-20351888