Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2025 Jul;14(7):2861-2866.
doi: 10.4103/jfmpc.jfmpc_185_25. Epub 2025 Jul 21.

COVID-19-associated changes in nasal mucosa: Insights from inflammatory and epithelial cell profiling

Pranav Donkada  1 , B Vishnu  1 , Senthil Murugan  2 , Kishore Sesham  2 , Satvinder S Bakshi  3 , Vinothkumar Kalidoss  4 , Yuvaraj Maria Francis  5 , Sankaran Ponnusamy Kasirajan  2
Affiliations

COVID-19-associated changes in nasal mucosa: Insights from inflammatory and epithelial cell profiling

Pranav Donkada et al. J Family Med Prim Care. 2025 Jul.

Abstract

Background: Coronavirus disease of 2019 (COVID-19), caused by Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), primarily affects nasal cavities by binding its spike proteins to angiotensin-converting enzyme 2 (ACE2) receptors. This study aimed to assess inflammatory and epithelial cell counts and determine their ratios in exfoliated nasal mucosal cells of COVID-19 suspected patients.

Methodology: This cross-sectional study was conducted at All India Institute of Medical Sciences (AIIMS), Mangalagiri, from August to October 2022, involving 75 COVID-19 suspected patients. Nasal smears were collected, stained with Papanicolaou test (PAP), and analyzed for inflammatory and epithelial cell counts. Participants were grouped as COVID-19 positive and negative based on Real Time Polymerase Chain Reaction (RT-PCR) results. Genotoxicity factors were evaluated using mean and standard deviation values.

Results: In COVID-19 positive individuals, mean cell counts for neutrophils, eosinophils, lymphocytes, mast cells, macrophages, and epithelial cells were 42.08, 6.68, 4.48, 0.84, 0.12, and 45.80, respectively. In COVID-19 negative patients, the corresponding values were 38.08, 13.76, 11.12, 2.66, 0.22, and 34.16. The inflammatory ratios for neutrophils to eosinophils and neutrophils to lymphocytes in COVID-19 positive individuals were 7.30 and 14.06, respectively. SARS-CoV-2 infection resulted in elevated neutrophil and epithelial cell counts and decreased eosinophil, lymphocyte, mast cell, and macrophage count.

Conclusions: SARS-CoV-2 exhibits unique immunological alterations in nasal mucosa. The inflammatory ratios of neutrophils-to-eosinophils and neutrophils-to-lymphocytes may serve as reliable diagnostic markers for COVID-19.

Keywords: COVID-19; SARS-CoV-2; epithelial cells; inflammation; nasal mucosa.

PubMed Disclaimer

Conflict of interest statement

There are no competing conflicts of interest to declare among the authors.

Figures

Figure 1
Figure 1
Epithelial cells and neutrophils in COVID-19 positive patients
Figure 2
Figure 2
Epithelial cells and eosinophils in COVID-19 negative patients
Figure 3
Figure 3
Basophils with granules and lymphocytes in COVID-19 negative patients
Figure 4
Figure 4
Epithelial cells with loss of cilia and intranuclear halo in COVID-19 positive patients
Figure 5
Figure 5
Mechanism of nasal cytological changes in COVID-19 patients
See this image and copyright information in PMC

Similar articles

  • The effect of sample site and collection procedure on identification of SARS-CoV-2 infection.
    Davenport C, Arevalo-Rodriguez I, Mateos-Haro M, Berhane S, Dinnes J, Spijker R, Buitrago-Garcia D, Ciapponi A, Takwoingi Y, Deeks JJ, Emperador D, Leeflang MMG, Van den Bruel A; Cochrane COVID-19 Diagnostic Test Accuracy Group. Davenport C, et al. Cochrane Database Syst Rev. 2024 Dec 16;12(12):CD014780. doi: 10.1002/14651858.CD014780. Cochrane Database Syst Rev. 2024. PMID: 39679851 Free PMC article.
  • Laboratory-based molecular test alternatives to RT-PCR for the diagnosis of SARS-CoV-2 infection.
    Arevalo-Rodriguez I, Mateos-Haro M, Dinnes J, Ciapponi A, Davenport C, Buitrago-Garcia D, Bennouna-Dalero T, Roqué-Figuls M, Van den Bruel A, von Eije KJ, Emperador D, Hooft L, Spijker R, Leeflang MM, Takwoingi Y, Deeks JJ. Arevalo-Rodriguez I, et al. Cochrane Database Syst Rev. 2024 Oct 14;10(10):CD015618. doi: 10.1002/14651858.CD015618. Cochrane Database Syst Rev. 2024. PMID: 39400904
  • Rapid, point-of-care antigen tests for diagnosis of SARS-CoV-2 infection.
    Dinnes J, Sharma P, Berhane S, van Wyk SS, Nyaaba N, Domen J, Taylor M, Cunningham J, Davenport C, Dittrich S, Emperador D, Hooft L, Leeflang MM, McInnes MD, Spijker R, Verbakel JY, Takwoingi Y, Taylor-Phillips S, Van den Bruel A, Deeks JJ; Cochrane COVID-19 Diagnostic Test Accuracy Group. Dinnes J, et al. Cochrane Database Syst Rev. 2022 Jul 22;7(7):CD013705. doi: 10.1002/14651858.CD013705.pub3. Cochrane Database Syst Rev. 2022. PMID: 35866452 Free PMC article.
  • Signs and symptoms to determine if a patient presenting in primary care or hospital outpatient settings has COVID-19.
    Struyf T, Deeks JJ, Dinnes J, Takwoingi Y, Davenport C, Leeflang MM, Spijker R, Hooft L, Emperador D, Domen J, Tans A, Janssens S, Wickramasinghe D, Lannoy V, Horn SRA, Van den Bruel A; Cochrane COVID-19 Diagnostic Test Accuracy Group. Struyf T, et al. Cochrane Database Syst Rev. 2022 May 20;5(5):CD013665. doi: 10.1002/14651858.CD013665.pub3. Cochrane Database Syst Rev. 2022. PMID: 35593186 Free PMC article.
  • Antibody tests for identification of current and past infection with SARS-CoV-2.
    Fox T, Geppert J, Dinnes J, Scandrett K, Bigio J, Sulis G, Hettiarachchi D, Mathangasinghe Y, Weeratunga P, Wickramasinghe D, Bergman H, Buckley BS, Probyn K, Sguassero Y, Davenport C, Cunningham J, Dittrich S, Emperador D, Hooft L, Leeflang MM, McInnes MD, Spijker R, Struyf T, Van den Bruel A, Verbakel JY, Takwoingi Y, Taylor-Phillips S, Deeks JJ; Cochrane COVID-19 Diagnostic Test Accuracy Group. Fox T, et al. Cochrane Database Syst Rev. 2022 Nov 17;11(11):CD013652. doi: 10.1002/14651858.CD013652.pub2. Cochrane Database Syst Rev. 2022. PMID: 36394900 Free PMC article.
See all similar articles

References

    1. World Health Organization. WHO Coronavirus (COVID-19) dashboard [Internet] 2022. [[Last accessed on 2022 Aug 12]]. Available from: https://covid19.who.int/
    1. Zhou P, Yang XL, Wang XG, Hu B, Zhang L, Zhang W, et al. A pneumonia outbreak associated with a new coronavirus of probable bat origin. Nature. 2020;579:270–3. - PMC - PubMed
    1. Nakamura T, Hasegawa-Nakamura K, Sakoda K, Matsuyama T, Noguchi K. Involvement of angiotensin II type 1 receptors in interleukin-1?-induced interleukin-6 production in human gingival fibroblasts. Eur J Oral Sci. 2011;119:345–51. - PubMed
    1. Drummond RL, Rhoden CR, Lubianca Neto JF, Fleck AD, Padoin RC, Amantéa SL. Micronucleus count in nasal epithelial cells from patients with chronic rhinosinusitis and polyps. Braz J Otorhinolaryngol. 2020;86:743–7. - PMC - PubMed
    1. Pattemore PK, Johnston SL, Bardin PG. Viruses as precipitants of asthma symptoms. I. Epidemiology. Clin Exp Allergy. 1992;22:325–36. - PMC - PubMed

LinkOut - more resources