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Case Reports
. 2023 Mar 31;15(4):899.
doi: 10.3390/v15040899.

Persistence of SARS-CoV-2 Antigens in the Nasal Mucosa of Eight Patients with Inflammatory Rhinopathy for over 80 Days following Mild COVID-19 Diagnosis

Juliana Costa Dos Santos  1 , Marjory Ximenes Rabelo  2 , Luana Mattana Sebben  3 , Matheus Vinicius de Souza Carneiro  4 , João Bosco Lopes Botelho  5 , José Cardoso Neto  6 , Anderson Nogueira Barbosa  7 , Diego Monteiro de Carvalho  4   5 , Gemilson Soares Pontes  1   7
Affiliations
Case Reports

Persistence of SARS-CoV-2 Antigens in the Nasal Mucosa of Eight Patients with Inflammatory Rhinopathy for over 80 Days following Mild COVID-19 Diagnosis

Juliana Costa Dos Santos et al. Viruses. .

Abstract

The nasal mucosa is the main gateway for entry, replication and elimination of the SARS-CoV-2 virus, the pathogen that causes severe acute respiratory syndrome (COVID-19). The presence of the virus in the epithelium causes damage to the nasal mucosa and compromises mucociliary clearance. The aim of this study was to investigate the presence of SARS-CoV-2 viral antigens in the nasal mucociliary mucosa of patients with a history of mild COVID-19 and persistent inflammatory rhinopathy. We evaluated eight adults without previous nasal diseases and with a history of COVID-19 and persistent olfactory dysfunction for more than 80 days after diagnosis of SARS-CoV-2 infection. Samples of the nasal mucosa were collected via brushing of the middle nasal concha. The detection of viral antigens was performed using immunofluorescence through confocal microscopy. Viral antigens were detected in the nasal mucosa of all patients. Persistent anosmia was observed in four patients. Our findings suggest that persistent SARS-CoV-2 antigens in the nasal mucosa of mild COVID-19 patients may lead to inflammatory rhinopathy and prolonged or relapsing anosmia. This study sheds light on the potential mechanisms underlying persistent symptoms of COVID-19 and highlights the importance of monitoring patients with persistent anosmia and nasal-related symptoms.

Keywords: COVID-19; nasal mucosa; olfactory dysfunction; rhinopathy.

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Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
Flowchart illustrating the study’s design and the total number of individuals included.
Figure 2
Figure 2
Clinical characteristics of patients complaining of mild post-COVID-19 olfactory disorders. (A) absolute frequency of clinical symptoms observed during application of the clinical-epidemiological questionnaire (A, B, C, D, E, F, G) and otorhinolaryngological physical examination (H, I). The letters inside the circle represent the X-axis and indicate which group each variable belongs to. The lines between the groups represent the Y-axis and indicate the absolute frequency of each variable. (B) Absolute frequency of surgery and previous nasal trauma. * patients’ perception of symptoms.
Figure 3
Figure 3
Nasal mucociliary mucosa of patients complaining of mild post-COVID-19 olfactory dysfunction. Negative control (A); positive control (B); patients (C–E). SARS-CoV-2 S/N proteins, in green; nucleic acid labeling (DAPI), in blue; ciliary structures-tubulin, in red. The “Merge” column shows all overlapping markups. Images (C–E) are representative of samples from 8 patients. The images were selected among a total of 24 images through three replicates. Scale bars represent 25 µm. Arrows indicate viral antigen (nucleocapsid and spike proteins) staining.
See this image and copyright information in PMC

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