Persistent Nasal Inflammation 5 Months after Acute Anosmia in Patients with COVID-19

COVID-19 and anosmia: The story so far

OBJECTIVES

The pandemic has affected over 182 million coronavirus disease 2019 (COVID-19) cases worldwide. Accumulated evidence indicates that anosmia is one of the significant characteristics of COVID-19 with a high prevalence. However, many aspects of COVID-19-induced anosmia are still far from being fully understood. The purpose of this review is to summarize recent developments in COVID-19-induced anosmia to increase awareness of the condition.

METHODS

A literature search was carried out using the PubMed, Embase, Web of Science, and Scopus. We reviewed the latest literature on COVID-19-induced anosmia, including mechanisms of pathogenesis, olfactory testing, anosmia as predictive tool, pathological examinations, imaging findings, affected factors, co-existing diseases, treatments, prognosis, hypothesis theories, and future directions.

RESULTS

The possible pathogenesis of COVID-19-induced anosmia may involve inflammation of the olfactory clefts and damage to the olfactory epithelium or olfactory central nervous system by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The D614G spike variant may also play a role in the increased number of anosmia patients. Anosmia may also be an essential indicator of COVID-19 spread and an early indicator of the effectiveness of political decisions. The occurrence and development of COVID-19-induced anosmia may be influenced by smoking behaviors and underlying diseases such as type 2 diabetes, gastroesophageal disorders, and rhinitis. Most patients with COVID-19-induced anosmia can fully or partially recover their olfactory function for varying durations. COVID-19-induced anosmia can be treated with various approaches such as glucocorticoids and olfactory training.

CONCLUSION

Anosmia is one of the main features of COVID-19 and the underlying disease of the patient may also influence its occurrence and development. The possible pathogenesis of COVID-19-induced anosmia is very complicated, which may involve inflammation of the olfactory clefts and damage to the olfactory epithelium or olfactory central nervous system.

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

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.

Distal Lung Inflammation Assessed by Alveolar Concentration of Nitric Oxide Is an Individualised Biomarker of Severe COVID-19 Pneumonia

Pulmonary sequelae as assessed by pulmonary function tests (PFTs) are often reported in patients infected by SARS-CoV-2 during the post-COVID-19 period. Little is known, however, about the status of pulmonary inflammation during clinical recovery after patients’ discharge from the hospitals. We prospectively measured PFTs coupled with the exhaled nitric oxide (NO) stemming from the proximal airways (FeNO) and the distal lung (CaNO) in 169 consecutive patients with varying degrees of the severity of COVID-19 six weeks to one year after acute infection by SARS-CoV-2. The proportions of patients with abnormal PFTs, defined as the presence of either obstructive/restrictive patterns or impaired lung gas transfer, or both, increased with the severity of the initial lung disease (15, 30, and 52% in patients with mild, moderate, and severe COVID-19). FeNO values remained within normal ranges and did not differ between the three groups of patients. CaNO, however, was significantly higher in patients with severe or critical COVID-19, compared with patients with milder forms of the disease. There was also an inverse relationship between CaNO and DLCO. We conclude that the residual inflammation of the distal lung is still present in the post-COVID-19 follow-up period, in particular, in those patients with an initially severe form of COVID-19. This long-lasting alveolar inflammation might contribute to the long-term development of pulmonary fibrosis and warrants the regular monitoring of exhaled NO together with PFTs in patients with COVID-19.

Nasal nitric oxide is decreased in acute mild COVID-19 and related to viral load

Gaseous nitric oxide levels from the lungs (FeNO) and from the nose (nNO) have been demonstrated to react to acute infection or influenza vaccination. There are no published data on nNO levels during acute COVID-19, but normal levels of FeNO have been reported in one study. Our aim was to assess if acute mild COVID-19 alters nasal or bronchial NO output at the time of acute infection and at a 2-month follow up, and if this is related to symptoms or viral load. This study included 82 subjects with mild acute airway infection who did not need hospitalisation: 43 cases (RT-PCR-positive for SARS-CoV-2 in routine testing from nasopharynx) and 39 age- (+/- 5 years) and gender-matched controls (RT-PCR-negative for SARS-CoV-2). During acute infection, the cases had lower nNO compared to controls (526 [345-688] vs. 773 [677-929] ppb; p<0.001), but after two months, there was no significant difference between the groups (766 [597-965] vs. 893 [739-1066] ppb; p=0.162). There was no difference in FeNO between the groups at either of the visits. Nasal NO correlated with the cycle threshold (Ct) value of the nasopharyngeal RT-PCR test for SARS-CoV-2 (Spearman's rs=0.550; p<0.001), that is, nNO was lower with a higher viral load. Nasal NO output was decreased in acute COVID-19 in relation to higher viral load, suggesting that the type and intensity of inflammatory response affects the release of NO from airway mucosa. In these subjects without significant lower airway involvement, there were no clinically relevant findings regarding FeNO.

Allergic Rhinosinusitis and Airway Diseases

The concept of united airway disease interaction, which comprises chronic rhinosinusitis and other lower airway disorders such as asthma, has been recognized for over a decade [...]

Whole-Body Cryotherapy as an Innovative Treatment for COVID 19-Induced Anosmia-Hyposmia: A Feasibility Study

The article entitled, "Whole-Body Cryotherapy as an Innovative Treatment for COVID 19-Induced Anosmia-Hyposmia: A Feasibility Study," by Legrand FD, Polidori G, Beaumont F, Bouchet B, Morin A, Derruau S, and Brenet E (Epub ahead of print Jan 13, 2022; DOI: 10.1089/jicm.2021.0254) is officially retracted at the request of the authors. This request came after the paper had undergone full peer review, three rounds of revisions, acceptance, page proofs, and ultimately, online publication. The Methods section of the published paper states that the study had "secured University ethics clearance…"¹ but the authors explained that, "after re-discussion and internal reassessment, it appears clearly that this study required, according to French law, the approval of a specific committee known as the '[C]ommittee for the [P]rotection of [P]ersons (CPP)' and not a simple ethical agreement. For this reason, [we] request, in good faith, that the article be retracted. We apologize for this delay in taking a position, but this study gave rise to a re-discussion with our peers of the methodology which led us to realize our error 'a posteriori.'" The authors' respective institutions have been notified by the publisher. Journal of Integrative and Complementary Medicine is committed to upholding the rigors of scientific publishing and the veracity of the literature. Reference 1. Legrand FD, Polidori G, Beaumont F, et al. Whole-body cryotherapy as an innovative treatment for COVID 19-induced anosmia-hyposmia: a feasibility study. Epub ahead of print Jan 13, 2022; DOI: 10.1089/jicm.2021.0254.

Post-sequelae one year after hospital discharge among older COVID-19 patients: a multi-center prospective cohort study

Background

To systematically evaluate the prevalence of post-sequelae and chronic obstructive pulmonary disease assessment test (CAT) scoring one year after hospital discharge among older COVID-19 patients, as well as potential risk factors.

Methods

A multi-center prospective cohort study involving 1,233 eligible older COVID-19 patients was conducted. All patients were followed-up between Mar 1, 2021 and Mar 20, 2021. CAT scoring was adopted to measure symptom burden in COVID-19 patients.

Results

Of the 1233 eligible cases, 630 (51.1%) reported at least one sequelae. The top six post-sequelae included fatigue (32.4%), sweating (20.0%), chest tightness (15.8%), anxiety (11.4%), myalgia (9.0%), and cough (5.8%). Severe patients had significantly higher percentage of fatigue, sweating, chest tightness, myalgia, and cough (P<0.05), while anxiety was universal in all subjects. Sweating, anxiety, palpitation, edema of lower limbs, smell reduction, and taste change were emerging sequelae. Disease severity during hospitalization (OR: 1.46, 95% CI: 1.15–1.84, P = 0.002), and follow-up time (OR: 0.71, 95% CI: 0.50–0.99, P = 0.043) were independently associated with risk of post-sequelae, while disease severity during hospitalization was significantly associated with increased risk of emerging sequelae (OR: 1.33, 95% CI: 1.03–1.71, P = 0.029). The median of CAT score was 2 (0–5) in all patients, and a total of 120 patients (9.7%) had CAT scores ≥10. Disease severity during hospitalization (OR: 1.81, 95% CI: 1.23–2.67, P = 0.003) and age (OR: 1.07, 95% CI: 1.04–1.09, P<0.001) were significantly associated with increased risk of CAT scores ≥10.

Conclusions

While the dramatic decline in the prevalence rate of persistent symptoms is reassuring, new sequelae among older COVID-19 patients cannot be ignored. Disease severity during hospitalization, age, and follow-up time contributed to the risk of post-sequelae and CAT scoring one year after hospital discharge among older COVID-19 patients. Our study provides valuable clues for long-term post-sequelae of the older COVID-19 patients, as well as their risk factors.