A recent study investigates the role of the epipharynx in long COVID, particularly focusing on the activation of SARS-CoV-2 signaling pathways and the potential benefits of epipharyngeal abrasive therapy (EAT) as a treatment.

Long COVID, which manifests through symptoms like chronic fatigue and cough, affects many individuals following their initial recovery from COVID-19, with chronic epipharyngitis potentially exacerbating these symptoms.

EAT, developed in Japan, is an outpatient treatment that involves nebulizing the inflamed epipharynx with a zinc chloride solution to reduce inflammation and alleviate symptoms.

In the study, three long COVID patients underwent EAT, receiving weekly treatments over three months, which resulted in significant symptom improvement and reduced inflammation scores.

Histological examinations revealed improvements in the inflamed ciliated epithelium, and levels of proinflammatory cytokines showed significant declines, indicating the anti-inflammatory effects of EAT.

EAT also led to decreased levels of residual SARS-CoV-2 RNA in the epipharynx of most patients, suggesting a potential mechanism for symptom relief.

The research indicates that the epipharynx, which is rich in proteins that facilitate SARS-CoV-2 entry, plays a significant role in chronic inflammation associated with long COVID symptoms.

Post-treatment assessments indicated significant reductions in viral RNA and symptom relief, as measured by the Visual Analog Scale (VAS), highlighting EAT's effectiveness.

The treatment was shown to suppress T-cell receptor signaling pathways and reduce the expression of inflammatory cytokines such as IL-6 and TNF-α, which are associated with long COVID symptoms.

Using Visium HD technology, the study provided high-resolution insights into gene expression changes in the epipharynx, revealing ongoing immune response activation in patients even after acute infection had resolved.

Gene expression analyses demonstrated that B cells and plasmacytoid dendritic cells in the epipharynx exhibited heightened immune responses, indicating chronic inflammation and immune activation.

Future research with a larger sample size is necessary to further validate the effectiveness of EAT and comprehensively explore its impact on long COVID symptoms.