Is there a correlation between eosinophilic esophagitis and preserved ratio impaired spirometry?

Correlation Between Eosinophilic Esophagitis and Preserved Ratio Impaired Spirometry

There is currently no established correlation between eosinophilic esophagitis (EoE) and preserved ratio impaired spirometry (PRISm) based on the available evidence.

Understanding Eosinophilic Esophagitis (EoE)

EoE is an immune/antigen-driven inflammatory condition characterized by:

• Eosinophil-rich inflammation of the esophagus (≥15 eosinophils per high-power field) 1
• Common symptoms including dysphagia, food impaction, chest pain, and upper abdominal pain in adults 1
• Strong association with atopic conditions including allergic asthma, rhinitis, and eczema 1
• Male predominance (3:1 male to female ratio) 1
• Increasing prevalence worldwide, with estimates rising from 15/100,000 before 2007 to 63/100,000 since 2017 1

Respiratory Manifestations and EoE

While EoE has established associations with various atopic conditions, the current guidelines and research do not specifically address a connection with PRISm. The key points regarding respiratory associations include:

• EoE is frequently associated with other atopic conditions, particularly allergic asthma 1
• Seasonal variation in EoE symptoms has been observed, with flares during pollen season and higher pollen counts, suggesting a potential link to aeroallergen exposure 1
• No specific mention of PRISm or similar pulmonary function abnormalities appears in the major EoE guidelines 1

Preserved Ratio Impaired Spirometry (PRISm)

PRISm is characterized by:

• Reduced FEV1 or FVC with a preserved FEV1/FVC ratio 2
• Prevalence estimated at 17-24% in a spirometry database, higher than previously reported 7-12% 2
• Associated factors include higher body mass index and restrictive lung disease 2
• Smoking is inversely associated with PRISm 2

Potential Mechanistic Links

While direct evidence for a correlation is lacking, several potential mechanisms could theoretically connect these conditions:

1. Shared Inflammatory Pathways: EoE is characterized by TH2-mediated inflammation 3, which is also implicated in certain respiratory conditions.

2. Impaired Esophageal Function: EoE leads to esophageal dysfunction and impaired barrier integrity 4, which could potentially affect respiratory mechanics through altered thoracic compliance or neural pathways.

3. Esophageal Compliance Changes: Studies have shown that EoE patients have reduced esophageal compliance 5, which could theoretically impact respiratory mechanics, though this connection has not been established.

Clinical Implications

For clinicians evaluating patients with either condition:

• Patients with EoE should be assessed for common comorbid atopic conditions, particularly asthma 1
• Persistent dysphagia in EoE patients despite histological remission may warrant oesophageal physiological testing 1
• High-resolution manometry (HRM) can be useful in assessing esophageal body and lower esophageal sphincter function in EoE patients with persistent symptoms 1
• There is no current recommendation to specifically screen EoE patients for PRISm or vice versa

Research Gaps

Several important knowledge gaps exist:

• No studies directly examining pulmonary function tests in EoE patients
• Limited understanding of how esophageal compliance changes might affect respiratory mechanics
• Lack of investigation into shared inflammatory pathways between EoE and PRISm
• Need for studies examining the prevalence of PRISm in EoE patients compared to the general population

In conclusion, while both EoE and PRISm are increasingly recognized conditions with potential for shared pathophysiological mechanisms, current evidence does not support a direct correlation between them. Further research specifically investigating this relationship is needed.