Lung function trajectories in common variable immunodeficiencies: An observational retrospective multicenter study

Area of Science:

• Pulmonology
• Immunology
• Internal Medicine

Background:

• Respiratory disease is a significant cause of illness and death in common variable immunodeficiencies (CVIDs).
• Lung function trajectories in CVIDs are not well understood, necessitating further investigation.

Purpose of the Study:

• To determine lung physiology measurements in patients with CVIDs.
• To analyze the temporal trajectory of lung function in CVIDs.
• To investigate the association between lung function and clinical/immunologic parameters in CVIDs.

Main Methods:

• Retrospective analysis of longitudinal pulmonary function tests (PFTs) and chest CT scans from 185 CVID patients across 5 Italian centers.
• PFTs were standardized using the European Respiratory Society/American Thoracic Society 2021 guidelines, expressing results as percentiles within a healthy population's normal distribution.
• Investigated associations between lung function parameters (FEV1, FVC) and clinical/immunologic factors, including switched-memory B cell counts.

Main Results:

• The majority of CVID patients exhibited lung volumes in the lower third of the normal distribution; 23% had FEV1 < lower limit of normal (LLN) and 21% had FVC < LLN.
• Low switched-memory B cells (<2%) were significantly associated with reduced FEV1 (OR 7.58) and FVC (OR 3.55).
• In patients with at least 5 years of PFT data, the annual decline in FEV1 (25.6 mL/year) and FVC (15.6 mL/year) did not differ significantly from predicted rates.

Conclusions:

• Most patients with CVIDs present with lung volumes below the median of healthy individuals.
• The rate of lung function decline in CVID patients is not accelerated post-diagnosis, suggesting a stable disease course in terms of pulmonary function.
• Identifying immunologic markers like switched-memory B cells may help predict lung function impairment in CVIDs.