Immunodeficiency associated bronchiectasis in the European Bronchiectasis Registry (EMBARC)

Introduction: Immunodeficiency is a recognised cause of bronchiectasis but individual cohorts are typically too small to describe the demographics and severity of disease in this group. The EMBARC Registry represents a large dataset to address this. Methods: Data submitted from centres to EMBARC from Jan 2015 to June 2019 was studied. Severity of disease was evaluated using the Bronchiectasis severity index (BSI) and quality of life using the QOL-B. Results: Of the 13512 patients included, 491 (3.6%) patients were reported as having bronchiectasis due to immunodeficiency. The most commonly reported cause entered was common variable immunodeficiency (35.8%). Patients with immunodeficiency had a mean age of 56.5 years (sd 17.3), with moderate severity (median BSI 6, IQR 3-10) and symptomatic impairment (QOL-B 63.5, sd 20.6). During follow-up (mean 3 years) patients with immunodeficiency as the reported aetiology did not have a higher exacerbation frequency compared to idiopathic bronchiectasis – rate ratio 0.90 95% CI 0.78-1.04,p=0.15. Interestingly, patients with immunodeficiency had significantly less severe respiratory symptoms using the QOL-B (difference 3.5 points 95% CI 1.61-5.37,p Conclusion: Immunodeficiency accounts for 3.6% of bronchiectasis cases. Patients have a wide spectrum of severity but on average less severe symptoms compared to patients with other aetiologies.