Chronic rhinosinusitis increases the risk of non-cystic fibrosis bronchiectasis

Published online August 4, 2024

The unified airway hypothesis suggests that not only do the diseases of the upper and lower airways share an anatomic connection but that both are manifestations of shared inflammatory processes. Cross-sectional studies have shown a high prevalence of chronic rhinosinusitis (CRS) in patients with bronchiectasis and vice versa. A subsequent case-control study of patients with and without bronchiectasis performed in a general population in Pennsylvania showed a strong association between CRS and non-cystic fibrosis bronchiectasis, and CRS was identified before bronchiectasis. Assessing whether CRS is a risk factor for bronchiectasis is important to future work investigating the prevention and treatment of lower airway disease in patients with CRS.

In a recent study published in The Journal of Allergy and Clinical Immunology: In Practice, Kim et al. performed a retrospective cohort study utilizing Northwestern’s Enterprise Data Warehouse to determine whether patients with CRS have an increased risk of developing bronchiectasis. Patients with CRS without underlying bronchiectasis were identified from January 2006 to December 2015. Then, only patients with at least one chest computed tomography (CT) performed between January 2006 and May 2022 were eligible for inclusion in the study. A control group of patients without CRS who had chest CT scans was also included for comparison. Following a previously published algorithm that achieved a control positive predictive value of 100% for CRS, patients with underlying lower airway disease including asthma and chronic obstructive pulmonary disease (COPD) were excluded from the control group. Thus, the authors further classified the CRS group into two separate cohorts based on the presence or absence of asthma or COPD. Cohort 1 included patients with CRS without asthma or COPD. Cohort 2 included patients with CRS with asthma or COPD. For both the CRS and control groups, bronchiectasis was identified by a text word search for “bronchiectasis” in chest CT radiology reports.  

There were 1594 patients in the CRS group, and 7992 patients in the control (no CRS) group. Among the CRS group, there were 863 patients in Cohort 1 (CRS without asthma or COPD) and 731 patients in Cohort 2 (CRS with asthma or COPD). The study found that the odds of developing bronchiectasis were significantly higher in patients with CRS compared to patients without CRS (OR 1.63 [1.34-1.99]). When comparing Cohort 1 to the control group, the odds of bronchiectasis was found to be approximately 35% higher in Cohort 1 (OR 1.34 [1.02-1.76]). The comparison between Cohort 2 and the control group highlighted a substantially increased risk of bronchiectasis in Cohort 2 (OR 1.98 [1.53-2.55]), indicating the significant impact of CRS and concurrent asthma or COPD on the development of bronchiectasis. After adjusting for autoimmune diseases, immunodeficiencies, and allergic bronchopulmonary aspergillosis (ABPA), which are associated with bronchiectasis, the OR for Cohort 1 versus the control group was no longer statistically significant (1.22 [0.92-1.61], p=0.165), although patterns of the associations in CRS patients remained. The adjusted OR for Cohort 2 versus the control group was 1.78 [1.37-2.31]. The authors also observed a notable association between these comorbidities (autoimmune diseases, immunodeficiencies, and ABPA) and bronchiectasis in patients with CRS (OR 2.30 [1.82 – 2.01]). For patients with CRS, the average time to development of bronchiectasis was 6.01 years (SD=4.16), with 86.2% of patients developing bronchiectasis 2 or more years after their initial diagnosis of CRS. The authors concluded that patients with CRS, especially those with comorbid asthma or COPD, have a much higher likelihood of developing bronchiectasis. CRS patients with persistent lower airway symptoms should be screened for bronchiectasis, especially in the presence of comorbidities such as asthma, COPD, autoimmune diseases, immunodeficiencies, and ABPA.

The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.

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