Longitudinal Impact of Pseudomonas aeruginosa Versus Haemophilus influenzae Colonization on Lung Function Decline in Children With Primary Ciliary Dyskinesia.

BACKGROUND

The association of Pseudomonas aeruginosa (PsA) and Haemophilus influenzae (HI) colonization with lung function in children with primary ciliary dyskinesia (PCD) remains insufficiently defined. We aimed to compare spirometric parameters between PsA- and HI-colonized children and evaluate longitudinal changes before, at, and after chronic colonization.

METHODS

This retrospective cohort included patients aged ≥ 5 years with definite or highly probable PCD and chronic PsA or HI colonization. Chronic colonization was defined using repeated sputum cultures over 12 months. Pulmonary function tests were analyzed 1 year before colonization, at colonization, and 1 year after colonization. FEV1, FVC, and FEF25-75 were reported as percent-predicted values and GLI 2012 z-scores. Individual pre-to-after-colonization change scores and bronchiectasis subgroup analyses were performed.

RESULTS

Among 290 patients with PCD, 40 met inclusion criteria: 10 with PsA and 30 with HI colonization. PsA-colonized patients were older at colonization than HI-colonized patients (17 [12-23] vs. 11 [9-15] years, p = 0.011), and bronchiectasis was more frequent in the PsA group (100% vs. 60%, p = 0.019). PsA colonization was associated with lower lung function across several spirometric measures. Both groups showed significant within-group declines in FEV1 and FEF25-75 over time. However, individual pre-to-after-colonization changes in FEV1 and FEF25-75 z-scores did not differ significantly between groups, including in the bronchiectasis subgroup analysis.

CONCLUSIONS

PsA colonization was associated with lower lung function than HI colonization, but not with significantly greater longitudinal decline. These findings suggest that PsA may mark more advanced disease rather than independently accelerating functional loss. Larger prospective studies with non-colonized comparators are needed.