Age of Pseudomonas aeruginosa acquisition and subsequent severity of cystic fibrosis lung disease.

RATIONALE: Pseudomonas aeruginosa (Pa) is associated with poor pulmonary outcomes in cystic fibrosis (CF), but the association between age of Pa infection and severity of subsequent lung disease has not been thoroughly investigated.
OBJECTIVE: Our goal was to determine the association between age of Pa acquisition and subsequent severity of CF lung disease.
METHODS: Case-control study using CF Foundation Registry data of 629 ΔF508 homozygotes with severe and mild lung disease (FEV1 in the lowest and highest quartile of birth cohort, respectively). Multivariate logistic regression was performed to determine the association between age of Pa acquisition and lung disease severity.
RESULTS: Earlier age of Pa infection was strongly associated with increased odds of severe lung disease. For first and persistent Pa, adjusted odds ratios for severe lung disease were 6.5 (95% CI 3.1, 13.7; P < 0.0001) and 11.2 (5.4, 23.1; P < 0.0001), respectively, for subjects with infection before age 5 versus at ≥ 10 years; the association was stronger in females than males.
CONCLUSIONS: Earlier Pa infection, particularly before 5 years of age, is strongly associated with severe CF lung disease later in life. This study is not designed to determine causality; Pa infection may be causing lung injury, or may be a marker of ongoing inflammation and lung damage in young children with CF.