Antibiotic Eradication of P. Aeruginosa Improves Long Term Lung Function in CF

Less long-term deterioration in FEV1 occurred in patients with cystic fibrosis whose P. aeruginosa infection during childhood had been successfully eradicated by AET.

Antibiotic eradication therapy (AET) against Pseudomonas aeruginosa improves lung function trajectory in patients with cystic fibrosis (CF), according to retrospective analysis findings published in Journal of Cystic Fibrosis.

Previous research has not assessed how CF is affected in the long-term by AET, the standard of care for early P. aeruginosa infection, a common pathogen of CF lung disease. P. aeruginosa early infection acts as a major predictor of morbidity and mortality in young children with CF. Researchers sought to evaluate the effect of AET on long-term pulmonary trajectories among pediatric CF patients. The primary endpoint was absolute FEV1 decline over time.

The investigators conducted a 20-year retrospective study analyzing data on children with CF seen at 2 hospitals in Toronto, Canada, included in the Toronto CF Database from 1998 to 2018.  The study sample included 205 CF patients (median age at first infection 9.6 [IQR 5.6-14.6] years; 48% girls). Data included patients’ pulmonary function tests, medications, and microbiology, supplemented with systematic review of health records. Included patients were less than 18 years of age at entry with a confirmed CF diagnosis, had pulmonary function measurements for a minimum of 10 years, and were P. aeruginosa-free for at least 1 year.

Patient data was analyzed for 4 different time points — ages 10, 15, 20, and 25 years — with patients divided into 3 categories based on their experience with P. aeruginosa at each time point. Patients were categorized as: Never (those who, at that time point, had never had P. aeruginosa infection isolated from a respiratory tract sample), Eradicated (those with P. aeruginosa infection whose infection cleared subsequent to AET treatment), or Chronic (those whose P. aeruginosa infection was treated with AET but never cleared). Researchers used mixed-effects linear regression models to account for the repeated lung function measurements per patient over time.

The analyses indicated that FEV1 annual lung function decline in the Eradication group was -1.11% predicted/year (95% CI, -1.18 to -1.04) — a level of decline that was significantly less than in the Chronic group, in which FEV1 annual lung function decline was -1.57% predicted/year (95% CI, -1.64 to -1.50) (P <.001). In the Never group, FEV1 annual lung function decline was −0.77% per year (95% CI, -0.94 to -0.60%).

Researchers concluded that “successful P. aeruginosa eradication therapy is associated with improved long term lung function, supporting the current standard of care in the management of CF patients.” They added “AET can not only result in improved microbiological outcomes, but clinical outcomes as well.” Study limitations include its retrospective nature.


Casaredi IG, Shaw M, Waters V, Seeto R, Blanchard A, Ratjen F. Impact of antibiotic eradication therapy of Pseudomonas aeruginosa on long term lung function in cystic fibrosis. J Cyst Fibros. Published online August 19, 2022. doi:10.1016/j.jcf.2022.08.007