Effect of respiratory Achromobacter spp. infection on pulmonary function in patients with cystic fibrosis.

PURPOSE: Cystic fibrosis (CF) patients are susceptible to infection with Achromobacter spp., although its clinical significance remains controversial. The aim of this study was to investigate the clinical impact of infection with Achromobacter spp. in CF patients.

METHODS: CF outpatients with multiple sputum cultures and follow-up lung function tests were assigned to the case group (infected with Achromobacter spp.) or the control group (never infected with Achromobacter spp.) according to the isolation of Achromobacter spp. The Achromobacter spp. group included two subgroups, taking into consideration whether the isolation of Achromobacter spp. was intermittent or chronic. Baseline lung function tests and longitudinal behaviour were examined in relation to Achromobacter spp. status.

RESULTS: A total of 190 CF patients were treated from January 2003 to December 2015 in the CF unit and 21 (11 %) had at least one positive culture for Achromobacter spp. Of these, 11/21 (52.4 %) patients were chronically infected with Achromobacter spp. An analysis of changes during follow-up showed the annual rate of FEV1 decline: -2.3±1.6 % in the Achromobacter spp. group compared to -1.1±0.9 % (P=0.02) in the control group. The chronically infected group also had a significantly greater decline in FEV1 compared to the control group (-2.9±1.9 vs -1.1±0.9; P=0.04). The mean number of annual pulmonary exacerbations during the study period was significantly higher in the case group (1.9±0.9 vs 1.1±0.8; P=0.03).

CONCLUSIONS: The Achromobacter spp. status in CF shows a trend towards more severe airflow obstruction and an association with accelerated decline in lung function parameters.