Background: Stenotrophomonas maltophilia is one of the most common multidrug-resistant organisms isolated from the cystic fibrosis (CF) respiratory tract but it is unknown how it influences the long term clinical outcomes of CF patients.
Objective/Hypothesis: To characterize the immune response to S. maltophilia and its association with clinical outcomes in CF patients over time.
Methods: This was a longitudinal study from 2007-2014 of CF patients followed at The Hospital for Sick Children and St. Michael’s Hospital. All patients were classified as: 1) those with chronic S. maltophilia: ³2 positive cultures/year, 2) intermittent S. maltophilia: 1 positive sputum culture/year, and 3) no S. maltophilia cultures/year with and without chronic P. aeruginosa. IgG/IgA/IgM serologic responses were measured in serial sera samples by ELISA using whole cell S. maltophilia antigen. Results were calculated as the ratio of the average serum sample optical density to the average optical density of the negative control wells. Antibody levels for each patient were compared longitudinally to their rate of decline in FEV1 % predicted, body mass index, and rate of hospitalization.
Results: S. maltophilia antibody levels were measured in 350 sera samples from 113 CF patients. Median baseline antibody levels were 1.56 (range 0.996-5.15) in chronic patients, 1.09 (range 0.907-3.79) in intermittent patients, and 1.12 (range 0.737-4.86) in patients with no S. maltophilia.
Conclusions:
Preliminary data suggests antibody levels to be significantly higher in patients with chronic S. maltophilia, and no significant difference between intermittent S. maltophilia and no S. maltophilia.
Differential Persistence among Genomovars of the Burkholderia cepacia Complex in a Murine Model of Pulmonary Infection
