Comparing the harmful effects of nontuberculous mycobacteria and Gram negative bacteria on lung function in patients with cystic fibrosis.
To better understand the relative effects of infection with nontuberculous mycobacteria and Gram negative bacteria on lung function decline in cystic fibrosis, we assessed the impact of each infection in a Danish setting.



Longitudinal registry study of 432 patients with cystic fibrosis contributing 53,771 lung function measures between 1974 and 2014. We used a mixed effects model with longitudinally structured correlation, while adjusting for clinically important covariates.



Infections with a significant impact on rate of decline in %FEV1 were Mycobacterium abscessus complex with -2.22% points per year (95% CI -3.21 to -1.23), Burkholderia cepacia complex -1.95% (95% CI -2.51 to -1.39), Achromobacterxylosoxidans -1.55% (95% CI -2.21 to -0.90), and Pseudomonas aeruginosa -0.95% (95% CI -1.24 to -0.66). Clearing M. abscessus complex was associated with a change to a slower decline, similar in magnitude to the pre-infection slope.



In a national population we have demonstrated the impact on lung function of each chronic CF pathogen. M. abscessus complex was associated with the worst impact on lung function. Eradication of M. abscessus complex may significantly improve lung function.
Copenhagen Cystic Fibrosis Center, Department of Infectious Diseases, Rigshospitalet, Copenhagen University, Denmark. Electronic address: tavs.qvist@gmail.com.
Tavs
T
Qvist
Department of Public Health and Policy, University of Liverpool, Liverpool, UK. Electronic address: david.taylor-robinson@liverpool.ac.uk.
David
D
Taylor-Robinson
Department of Medical Informatics, Biometry and Epidemiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany. Electronic address: elisabeth.waldmann@fau.de.
Elisabeth
E
Waldmann
Aarhus Cystic Fibrosis Center, Department of Pediatrics, University Hospital Skejby, Aarhus, Denmark. Electronic address: hvo@dadlnet.dk.
Hanne Vebert
HV
Olesen
Copenhagen Cystic Fibrosis Center, Department of Pediatrics, Rigshospitalet, Copenhagen University, Denmark. Electronic address: christunte@dadlnet.dk.
Christine Rønne
CR
Hansen
Copenhagen Cystic Fibrosis Center, Department of Infectious Diseases, Rigshospitalet, Copenhagen University, Denmark. Electronic address: ihm@dadlnet.dk.
Inger Hee
IH
Mathiesen
Copenhagen Cystic Fibrosis Center, Department of Clinical Microbiology, Rigshospitalet, Copenhagen University, Denmark. Electronic address: hoibyniels@gmail.com.
Niels
N
Høiby
Copenhagen Cystic Fibrosis Center, Department of Infectious Diseases, Rigshospitalet, Copenhagen University, Denmark. Electronic address: terese.katzenstein@regionh.dk.
Terese L
TL
Katzenstein
Institute of Child Health, University College London, London, UK. Electronic address: rosalind.smyth@ucl.ac.uk.
Rosalind L
RL
Smyth
Faculty of Medicine, Lancaster University, Lancaster, UK. Electronic address: p.diggle@lancaster.ac.uk.
Peter J
PJ
Diggle
Copenhagen Cystic Fibrosis Center, Department of Infectious Diseases, Rigshospitalet, Copenhagen University, Denmark. Electronic address: tania.pressler@gmail.com.
Tania
T
Pressler
D000328:Adult; D002908:Chronic Disease; D003550:Cystic Fibrosis / Q000175:diagnosis / Q000453:epidemiology / Q000382:microbiology / Q000503:physiopathology; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006090:Gram-Negative Bacteria / Q000302:isolation & purification / Q000472:pathogenicity; D016905:Gram-Negative Bacterial Infections / Q000175:diagnosis / Q000503:physiopathology; D006801:Humans; D008137:Longitudinal Studies; D008168:Lung / Q000382:microbiology / Q000503:physiopathology; D008297:Male; D009165:Mycobacterium Infections, Nontuberculous / Q000175:diagnosis / Q000503:physiopathology; D009170:Nontuberculous Mycobacteria / Q000302:isolation & purification / Q000472:pathogenicity; D012129:Respiratory Function Tests / Q000379:methods / Q000706:statistics & numerical data
Abscessus; CF; Gram negative; Lung function; NTM