Cystic Fibrosis

Role

To provide ongoing research into the disease Cystic Fibrosis and other chronic suppurative lung diseases and hence improve quality of life.

Research

Other detailed research studies in subjects with Cystic Fibrosis (CF) have been conducted in the areas of Sleep Disordered Breathing and Microbiology. Recently Clinical Associate Professor Bye and Dr Catherine Dobbin have examined the effect of pulmonary exacerbations on sleep disordered breathing and neurocognitive function in patients with cystic fibrosis. The findings were that exacerbations of lung disease adversely affect sleep and tests of neurobehavioural performance in people with Cystic Fibrosis. These results have major implications for work, study and exam performance in people with CF.

Associate Professor Bye has recently played a major role in organising research collaboration with Canadian CF clinics, lead by Professor Shawn Aaron which has already resulted in a multicentre study examining combination antibiotic susceptibility testing to treat exacerbations of lung disease in CF associated with multiresistant bacteria. This study has been reported in Lancet. Further studies are in progress, including an Evaluation of a Decision Aid For Adult Cystic Fibrosis Patients Considering Referral for Lung Transplantation.

In the randomised, double blind, controlled clinical trial conducted in Canadian and Australian CF centres it was shown that antibiotic therapy directed by combination antibiotic susceptibility testing did not result in better clinical and bacteriologic outcomes compared with testing directed by standard culture and sensitivity techniques. (Lancet 2005)

A recent in vitro study by Hill et al conducted at our centre provided some possible insights into the above result. It was shown that multiresistant isolates of Ps aeruginosa derived from CF patients grown in anaerobic and biofilm conditions were significantly less susceptible to single and combination antibiotics than corresponding planktonic-grown isolates. Furthermore, the antibiotic combinations that were bactericidal under anaerobic conditions were often different from those that were bactericidal against the same organisms grown as biofilms. These findings illustrate the complexity of choosing appropriate combination therapy for multi-resistant Ps aeruginosa in the CF lung.

As part of a major collaboration with the Department of Infectious Diseases at University of Sydney a clonal strain of Ps. Aeruginosa has been described in a number of paediatric and adult cystic fibrosis clinics along the East coast of Australia. It appears that
there is patient-to-patient spread of bacteria. Cross sectional and longitudinal studies to determine the clinical significance of this strain are currently being undertaken.

Our group has also shown that the survival of patients with panresistant organisms following transplant is similar to that of patients with sensitive organisms. This information has important implications in the selection of patients for lung transplantation.