Addressing CFTR dysfunction improves overall bacterial clearance from sputum, according to research presented here at ECSF 2015.

The study looked at the short and long term effects of ivacaftor on the sputum microbiota of 12 adult patients with at least one copy of the G551D CFTR mutation, eight of whom were culture positive for P. aeruginosa (P.a).

Presenting the findings to delegates lead author Lucas Hoffman from Seattle, US,  said treatment with the CFTR modulator resulted in a rapid and substantial decline in P.a absolute and relative abundance within the first week which levelled off and then continued to decrease over the next two years.

The microbiological changes appeared to correlate with spirometric improvement at day 7, he told delegates.

There was also an increase in bacterial diversity but that was only significant at later time points, he said.

While stressing that the study was small, Hoffman said the results implied that addressing CFTR function improves overall bacteria clearance from the sputum.

“There appears to be a particularly strong effect on P. aeruginosa which we think is very interesting, but while we have no shortage of hypothesis, we don’t yet know why it’s the case,” he said.

“Decreasing the airway burden of many types of bacteria may be possible with CFTR targeted treatment,” he added.