The unusual approach of removing antibodies from the blood stream can reduce the effects of chronic infections, according to a study published in the American Journal of Respiratory and Critical Care Medicine.

In the study, two patients with bronchiectasis who suffered from chronic Pseudomonas aeruginosa infections that were resistant to many antibiotics; a 64-year-old male, diagnosed with bronchiectasis aged fifteen, and a 69-year-old female who had bronchiectasis from childhood.

Bronchiectasis is a disease that leads to permanent enlargement of the airways in the lung. 

Chronic Pseudomonas aeruginosa lung infections commonly occur in patients suffering from bronchiectasis.

Pseudomonas aeruginosa is a common bacterium that can cause the disease and is known as a multi-drug resistant pathogen, recognised for its advanced antibiotic resistance mechanisms and association with serious illnesses.

The patients volunteered to be part of an explorative treatment that built on previous findings from the research group in 2014.

"These patients had an excess of a particular antibody in the bloodstream. In contrast to the protective effect normally associated with the antibody, in these patients the antibody stopped the immune system killing the Pseudomonas aeruginosa bacterium and this worsened the patients' lung disease," Ian Henderson, Director of the Institute of Microbiology and Infection at the University of Birmingham said explaining the study.

"We decided to remove this antibody from the bloodstream and the outcomes were wholly positive," he said. 

"We needed a brand new way of tackling this problem. Working with kidney and immunology experts, we used a process known as plasmapheresis that is somewhat like kidney dialysis," said Tony De Soyza, Bronchiectasis service lead, Newcastle Upon Tyne Hospitals Trust.

"The plasmapheresis involved the removal, treatment, and return of blood plasma from circulation, and was done five times in a week in order to remove antibody from the patients. We then replaced antibodies with those from blood donations. This treatment restored the ability for the patients' blood to kill their infecting Pseudomonas," he said. 

Both patients reported a rapid improvement in health and well being, greater independence and improved mobility compared to any point in the previous two years.

"This shows that we can improve patient well being significantly, by reducing the need for treatment and the numbers of days spent in hospital, which will also help to reduce the reliance on antibiotics. The next step is to do longer term studies to investigate whether an earlier intervention, with slightly less aggressive therapies, could help prevent disease progression in patients," Henderson added.