By Patrick Yang ’20
Bronchiectasis occurs when the lung’s bronchial tubes are permanently damaged or inflamed, leading to chest pain, coughing up blood, and large production of mucus. These damaged lung walls also make bronchiectasis patients more prone to chronic infection and, specifically, Pseudomonas aeruginosa lung infections, which increase mortality rates. However, previous research has shown that patients with bronchiectasis and chronic P. aeruginosa infection exhibit high levels of IgG2 antibody, an inhibitory antibody that surprisingly stops the immune system from killing the bacteria. IgG2 nonlethally binds to the bacteria, preventing the binding of other antibodies that would otherwise kill them. Since patients with severe bronchiectasis are typically beyond the point of lung transplantation, an alternative therapy is needed to treat infection. In a recent study, Dr. Timothy J. Wells and associate researchers at the University of Birmingham demonstrated a new and revolutionary method that destroys the bothersome antibodies in a P. aeruginosa infection.
Dr. Wells’s team observed a 64-year-old male and 69-year-old female who were diagnosed with severe bronchiectasis and chronic P. aeruginosa infection. The two were both housebound, required long-term oxygen ventilatory support, and were unresponsive to treatment and antibiotics. In order to improve their conditions, the researchers employed a new method of treating lung infection called plasmapheresis that cycles and renews the patient’s plasma through a machine – a process similar to kidney dialysis. Plasmapheresis was conducted for four hours daily for five days and, most importantly, removed IgG2 antibodies and pathogens. After two weeks post-treatment, both patients were no longer housebound, days spent in the hospital and antibiotic use dropped significantly, and inflammation decreased. One patient’s expiratory volume also increased significantly from 27.9% to 37.8% after treatment. However, IgG2 levels increased after 90 days post-plasmapheresis and reemergence of symptoms and P. aeruginosa in mucus occurred, suggesting that periodic plasmapheresis treatment is necessary.
As a brand new method of treating lung infection, plasmapheresis has impressively shown its ability to remove infectious bacteria and improve living conditions. Since this experiment used plasmapheresis as a salvage therapy, or last resort, future analysis of the therapy will need proper controls and larger sample sizes to have more conclusive results. Nevertheless, plasmapheresis may eventually become the norm in future patients.
- T.J. Wells, et al., The use of plasmapheresis in patients with bronchiectasis with Pseudomonas aeruginosa infection and inhibitory antibodies. American Journal of Respiratory and Critical Care Medicine 195, (2017). doi: 10.1164/rccm.201603-0599LE.
- Image retrieved from: https://commons.wikimedia.org/wiki/File:Bronchiectasis.png