Helminthic therapy and chronic obstructive pulmonary disease (COPD)
COPD is a group of diseases that cause airflow blockage and breathing-related problems, including emphysema and chronic bronchitis.
Gleanings from the science
Autoimmunity plays a key role in the development of COPD [1] and, since helminths are known to be powerful modulators of the human immune system, effectively attenuating inflammation and reversing autoimmunity, they may potentially offer both prophylaxis and treatment for COPD. [2]
As well as the impact of the molecules secreted/excreted by worms, some helminth species - for example hookworms - also have a direct local effect on the lungs when passing through them during their initial migration from the skin to the intestines. This may have additional beneficial effects on the lungs, including a reduction in the host’s susceptibility to respiratory pathogens. 
Adverse changes to lung tissue that had occurred prior to commencing helminthic therapy are unlikely to be amenable to this intervention, but it may prevent the development of further damage by limiting inflammation.
It is possible that helminthic therapy may temporarily worsen COPD symptoms initially, as is often the case when this treatment is first introduced. This was seen experimentally when mice were infected with the human hookworm-like helminth, Nippostrongylus brasiliensis, which briefly initiated the onset of emphysematous pathology. However, this adverse change was quickly reversed by helminth-induced regulatory mechanisms that promote tissue repair and mitigate emphysema [4] and this would likely also be the case when hosting the human hookworm, Necator americanus (NA).