A new Harvard T.H. Chan School of Public Health co-authored study provides further evidence linking both arsenic poisoning and the chronic respiratory disease cystic fibrosis (CF) to damage in the CFTR protein. An examination of arsenic-exposed patients in Bangladesh found that they had elevated sweat chloride levels — the typical diagnostic sign of CF. While many patients also showed respiratory symptoms consistent with a CF diagnosis, none actually had the disease.
The study appeared online February 5, 2015 in the New England Journal of Medicine.
CF is caused by a genetic defect in the CFTR protein, which regulates the flow of chloride in and out of cells. Recent studies in cell culture show that arsenic causes the CFTR protein to break down. Better understanding of how arsenic damages the CFTR protein could lead to new, more affordable drugs for CF, according to the authors. The study also suggests that patients exposed to arsenic should be monitored for CF-like disease.
Co-authors include Maitreyi Mazumdar, assistant professor in the Department of Environmental Health and David Christiani, Elkan Blout Professor of Environmental Genetics. The study was supported by the Harvard University Center for the Environment and the Harvard–National Institute of Environmental Health Sciences (NIEHS) Center.
Elevated sweat chloride levels due to arsenic toxicity (New England Journal of Medicine)