Role of alveolar macrophage proteinase genetic polymorphisms in the development of emphysema

Emphysema is a destructive lung disease that obstructs the airways and compromises oxygen transfer from the lungs to the bloodstream, causing a decrease in respiratory function. More than 1,100 people die of the disease in Canada each year. Currently, there are no treatments to cure emphysema. Cigarette smoking is the major risk factor for developing the disease. Yet only 15 to 20 per cent of smokers develop symptoms. An increase in protein-degrading enzymes called proteinases is believed to play a role in the origin of emphysema. Previous studies also suggest a genetic predisposition to airflow obstruction. Variations in the genes regulating these proteinase enzymes may be responsible for individual differences in response to cigarette smoke. Alison Wallace is researching whether genetic variants in proteinases increase smokers’ susceptibility to emphysema. If so, this information would help identify people at risk for the disease, contributing to early promotion of anti-smoking strategies and possibly leading to new methods for early detection and treatment. In addition, drugs that inhibit proteinases could be targeted to patients predisposed to emphysema, but unable to quit smoking.