Chitin is a polysaccharide that is a major component of arthropod cuticle. Chitin is ubiquitous and the second most abundant polysaccharide on our planet next to cellulose. Molted exoskeletons, dead insects and mites can litter our environment with chitin dust. The dust can become airborne and invade our lungs, causing irritation and inflammation. To manage the chitin contamination, cells in our lungs secrete Acidic Mammalian Chitinase (AMC), an enzyme that breaks the polysaccharide into its simple sugar building blocks. The simple sugars can be absorbed by cells, further converted and integrated into body tissues or eliminated as waste. People with inadequate levels of AMC can suffer asthma and other lung disease.
Steven J. Van Dyken, Hong-Erh Liang, Ram P. Naikawadi, Prescott G. Woodruff, Paul J. Wolters, David J. Erle, Richard M. Locksley. Spontaneous Chitin Accumulation in Airways and Age-Related Fibrotic Lung Disease. Cell. Volume 169, Issue 3, 20 April 2017, Pages 497–509.e13