A dysfunctional immune system and the likelihood of losing your sense of smell

Our sense of smell may be more important than we think. Tests on mice suggest that our sense of smell may signal how well our immune system is functioning. The relationship between the immune system and the olfactory system Evidence linking the immune system and the olfactory system has been accumulating for some time. For example, women seem to prefer the scent of men with immune system genes different from their own. Other studies suggest that the health of our immune system may influence how extroverted we are. Mouse Testing – Introduction To explore this topic further, Fulvio D'Acquisto and his colleagues at Queen Mary University of London tested mice lacking the RAG (recombinant activating gene) gene, which controls the development of immune cells. The absence of this gene in mice results in a less efficient immune system. Some genes are expressed differently, including genes involved in the olfactory system. Testing process D'Acquisto's team measured how long it took mice to find chocolate cookies hidden in their cages. Mice lacking the RAG gene took five times longer than normal mice. Furthermore, they failed to respond to the smell of almond or banana (mice typically find these scents highly enticing), although they still responded to the smell of other rodents. Deeper analysis revealed abnormalities in their nasal epithelium—physical evidence that their sense of smell may be impaired. Mouse tests – conclusion D'Acquisto sees this as confirmation of the fact that people with compromised immune systems often lose their sense of smell. Systemic lupus erythematosus—an autoimmune disease in which the immune system mistakenly attacks tissues in the skin, joints, kidneys, brain, and other organs—is one such example. This observation adds to the research on the connection between olfaction and other body systems, including the immune system. However, immunologist Daniel Davis notes that it will be difficult to prove how these laboratory measurements of olfaction will affect real-world behavior in wild animals. Test results and reality D'Acquisto suspects that different types of immune compromise may have different consequences for the sense of smell and behavior. He argues that someday it may be possible to diagnose certain diseases based on these changes in the ability to smell.