Why We Get Colds

by David Bronstein •

Environment and Innate Immune Function Interplay

The new study from Dr. Bleier and his colleagues underscores the important role environmental factors can play in human host defenses.

“Dr. Bleier’s findings are fascinating because they link environment and climate together with disease, and it shows that there probably is [an association] between the two when it comes to innate immune function in the nose,” said Murray Ramanathan, Jr., MD, professor of otolaryngology–head and neck surgery and director of the Greater Washington area practices for Johns Hopkins Otolaryngology Head and Neck Surgery in Bethesda and Washington, D.C. “To me, that’s the really innovative part of his work.”

Dr. Ramanathan, who first started researching the innate immune function of the nose when he was a resident at Johns Hopkins in the early 2000s (Otolaryngol Head Neck Surg. 2007;136:348–356), said he has come to appreciate how chronic rhinosinusitis can be the result of dysregulated innate immune responses. But in the last 10 years, he noted, he has been looking at how the environment also might contribute to disease processes in the upper sinonasal airway (Am J Respir Cell Mol Biol. 2017;57:59–65). “Seeing Dr. Bleier correlate air temperature and innate immune function really resonates.”

Traditionally, Dr. Ramanathan acknowledged, many researchers questioned whether air quality could make much of a difference in chronic sinus disease. “The thought was that people just had a genetic predisposition to, say, nasal polyps,” he said. “Now there’s quite a bit of research demonstrating a strong association between rhinologic diseases, air pollution, and other airborne insults [Laryngoscope. 2022;132:2103–2110]. It’s time to pay more attention to these exogenous factors, and Dr. Bleier’s work is a good reminder of that.”

Dr. Patel agreed. “I find [Dr. Bleier’s findings] fascinating and telling as far as the implications regarding our evolution as human beings,” she said. “We know from both archeologic and DNA-based historical data that human beings first evolved in the warmer climates of the Earth and then spread from there. It’s therefore not surprising that a component of our immune system works best in warm climates.”