When we looked at people’s lymph nodes, we were struck by how many of the nodes in the lung appeared black in color, while those in the GI tract and other areas of the body were the typical beige color
Elderly people are especially vulnerable to respiratory infections, a fact brought into stark relief by the Covid pandemic. The death rate from Covid is 80 times greater in people over age 75 than in younger adults, and the elderly are also more vulnerable to influenza and other infections of the lung.
The Columbia researchers weren’t initially looking at air pollution’s influence on the immune system. More than ten years ago, they began to collect tissues from deceased organ donors to study immune cells in multiple mucosal and lymphoid tissues. Such cells have been largely inaccessible to researchers studying the immune system where sampling is limited to peripheral blood. “When we looked at people’s lymph nodes, we were struck by how many of the nodes in the lung appeared black in color, while those in the GI tract and other areas of the body were the typical beige color,” says Donna Farber, PhD, the George H. Humphreys II Professor of Surgical Sciences (in Surgery) and professor of microbiology & immunology at Columbia University Vagelos College of Physicians and Surgeons, who led the study.
And as the researchers collected more tissue from younger donors, they also noticed an age difference in the appearance of the lung’s lymph nodes: Those from children and teenagers were largely beige while those from donors over age 30 looked were tinged with black and got darker with increasing age.
Source: Healthcare in Europe