CRITICAL ROLE DISCOVERED FOR INNATE
IMMUNITY IN LUNG TRANSPLANT REJECTION
Researcher investigators have identified a critical role that innate immunity plays in lung transplant rejection which they believe has important implications for patients. (Innate immunity is the process that performs a major role in host defense during the early stages of infection because it involves the recognition of invading pathogens or "foreign" substances.) The medical scientists analyzed deoxyribonucleic acid (DNA) from 174 lung transplant recipients and 157 of their cadaver donors. The study authors point out that cardiac/pulmonary surgery, without or without cardiopulmonary bypass, has been shown to increase circulating endotoxin levels. (Endotoxins are heat stable toxins associated with the outer membrane of certain gram negative bacteria.) Endotoxins serve as a prototypical trigger of innate immunity by interacting with toll-like receptor 4 (TLR4) to recruit and activate the cellular materials necessary for an appropriate adaptive response by the body. The researchers said their results suggest that activation of innate immunity in lung transplant recipients through TLR4 contributes to the development of acute rejection after lung transplantation. They believe therapies directed at the inhibition of innate immune responses mediated by TLR4 may represent a novel and effective means of preventing acute rejection after lung transplantation. The study appears in the second issue for September 2003 of the American Thoracic Society's peer-reviewed American Journal of Respiratory and Critical Care Medicine.
PRESCHOOL CHILDREN WITH ASTHMA
TESTED FOR PULMONARY FUNCTION
In one of the first pulmonary function studies to compare preschool children with asthma to healthy controls of similar age, French researchers, using tests that did not require active cooperation, compared the results of 74 children with asthma to those of 84 healthy young
Contact: Cathy Carlomagno
American Thoracic Society