There are few children with new coronary pneumonia and mild symptoms. The latest analysis found:
Minor lung physiology and immune function may be different from adults
Science and Technology Daily, Washington, July 8 (Reporter Liu Haiying) In this new coronary pneumonia epidemic, the proportion of children, the proportion of serious illnesses, and the mortality rate are much lower than those of adults. What is the reason? Researchers at the University of Texas Health Science Center and Baylor College of Medicine in Houston said that this is likely caused by differences in lung physiology and immune function between children and adults.
They published a research paper in the recently published American Journal of Physiology: Pulmonary Cells and Molecular Physiology. Of the original 149,082 cases in the United States (as of April 2, 2020), only about 1.7% of patients were under 18 years of age Of the minors, there were only 3 death cases of neonatal pneumonia confirmed by the US Centers for Disease Control and Prevention at that time, and the U.S. population under the age of 18 accounted for 22% of its total population. The researchers believe that the rate of children with symptomatic infections, hospitalizations and deaths is so low that more analytical studies are needed, and perhaps key information for the treatment of new coronary pneumonia can be found.
The researchers pointed out that the data indicate that the number of children infected is small, and most children will only have mild symptoms after infection, while adults will develop acute lung injury and acute respiratory distress syndrome. They believe that the pathophysiological mechanism that causes less infection in children and less lung damage may be the reduction of the expression of the media necessary for the virus to enter the epithelial cells of the respiratory tract, and the immune system response of children is different from that of adults.
Specifically, one is that the number of angiotensin-converting enzyme 2 (ACE2, a key protein in the infection of lung cells by New Coronavirus) in children is less than that of adults, reducing their chance of being infected by the virus; second, the immune system of children The response to the virus is different from that of adults. After infection, the number of CD4+ T cells in the body will not be significantly reduced, and the production of pro-inflammatory and anti-inflammatory cytokines will not be significantly imbalanced, which makes them more powerful. Recovery ability, which greatly reduces the chance of developing serious illness.
The researchers pointed out that the analysis of the causes of differences between children and adults in the new coronary pneumonia epidemic will help scientists find key information for the treatment of new coronary pneumonia. The above findings may be used to guide treatment trials for adult patients.