Neurologists in the United States have discovered the reasons behind the low incidence of brain tumors in people with asthma.
According to a study published in the journal Nature Communications.
In 2015, neurologists published a study suggesting that some children who are genetically susceptible to developing tumors along the optic brain pathway do not develop asthma at the same rate that you would expect from the general population.
Some lab research found evidence that these children's tumors were the result of an interaction between the optic nerve and certain immune cells in the brain, known as T cells and glia.
As there is a connection between asthma and T cells, being an inflammatory disease, neurologists have begun to question whether these immune cells are the common link between the two conditions.
To confirm the validity of the findings, the researchers genetically modified experimental mice to be susceptible to optic nerve tumors, in addition to stimulating some of them to develop asthma, especially newborns.
The result was surprising, as mice with induced asthma showed no evidence of brain tumors, while mice without asthma showed signs of brain tumor.
Through the experiment on mice, which showed a clear difference in the behavior of T cells, the researchers concluded that something in asthma was harming the lungs while helping the brain.
Neurologist David Guttman, of the University of Washington, noted that T cells can be used to prevent brain tumors from forming and limiting their spread.
Through the previous experiment conducted on mice, the researchers found that preventing T cells in the mouse lung from producing a protein known as decorin, contributed to alleviating respiratory infections.
The current study also showed an increase in decorin formation in optic nerves, lymph nodes and spleen in mice with asthma.
This is what happens in humans with asthma, where the body's T cells appear, and decorin is formed, in a different proportion than what happens in mice.
The researchers concluded that the T-cell-derived protein may harm the lungs, while it could have positive effects in limiting the spread of brain tumors and preventing their formation.
Therefore, decorin may contribute to preventing the accumulation of cancer cells in humans.
"We are also studying the role of eczema and early childhood infections, because both involve T cells," Guttmann says. "As we better understand this connection between T cells and the cells that promote brain tumors, we will begin to find more opportunities to develop smart therapies to intervene in this process".