A genetic disease called SCID, short for severe combined immunodeficiency, forces patients to breathe filtered air and avoid human contact because their bodies’ natural defenses are too weak to fight germs. Although it affects fewer than 2,000 new births each year worldwide, SCID is a cousin to acquired immune deficiency syndrome triggered by a human immunodeficiency virus — HIV/AIDS.
Now, using a mouse model, Virginia Tech researchers in the September issue of The ISME Journal describe a potential biomarker to detect SCID by analyzing for a microbe in the fecal matter of infants.
“If SCID is not detected, children cannot live past their first year,” says Xin M. Luo, an assistant professor of immunology Virginia-Maryland College of Veterinary Medicine. “Now, we may have a noninvasive way to screen for this disease because this microbe may be present only in negligible amounts in healthy, young children. If larger populations of the microbe are present, quick examination is needed to prevent a potentially deadly emergency.”
Luo and his colleagues compared the gut microbes in healthy mice with those in mice with a defective immune system, both before and after weaning. They found that the defective mice had a greater supply of a particular microbe called Akkermansia muciniphila. When bone marrow transplants were performed on the defective mice to give them an adaptive immune system, the researchers found that this particular microbe returned to normal levels. The difference only occurs in younger mice and gradually subsides with age. “This is an interesting finding because it means we can potentially screen for this microbe at an early age to find defects in the immune system,” Luo adds. Read the study abstract.Read more