Microchimerism in the human brain: more questions than answers.

Recently, our group reported the presence of microchimerism (Mc) in the human brain by performing quantitative PCR on female human brain tissues to amplify male DNA. We found brain Mc to be relatively frequent in humans and widely distributed in this organ. Our data also suggested a lower prevalence of brain Mc in women without Alzheimer disease than women without neurological disease. Altogether, these findings suggest that Mc could sometimes influence health and disease of the brain. As further research will be required to clarify this issue, here we discuss some of the questions that could be addressed to improve our understanding.