In April 2017 Duke University released the results of a study looking at stem cells to help people with Autism. They looked at the effects of cord blood on 25 children with autism. The results of that study were impressive but it was a safety study only, so additional testing was started. Duke recently published some results from the next study in the series.
It does seem that stem cells can help in some symptoms of Autism, which is initially helping those with cord blood from a family member. I wonder if autologous transplants (taking your own stem cells found in bone and other organs) will be something to experiment with in the future?
It should also be noted that while stem cells seem to resolve some issues, it may not be the way for every person or the only way.
June 2007 Stem Cell Therapy for Autism