Have you been following his story?
"Stem cell infusion has just started. Please pray that they get into Matthew's system and do their job. Dr. Frangoul warned us again that the white blood cells will immediately go to any inflammation and/or infection in his body to start fighting. If it in his lungs, it could cause a major problem. Jeff is kind of freaking out over this, even though we've discussed it several times. He tends to forget things or maybe he just ignores things he doesn't really want to hear."