CSF donor–host microchimerism
In five patients (001, 007, 011, 012 and 013), it was possible to extract from CSF samples collected 3 months after treatment an adequate amount of genomic DNA to perform microchimerism analysis (median, 5.9 ng; range, 0.1–7.2). Upon optimization of a droplet digital PCR (ddPCR)-based method to ensure high sensitivity and accuracy, in one of these patients (012) the presence of donor-derived cells, amounting to 0.68% of the analyzed material, was detected (Extended Data Fig. 