This study aimed to investigate the clinical effect of
transplantation of CD133⁺ peripheral blood stem cells or umbilical cord mesenchymal stem cells via the hepatic artery in children with type II
hyperammonemia and its possible action mechanism. Umbilical cord mesenchymal stem cells were obtained by collecting cord blood (100-150 mL) from healthy fetuses and separating stem cell
suspension (5 mL) from the cord blood by hydroxyethyl
starch sedimentation. CD133⁺ peripheral blood stem cells were obtained by mobilizing peripheral blood from the fathers of sick children using recombinant human
granulocyte colony-stimulating factor for 5 days, collecting mononuclear cells (120 mL), and separating out CD133⁺ cells by sorting. With catheterization and percutaneous
puncture, the obtained stem cells were slowly injected into the liver of sick children via the hepatic artery. The changes in clinical symptoms and laboratory indices such as blood
ammonia, liver function, and
arginine and
citrulline concentrations were observed. After
stem cell transplantation via the hepatic artery, the 6 children showed significantly decreased blood
ammonia levels, and their blood
ammonia levels slowly increased 1 to 2 weeks later, but remained below 100 μmol/L, and changes in
glutamic-pyruvic transaminase levels were similar to blood
ammonia. Plasma
citrulline and
arginine concentrations increased significantly after
transplantation and the increase in
citrulline level exceeded the increase in
arginine level. An 8 months follow-up visit for one typical patient showed that the weight and height increased after
transplantation and sleep was improved without night crying. The child could actively gaze at interesting objects instead of responding indifferently and started to say simple words. With regard to fine motor skills, the child could pinch things with the thumb and middle finger instead of displaying a lack of hand-eye coordination and progress was also made in gross motor skills. Gesell test showed that the child made progress for an average of 3.82 months in all areas. It was concluded that after
stem cell transplantation, children with type II
hyperammonemia have decreased blood
ammonia levels, stable and improved liver function and steadily increased plasma
citrulline and
arginine concentrations. They display a progressive trend in such aspects as movement, language and environmental adaptability. It is hypothesized that
stem cell transplantation via the hepatic artery partially or totally activates, or provides supplementary
ornithine carbamoyl transferase, so that plasma
citrulline and
arginine concentrations increase and
urea cycle disorder can be corrected to some extent.