Stem cells transplanted to female foetus

A Swedish case where a certain type of stem cells has been transplanted to a foetus with a serious disease, was made public today. The results suggest that fetal mesenchymal stem cells may be a valuable source for transplantation and cell therapies.

A female foetus with multiple intrauterine fractures, diagnosed as severe osteogenesis imperfecta, was transplanted with HLA-mismatched mesenchymal stem cells (MSCs) in the 32nd week of gestation. At 35 weeks, the baby girl was delivered by caesarean section. At nine months of age patient lymphocyte proliferation against donor MSCs was not observed in co-culture, indicating that the patient was not immunised against the allogeneic cells.

During the first two years of life three fractures were noted and growth followed the same curve. Thus, allogeneic mis-matched MSCs can be safely transplanted in utero to a patient with severe OI, where the cells engraft in bone. MSCs are present in various tissues of fetal and adult origin. Fetal MSCs differentiated into osteogenic, chondrogenic and adipogenic lineages when induced in vitro, which means that they have the capability to mature into bone, cartilage and fat tissue.

This study is part of a doctoral dissertation defended by Cecilia Götherström at Karolinska Institutet, Sweden, today, Friday December 17, 2004. In the thesis is presented detailed studies on fetal and adult MSCs.

The results suggest that fetal MSCs are immunologically privileged cells and have potentials for allogeneic transplantation.

To conclude, fetal MSCs may be a valuable source for transplantation and cellular therapies.