IN-UTHRO TRANSPLANTATION OF FETAL LIVER HAEMOPOIETIC STEM CELLS IN MONKEYS

To evaluate the potential of in-utero transplantation of fetal haemopoietic stem cells (HSCs) for permanent engraftment as a treatment of congenital haemoglobinopathies, fetal rhesus monkeys were transplanted with HSCs derived from fetal livers. Five pregnant monkeys (60-62 days' gestation) were given an in-utero intraperitoneal injection of fetal liver cells (108-109 cells/kg estimated fetal recipient body weight) derived from opposite sex donors at 59-68 days' gestation. Engraftment was confirmed by karyotype analysis of peripheral blood leucocytes and bone marrow; cells of donor sex were found among the recipient cells. Donor cell engraftment was apparent in four of five in-utero HSC transplant recipients at birth. Engraftment involved lymphoid (2·9-8·0% donor cells), erythroid (5·3-12·5%), and myeloid (8·5-15·4%) lineages and has persisted for up to 2 years without evidence of graft-versus-host disease.