[Transplantation of umbilical cord blood hematopoietic progenitor cells in children].

Aim: Retrospective study of the outcome of cord blood transplantation (CBT) in children in Spain.

Methods: Twenty-eight patients (mean age 6.5 years; mean weight 25 kg) received a CBT between July 1994 and May 1998 in several centres of the Spanish Pediatric Bone Marrow Transplant Group. In 2 patients the donor was an identical human leukocyte antigen (HLA)-sibling and in two the donor was a mismatched family donor. In 24 patients the donor was unrelated, and 21 of these received an HLA-mismatched CBT. Twenty-one patients (75 %) received a CBT for leukemia mainly in advanced phase. Seven patients were transplanted for genetic disease. Of these, five had congenital immunodeficiency. The conditioning treatment included total body irradiation in ten patients and combined chemotherapy in the remaining patients. In all patients graft-versus-host disease (GVHD) prophylaxis was performed with cyclosporine, and corticosteroids or methotrexate were added in patients with HLA-mismatched donors. The mean number of nucleated cells infused was 53.4 x 106/kg.

Results: Graft failure was observed in nine patients. Eighteen patients (64.3%) developed grade IIIV acute GVHD. Eight patients (28.6%) developed severe GVHD. Actuarial event free survival (EFS) of all the patients was 34.4 +/- 9% at 3 years, with a mean followup of 16.6 months. EFS was more favorable in patients with genetic disease (71>=6 17%) and in those with an HLA (A, B and DR) identical donor (6/6) (66>=6 19%).

Conclusions: The most favorable results were obtained in patients with genetic diseases. We observed an inverse correlation between EFS and patients with HLA identical donors. The high incidence of severe acute GVHD could have been related to a lack of accuracy in the HLA typography of some patients.