Stem cell transplantation in primary immunodeficiencies

To review indications and outcomes of haematopoietic stem cell transplantation in primary immunodeficiencies, in light of recent advances in the field.

Remarkable improvements in the outcome of haematopoietic stem cell transplantation in primary immunodeficiencies have recently been reported. This is a result of the successful use of alternative donors and more effective strategies to prevent and treat complications. These advances have now permitted the indications for haematopoietic stem cell transplantation to be extended in primary immunodeficiencies.

The optimal results of haematopoietic stem cell transplantation in primary immunodeficiencies have long been obtained with related human leukocyte antigen-identical donors, an option limited to a minority of patients. Transplantation from mismatched related donors has been used with good results mainly in infants with severe combined immune deficiency, but has been associated with significantly delayed or incomplete immune reconstitution. Recent data indicate that transplantation from matched unrelated donors and cord blood transplantation represent valid alternatives, which can be used in all forms of severe primary immunodeficiencies. This, along with careful monitoring of infections, coupled with preemptive treatment, has resulted in a significant improvement in the outcome of haematopoietic stem cell transplantation for severe forms of primary immunodeficiencies.