Point-Counterpoint: Haploidentical Family Donors versus Cord Blood Transplantation

For patients who do not have a matched sibling donor or a volunteer matched unrelated donor, or when there is not enough time to line up a donor due to the rapid progression of the patient's disease, there are two rapidly available alternative stem cell donor sources: a haploidentical transplantation from a three-locus mismatched family member (parents, siblings, or children of the patients) [1Aversa F. Tabilio A. Velardi A. et al.Treatment of high-risk acute leukemia with T-cell-depleted stem cells from related donors with one fully mismatched HLA haplotype.N Engl J Med. 1998; 339: 1186-1193Crossref PubMed Scopus (1018) Google Scholar, 2Handgretinger R. Klingebiel T. Lang P. et al.Megadose transplantation of purified peripheral blood CD34(+) progenitor cells from HLA-mismatched parental donors in children.Bone Marrow Transplant. 2001; 27: 777-783Crossref PubMed Scopus (234) Google Scholar] or an unrelated cryopreserved umbilical cord blood (CB) from a CB bank [3Wagner J.E. Gluckman E. Umbilical cord blood transplantation: the first 20 years.Semin Hematol. 2010; 47: 3-12Abstract Full Text Full Text PDF PubMed Scopus (84) Google Scholar]. Until the advent of large unrelated donor panels, allogeneic stem cell transplants (SCT) using less than fully matched related donors were sporadically performed in situations where the risks of a mismatched transplant were matched by those of the underlying disease. With the availability of better than half-matched unrelated donors and the use of umbilical cord blood stem cell transplants (CBT) from 1990, the place of haploidentical-related SCT has become defined as an alternative to CBT when a fully matched donor is unavailable. The choice of CB versus haplo donor in this situation is worthy of debate. Practice around the world varies: for example, in the United States, CBT predominate. In contrast, curiously, in Europe, CBT were largely pioneered in countries speaking romance languages whereas teutonic language–speaking countries have been slow to adopt CBT. Here, we contrast the strengths and weaknesses of the two stem cell sources, as proposed by two experts in the field.