Analysis of the turin umbilical cord blood bank registry

BACKGROUND: The polymorphic nature of the HLA system reduces a patient's pr obability of finding an HLA-compatible unrelated bone marrow (BM) donor, ev en though more than 6 million individuals are enrolled in international reg istries. Recently, umbilical cord blood (UCB) has been successfully employe d as a source of HPCs. The use of such cells reduces the risk of GVHD and a llows transplants with one or two HLA mismatches. UCB represents an expensi ve resource: therefore, it is necessary to carefully manage the UCB unit in ventory. STUDY DESIGN AND METHODS: The current study analyzed the genetic heterogene ity of HLA-A, -B, and - DR gene frequencies between pools of UCB and unrela ted-donor BM in the Piedmont (an administrative region of Italy). An Italia n hematology patient's probability of finding complete or partial matches a s a function of donor pool size was determined by considering subsamples ra ndomly selected from the local unrelated BM donors. RESULTS: The HLA gene frequencies in UCB and unrelated-donor BM pools were not significantly different. The search simulation, based on actual HLA phe notypes, showed that the percentage of Italian patients matched with an HPC unit increases remarkably if 1 or 2 mismatches are accepted, reaching a pr oportion of 90 percent with an inventory of only about 500 units, while the increment is not so remarkable if the number of UCB units is greater. CONCLUSION: To optimize economic resources and to be internationally compet itive, UCB banks should aim to increase the genetic heterogeneity of their units rather than increasing the UCB inventory, acquire efficient quality c ontrol systems, and acquire and preserve UCB units with a greater number of nucleated cells.