What is the maximum degree of patient-donor incompatibility (mismatched HLA types) that can be tolerated in cord blood transplants?
Apparently quite large. Examples: Several clinical trials presented at the 43rd annual meeting of the American Society of Hematology in Dec. 2001 were transplanting adults with multiple (from 2 to 6) mis-matched cord blood units. Surprisingly, although these patients initially show a mix of HLA types (“chimerism”) from the different units, over time most survivors display a single dominant cord blood type. • Reference: Cord blood transplants: Making do with less by M.D. John Wingard Report on an adult patient in Britain who recovered after receiving a transplant of 7 cord blood units; one perfect match and 6 mis-matched • Reference: The Guardian newspaper 7/9/2002 Report on a study at the U. of Minnesota in which 23 patients were transplanted 2000-2003. Each received two partially matched cord blood units (now at 32 patients as of fall 2004). They have not figured out yet how to predict which cord blood unit will dominate in the end! • Reference: Barker JN, et al. Blood Oct2004; DOI 10
