- Availability of a 5/6 or 6/6 HLA A, B, and DR identical relative who is willing and able to donate allogeneic stem cells. Serological, low resolution or mid resolution molecular typing will determine the degree of match for HLA (Human Leukocyte Antigen) class I regardless of high resolution DNA typing results. High resolution typing will be used to determine the degree of match for HLA-DR.