Analysis of the Spanish CCR5 -∆32 inventory of cord blood units: lower cell counts in homozygous donors

The possibility to use CCR5 -∆32 umbilical cord blood to cure HIV infection in patients in need of a hematopoietic transplant has been suggested. The less stringent HLA compatibility needed in this type of transplant facilitates the search of a suitable donor having the CCR5 -∆32 mutation. To achieve an inventory of CCR5 -∆32 cord blood units, the 20,236 best cell quality units of the Spanish Registry were genotyped. Furthermore, their CD34 + and total nucleated cells counts, blood type, gender, HLA and donor’s geographical and ancestral origin were analyzed. The results showed 130 (0.64%) units homozygous for the deletion, 2,646 (13.08%) heterozygous and 17,460 (86.28%) did not present the mutation. Interestingly, a significant lower amount of CD34 + cells was found in the CCR5 -∆32 homozygous units. In addition, a significant association was found among donor’s ancestral origin and the mutation, with a higher percentage of CCR5-∆32 units with a European ancestry. In summary, identification of a relatively high number of CCR5 -∆32 units is feasible and will facilitate the development of clinical trials for HIV cure in patients requiring hematopoietic transplantation. Further studies are required to understand the significance of lower cell counts within the CCR5 -∆32 homozygous group and its clinical impact.