Frequency of the CCR5Δ32 Variant in Haematopoietic Progenitor Cell Donors From Argentina: Implications for Transplantation in HIV-1 Infected Patients

The genetic variant CCR5Δ32 is mostly represented in European populations and has been studied for its protective effect against human immunodeficiency virus (HIV) infection. The Berlin patient and others have received a haematopoietic stem cell (HSC) transplant from CCR5Δ32/Δ32-HLA compatible donors and are considered cured for HIV. Several studies emphasize the need to seek donors with this condition in the HSC registries. The frequency of the CCR5Δ32 allele is unknown in Argentina. The aim of this study was to determine the frequency of the CCR5Δ32 allele and genotype in donors registered in the National Registry of HSC-INCUCAI-Argentina, and to evaluate possible implications in transplantation of HIV patients. A total of 238 874 blood samples were analyzed molecularly for CCR5Δ32/HLA. In the population, we report a frequency of 5.46% for CCR5Δ32 and 10.38% and 0.27% in the CCR5Δ32/WT and CCR5Δ32/Δ32, respectively. The genotypes registered some differences at the national level and depending on the donor's ancestry. In addition, a homogeneous distribution of HLA alleles was identified between carriers and non-carriers of CCR5Δ32. We report the allelic and genotypic frequencies of CCR5Δ32 in Argentina, and its distribution, considering search strategies for CCR5Δ32/Δ32 donors that provide a transplant alternative to patients infected with HIV.