ABSTRACT
HLA molecules play a key role in transplant medicine and disease pathogenesis, being a useful tool in predicting disease progression and identifying potential solid organ donors (SOD). The Coronavirus disease 2019 (SARS-CoV-2) pandemic had a huge worldwide impact, which strongly affected the activity of different transplant programs. So far, it has been shown that HLA type may be a crucial differentiator between individuals who have varying occurrence, morbidity, and mortality response to SARS-CoV-2. In this work, we investigated if differences in the frequency of SOD HLA alleles, were impacted during SARS-CoV-2 pandemic. We performed a retrospective file audit of all HLA-typings done in 2 subsets of SOD pre-pandemic period (ppp) (n = 379) and pandemic period (pp) (n = 351), collected in equivalent timeframes. We discuss data for the major HLA-A, HLA-B, HLA-C, and HLA-DRB1 allele groups at serological phenotyping level. Overall, there was a 7% SOD decrease in the pp. Considering both periods, the most common allele groups were HLA-A2, HLA-B35, HLA-Cw7, HLA-DR7 and HLA-DQ2. For the ppp group, the most common alleles were HLA-A2, HLA-B35, HLA-Cw7, HLADR13 and HLA-DQ2, while in the pp group the most common alleles were HLA-A2, HLA-B44, HLA-Cw7, HLA-DR4 and HLA-DQ2. When comparing both populations at the serological phenotyping level an increased in relative frequency was found for 10, 12, 8, 8 and 2, and a decreased was found for 10, 24, 8, 6 and 5 for HLA-A, -B, -C, -DR and -DQ, respectively. The significant variation within the HLA frequencies between the different pre-pandemic and pandemic groups highlights the value of population-specific HLA-typing. Furthermore, the identification of different frequencies among both populations will impact in patients HLA compatibility with SOD thus impacting their transplantability.