ABSTRACT Introduction: The Band 3 is a red blood cell protein that carries the Dia and Dib antigens from the Diego blood system. The SLC4A1 gene encodes Band 3; Band 3 Memphis is a polymorphism of normal Band 3 and has two variants, but only the variant II carries the Dia antigen. Objectives: Describe the frequencies of the DI*A and DI*B alleles and the Band 3 Memphis among blood donors, sickle cell disease (SCD) patients and Amazonian Indians. Methods: A total of 427 blood samples were collected and separated into three groups: 206 unrelated blood donors, 90 patients with SCD and 131 Amazonian Indians. We performed DI*A/B, normal Band 3 and Band 3 Memphis genotyping, using the Polymerase Chain Reaction Restriction Fragment Length Polymorphism (PCR–RFLP). Results: The frequency of the DI*A/DI*A genotype was 0.5% in blood donors and it was not found in other groups. The frequency of the DI*A/DI*B was higher in Amazonian Indians (33.6%) and the frequency of the DI*B/DI*B was highest in blood donors (92.2%). All 105 individuals tested were positive for the presence of normal Band 3 and of these individuals, only 5/105 (4.8%) presented the Band 3 Memphis mutation. Conclusion: We observed a higher frequency of the DI*B allele in blood donors and a low frequency of the DI*A/DI*A genotype in all groups studied. The Band 3 Memphis was found in a higher frequency in the blood donor group. Our findings highlight the importance of analyzing different population groups to gain a better understanding of the genetic association of blood group antigens.

Abstract Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was the responsible for the coronavirus disease 2019 (COVID-19) pandemic. Because of its high transmissibility, allied to the emergence of some variants of concern (VOC), like Alpha, Beta, Gamma, Delta, and Omicron, the detection of these strains must be rapid and efficient. Among the tests available, the reverse-transcriptase polymerase-chain reaction (RT-PCR) is considered the gold standard test for COVID-19 detection, and the use of specific primers and probes can discriminate the different COVID-19 variants. In this study, we screened 317 individuals tested positive for COVID-19 from the municipality of Ponta Grossa (Paraná State, Brazil), from April/2021 to February/2022, aiming to identify the Gamma, Delta, and Omicron variants, by RT-PCR, using specific probes. The Gamma variant was detected from April/2021 to September/2021. The Delta variant was subsequently detected from August/2021 to November/2021. The Omicron variant was the unique strain detected from December/2021 to February/2022 and, because of its high rate of transmissibility, it caused a considerable increase in the number of COVID-19 infections. Mass testing is considered an important strategy for COVID-19 control and, the correct detection of new strains, could improve the knowledge about the virus´ behavior, permitting the development of drugs and optimized vaccines.