Analysis of the effectiveness of the use of molecular genetic typing to determine the phenotype of patients with chimerism by rhesus erythrocyte antigens

Transfusions of blood components, both single and multiple, are widely used in the treatment of hematological diseases. Transfusions of donor erythrocytes are not always carried out "phenotype to phenotype". It leads to the identification of double populations (chimeras) of erythrocyte antigens in the recipient's blood when determining the phenotype by agglutination in gel. Unreliable results may cause errors in the selection of donor erythrocytes and lead to alloimmunization. With the following transfusions, the risk of posttransfusion complications of the hemolytic type increases. The solution to the problem may be the use of molecular genetic typing. The aim of the study was use molecular genetic typing to determine patient phenotype to prevent errors in the selection of donor erythrocytes and to analyze the occurrence of chimeras after transfusion therapy into account the recipient genotype. In 2019-2022 chimeras of the antigens C, c, E, e were detected in 129 (7.4%) patients out of 1737 primary hospitalized persons with hematological diseases by the method of agglutination in gel. These patients were genotyped, the discrepancy between the results of the molecular genetic method and the method of agglutination in gel was 66 cases (51.2%). Transfusions of erythrocytes to patients of the study group were performed into account the genotype. With subsequent hospitalizations in 2020 – 2021 – 2022 the number of patients with chimerism decreased accordingly 77,8 – 50,0 – 36,0 %. Alloantibodies were not found in any of the 129 patients. Molecular genetic typing allowed us to obtain a reliable result. The absence of double populations and alloantibodies proves the effectiveness of the use of molecular genetic methods in the selection of donor erythrocytes for transfusions.