Mini-review to analyse the phenotype, genotype, and alloantibody titre against Diego antigens in the Chinese population

Diego blood antigens are important antigens in Mongoloid people and native South Americans owing to the Dia positivity rate found in these populations. However, the prevalence of Di^a+ is different among native populations of America and China. Our study reviewed the genotype, phenotype, and alloantibody titre of Diego blood group antigens to explain the existence of the dosage effect for Diego antigens. The prevalence of Di^a+ varied from 2.26% to 10.43% in the Chinese population was lower than that observed in Native Americans living in USA, Brazil, and Venezuela. The Di(a+b-)/Di(a+b+) ratio in the Chinese was 0.0044~0.0268, which was also lower than that observed in native Americans at 0.0203–0.1628, indicating that the major allele was Di(a+b+) in Di^a+Chinese or Asians. We also collected Di(a+b-), Di(a+b+), and Di(a-b+) samples from Chinese samples to examine the agglutinin titres with anti-Di^a and anti-Di^b and the results supported the existence of the dosage effect for Diego antigens. The agglutinin titres of anti-Di^a in Di(a+b+) specimens were lower than those in Di(a+b-) specimens, and agglutinin titres of anti-Di^b in Di(a+b+) specimens were lower than those in Di(a-b+) specimens. Alloantibodies against Di^a and Di^b antigen are majorly responsible for haemolytic disease of the new-born and anti-Di^a reactions resulting in stillborn foetus and transfusion reactions, such as fever and rash,were also reported in the Chinese population.