Human haemoclassification by use of specific yolk antibodies obtained after immunisation of chickens against human blood group antigens

Polyclonal antibodies, widely used in research and diagnostics, are convent ionally isolated from the blood of immunised mammals, especially rabbits. T he fact that antibodies can also be detected in the yolk of eggs laid by im munised hens, led to the development of yolk antibody technology (IgY-techn ology) as an alternative method that is less stressful to animals. This tec hnology has become a worthwhile alternative to the blood-dependent techniqu es. Furthermore, because of the phylogenetic distance between birds and mam mals, avian antigens have a very specific immune response to highly conserv ed antigens of mammals, such as human erythrocyte antigens. To evaluate the humoral immune response of hens immunised with human red erythrocyte antig ens, 22 White Leghorn hens were kept in cages and immunised with total red blood cells or stroma of the human rhesus positive (Rh+) system (D antigen) by weekly intramuscular and intravenous injections, without the use of an adjuvant. The haemagglutination assay was used to evaluate the dynamics of the production of IgY antibodies against human erythrocyte antigens, and si ngle radial immunodiffusion was used to evaluate the amount of total IgY in de-lipidated supernatants from egg yolk. The highest titres were observed four weeks after the first immunisation, and these remained stable for up t o seven weeks for the intravenous route. Positive reactivity against human erythrocyte antigens A, B and O was demonstrated in de-lipidated supernatan ts from the egg yolks of immunised hens. The strongest reaction was observe d against blood group O Rh+ (O+). Furthermore, the antibodies obtained reco gnised erythrocyte antigens that belong to neither the Rh system nor the La ndsteiner-Weiner antigen. This finding opens the possibility of using hens instead of rabbits to produce polyclonal antibodies for human haemoclassifi cation.