2026 Volume 33 Issue 2 Pages 72-80
Because HLA antigens possess multiple eplets, many of which are shared with other HLA antigens, anti-HLA antibodies exhibit complex reactivity. Even after sensitization to a single HLA antigen, multiple antibody specificities are often detected, since several eplets can serve as immunogens. Anti-HLA antibody testing has evolved from the LCT (Lymphocyte Cytotoxicity Test) method to the AHG-LCT (Anti-human Globulin Lymphocyte Cytotoxicity Test) method and LIFT-FCM (Lymphocyte Indirect Immunofluorescence Test-flow Cytometry), and has advanced further with the introduction of flow cytometry methods using purified HLA antigens and Luminex® fluorescent bead assays. In particular, the advent of single-antigen bead reagents has enabled eplet analysis of anti-HLA antibodies, thereby improving the accuracy of antibody specificity analysis. However, HLA antisera often contain a mixture of multiple antibody specificities, making it difficult to analyse individual eplets. To address this challenge, eplet analysis can be performed by isolating specific antibody specificities using adsorption-elution testing.
