Human monoclonal antibodies to human blood group antigens Kidd Jka and Jkb

Summary. Three IgM human monoclonal antibodies to Jk^b, and one IgM human monoclonal antibody to Jk^a were produced from the lymphocytes of two immunized donors. Two of the anti-Jk^b monoclonal antibodies (MS-7 and MS-9) are of the IgM(κ) isotype and one (MS-8) is an IgM(λ). The anti-Jk^a monoclonal antibody (MS-15) is of the IgM(κ) isotype. They are all specific for their respective antigens, and give positive agglutinations in saline by the immediate spin technique, even against Jk(a + b +) cells. The heterohybridomas have been shown to be suitable for bulk culture and produce levels of antibody that reach 18 μg/ml in the spent culture supernatant. They offer considerable advantages over currently available reagents in terms of stability, simplicity and speed of use, and will provide a reliable and unlimited supply of what are at the moment rare and unsatisfactory antibodies.