TSEN: a novel MNS-related blood group antigen.

We report an antibody (anti-TSEN) that recognizes an antigen (TSEN) at the unique amino acid sequence that results from the junction of GPA58 to GPB27 if the GPB carries the S antigen. Red cells from several unrelated donors that possess this specific GP(A-B) hybrid molecule were agglutinated by anti-TSEN. Since a synthetic peptide with the amino acid sequence at this junction (Pro-Glu-Glu-Glu-Thr-Gly-Glu-Met-Gly-Gln-Leu-Val-His-Arg) specifically inhibited anti-TSEN, it must detect an antigen within this novel amino acid sequence.

Synthetic peptides homologous to human glycophorins of the Miltenberger complex of variants of MNSs blood group system specify the epitopes for Hil, SJL, Hop, and Mur antisera.

The antigenic epitopes of the MNSs blood groups are localized on alpha and delta glycophorins (glycophorins A and B) of the erythrocyte surface. Hil, SJL, Mur, and Hop antisera define the Miltenberger (Mi) complex of MiV, MiJ.L.

Two cases of "hrB-like" autoantibodies appearing as alloantibodies.

Two cases are described in which autoantibodies mimicked alloantibodies. The direct antiglobulin test (DAT) on the red cells (RBCs) from both patients was negative when routine manual hexadimethrine bromide (Polybrene) and enzyme-linked antiglobulin techniques were used. The RBCs also did not react on direct bromelin and direct Polybrene tests.

Autoanti-Ge associated with severe autoimmune hemolytic anemia.

Severe autoimmune hemolytic anemia due to anti-Ge is described. The patient's red cells had a positive direct antiglobulin test, and they typed as Ge+ using saline reactive reagents. Anti-Ge was eluted from her RBCs, and her serum had an IgG and IgM anti-Ge2,3.