Alterations of glycosphingolipid-based blood group antigen expression on erythrocytes and in plasma studied on consecutive samples after a blood group O to A bone marrow transplantation.

A blood group A1Le(a-b+) individual with chronic myeloid leukaemia had received a bone marrow graft from an HLA-identical OLe(a+b-) donor. Twelve months after bone marrow transplantation (BMT), the red blood cells of the patient became agglutinable with anti-A blood group reagents. To elucidate whether the blood group A antigen expression was of plasma or of bone marrow origin, total non-acid glycosphingolipid fractions were prepared from red blood cells and plasma collected 17 months after BMT, and from plasma collected 13, 15 and 19 weeks after BMT. The glycolipid fractions were analysed by thin-layer chromatography and immunostained with monoclonal A-antibodies, and permethylated and permethylated-reduced derivatives of selected plasma samples were analysed by mass spectrometry. The results strongly indicate the presence of host bone marrow-produced blood group A red blood cells. Furthermore, the presence of a blood group H active pentaglycosylceramide type 1 (H-5-1) (Table I), characteristic for an OLe(a-b-) secretor, was seen in plasma 3-4 weeks before clinical chronic graft versus host disease (GVHD). After treatment of chronic GVHD, this expression disappeared. The blood group ALeb (A-7-1) antigen produced by the recipient seems to be present and to increase with time in all plasma samples. This also seems to be the case for the Leb and A-6-1 antigens.