title: [Polyagglutinability due to Hempas antigen].
abstract: A new antigen has been recently discoverd in patients with congenital dyserythropoietic anemia type II. The acronyme Hempas was proposed for this disease as a remind of the main morphological feature of erythroblasts (hereditary erythroblastic multinuclearity) and the characteristic serological findings (positive acidified serum test). The patients red cells are agglutinated and lysed by an IgM cold reacting antibody present in the serum of most normal subjects and not previously recognized. This behaviour is thus reminding of cells carrying antigens such as T, Tn, Cad or acquired B. As for T and Tn cells, sialic acid and electrophoretic mobility are reduced, but in contrast, agglutinability of Hempas cells is enhanced by enzyme treatment. Agglutination by anti H and anti Pr specific reagents is reduced. I and mainly i activity are strongly increased. The relationship between the membrane abnormalities of Hempas red cells and the failure of normoblasts to divide their cytoplasm i still largely unknown.
mesh_terms: D003165:Complement System Proteins / Q000378:metabolism; D004900:Erythroblasts / Q000166:cytology; D005260:Female; D006384:Hemagglutination; D006461:Hemolysis; D006801:Humans; D007048:I Blood-Group System; D008297:Male; D010447:Peptide Hydrolases / Q000494:pharmacology; D013789:Thalassemia / Q000151:congenital / Q000276:immunology / Q000503:physiopathology*
chemical_list: D007048:I Blood-Group System; D003165:Complement System Proteins; D010447:Peptide Hydrolases
vernacular_title: Polyagglutinabilité due à l'antigène Hempas