title: Immunological tolerance in an HLA non-identical chimeric twin.
abstract: Blood group chimeric twins offer a unique opportunity to study immunological tolerance in humans. Although this condition is not as rare as previously considered, detailed immunological studies of blood group chimeras are lacking. We describe here a case of secondary chimerism in a dizygotic twin of opposite gender. The karyotypes of the cultured fibroblast confirmed the sex of each twin, all cells in the boy were 46, XY and all cells in the girl were 46, XX. Molecular HLA typing on fibroblasts revealed HLA-DR, DQ and DP disparities between the two siblings. Mixed lymphocyte culture (MLC) revealed a mutual absence of alloreactivity.
authors.affiliation: Department of Human Genetics, University Hospital Nijmegen, Nijmegen, The Netherlands. h.vietor@antrg.azn.nl
authors.forename: H E
authors.initials: HE
authors.lastname: Viëtor
authors.forename: B C
authors.initials: BC
authors.lastname: Hamel
authors.forename: S P
authors.initials: SP
authors.lastname: van Bree
authors.forename: E M
authors.initials: EM
authors.lastname: van der Meer
authors.forename: D F
authors.initials: DF
authors.lastname: Smeets
authors.forename: B J
authors.initials: BJ
authors.lastname: Otten
authors.forename: R A
authors.initials: RA
authors.lastname: Holl
authors.forename: F H
authors.initials: FH
authors.lastname: Claas
mesh_terms: D002678:Chimera / Q000276:immunology*; D005260:Female; D006680:HLA Antigens / Q000276:immunology*; D006650:Histocompatibility Testing; D006801:Humans; D007108:Immune Tolerance; D008297:Male; D011247:Pregnancy; D014429:Twins, Dizygotic
chemical_list: D006680:HLA Antigens