Leukocyte Antigen Typing Research Articles

Horizontal nonparenteral spread of hepatitis B among children.

Two families with an unusually high incidence of hepatitis B infection (15 of 21 persons) were investigated over an 18-month period. Serologic evidence of past or present infection--hepatitis B surface antigen (HBsAg), antibody to hepatitis B surface antigen (anti-HBs), or antibody to hepatitis B core antigen (anti-HBc)--was found in 11 of the 12 members of one family, four of whom were chronic HBsAg carriers, and in four of nine members of a contact family. Anti-HBc was the only serologic marker of infection in five persons. Histocompatibility leukocyte antigen (HLA) typing failed to show an association between carriage of HBsAg and specific HLA markers. Chewing gum was a potential vehicle as HBsAg was detected in gum samples from three of four children who were chronic HBsAg carriers. Horizontal, nonparenteral transmission of hepatitis B virus probably accounted for the clustering of infection in these families, especially via the exchange among children of objects contaminated with oral secretions.

Another Example of Human Chimerism

Routine blood typing demonstrated two populations of red blood cells in a dizygotic female twin. Approximately 30 per cent of the red blood cells are A1B, MS/Ns, cde/cde and 70 per cent are O/O, Ns/Ns, CDue/cde. Red blood cell typing and secretor tests on the family showed the minor population to be the true genetic cell line of the propositus. Further evidence of chimerism is revealed by the presence of both XX and XY karyotypes. Tissue cultures showed only XX, lymphocyte cultures only XY, and buccal smears were chromatin positive. There was no evidence of two populations of white blood cells by leukocyte antigen typing. Comparative studies of the male twin were impossible because of his death three months prior to this discovery; however, he was reported by the Armed Services to the AB, Rh negative and we presume he had a mixture of A1B and O cells and that he was genetically group O.