Detection of Genetic Antigens utilizing Gamma Globulins coupled to Red Blood Cells

Abstract

THE genetic antigens of the human gamma globulin system have been detected primarily by a haemagglutination inhibition reaction¹. Anti-Gm or Inv antibodies from rare human sera are generally utilized in the test system together with Rh positive red cells coated by specific anti-Rh antibodies. This method has proved of considerable value but also has a number of important limitations. The finding that primate and rabbit antisera appropriately absorbed can replace the rare human sera eliminated one major defect in the system^2,3. A second major problem has been the dependence on selected anti-Rh antibodies containing the specific genetic antigen required for red cell coating. This problem has been brought to the fore in recent attempts to discover new genetic markers for the subgroups of IgG as well as for IgM and IgA. In many instances incomplete anti-Rh coats could not be found which contained the specific type of protein required. For example, the Gm (n) antigen⁴, which was delineated recently for the IgG2 class^* of proteins, could only be determined by relatively insensitive precipitation procedures because no suitable anti-Rh coat could be found.