Antigen and Rh-positive

Antigen noun - Any substance (as a toxin or enzyme) that stimulates an immune response in the body (especially the production of antibodies).

Rh-positive and antigen are semantically related in blood group antigen topic. In some cases you can use "Rh-positive" instead a noun "Antigen".

Rh-positive adjective - Of persons (or their blood) having the Rh factor present in their red blood cells.

Antigen and Rh-positive are semantically related in blood group antigen topic. You can use "Antigen" instead a noun phrase "Rh-positive".