P ANTIGEN

P antigen: translation

Antigenic determinant on the surface of human red blood cells to which the Donath-Landsteiner antibody reacts. This antibody binds in the cold (a "cold IgG"), but elutes from red cells at 37°C, is particularly associated with tertiary syphylis, and its binding causes paroxysmal nocturnal haemoglobinuria. (See also decay accelerating factor).