Definition for paroxysmal cold hemoglobinuria

Paroxysmal cold hemoglobinuria (PCH) (also known as Donath-Landsteiner syndrome) is a disease of humans that is characterized by the sudden presence of hemoglobin in the urine (called hemoglobinuria), typically after exposure to cold temperatures.

In people with PCH, a polyclonal IgG autoantibody binds to red blood cell surface antigens in the cold. This can occur in a susceptible individual as blood passes through cold extremities in cold weather. When the blood returns to the warmer central circulation, the red blood cells are lysed with complement, causing intravascular hemolysis. Hemoglobinuria and anemia can then occur. The anemia may be mild or severe. less