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.

Presentation

In people with PCH, a polyclonal IgG anti-P 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.

Causes

PCH is a rare autoimmune haemolytic anaemia that can occur following an infection, when a microorganism triggers the formation of antibodies that cross-react with the P antigen on the red blood cell membrane (see article on the P antigen system). Viral infections that can cause PCH include measles, mumps, influenza, adenovirus, chickenpox, cytomegalovirus, and Epstein-Barr virus. Bacterial infections that can cause PCH include syphilis, Haemophilus influenzae and Mycoplasma pneumoniae. PCH can also be a side effect of some vaccinations. Chronic idiopathic (of unknown cause) PCH also occurs, but it is rare.

Treatment and prognosis

Acute PCH tends to be transient and self-limited,^[1] particularly in children. Chronic PCH associated with syphilis resolves after the syphilis is treated with appropriate antibiotics. Chronic idiopathic PCH is usually mild.

Risk factors

People with PCH are sometimes advised to avoid exposure to cold temperatures.^[2] If anemia is severe, blood transfusion may be needed. Careful compatibility testing by the blood bank is necessary because autoantibodies may interfere with blood typing. Prednisone may be used in individuals with PCH and severe anemia.

See also

• Hemolytic anemia
• Cold agglutinin disease
• List of hematologic conditions

References