Paroxysmal cold hemoglobinuria due to an IgA Donath-Landsteiner antibody.

Paroxysmal cold hemoglobinuria (PCH) is an autoimmune hemolytic anemia (AIHA) characterized by the presence of a Donath-Landsteiner (D-L) antibody. PCH occurs most commonly in young children and is associated with acute, often self-limited hemolytic anemia. The D-L antibody is classically a biphasic IgG anti-P autoantibody identified by the D-L test.