Paroxysmal cold hemoglobinuria (PCH) is often associated with which antibody?

Paroxysmal cold hemoglobinuria (PCH) is often associated with which antibody?

• A. anti-P
• B. anti-K
• C. anti-N
• D. anti-Lea

Answer: (A)

Paroxysmal cold hemoglobinuria is driven by a biphasic IgG autoantibody that targets the P red cell antigen. The Donath-Landsteiner antibody binds to red cells in the cold, fixes complement, and then causes intravascular hemolysis when the cells are warmed to body temperature. This cold-induced binding and subsequent warming-triggered lysis describe the episodic hemolysis seen in PCH, making anti-P the classic antibody associated with this condition. Other choices target different red cell antigens (Kell, MNS, Lewis) and are not linked to the P antigen–mediated mechanism of PCH.

Paroxysmal cold hemoglobinuria is driven by a biphasic IgG autoantibody that targets the P red cell antigen. The Donath-Landsteiner antibody binds to red cells in the cold, fixes complement, and then causes intravascular hemolysis when the cells are warmed to body temperature. This cold-induced binding and subsequent warming-triggered lysis describe the episodic hemolysis seen in PCH, making anti-P the classic antibody associated with this condition. Other choices target different red cell antigens (Kell, MNS, Lewis) and are not linked to the P antigen–mediated mechanism of PCH.