Fast Five Quiz: Paroxysmal Nocturnal Hemoglobinuria Management

John L. Reagan, MD


March 29, 2023

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare, chronic, debilitating disorder that most frequently presents in early adulthood and usually continues throughout the patient's life. PNH results in the death of approximately 50% of affected individuals due to thrombotic complications. Until recently there was no specific therapy for PNH.

The name of the disorder is a descriptive term for the clinical consequence of red blood cell (RBC) breakdown with release of hemoglobin into the urine, which can manifest as dark-colored urine at any point but classically occurs in the morning.

The term "nocturnal" refers to the belief that hemolysis is triggered by acidosis during sleep and activates complement to hemolyze an unprotected and abnormal RBC membrane. However, hemolysis has been shown to occur throughout the day and is not actually paroxysmal. The concentration of urine overnight produces the dramatic change in color.

PNH has been referred to as "the great impersonator" because of the variety of symptoms observed during its initial manifestation and course. The triad of hemolytic anemia, pancytopenia, and thrombosis makes PNH a unique clinical syndrome.

How much do you know about the management of PNH? Test your knowledge with this quick quiz.


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