A patient is diagnosed with a rare coagulation disorder known as paroxysmal nocturnal hemoglobinuria (PNH). Which of the following is a characteristic feature of this condition?

A Deficiency of factor VIII
B Presence of schistocytes on peripheral smear
C Increased susceptibility to venous thrombosis due to deficiency of CD55 and CD59 on blood cells ✓
D Elevation of D-dimer levels

Explanation

Paroxysmal nocturnal hemoglobinuria (PNH) is characterized by the deficiency of CD55 and CD59 on the surface of blood cells, leading to increased complement activation and a propensity for venous thrombosis.

Source

Harrison's Principles of Internal Medicine
Hematology Hematology: Coagulation Disorders Hematology: Coagulation Disorders Hard MEDICAL Confidence: high