A 24-Year-Old Man Is Evaluated for Recurrent Episodes of Abdominal

question 515

Multiple Choice

A 24-year-old man is evaluated for recurrent episodes of abdominal pain and bloody diarrhea.  The patient has also had low-grade fevers and fatigue.  Physical examination reveals left lower quadrant tenderness.  CT scan of the abdomen shows thickening of the distal colon and rectum.  During one of the laboratory tests, the patient's anticoagulated blood is placed in an upright, thin glass tube and left undisturbed.  His red blood cells form a stack and settle to the bottom at a fast rate of 50 mm/hr.  Serum levels of which of the following substances is most closely associated with this observed finding?

• A)Bradykinin
• B)Erythropoietin
• C)Interleukin (IL)-6
• D)Leukotriene B₄
• E)Platelet-activating factor
• F)Thromboxane A₂