Autoimmune mechanismsDownloads

A 47-year-old woman comes to the physician because of progressive pain and stiffness in her hands and wrists for the past several months. Her hands are stiff in the morning; the stiffness improves as she starts her chores. Physical examination shows bilateral swelling and tenderness of the wrists, metacarpophalangeal joints, and proximal interphalangeal joints. Her range of motion is limited by pain. Laboratory studies show an increased erythrocyte sedimentation rate. This patient's condition is most likely associated with which of the following findings?

A 9-year-old boy is brought to your office due to nausea and vomiting. He had 4 episodes of non-bloody and non-bilious emesis over the last 24 hours. He denies any diarrhea or changes in his diet; however, his best friend at school recently had viral gastroenteritis and his mother is concerned that he has the same bug. She notes that he has been drinking more water than usual and wet his bed twice over the last two weeks. He is otherwise healthy and is not taking any medications. On physical exam his temperature is 99°F (37.2°C), blood pressure is 100/70 mmHg, pulse is 112/min, respirations are 26/min, and pulse oximetry is 99% on room air. He has lost 10 pounds since his previous visit 6 months ago. There is diffuse, mild abdominal tenderness to palpation. The most likely disease process responsible for this patient's symptoms is associated with which of the following?