A 23-year-old woman comes to the physician with migratory joint pains involving her hands and knees. Physical examination shows bilateral tenderness in her wrists and proximal interphalangeal joints. There is also a malar skin rash and generalized lymphadenopathy. A urinalysis reveals proteinuria. Further evaluation shows that the patient's lymphocytes contain a mutated and functionally defective Fas gene product. Which of the following immunologic mechanisms is most likely impaired in this patient as a result of this molecular defect?

Question

A 23-year-old woman comes to the physician with migratory joint pains involving her hands and knees.  Physical examination shows bilateral tenderness in her wrists and proximal interphalangeal joints.  There is also a malar skin rash and generalized lymphadenopathy.  A urinalysis reveals proteinuria.  Further evaluation shows that the patient's lymphocytes contain a mutated and functionally defective Fas gene product.  Which of the following immunologic mechanisms is most likely impaired in this patient as a result of this molecular defect?

Quizplus · Accepted Answer

Eductional Objective: The Fas receptor acts to initiate the extrinsic pathway of apoptosis.  Mutations involving the Fas receptor or Fas ligand can prevent apoptosis of autoreactive lymphocytes, thereby increasing the risk of autoimmune disorders such as systemic lupus erythematosus.

A 23-Year-Old Woman Comes to the Physician with Migratory Joint