Which of the following autoantibodies is highly specific for this patient\'s disorder?

A 36-year-old woman presents with a 4-month history of hand pain that is worse when awakening in the morning. She reports that her pain improves throughout the morning. Both hands are equally affected. Findings from a physical examination are shown in Figure. Which of the following autoantibodies is highly specific for this patient’s disorder?

  1. Anti-Smith antibodies
  2. Antihistone antibodies
  3. Anticentromere antibodies
  4. Anti-IgG antibodies
  5. Anti-citrullinated protein antibodies