A 45-year-old woman comes to the office due to a long history of joint pain, swelling, and stiffness. She recently immigrated to the United States and had little access to medical care in her original country. On physical examination, her proximal interphalangeal and metacarpophalangeal joints are tender and swollen bilaterally, and her fingers appear significantly deformed. Subcutaneous nodules are palpated near the elbow. Laboratory studies are obtained to confirm the diagnosis. This patient's serum is most likely to contain IgM antibodies against which of the following substances?

Question

A 45-year-old woman comes to the office due to a long history of joint pain, swelling, and stiffness.  She recently immigrated to the United States and had little access to medical care in her original country.  On physical examination, her proximal interphalangeal and metacarpophalangeal joints are tender and swollen bilaterally, and her fingers appear significantly deformed.  Subcutaneous nodules are palpated near the elbow.  Laboratory studies are obtained to confirm the diagnosis.  This patient's serum is most likely to contain IgM antibodies against which of the following substances?

Quizplus · Accepted Answer

Eductional Objective: Rheumatoid arthritis results from an immune response directed against autoantigens in the joints. Infiltrating CD4⁺ T cells secrete cytokines that promote inflammatory synovitis. They also stimulate B cells to produce rheumatoid factor (IgM antibody specific for Fc component of IgG) and anti-citrullinated protein antibodies that contribute to chronic inflammation and joint destruction.

A 45-Year-Old Woman Comes to the Office Due to a Long