A 26-year-old African American woman comes to the physician because of a 4-day history of a nonproductive cough and chest pain. The pain is sharp and worse when she breathes deeply. During this time, she has also had two episodes of hematuria. Over the past 6 months, she has had intermittent pain, stiffness, and swelling in her fingers and left knee. She is sexually active with one male partner and uses an intrauterine device for contraception.Temperature is 38.3 C (100.9 F), blood pressure is 120/70 mm Hg, pulse is 89/min, and respirations are 18/min. Physical examination shows an erythematous rash on her face. There is mild tenderness over the metacarpophalangeal joints bilaterally with no warmth or erythema. Which of the following tests is most useful in confirming the diagnosis?

Question

A 26-year-old African American woman comes to the physician because of a 4-day history of a nonproductive cough and chest pain. The pain is sharp and worse when she breathes deeply. During this time, she has also had two episodes of hematuria. Over the past 6 months, she has had intermittent pain, stiffness, and swelling in her fingers and left knee. She is sexually active with one male partner and uses an intrauterine device for contraception.Temperature is 38.3 C (100.9 F), blood pressure is 120/70 mm Hg, pulse is 89/min, and respirations are 18/min.  Physical examination shows an erythematous rash on her face. There is mild tenderness over the metacarpophalangeal joints bilaterally with no warmth or erythema. Which of the following tests is most useful in confirming the diagnosis?

Quizplus · Accepted Answer

Eductional Objective: Antinuclear antibodies are found in almost all patients with systemic lupus erythematosus but are also found in many other autoimmune disorders and have low specificity.  Anti-double-stranded DNA antibodies and anti-Smith antibodies have lower sensitivity but higher specificity.

A 26-Year-Old African American Woman Comes to the Physician Because