A young woman presents with a facial rash, arthralgias, and fatigue. The rash on her face is erythematous and raised, her heart and lungs are normal, and wrists are swollen and tender on palpation. She has mild thrombocytopenia (90,000/mL). Which of the following is the most appropriate initial autoantibody test?
High-Yield Explanation
ANA is the most important diagnostic autoantibodies in patients being evaluated for SLE. It is rare to have ANA negative SLE. The other antibodies can occur in SLE but not as sensitive for the diagnosis as ANA. Anti-dsDNA and anti-SM are specific for SLE but not sensitive.