MSFinals-2490
Sarah is a 19-year-old woman who visits her GP complaining of myalgia and fatigue. She has no significant medical history. In the past, she had a rash on her cheeks that did not improve with anti-fungal cream.
During the examination, her vital signs are normal, and there is no joint swelling or redness. However, she experiences tenderness when her hands are squeezed. Sarah’s muscle strength is 5/5 in all groups.
Sarah’s maternal aunt has been diagnosed with systemic lupus erythematosus (SLE), and she is worried that she might have it too.
Which of the following blood tests, if negative, can be a useful test to rule out SLE?