QuestionSBA
QuestionChoice
ANA is the most sensitive test for SLE. However, is not the most specific test, as it is also present in a number of other connective tissue diseases. It is not diagnostic in itself but does make up a key part of the workup for an SLE diagnosis. A negative test can relatively reliably rule out SLE.
10006801
a
Antinuclear antibody (ANA)
QuestionChoice
Anti-TPO is the primary antibody detected in patients with Graves' disease. It prevents the breakdown of thyroid hormone resulting in excessive free T4/T3- leading to signs of thyrotoxicosis.
10006805
e
Anti-thyroperoxidase (anti-TPO) antibodies
QuestionChoice
Anti-dsDNA is a highly specific test for SLE. However, it is only found in about 60% of patients with SLE. It can be used as a confirmatory blood test following a positive ANA result. High levels of anti-dsDNA have also been linked to greater disease activity, and therefore this test plays a role in determining the severity of the condition.
10006802
b
Anti-double-stranded DNA (anti-dsDNA)
QuestionChoice
Anti-smith antigen is another highly specific test for SLE, but is not as sensitive. It has a role in confirming an SLE diagnosis following a positive ANA result.
10006804
d
Anti-smith antigen
QuestionChoice
Anti-CCP is the primary blood marker used in the diagnosis of rheumatoid arthritis. However, it is less likely to be raised in SLE.
10006803
c
Anti-CCP
Concept
Chapter
2693
4544
Systemic lupus erythematous (SLE)
Topic
146
Rheumatology
13907
A 34-year-old woman presents to her GP complaining of a mild fever, fatigue, and weight loss over the past two weeks. She is noted to be limping slightly and, when asked, she mentions that she has had pain in her left knee. She has a past medical history of Raynaud's syndrome, and her only medication is the combined oral contraceptive pill. On examination, the GP notes a malar rash on her cheeks. Systemic lupus erythematosus (SLE) is suspected.

Which of the following blood tests is most sensitive for the likely diagnosis?
a