When to order an antinuclear antibody testBMJ 2013; 347 doi: https://doi.org/10.1136/bmj.f5060 (Published 21 August 2013) Cite this as: BMJ 2013;347:f5060
- Allan Binder, consultant rheumatologist,
- Spencer Ellis, consultant rheumatologist
- 1Rheumatology, Lister Hospital, East and North Hertfordshire NHS Trust, Stevenage SG1 4AB, UK
- Correspondence to: A Binder
- Accepted 10 July 2013
Most patients with a positive test result for antinuclear antibody do not have systemic lupus erythematosus (SLE) or connective tissue disease, so antinuclear antibody testing should not be requested without a strong suspicion of autoimmune rheumatic disease
Clues from the clinical assessment such as photosensitivity, alopecia, Raynaud’s phenomenon, mouth ulcers, and arthritis should guide the need for testing for antinuclear antibody (and antibodies to extractable nuclear antigens)
Normochromic normocytic anaemia, neutropenia, lymphopenia, and thrombocytopenia are common findings in autoimmune rheumatic diseases
Although 95% of SLE patients are positive for antinuclear antibodies, the test specificity is only 57% for the disease
Antibodies to extractable nuclear antigens have a high specificity for particular clinical autoimmune features or complications
Urine analysis should always be undertaken when SLE is suspected
Antinuclear antibody titres cannot be used to monitor SLE and do not need to be repeated once a diagnosis is established. The best tests to serially monitor SLE activity are erythrocyte sedimentation rate, titres of antibodies to double stranded DNA, and complement levels
A 23 year old woman presents to her general practitioner with a three month history of malaise, fatigue, and arthralgia which she attributes to a viral illness. She had also attended the emergency department with pleuritic chest pain at the start of symptoms. She has had two miscarriages in the past, but has otherwise been healthy. On examination, there are small, non-tender lymph nodes in her neck and mildly swollen, tender, proximal interphalangeal joints in her hands.
What are the next investigations?
The presentation of systemic ill health, pleuritic chest pain, lymphadenopathy, and joint pain could follow a viral infection in addition to several differential diagnoses, including rheumatoid arthritis. However, with this collection of symptoms, it is important …