Case Study: The trouble with diagnosing lupus

The antinuclear antibody test is poorly discriminating and should be used with caution in diagnosing lupus.

Bernard is a 54-year-old accountant, who regularly attends his GP and is worried about his health.


He describes joint pain and, when questioned, points to the DIP and PIP (distal and proximal interphalangeal) joints of his fingers. He does not think that they have been swollen.

He is concerned because he recalls his mother having "knobbly joints" and fears the same problem.

He has a medical history of hypertension, appendicectomy and irritable bowel syndrome. He takes irbesartan 150mg for hypertension. He denies other symptoms.