The value of screening for autoantibodies in patients with non-specific symptoms.

An autoantibody screen is often requested in patients with non-specific symptoms such as pyrexia of unknown origin. However, in a survey of 100 consecutive requests for this investigation in such patients only one patient was encountered in whom the investigation led to a positive diagnosis at an estimated cost of pound 2500. These requests accounted for 5% of the total workload. These observations reaffirm that this should remain a second line investigation and should be deferred until more likely diagnoses have been excluded.