The value of autoantibody testing in a central triage system

Abstract

The referral of patients with positive anti-nuclear antibody (ANA) tests to specialists has been criticised as an inappropriate use of tertiary care resources. On the other hand, an accurate and timely diagnosis in patients with a positive ANA and protean symptoms can lead to improved health outcomes while reducing health care costs. In order to address this apparent paradox, we studied the serological profiles and clinical diagnoses of patients referred to rheumatologists through a regional triage system because of a positive ANA or extractable nuclear antibody (ENA) test. As an approach to informing an evidence based approach to triage, the primary objectives were to document the most common ANA specificities, the presence of anti-dense fine speckled (DFS70) antibodies and the specialist’s clinical opinion. The spectrum of autoantibody specificities was wide with anti-Ro52/TRIM21, which has been established as a biomarker for SARD, being the most common autoantibody detected. In addition, some referred patients had only antibodies to DFS70, the majority of which did not have clinical evidence for a definite diagnosis of a SARD. This study implies that there is value in determining autoantibody specificity in a rheumatology triage service by providing a general guideline to referrals that require urgent versus less urgent attention.