Seronegative arthritis

Abstract

The inflammatory arthritides are often divided into those that are ‘seropositive’ and those that are ‘seronegative’. The former test positive with blood tests that look for two proteins: rheumatoid factor; and anti-cyclic citrullinated peptide antibody. However, although seropositivity is part of the diagnostic criteria for rheumatoid arthritis (RA), seronegativity does not exclude the diagnosis, but rather suggests a more benign disease. The term ‘seronegative arthritis’ has evolved from a term used to describe variants of RA, to the present understanding of a spectrum of ‘seronegative spondyloarthritides’ (defined as inflammation within the axial skeleton and vertebral column). These are a closely linked group of conditions with common serological, genetic, clinical and radiological features. These include: ankylosing spondylitis; juvenile ankylosing spondylitis; psoriatic arthritis; reactive arthritis; enteropathic arthritis; undifferentiated spondyloarthritis; and seronegative enthesopathic arthritis syndrome. This article will outline the diagnosis and management of seronegative arthritis.