The Role of Serology Testing in the Diagnostic Work-Up of Rheumatoid Arthritis

Abstract

The diagnosis of Rheumatoid Arthritis (RA) requires a combination of clinical, laboratory and imaging investigations. The ACR/EULAR classification criteria were presented in 2010 with the aim of improving the identification of individuals with RA. Because of its positive predictive value for RA, anticitrullinated peptide antibodies (ACPA) testing was newly introduced in the criteria in 2010, but with the same weight as the less specific test Rheumatoid Factor. This review addresses evidence, knowledge gaps, advantages and disadvantages of different laboratory testing paradigms in RA diagnosis. The goal is to support physicians in appreciating nuances of laboratory testing, to take informed decisions about who should be tested, when these tests should be utilized, and which tests are most appropriate for a diagnostic work-up.