The presentation of polymyalgic symptoms in elderly patients represents a challenging issue since a number of inflammatory disorders may mimic polymyalgia rheumatica (PMR), a clinical syndrome characterized by pain and stiffness in proximal areas that affects people older than 50 years. The differential diagnosis between PMR and elderly-onset rheumatoid arthritis (EORA) may be very difficult, especially at the onset of the clinical picture. Although progress in the development of imaging has been done, there is a lack of specific laboratory biomarkers to differentiate PMR from EORA. Both syndromes are characterized by elevation of acute phase reactants, such as CRP and ESR, and inflammatory cytokines, such as IL-6. The most helpful laboratory parameter has been recently defined as the lack of anti-CCP antibodies, which increases the likelihood of PMR. We will present laboratory data demonstrating that PMR could be considered as part of the natural history of EORA. At present, the higher prevalence of seronegative EORA compared with adult onset RA may be more related with our inability to detect specific autoantibodies than with the real absence of serum autoantibodies. We will present data of new biomarkers that may help to identify an important number of seronegative EORA patients and to diagnose EORA in patients with clinical suspicion of PMR.
Disclosure of Interest None declared