CRP and rheumatoid arthritis: Specifically, features such as reduced numbers of naive T cells and RTEs, as well as a raised IMM-AGE score and an inflammatory milieu (elevated systemic IL6, TNFα and CRP levels) are seen in patients with arthralgia and undifferentiated arthritis that may be contributing to creating a pre-disease microenvironment, but other features such as accumulation of senescent-like T cells are only seen at RA development.