Terminology used to describe the natural history of RA.
Term | Definition |
---|---|
Pre-RA, preclinical RA | The stage prior to the development of clinical RA. May be defined in several ways, including presence of autoantibodies, abnormal symptoms, and imaging findings. |
At-risk | Any state in which an individual has a higher-than-average risk of developing RA but does not have current IA (ie, being an FDR of a patient with RA, presence of autoantibodies). Notably, a EULAR task force that included individuals with clinical RA, as well as individuals who are at-risk for future RA, determined that the term “pre-RA” should only be used retrospectively once it was known that an individual developed clinical RA.32 As such, the term “at-risk individual” is often used to describe individuals who exhibit some risk factors for future RA but whose future status of clinical RA is unknown. |
First-degree relative (FDR) | An individual who is related in the first degree (ie, parent, full sibling, offspring) to an individual with a specific disease. An FDR shares genetic and often environmental risk factors for developing the disease of interest. |
Clinically suspect arthralgia (CSA) | A combination of signs and symptoms that is suggestive of the presence and/or risk for IA. This includes, but is not limited to, morning stiffness and pain in the small joints. The pain may or may not be elicited on physical examination. |
Clinically apparent IA | A clinical finding of joint synovitis in the absence of trauma that is suggestive of the earliest stage of RA. A joint with synovitis is typically tender on range of motion/palpation, swollen with a palpable effusion, and warmer than noninflamed joints. |
Palindromic rheumatism (PR) | Recurrent episodes of IA, typically involving the small joints of the hands and feet, that resolves spontaneously with limited or no symptoms between events. A subset of patients with PR will develop classifiable RA. |
Subclinical IA | The presence of inflammation in a joint detected by imaging, typically by MRI or US, that is suggestive of IA, and a physical examination of the involved joint that is not suggestive of synovitis (ie, there is an absence of joint swelling). |
Undifferentiated arthritis | IA that does not fulfill established classification criteria for RA or any other disease. |
Clinical RA | Clinically apparent IA, with or without autoantibodies, that a clinician diagnoses and treats as RA. This includes individuals who have classifiable RA and those who do not. For example, a patient with low positive ACPA/RF and 3 swollen small joints may not have classifiable RA but still be diagnosed and treated as having RA. |
Classifiable RA | A patient who meets established classification criteria for RA, either the 1987 ACR or 2010 ACR/EULAR criteria.1,2 |
Seropositive RA | Clinical RA with serum elevations of RA-associated antibodies, such as RF or ACPA. |
Seronegative RA | Clinical RA without serum elevations of RA-associated antibodies, such as RF or ACPA. |
Early RA | A patient who meets classification criteria for RA for a short duration, typically < 1 yr, although definitions vary in the literature. |
ACPA: anticitrullinated protein antibody; ACR: American College of Rheumatology; CRP: C-reactive protein; EULAR: European Alliance of Associations for Rheumatology; IA: inflammatory arthritis; MRI: magnetic resonance imaging; RA: rheumatoid arthritis; RF: rheumatoid factor; US: ultrasound.