Final answer:
The presence of a positive rheumatoid factor is not always indicative of rheumatoid arthritis, as it can also be associated with other conditions or be present in healthy individuals. A combination of symptoms, blood tests, and imaging studies are used for diagnosis.
Step-by-step explanation:
The statement that the presence of a positive rheumatoid factor (RF) is always indicative of rheumatoid arthritis (RA) is false. While RF can be a marker for RA, it can also be present in a variety of other diseases and conditions such as Sjögren's syndrome, systemic lupus erythematosus, and chronic infections. Additionally, some healthy individuals may have a positive RF without any clinical symptoms of disease. Therefore, the diagnosis of RA relies on a combination of clinical symptoms such as joint inflammation and pain, and diagnostic tests including blood tests for RF, anti-cyclic citrullinated peptide (anti-CCP) antibodies, and imaging studies like X-ray, MRI, and arthrography.
RA is a chronic inflammatory joint disease that involves type III hypersensitivity reactions and the activation of CD4 T cells, leading to chronic release of inflammatory cytokines and joint damage. However, since RF is not exclusively associated with RA, rheumatologists consider a broader spectrum of signs, symptoms, and test results when diagnosing the condition.