Final answer:
During a flare-up of rheumatoid arthritis, an increased rheumatoid factor is typically observed in the blood of patients, as it correlates with the active phase of the autoimmune disorder.
Step-by-step explanation:
During a flare-up of rheumatoid arthritis (RA), an autoimmune disorder affecting the synovial joints, a blood test can measure various markers to assist in diagnosis and monitoring. Rheumatoid factor (RF) is one such marker, which is an antibody that may be found in the blood of individuals with RA. An increased rheumatoid factor is commonly seen in patients with this condition, especially during flare-ups when the immune system is highly active. A flare-up indicates the active phase of the disease, with an escalation of inflammation and immune system dysfunction, leading to higher levels of RF antibodies forming immune complexes. These immune complexes cause further inflammation in the joints, leading to increased pain and swelling.
Therefore, when a client with rheumatoid arthritis is having a flare-up of the disease, the expected result would be a(n) increased rheumatoid factor in their blood test. This is consistent with the disease's pathology, where the immune system creates antibodies such as RF that mistakenly target the body's own tissues, primarily affecting joints but also potentially other organs.