In cases of suspected rheumatoid arthritis, which laboratory test is specifically recommended to confirm diagnosis?

The presence of anti-citrullinated protein antibodies (Anti-CCP antibodies) is a crucial marker specifically associated with rheumatoid arthritis. Testing for anti-CCP antibodies offers a higher specificity for diagnosing rheumatoid arthritis compared to other tests, making it particularly useful in confirming the diagnosis. These antibodies can be detected in the blood even in the early stages of the disease, often before the appearance of clinical symptoms. This early detection is significant as it can allow for timely intervention and better management of the disease, potentially leading to improved patient outcomes.

Complete blood count, while useful for evaluating general health and detecting anemia or inflammation, is not specific for rheumatoid arthritis. The ANA test is typically used to screen for autoimmune disorders but does not specifically indicate rheumatoid arthritis. Immunofixation electrophoresis is used primarily for the detection of monoclonal proteins and is not relevant for diagnosing rheumatoid arthritis. Thus, testing for anti-CCP antibodies stands out as the recommended laboratory test when rheumatoid arthritis is suspected.