Another reader question:
Where can I find the result of an RA test in my lab paper?
Different laboratories format their reports differently, so the location of the information you want will vary. Nobody can say “look at the fourth line down” for a specific test. You probably have to slog through a lot of information to figure out what’s going on.
To complicate matters, there isn’t one specific test for RA. Doctors can order a CBC and say with some degree of certainty, “your white count is ___.” They can’t do that with RA. There is no test (or group of tests) that can be ordered that will tell the doctor with certainty that a person does or doesn’t have RA. When you hear that RA is a clinical diagnosis, that’s what it means – the diagnosis is made in the clinic, not the laboratory.
Your doctor is a clinician who must take a careful history, perform a detailed examination, then based on the evidence can try to determine what’s going on. The diagnostic criteria for RA has changed. In the past, people had to be well along the road to permanent joint damage before they could get a diagnosis. The goal now is to diagnose early and treat aggressively enough that damage visible on x-rays never occurs. I am highly in favor of early diagnosis!
Lab tests are part of the diagnostic criteria, but seronegative RA can be diagnosed with completely normal lab results if symptoms have lasted longer than six weeks and there are more than ten joints involved (as long as at least one is a small joint). Seropositive RA means that lab tests (RF or CCP) support the diagnosis. Tests that might be ordered if an autoimmune disease is suspected:
- Rheumatoid Factor (RF)
- Anti-Cyclic Citrullinated Peptide Antibody (CCP)
- Erythrocyte Sedimentation Rate (ESR)
- C-Reactive Protein (CRP)
- Antinuclear Antibody (ANA)
- Complements (C3, C4, etc.)
It is not appropriate to tell your doctor to order a specific test. I wouldn’t much care for it if a client walked in off the street and told me how to do my job, and you probably wouldn’t either. That makes it pretty easy to understand the doctor’s point of view on this. You don’t have to read very many medblogs before you discover (if it isn’t intuitively obvious) that doctors don’t appreciate people telling them which tests to order. Just explain your symptoms and let the doctor do his job.
There’s a small sticky-point here. RA can be hard to diagnose. Some doctors don’t realize that RF is negative in many people with early RA. The CCP test is relatively new, and doctors who didn’t specialize in rheumatology might not know about it. A doctor might suspect RA, order a test for rheumatoid factor, and not realize that there’s more to diagnosing RA. This is where it pays to have a good relationship with your primary doctor so that you can return for follow-up without being blown off as a hypochondriac (unless you are one). If you’re concerned about something, don’t make your doctor guess; say so.