I joined an online support group some 4,000 members strong for RA last week and I was astounded at the number of posts in which a member says, “I don’t understand why my joints hurt so much. All my labs were normal” followed by some indication that they have been told they do not have RA. This frustrates me because these new patients are led to believe by their medical team, which sometimes includes a rheumatologist, that their symptoms are all in their heads when the pain and fatigue are very real. I just don’t understand why more doctors do not recognize Sero-Negative Rheumatoid Arthritis (S-RA). The Arthritis Foundation calculates that at least 20-30% of RA patients fall into the S-RA category, meaning they have a normal blood Rheumatoid Factor and ANA. These blood lab tests alone should never been a used to diagnose this disease because they are misleading. There is a good percentage of healthy adults who have a positive Rheumatoid Factor; which renders the result inconclusive. I’ve had S-RA for 4 years now. Blood samples drawn throughout this four-year period all have a negative blood Rheumatoid Factor and a normal ANA; however, my CRP and ESR have always been elevated and keep climbing without being checked by any treatment to date.
I wanted to write this blog about S-RA so that the layperson will know what goes into diagnosing this category of autoimmune disease and to try to sort fact from the fiction some of you have been led to believe. S-RA is treated just like RA. Your treatment plan could be delayed by years resulting in permanent joint damage if not diagnosed early.
Labs – Your physician may order these labs on your first appointment for diagnosis and afterwards to monitor your disease. Don’t be afraid to look at your lab reports. They are laid out fairly simple with a normal range so you can tell which of your labs results are abnormal. With the use of the internet you can find more information about your lab results that is written in laymen terms.
- The Rheumatoid Factor is no longer the gold standard used to diagnose RA. It is inconclusive. As I mentioned above, healthy individuals sometimes test positive for the RA Factor and science does not know why. Conversely, there are about 20-30% of the rheumatoid patient population who have a negative Rheumatoid Factor but indeed to have RA. The rheumatoid factor is a protein in the blood that is made by the autoimmune system.
- The ANA (Anti-Nuclear Antibodies) blood test shows the number of these antibodies that you have in your blood. This test is also inconclusive as healthy people have tested with elevated ANA for no reason. The antibodies are made by the autoimmune system. When it is elevated it can signal lupus, rheumatoid arthritis or scleroderma but it should not be used alone as a diagnostic tool.
- CRP (C-Reactive Protein) is a blood test for this protein that appears in high numbers when there is inflammation in the body. The inflammatory response isn’t specified to autoimmune disease but can be caused by a injury, post surgery, or due to cardiac disease.
- ESR (Erythrocyte Sedimentation Rate) or Sed Rate is another lab test that measures inflammation in the body. Is not a stand alone test, but is used with other tests to support a diagnosis. This is a test in which your blood sample is placed in a small tube for 1 hour. It measures the rate at which erythrocytes (red blood cells) fall in the tube. Inflammation causes the erythrocytes to clump together which causes them to fall at a faster rate. The Sed Rate measures how fast the erythrocytes fall to the bottom of the tube. The higher the number, the more inflammation there is in the body.
- Anti-CCP or ACCP (Anti-Cyclic Citrullinated Peptide) is an antibody that can be found in the blood that is a better marker for RA than the Rheumatoid Factor. A patient can have a negative Rheumatoid Factor but still be positive for the ACCP. However, again, this is not a definitive test. People are genetically predisposition to have this antibody while others do not. There is a strong correlation that those who do have the antibody present in their blood do have RA.
- Vectra DA – The Vectra DA blood test is a newer test that measures 12 different bio-markers in the blood and computes a single sore for these markers that range in categories of high disease activity, moderate disease activity or low disease activity. It can be used by your doctor over time to see if there is an overall improvement or worsening of your disease. Again, this disease may not be conclusive for S-RA.
Radiology – X-rays, CAT Scans, MRI’s, Ultrasound, and Bone Scans can be used in the diagnosis of RA. When used in combination with lab testing they help your physician make a better diagnosis.
- X-Rays of Bones – A routine x-ray can be helpful if you already have a gross deformity of joints but it is not practical in picking up fine bone erosion associated with RA. In fact, the radiologist reading they film may mistakenly see osteoarthritis changes (OA) which can occur secondary to RA.
- Joint Ultrasound – Ultrasound of the effected joint can show damage before a routine x-ray.
- CAT Scan – CAT Scans are more powerful than xrays. The CAT Scan takes pictures in slices either vertically or horizontally and can show details within these layers that are not available on xray.
- MRI Scan – A MRI uses radio-frequencies, strong magnets, and a computer to show detailed images of body structures.
- DEXA Scan or Bone Density Test – A test that is used to diagnose the likelihood or presence of osteopenia or osteoperosis.
- Bone Scintigram – This is a nuclear bone test in which a radio-isotope is injected in the patient. Later, the patient is scanned with gamma camera and areas of bone that have taken up the isotope are considered to be in a state intense remodeling which is not seen in osteoporosis but seen in rheumatoid arthritis and bone cancer.
Medical History – Your medical history is the most important aspect of diagnosing S-RA. Be perfectly honest and concise about the onset of symptoms, the areas effected, how your feel physically upon awakening, during the day, and at bedtime. The documents that a rheumatologist give you to fill out prior to your first appointment can seem intrusive and exasperatingly long, but be sure to fill out the documents fully and honestly.
Physical Examination – If the rheumatologist you are seeing does not do a physical examination in which they touch your joints and ask you which ones are painful then see a different rheumatologist. A doctor cannot make a diagnosis without doing this type of physical examination. It is very important you be perfectly honest about which joints are irritated and how they feel because your treatment will be based upon these findings. If you over-exaggerate your symptoms because you a desperate to be believed you can come across as insincere causing your physician to doubt your disease claim and considering you to be a “drug seeker”. If you come off stoic and minimize the symptoms you are having then your doctor may miss diagnosing the stage your disease is in and not be aggressive enough with the medical treatment plan.
It takes more than a few lab tests to arrive at the diagnosis of S-RA. If your doctor hasn’t ran some of these tests I mentioned, you may ask them about these exams. Don’t hesitate to ask your doctor explain what test result means or why they are or are not ordering certain tests. By no means have I included all the tests that can be done. Before starting in biological agent there are a slew of labs that need to be done to make sure that you are not compromised with tuberculosis, hepatitis, or other diseases that could be fatal while on these powerful medications. There are also routine lab tests that are done frequently like a CBC – Complete Blood Count, which is a basic measure of health.
Educate yourself. You will find that the ignorance among general health care workers such as nursing staff and general practitioners can be profound. In many cases RA patients end up educating their health care teams about RA. Also know that you are not alone. The Rheumatoid Patient Foundation has published a white paper with their findings after polling RA patients which can give you some leverage in educating health care providers, family and friends. http://rheum4us.org/wp-content/uploads/2013/04/Unmasking-Rheumatoid-Disease-The-Patient-Experience-of-Rheumatoid-Arthritis-White-Paper.pdf
I would urge anyone who has joint pain that had a sudden onset and has persisted regardless of your rheumatoid factor and ANA lab work to seek a second opinion. You may be in the 20-30% of patients that have S-RA.