Welcome to the Positive Rheumatoid Factor (RF) Guide.

This decision Guide is designed for persons with a positive rheumatoid factor (RF) who would like to find out more about this test and what the result may mean.

The goal of this guide is to provide information while awaiting evaluation with your doctor, or for additional information after you have seen him or her. Please keep in mind that this guide is not intended to replace a face-to-face evaluation with your doctor. The diagnoses provided are among the most common that could explain your symptoms, but the list is not exhaustive and there are many other possibilities. In addition, more than one condition may be present at the same time.

The first thing to say is this: don't panic! The test is not so accurate that its result clearly means anything at all! Depending on your symptoms and the reason the test was ordered, the importance (or lack of importance) of your test result can usually be determined.

Would you like more information about the RF test in general, or would you rather proceed directly to what your RF may mean?

I'd first rather get more general information about RF.

I'd like more specific information about my RF.

The RF is an antibody detectable in the blood in about 70 percent of persons with rheumatoid arthritis but can often be found in other people as well. In fact, healthy people with no arthritis and no medical problems at all make tiny amounts of this antibody. In 90-95 percent of young, healthy persons, the amount of RF present in the blood is so low that it is considered absent from the blood and the test is considered negative (the "normal" result).

The number of healthy people having a positive RF rises somewhat with age, although sicker elderly people tend to have a positive RF more often than the healthy elderly. Also, when the RF is positive without disease present, it is usually only slightly positive, while higher levels are more likely to indicate "true" disease of one sort or another. See below for conditions other than rheumatoid arthritis associated with a positive RF.

Other conditions associated with arthritis may result in a positive rheumatoid factor: Sjogren's syndrome and systemic lupus erythematosus are good examples, but these conditions usually cause other symptoms and blood test abnormalities that provide clues to the diagnosis.

Certain infections, including endocarditis, viral infections, and others may trigger RF production by the body's immune system. Once the infection passes, repeat RF testing usually reveals negative results. Hepatitis C, a viral infection of the liver, is one of the more common ones, especially when a protein called "cryoglobulin" is present. This infection can be chronic (long-standing) so the RF may remain positive.

Three other situationsdeserve mention:

• People who tend to make one "autoantibody" (an antibody created against a part of one's own organs or tissues) may make others; so if you have an "autoimmune" condition, such as certain thyroid diseases or even type 1 diabetes, you may be more likely to make RF even without an associated disease.

• People with a family history of rheumatoid arthritis (or other RF-associated disorder) are more likely to have relatives with a positive RF, even if no disease is present.

• People "destined" to develop rheumatoid arthritis may have a positive RF detected years before they develop symptoms or signs of the disease. However, of all people with a positive RF and no joint symptoms, the vast majority are thought to remain free of RF-associated disease over time.

Click below to continue with the guide:

I'd like more specific information about my RF.

Okay. You'll be asked a series of questions about symptoms that are common in conditions in which the rheumatoid factor is present.

First of all: do you have joint pain?

Yes, I have joint pain.

No, I have no joint pain.

Excellent. That alone makes rheumatoid arthritis quite unlikely.

Do you have any of the following risk factors, symptoms, or conditions:

• hepatitis B

• hepatitis C

• other liver disease

• intravenous drug or cocaine use at any time in the past

• sexual contact with someone who has hepatitis or HIV

• a blood transfusion in the past?

Yes, I have one or more of those.

No, I have none of those.

Good, just a few more questions.

Have you had a heart murmur or abnormal heart valve or fever after recent dental work?

Yes, I have one or more of those.

No, I have none of those.

Good.

We're almost done.

Do have any of the following:

• chronic rash on your face, scalp or extremities

• mouth sores (similar to "canker sores" but many and frequent

• sensitivity to the sun (with fever or rash after brief periods of sun exposure)

• pleurisy (chest pain with breathing or fluid around the lining of the lung on a chest x-ray)

• seizures (or epilepsy)

• protein or blood in the urine or other kidney disease

• low blood counts

• another positive antibody, called the antinuclear antibody (ANA)

• dry eyes and/or dry mouth

• color changes in your fingers and/or toes caused by cold (called Raynaud's)

• tight, shiny skin over your fingers

• difficulty arising from a chair or combing or brushing hair due to muscle weakness?

Yes, I have one or more of those.

No, I have none of those either.

Excellent. There's a good chance that your positive RF is a false-positive, meaning that it is abnormal but of no clear significance. That does happen, perhaps more often than many people (and many doctors) realize. It's simply that the test is far from perfect in identifying those with diseases such as rheumatoid arthritis and separating them out from those who are healthy.

From your answers, there are a number of possible explanations for your symptoms and a positive RF, even without prominent joint pain.

For example:

• unusual dryness of the eyes and mouth could indicate the presence of Sjogren's syndrome. On the other hand, some people simply don't make enough tears and/or saliva, and they do not have this disease

• joint pain, rashes and/or mouth sores, and almost any of these other symptoms are seen in people with lupus

• people with Raynaud's and tight shiny skin may have scleroderma.

Because your symptoms suggest the possibility of one of these rheumatic conditions, it is important that you see your doctor promptly for evaluation.

Endocarditis is one possible explanation for your positive rheumatoid factor, although there are still other possibilities.

Endocarditis is a serious condition. It is a bacterial infection of a heart valve. While fairly rare, it tends to occur in people who have an abnormal heart valve to begin with, especially after having bacteria in the blood (as may occur during visits to the dentist for routine cleaning or other care). It can also occur in people who use intravenous drugs.

Because endocarditis is a serious infection that requires prompt detection and treatment, it is important that you contact your doctor right away for evaluation.

You could have hepatitis or other infection that may cause the rheumatoid factor to be positive, even without rheumatoid arthritis.

Contact your doctor for prompt evaluation!

Sorry to hear that. Now, to sort out whether your joint pain has anything to do with the rheumatoid factor:

Do you have four or more joints that are painful?

Yes, I have four or more painful joints.

No, I have three or fewer painful joints.

Okay. And are your joints swollen?

Yes, I have swelling in my painful joints.

Nope, no swelling.

That's good news! It means that true arthritis is less likely (although swelling is rarely seen in certain joints, such as the shoulder, hip or spinal joints--you could still have arthritis in them without seeing any swelling).

Your symptoms could be an indication of fibromyalgia, a viral infection, thyroid disease, an elevated calcium level in the blood (called hypercalcemia), or some other condition that will resolve on its own. None of these are strongly associated with a positive RF so your result could be a "false-positive" (abnormal even in the absence of an abnormal condition).

Rheumatoid arthritis is less likely because there is usually swelling in joints that are easy to see (for example in the hands and wrists) and there are multiple joints involved, typically six or more.

Unless your symptoms resolve soon, contact your doctor for evaluation. Early diagnosis and treatment are important, not only to get you feeling better but to prevent complications of the condition causing your joint symptoms and positive RF.

Okay.

And have you had painful joints for at least six weeks?

Yes, I've had joint pain for at least six weeks.

No, I've had joint pain for less than six weeks.

It's possible that you have rheumatoid arthritis (RA), but when symptoms are present for less than six weeks, it is difficult to be sure, even with a positive RF result. That's because the joint symptoms and positive rheumatoid factor could be due to a virus that the body will fight off in short order--and then, all of your symptoms should go away. It's also possible you have a condition related to RA, such as lupus or Sjogren's syndrome.

Okay so you have three or fewer painful joints for at least six weeks, with swelling. There are a number of possible explanations for your symptoms and a positive RF.

With these symptoms and a positive RF, rheumatoid arthritis (RA) is one possibility, especially if your joint symptoms are worse in the morning for at least an hour. However, in RA, there are usually many more joints involved, often six or more.

And there are other considerations, such as:

• scleroderma - especially if you have color changes in your fingers and/or toes caused by cold, or tight, shiny skin over your fingers.

• Sjogren's syndrome - especially if you have dry eyes and dry mouth

• systemic lupus erythematosus (SLE) (also known as lupus) - especially if you have had a rash on your face, sensitivity to the sun, pleurisy (chest pain with breathing), seizures, or certain blood test abnormalities. Another antibody, called the antinuclear antibody (ANA) is nearly always positive in people with SLE.

• infection - although somewhat unusual to affect this many joints for a prolonged period of time, certain infections, especially viruses such as hepatitis C or parvovirus occasionally cause arthritis that goes on longer than six weeks.

 If you have had fevers of more than 100.8F, it becomes particularly important to see your doctor to have an evaluation for an infectious cause of fever, arthritis and a positive RF.

Sorry to hear that.

Do you have swelling in your painful joints?

Yes, I have swelling in my painful joints.

Nope, no swelling.

When there is prominent joint pain in multiple joints but no swelling, several possibilities come to mind:

• There is arthritis (joint inflammation) but it cannot be seen, at least not yet. Examples include early rheumatoid arthritis or lupus, although there are nearly always other indications by symptoms, physical examination and blood tests. In general, rheumatoid arthritis cannot be diagnosed without joint swelling.

• The joints involved are deep (such as hips and shoulders), so swelling can rarely be seen even with marked inflammation. An example is polymyalgia rheumatica (PMR) which causes sudden onset of pain and morning stiffness in the shoulders and hips among persons ages 55 and older; the RF is usually absent in this condition, though. The condition causes pain but is not a form of arthritis.

• Fibromyalgia, thyroid disease, and high blood calcium (hypercalcemia) are good examples of conditions that can cause terrible bone, joint, and/or muscle pain and yet no arthritis is present. These conditions are not associated with a positive RF so the RF result would be irrelevant to the symptoms--that is, it would be considered a false-positive.

That's terrible! When there is swelling in addition to pain, arthritis is usually present.

Have you had painful joints for at least six weeks?

Yes, my joints have been bad for at least six weeks.

No, my joints have been bothering me for less than six weeks.

Okay. The next question is to find out more about a possible infection.

Have you had a fever (temperature of more than 100.8F)?

Yes, I've had an elevated temperature of 100.8F or higher.

No fever.

Okay.

And, have you had a fever (temperature of more than 100.8F)?

Yes, I've had an elevated temperature of 100.8F or higher.

No fever.

Good.

And have you noticed or been told of any of the following:

• color changes in your fingers and/or toes caused by cold (called Raynaud's)

• tight, shiny skin over your fingers

• dry eyes and dry mouth

• chronic rash on your face, scalp or extremities

• mouth sores (similar to "canker sores" but many and recurrent)

• sensitivity to the sun (with fever or rash after brief periods of sun exposure)

• pleurisy (chest pain with breathing or fluid around the lining of the lung on a chest x-ray)

• seizures (or epilepsy)

• protein or blood in the urine or other kidney disease

• low blood counts

• another positive antibody, called the antinuclear antibody (ANA)?

Yes, I have had one or more of these.

No, I have the joint trouble, but none of these other problems.

Based on your symptoms, you could have rheumatoid arthritis (RA). The diagnosis is most likely when symptoms have been present for at least six weeks and no other symptoms (such as high fever or rash) or other conditions are present that could explain your joint trouble in some other way. Early diagnosis and treatment can make a big difference in how well you do, so it is important to contact your doctor for prompt evaluation.

Keep in mind that even if you do have RA, there are mild forms that can be treated with mild medicines, and while you may read that RA can be "crippling" that is rare in the modern era when so many medications are available to keep the arthritis controlled. And even when joints are damaged beyond the ability of the medicines to help, surgery can usually be offered to maintain function and control pain.

It is also possible you do not have rheumatoid arthritis and that even though the joints seem swollen to you, your doctors may find no swelling and attribute your symptoms to something else, such as fibromyalgia or one of the other rheumatic diseases. Because the diagnosis cannot be made without an examination, go see your doctor soon!

Okay. There are a number of possible explanations for your symptoms and a positive RF.

The positive RF along with the symptoms you mention could be indications of a rheumatologic condition such as rheumatoid arthritis (RA) or a closely related condition.

For example:

• dry eyes and/or dry mouth with a positive RF may be evidence of Sjogren's syndrome (some people with rheumatoid arthritis have similar symptoms, so the distinction may be difficult)

• joint pain, rashes and/or mouth sores, and almost any of the other symptoms mentioned are typical in people with lupus

• tight, shiny skin and Raynaud's may indicate scleroderma.

• Because you have had rather prolonged joint symptoms along with other problems that could indicate rheumatoid arthritis, lupus or another rheumatic disease, it is important that you contact your doctor for prompt evaluation. These conditions can be serious and early diagnosis and treatment can make a big difference.

Your symptoms could be due to an infection. Most infections do not go on for six or more weeks, but occasionally it happens.

Examples include

• a bloodstream infection (called subacute bacterial endocarditis)

• virus infections (such as those in the "mono" family)

• chronic forms of hepatitis.

On the other hand, some arthritic disease unrelated to infection can cause fever. Lupus is a good example; rheumatoid arthritis is possible whenever the RF is positive and there is arthritis, but fever this high is unusual. Of course, the fever could be unrelated to the joint trouble.  People with arthritis (including rheumatoid arthritis) can get a fever from a cold or the flu or another infection that is coincidental.

Contact your doctor for evaluation to be sure you do not have an infection causing your joint symptoms and positive RF.

You have completed the positive RF decision guide. We hope the information here was helpful; if your situation changes or you would like additional information, please return here later.

Remember: just because a person's rheumatoid factor is positive does not mean they have rheumatoid arthritis. Doctors cannot diagnose rheumatoid arthritis (or most any other type of arthritis) from a blood test!