Features January 2006 Issue

Could It Be RA?

Those pains in your joints may be more than cartilage breakdown.

In determining which type of arthritis you may have, rheumatologists are required to be part detective—sifting through various signs and symptoms of disease, reviewing clues from X-rays and blood tests, and coming up with the most likely diagnosis.

“There still is no single symptom or test that can tell us definitively whether you have rheumatoid arthritis (RA), osteoarthritis (OA), or some other type,” says Abby Abelson, M.D., a rheumatologist at The Cleveland Clinic. “Instead, we need to consider the various facts we gather from your medical history, physical exam, and diagnostic tests before offering a diagnosis.”

Though the decision is based on the totality of evidence, there are clues that emerge relatively early that begin to point the diagnostic finger more in the direction of RA than OA. An awareness of such early clues for RA is becoming increasingly important, as doctors try to diagnose this disease earlier and earlier so that therapy can begin and the course of the disease can be slowed or halted before joint damage becomes advanced.  

Following are some of those early suggestive signs that can tip the diagnostic scales more in favor RA than OA, as well as a summary of recommended early-stage treatments.

Location, location
Though both RA and OA cause joint pain, they often differ in which joints are first affected and in what pattern.

When your hands are affected, by either RA or OA, your doctor will look to the pattern of finger involvement to help distinguish the two. RA occurs more often in the joints at the base of your fingers (the MCP or metacarpo-phalangeal joints) while OA is more common in the knuckles at the end and middle of your fingers (the DIP or distal interphalangeal joints, and the PIP or proximal interphalangeal joints). This difference is so marked that your doctor may perform a “squeeze test” on your hands, applying gentle pressure across the joints to evaluate for swelling and tenderness. For RA, the diagnosis requires involvement of the hand and/or wrist joints. For OA, the hand or wrist may or may not be involved.

Since osteoarthritis is a degenerative disease, marked by gradual thinning of joint cartilage, it frequently occurs in the large weight-bearing joints of your hips, knees, and spine. Conversely, rheumatoid arthritis, which is an inflammatory disease of the joint lining, usually occurs first in the smaller joints of your hand, wrist, and fingers. OA also is often a more one-sided disease than RA, affecting one hip or knee but not the other, while RA is more symmetrical in its impact, affecting both of your hands or wrists equally.

Morning stiffness
Another hallmark of arthritis, both RA and OA, is morning stiffness. For those with OA, the temporary stiffness in back, hips, and other joints usually subsides within a half hour or so. For those with RA, the stiffness may last much longer and sometimes requires several hours, if not all morning, to finally clear.

“People with RA who sit in one place for too long—more than an hour—are also more likely to become stiff and have a hard time getting going again,” says Dr. Abelson.

Exercise and rest
RA can often be distinguished from OA on the basis of how joint pain responds to activity and to rest. With OA’s effect on weight-bearing joints, the pain tends to get gradually worse if you’re on your feet all day, but then eases at night with rest. On the other hand, those with RA often find their joint pain and stiffness eases when they stand up and move about, but that the pain is not relieved by bed rest and may even keep them up at night. OA and RA may, in fact, co-exist; joints affected by RA may develop OA because of the joint damage RA can cause.

Steady or episodic pain
Whether your joint pain is steady, or comes and goes, is another measure used to help distinguish between the two forms of arthritis. OA tends to be characterized by the slow, steady breakdown of joint cartilage, and results in continuous pain that gradually worsens over time. On the other hand, RA is a bit less predictable, and can be episodic or constant, alternating between painful flare-ups that last for days or weeks, and months of less pain or even remission.

X-ray evidence
Beyond relying on symptoms to help distinguish between RA and OA, a rheumatologist will also look at X-rays to confirm the diagnosis. “These two types of arthritis look quite different on film,” says Dr. Abelson. “With RA, you often see small erosions or destruction of the bone with osteopenia, while with OA you will see tiny irregular outgrowths or bone spurs [osteophytes].”

Since X-ray evidence for RA may not be apparent until you have the disease for six to 12 months or more, physicians are now looking at magnetic resonance imaging (MRI) to help with earlier detection. Small, office-based MRIs are increasingly used in doctors’ offices, but more information is needed to determine if they are effective, as well as cost-effective, for detecting  early disease.

It’s in the blood
Physicians rely on a variety of blood tests to gain evidence of possible RA disease and build the case for early treatment.

“Even without clear X-ray evidence, if we have enough suggestive evidence for RA based on blood tests and symptoms, we’ll begin early aggressive treatment,” says Dr. Abelson.

Such blood tests look for the presence of proteins that are indicators of inflammation. An antibody known as rheumatoid factor is present in approximately 80 percent of patients who have had symptoms for six or more months. A newer test searches for cyclic citrullinated peptide (CCP), which may be present when rheumatoid factor is not. A sedimentation rate, which measures how quickly red blood cells clump together and fall into a tube, is a sign of systemic inflammation.

Early treatment
“Early diagnosis and early therapy is the new strategy for dealing with RA, and such an approach is likely to include prompt treatment with a combination of drugs to ease pain and interfere with the underlying disease. This combination therapy is part of a broader treatment plan that includes stretching and exercise to maintain or restore joint range of motion.

Combination therapy usually consists of a fast-acting nonsteroidal anti-inflammatory drug (NSAID) or corticosteroid for quick pain relief, in addition to a slower-acting disease modifying anti-rheumatic drug (DMARD) that requires several weeks or months to take effect. (Because of long-term side effects, many physicians try not to add corticosteroids or limit their use to the lowest doses possible to treat the inflammation.) Should these latter meds be of little help, there is a growing number of more potent medications, known as biological response modifiers, that can be used.

Biologics are genetically engineered to interfere with specific components of the immune response that contribute to inflammation and disease progression. Three of the newest and most widely available drugs in this category —etanercept (Enbrel), infliximab (Remicade) and adalimumab (Humira)—work by blocking the action of tumor necrosis factor (TNF alpha), a key component in joint inflammation. Anakinra is an antibody agent that protects against the cytokine interleukin-1 (IL-1), an inflammatory mediator that is produced in areas of inflammation, but it is less effective than TNF blockers and is therefore used less often.

Though recent studies have shown that the combined use of methotrexate and one of the biologics usually works better than single-drug therapy in early treatment, what works best for you may be something different. Individual response varies widely, so it is essential that you work with your rheumatologist in choosing and customizing your treatment.