Rheumatoid Arthritis (RA)

Rheumatoid arthritis (RA) is a chronic autoimmune disease that primarily affects the joints, causing inflammation, pain, stiffness, and eventually joint deformities.

1. ACR 1987 Criteria for Diagnosing RA:

The ACR (American College of Rheumatology) 1987 criteria is a set of standards used to diagnose RA. A patient is diagnosed with RA if they have at least 4 of the following 7 criteria:

• Morning stiffness lasting > 1 hour: Morning stiffness is a hallmark sign of RA, typically lasting longer than 1 hour.

• Arthritis of 3/14 joint areas: Arthritis in at least 3 of the following 14 areas: metacarpophalangeal (MCP) joints, proximal interphalangeal (PIP) joints, wrists, elbows, knees, ankles, metatarsophalangeal (MTP) joints (bilaterally).

• Arthritis of 1/3 joint areas: Arthritis in at least 1 of 3 areas: MCP joints, PIP joints, wrists.

• Symmetrical arthritis: Arthritis occurring on both sides of the body, such as both hands or both knees.

• Rheumatoid nodules: Rheumatoid nodules are small, firm, painless bumps that appear under the skin, often found around the elbows, fingers, and heels.

• Positive RF (Rheumatoid Factor): Rheumatoid factor (RF) is an autoantibody found in the blood of approximately 70-80% of RA patients.

• Typical radiographic changes: Typical radiographic changes of RA include erosions, joint space narrowing, joint fusion, and joint deformities in the wrists and hands.

A definitive RA diagnosis is made when a patient has 4 or more criteria and the duration of symptoms is at least 6 weeks.

Note:

• RA diagnosis based on the ACR 1987 criteria should be done by a rheumatologist, considering clinical symptoms, laboratory tests, and imaging.

• Some RA patients may not fulfill all the ACR 1987 criteria, especially in the early stages of the disease.

• Accurate RA diagnosis is essential for timely and effective treatment.

2. Prevalence of RA in Vietnam:

The prevalence of RA in Vietnam is reported to be 0.28%.

3. Joint Deformities in RA:

RA can cause various types of joint deformities, including:

• Swan-neck deformity: The finger is abnormally bent at the PIP joint, while the DIP joint is straightened.

• Boutonnière deformity: The finger is bent at the DIP joint, while the PIP joint is straightened.

• Ulnar drift: The fingers drift towards the little finger due to weakening of the tendons and ligaments.

• Flatfoot deformity: The foot flattens due to damage and deformity of the joints in the foot.

Note:

• Joint deformities are one of the serious complications of RA, potentially causing limited mobility and impacting the patient’s quality of life.

• Early RA treatment can help minimize the risk of joint deformities.

4. Common Extra-Articular Manifestations:

Apart from joint symptoms, RA can also cause various extra-articular manifestations, including:

• Normocytic or microcytic hypochromic anemia: RA can lead to anemia due to a lack of red blood cells caused by the autoimmune disease.

• Pericarditis: Pericarditis is a rare complication of RA.

• Interstitial lung disease: Interstitial lung disease is a rare complication of RA, which can cause shortness of breath and cough.

• Sjogren’s syndrome: Sjogren’s syndrome is a condition that causes dry eyes and dry mouth, and can occur alongside RA.

• Vasculitis: Vasculitis is inflammation of blood vessels, and can also occur with RA.

Note:

• Extra-articular manifestations of RA may be atypical and difficult to diagnose.

• Treatment of extra-articular manifestations is crucial for improving the patient’s quality of life.

5. Specific Radiographic Findings of RA according to ACR 1987 Criteria:

Typical radiographic findings of RA include:

• Erosions: Erosions are small cavities on bone, created due to bone destruction.

• Joint space narrowing: The joint space is the gap between two bone ends, filled with cartilage. In RA, cartilage is destroyed, and the joint space narrows.

• Joint fusion: Joint fusion is the condition where the bone ends stick together, limiting joint movement.

• Joint deformities: Joint deformities are alterations in the shape of the joint due to cartilage destruction and bone deformities.

Note:

• Radiographic changes of RA are often not present in the early stages of the disease.

• X-ray imaging can help determine the severity of joint damage and monitor the disease progression.

Conclusion:

RA is a chronic disease that can severely affect the health and quality of life of patients. Timely diagnosis and treatment of RA are crucial for minimizing complications and improving the patient’s condition.