What is Rheumatoid Arthritis (RA)?

Rheumatoid Arthritis (RA) is traditionally considered a chronic, inflammatory autoimmune disorder that causes the immune system to attack the joints. It is a disabling and painful inflammatory condition, which can lead to substantial loss of mobility due to pain and joint destruction. RA is a systemic disease, often affecting extra-articular tissues through the body including the skin, blood vessels, heart, lungs, and muscles.

What are the symptoms?

• Morning stiffness of >1 hour most mornings
  
• Soft tissue swelling of joints/joint groups
  
• Subcutaneous nodules in specific places
  
• Rheumatoid factor at a level above the 95th percentile
  
• Radiological changes suggestive of joint erosion
  

Why test for Rheumatoid Arthritis?

When RA is being clinically suspected, immunological studies are required, such as rheumatoid factor (RF, a specific antibody). A negative RF does not rule out RA; rather, the arthritis is called sero-negative. During the first year of illness, rheumatoid factor is frequently negative. Eighty percent of patients eventually convert to sero-positive status. RF is also seen in other illnesses, like Sjögren’s syndrome, and in approximately 10% of the healthy population, therefore the test is not very specific.

As the pathology progresses the inflammatory activity leads to erosion and destruction of the joint surface, which impairs their range of movement and leads to deformity. The fingers are typically deviated towards the little finger and can assume unnatural shapes.

Methodology

The ASI RF Direct Slide Test is a slide agglutination assay for the qualitative and the semiquantitative determination of rheumatoid factor (RF) in human serum. No initial dilution of patient samples is required for this test. These materials are intended to be acquired, possessed and used only by health professionals.