No fasting required.

While the role of RF is not well understood, it may not directly cause joint damage, but promote the body's inflammation reaction which in turn contributes to autoimmune joint destruction. 

 

This test detects and measures rheumatoid factor (RF), a type of “autoantibody”, in the blood. We all have antibodies (also known as immunoglobulins) in our blood, which are protective proteins which defend the body against infection, particularly from bacteria. However, “autoantibodies” may attack the patient’s own tissues mistakenly identifying them as “foreign”.