Rheumatoid Factor (RF) Test: Understanding the Blood Test

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What is one way that RF testing can provide doctors with information about RA?

By predicting the exact age of onset

By determining the severity of the disease (correct)

By identifying the exact joints affected

By detecting the presence of rheumatoid nodules

What are the types of samples that can be used for RF testing?

Only clotted blood

Either serum or plasma (correct)

Only plasma

Only whole blood

What is the recommended storage temperature for deep frozen samples?

–25 C or below (correct)

–10 C to –15 C

–20 C to –25 C

–15 C to –20 C

What should be avoided when handling frozen samples?

Repeating thawing and freezing Signup and view all the answers

What is the purpose of centrifugation in preparing serum samples?

To remove particles and traces of fibrin Signup and view all the answers

What is the recommended time frame for using deep frozen samples?

Within 3 months Signup and view all the answers

What is the primary purpose of the Rheumatoid Factor (RF) test?

To diagnose rheumatoid arthritis Signup and view all the answers

What is the normal function of rheumatoid factor in the immune system?

To form a complex that the immune system can remove Signup and view all the answers

What is the result of a positive RF test in healthy people?

No significance, as it is a normal occurrence Signup and view all the answers

What is the relationship between RF and autoantibodies?

RF is a type of autoantibody Signup and view all the answers

What is a possible outcome of a positive RF test in addition to RA?

Sjögren's syndrome Signup and view all the answers

What percentage of healthy people can have a positive RF test?

4% Signup and view all the answers

What is the initial step in the qualitative determination on the test plate?

Bring the patient specimens and reagents to room temperature Signup and view all the answers

What is the approximate volume of the patient specimen applied to the test plate?

40 μl Signup and view all the answers

What is the purpose of agitating the test plate with a rotating action?

To mix the patient specimen with the latex particles Signup and view all the answers

What is the indication of distinct agglutination in the qualitative RF test?

The presence of rheumatoid factors at a concentration of 20 I.U./ml Signup and view all the answers

What is the purpose of preparing serial dilutions of the patient specimen in the semi-quantitative test?

To determine the concentration of rheumatoid factors Signup and view all the answers

What is the sensitivity of the semi-quantitative tube test?

Approximately 1 I.U./ml Signup and view all the answers

What is the purpose of coating latex particles with human gamma-globulin (IgG)?

To agglutinate when mixed with samples containing rheumatoid factors Signup and view all the answers

What type of immune complexes are formed in serum and joint fluid by rheumatoid factors?

Both self-association and reaction with native IgG Signup and view all the answers

In which tissues are complex deposition most common?

Tissues with restricted blood flow Signup and view all the answers

What is the significance of a seronegative rheumatoid arthritis?

It has a more favourable prognosis than seropositive Signup and view all the answers

What does an elevated RF titer often indicate?

A severe course and generalized pathological process Signup and view all the answers

What does the term 'seronegative RF' mean?

Rheumatoid factors are detectable neither in the latex agglutination nor in the Waaler-Rose test Signup and view all the answers