Question

Consider the following statements regarding rheumatoid arthritis: 1. The synovial fluid is turbid. 2. Synovial fluid mucin clot test is good. 3. Synovial fluid complement level is decreased. 4. Synovial membrane histology characteristically shows severe synovial lining proliferation and presence of lymphoid follicles. Which of these statements are correct?

• A. 1, 2 and 3
• B. 1, 3 and 4
• C. 1, 2 and 4
• D. 2, 3 and 4

Hint:

One of the four statements describes the mucin clot the wrong way round - check that one closely.

Answer 1

The Correct Option is B

Step 1: Understanding the Question:
The question asks which combination of statements about rheumatoid arthritis synovial fluid and synovium is correct.

Step 2: Key Concept or Approach:
Each statement has to be checked against the known features of RA synovial fluid, namely its appearance, mucin clot quality, complement level, and synovial histology.

Step 3: Working Through the Options:
Statement 1 is true: synovial fluid in RA is inflammatory and appears turbid or cloudy because of the high white cell count. Statement 2 is false: the mucin clot test reflects hyaluronic acid quality, and in inflammatory arthritides like RA, proteolytic enzymes degrade hyaluronate, giving a poor, friable mucin clot rather than a good one. Statement 3 is true: synovial fluid complement, such as C3, C4 and CH50, is characteristically low in RA because complement is consumed by immune complex activity within the joint, unlike in most other inflammatory arthritides where it stays normal or high. Statement 4 is true: RA synovium classically shows villous hypertrophy with proliferation of the synovial lining cells, dense lymphoid infiltrates that can organize into lymphoid follicles, and pannus formation.

Step 4: Conclusion:
Statements 1, 3 and 4 are correct while statement 2 is false, so 1, 3 and 4 is correct.