Labs for Arthralgias

Question 1

What does the Antinuclear Antibody (ANA) show?

Answer 1

There is inflammation in the blood

Question 2

What can cause a false positive with ANA test?

Answer 2

Cancer, chemo, some meds (INH, procainamide, hydralazine)

Question 3

What does RA factor help diagnose?

Answer 3

Rheumatoid Arthritis

Question 4

What can cause the RA test to be a false positive?

Answer 4

Chronic infection or chronic inflammation

Question 5

When will the erythrocyte sedimentation rate (ESR or sed rate) be elevated?

Answer 5

Increased with anemia, inflammation, infection, obesity, cancer, psychosocial stress

Question 6

If the ESR is elevated but the RA and ANA are negative what should you suspect?

Answer 6

Cancer

Question 7

If ESR is >100 mm/hr what should be expected?

Answer 7

Infection, cancer, inflammation (temporal arteritis, polymyalgia rheumatica, nephrotic syndrome)

Question 8

hs-CRP >10 mg/L should be expected with what problems?

Answer 8

Rheumatic causes, infection or inflammation (may be high with ACS but not stable angina) Recheck another level in 2 weeks