Diagnostic Challenges

“The Great Imitator”

Lupus is known as “the great imitator”, because its symptoms mimic many other illnesses. Symptoms can also be unclear, can come and go, and can change.

— Lupus Foundation of America

Clinicians rely upon a series of 11 criteria to diagnose the disease.  According to the American College of Rheumatology (ACR) based classification for lupus, patients with 4 of the 11 criteria are diagnosed as lupus positive.  Classification is based on:

  • Symptoms
  • Medical history
  • Laboratory Tests

Laboratory Tests

Early diagnosis is critical in avoiding major organ damage

  • Laboratory tests are used to monitor some of the ACR criteria
    • Supplement clinical observations and judgment
  • —No currently available single test can give a definite “yes” or “no” answer
    • Test results that are indicative of lupus may be due to other illnesses or can even be seen in healthy people
    • A test result may be positive one time and negative another time
    • Different laboratories may produce different test results
  • Battery of tests that may be used in differential diagnoses include:
    • Routine blood test (e.g. CBC)
    • Antibody screening (e.g. ANA, anti-dsDNA)
    • Other blood tests(e.g. complement, CRP, coagulation times)
    • Urine analysis
    • Tissue biopsies