Welcome to JA and thanks for asking
There is no single definitive test but usually if the complete blood counts,complement levels,ESR and CRP indicate possibility of Lupus then one should have an Anti-nuclear antibodies,Anti-double stranded DNA and Extractable nuclear antigens. The sensitivities of these antibodies are different but these are the usual tests. If diagnosed then urine should be screened for hematuria,proteinuria or cellular casts to rule out kidney involvement.
Feel free to ask if you have any more question
Please leave a POSITIVE (3 – 5 stars, preferably 5) rating by clicking on the stars above, until you do i am not compensated for my time. You can continue to ask follow-up questions even after the POSITIVE rating
yes these antibodies are required when suspecting lupus
Yes these are blood tests
Anti nuclear antibodies is not a specific test and can be positive in many other conditions
Anti-double stranded DNA and Anti-Smith (done as part of extractable nuclear antigens) is quite specific for lupus. There are other antibodies which have variable sensitivity and specificity for lupus done as extractable nuclear antigens
Anti nuclear antibodies can be positive in RA and Multiple Sclerosis
ESR is usually raised in lupus but it is non-specific test. Complement levels are usually low in active lupus and is used to monitor disease activity rather than diagnosing it.