Systemic lupus erythematosus(SLE), otherwise known as lupus.
To confirm the diagnosis, all other possible causes of your symptoms must be excluded.
Autoantibodies are immune proteins that mistakenly attack normal cells thinking they are pathogens.
Illustration by Joshua Seong for Verywell Health
There is no single autoantibody associated with lupussome of the following occur with other autoimmune diseases.
However, their presence can help confirm the diagnosis.
All told, around 97% of people with lupus will have a positive ANA test result.
Get our printable guide for your next healthcare provider’s appointment to help you ask the right questions.
A negative ANA test result means that lupus is unlikely.
Certain titer values and patterns are more suggestive of lupus than others.
Blood Tests
There are many blood tests involved in the diagnosis of lupus.
They are used mainly to diagnose features of the disease rather than the disease itself.
They may also be used to exclude other causes.
C-reactive protein (CRP) is another marker of general inflammation.
But unlike ESR, it doesn’t typically rise with lupus flares.
Urinalysis
Urinalysiscan detect abnormal substances in your urine.
When the kidneys are damaged by lupus, excess protein can leak into your urine.
There may also be bleeding that is invisible (microscopic) or visible (gross).
A high number of red blood cells or protein in your urine may be a sign of lupus nephritis.
These proteins also play a role in spurring inflammation in the body.
In some forms of lupus, complement proteins are depleted by the autoimmune response.
A decrease in the complement level is often seen with lupus nephritis.
The tissue can be tested to check for signs of inflammation or tissue death (necrosis).
Other tests can show if you have autoantibodies related to lupus.
All other possible causes must also be excluded.
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