Lupus is a systemic disease meaning it affects more than one body system. Physicians use blood tests, body symptoms and patient’s complaints to diagnose the disease. Lupus blood test results will show the presence of auto-antibodies that attack normal cells, reacting as if they are infectious cells. It can cause inflammation and even destroy the good cells.
The John Hopkins Lupus Center indicates the following blood tests in the diagnosing of lupus.
The anti-nuclear antibody (ANA) test is found in 98 percent of lupus cases, making it the most common test. A large segment of society has a positive ANA but not the disease. A positive ANA test can distinguish what type of lupus is present by the pattern it displays. Systemic lupus will show a diffuse, shaggy or speckled pattern. A positive scleroderma test will show a nucleolar pattern.
A positive ANA is not enough to diagnose lupus. An ANA panel includes an anti-double-stranded DNA, and four other studies are included. A positive anti-double stranded DNA (anti-DNsA) usually indicates serious lupus such as nephritis lupus. The lupus has invaded the kidneys at this point and can interfere with functioning.
The anti-Smith antibody can assist physicians in determining if systemic lupus is present. Twenty percent of lupus cases show the anti-Smith antibody. It can distinguish between other rheumatic diseases where it is not present.
Anti-U1RNP antibodies are found in 25 percent of lupus patients. The antibody is also found in other auto-immune disease such as rheumatoid arthritis, Sjögren’s syndrome, and polymyositis. The examination of blood serum is part of the comprehensive study of concluding lupus blood test results.
Anti-RO and anti-LA
Two other antibody tests include anti-RO and the anti-LA. Thirty to forty percent of systemic lupus patients have the antibodies, as well as people with Sjögren’s syndrome. A specific genetic deficiency caused from the antibodies that are present at birth are passed on from the mother. It can cause congenital heart block. Testing for the antibodies should take place in women that have lupus before becoming pregnant.
Serum Blood Complement
The serum blood complement test shows the amount of proteins used when inflammation is present in the body. This test is part of the overall screening in determining the lupus blood test results.
According to the Mayo Clinic another antibody test used to determine if lupus is present is the anti-phospholipid antibodies. A test to diagnose syphilis is used because a false-positive result can reveal systemic lupus. The presence of the antibody is also associated with strokes, blood clots and miscarriages.
There are eleven criteria for diagnosing lupus. A person must exhibit at least four of the following eleven symptoms to obtain a positive diagnosis.
Butterfly rash across the bridge of the nose and cheeks
Rash that is related to sun exposure
Joint pain and swelling in more than two joints
Mouth sores that are painless
Neurological disorder such as psychosis or seizures
Low blood counts
Positive blood counts indicating lupus including anti-DNA, anti-phospholipid antibody and anti-Sm
Lupus is a systemic inflammatory disease that can affect the skin, bones, organs and joints. Four types of lupus; systemic, discoid, drug induced and neonatal make it difficult to pinpoint the disease with one test. Diagnosing the disease must include positive lupus blood test results as well as several other factors. The first step is getting diagnosed. A physician that specializes in rheumatology can direct the testing for the disease and treatment.
John Hopkins Lupus Center: Lupus Blood Tests
Mayo Clinic: Lupus Tests and Diagnosis