The diagnosis of lupus is made based on your findings, your doctor’s examination and blood results. Since many findings seen in lupus may also be present in other diseases, your doctor may need to examine whether other diseases are present.
Many different blood tests are used to reach the diagnosis:
Anti-Nuclear Antibody (ANA):
The ANA test is positive in 95% of individuals with lupus. However, since some healthy individuals may also be positive for ANA at low titers, it does not provide a definitive diagnosis of the disease. In addition, ANA (+) can be found in a group of diseases called “Connective Tissue Disease”, including Lupus, and progressing with different findings.
Anti-Double Strand DNA (Anti-dsDNA) Test:
It is found positive in 70% of individuals with lupus. A positive test for this test strengthens the possibility that they have lupus, because individuals who do not have lupus usually do not have a positive test. Elevation of this test is often associated with more active disease and sometimes the intensity of treatment is adjusted accordingly. For this reason, anti-dsDNA may need to be checked from time to time in regular follow-ups.
Anti-Ro Antibody Test:
If your test is positive, it is expected that the skin findings called rash and a condition called Sjögren’s Syndrome, which is characterized by dry eyes and mouth, are expected to accompany the disease. During pregnancy, these antibodies can pass from mother to baby, and in this respect, the pregnancy process should be followed more closely.
Antiphospholipid Antibody Test:
A positive test for this test is associated with intravascular clot formation and an increased risk of miscarriage during pregnancy.
Complement Levels (C3 and C4):
Complements are a group of proteins found in the blood that protect us from microbial infections. When lupus flares up, complement levels in the blood drop.
Erythrocyte Sedimentation Level (ESR): It is a test that evaluates the inflammatory process by evaluating the sedimentation rate of blood cells in the test tube. ESR is usually high in lupus.
Kidney and Liver Function Tests:
It is done with a group of blood and urine tests. In this way, it is ensured that the problems that may arise due to the disease or the drugs used in the treatment are determined and the treatment is arranged accordingly.
Blood Count:
This test evaluates cells in the blood. These cells are red blood cells, white blood cells and platelets. All these cells are made in the bone marrow, and by means of this test, it can be determined whether the bone marrow is affected due to the disease or drug effect.
Other Tests:
Some other tests may be requested depending on the organ that is thought to be affected. Investigations such as x-ray, ultrasonography, computed tomography and magnetic resonance can be used to evaluate the disease from time to time.
The presence of kidney damage can be evaluated with a urine test. It may be possible to detect the kidneys to be affected by the disease with increased protein excretion or the presence of blood cells in the urine and start treatment without serious kidney damage.
Sometimes, it may be necessary to take a sample from the tissue or organ that is thought to be affected by biopsy and evaluate it, and the treatment may need to be adjusted accordingly.
