Diagnosing Lupus | Blood, ANA, ESR & More Tests

Lupus - Diagnosis

Diagnosing lupus is difficult because the disease varies considerably from person to person and the signs and symptoms come and go unpredictably and overlap with many other diseases. Therefore, doctors may not initially consider lupus until the signs and symptoms become more definite.

Even then, diagnosis can often be challenging and a number of laboratory tests are necessary to confirm the diagnosis.

These tests include the following:

Full blood count: This test measures the levels of haemoglobin, number of red blood cells, white blood cells and platelets. Results may indicate the presence of anaemia, or low white blood cell or platelet count. An extremely low platelet count can result in spontaneous bleeding in the skin (bruises), in the stomach or even in the brain
Erythrocyte Sedimentation Rate (ESR): the ESR is raised in many disorders including lupus. It is sometimes a good measure of disorder activity and as your disorder improves your ESR may drop
Urine examination: An examination of your urine may show an increase in red blood cells or protein level. This can occur if lupus has affected your kidneys. Kidney function tests - Blood tests can assess how well your kidneys are functioning
Antinuclear antibody (ANA): A positive test for these antibodies indicates a stimulated immune system which is common in lupus and other autoimmune diseases. However, a positive ANA test is not always indicative of lupus since certain infections or drugs can lead to a positive test. In fact, a small proportion of normal individuals can have a slightly raised ANA antibody test. Therefore, this test needs to be interpreted in conjunction with a proper history and physical examination
Anti-dsDNA test: This test is often done together with the ANA test. Patients with lupus and kidney involvement often have a raised anti-dsDNA test