Lab Tests for Lupus
Blood Tests for Lupus continued...
Complete Blood Cell Count (CBC)
- What it is: CBC is a test to measure levels of different blood cells.
- Why the test is used: Abnormalities in blood cell counts, including white blood cells and red blood cells, may occur in people with lupus. This may be related to the lupus, lupus treatments, or infection. For example, leukopenia, a decrease in the number of WBCs, is found in about 50% of people with lupus. Thrombocytopenia, or a low platelet count, occurs in about 50% of people with lupus, as well. Doctors can use this test to monitor these potentially serious problems.
- Limitations of the test: Many other medical conditions can cause abnormalities in blood cell counts. So the test by itself is not specific to a lupus diagnosis.
- What it is: A chemistry panel is a test to assess kidney function and liver function. It also gives information on electrolytes, blood sugar, cholesterol, and triglyceride levels.
- Why the test is used: Abnormalities may indicate the development of complications from lupus. They could also result from treatments for such conditions as kidney disease, elevated blood sugar levels, elevated cholesterol levels, and liver disease.
Urine Tests for Lupus
Besides blood tests used to diagnose and monitor lupus, doctors use urine tests to diagnose and monitor the effects of lupus on the kidneys. These tests include the following:
- Measurement of Glomerular Filtration Rate and Proteinuria.This test measures how effective the kidneys are at filtering the blood to eliminate waste products. It is conducted on urine collected over a 24-hour period.
- Protein/Creatinine Ratio: This test is performed on a one-time urine sample. It measures for protein loss, which is an indicator of kidney function.
- Urinalysis: Urinalysis can be used in screening for kidney disease. The presence of protein, red blood cells, white blood cells, and cellular casts may all indicate kidney disease.