Lupus, also known as systemic lupus erythematosus (SLE), is a chronic autoimmune disease that can affect various parts of the body, including the skin, joints, kidneys, heart, and brain. It is important to diagnose lupus early in order to manage the condition effectively and prevent complications. In this article, we will discuss the different tests used to diagnose lupus in 2023.
1. Medical History and Physical Examination
The first step in diagnosing lupus is a thorough medical history and physical examination conducted by a healthcare professional. The doctor will ask about your symptoms, family history, and any possible triggers or exposures. They will also perform a physical examination to check for any signs of lupus, such as a butterfly-shaped rash on the face or swollen joints.
2. Blood Tests
Blood tests are an essential part of diagnosing lupus. The following blood tests may be conducted:
a. Antinuclear Antibody (ANA) Test
The ANA test is often the first test ordered to check for autoimmune disorders, including lupus. It detects the presence of antibodies that attack the nucleus of cells. A positive ANA test indicates a higher likelihood of lupus, but further tests are needed for a definitive diagnosis.
b. Complete Blood Count (CBC)
A CBC measures the levels of red and white blood cells and platelets in the blood. People with lupus may have low red blood cell counts (anemia), low white blood cell counts (leukopenia), or low platelet counts (thrombocytopenia).
c. Erythrocyte Sedimentation Rate (ESR) and C-Reactive Protein (CRP)
ESR and CRP tests measure the level of inflammation in the body. Elevated levels may indicate active lupus.
d. Kidney Function Tests
Lupus can affect the kidneys, so tests such as urine analysis and blood urea nitrogen (BUN) and creatinine tests may be conducted to assess kidney function.
3. Antibody Tests
In addition to the ANA test, several other antibody tests may be performed to aid in the diagnosis of lupus:
a. Anti-dsDNA Antibody Test
This test detects the presence of antibodies specific to double-stranded DNA. High levels of anti-dsDNA antibodies indicate a higher likelihood of lupus.
b. Anti-Smith (Sm) Antibody Test
The presence of anti-Smith antibodies is highly specific to lupus, and this test helps confirm the diagnosis.
c. Anti-Ro/SSA and Anti-La/SSB Antibody Tests
These tests detect the presence of antibodies that can be found in people with lupus and certain other autoimmune disorders.
In some cases, a biopsy may be necessary to confirm a lupus diagnosis. A small sample of tissue, such as skin or kidney tissue, is taken and examined under a microscope to look for characteristic changes associated with lupus.
Diagnosing lupus requires a combination of medical history, physical examination, and various laboratory tests. If you experience symptoms such as fatigue, joint pain, skin rashes, or unexplained fever, it is important to consult a healthcare professional who can perform the necessary tests to determine if lupus is the underlying cause.