Rheumatologists often use blood work as an important tool in diagnosing and monitoring various rheumatic conditions. They look for specific markers and indicators in the blood that can provide insights into the presence and severity of inflammation, autoimmune activity, and other factors related to the patient’s condition. Here are some of the key things that rheumatologists typically look for in blood work:
1. Erythrocyte Sedimentation Rate (ESR) or Sed Rate: As mentioned earlier, the ESR measures the rate at which red blood cells settle to the bottom of a tube over time. A higher sed rate indicates increased inflammation in the body, which can be a sign of various rheumatic conditions such as rheumatoid arthritis, systemic lupus erythematosus, or giant cell arteritis.
2. C-reactive protein (CRP): CRP is another marker of inflammation that can be measured in the blood. Elevated CRP levels often indicate acute or chronic inflammation in the body. This test is particularly useful in monitoring diseases like rheumatoid arthritis, vasculitis, or systemic lupus erythematosus, as well as assessing response to treatment.
3. Complete Blood Count (CBC): The CBC provides information about the number and types of blood cells in the body. Rheumatologists pay attention to the levels of white blood cells, red blood cells, and platelets. Abnormalities in these levels can indicate underlying conditions such as anemia, infection, or bone marrow disorders.
4. Rheumatoid Factor (RF) and Anti-cyclic Citrullinated Peptide (anti-CCP): These are antibodies that are often present in individuals with rheumatoid arthritis. Detecting the presence of RF and anti-CCP antibodies helps confirm the diagnosis of rheumatoid arthritis and can also help differentiate it from other types of arthritis.
5. Antinuclear Antibodies (ANA): ANA testing is used to detect the presence of specific antibodies that target the body’s own cells and tissues. Elevated ANA levels are commonly associated with autoimmune diseases such as systemic lupus erythematosus, Sjögren’s syndrome, or mixed connective tissue disease.
6. Uric Acid: Uric acid levels are measured to evaluate the risk of gout, a type of arthritis caused by the buildup of uric acid crystals in the joints. High levels of uric acid can indicate gout or an increased risk for developing it.
7. Other specific antibodies: Depending on the suspected condition, rheumatologists may order additional blood tests to detect specific antibodies associated with certain diseases. Examples include anti-dsDNA antibodies for lupus, anti-SSA and anti-SSB antibodies for Sjögren’s syndrome, or anti-citrullinated protein antibodies for rheumatoid arthritis.
It’s important to note that while blood work can provide valuable information, it is not the sole factor in diagnosing a rheumatic condition. Rheumatologists consider the patient’s symptoms, medical history, physical examination findings, and other diagnostic tests in conjunction with blood work to make an accurate diagnosis and develop an appropriate treatment plan.