From the Guidelines
An elevated sedimentation rate (sed rate) is primarily caused by inflammation in the body, which can be due to various factors such as infections, autoimmune disorders, cancers, tissue injury, or trauma. When inflammation occurs, the liver produces proteins called acute phase reactants, particularly fibrinogen, which cause red blood cells to stick together and fall more quickly in the test tube during the sedimentation rate test.
Common Causes of Elevated Sed Rate
- Infections (bacterial, viral, or fungal)
- Autoimmune disorders (like rheumatoid arthritis, lupus, or inflammatory bowel disease) 1
- Cancers (especially lymphomas and multiple myeloma)
- Tissue injury or trauma
- Chronic inflammatory conditions Age can also affect sed rates, with older individuals typically having higher baseline levels. Pregnancy and certain medications like oral contraceptives may elevate sed rates without indicating disease.
Diagnostic Considerations
The sed rate is a non-specific test, meaning it can't identify the exact cause of inflammation, but rather indicates that inflammation is present somewhere in the body. This test is often used alongside other more specific tests to help diagnose conditions or monitor disease activity and treatment response in inflammatory disorders. For instance, in the diagnosis of osteomyelitis, a highly elevated sed rate (usually defined as >70 mm/h) increases the likelihood of osteomyelitis underlying a diabetic foot wound 1. Similarly, in pediatric patients, an elevated erythrocyte sedimentation rate is one of the Kocher criteria used to distinguish septic arthritis from transient synovitis 1.
Clinical Application
In clinical practice, it is essential to consider the sed rate in the context of other clinical findings and diagnostic tests to determine the underlying cause of inflammation and guide appropriate management. Elevated sed rates should prompt further investigation to identify the underlying cause of inflammation, and treatment should be tailored to address the specific condition.
From the Research
Causes of Elevated Sedimentation Rate
Elevated sedimentation rate (sed rate) is a marker of inflammation in the body. Several conditions can cause an elevated sed rate, including:
- Infections such as tuberculosis 2 and acute rheumatic fever 3
- Autoimmune disorders like rheumatoid arthritis 4, 5, 6
- Inflammatory diseases, including those affecting the lungs 4
- Cardiovascular diseases, such as rheumatic heart disease 3
Infections and Elevated Sed Rate
Infections like tuberculosis can cause an elevated sed rate, as seen in tuberculous endocarditis 2. Acute rheumatic fever, caused by Group A Streptococcus, can also lead to an elevated sed rate 3.
Autoimmune Disorders and Elevated Sed Rate
Rheumatoid arthritis is a common autoimmune disorder that can cause an elevated sed rate 4, 5, 6. The disease activity and medication used to treat rheumatoid arthritis can also impact the sed rate, with high disease activity prior to admission predicting increased mortality in patients with pneumonia 5.
Other Conditions and Elevated Sed Rate
Other conditions, such as lung involvements in rheumatic diseases, can also cause an elevated sed rate 4. Rheumatic heart disease, a complication of acute rheumatic fever, can also lead to an elevated sed rate 3.