Serum Soybean Agglutinin (SBA) Test (Qualitative)
This test measures the presence of antibodies in your blood that react with soybean agglutinin, a protein found in soybeans. It helps assess immune system responses, particularly in conditions like lupus or other autoimmune diseases.
["The SBA test helps doctors check for certain immune-related conditions by detecting unusual antibody activity."]
Key facts at a glance
- LOINC
- 102690-5
- Short code
- Soybean IgG RAST
- Synonyms
- Soybean IgG RAST
- Category
- glucose
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 10
- Ref high
- 40
- Critical range
- — – 500 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- rast
- CPT
- 84484
- SNOMED
- 302774002
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
What Does the SBA Test Measure?
The SBA test detects whether your blood contains antibodies that bind to soybean agglutinin. Normally, these antibodies are not present in healthy individuals. If they are found, it may indicate an immune response that could be linked to autoimmune disorders or other conditions affecting the immune system.
Why Might Your Doctor Order This Test?
Your doctor may recommend this test if you have symptoms or a history of autoimmune diseases, such as systemic lupus erythematosus (SLE), rheumatoid arthritis, or other conditions where the immune system mistakenly attacks healthy tissues. It can also be part of a broader evaluation for unexplained immune-related symptoms.
How Is the SBA Test Performed?
A blood sample is drawn from a vein, usually in your arm. The sample is then tested in a lab to check for the presence of antibodies that react with soybean agglutinin. The result is reported as either positive or negative.
What Are Possible Results and Next Steps?
A positive result suggests the presence of abnormal antibodies, which may warrant further testing or evaluation by your healthcare provider to determine the underlying cause. A negative result means no abnormal antibodies were detected in this test, but other tests or evaluations may still be needed.
Reference range
Adult: 10-40 U/LN/A
No special preparation required. Avoid fatty meals before the test if possible.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
SBA Test
Frequently asked questions
What does a positive SBA test mean?
Can a positive SBA test replace other diagnostic tests?
How often should I get this test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 17, 2026. · Read our editorial policy