Antibody to Streptococcus pneumoniae (IgG) – Serum or Plasma
This test measures the level of antibodies your immune system produces in response to *Streptococcus pneumoniae* (pneumococcus), a common bacteria that can cause pneumonia, meningitis, or other infections.
["Helps assess immune response to pneumococcal infection or vaccination."]
Key facts at a glance
- LOINC
- 86144-3
- Short code
- S pneum Da 8 Ab Ser Ql IA
- Synonyms
- S pneum Da 8 Ab Ser Ql IA
- Category
- coagulation
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- ia
- 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
Why This Test Is Done
Your doctor may order this test if you’ve had symptoms of a pneumococcal infection (such as fever, cough, or confusion) or if you’re at higher risk for complications, like very young children, older adults, or people with weakened immune systems. It may also be used to check if your immune response to pneumococcal vaccination is working properly.
What to Expect Before the Test
No special preparation is needed. You’ll provide a blood sample, usually drawn from a vein in your arm. If you’re taking blood thinners, let your doctor know before the test.
What the Test Results Mean
Higher-than-normal levels may suggest recent infection or exposure to *Streptococcus pneumoniae*. Lower-than-expected levels could indicate a weakened immune response, especially after vaccination. Your doctor will interpret results in the context of your symptoms and medical history.
Common Causes of Abnormal Results
Elevated levels: Active pneumococcal infection, recent vaccination, or chronic exposure. Low levels: Possible immune deficiency, untreated infection, or improper vaccination response.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
This test helps diagnose or monitor pneumococcal infections, evaluate immune function, and guide vaccination decisions. It’s particularly useful in high-risk groups but isn’t definitive for infection alone—other tests (like blood cultures) may be needed for confirmation.
Short name
Strep pneumoniae antibody (IgG)
Frequently asked questions
What does a positive result mean?
Can this test be done at home?
How long does it take to get results?
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 16, 2026. · Read our editorial policy