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Pneumonia Immunoglobulin G (IgG) Titration (Serum)

Published: August 9, 2026Updated: August 16, 2026

This test measures the level of Immunoglobulin G (IgG) antibodies in your blood that may help identify past or current exposure to certain bacteria linked to pneumonia, such as *Streptococcus pneumoniae* or *Haemophilus influenzae*.

Quick summary

["IgG antibodies can indicate your immune system’s response to infections, aiding in diagnosis or monitoring of respiratory infections."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
6481-6
Short code
M pneumo IgG Titr Ser IF
Synonyms
M pneumo IgG Titr Ser IF
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
8
Ref high
61
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
if
CPT
82977
SNOMED
3110003
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 This Test Measure?

IgG antibodies are a type of protein produced by your immune system in response to infections. This test specifically looks for IgG levels against common bacteria that cause pneumonia. The presence of these antibodies suggests your body has either previously encountered these pathogens or is actively fighting them.

Why Might You Need This Test?

Doctors may order this test if you have symptoms of pneumonia, have a weakened immune system, or if you’ve been exposed to pneumonia-causing bacteria. It can also help evaluate long-term immune responses in certain conditions.

How Is the Test Performed?

A blood sample is taken from a vein in your arm. The sample is then processed to measure the specific IgG antibodies against pneumonia-causing bacteria using a sensitive immunoassay method.

What Do Results Mean?

Results are qualitative (present or absent) rather than numerical, indicating whether detectable IgG antibodies are present. High levels may suggest an active or past infection, while low or absent levels may indicate no prior exposure or immune response.

Reference range

Adult males: 8-61 U/L; Adult females: 5-36 U/LN/A

Specimen: serum

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

IgG Against Pneumonia Pathogens

Frequently asked questions

Why was this test ordered for me?
Your healthcare provider may have ordered this test to assess your immune response to pneumonia-causing bacteria, especially if you have symptoms of infection, a history of recurrent infections, or a condition that weakens your immune system.
What does a positive result mean?
A positive result means your blood contains IgG antibodies against pneumonia-causing bacteria, which could indicate you’ve had an infection in the past or are currently fighting one. This does not replace a clinical diagnosis but may support further evaluation.
Can this test replace a physical exam or other tests?
No, this test is one tool among many. It should be interpreted alongside your medical history, symptoms, and other diagnostic tests by your healthcare provider to guide treatment decisions.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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