Skip to content

Pneumonia Immunoglobulin G (IgG) Titers (Serum)

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

This test measures the level of Immunoglobulin G (IgG) antibodies in your blood. IgG is a type of antibody that helps your immune system fight infections, including pneumonia.

Quick summary

["IgG antibodies help your body remember past infections and fight future ones, including pneumonia caused by bacteria or viruses."]

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

Key facts at a glance

LOINC
5258-9
Short code
M pneumo IgM Titr Ser IF
Synonyms
M pneumo IgM Titr Ser IF
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
if
CPT
82784
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 key part of your immune response. They are produced after you’ve been exposed to a pathogen (like bacteria or viruses) and help your body defend against it. This test checks how much IgG your body has made in response to a specific type of pneumonia infection.

Why Might You Need This Test?

Your healthcare provider may order this test if you’ve had pneumonia or are at risk of getting it again. It can help determine if your immune system is effectively fighting the infection or if you need additional support, such as vaccines or treatments.

How Is This Test Done?

A blood sample is taken from a vein in your arm. The blood is then sent to a lab where it is analyzed to measure the IgG antibody levels related to pneumonia.

What Do My Results Mean?

Higher IgG levels may indicate that your body has successfully produced antibodies to fight the infection. Lower levels could suggest that your immune response is weaker or that you may need further medical evaluation.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

IgG Antibody Levels for Pneumonia

Frequently asked questions

How long after pneumonia do IgG levels stay elevated?
IgG antibodies can remain in your system for months or even years after an infection. They provide long-term immunity, which is why vaccines like the pneumococcal vaccine work by boosting IgG levels against specific bacteria.
Can IgG levels help predict if I’ll get pneumonia again?
While IgG levels can indicate past exposure and immunity, they don’t always predict future risk. Other factors, like overall health, lifestyle, and vaccination status, play a bigger role in preventing recurrent infections.
What if my IgG levels are low?
Low IgG levels might suggest a weaker immune response, which could increase your risk of infections. Your healthcare provider may recommend additional vaccines, immune-boosting treatments, or further testing to understand your immune function better.
  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