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Immunoglobulin G (IgG) Subclass 2 Concentration (Serum/Plasma)

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

This test measures the amount of Immunoglobulin G (IgG) subclass 2, a type of antibody in your blood. IgG antibodies help fight infections and are important for long-term immunity.

Quick summary

["IgG2 helps protect against certain bacteria and viruses, and low levels may affect your immune response."]

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

Key facts at a glance

LOINC
77678-1
Short code
IGF-I 2.5h p chal SerPl-mCnc
Synonyms
IGF-I 2.5h p chal SerPl-mCnc
Category
hormone
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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 IgG2 Serve in Your Body?

IgG2 is one of five subclasses of Immunoglobulin G (IgG), the most common antibody in your blood. It plays a key role in defending against certain types of bacteria, such as those causing respiratory infections. IgG2 antibodies help neutralize toxins and pathogens, contributing to your body’s ability to fight off infections over time.

Why Might Your Doctor Order This Test?

Your doctor may recommend this test if you have symptoms of a weakened immune system, recurrent infections, or conditions like asthma, allergies, or certain autoimmune diseases. It can also be part of an evaluation for primary immunodeficiency disorders.

What to Expect Before the Test

No special preparation is needed for this blood test. You may have a small needle inserted into your arm to draw blood, similar to other routine blood tests. If you’re on blood thinners or have a history of bleeding issues, let your healthcare provider know.

What Are Possible Results?

Results are typically reported as a mass concentration in grams per liter (g/L) or milligrams per deciliter (mg/dL). Your doctor will compare your result to a reference range appropriate for your age and health status.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

IgG2 Level

Frequently asked questions

Why might my IgG2 levels be checked during pregnancy?
IgG2 levels are not typically checked during pregnancy unless there are specific concerns about immune function, such as recurrent infections or autoimmune conditions. Pregnancy itself does not usually require this test unless your doctor suspects an underlying immune issue.
Could diet or supplements affect IgG2 levels?
Dietary factors, such as a balanced intake of proteins, vitamins, and minerals, can support overall immune function, but they do not directly influence IgG2 levels. Supplements like zinc or vitamin D may support immune health indirectly, but they won’t change IgG2 test results.
What if my IgG2 test result is outside the normal range?
If your IgG2 level is outside the normal range, your doctor will discuss the findings with you. They may recommend further testing, lifestyle adjustments, or treatment options based on your overall health and symptoms. Follow-up may include additional immune function tests or consultations with an immunologist.
  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