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Hepatitis A Virus Antibody, IgG, Reverse Passive Hemagglutination Test (Maximal Titration)

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

This test measures your body’s immune response to the Hepatitis A virus by detecting IgG antibodies. IgG antibodies develop after infection or vaccination and provide long-term protection.

Quick summary

["IgG antibodies indicate past exposure or immunity to Hepatitis A."]

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

Key facts at a glance

LOINC
29474-4
Short code
Hep v A-wave reversal.max DOP
Synonyms
Hep v A-wave reversal.max DOP
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
us-doppler
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 This Test Measures

The test uses a reverse passive hemagglutination (PAHA) method to detect IgG antibodies against Hepatitis A virus. This method involves mixing your blood sample with virus-specific particles and observing how antibodies bind to them. The maximal titration determines the highest dilution where antibodies still react, reflecting your immune response level.

Why It Matters in Medicine

IgG antibodies are critical for diagnosing past Hepatitis A infection or confirming immunity after vaccination. Unlike IgM antibodies (which appear shortly after infection), IgG persists longer and indicates sustained immunity.

Sample Collection and Preparation

This test requires a blood sample drawn from a vein, typically in a clinic or lab. The sample is processed to isolate serum (liquid part of blood without clotting factors) for antibody detection.

Common Reasons for Testing

Doctors may order this test if you have symptoms of Hepatitis A (e.g., fatigue, nausea, jaundice), if you’ve traveled to regions with high Hepatitis A risk, or if you’re planning travel to such areas to ensure immunity.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

IgG Hepatitis A Antibody (Reverse PAHA Max)

Frequently asked questions

Why might my doctor want to know if I have Hepatitis A antibodies?
A positive result suggests you’ve had Hepatitis A in the past or received the vaccine, providing protection against future infection. A negative result means you may need vaccination or further testing for active infection.
What does a positive result mean for my health?
A positive IgG result means your body has developed immunity through either natural infection or vaccination. This does not indicate an active infection but confirms protection. If you’re unsure about vaccination history, discuss this with your doctor.
How long do these antibodies last?
IgG antibodies typically remain in your system for years, often lifelong, after infection or vaccination. However, antibody levels can decline over time, so some people may need booster vaccinations or antibody testing for long-term protection.
  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