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Immunoassay for Donor-Specific Antibody to Donor IgG Immunoglobulin (IgG) in Recipient Plasma (IgG Inhibition Test)

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

This test measures antibodies in your blood that may react with donor IgG, often used in blood transfusion compatibility checks.

Quick summary

["Helps ensure safe blood transfusions by checking for potential immune reactions to donor proteins."]

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

Key facts at a glance

LOINC
50999-2
Short code
L donovani IgG+IgM Ser-Imp
Synonyms
L donovani IgG+IgM Ser-Imp
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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

Why This Test Is Done

Your healthcare provider may order this test if you’ve received blood transfusions recently or if you’re at higher risk of transfusion reactions, such as those with autoimmune conditions or previous transfusion complications. It helps identify if your immune system is producing antibodies against donor proteins, which could affect future transfusions.

How the Test Works

A small sample of your plasma is mixed with donor IgG and tested for antibody binding. If antibodies are present, they’ll bind to donor IgG, preventing detection by the immunoassay method. This reaction is measured to determine compatibility.

What to Expect Before the Test

No special preparation is needed. You may have a blood draw from a vein in your arm, similar to other blood tests. If you’re receiving transfusions, discuss this test with your doctor beforehand to ensure timing aligns with your treatment plan.

What to Expect After the Test

You’ll likely feel minor discomfort at the injection site, but no other effects. Results may take several days to weeks, depending on lab processing and follow-up needs.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

IgG Inhibition Test

Frequently asked questions

If positive, this test indicates your immune system may reject donor proteins in future transfusions. It guides doctors to select compatible blood components or adjust transfusion protocols to prevent adverse reactions.
This test is primarily used in transfusion medicine to assess compatibility between donor and recipient blood products, especially in high-risk patients.
What does a positive result mean?
A positive result suggests your immune system has antibodies that could react with donor IgG, potentially causing transfusion-related issues. Your doctor will work with you to find safer blood options or monitor closely during transfusions.
How long does it take to get results?
Results typically take 5–14 business days, depending on lab workflow and follow-up requirements. Your doctor will contact you once results are available.
  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