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Serum or Plasma Anti-Drug Antibody Level (Immunoassay)

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

This test checks for antibodies your immune system may produce against medications you’ve taken, which could affect how well they work.

Quick summary

["This test helps monitor drug resistance or immune reactions to certain treatments."]

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

Key facts at a glance

LOINC
22587-0
Short code
T palldm Ab Ser Ql
Synonyms
T palldm Ab Ser Ql
Category
chemistry
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

Why This Test Matters

Your doctor may order this test if you’re on medications like biologics (e.g., tumor necrosis factor inhibitors) or certain chemotherapy drugs. Antibodies can interfere with how these drugs function, potentially reducing their effectiveness or causing side effects.

What to Expect Before the Test

No special preparation is needed. You’ll provide a blood sample, usually drawn from your arm. The test is done on serum or plasma, depending on the lab’s method.

What the Results Mean

Results are qualitative (positive/negative) or semi-quantitative, indicating the presence or level of antibodies. A positive result means your body detected the drug as foreign, which may require adjustments to your treatment plan.

Common Uses

Doctors use this test to diagnose or manage conditions like autoimmune diseases (e.g., rheumatoid arthritis), infections, or to assess drug efficacy in cancer or inflammatory treatments.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical significance: Antibodies against drugs can signal immune-mediated issues, such as hypersensitivity reactions or reduced drug absorption. This test helps tailor treatment to avoid complications or optimize outcomes.

Short name

Anti-drug antibody test

Frequently asked questions

Why might my doctor ask for this test?
If you’re on a medication known to trigger antibody responses (e.g., biologics for arthritis or cancer), your doctor may check for these antibodies to adjust your treatment safely.
What does a positive result mean?
A positive result means your immune system recognized the drug as foreign, which could mean it’s working as intended (e.g., fighting disease) or causing side effects. Your doctor will discuss next steps, like changing medications or dosages.
Can I eat or drink before this test?
You can eat and drink normally unless instructed otherwise. Avoid alcohol 24 hours before the test, as it may affect blood chemistry results.
  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