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Monoclonal antibody titer (serum/plasma) by immunoassay

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

This test measures the amount of a specific monoclonal antibody in your blood, which may be used to monitor treatment response or detect certain immune conditions.

Quick summary

["Your doctor may order this test to track antibody levels for conditions like cancer, autoimmune diseases, or infections."]

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

Key facts at a glance

LOINC
15481-5
Short code
L inter Pomon Ab Titr Ser Aggl
Synonyms
L inter Pomon Ab Titr Ser Aggl
Category
coagulation
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
aggl
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

Doctors may request this test to evaluate how well a monoclonal antibody treatment is working, check for the presence of abnormal antibodies in your blood, or monitor immune responses in conditions like multiple myeloma, rheumatoid arthritis, or other disorders where monoclonal antibodies are involved.

What to Expect Before the Test

No special preparation is needed. You’ll have a small needle inserted into your arm or vein to draw blood. If you’re on blood-thinning medication, let your doctor know before the test.

What the Results Mean

Results are typically reported as a qualitative (positive/negative) or quantitative measurement of antibody concentration. High levels may indicate active treatment or disease, while low or absent levels could signal treatment effectiveness or an immune response.

Common Conditions Monitored

This test is often used in cancer care (e.g., for monoclonal antibodies like rituximab or trastuzumab) to assess treatment efficacy, detect relapse, or diagnose conditions like paraproteinemias (e.g., multiple myeloma).

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical significance: Elevated monoclonal antibody titers can signal ongoing disease activity, treatment resistance, or immune system involvement in autoimmune disorders. Low or undetectable levels may indicate successful treatment or immune suppression. Always discuss results with your healthcare provider.

Short name

Monoclonal Ab Titer

Frequently asked questions

What does a positive or negative result mean?
A positive result means your blood contains detectable levels of the specific monoclonal antibody being tested. This could mean you’re actively receiving treatment, your body is producing the antibody (e.g., in autoimmune conditions), or the antibody is present due to a disease like multiple myeloma. A negative result suggests the antibody is either not present or at very low levels.
How often will I need this test?
Frequency depends on your treatment plan and condition. Your doctor may order this test every few weeks, months, or as needed to monitor progress. Follow-up schedules are tailored to your specific diagnosis and treatment protocol.
Can I eat or drink before the blood draw?
You can eat and drink normally before the test unless instructed otherwise. Avoid alcohol or heavy meals 1–2 hours before the draw if your doctor specifies it, as it may affect blood flow or test 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