Beta-2 Microglobulin
A blood test that measures beta-2 microglobulin levels, which can help assess kidney function and serve as a tumor marker for certain blood cancers.
Order this test
LevelPanel has no business or affiliate relationship with Quest or LabCorp. These links are provided as a public service.
Lab testing services linked from this site are not available to residents of Alaska, Arizona, or Hawaii, unless otherwise noted on the lab's own website.
This publication is not intended to solicit the purchase of laboratory testing from any individual consumer.
What this test measures
Beta-2 microglobulin (B2M) is a small protein found on the surface of nearly all cells in the body, with particularly high concentrations on immune system cells including lymphocytes. As cells turn over naturally or are destroyed by disease, B2M is shed into the bloodstream, where it is normally filtered out by the kidneys.
Elevated blood levels of B2M can arise from two main categories of conditions: those that increase cell turnover (such as lymphomas, multiple myeloma, and chronic lymphocytic leukemia) and those that impair kidney filtration (since the kidneys are responsible for clearing B2M from the blood). In the context of blood cancers, B2M serves primarily as a prognostic marker, helping healthcare providers estimate disease severity and likely progression rather than diagnose the cancer itself. In kidney disease, elevated B2M reflects reduced filtration capacity. This makes the test a relatively nonspecific marker that gains clinical meaning from the context in which it is ordered.
Who should consider this test
You might consider this test if you are experiencing any of the following:
- Individuals who have been diagnosed with blood cancers such as multiple myeloma, chronic lymphocytic leukemia, or lymphoma may benefit from this test to help monitor disease progression and assess treatment response.
- Those with existing kidney conditions or suspected kidney dysfunction may find this test useful, as abnormal beta-2 microglobulin levels can indicate problems with kidney filtration or tubular function.
- Patients with autoimmune disorders or chronic inflammatory conditions may consider this test, as elevated levels can reflect increased immune system activity.
- Individuals on long-term dialysis treatment may need regular monitoring of beta-2 microglobulin levels to assess the effectiveness of their treatment and watch for complications like dialysis-related amyloidosis.
- People with a family history of blood cancers or other conditions affecting the immune system may consider this test as part of routine health monitoring, though it cannot diagnose these conditions on its own.
What to expect
Preparation
No special preparation is required for this test. No fasting is necessary, and individuals can continue taking their regular medications unless specifically instructed otherwise by their healthcare provider.
Sample Type
The test requires a simple blood draw from a vein, typically in the arm. A small needle is used to collect the blood sample into a test tube or vial.
Collection
At the lab location, a healthcare professional will clean the area, insert a small needle, and collect the blood sample. The entire process typically takes less than five minutes and may involve a slight sting when the needle is inserted.
Turnaround
Results are typically available within 1-3 business days after the sample reaches the laboratory.
Understanding your results
Normal blood B2M levels for adults typically range from approximately 1.5 to 3.0 mg/L, though reference ranges may vary by laboratory. Elevated levels prompt investigation into two broad categories: increased cellular turnover (suggesting blood cancer or chronic inflammatory conditions) and impaired kidney clearance. In patients with known multiple myeloma or lymphoma, B2M is used as a staging and prognostic tool, with higher levels generally associated with more advanced or aggressive disease. Healthcare providers interpret B2M alongside other diagnostic markers, imaging findings, kidney function tests, and clinical context to determine its significance.
| Population | Reference Range | Notes |
|---|---|---|
| Adults | 1.5-3.0 mg/L | Normal range may vary between laboratories |
| Newborns | Up to 5.4 mg/L | Higher levels are considered normal in newborns |
Reference ranges may vary by laboratory and individual factors. Results should be interpreted by a healthcare provider in the context of your overall health.
What does a “Low” result mean?
Low beta-2 microglobulin levels typically indicate decreased disease activity in conditions where B2M is used as a prognostic marker, such as multiple myeloma, lymphoma, or leukemia, or may suggest the absence of such disease processes. In renal tubular disease specifically, serum levels may be low while urine levels are high. However, low levels alone are never used to rule out any particular condition without additional testing and clinical evaluation.
What does a “High” result mean?
Elevated beta-2 microglobulin levels may be associated with blood and bone marrow cancers such as multiple myeloma, chronic lymphocytic leukemia, or certain lymphomas. High levels can also occur in non-cancerous conditions including kidney dysfunction, chronic inflammation, liver disease, some acute viral infections, and various autoimmune disorders. Because elevated B2M can result from such a wide variety of conditions, healthcare providers typically do not use this test alone to diagnose any specific condition.
Privacy & confidentiality
All beta-2 microglobulin test results are completely confidential and protected under HIPAA regulations. Results are not shared with insurance companies, employers, or added to your permanent medical record without your consent, ensuring complete privacy for your health information.
Frequently asked questions
Related tests
Kidney Panel
Comprehensive kidney function evaluation when beta-2 microglobulin suggests kidney involvement
View TestComplete Blood Count (CBC)
Basic blood cancer screening to complement beta-2 microglobulin tumor marker results
View TestESR + CRP Panel
Assesses inflammation levels which may contribute to elevated beta-2 microglobulin
View TestLiver Panel
Liver disease can cause elevated beta-2 microglobulin levels
View TestRelated conditions
Last reviewed: April 2026
CPT Code: 82232
This test may not be available in: NY, NJ, RI
This page is for informational purposes only and does not constitute medical advice. Always consult with a healthcare provider regarding any health concerns. LevelPanel does not diagnose, treat, or prescribe.
Order this test
Choose your preferred lab
LevelPanel has no business or affiliate relationship with Quest or LabCorp. These links are provided as a public service.
Lab testing services linked from this site are not available to residents of Alaska, Arizona, or Hawaii, unless otherwise noted on the lab's own website.
This publication is not intended to solicit the purchase of laboratory testing from any individual consumer.
Not sure if this is the right test? Contact our care team for guidance.
This page is intentionally kept stable and machine-readable so that researchers, clinicians, and AI systems can rely on it as a reference. See our Citation Policy.