Beta 2 Microglobulin
- Sample Type
- Serum
- Fasting
- No
- Unit
- mg/L
Function
Beta-2 Microglobulin (B2M) is a protein found on the surface of nearly all nucleated cells and is part of the MHC Class I molecule. It is shed into the blood in small amounts. Since it is cleared by the kidneys, its concentration reflects both cell turnover and renal filtration efficiency.
Why it is Ordered
In oncology, B2M is used as a prognostic marker for certain blood cancers. While it cannot diagnose cancer on its own, its level correlates with tumor burden and growth rate. It is also used to assess kidney function, particularly tubular damage.
Associated Conditions
- Multiple Myeloma: Used for staging (International Staging System).
- Chronic Lymphocytic Leukemia (CLL) & Lymphoma: Indicators of disease activity.
- Kidney Disease: High levels can indicate renal failure or tubular injury.
- Inflammatory States: Elevated in HIV and certain autoimmune conditions.
Check Your Result
Check Your Result
Enter your lab result to see where you stand compared to the standard reference range.
Why Context Matters
B2M is non-specific. An elevated result does not automatically mean cancer; it could be caused by benign conditions like kidney dysfunction or simple viral infections. Because levels increase as kidney function decreases, an 'abnormal' oncology result might actually be a 'normal' result for someone with mild renal impairment. Always cross-reference B2M with Creatinine and GFR tests.
Lab ranges are statistical averages, not biological laws. "Normal" for a 20-year-old male isn't normal for a 60-year-old female.
Clinical References
Source-of-truth databases and clinical guidelines for Beta 2 Microglobulin:
Official Sources
- Multiple Myeloma, Version 2.2024, NCCN Clinical Practice Guidelines in Oncology - PubMedpubmed.ncbi.nlm.nih.gov
- NCCN Guidelines® Insights: Multiple Myeloma, Version 1.2025 - PubMedpubmed.ncbi.nlm.nih.gov
Research & Guidelines
- PubMed: Beta 2 Microglobulin Clinical GuidelinesNCBI / PubMed
Related Indicators
Medically Reviewed by Dr. Binoy Babu, MBBS
Board Certified Doctor • 10+ Years Clinical Experience
Dr. Babu is a practicing physician dedicated to empowering patients with clear, actionable medical information. He founded 2opi to bridge the gap between complex lab reports and patient understanding, ensuring everyone has access to a reliable second opinion.
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