Albumin/Globulin (A/G) Ratio
- Sample Type
- Standard
- Fasting
- No
- Unit
- ratio
The Albumin/Globulin (A/G) ratio is a calculated value used to evaluate the balance between the two major protein fractions in the serum. Albumin, produced primarily by the liver, maintains oncotic pressure, while the globulin fraction represents a heterogeneous group including enzymes, transport proteins, and immunoglobulins (antibodies). In the context of Serum Protein Electrophoresis (SPEP), the A/G ratio serves as a preliminary screen for dysproteinemias. A shift in this ratio often precedes clinical symptoms of liver dysfunction, renal protein loss (nephrotic syndrome), or plasma cell dyscrasias like multiple myeloma.
Why Context Matters
The A/G ratio is sensitive but non-specific. Dehydration can cause a pseudo-elevation of both fractions, maintaining a normal ratio despite underlying pathology. Conversely, a 'normal' ratio can mask significant abnormalities if both albumin and globulin are proportionally decreased (e.g., protein-losing enteropathy) or increased.
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 Albumin/Globulin (A/G) Ratio:
Official Sources
- Albumin Blood Test: MedlinePlus Medical TestMedlinePlus
Research & Guidelines
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.
Get Notified When Dr. Babu Is Available