26449 Beta-2 Microglobulin, Random, Urine (B2MU)

​B2MRUSO, U B2MRUSO, Beta-2 Microglobulin, Urine (FB2MU), Beta-2 Microglobulin, Urine (B2MU), Beta 2 Microglobulin Test, Beta-2 Microglobulin, Urine, B2M, (Beta-2 Microglobulin) Urine

​Evaluation of renal tubular damage

Monitoring exposure to cadmium and mercury

​Patient Preparation: For 12 hours before specimen collection, do not take multivitamins or dietary supplements containing biotin (vitamin B7), which is commonly found in hair, skin, and nail supplements and multivitamins.

Collection Instructions:

1. Patient should empty bladder.

2. Have patient drink at least 0.5 liters of water.

3. Within 1 hour, collect a random urine specimen.

4. Add 1 M sodium hydroxide (NaOH) as preservative to the collection. This preservative is intended to achieve a pH of between approximately 6 and 8.

​Degradation of beta-2 microglobulin occurs at pH <6.0.

​Beta-2 microglobulin is a low-molecular-weight protein that forms the light chain component of class I histocompatibility (HLA: human leukocyte antigen) antigens.

Increased urine levels are seen in proximal tubular renal damage due to a variety of causes, including cadmium, mercury, lithium, or aminoglycoside toxicity; pyelonephritis; and Balkan nephropathy, a chronic interstitial nephritis of unknown etiology.

​Increased excretion is consistent with renal tubular damage.

Beta-2 microglobulin excretion is increased 100 to 1000 times normal levels in cadmium-exposed workers.