Beta 2 microglobulin Test

Beta 2 Microglobulin, also known as B2M, is a protein found on the surface of the nucleated cells. It functions as part of the human immune system. B2M is regularly shed by cells into the blood and is also present in most body fluids. The highest level of the protein is found in blood and lower levels are found in spinal fluid and trace levels of urine.

B2M passes in the kidney through blood-filtering units called glomeruli. It is later reabsorbed by the proximal renal tubules (structures in the kidney that reclaim proteins, minerals, vitamins, water and other vital substances).

Generally, only small amounts of B2M are present in the urine. However, if the renal tubules stop working properly because of damage or infection, the B2M levels increase. This is because of the decreased capacity of proximal renal tubules to reabsorb the protein. At the same time, if the glomeruli in the kidneys are damaged, they can not filter out B2M. Thus, the level of the B2M rises in the blood.

If the doctor suspects any of this damage, he might ask you to take the Beta 2 Microglobulin test. The test is helpful to distinguish between glomerular and tubular disorders. Apart from that, you might be asked to take the Beta 2 Microglobulin test for the following:

• For kidney disease, doctors can prescribe Beta 2 microglobulin blood tests and urine tests.
• It is used to monitor patients with end-stage renal disease.
• Patients undergoing long-term dialysis can experience an accumulation of B2M in their joints. This condition is known as dialysis-related amyloidosis. In such a scenario, a B2M profile test can be useful.
• Beta 2 Microglobulin test is also ordered when a patient experiences renal failure, as it provides additional information about the patient's kidneys.
• A doctor can ask for Beta 2 microglobulin tests if a patient has recently had a kidney transplant. It helps in monitoring and detecting early signs of rejection.
• Doctors will also ask to take the Beta 2 microglobulin profile test to monitor people exposed to high levels of cadmium or other heavy metals like mercury.
• B2M levels can also increase in the system because of overactive cell turnover. The Beta 2 Microglobulin test is also prescribed when the immune system shows symptoms of being overtly activated.

The imbalance of B2M levels in the system can lead to symptoms like fatigue, weakness and nausea. You can also have swelling or puffiness around the eyes or in the face, foamy urine, pink, brownish or bloody. Sometimes the levels of B2M are also elevated in certain conditions like chronic inflammation, liver disease, acute viral infections and hematologic malignancies associated with the B-lymphocyte lineage.

India experiences its share of chronic kidney diseases. The approximate prevalence of chronic kidney diseases in India is 800 per million and end-stage renal disease at approximately 150 to 200 per million. Some kidney diseases elevate due to unhealthy and dormant lifestyle choices. Nutrition and food also play a major part in this.

Kidney disorders

The B2M profile test measures the B2M levels in the body. Elevated levels of B2M are indicated if a person is experiencing the following symptoms:

• Urine which is blood, foamy, brownish or pink
• Swelling or puffiness around the eyes, which is known as oedema
• Swelling or puffiness around the wrists and ankles or in the face
• Fatigue or weakness
• Nausea
• Protein in the urine

For people with such complaints, amongst other tests, the Beta 2 Microglobulin profile test is prescribed by the consulting physician.

Some disease conditions for which this test can be prescribed are:

• End-stage renal disease or renal dysfunction
• Dialysis related amyloidosis
• Kidney transplant
• Chronic inflammation
• Liver disease
• Acute viral infections
• Different malignancies like hematologic malignancies associated with the B-lymphocyte lineage

Once the consulting physician initiates the treatment after the diagnosis, the Beta 2 microglobulin test is prescribed every month or three months to monitor and regulate the dosage based on your condition. The Beta 2 microglobulin profile test results will help your doctor continue the same treatment or modify the dosage of the ongoing medicines.

The Beta 2 microglobulin test is applicable for males and females, both adults and children.

A random Beta 2 Microglobulin Test helps with the diagnosis of kidney damage or other similar conditions. If the test results confirm a diagnosis, appropriate medication should be taken under an expert’s guidance.

The Beta 2 Microglobulin Test might be asked by your doctor every month or three months, based on your condition. You will have to take the test so that the doctor can monitor the effectiveness of the treatment and medication. This will also help the doctor to understand if they want to continue with the same medication or make amendments. The test can be annual if the results of the Beta 2 Microglobulin test are normal.

Before the Test

Your doctor will likely not request any special precautions before you take the Beta 2 Microglobulin test. However, if you need to undergo this test along with another that requires fasting or preparation, you may be advised to fast for a specific time. Please contact your doctor for detailed information.

During the Test

During the Beta 2 Microglobulin test, a blood sample from a vein in your arm will be drawn. Here are the consecutive steps:

• The potential puncture site will be cleansed using antiseptic solution.
• To make your veins stand out prominently, a tourniquet will be tied around your arm.
• A needle will be inserted into a vein to draw the blood. This can be accompanied by a brief pinch.
• The blood will be collected in a vial or small test tube, and a label with your details will be affixed to it.

After the Test

After the blood has been drawn:

• A bandage will be applied to stop the bleeding at the needle-insertion site.
• You may bruise at the puncture site. If you feel lightheaded (unusual side effect), rest for a few minutes till you feel better.
• If you experience persistent bleeding, pain, or if rashes erupt at the puncture site, contact your healthcare provider.

The Beta 2 Microglobulin Test measures the B2M levels in the body. The value gives an idea about kidney disorders. It can also help in detecting physical or internal damage to the kidney.

The result of the Beta 2 Microglobulin Test is not expressed as positive or negative. It is measured in mcg/mL.

If the value is lower than the normal range, then there is no problem in the body. However, if the value is higher than the normal range, then it is an indication of some problem in the body.

The test cannot evaluate the exact disease in the body. For that, other tests have to be taken along with the Beta 2 Microglobulin test, as advised by your consulting physician.

The normal range of B2M in the blood should be between 0.70 -1.80 mcg/mL. Anything that exceeds 1.80mcg/mL is an indication of a disorder in the body. However, if the B2M levels are lower than 0.70mcg/mL in the blood, then there is no problem. However, it is best to consult your doctor for the proper analysis and best guidance.

The normal values and reference ranges of the test may vary from lab to lab. Please refer to the ranges mentioned in the report and consult a doctor to understand the interpretation of lab reports.

The B2M levels in the blood can vary as compared to the normal range of 0.70-1.80 mcg/mL. Sometimes, B2M is undetectable in the blood and that is absolutely fine.

At the same time, if the results of the Beta 2 microglobulin test show elevated levels of B2M, i.e., higher than 1.80 mcg/mL, then that is considered borderline high and might be an indication of a problem. However, the results alone can’t diagnose a problem.

If someone already has a kidney-related disease and their B2M blood levels are elevated, that is a sign of glomeruli dysfunction.