Alpha 2 Macroglobulin Test

Alpha-2-Macroglobulin is a large plasma protein which despite being majorly produced by the liver, is also locally produced by macrophages, adrenocortical cells and fibroblasts. It is encoded by the A2M gene in humans. It is an important constituent of the blood. It acts as an anti-protease and is hence able to inactivate a huge number of proteinases. It functions as an inhibitor of fibrinolysis and coagulation. It acts as a carrier protein because it can bind to numerous growth factors and cytokines.

The test for Alpha-2-Macroglobulin is like a regular blood test where a blood sample is taken from a vein in the arm and the serum tested for A2M. Overnight fasting is preferred for this test. Also, it is advisable that you inform your doctor about any medications you’re undertaking (including nutritional supplements), in case he prescribes you this test. The doctor may ask you to stop certain medications in case they affect the results of your blood serum levels. It is advisable to wear light clothing, preferably with short sleeves for ease of collection of the blood samples.

The test for A2M is useful in the evaluation of patients with nephrotic syndrome and pancreatitis. Increased levels of alpha-2-macroglobulin are found in people with nephrotic syndrome in which other proteins with lower molecular weight are lost and alpha-2-macroglobulin is retained primarily because of its large size. Also, in patients with liver cirrhosis and diabetes, the levels of A2M are found to be elevated. Patients with acute pancreatitis have low serum concentrations which correlate directly with the severity of the disease. In cases of severe hepatic insufficiency or hyperfibrinolysis or after a major surgery or in septicemia, the measured levels of alpha-2-macroglobulin are often low. Patients with acute myocardial infarction along with a low concentration of A2M have a considerably better prognosis regarding the >1 year survival period.

The skin around the vein is cleaned by swabbing with 70% isopropyl alcohol to prevent contamination from any microorganisms. The lab technician then usually wraps an elastic band around your arm close to the venipuncture site to allow your veins to fill with blood. A needle is then used to draw several samples of blood from the arm. After the draw, the venipuncture site is covered with a Band-Aid. The blood sample is then submitted to a laboratory where it’s cultured, which may take anywhere between two to ten days.