BETA-2-MICROGLOBULIN

CLINICAL UTILITY:

Beta-2 microglobulin is a protein found associated with the HLA-A, B and C antigens on all nucleated cells, and normally is shed into circulation and excreted through the kidneys at a relatively constant rate. Thus, increases in the serum level of this protein suggest impaired glomerular function, as reflected in the glomerular filtration rate (GFR), and increases in the urine level reflect the activity of proximal tubular cells.

Elevated serum levels of Beta-2 microglobulin serve as an aid in monitoring renal transplant patients for early rejection. Levels decline to normal following a successful transplant. Serial testing of the serum and urine levels of Beta-2 microglobulin are used to evaluate renal allograft function. Increased synthesis of the protein also contributes to elevated serum levels. Conditions associated with such increases include urinary myeloma, melanoma, autoimmune disease, AIDS (Acquired Immune Deficiency Syndrome), chronic inflammatory conditions, and infectious diseases such as infectious mononucleosis. Elevated cerebrospinal fluid levels of Beta-2 microglobulin have been reported in patients with CNS lymphomas or leukemia, and patients with CNS involvement with SLE.

METHOD DESCRIPTION:

Serum levels of Beta-2 microglobulin are determined antigenically by a turbidimetric method, using a multipe-specimen centrifugal analyzer.

REFERENCE RANGE:

Serum: 0-2.5 ug/ml
CSF: under investigation

SPECIMEN REQUIREMENTS:

0.3 ml serum. Freeze.