Beta-2 Microglobulin, Serum, Urine, Cerebrospinal Fluid
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Beta-2 Microglobulin, Serum, Urine, Cerebrospinal Fluid
Definition
- Ž ²2-Microglobulin is a cell membrane " “associated 100-amino-acid peptide, a component of the lymphocyte HLA complex. Because it is present on all nucleated cells and is almost totally reabsorbed and catabolized by the proximal tubules, it serves as a marker of immune activation and proximal tubular function. It is found in nearly all body fluids.
- Normal range: Serum: males: 0.60 " “2.28 mg/L; females: 0.60 " “2.45 mg/L Urine: 0 " “300 Ž ¼g/L CSF: 1.5 + 0.2 mg/L
- Serum: males: 0.60 " “2.28 mg/L; females: 0.60 " “2.45 mg/L
- Urine: 0 " “300 Ž ¼g/L
- CSF: 1.5 + 0.2 mg/L
Use
- Prognostic marker for some lymphoproliferative disorders (adult acute lymphocytic leukemia, AIDS).
- Prognosis assessment of multiple myeloma (as a tumor marker, it reflects burden of tumor cells).
- Evaluation of renal tubular disorders, index of GFR.
- CSF Ž ²2-microglobulin levels have been used as a disease indicator of a variety of conditions, including multiple sclerosis, neuro-Beh ƒ §et disease, sarcoidosis, AIDS " “dementia complex, and meningeal metastases, especially meningeal dissemination of acute leukemia and malignant lymphoma.
Interpretation
Increased In
- AIDS
- Aminoglycoside toxicity
- Amyloidosis
- Autoimmune disorders
- Breast cancer
- Crohn disease
- Felty syndrome
- Hepatitis
- Hepatoma
- Hyperthyroidism
- Inflammation of all types
- Leukemia (chronic lymphocytic)
- Lung cancer
- Lymphoma
- Multiple myeloma
- Poisoning with heavy metals, such as mercury or cadmium
- Renal dialysis
- Renal disease (glomerular): serum only; renal disease (tubular): urine only
- Sarcoidosis
- SLE
- Vasculitis
- Viral infections (e.g., CMV)
Decreased In
- Renal disease (glomerular): urine only; renal disease (tubular): serum only
- Response to zidovudine (AZT)
Limitations
- Drugs and proteins that may increase serum Ž ²2-microglobulin levels include cefuroxime, cyclosporin A, gentamicin, interferon-α, pentoxifylline, tumor necrosis factor, lithium, and radiographic contrast media.
- Drugs that may decrease serum Ž ²2-microglobulin levels include zidovudine.
- Drugs that may increase urine Ž ²2-microglobulin levels include azathioprine, cisplatin, cyclosporin A, furosemide, gentamicin, mannitol, nifedipine, sisomicin, and tobramycin.
- Drugs that may decrease urine Ž ²2-microglobulin levels include cilostazol.