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.
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.