beta-2 microglobulin in body fluid

Reference interval: (serum) 1) serum (mean values) a) 0.30 mg/dL, age = neonate b) 0.19 mg/dL, age < 60 years c) 0.21 mg/dL, age 60-69 years d) 0.24 mg/dL, age > 70 years 2) urine 24 hours = 0.03-0.37 mg/day 3) CSF: 1.5 +/-0.2 mg/L Specimen: 1) serum - analyze fresh or store at 4 degrees C or < 72 h - stable frozen at -20 degrees C for 6 months, or -70 degrees C indefinitely 2) urine 24 hour - centrifuge, adjust to pH 7.0, analyze fresh, - stable frozen at -20 degrees C for up to 1 year 3) CSF - centrifuge before analysis - analyze fresh or store at 4 degrees C for < 72 hours - stable frozen at -20 degrees C for 6 months, or indefinitely at -70 degrees C - specimens should NOT contain blood Interferences: 1) serum levels increased by a) cyclosporin b) lithium 2) urine levels increased by a) carboplatin b) cisplatin c) gentamicin d) nifedipine e) tobramycin f) X-ray contrast agents Clinical significance: - patients with systemic lupus erythematosus have anti beta-2 microglobulin - patients with Felty's syndrome have circulating immune complexes containing beta-2 microglobulin - monitoring may predict progression of HIV patients to AIDS, leukemia or lymphoma. - urine values may be useful for assessment of renal clearance if urine is alkalinized to prevent degradation.

Specific

beta-2 microglobulin in CSF beta-2 microglobulin in dialysis fluid beta-2 microglobulin in peritoneal fluid beta-2 microglobulin in pleural fluid beta-2 microglobulin in serum beta-2 microglobulin in urine

References

Clinical Guide to Laboratory Tests, 3rd edition, NW Tietz ed, WB Saunders, Philadelphia, 1995