title: beta 2-Microglobulin clearance as measured by radioimmunoassay.
abstract: We describe a radioimmunoassay for beta 2-microglobulin (beta 2 mu) in serum and urine. We incubated aliquots of diluted samples at room temperature for 1 h with 125I-labeled beta 2 mu and a rabbit antiserum monospecific for human beta 2 mu, and separated the phases by the double-antibody technique. The logit-log transformed dose-response curve was linear in the range 2 to 64 ng, equivalent to 0.5 to 16 mg/L of serum and 0.5 to 320 mg/L of urine. Assay sensitivity was 2.4 ng of beta 2 mu. Validation studies included tests of precision, accuracy, antibody specificity, and parallelism of the dose-response curves for standard and unknown. In a study of 25 normal individuals, serum and urine beta 2 mu ranged from 1.1 to 2.3 mg/L and 40 to 360 micrograms/24 h; the clearance of beta 2 mu was 8 to 130 microL/min. In 21 renal allograft recipients tested one to five weeks after transplantation, serum and urine beta 2 mu ranged from 3.9 to 15.6 mg/L and 7.2 to 611 mg/24 h; beta 2 mu clearance was 0.60 to 33.3 mL/min. Values for both serum and urine correlated well with severity of allograft rejection.
mesh_terms: D001609:Beta-Globulins / Q000378:metabolism*; D005198:Fanconi Syndrome / Q000276:immunology; D006084:Graft Rejection; D006801:Humans; D007457:Iodine Radioisotopes; D016030:Kidney Transplantation; D007700:Kinetics; D011863:Radioimmunoassay / Q000379:methods; D011865:Radioisotope Dilution Technique; D012016:Reference Values; D014184:Transplantation, Homologous; D001613:beta 2-Microglobulin / Q000378:metabolism* / Q000652:urine
chemical_list: D001609:Beta-Globulins; D007457:Iodine Radioisotopes; D001613:beta 2-Microglobulin