Establishment of radioimmunoassay for human macrophage colony-stimulating factor using recombinant human macrophage colony-stimulating factor as tracer and immunogen

A sensitive and reliable radioimmunoassay (RIA) for human macrophage colony-stimulating factor (M-CSF) was developed using recombinant human M-CSF (rhM-CSF) as tracer and immunogen. The assay was quantitative over the range of 50 pg/ml and 5.0 ng/ml for M-CSF in human urine and serum, and more sensitive and specific than the murine bone marrow assay. The average level of human M-CSF in urine from normal males (N = 71) and females (N = 46) was 3.94 ± 1.78 ng/ml (2.85 ± 1.15 μg/g creatinine), and 3.53 ± 1.70ng/ml (3.31 ± 1.12 μg/g creatinine), respectively. The serum levels were 1.95 ± 0.38ng/ml for males (N = 117), and 1.93 ± 0.49 ng/ml for females, (N = 16). The results with the urine and sera showed that there was no difference in the M-CSF levels due to age or gender.