Calcitonin levels in normal individuals with new highly sensitive chemiluminescent enzyme immunoassay.
Human serum calcitonin concentration in normal individuals was measured with a new assay based on the chemiluminescent enzyme immunoassay (CLEIA) method. The CLEIA assay was highly sensitive and was able to determine a calcitonin concentration of 0.04 pg/ml as sensitivity limit at a condition of 0+3SD. With this CLEIA assay, the mean value of calcitonin in males and females was 2.26 and 1.33 pg/ml, respectively, highlighting a significant difference between genders. The mean value and range of human serum calcitonin in this assay were approximately 1/10 those reported previously in competitive radioimmunoassay (RIA) methods. Since RIAs for calcitonin showed much variability at a low concentration range due to the competitive format, they seemed to lack the necessary sensitivity to cover the normal range and appeared only useful for hyper-calcitonin phenomenon in diseases such as medullary thyroid carcinoma. The CLEIA for calcitonin provided a lower detection limit than normal range, and it can therefore be assumed that it could be applied for the measurement of hypo-calcitonin phenomena typically found in some disorders such as osteoporosis.
Diagnostics Strategic Planning Department, Fujirebio, Inc., Tokyo, Japan.
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D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000097:blood*; D002116:Calcitonin / Q000097:blood*; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D008163:Luminescent Measurements; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012680:Sensitivity and Specificity; D012737:Sex Factors
D014408:Biomarkers, Tumor; D002116:Calcitonin