Reference Intervals for Serum Calcitonin in Men, Women, and Children

The strategy currently used to investigate thyroid nodules in most cases involves measurement of calcitonin to exclude the possibility of medullary thyroid cancer (MTC). Techniques used to measure calcitonin have become more reliable, sensitive, and easy to perform. Automated nonisotopic techniques now exist, such as the Advantage® system.We found that some children have particularly high calcitonin. Previous reports also have shown that calcitonin is higher in young children (1)(2)(3)(4)(5)(6)(7)(8)(9), but most of these studies are now outdated and are based on immunoradiometric or even radioimmunologic (RIA) methods, which sometimes involve an extraction step. These techniques are also not very sensitive or specific (interference by procalcitonin). Because most studies addressing this subject investigated specific populations (premature infants, newborns, or hypotrophic or hypocalcemic children), we concluded that it would be useful to determine reference intervals for blood calcitonin in children with the Advantage system. Because the manufacturer (Nichols Institute Diagnostics) found a significant difference between men and women, we also evaluated this finding.The Advantage is an automated multiparametric random-access system that uses an acridinium ester chemiluminescence technique and a magnetic separation step (10)(11). The monoclonal antibodies used recognize the 11–23 (capture monoclonal antibody) and 21–32 (labeled monoclonal antibody) fragments of human calcitonin. …