Abstract
A highly sensitive IRMA for serum C-peptide (CPR), whose sensitivity was 0.01ng/ml and 10 times higher than that of the commercially available RIA kit (RIA kit), was developed. serum CPR was undetectable by the IRMA in27of52juvenile type-1diabetics. This may reflect the clinical reflect the clinical characteristics of type-1diabetes, i, e., that secretion of insulin is often suppressed. CPR was undetectable by the IRMA in serum treated with charcoal and serum from patients who had undergone total pancreatectomy but values of 0.17-0.23ng/ml were determmed with the RIA kit (RIA kit, Shionogi, Osaka, Japan). In a dilution test of two patients' sera diluted with CPR-free serum and the serum of a patient who had undergone total pancreatectomy, linearity of the dilution line from point 0 was observed with the IRMA but not RIA kit. Thus, the lower serum CPR values obtained by the IRMA might be more reliable than those obtained with the RIA kit. A good correlation was obtained between the semlm glucose values and CPR values measured by the IRMA and RIA kit, although the CPR values obtained with the IRMA were lower than those obtained with the RIA kit. Serum CPR values in juvenile type-1diabetics measured by the IRMA were well correlated with those determined with the commercial RIA kit, although CPR vahles by the former were lower than those obtained with the latter.
