Clinical utility of an automated immunochemiluminometric thyroglobulin assay in differentiated thyroid carcinoma

BACKGROUND: Thyroglobulin (Tg) measurements are important in the follow-up of patients with differentiated thyroid carcinoma (DTC). We evaluated the analytical and clinical performance of a new automated immunochemiluminometric assay for Tg (Tg-ICMA; Nichols Advantage Tg; Nichols Institute Diagnostics). METHODS: We used the Tg-ICMA to measure Tg concentrations in serum samples from 110 Tg antibody-negative DTC patients undergoing thyroid-hormone suppression therapy. Disease state at the time of measurement was assessed on the basis of routine follow-up data. We compared the clinical performance of this assay with the routinely used IRMA (ELSA-hTG; CIS Bio International). RESULTS: The detection limit and functional sensitivity of the Tg-ICMA, based on direct calibration to CRM-457, were 0.05 and 0.6 microg/L, respectively. No Tg-IRMA-positive cases were missed by the Tg-ICMA. Tg was measurable by Tg-ICMA (0.6-8.6 microg/L) but undetectable by Tg-IRMA (<1.5 microg/L) in 12 patients (11%). Clinical data showed evidence of disease in 4 of 12 patients (33%). CONCLUSIONS: The Tg-ICMA is a sensitive and reproducible assay for identifying patients in follow-up for DTC with evidence of disease, but uncertainty remains with regard to interpreting findings of measurable serum Tg in patients with no evidence of disease. Follow-up data are required to determine the predictive value of these isolated Tg results. New concepts, i.e., serial Tg measurements and risk stratification of patients, need to be tested to confirm the applicability of this assay for clinical practice.     

老年阻塞性睡眠呼吸暂停综合征与心血管疾病的研究进展

0 引言 睡眠呼吸暂停综合征(sleep apnea syndrome, SAS)是指每晚7 h睡眠中出现持续10 s以上的呼吸暂停大于30次或睡眠呼吸暂停/低通气指数(AHI,即平均每小时呼吸暂停次数 低通气次数)≥5,60岁以上老年人AHI≥10.SAS分为三型,即阻塞性(obstructive sleep apnea, OSA)、中枢性(central sleep apnea, CSA)和混合性(mixed sleep apnea, MSA).