Carlson M G, Snead W L, Oeser A M, Butler M G
Department of Medicine, John F. Kennedy Center for Research on Human Development, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-6303, USA.
J Lab Clin Med. 1999 Jan;133(1):75-80. doi: 10.1053/lc.1999.v133.a94437.
Immunoassays for circulating leptin are important research tools for examining the role and regulation of leptin expression in human obesity. However, uncertainty exists regarding the comparability between studies of reported plasma or serum leptin concentrations. The purpose of the present study was to directly compare plasma leptin concentrations by using two of the most widely reported immunoassay methods-namely, a commercially available radioimmunoassay (RIA) and a proprietary enzyme-linked immunosorbent assay (ELISA). Plasma leptin concentrations were measured in healthy lean and obese volunteers and in patients with Prader-Willi syndrome (PWS). Over a wide range of plasma concentrations (2 to 70 ng/mL), leptin measurements obtained with the RIA and ELISA methods were highly correlated (r = 0.957, P<.0001) and were essentially indistinguishable. Leptin levels measured by RIA and ELISA were highly correlated with body mass index (BMI) overall (r = 0.784, P<.0001 and r = 0.732, P<.0001, respectively) and in the lean and obese subgroups. When compared with the results in the lean individuals (mean +/- SEM, 11.6+/-3.2 ng/mL), plasma leptin was significantly higher in both the obese (35.5+/-4.0 ng/mL, P<.0001) and the PWS subjects (30.7+/-6.9 ng/mL, P<.05). However, after we controlled for differences in BMI, the leptin levels were similar in all three groups. In conclusion, we found that the RIA and ELISA used in the present study yield plasma leptin concentrations that are essentially indistinguishable. Our findings should facilitate comparisons of leptin levels measured by these two widely used immunoassays in previous and future studies that examine the role of leptin in body weight regulation.
用于检测循环瘦素的免疫测定法是研究瘦素表达在人类肥胖中的作用及调节机制的重要研究工具。然而，关于已报道的血浆或血清瘦素浓度研究之间的可比性仍存在不确定性。本研究的目的是通过使用两种最广泛报道的免疫测定方法，即市售放射免疫测定法（RIA）和一种专利酶联免疫吸附测定法（ELISA），直接比较血浆瘦素浓度。在健康的瘦人和肥胖志愿者以及普拉德-威利综合征（PWS）患者中测量血浆瘦素浓度。在广泛的血浆浓度范围（2至70 ng/mL）内，用RIA和ELISA方法获得的瘦素测量值高度相关（r = 0.957，P<0.0001），且基本无差异。RIA和ELISA测量的瘦素水平总体上与体重指数（BMI）高度相关（分别为r = 0.784，P<0.0001和r = 0.732，P<0.0001），在瘦人和肥胖亚组中也是如此。与瘦人个体的结果（均值±SEM，11.6±3.2 ng/mL）相比，肥胖者（35.5±4.0 ng/mL，P<0.0001）和PWS受试者（30.7±6.9 ng/mL，P<0.05）的血浆瘦素均显著更高。然而，在我们控制了BMI差异后，三组的瘦素水平相似。总之，我们发现本研究中使用的RIA和ELISA得出的血浆瘦素浓度基本无差异。我们的发现应有助于在先前和未来研究中比较这两种广泛使用的免疫测定法所测量的瘦素水平，这些研究旨在探讨瘦素在体重调节中的作用。
