Analysis of an iodide radioimmunoassay for 11-deoxicortisol measurement

作者：de Oliveira Madeira Joao Luiz; Bussmann Luciane Zgoda; Lima Valassi Helena Panteliou; de Mendonca Berenice Bilharinho

来源：Arquivos Brasileiros de Endocrinologia e Metabologia, 2014, 58(3): 232-236.

DOI：10.1590/0004-2730000002616

• 11-deoxycortisol
• radioimmunoassay
• mass spectrometry
• congenital adrenal hyperplasia

Objective: Our aim was to correlate 11-deoxycortisol levels obtained by two currently available techniques for 11-deoxycortisol measurement: radioimmunoassay, and high performance liquid chromatography followed by tandem mass spectrometry (MS/MS). The latter is the gold standard method for steroid hormone measurement. Materials and methods: We selected 88 samples and the results of these two methods were compared by Deming regression. Results: The analytical sensitivity of the RIA was 0.30 ng/mL, with inadequate linearity and inadequate precision profile (34% of the samples had a CV >= 20%). From the selected samples, 54 had measurable levels of 11-deoxycortisol in both methods and were used in the comparison. The comparison of RIA with LC-MS/MS showed an overestimation of the results by RIA. The correlation coefficient was 0.610; linear regression slope was 3.751; and the intercept was 0.145, indicating a poor correlation between the two methods. Conclusion: We concluded that 11-deoxycortisol measured by radioimmunoassay, despite a good analytical sensitivity, showed very low specificity, precluding its use as a reliable method for 11-deoxycortisol measurement.

• 出版日期2014-4