Electrochemiluminescence immunoassay method underestimates cortisol suppression in ulcerative colitis patients treated with oral prednisone

Figure 3 Difference between electrochemiluminescence immunoassay and liquid chromatography-tandem mass spectrometry methods using log_e-transformed data in the 12 patients with cortisol levels below the limit of quantification. LC-MS/MS: Liquid chromatographic methods coupled with mass spectrometry detection; ECLIA: Electrochemiluminescence immunoassay.