The degree of urinary hypercortisolism is not correlated with the severity of cushing's syndrome.
described by Streit et al. (12 ) when analyte-free samples are not available. Our method is specific, sensitive, reproducible, and accurate (see Table 1 of the online Data Supplement). A 96-well plate format sample pretreatment in combination with LC-MS/MS for homocysteine analysis has been described previously (7, 9). We consider the combination of this format with a large plasma dilution without deproteinization for high-throughput homocysteine analysis the most important aspect of our application.