Simplified method of determination of serum cholesterol sulfate by reverse phase thin-layer chromatography

A new method for determination of cholesterol sulfate (CS) and dehydroepiandrosterone sulfate (DHEAS) from 1 ml serum by reverse phase thin-layer chromatography (TLC) is described. The method comprises an isolation step of sulfated steroids by means of octadecylsilane-bonded (C18) reverse phase column chromatography, a solvolysis step for desulfation of sulfated steroids, and a C18 TLC step for measurement on a photodensitometer. This method is much simpler and more rapid than the methods previously reported, since neither a radioisotope is needed, nor any steps of saponification, derivatization, tedious scraping from a TLC plate, and time-consuming conventional column chromatography are not required. The present method allowed us to distinguish recessive X-linked ichthyosis (RXLI) very easily from ichthyosis vulgaris (IV) by the size and gradation of clearly visible blue chromogen derived from CS on a TLC plate in RXLI. By photodensitometer scanning, the CS levels in patients with RXLI were about 10 times higher than those of patients with IV and healthy subjects, whereas the DHEAS level was normal in the RXLI patients. The present simplified method proved to be useful in diagnosis of RXLI.