Exploiting sterol profile analysis: Over ten years of experience. A narrative review

The analysis of sterol profile consists in the qualitative and quantitative determination of cholesterol and non-cholesterol sterols. Non-cholesterol sterols include the cholesterol precursors in de novo biosynthesis pathway, cholesterol catabolites and plant sterols absorbed from diet. The sterol profile analysis can be performed on different biological matrices, i.e., plasma/serum, whole blood, erythrocyte membranes, tissues and cells, depending on the clinical and/or experimental purpose. The reference method for the sterol profile analysis is the gas-chromatography coupled with mass spectrometry, although new methods based on liquid-chromatography or direct mass spectrometry have been developed. The sterol profile analysis represents a fundamental tool for the biochemical diagnosis of the congenital defects of cholesterol metabolism. In addition, some non-cholesterol sterols have been validated as surrogate markers of de novo synthesis and intestinal absorption of cholesterol. Therefore, the sterol profile analysis has been used for the evaluation of cholesterol homeostasis in different diseases. This review focuses on these applications and our clinical and experimental findings. In the last nine years, we identified 18 new cases of the cholesterol metabolism defects and we found that cholesterol metabolism is impaired in patients with cystic fibrosis.