Acylcarnitine C18-OH Unit Converter

Acylcarnitine C18-OH (3-hydroxystearoylcarnitine) is a long-chain hydroxylated acylcarnitine. It is formed when the 18-carbon fatty acid stearic acid undergoes incomplete beta-oxidation in the mitochondria, producing a 3-hydroxy intermediate that is then conjugated to carnitine.

Under normal conditions, this intermediate is rapidly processed and remains at very low or undetectable levels in the blood. When specific enzymes in the long-chain fatty acid oxidation pathway are deficient, C18-OH accumulates and enters the bloodstream where it can be measured.

C18-OH is measured as part of the acylcarnitine panel and is most relevant in newborn screening and the diagnosis of fatty acid oxidation disorders.

Produced in the mitochondria during beta-oxidation of long-chain fatty acids, specifically at the step catalyzed by long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD), which is part of the mitochondrial trifunctional protein complex.