Guide for the classification of porphyrias using state-of-the-art reverse-phase high-performance liquid chromatography.

Abstract

The biochemical diagnosis of porphyria is based on the analysis of porphyrins in urine, feces, and blood using fluorometry and spectrometry. High-performance liquid chromatography (HPLC) with fluorescence detection has been used since the 1980s as standard procedure for separation of porphyrin isomers and classification of the different types of porphyria since each type of porphyria presents a characteristic HPLC isomer distribution either in urine, plasma or feces. We present a unified collection of chromatograms as an aid for porphyria classification in laboratories using HPLC equipment. Biological samples were collected according to approved hospital protocols, and analyzed by reverse-phase HPLC with fluorescence detection, using an unused dedicated chromatographic column BDS-Hypersil^™ C18 and reproducing, with minor variations, the conditions originally reported by Lim and Peters in 1984. With the chromatograms, we include a concise explanation of the changes observed. When inter-individual variation is frequent, we include for clarification chromatograms of two different individual samples. Additionally, we present chromatograms showing abnormalities of porphyrin metabolism in patients without porphyria. We add our collection to the literature, as a visual guide to facilitate porphyria diagnosis and classification though understanding of the key metabolic changes. Our aim is to support education of new experts in the porphyria field increasing diagnostic accuracy and ultimately leading to improved patient outcomes and management.