- First morning void or 24-hour urine collection
- Chromatography uniquely separates three precoproporphyrins and coproporphyrins I and III
- Pre coproporphyrins reported separately and total precoproporphyrins expressed per uroporphyrins
Porphyrins vs Pyrroles?
- A porphyrin is usually made up of 4 pyrroles, (pyrroles making up the basic sub-unit of porphyrins).
- Kryptopyrrole testing looks for pyroluria (high pyrroles in the urine).
- Porphyrin testing looks for various ‘porphyrias’ (high porphyrins in the urine)
Differences between Krytopyrrole test and Urine Porphyrins test:
- Kryptopyrrole Test
- Only looks at pyrroles
- Urine Porphyrins Test
- Looks at entire heme metabolism cascade
Urinary porphyrins are intermediary metabolites of heme biosynthesis and can serve as biomarkers of certain disorders in heme production and toxic burden. Heme is incorporated into becoming Hemoglobin protein (the oxygen carrying molecule in the blood) but also is essential in supporting energy production via the electron transport chain and liver detox. Heme biosynthesis begins with the formation of alpha-aminolevulonic acid from succinyl-CoA and glycine with pyridoxal-5-phosphate as an obligatory co-factor. Thereafter, a series of enzymatic and non-enzymatic reactions produce various porphyrins and Heme.