1. The levels of ‘X-porphyrin’, a porphyrin-peptide complex, have been studied in the faeces of patients with different types of porphyria, as well as in fifty normal subjects.
2. These levels have been shown to be significantly elevated in untreated porphyria cutanea tarda and in variegate porphyria.
3. Lesser elevations were seen in acute intermittent porphyria and hereditary coproporphyria. There was no elevation in erythropoietic protoporphyria.