Urinary porphyrins in liver disease.

By use of quantitative thin-layer chromatography, urinary porphyrins were examined in 40 healthy volunteers, 38 patients with prophyria cutanea tarda (PCT), and 139 patients with various liver diseases. Significant elevations not only of coproporphyrin but also of some other porphyrins were found in many patients with liver disease. However, there was no evident relationship between porphyrin disturbances and functional or clinical findings, and all of these non-PCT patients who initially demonstrated intense uroporphyrinuria, when re-studied apparently had more normal porphyrin excretion. It seems, therefore, that whereas porphyrin estimations are useful in porphyrias, no clinically important conclusions can be drawn from urinary findings in patients with liver disease. The origin of defective haem biosynthesis in liver disease remains obscure. It can only be speculated that transient and reversible urocoproporphyrinuria may occur in patients with defective hepatic uroporphyrinogen decarboxylase activity who clinically and biochemically are not porphyric.