Urinary excretion of porphyrins in two cases of porphyria cutanea tarda during a period of various treatments

Abstract

The urinary exrection of porphyrins in two cases of porphyria cutanea tarda (PCT) has been followed during a period in which various treatments have been tried. In one patient pyridoxal-5-phosphate (P-5-P) injections lead to a dramatic increase in porphyrin excretion. In another P-5-P treatment was followed by a significant decrease in porphyrin excretion. p-Aminobenzoic acid (PABA) apparently had no effect on porphyrin excretion, while repeated phlebotomies had the expected effect. In both patients all variations in the total amount of porphyrins excreted were almost exclusively due to the variations in the amounts of heptacarboxylic porphyrin type III and uroporphyrin I. A secondary finding was an increase in hexa- and penta-carboxylic porphyrins type III without a concomitant increase in coproporphyrin III.

Key Words:

• p-aminobenzoic acid
• coproporphyria
• phlebotomies
• porphyria cutanea tarda
• porphyrin metabolism
• pyridoxal 5-phosphate
• uroporphyria