HEME-BIOSYNTHESIS IN CUTANEOUS HEPATIC PORPHYRIA - COMPARISON WITH ALCOHOLISM AND LIVER-DISEASE

Abstract

The enzymes of hemebiosynthesis were measured in the peripheral blood of 13 patients with cutaneous hepatic porphyria. The activity of leukocyte .delta.-aminolevulinic acid synthase was significantly elevated (P < 0.001) as was that of erythrocyte porphobilinogen deaminase (P < 0.05). Leukocyte ferrochelatase activity was depressed (P < 0.001) and the activity of erythrocyte uroporphyrinogen decarboxylase did not significantly differ from control values. Similar enzyme activities were assayed in 12 chronic alcoholics and 8 patients with liver disease and the results differed markedly from those obtained from the porphyric patients. The raised leucocyte .delta.-aminolevulinic acid synthase activity may not be attributable to alcohol ingestion or liver disease. A defect in the activity of uroporphyrinogen decarboxylase may exist in cutaneous hepatic porphyria, but this could not be demonstrated in erythrocytes.