[Therapeutic and pathogenetic aspects of porphyria cutanea tarda]

Seventy-three patients with porphyria cutanea tarda (PCT) were treated with chloroquine phosphate, which was administered in doses of 250 mg twice a week for more than 1 year on average. Of these patient, 49% did not have any associated ("inducing") factors. After treatment, serum transaminases and gamma-glutamyltransferase (gamma-GT) always returned to normal values. However, gamma-GT did not reach the normal range in the group without associated factors ("idiopathic group"). Of the 66 patients studied, 25 achieved an approximately physiological distribution of the pattern of urinary porphyrin fractions. Control biopsies were performed in 66 patients. Of them, 48 patients showed an improvement in liver damage. A statistically significant correlation was observed between a lasting increase in urinary prophyrin content and unchanged pathological liver morphology. A pathogenesis concept for PCT is discussed as a disease between inheritance (genetic enzyme defect) and environment ("inducing factors"). Even in the "idiopathic group" the improvement of pathological liver changes after therapeutic removal of the pathological prophyrin content in the liver cells shows that porphyrins could also cause liver damage.