Clinical value of serum gamma-glutamyl transferase estimation in porphyria cutanea tarda.

Serum gamma-glutamyl transferase was elevated fourfold in all thirty-four new cases of porphyria cutanea tarda. Phlebotomy treatment decreased it. The twelve patients in relapse showed a considerable increase, while those in remission tended to a gradual elevation in the enzyme over the course of years. gamma-Glutamyl transferase is a useful auxiliary parameter in porphyria cutanea tarda particularly in untreated cases.