[Diagnosis and therapy of hepatic porphyria]

The term porphyria includes a heterogeneous group of metabolic diseases, which are genetically determined and usually require a "gene-environment interaction" for clinical manifestation of the genetic disposition. Molecular cause for a porphyria is a defective enzyme in the chain of heme biosynthesis. Generally, one differentiates between erythropoietic and hepatic porphyrias. From the clinical point of view, a classification into potentially acute and non-acute forms is of value. Abdominal-neurologic-cardiovascular symptoms dominate the syndromes of intermittently occurring acute hepatic porphyrias, while cutaneous symptoms are related to non-acute, chronic hepatic porphyrias. A combination of the symptoms may occur in porphyria variegata and hereditary coproporphyria. Courses with hepatobiliary involvement are not seldom found in protoporphyria. Only in genuine porphyrias the clinical symptoms can be explained by the pathophysiological consequences of a disturbance in porphyrin metabolism, not, however, in cases of the common secondary porphyrinopathia. The latter porphyrinuria, in contrast to hepatic porphyrias, must be seen as metabolic symptom of another basic disease. Secondary hepatic coproporphyria by itself has no independent and clinical qualities of a disease. The differentiation of hepatic porphyrias into their different classes and enzymologic types, their recognition during latent phases and, especially, their distinction from secondary coproporphyrinurias requires a complex pathobiochemical evaluation with integration of anamnesis and clinical findings.