[Protoporphyrinemia and iron metabolism in hemodialysis patients]. 
In 24 patients undergoing haemodialysis, two of them with pseudoporphyria, the total erythrocytic protoporphyrin and in four patients separately the zinc protoporphyrin were investigated.  20 patients showed an increase of the erythrocytic protoporphyrin of low to moderate degree, which only partly is to be ascribed to the zinc protoporphyrin.  Since, as a rule, there is no iron deficit in haemodialysis, a secondary damage of the ferrochelatase, which physiologically by administration of iron leads to haem (ferroprotoporphyrin), is assumed as cause of the increase of erythrocytic protoporphyrin.  Apart from the toxic lesion in particular a deficiency of the ferrochelatase coenzyme pyridoxal phosphate can be taken into consideration.  Diagnostic and therapeutic investigations carrying on are proposed.  The erythrocytic protoporphyrin does not only contribute to the pseudoporphyria in haemodialysis.