A simple and fast HPLC method for the determination of
porphyrins in bile without extraction is described.
Porphyrins were determined in bile from control subjects and from patients after orthotopic
liver transplantation, including three patients with
erythropoietic protoporphyria. It was found that: 1)
coproporphyrin I is the predominant
porphyrin in bile of controls, accompanied by some
coproporphyrin III and
protoporphyrin, whereas
protoporphyrin mostly but not always is the predominant
porphyrin in the bile of
erythropoietic protoporphyria patients. In two of the three
erythropoietic protoporphyria patients, the bile contained a hundred times more
protoporphyrin than that of non-porphyric orthotopic
liver transplantation patients. The third
erythropoietic protoporphyria patient remained cholestatic and was unable to excrete sufficient amounts of
protoporphyrin. 2) All investigated bile samples contained no secondary
porphyrins derived from
protoporphyrin, i.e. no deutero-, pempto-, or
mesoporphyrin. Even when extracts of bile and serum were concentrated fifty to a hundred times, no traces of deutero-, pempto- and
mesoporphyrin were detected. This complete absence of secondary
porphyrins suggests that an enterohepatic circulation of dicarboxylic
porphyrins from the distal gastrointestinal tract does not exist. 3) The HPLC chromatograms contain peaks from unknown compounds. No correlation between
porphyrins and these compounds was found.
Porphyrin profiles were followed in the bile of some orthotopic
liver transplantation patients. Three episodes are recognizable. During the first three days after orthotopic
liver transplantation there is a very high coproporphyrin excretion. There is then a lag of one to three weeks, in which no or very low
porphyrin concentrations are detectable, followed by the restoration of normal biliary
porphyrin patterns.