Porphyrin studies in chronic renal failure patients on maintenance hemodialysis.

Porphyrin studies were performed on 85 chronic renal failure patients on maintenance hemodialysis. Free erythrocyte porphyrins were elevated in 70% of patients, and a significant positive correlation between erythrocyte porphyrin and serum aluminium was found. Although plasma porphyrins were elevated in 58% of our patients, the elevated heptacarboxylic fraction invariably seen in porphyria cutanea tarda (PCT) was not present in the hemodialyzed patients. Total urine and fecal porphyrins were low, due to a marked decrease in the coproporphyrin and dicarboxylic fractions, respectively. An unequivocal diagnosis of PCT was made in 1 hemodialysis patient whose biochemical findings included an extremely high total plasma porphyrin with a large heptacarboxyl-porphyrin fraction. We found no biochemical evidence for any trend towards PCT in the remaining hemodialysis patients. The porphyrin results on a subgroup of hemodialysis patients with blisters or a history of blisters on sun-exposed skin were similar to those of the hemodialysis patients without blisters.