The prognostic value of cord blood analysis in erythropoietic protoporphyria: the 'Duesseldorf Cord Blood Study'

Background: Erythropoietic protoporphyria (EPP) is the most common porphyria in childhood, presenting with painful and burning skin sensations as well as erythema and edema after sun exposure. It represents an inherited disorder of heme metabolism that is due to a reduced ferrochelatase enzyme activity. The diagnosis is usually established when symptoms start by measuring elevated levels of protoporphyrin in erythrocytes. The aim of our study was to question the predictive value of cord blood analysis in newborn relatives of EPP patients as this may offer the earliest possible diagnosis of EPP in newborn relatives of affected patients.
Methods: Erythrocyte porphyrin (EP) was measured immediately after birth in 18 newborn relatives of EPP patients. EP was correlated to the subsequent clinical follow-up of mean 9 years after birth.
Results: We found EP to be within reference values in all 18 newborn relatives of EPP patients at birth. Out of 14 patients who were included in the follow-up period of median 9 years, 13 remained asymptomatic whereas one boy developed the typical symptoms of EPP at the age of three in combination with elevated EP.
Conclusion: Based on the findings of our study, we assume that cord blood analysis is not a reliable prognostic tool in EPP from the actual point of view.