Human protoporphyria: reduced cutaneous photosensitivity and lower erythrocyte porphyrin levels during pregnancy.
BACKGROUND
Women with erythropoietic protoporphyria (EPP) have reported increased sunlight tolerance during pregnancy. Review of clinical information in an existing database for an EPP population study found five women who had six pregnancies while enrolled. All had experienced attenuated photosensitivity during gestation.


OBJECTIVE
Our purpose was to gain insight into whether altered porphyrin metabolism during pregnancy might explain this phenomenon.


METHODS
Erythrocyte protoporphyrin levels obtained for these women during six periods of gestation were compared with data accumulated over the course of several years during nongestational periods.


RESULTS
Erythrocyte porphyrin levels were lower during pregnancy. The differences of the means for values obtained during nongestational periods versus values obtained during pregnancy for each woman were found to reach or approach significance (p < 0.05) by a paired t test when analyzed without regard for seasonality (p = 0.042) or when adjusted for possible seasonal effects of sunlight on erythrocyte porphyrin levels by separation into data sets for low sunlight months (October-April) (p = 0.039) or high sunlight months (May-September) (p = 0.057).


CONCLUSIONS
These observations suggest that a beneficial physiologic effect of pregnancy in patients with EPP may be a lower circulating erythrocyte protoporphyrin burden that leads to reduced photosensitivity.
Poh-Fitzpatrick
M B
MB
Department of Dermatology, Columbia University College of Physicians and Surgeons, St. Luke's-Roosevelt Hospital Center, New York, NY 10019, USA.
D000328:Adult; D004912:Erythrocytes / Q000378:metabolism*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007256:Information Systems; D008137:Longitudinal Studies; D010787:Photosensitivity Disorders / Q000097:blood / Q000378:metabolism / Q000503:physiopathology*; D017121:Porphyria, Hepatoerythropoietic / Q000097:blood / Q000378:metabolism / Q000503:physiopathology*; D011166:Porphyrins / Q000097:blood* / Q000378:metabolism; D011247:Pregnancy; D011248:Pregnancy Complications / Q000097:blood / Q000378:metabolism / Q000503:physiopathology*; D011524:Protoporphyrins / Q000097:blood / Q000378:metabolism; D012621:Seasons; D013472:Sunlight
D011166:Porphyrins; D011524:Protoporphyrins