抄録
Two unrelated patients with erythropoietic protoporphyria (EPP) were studied. Patient R. A. was a 10-year-old girl and patient S. O. was a 51-year-old man.
Diagnosis of EPP was established in both patients by a history of photosensitivity on exposed areas of the skin since childhood and by marked increase of protoporphyrin levels in erythrocytes, plasma and feces.
Heme synthetase activity in erythroblasts was remarkably decreased in both patients, 1.2 and 1.3mμ moles hemin formed/120min./108 erythroblasts, as compared with control values (range 2.5∼6.4; n=5). This metabolic abnormality provided one biochemical explanation for the increased level of erythrocyte protoporphyrin in EPP.
Subnormal levels of Hb without sideropenia were observed in both patients. Ringed sideroblasts were found in 1 and 8%, respectively and by transmission electron microscopy iron deposits in the cristae of mitochondria in erythroblasts were observed, although the ferrokinetic study in patient S. O. was within normal limits.
In patient S. O., the liver was palpable three fingers breadth on admission and intermittent elevations in serum GOT, GPT and γGTP levels were observed. A percutaneous liver biopsy specimen revealed the feature of non-specific chronic hepatitis. Furthermore in frozen, unfixed sections of the liver, brilliant red fluorescence showing the presence of protoporphyrin was evident in a part of hepatocytes and Kupffer cells. After 4 years, he died of hepatic cirrhosis with severe jaundice and hepatic failure.
The oral administration of 15 to 30mg/day of β-carotene was safe and effective for ameliorating the photosensitivity in both patients.
