Brain perfusion defects by SPET/CT and neurostat semi-quantitative analysis in two patients with congenital erythropoietic porphyria.

BACKGROUND: Congenital erythropoietic porphyria (CEP) is a rare autosomal recessively inherited disorder with chronic and relatively stable presentation. Till now brain blood flow derangements have been described only in acute hepatic porphyrias. We describe the first findings of brain perfusion defects, studied by single photon emission tomography/computed tomography (SPET/CT), in two patients affected by CEP, by using a semi-quantification anatomic-standardized voxel-based program compared with magnetic resonance imaging (MRI) results. SUBJECTS AND METHODS: Two Pakistanis brothers were investigated for CEP confirmed by a genetic test. The disease was severe with: skin burning, mood depression and haemolytic anemia. Considering depression, patients underwent brain SPET/CT and MRI. Single photon emission tomography/CT images were processed by neurostat semi-quantitative software. Data obtained were compared to a normal database and z-score images were generated. RESULTS: In both patients we found several perfusion defects evident in transaxial slices and in z-score images obtained by neurostat processing. Magnetic resonance imaging was negative in both patients. Biochemical mechanisms inducing localized brain hypoperfusion are uncertain. However, mismatch between SPET/CT data and MRI was probably due to absence of necrosis. CONCLUSION: In our opinion, SPET/CT could have a key role in this setting of patients due to its high sensitivity and reliability in mild-to-moderate brain perfusion defects detection. Moreover, the quantitative analysis by using neurostat may allow to recognize even mild brain perfusion alterations, difficult to detect only visually.

[Erythropoietic protoporphyria : Clinical manifestations, diagnosis and new therapeutic possibilities]. / Erythropoetische Protoporphyrie : Klinik, Diagnostik und neue therapeutische Möglichkeiten.

BACKGROUND: Erythropoietic protoporphyria, the second most common type of the cutaneous porphyrias, is due to an enzymatic deficiency of ferrochelatase, the last enzyme in heme biosynthesis. The enzyme defect leads to an accumulation of protoporphyrin IX in erythrocytes and an elevated excretion of this metabolite in the feces. CLINICAL PRESENTATION: Usually, disease onset is in early infancy, characterized by increased photosensitivity. During or shortly after sunlight exposure, affected individuals suffer from burning, stinging, itching, and pain in sun-exposed skin areas. These symptoms lead to a considerably reduced quality of life and strict avoidance of sunlight exposure. Subacute symptoms include visible changes like edema and erythema. In the further course of the disease, chronic signs such as lichenification and scarring may occur. A severe complication of hepatic protoporphyrin IX accumulation is the development of a potentially life-threatening fulminant liver failure. Therefore, hepatic laboratory tests and ultrasound of the liver should be performed regularly. THERAPY: Traditionally, therapy merely consisted of consequent photoprotection and orally administered ß-carotene. A novel treatment option is afamelanotide (Scenesse®), a synthetic analogue of the naturally occurring α-melanocyte stimulating hormone. Afamelanotide, administered as a subcutaneous implant, induces eumelanin production, independent of preceding UV light exposure. This may enable patients with erythropoietic protoporphyria to stay in sunlight significantly longer than previously possible without complaints, thus, substantially improving quality of life.

Severe osteopenia in congenital erythropoietic porphyria.

Congenital erythropoietic porphyria is a rare disorder of porphyrin metabolism. The authors describe a 15-year-old boy in whom the radiologic manifestations of this disorder included the known features of osteopenia, acro-osteolysis, soft-tissue calcifications and widening of the diploic space, as well as the previously unreported findings of severe vertebral compression fractures, thoracic kyphosis, and "salt and pepper" skull.