Utility of plasma fluorometric emission scanning for diagnosis of the first 2 cases reports of variegate porphyria: a very rare type of porphyrias in Thai

Two Thai women who are siblings presented with a history of recurrent pruritic vesicles on dorsum of both hands and extensor surface of forearms where the sun-exposed areas are. The excoriated vesicles were healed with depressed scars. They had no previous history of intense abdominal pain, seizure, or psychiatric disorder Urinary porphyrins were analyzed by High Performance Liquid Chromatography (HPLC). The level of coproporphyrin III was detected to be higher than the uroporphyrin level. Fluorescence emission scanning of both patients' plasma was performed and demonstrated typical emission peak at 626 nm, that confirmed the diagnosis of variegate porphyria.

Effect of an oral iron chelator or iron-deficient diets on uroporphyria in a murine model of porphyria cutanea tarda

Porphyria cutanea tarda is a liver disease characterized by elevated hepatic iron and excessive production of uroporphyrin (URO). Phlebotomy is an effective treatment that probably acts by reducing hepatic iron. Here we used Hfe(-/-) mice to compare the effects on hepatic URO accumulation of two different methods of hepatic iron depletion: iron chelation using deferiprone (L1) versus iron-deficient diets. Hfe(-/-) mice in a 129S6/SvEvTac background were fed 5-aminolevulinic acid (ALA), which results in hepatic URO accumulation, and increasing doses of L1 in the drinking water. Hepatic URO accumulation was completely prevented at low L1 doses, which partially depleted hepatic nonheme iron. By histological assessment, the decrease in hepatic URO accumulation was associated with greater depletion of iron from hepatocytes than from Kupffer cells. The L1 treatment had no effect on levels of hepatic cytochrome P4501A2 (CYP1A2). L1 also effectively decreased hepatic URO accumulation in C57BL/6 Hfe(-/-) mice treated with ALA and a CYP1A2 inducer. ALA-treated mice maintained on defined iron-deficient diets, rather than chow diets, did not develop uroporphyria, even when the animals were iron-supplemented either directly in the diet or by iron dextran injection.

CONCLUSION

The results suggest that dietary factors other than iron are involved in the development of uroporphyria and that a modest depletion of hepatocyte iron by L1 is sufficient to prevent URO accumulation.

High-performance liquid chromatography/electrospray ionization tandem mass spectrometry of hydroxylated uroporphyrin and urochlorin derivatives formed by photochemical oxidation of uroporphyrinogen I

Hydroxylated uroporphyrin I and urochlorin I derivatives formed by photochemical oxidation of uroporphyrinogen I were separated by high-performance liquid chromatography and fully characterized by electrospray ionization tandem mass spectrometry. The porphyrins and chlorins were identified by analysis of their product ion spectra with each hydroxylated derivative giving a characteristic collision-induced dissociation fragmentation pattern. The porphyrins and chlorins characterized were meso-hydroxyuroporphyrin I, alpha-hydroxypropionic acid uroporphyrin I, beta-hydroxypropionic acid uroporphyrin I, hydroxyacetic acid uroporphyrin I, trans-7-hydroxy-8-spirolactoneurochlorin I, cis-7-hydroxy-8-spirolactoneurochlorin I and trans- and cis-7,8-dihydroxyurochlorins I.

Diagnostic traps in porphyria: case report and literature review

Porphyrias are metabolic disorders of heme biosynthesis, which encompass a broad range of symptoms and signs, neurologic, cutaneous or mixed. Because of lack of specificity and polymorphous clinical picture, porphyrias can mimic either neuropsychiatric, dermatologic, or gastrointestinal diseases. We present the case of a 58 years old man to whom clinical presentation suspicious of Addison's disease (melanoderma, fatigue, weight loss, intermittent abdominal pain) was the disguise of porphyria cutanea tarda. A general background of porphyrias and differential diagnosis with other forms of hepatic porphyria, as well as other causes of hyperpigmentation, are given. The clinician should be aware of the protean manifestations of porphyrias and include them in clinical judgment in various situations.

Congenital erythropoietic porphyria (Günther's disease): two cases with very early prenatal manifestation and cystic hygroma

Congenital erythropoietic porphyria (CEP) or Günther's disease is the rarest form of the porphyrias. The disease is usually diagnosed at birth or during early infancy, but rarely in utero. We describe here the first two cases of very early prenatal expression of CEP with cystic hygroma diagnosed at 14 weeks in the first fetus and at 19 weeks in the second. Both fetuses presented with severe nonimmune hydrops fetalis as early as 19 and 22 weeks, associated with intrauterine growth retardation, hyperechogenic kidneys and bones. Amniotic fluid was dark brown and uro- and coproporphyrin I was dramatically increased. Molecular screening of the CEP gene detected heterozygous C73R mutation in both fetuses, the other parental mutation being as yet unknown.

Hereditary coproporphyria in Germany: clinical-biochemical studies in 53 patients

OBJECTIVES

To describe the biochemical and clinical features in hereditary coproporphyria (HCP).

DESIGN AND METHOD

Within the last 20 years, we investigated 53 patients (male:female = 1:2.5; age = 8-86 years) suffering from HCP. We describe the characteristic levels of urine, and fecal porphyrins and their precursors in hereditary coproporphyria and present the clinical features. Especially, we measured the coproporphyrin isomers I and III.

RESULTS AND CONCLUSION

The group of hereditary coproporphyria patients exhibited a significantly higher (p<0.0001) excretion of urinary porphyrin precursors, delta-aminolevulinic acid (median = 84 micromol/24 h) and porphobilinogen (median = 39 micromol/24 h), as compared to controls (delta-aminolevulinic acid: 22 micromol/24 h, porphobilinogen: 3 micromol/24 h; median, n = 20). The median of coproporphyrin in urine (1315 nmol/24 h) and feces (1855 nmol/g) were enhanced 12- and 168-fold, as compared to healthy subjects (urinary coproporphyrin: 106 nmol/24 h, fecal coproporphyrin: 11 nmol/g; median, n = 20). During therapy on one female patient, with IV application of heme arginate, a considerable decline of porphyrin precursors and porphyrin excretion was observed. The examination of urinary and fecal coproporphyrin isomers I and III revealed an excessive elevation of the coproporphyrin isomer III of 87% in urine and 94% in feces, respectively (normal: urinary isomer III = 69-83% and fecal isomer III = 25-40%). In feces the increase of isomer III caused an inversion of the physiologic coproporphyrin isomer III:I ratio that could be recognized in all various stages in hereditary coproporphyria and in children. Acute attacks of hereditary coproporphyria are accompanied by an acute polysymptomatic clinical syndrome, and this is associated with high levels of urinary porphyrin precursors. On review of our patients, the highest percentage had abdominal pain (89%), followed by neurologic (33%), psychiatric (28%), cardiovascular (25%), and skin symptoms (14%).

Arsenite alters heme synthesis in long-term cultures of adult rat hepatocytes

Arsenite (As[III]) effects on the intermediate steps of heme biosynthesis were studied in adult rat hepatocytes seeded on a feeder layer of 3T3 cells (3T3-hepatocytes) and maintained for 2 weeks with culture medium non-supplemented or supplemented with 150 microM 5-aminolevulinic acid (ALA). The activities of the intracellular enzymes porphobilinogen deaminase (PBG-D), uroporphyrinogen III synthase (UROIII-S), and uroporphyrinogen III decarboxylase (URO-D), and the intermediary uroporphyrins (URO), coproporphyrins (COPRO) and protoporphyrin IX (PROTO) were determined in these cultures. The 3T3-hepatocytes maintained the activities of PBG-D, UROIII-S and URO-D during 2 weeks and ALA addition to the culture medium increased PBG-D (2-3-fold) and UROIII-S (50%) activities and porphyrin production, which accumulated as PROTO. Exposure to 3.9 microM As(III) inhibited UROIII-S activity (down to 34%), and PBG-D and URO-D activities to a lower extent; these effects were magnified by ALA supplementation. As(III) also produced an intracellular accumulation and a decreased excretion of PROTO, and a 31% reduction of the COPRO/URO ratio in the culture medium. Additionally, As(III) caused cytoplasmic vacuolization and lipid accumulation. Our results show that As(III) exposure selectively inhibits several intermediary enzymes of heme metabolism and affects the intra- and extracellular content of porphyrins and their ratio in the culture medium. They also confirm that 3T3-hepatocytes are a suitable in vitro model to study hepatic heme metabolism and its alterations by hepatotoxic chemicals.

Congenital erythropoietic porphyria

Congenital erythropoietic porphyria is a rare autosomal-recessive disorder of the porphyrin metabolism caused by the homozygous defect of uroporphyrinogen III cosynthase. High amounts of uroporphyrin I accumulate in all cells and tissues, reflected by an increased erythrocyte porphyrin concentration and excretion of high porphyrin amounts in urine and feces. Dermal deposits of uroporphyrin frequently induce a dramatic phototoxic oxygen-dependent skin damage with extensive ulcerations and mutilations. Splenomegaly and hemolytic anemia are typical internal symptoms. Skeletal changes such as osteolysis and calcifications are frequent. To date 130 cases of congenital erythropoietic porphyria have been published and are summarized here. Splenectomy, erythrocyte transfusions, and bone marrow transplantation have shown some beneficial effect. The best therapy is the avoidance of sunlight. In the two patients with congenital erythropoietic porphyria described here, oral administration of the oxygen quenchers ascorbic acid and alpha-tocopherol resulted in an improvement in the reduced hemoglobin and erythrocyte concentrations.

A modified spectrophotometric assay for porphobilinogen deaminase: its application in the detection of both carriers and patients with acute intermittent porphyria

A spectrophotometric method for porphobilinogen deaminase assay in erythrocytes is described. This test is determinant for the definite diagnosis of acute intermittent porphyria. In the method described, delta-aminolevulinic acid is used as substrate. Mercaptoethanol and zinc ions are introduced to maintain delta-aminolevulinic acid dehydratase in optimal conditions and to guarantee the in vitro production of porphobilinogen. An incubation temperature of 45 degrees C leads to the production of uroporphyrins, which are measured spectrophotometrically at 405 nm, giving reproducible results. The assay can be performed easily in any clinical laboratory and is valuable for detecting both patients and carriers of acute intermittent porphyria.

Resonance Raman study of sirohydrochlorin and siroheme in sulfite reductases from sulfate reducing bacteria

Soret-excited resonance Raman (RR) spectra are reported for the sirohemes in the oxidized and Cr11(EDTA)-reduced forms of both desulforubidin from D. baculatus (DSR) and the low molecular weight sulfite reductase from D. vulgaris (1SIR) and for sirohydrochlorin in the oxidized form of desulfoviridin from D. gigas (DSV). Several patterns in the RR spectra of these enzymes can be utilized as signatures for the siroheme/sirohydrochlorin moiety. The active site for DSR and 1SIR consists of a siroheme exchange-coupled to a [4Fe-4S]2+ cluster. Upon addition of Cr11(EDTA), the active center of DSR and 1SIR undergoes a one-electron and two-electron reduction, respectively. The RR spectra of DSR suggest that the siroheme iron is high spin and 5-coordinate in the oxidized enzyme and probably remains high spin and 5-coordinate upon reduction. The iron in the siroheme of oxidized 1SIR changes from a low spin and probably 6-coordinate configuration to a high spin, 5-coordinate complex upon two-electron reduction of the active site. Close similarities between the RR spectral features of the two-electron-reduced assimilatory sulfite reductases from E. coli and from D. vulgaris (1SIR) are discussed.

The role of iron in experimental porphyria and porphyria cutanea tarda

Porphyria cutanea tarda (PCT) and experimental porphyria are characterized by a decreased activity of the enzyme uroporphyrinogen decarboxylase, and accumulation of uroporphyrins and heptacarboxylporphyrins in the liver. Iron (Fe) plays an important role in PCT and experimental porphyria. Biochemically and electron microscopically, we examined the relationship between Fe and porphyrins in liver tissue of C57BL/10 mice made porphyric by administration of iron dextran as Imferon (IMF), and in liver biopsies of patients with symptomatic PCT. Accumulation of uroporphyrins and heptacarboxylporphyrins, and an increased amount of Fe were observed in livers of mice treated with IMF and in liver biopsies of patients with PCT. In mice treated with IMF, the activity of uroporphyrinogen decarboxylase was decreased. Both in livers of mice treated with IMF and in livers of patients with PCT, needle-like structures, representing uroporphyrin crystals, were observed by electron microscopy. Uroporphyrin crystals and Fe (as ferritin) were observed in the same hepatocyte. Moreover, there was a striking morphological correlation between uroporphyrin crystals and ferritin-Fe, suggesting a role for (ferritin-)Fe in the pathogenesis of porphyria.

Preparation, high-performance liquid chromatographic separation and characterization of hexacarboxylic porphyrinogens

A simple method for the preparation and reversed-phase high-performance liquid chromatographic separation of hexacarboxylic porphyrinogen isomers is described. Uroporphyrin I or III was partially decarboxylated in 0.5 M hydrochloric acid at 150 degrees C. Unreacted uroporphyrin and the hepta-, hexa- and pentacarboxylic porphyrins formed were esterified and then group-separated by thin-layer chromatography. After hydrolysis, the porphyrins were reduced to the corresponding porphyrinogens with 3% (w/w) sodium amalgam. The hexacarboxylic porphyrinogens were separated on an ODS-Hypersil column by elution with acetonitrile-methanol-1 M ammonium acetate, pH 5.16 (8:12:80, v/v/v) as mobile phase. Isomers were identified by high-performance liquid chromatography of the characteristic mixture of two pentacarboxylic porphyrins formed after partial decarboxylation of individual isomers. Except for the two type I isomers, resolution of the hexacarboxylic porphyrinogens was superior to that of the corresponding porphyrins.

Factors influencing fluorescence spectra of free porphyrins

We recorded fluorescence excitation and emission spectra of uro- and coproporphyrin under different experimental conditions, to see how these conditions influence quantifications based on measurement of fluorescence intensity. We found that, for bands alpha and beta of the emission spectra and the main peak of the excitation spectra, fluorescence depends on pH and is minimal near pH 5 and near pH 7-7.5 for copro- and uroporphyrin, respectively. For band gamma of the emission spectra there was a constant decrease of fluorescence with increasing alkalinity of the solution. The intensity of porphyrin fluorescence also depends on ionic strength, reaching sharp maxima at 0.1 mol/L (for uroporphyrin) and 1 mol/L (for coproporphyrin). The organic mixture ethyl acetate:acetic acid (4:1 by vol), commonly used to extract porphyrins from biological samples, markedly diminishes the fluorescence of both porphyrins as compared with the same concentration of each porphyrin in aqueous acidic solvent. Furthermore, when we measured different ratios of uro:copro mixture at three distinct pHs and buffers, we found that at pH 10.5 (in carbonate buffer) the measured units of fluorescence depend only on total porphyrin concentration and not on the composition of the mixture.

Homozygous variegate porphyria. A severe skin disease of infancy

A boy exhibited severe bullous skin disease a few days after birth, followed by increased fragility of the exposed skin in spring and summer. Examination at 2 1/2 years of age led to characteristic biochemical findings: increased excretion of fecal porphyrins (coproporphyrin 121 to 131 and protoporphyrin 467 to 576 nmol/g dry weight), and increased erythrocyte protoporphyrin concentration (3643 to 4840 nmol/l). Lymphocyte protoporphyrinogen oxidase activity was very low in the patient (0.4 nmol/mg protein/h) and half-normal (2.7 and 2.3 nmol/mg protein/h) in the parents, suggesting that the patient had homozygous variegate porphyria. Severe skin symptoms and a high concentration of red cell protoporphyrin concentration in an infant should prompt suspicion of homozygous acute hepatic porphyria.

An internal standard for porphyrin analysis

The routine clinical analysis of the porphyrin precursors of heme requires an internal standard to determine the efficiency of the analytical procedure used. 2-Vinyl-4-hydroxymethyldeuteroporphyrin IX has been prepared as an internal standard. Its application to porphyrin analysis has been demonstrated using high-performance liquid chromatographic resolution of the uro- to protoporphyrins in normal and porphyric urine.

Pseudoporphyria associated with consumption of brewers' yeast

A case of pseudoporphyria associated with excessive consumption of brewers ' yeast was studied. Detailed analysis of the yeast tablets by high performance liquid chromatography showed the presence of dicarboxylic deuteroporphyrin , mesoporphyrin, and protoporphyrin; coproporphyrin I and III isomers; and uroporphyrin I and III isomers. The faecal porphyrin concentration of the patient taking yeast tablets was significantly increased, resembling the excretion pattern in variegate porphyria. Any patient showing an unusual porphyrin excretion pattern on high performance liquid chromatography should be investigated for a possible dietary cause.

Urine and faecal porphyrin profiles by reversed-phase high-performance liquid chromatography in the porphyrias

A novel reversed-phase system is described for the simultaneous separation of type I and type III isomers of uro-, heptacarboxylic-, hexacarboxylic -, pentacarboxylic - and copro -porphyrins and the dicarboxylic meso- and proto-porphyrins. The porphyrins were resolved on a Hypersil -SAS column eluted with 10% (v/v) acetonitrile in 1 mol/l ammonium acetate, pH 5.16 (solvent A) and 10% (v/v) acetonitrile in methanol (solvent B) with a linear gradient from 100% A (0%B) to 35% A (65%B) in 30 min followed by isocratic elution at 65% B for a further 10 min. The method is simple and reproducible and has been applied to the analysis of porphyrins in urine and faeces from patients with acute intermittent, variegate, hereditary copro , congenital erythropoietic, erythrohepatic proto and symptomatic porphyrias.

Rapid semiquantitative measurement of total porphyrins in urine and feces by magnetic circular dichroism

Magnetic circular dichroism is a suitable technique for semiquantitative determination of total porphyrins in urine and feces, being rapid, reliable, and involving little sample preparation. The sensitivity of the assay suffices to distinguish normal from above-normal concentrations of total porphyrins in urine and feces. Results for urine compare well with those obtained by thin-layer chromatography of porphyrin esters (n = 42, r = 0.92) or ion-exchange column chromatography of porphyrin acids (n = 19, r = 0.80).

Uroporphyrinogen III cosynthetase: a direct assay method

The activity of uroporphyrinogen III cosynthetase may be determined in a direct assay system in which preuroporphyrinogen is generated from porphobilinogen by the action of porphobilinogen deaminase. The basis of the assay relies on the much faster enzymatic conversion of preuroporphyrinogen into uroporphyrinogen III by cosynthetase compared with the non-enzymic decomposition of preuroporphyrinogen into uroporphyrinogen I. The amount of porphyrinogen (measured as porphyrins) formed from porphobilinogen in the presence of the cosynthetase, after subtraction of the porphyrin formed with deaminase alone, gives a direct assessment of the uroporphyrinogen III and therefore of the cosynthetase activity. The assay may be utilized for the determination of pure cosynthetases and for cosynthetases in crude systems such as whole blood haemolysates or liver homogenates. The assay can be accomplished in a fraction of the time required for previous methods.

Porphyrins in renal transplantation

The porphyrin status of 38 renal transplant patients was investigated using a sensitive thin-layer chromatographic assay. Abnormalities of porphyrin synthesis observed in patients on hemodialysis were generally reversed on receipt of a transplant with sustained good renal function. Urinary coproporphyrin levels and the creatinine clearance appeared directly related in both individual cases and generally, substantiating the theory that coproporphyrin is of renal origin. The pre- and postoperative porphyrin status of a unique patient with variegate porphyria who received a successful renal transplant implies that the excess urinary porphyrins and precursors excreted in the acute porphyrias are also of mainly renal, as opposed to hepatic origin. Furthermore, the posttransplant overproduction of porphyrins by a kidney from a normal donor suggests the existence of an endogenous porphyrogenic agent in the circulation of patients with acute porphyria.

The effects of canthaxanthin on the photocutaneous manifestations of porphyria

An open trial with canthaxanthin, a photoprotective agent, was carried out on 7 patients with erythrohepatic protoporphyria (EHP), 5 patients with variegate porphyria (VP), and 2 patients with symptomatic porphyria (SP). In 4 of the 7 patients with EHP, sun tolerance was significantly but only moderately increased. In 2 children sun tolerance was greatly increased. Only 2 of the 5 patients with VP and 1 of the 2 patients with SP showed any improvement.

The use of the rat in the experimental investigation of the porphyrias

The patterns of urinary porphyria excretion and hepatic porphyrin accumulation in hexachlorobenzene-treated rats is similar to that observed in overt porphyria cutanea tarda and may be attributed to a decrease in activity of hepatic uroporphyrinogen (UROGEN) decarboxylase. The 3.5 diethoxycarbonyl-1,4-dihydrocollidine (DDC)-treated rat has been evaluated as a model to test the porphyrinogenicity of drugs.

[Premature cutaneous porphyria caused by oral contraceptives (author's transl)]

Four women, aged 23 to 26 years, fell ill with cutaneous hepatic porphyria. All of them had taken oestrogen-contaning oral contraceptives three to eight years before the illness. In one instance there was a time relationship with a progestogen preparation. The clinical and biochemical signs were those of porphyria cutanea tarda, but contrary to this disease there was a shift towards heptacarboxyporphyrin in the uroporphyrin/heptacarboxyporphyrin ratio (thin-layer chromatography, classified according to Doss). This difference and the onset at an early age suggest that the described disease may be called a hormone-induced premature cutaneous porphyria.

Total plasma porphyrins in renal disease

Thirty patients suffering from chronic kidney disease were examined for urinary, fecal and total plasma porphyrins. Twenty patients had nitrogen retention whereas the remaining ten patients displayed normal values. Urinary coproporphyrin excretion and total plasma porphyrin levels were comparatively less pronounced in patients with nitrogen retention. Such changes in porphyrin metabolism could be explained by a diminished capacity for kidney excretion. It is concluded that the total amount of porphyrins synthesized in the body is decreased as a result of nitrogen retention.

[Porphyria variegata (author's transl)]

Porphyria variegata, one of the rarer forms of hepatic porphyria, is brought to the attention through presentation of one case. Its clinical and chemical laboratory characteristics are compared with other hepatic porphyrias and pathogenesis, hereditary transmission and therapy are gone into.