Epidemiology of cutaneous porphyria in Israel: a nationwide cohort study.

BACKGROUND: From a dermatologist's perspective, there are four major types of cutaneous porphyrias (CPs): porphyria cutanea tarda (PCT), erythropoietic protoporphyria (EPP), variegate porphyria (VP) and hereditary coproporphyria (HCP). Scarce data are available regarding the epidemiology of CPs. OBJECTIVES: To describe the epidemiology of CPs in Israel, including distribution, incidence and prevalence rates of major types. METHODS: This retrospective study includes all patients who were diagnosed with CPs between the years 1988-2018. It is based on data from Israel's National Service for the Biochemical Diagnoses of Porphyrias, and Israeli patients' nationwide electronic medical charts. Incidence and prevalence rates were calculated. RESULTS: Of 173 patients with CPs diagnosed during a 30-year period, 65 (38%) had VP, 62 (36%) had PCT, 31 (18%) had HCP and 15 (9%) had EPP; with incidence rates of 0.29, 0.30, 0.17, 0.07, and prevalence rates of 6.3, 4.8, 2.9, 1.6, respectively, per million population. Characteristics of patients with PCT differed from those with other CPs with regard to lack of family history, older mean age at diagnosis [51 vs. 36 (VP), 35 (HCP) and 25 (EPP) years] and male predominance (81% vs. similar distribution). All patients with PCT were diagnosed at adulthood, while 20%, 19% and 15% of patients with VP, HCP and EPP, respectively, were diagnosed during childhood or adolescence. CONCLUSIONS: Variegate porphyria and PCT were found to be the most prevalent in Israel; however, CPs might be underdiagnosed, thus dermatologists' awareness of these rare disorders is highly important.

A homoallelic FECH mutation in a patient with both erythropoietic protoporphyria and palmar keratoderma.

BACKGROUND: Erythropoietic protoporphyria (EPP) is a hereditary disorder caused by the deficiency of ferrochelatase (FECH) in the haem biosynthetic pathway. In the majority of families, EPP is transmitted as a pseudodominant trait. Autosomal recessive form of EPP is found in only about 3% of the families. OBJECTIVES: In this study, we describe a 6-year-old boy who suffered from both EPP and palmar keratoderma. METHODS AND RESULTS: A novel homoallelic missense mutation (p.Ser318Tyr) was identified in the FECH gene. In addition, a region of homozygosity of approximately 6.8 Mb was observed in chromosome 18 of the patient by both microsatellite and SNP array. The parents of the patient, both of Palestinian (Jordanian) origin, were heterozygous for the S318Y mutation, although no history of consanguinity was known. Microsatellite genotyping identified a partial haplotype from each parent that corresponds to the region of homozygosity in the patient. Assuming S318Y is a founder mutation, the number of generations separating the two parents from their common ancestor from whom they inherited S318Y was estimated as 21.7 (95% CI 3.42­69.7). CONCLUSION: EPP was therefore inherited as an autosomal recessive trait in the family. This study confirms the association between palmar keratoderma and autosomal recessive EPP.

Variations in the length of poly-C and poly-T tracts in intron 3 of the human ferrochelatase gene.

The third intron of human ferrochelatase (FECH) gene contains according to NCBI, a poly-C (11) and a poly-T (24) tracts which are located approximately 900 bp upstream from the known splice modulating SNP IVS3-48 c/t. Ferrochelatase catalyses the last step in heme biosynthesis and a deficiency of this enzyme results in the hereditary disorder of erythropoietic protopoprhyria (EPP). During the course of mutation analysis in the FECH gene among EPP patients, we observed variations in the length of the poly-C and poly-T tracts. To study these variations, we analyzed a total of 54 individuals of Swiss and Israeli origins. Among them, 37 were control subjects (23 individuals with the genotype t/t and 14 with the genotype c/t), 10 were unrelated EPP patients (genotype c/M) and 7 were unrelated asymptomatic mutation carriers (genotype t/M). The length of poly-C tract varied from 10 to 16, that of poly-T tract from 22 to 24 in the study cohort. Statistic analysis showed that the low-expressed FECH allele (IVS3-48c) is associated with poly-C12, C13 and C15 and poly-T22. In addition, the segregation of poly-C and poly-T tracts was studied in two Israeli EPP families. Instabilities, as seen by both insertion and deletion of one nucleotide between two generations, were observed only in the poly-T tract. The function of the poly-C and poly-T tracts are yet to be explored.

Awareness is the name of the game: clinical and biochemical evaluation of a case of a girl diagnosed with acute intermittent porphyria associated with autism.

Neuroporphyrias, a heterogeneous group of metabolic diseases, are diagnosed less often than their true prevalence justifies. Lack of awareness of porphyrias and their protean clinical and biochemical manifestations, is the most significant hurdle to their recognition and diagnosis. These points are reflected in the unusual case reported here, which highlights the potential damage that inappropriate management may cause when the diagnosis is missed over a long period. We diagnosed heterozygous Acute Intermittent Porphyria (AIP) in a 15 yr old girl, who first presented with autism at the age of 4 years. This phenotypic association has not been previously reported. In addition to the unrecognized phenotype, her normal urinary aminolevulinic acid and porphobilinogen, findings which are not compatible with symptomatic porphyria according to well established criteria, could also have led to a missed diagnosis of neuroporphyria. However, the diagnosis of AIP was established on the basis of a 64% reduction in erythrocyte hydroxymethylbilane synthase (HMBS) activity and the finding of a known causative AIP mutation (p.D178N). We therefore recommend that porphyria should be considered in autistic children especially when there is an atypical course or unexpected abreaction to medications. The biochemical and genetic data should be carefully evaluated in a specialized porphyria center.

Biochemical and molecular diagnosis of erythropoietic protoporphyria in an Ashkenazi Jewish family.

Erythropoietic protoporphyria (EPP) is a rare hereditary disorder due to a partial deficiency of ferrochelatase (FECH). The genotype of EPP patients features a mutation on one allele of the FECH gene and a common hypomorphic FECH IVS3-48c on the other allele (M/c). The resulting enzyme activity in patients is ∼35% of that in normal individuals. Ferrochelatase deficiency results in the accumulation of protoporphyrin in the skin, which is responsible for the clinical symptom of cutaneous photosensitivity in patients. In this study, we report the identification of a novel FECH mutation delT23 in an 11-member EPP family of Jewish origin. Two EPP siblings shared an identical genotype of delT23/IVS3-48c (M/c). They were both photosensitive and showed highly increased erythrocyte protoporphyrin. The genotype of the patients' mother, who did not present with any EPP clinical symptoms, was delT23/IVS3-48t (M/t). The patients' father, an offspring of consanguineous parents, was homozygous IVS3-48 c/c. He exhibited a mild photosensitivity, and an increase of 4-fold in erythrocyte protoporphyrin. His FECH mRNA amount was 71% of that of genotype t/t. It is the first reported case of an individual with c/c genotype who exhibits both biochemical and clinical indications of EPP. These results suggest that IVS3-48c is a functional variant of ferrochelatase. The clinical symptoms and biochemical abnormalities in the patients' father could be the result of an interaction between genetic and environmental factors. In addition, the frequency of IVS3-48c in the Ashkenazi Jewish population was estimated at 8%, which is similar to that in the European populations.

Absorption, distribution and elimination of fumonisin B(1) metabolites in weaned piglets.

The absorption, distribution and elimination of fumonisin B(1) (and B(2)) after oral administration of Fusarium verticillioides (MRC 826) fungal culture, mixed into the experimental feed for 10 days, was studied in weaned barrows. In order to determine the absorption of FB(1) from the feed marked by chromium oxide, a special T-cannula was implanted into the distal part of pigs' ileum. During the feeding of toxin-containing diet (45 mg FB(1) kg(-1)) and until the tenth day after the end of treatment, the total quantity of urine and faeces was collected and their toxin content analysed. At the end of the trial, samples of lung, liver, kidney, brain, muscle, and fat were also collected and their fumonisin content analysed by LC-MS. The fumonisins appeared to decrease the reduced glutathione content in blood plasma and red blood cell haemolysate, possibly associated with in vivo lipid peroxidation. From a data set of 80 individual data and the concentration and rate of C(r) and fumonisins (FB(1), partially hydrolysed FB(1) and aminopentol) in the chymus, it could be established that the accumulative absorption of fumonisin B(1) was 3.9% +/- 0.7%. In the chymus, the FB(1) conversions into aminopentol and partially hydrolysed FB(1) were 1.0 and 3.9%, respectively. The degree of metabolism in faeces was variable, although the main product was the partially hydrolysed form, with very small amounts of the aminopentol moiety being recovered. In the investigated tissues the FB(1) conversion to aminopentol and partially hydrolysed FB(1) was 30 and 20%, respectively.

Individualized workup: a new approach to the biochemical diagnosis of acute attacks of neuroporphyria.

Porphyria experts concur that acute attacks of AIP, VP and HCP, are invariably associated with increases in urinary PBG. Reports differ, however, as to the amount of increase indicative of an acute attack. Some authors consider excretion of at least 25-fold the upper level of normal, as indicative, whereas others regard a 10-fold or even a 2-fold increase, as sufficient indication. An additional diagnostic difficulty arises from the fact that in many individuals known to have inherited one of the acute porphyrias, PBG is persistently raised also during remission. It may be markedly elevated even in asymptomatic carriers. In the absence of a universally accepted standard for interpreting PBG results, attribution of neurovisceral or neuropsychiatric symptoms in porphyrics to an acute attack of porphyria rather than to other causes, depends largely on clinical assessment. The aim of this work was to identify reliable criteria, which will enable establishing or excluding an acute attack, on a biochemical basis. The study summarizes and interprets data obtained during classical neurovisceral acute attacks and latent phases in 20 patients (10 with AIP, 6 with VP, and 4 with HCP). Calculated increases in urinary PBG, with the upper limit of normal excretion, (8.8 micromol/24 h), defined as 100 %, revealed an overlap between values in the acute and latent phases, (1 to 18.5-fold and 2.3 to 51-fold, respectively). This overlap indicates that the workup in each case needs to be individualized. We achieved this goal, by using another method of calculation, in which the PBG value measured during an acute attack in a particular patient was divided by the PBG value measured in that patient's latent phase. Increases of 2.3 to 50.5-fold were obtained, leading to the conclusion that any increase, calculated as above, of 2.3-fold and higher, may be taken as indicative of an acute attack. An additional finding, demonstrated in the study, which might be useful for supporting the diagnosis of an acute attack, is the distinct emission peak observed at 404/621 nm, in the plasma fluorometric scan of AIP and HCP patients, during an acute attack. We conclude that comparison of the urinary PBG level and plasma fluorometric scan in the acute phase to those of the latent phase in the individual patient is the key to correct, accurate and reliable biochemical diagnosis of an acute attack in a patient previously diagnosed as a porphyric. The additional tests required for confirming a patient's first acute attack, having no data to compare with, are discussed.

Cutaneous photosensitivity induced by paclitaxel and trastuzumab therapy associated with aberrations in the biosynthesis of porphyrins.

BACKGROUND: Paclitaxel and trastuzumab are new treatments for patients with metastatic breast cancer. CASE REPORT: We describe here a 40-year-old female patient with metastatic breast cancer who developed a photosensitive rash 1 month after initiation of paclitaxel and trastuzumab therapy. The eruption appeared on the dorsal aspect of her hands, forearms, legs and face and consisted of erythema, edema and vesicles, and was associated with distal onycholysis. Aberrations in various parameters of the metabolism of porphyrins were observed in urine and erythrocytes. Sun avoidance and withdrawal of paclitaxel was followed by resolution of the rash and a return to the normal pattern of porphyrins biosynthesis. CONCLUSION: The combination of paclitaxel and trastuzumab treatment and sun exposure may induce a photosensitive reaction, associated with changes in various parameters of porphyrins biosynthesis.

Threshold Amsler grid as a screening tool for asymptomatic patients on hydroxychloroquine therapy.

BACKGROUND/AIMS: Patients taking hydroxychloroquine (HCQ) are at risk of developing classic bull's eye maculopathy. Currently, the standard Amsler grid (AG) is one of the most useful methods to identify such lesions. However, AG is a suprathreshold target and may not detect relative central scotomas. The aim of this study was to determine if the threshold Amsler grid (TAG) test, which varies light transmission through two cross polarising filters, allows increased detection of scotomas caused by HCQ toxicity. METHODS: 56 rheumatological patients taking HCQ and 12 similar patients not taking HCQ were tested by AG, red Amsler grid (RAG), and TAG. RESULTS: No scotomas were observed in patients never treated with HCQ. Among patients who had been treated with HCQ, AG revealed scotomas in two of 56 (3.64%) patients; in contrast, six (10.7%) and 37 (66.1%) scotomas were identified by RAG and TAG testing respectively. Additionally, the average area of each scotoma detected by all three methods expanded from 34.5 square degrees of central field loss on AG testing to 71 square degrees on RAG and 117 on TAG. CONCLUSION: By decreasing the perceived luminance of the suprathreshold AG, TAG testing provides a novel alternative to detect shallow scotomas and areas of depressed retinal activity secondary to HCQ toxicity.

Yeast, creatinine and false diagnosis of porphyria.

A distressingly common occurrence is the erroneous diagnosis of hepatic porphyria in patients with chronic abdominal pain in which either urinary porphyrins are elevated and/or Watson-Schwarz test is positive. This work investigates a characteristic case and points at possible pitfalls in establishing a diagnosis. In the patient described, spot urine analysis showed positive Watson-Schwarz test and increased porphyrins at three separate occasions, while normal values of precursors and porphyrins were recorded in 24-hrs. urinary collections during four hospitalization periods for acute abdominal pain. Various colorimetric and HPLC methods employed excluded the diagnosis of porphyria and led to resolving the discrepancy between home and hospital results. It was found that the false increase in porphyrins in the spot samples emerged from a substance present in yeast tablets which the patient was consuming. The positive Watson-Schwarz test obtained was probably the result of the fact that the urine samples were concentrated with creatinine values exceeding 400 mg%. The case reported above, as well as studies carried out in three healthy volunteers and in an AIP patient, led to the conclusion that in order to obtain reliable result, 24-hrs. urinary collections should be examined, rather than spot urine samples.

Bullous dermatosis of end-stage renal disease: a possible association between abnormal porphyrin metabolism and aluminium.

BACKGROUND: Bullous dermatosis (BD) is becoming increasingly recognized in patients with end-stage renal disease (ESRD). It is clinically reminiscent of porphyria cutanea tarda, but its detailed pathogenesis remains unclear. Studies have shown increased porphyrin levels in dialysis patients, and this may partly explain the skin lesions and photosensitivity evident in these patients. In experimental studies, aluminum can induce various abnormalities in porphyrin and haem metabolism. This study investigated a possible involvement of porphyrin metabolism and aluminum in the development of bullous dermatosis in chronically dialysed patients. METHODS: Three groups were studied (12 healthy controls; 12 patients on chronic dialysis without BD and six patients on chronic dialysis with BD). Clinical characteristics of these patients were evaluated and the levels of plasma porphyrins, erythrocyte porphyrins and enzymes involved in the porphyrin chain were determined. RESULTS: The patients with BD were predominantly male, 50% had ADPKD, all had been on dialysis for a long period of time (7.8 +/- 2.1 years) and all were anuric. CAPD and haemodialysis were used equally in the affected patients. Aminolaevulinic dehydratase activity was significantly reduced in all ESRD patients (892 +/- 47 versus 302 +/- 36 versus 408 +/- 37 nmol/ml RBC/h). Plasma uroporphyrins as well as RBC protoporphyrin were significantly elevated in ESRD patients (1.7 +/- 0.6 versus 21.6 +/- 4.7 versus 43.4 +/- 12.0 nmol/L) and (1.43 +/- 0.14 versus 2.4 +/- 0.42 versus 4.19 +/- 2.44 mumol/l) respectively. Serum A1 levels were markedly elevated in patients with BD (28.3 +/- 10.0 micrograms/l). Both uroporphyrin and protoporphyrin were significantly more elevated in ESRD patients with BD compared to ESRD patients without BD. CONCLUSIONS: Elevated plasma porphyrin levels in ESRD patients are caused by lack of urinary excretion and the inability of haemodialysis and CAPD therapy to remove them. These elevated porphyrin levels may lead to the development of porphyria cutanea tarda symptoms. Elevations in plasma uroporphyrin, red blood cell protoporphyrin, and elevated A1 levels suggest a possible relationship between an A1 'load' and abnormal porphyrin metabolism in the development of overt skin disease in the dialysed patient.

Alcohol-induced changes in urinary aminolevulinic acid and porphyrins: unrelated to liver disease.

Urinary porphyrins and their metabolites aminolevulinic acid (ALA) and porphobilinogen (PBG) were determined in 15 normal volunteers and in 45 alcoholics, subdivided into three groups according to their liver function tests and histology: alcoholics exhibiting no evidence of hepatocellular damage; alcoholics with fatty liver and impaired function of liver enzymes; and alcoholics with proven liver cirrhosis. The dominant trend observed in those alcoholics devoid of any evidence of liver disease was increased ALA, PBG, and uroporphyrin. Coproporphyrinuria was shared by the patients exhibiting liver damage. The data shown enabled us to differentiate between the direct, primary effect of alcohol on the heme biosynthetic pathway and the secondary indirect effect, which is probably related to liver damage that follows alcohol consumption. Evaluation of the results led to the suggestion that urinary ALA could possibly serve as a marker of alcoholism. The specificity and sensitivity of the test were found to be 87% and 80%, respectively.

Relation between uroporphyrin excretion, acute attacks of hereditary coproporphyria and successful treatment with haem arginate.

1. The increased urinary excretion of porphyrins as well as of their precursors was studied in a patient with hereditary coproporphyria during two acute attacks in which symptoms differed markedly in character and severity. 2. The increase in urinary coproporphyrin was similar in the 'mild' and in the 'severe' attack, indicating a lack of correlation between coproporphyrin level and clinical symptoms. 3. Aminolaevulinic acid, porphobilinogen and uroporphyrin exhibited significantly higher values during the 'severe' attack than during the 'mild' attack. During the severe attack these three compounds were increased 18-, 14- and 46-fold, respectively, compared with increases of 3-, 3- and 8-fold, respectively, during the mild attack. 4. The striking rise in the formation of uroporphyrin was reflected in the plasma porphyrin profile, which revealed predominance of uroporphyrin. In accordance with this finding, an increase in erythrocyte porphobilinogen deaminase of 130% was recorded. 5. The fluorescence emission spectra of saline-diluted plasma (excitation of 405 nm) showed a distinct peak at 618 nm during the 'severe' episode and a small peak during the 'mild' attack, pointing to the possibility of diagnosing an attack simply by following the fluorometric screen of plasma. 6. The 'severe' attack of coproporphyria was treated with daily infusions of haem arginate, 3 mg/kg, every day for 4 days, at the end of which period a dramatic clinical response was observed. The relief of symptoms was found to be clearly related to the moderate decrease in uroporphyrin excretion observed rather than to the steep decline in the precursors.

Decreased uroporphyrinogen decarboxylase activity in patients with end-stage renal disease undergoing hemodialysis.

Raised plasma uroporphyrin levels were found in all the 14 patients with end-stage renal disease studied, 7 of whom were on continuous ambulatory peritoneal dialysis (CAPD) and 7 on hemodialysis (HD). The elevation observed in the HD group was higher than that noted in the CAPD group; 18-fold in the former and 13-fold in the latter. The difference in uroporphyrin plasma levels between the two dialysis populations might be explained, at least partially, by the reduced activity of uroporphyrinogen decarboxylase (UROD), the enzyme which converts uroporphyrinogen to coproporphyrinogen. A decrease of 48% was noted in the HD group, whereas no change was observed in the CAPD group. A significant negative correlation (r = -0.37, p < 0.01) was found between the concentration of uroporphyrin in plasma and the activity of UROD. In view of the data shown, it is suggested that erythrocyte UROD activity should be interpreted with caution in HD patients suspected of having porphyria cutanea tarda.

Transformation, growth rate, and the heme biosynthetic pathway in V-abl-transfected fibroblasts.

The relationship between growth rate and various parameters of the heme biosynthetic pathway was studied in two cell lines of rat fibroblasts (REabl-1 and REabl-3) transfected with v-abl oncogene, coded by the Abelson murine leukemia virus, and subjected to glucocorticoid dependent transformation. In the REabl-1 cell line, whose growth rate was only slightly affected by dexamethasone (DX), almost no change was noticed either in heme content or in the enzymatic activities of aminolevulinate synthase (ALAS), porphobilinogen deaminase (PBGD), and ferrochelatase (FC) in the presence of various concentrations of DX. In the REabl-3 cell line, exhibiting a growth rate highly sensitive to DX, a significant reduction in intracellular heme concomitantly with decreases in ALAS and FC activities and a threefold increase in PBGD were noted. The fact that incubation with 10(-5)M hemin did not result in a decrease in ALAS activity raised the possibility that REabl cells lack a negative feedback control mechanism. The relationships between transformation, growth rate, and heme biosynthetic pathway are discussed.

Evidence for the interference of aluminum with bacterial porphyrin biosynthesis.

Aluminum (0.74 mM) was found to retard bacterial growth, and enhance porphyrin formation and excretion in Arthrobacter aurescens RS-2. Coproporphyrin III was shown to be the main porphyrin excreted by aluminum-exposed A. aurescens RS-2 cultures and by RS-2 cultures grown under anoxic conditions. Synthesis and excretion of porphyrins in A. aurescens RS-2 increased in a dose-dependent manner when the bacteria were exposed to increasing aluminum concentrations. Incubation of A. aurescens RS-2 with delta-aminolevulinic acid (delta-ALA, 1.2 mM) brought about the intense formation and excretion of porphyrins by the cells, in the presence or absence of aluminum. delta-ALA slightly enhanced the toxicity of aluminum towards RS-2 bacteria. Furthermore, the intracellular concentration of heme was reduced by 63.9 +/- 8.67% in aluminum-exposed RS-2 bacteria when compared with control cultures. The results are discussed in light of the recent finding concerning aluminum toxicity and porphyrin biosynthesis in microorganisms.

Interference of ofloxacin with determination of urinary porphyrins.

The second-generation quinolone ofloxacin interferes with the screening test of porphyrins. We observed a 20-fold increase in the porphyrin concentration measured in urine of an ofloxacin-treated patient, compared with drug-free normal urine. Two other fluorinated 4-quinolones tested, norfloxacin and ciprofloxacin, had a less marked effect (a twofold increase), whereas the first-generation quinolone, nalidixic acid, did not affect the measured porphyrin concentration at all. The interference is probably due to the overlap in the emission fluorescence spectra of ofloxacin and urinary porphyrins at approximately 600 nm. To avoid a false-positive diagnosis of porphyria, we suggest using HPLC to separate ofloxacin (10-min retention time) from urinary porphyrins (which only start to elute at 12 min). Nonetheless, given a threefold increase in urinary porphyrins observed in the urine of an ofloxacin-treated patient, we also discuss a possible interference of the drug with the metabolism of porphyrins.

Protoporphyrin biosynthesis in melanoma B16 cells stimulated by 5-aminolevulinic acid and chemical inducers: characterization of photodynamic inactivation.

The stimulation of protoporphyrin (PP) biosynthesis in B16 melanoma cells in order to facilitate photodynamic cell killing was studied. Biosynthesis and accumulation of PP in the melanoma cells was increased from 8 to 15 pmol/mg protein by the use of dimethyl-sulfoxide (DMSO), a differentiation-inducer. Treatment of the cells with the porphyrogenic agent allylisopropyl-acetamide (AIA) stimulated an additional PP increase. The most remarkable enhancement of intracellular PP was achieved by the supplementation of 5-aminolevulinic acid (5-ALA) to the growth medium following the addition of DMSO and AIA during the induction phase. The intracellular concentration of PP exceeded 21,950 pmol/mg protein following combined stimulation by DMSO/AIA and 5-ALA. The porphyrins produced in the incubated cells, in serum-depleted medium, consisted of 95% PP; 88% of it was recovered from the cells and only 7% was excreted into the medium. Photosensitization of the B16 melanoma cells containing high PP concentrations was effective even at low light doses. Potassium (K) efflux was the first measurable sign of cell damage determined by X-ray microanalysis (XRMA) following fast liquid-nitrogen fixation. During a 1 min interval, 70% of cellular K was lost. After 5 min illumination, complete cell destruction was detected by scanning electron microscopy (SEM) and XRMA. The photodamaged cells showed influx of Na, Cl and Ca ions accompanying the immediate K losses. Ultrastructural cell damage was manifested by disintegration of the outer membrane. Total cell death of B16 melanoma cells was achieved by chemical induction of endogenous PP and photosensitization.