Prevention of photosensitivity with action spectrum adjusted protection for erythropoietic protoporphyria

Erythropoietic protoporphyria is a genetic disease characterized by sensitivity to sunlight caused by the accumulation of protoporphyrin IX. Photoprotection against ultraviolet A and visible light is necessary for erythropoietic porphyria patients because the absorption spectrum of protoporphyrin IX lies in both ultraviolet A and visible light region. We developed a novel index, in vitro porphyrin protection factor, based on the protoporphyrin IX absorbance spectrum. We also selected appropriate photoprotective products designed according to protoporphyrin IX absorbance. The porphyrin protection factors of a combination of make-up base with a powder as well as with a liquid foundation were significantly higher than those of a conventional sunscreen product, even at a small application dose. An in-use test carried out for 6 months showed that the efficacy of these products was 78.3%, and no adverse reactions were observed. Male subjects preferred liquid foundation, whereas all female subjects used powder foundation. The preference of the subjects could lead to the long-term use of the tested products. In conclusion, this study provided a new approach to improve photoprotection in erythropoietic protoporphyria patients.

A Novel Mutation in the FECH Gene in a Czech Family with Erythropoietic Protoporphyria and a Population Study of IVS3-48C Variant Contributing to the Disease

Erythropoietic protoporphyria (EPP), a chronic erythropoietic porphyria, is characterized by excess accumulation of protoporphyrin, particularly in erythroid cells. EPP inheritance is complex, almost always associated with two molecular defects. In most EPP patients, clinical expression requires coinheritance of a private ferrochelatase (FECH) mutation trans- to a hypomorphic FECH*IVS3-48C allele. This leads to a decrease of FECH activity below the critical threshold. This is characterized by cutaneous photosensitivity in early childhood such as itching, burning, swelling and redness in sun-exposed areas. Hepatic failure occurs in some patients (about 1-10 % of EPP patients), which may necessitate liver transplantation. We investigated a Czech family with two patients with manifested EPP in four generations. We found a novel mutation, c.84G >A, in the FECH gene in four individuals including proband and his mother (G84A transition in exon 2; p.W28*). Both clinically manifested probands inherited the hypomorphic IVS3-48C allele as well, while two clinically latent individuals with FECH mutation did not. To address the question whether the relatively low incidence of EPP in the Czech Republic might be due to lower frequency of the IVS3-48C allele, we screened for the frequency of the low expression allele in a control Czech (West Slaves) Caucasian population. Such study has not been performed in any Slavic population. Among 312 control individuals, there were no IVS3-48C/C (c.68-23C-T) homozygotes; 35 IVS3-48C/T heterozygous individuals were detected. The frequency of IVS3-48C allele was thus found to be 5.5 % in the Czech population, comparable to most West Caucasian populations.

Bone mineral density and vitamin D levels in erythropoietic protoporphyria

Erythropoietic protoporphyria (EPP) is a rare disease with painful cutaneous photosensitivity, in which patients are recommended to avoid sun exposure, and wear sunscreen and adequate clothing. Our aim was to study bone mineral density (BMD) and other mineral parameters, including serum 25(OH)D levels, to evaluate the impact of these measures in the follow-up of EPP patients. A cross-sectional study of ten EPP patients (median age 25; range 22-55, four males and six females), was performed evaluating clinical features, biochemical values (bone markers and serum 25 hydroxyvitamin D), and BMD. Median serum 25(OH)D level was 19.65 ng/ml [17.50; 24.80]. Four patients had 25(OH)D in insufficiency range (20-30 ng/ml) and five patients in the deficiency range (<20 ng/ml). Lumbar T-score median levels were in the osteopenia range in both females (-1.50 [-2.30; -1.0]) and males (-1.90 [-2.40; -0.70]). Also, in the female group median femoral neck T-score were in the osteopenia range (-1.20 [-1.60; -0.60]). This is the first study reporting low BMD in EPP patients. Osteoporosis, osteopenia, and vitamin D deficiency are frequent findings in EPP patients. The contribution of sunlight avoidance measures to these results remains to be clarified. Serum levels of protoporphyrins were not related to these alterations and other factors should be investigated. We suggest that the monitoring of serum vitamin D levels in EPP patients should be mandatory, as well as vitamin D and calcium supplementation.

Electrospray ionization on porous spraying tips for direct sample analysis by mass spectrometry: enhanced detection sensitivity and selectivity using hydrophobic/hydrophilic materials as spraying tips

RATIONALE

Despite various porous materials having been widely adopted as spraying tips for direct sample analysis using electrospray ionization mass spectrometry (ESI-MS), the effect of surface property and porosity of spraying tip materials on their analytical performances is not clear. Investigation of their relationships could provide insight into the proper choice and/or design of spraying tip materials for direct sample analysis.

METHODS

The effect of spraying tip materials with different polarities, including polyester and polyethylene (hydrophobic) and wood (hydrophilic), on the detection sensitivity for a variety of compounds, and on the ESI onset voltage, were studied using ESI-MS. The porosity of each type of spraying tip was characterized by scanning electron microscopy (SEM). Factors governing the detection sensitivity were determined based on the correlation of the detection sensitivity to the ESI onset voltage, the polarity, and the porosity of the spraying tip materials.

RESULTS

Hydrophobic tips (i.e., polyester and polyethylene) show better detection sensitivity for polar compounds but not for non-polar compounds, while hydrophilic tips (wooden tips) show the opposite effect. This phenomenon could be due to the difference in interaction between the analytes and the tips, causing the analytes to adsorb on the tip to different extents. In addition, the micro-porous nature of the tips could facilitate solvent diffusion for transporting analytes to the tip and maintain a stable spray for recording MS data. With the proper choice of spraying tip materials, trace amount of analytes at the picomole level can be detected with minimal sample pretreatment.

CONCLUSIONS

Both the polarity and the porosity of the spraying tip materials could significantly affect detection sensitivity for a wide variety of analytes. With proper choice of spraying tip material, ESI on a porous spraying tip could be a sensitive method for the direct analysis of daily life samples.

Genetic study in a Singaporean patient with erythropoietic protoporphyria

Erythropoietic protoporphyria (EPP) is a rare autosomal dominant disorder of haem biosynthesis resulting from a partial decrease in ferrochelatase (FECH) activity which leads to the excessive accumulation of protoporphyrin in blood, erythrocytes and tissues. Cutaneous manifestations of photosensitivity usually appear in early infancy upon the first sun exposures. This normally requires the co-inheritance of a common hypomorphic FECH allele and a deleterious FECH mutation. Here, we report the first Singaporean Chinese patient with EPP characterized at the molecular level.

Excessive erythrocyte PPIX influences the hematologic status and iron metabolism in patients with dominant erythropoietic protoporphyria

Partial deficiency of the last enzyme of the heme biosynthetic pathway (namely ferrochelatase, FECH) in humans is responsible for erythropoietic protoporphyria (EPP). This disorder is characterised by painful photosensitivity, due to excessive production of protoporphyrin IX (PPIX) by erythrocytes. Controversial hypotheses have been proposed to explain the hematologic and iron status of EPP patients. In the present work, we explored these parameters in 55 patients with dominant EPP recruited at the French Center of Porphyrias (Colombes, France) and confirmed by molecular analysis. Our data show that erythrocyte accumulation of PPIX in EPP patients influences hematologic and iron status. Patients studied had a mild anemia and thrombocytopenia, as shown by the downward shift of hematologic parameters, which positively correlated with the amount of erythrocyte PPIX. Interestingly, erythropoiesis did not seem to be limited by iron supply in patients, since serum iron and soluble transferring (Tf) receptor (sTfR) were normal. However, iron and Tf saturation negatively correlated with erythrocyte PPIX. Moreover, and as previously described in a mouse model of EPP, we noted a positive correlation between erythrocyte PPIX and Tf levels. Altogether, these results suggest a positive effect of PPIX on the synthesis on Tf, which could facilitate the mobilization of tissue iron stores to meet erythropoiesis requirement. Based on these observations and previous results in EPP mouse model, we propose that the PPIX-liver transferrin pathway plays a role in the orchestration of iron distribution between peripheral iron stores, the spleen and the bone marrow.

Erythropoiesis and iron metabolism in dominant erythropoietic protoporphyria

Erythropoietic protoporphyria (EPP) results from deficiency of ferrochelatase (FECH). Accumulation of protoporphyrin IX causes life-long acute photosensitivity. Microcytic anemia occurs in 20% to 60% of patients. We investigated 178 patients with dominant EPP confirmed by molecular analysis. Erythropoiesis was impaired in all patients; all had a downward shift in hemoglobin (Hb), and the mean decreased in males by 12 g/L (1.2 g/dL). By World Health Organization criteria, 48% of women and 33% of men were anemic. Iron stores, assessed by serum ferritin (sFn), were decreased by two-thirds, but normal serum soluble transferrin receptor-1 and iron concentrations suggested that erythropoiesis was not limited by iron supply. FECH deficiency in EPP appears to lead to a steady state in which decreased erythropoiesis is matched by reduced iron absorption and supply. This response may in part be mediated by protoporphyrin, but we found no correlation between erythrocyte protoporphyrin and Hb, sFn, total iron-binding capacity, or transferrin saturation.

Erythropoietic protoporphyria patients in Slovenia

BACKGROUND

There are only scarce epidemiological data on the prevalence of erythropoietic protoporphyria (EPP) in a given population. The aim of this study was to assess the prevalence of EPP within the Slovenian population.

MATERIALS AND METHODS

The patients were selected by routine examination of photosensitive patients and by studying hospital records. A quantitative spectrophotometric method was used to assess protoporphyrin, with values larger than 530 nm/l considered elevated.

RESULTS

32 EPP patients were detected, which allows us to estimate the prevalence of EPP in Slovenia at 1.75 per 100,000 inhabitants.

Stimulation of fecal fat excretion and the disposal of protoporphyrin in a murine model for erythropoietic protoporphyria

Erythropoietic protoporphyria (EPP) is characterized by toxic accumulation of the hydrophobic compound protoporphyrin (PP). Ferrochelatase-deficient (fch/fch) mice are an animal model for human EPP. Recently, we have demonstrated that the accumulation of another hydrophobic compound, unconjugated bilirubin, could effectively be treated by stimulation of fecal fat excretion. We investigated whether stimulation of fecal fat excretion enhanced the disposal of PP in fch/fch mice. Fch/fch mice were fed for 8 wk with a high-fat diet (16 wt% fat; control) or with the high-fat diet mixed with either a nonabsorbable fat (sucrose polyester) or the intestinal lipase inhibitor orlistat. The effects of the treatments on fecal excretion of fat and PP and on hepatic PP concentrations were compared with control diets. Fecal fat excretion in fch/fch mice on a high-fat diet was higher than in mice on a low-fat diet (+149%, P < 0.05). Sucrose polyesters and orlistat increased fecal fat excretion even more, up to sixfold of control values. However, none of the different treatments affected fecal PP excretion or hepatic PP concentration. Treatment of fch/fch mice with a high-fat diet, a nonabsorbable fat diet, or with orlistat increased the fecal excretion of fat but did not increase fecal PP excretion or decrease hepatic PP concentration. The present data indicate that accumulation of PP is not amenable to stimulation of fecal fat excretion.

Regulation of protein synthesis by the heme-regulated eIF2alpha kinase: relevance to anemias

During erythroid differentiation and maturation, it is critical that the 3 components of hemoglobin, alpha-globin, beta-globin, and heme, are made in proper stoichiometry to form stable hemoglobin. Heme-regulated translation mediated by the heme-regulated inhibitor kinase (HRI) provides one major mechanism that ensures balanced synthesis of globins and heme. HRI phosphorylates the alpha-subunit of eukaryotic translational initiation factor 2 (eLF2alpha) in heme deficiency, thereby inhibiting protein synthesis globally. In this manner, HRI serves as a feedback inhibitor of globin synthesis by sensing the intracellular concentration of heme through its heme-binding domains. HRI is essential not only for the translational regulation of globins, but also for the survival of erythroid precursors in iron deficiency. Recently, the protective function of HRI has also been demonstrated in murine models of erythropoietic protoporphyria and beta-thalassemia. In these 3 anemias, HRI is essential in determining red blood cell size, number, and hemoglobin content per cell. Translational regulation by HRI is critical to reduce excess synthesis of globin proteins or heme under nonoptimal disease states, and thus reduces the severity of these diseases. The protective role of HRI may be more common among red cell disorders.

Erythropoietic protoporphyria and pretransplantation treatment with nonbiological liver assist devices

Erythropoietic protoporphyria (EPP) is a disease of the heme metabolism due to a deficiency of ferrochelatase, leading to accumulation of protoporphyrin (PPIX) in the erythrocyte (red blood cell [RBC]). The major clinical manifestation in EPP is photosensitivity; however, in a small number of patients liver failure is a significant complication and liver transplantation is the only treatment option. Damage to both abdominal skin and organs occurs when exposed to operating light; however, this problem can be ameliorated by the use of filters that block the transmission of light with wavelength below 470 nm. A more unusual but very serious complication postoperatively is severe motor neuropathy, with few or no known acute available precautions. An effective treatment option is needed to manage EPP crises and to prevent complications after liver transplantation. We successfully treated a patient with EPP-induced liver failure with the molecular adsorbents recirculating system (MARS) and Prometheus in independent sessions. Following treatment with MARS we found a 9.1% reduction of the RBC-PPIX concentration and a 5.9% reduction after treatment with the Prometheus system. Plasmapheresis made a reduction in RBC-PPIX concentration of 0.8%. Following treatment sessions with MARS and Prometheus, the clinical condition was markedly improved and orthotopic liver transplantation was performed without further complications. In conclusion, extracorporeal therapy with MARS or Prometheus seems to be efficient in reducing RBC-PPIX concentration in comparison to plasma exchange.

Erythropoietic protoporphyria in the U.K.: clinical features and effect on quality of life

BACKGROUND

Erythropoietic protoporphyria (EPP) is a rare inherited photodermatosis that causes lifelong painful photosensitivity. Neither its full clinical spectrum nor its impact on quality of life (QoL) has been investigated in a large cohort of patients.

OBJECTIVES

To document the clinical features of EPP and its impact on QoL in a high proportion of all patients with EPP resident in the U.K.

METHODS

Patients with EPP were identified from U.K. clinical databases and assessed by the same clinical investigator over a 7-month period using a standardized proforma and validated adult (Dermatology Life Quality Index, DLQI) and children's (Children's Dermatology Life Quality Index, CDLQI) QoL questionnaires.

RESULTS

Three hundred and eighty-nine living patients with EPP were identified, of whom 223 [114 females, 109 males; median age 34 years (range: 5-87), from 193 families] were investigated. Total erythrocyte porphyrin (TEP) was higher in males (median: 25.3 micromol L1) than females (median: 19.3 micromol L1). The median ages at onset and diagnosis were 1 and 12 years, respectively. Median times for onset of symptoms after sun exposure, onset of signs (oedema, erythema) and resolution of symptoms were 20 min, 6 h and 3 days, respectively. Most patients reported absence of protection by glass (92%), priming (85%), exacerbation by wind (68%), no family history of photosensitivity (56%), no symptoms during winter (56%) and had chronic skin lesions (79%). Symptoms changed little with age but improved during pregnancy in 47% of gravid women. Most patients used protective clothing and a sunscreen; 28% were taking beta-carotene and a further 56% had taken it; 29% were not under regular medical care. Two patients (1%) had liver failure and 8% reported gallstone disease. QoL was markedly impaired, with scores similar to those in severe dermatological disease (mean DLQI score 14.0, n = 176; mean CDLQI score 12.8, n = 44), indicating a large effect on patients' lives. DLQI scores correlated weakly with TEP (rs = 0.228; P = 0.002) and time to onset of symptoms (rs = -0.233; P = 0.002) but not with age at onset.

CONCLUSIONS

EPP is a persistent, severely painful, socially disabling disease with a marked impact on QoL. Its diagnosis is often overlooked. None of TEP, age at onset nor time to onset of symptoms is a useful predictor of impaired QoL in individual patients.

[Iron biochemical screening and development in infants from 6 to 24 month, by socioeconomic background, Cordoba Argentina]

AIMS

To correlate the iron biochemical screening with cognitive and motor development, related to social background, in 6 to 24 month infants.

METHODS

a population - based study of 276 children. The iron deficiency was determine by the modified criterion of Hillman (1996), combining three different screenings tests: serum ferritin, hemoglobin and erythrocyte protoporphyrin. To analyse development we used Bayley II Scale.

RESULTS AND CONCLUSIONS

the anaemia was significative different (p< 0,05) between social levels, 36% in children with low socioeconomic background, 8% for the high one and iron deficiency without anaemia 42% in the total population. The motor development was homogeneous by social groups, showed 1% significative delay, 8% light delay. But the mental development shows significative differences (p<0,05) in both light and significative delay, been the must affected children with low socioeconomic background.

Red blood cell exchange transfusion in two patients with advanced erythropoietic protoporphyria

BACKGROUND

Erythropoietic protoporphyria (EPP) is a rare, autosomal dominant genetic disorder caused by the decreased or absent activity of ferrochelatase, the final enzyme in the heme biosynthetic pathway. This enzyme defect in peripheral blood progenitor cells leads to the accumulation of protoporphyrin deposits in multiple tissues. Plasmapheresis has been previously reported as an adjunctive therapy for patients with advanced hepatic EPP. Because the concentration of protoporphyrins is severalfold higher inside the red blood cell (RBC) compared to plasma, it was hypothesized that RBC exchange therapy might absorb excess protoporphyrins from the plasma and serve as an effective therapy to reduce protoporphyrin load in patients with advanced hepatic EPP. The effectiveness of RBC exchange plus hematin versus plasmapheresis plus hematin in two patients with advanced hepatic EPP is reported.

STUDY DESIGN AND METHODS

Two patients with advanced hepatic EPP were treated with RBC exchange and plasmapheresis in the setting of recurrent disease in the graft (Patient 1) or preparation for liver transplantation (Patient 2). In vitro studies were performed to test transport of protoporphyrins from patients' plasma to normal RBCs.

RESULTS

Compared with plasmapheresis, RBC exchange was more effective, for the duration of the therapy, in reducing blood levels of protoporphyrins. Liver function tests, however, showed only a modest improvement during therapy. In vitro extracellular protoporphyrin were rapidly adsorbed into normal RBCs.

CONCLUSION

Neither RBC exchange nor plasmapheresis prevented progressive hepatic deterioration in advanced hepatic EPP despite a significant decrease in protoporphyrin levels.