Free Erythrocyte Protoporphyrin Research Articles

Iron Nutritional Status Is Improved in Brazilian Preterm Infants Fed Food Cooked in Iron Pots

To determine the efficacy of cooking food in iron pots to prevent anemia in premature infants, a longitudinal study on iron nutritional status was conducted in preterm, healthy infants from families of low socioeconomic level between mo 4 and 12 of life. The infants were divided randomly into two groups. The study group consisted of 22 infants whose food was cooked in iron pots; the control group consisted of 23 infants whose food was cooked in aluminum pots. Supplemental iron [2 mg/(kg⋅d)] was recommended from 15 d to 12 mo of age for both groups. At 12 mo of age, the group fed food cooked in iron pots had significantly better hematologic values than the group fed food cooked in aluminum pots. Differences included hemoglobin (116 ± 16 vs. 103 ± 20 g/L, P= 0.02), hematocrit (0.35 ± 0.04 vs. 0.31 ± 0.05, P= 0.005), mean corpuscular volume (72.1 ± 10.4 vs. 62.7 ± 11.1 fL, P= 0.005), free erythrocyte protoporphyrin (0.78 ± 0.60 vs. 1.46 ± 0.94 mol/L, P= 0.006) and serum ferritin (median 5 vs. 0 g/L, P= 0.001). No significant differences between groups were observed in serum iron concentration, total iron-binding capacity or transferrin saturation. Iron deficiency anemia (hemoglobin ≤ 110 g/L) was observed in 36.4% (8 of 22) of infants in the group fed food cooked in iron pots and in 73.9% (17 of 23) of the infants fed food cooked in aluminum pots (P= 0.03). These results indicate that the iron added to food cooked in iron pots is bioavailable. However, this increased iron availability was insufficient to satisfy the high iron requirements of this group of preterm infants.

Limitations of solvent fractionation methods for urinary and faecal porphyrins.

The porphyrias are a group of rare, mainly inherited, disorders of haem biosynthesis, characterized by the accumulation and excessive excretion of haem precursors. Diagnosis relics heavily upon laboratory investigation, in particular the measurement of the prophyrin precursors 5-aminolaevulinic acid (ALA) and porphobilinogen (PSG) in urine, free protoporphyrin in erythrocytes, fluorescence emission spectrophotometry of plasma and the identification of porphyrins excreted in excess amounts in urine and faeces. High-performance liquid chromatography (HPLC) is the preferred tool for porphyrin analysis since it is capable of resolving all porphyrins of clinical importance, including isomers and metal chelates. Methods involving partition between organic solvents and aqueous phases of varying acidity to separate urinary porphyrin into a uroporphyrin fraction and a coproporphyrin fraction, and faecal porphyrin into a coproporphyrin fraction and protoporphyrin fraction, appear attractive to many laboratories because no special equipment is required. One such method is recommended in the current Association of Clinical Pathologists Broadsheet! on the investigation of disturbances of porphyrin metabolism.

Iron deficiency in 1- to 3-year-old children. A pediatric failure?

To determine the prevalence of iron deficiency and iron deficiency anemia in children aged 1 to 3 years in an urban population. Venous blood was measured for levels of hemoglobin, ferritin, free erythrocyte protoporphyrin, and lead in children seen for well-child visits. Children with histories of chronic illness, prematurity, blood dyscrasias, and acute illness were excluded. The private practice offices of 4 pediatricians in the New York City area. A consecutive sample of 504 children aged 1 to 3 years was included. More than one third (35%) of the children demonstrated evidence of iron insufficiency; 7% were iron deficient without anemia, and 10% had iron deficiency anemia. Because the association of iron deficiency anemia with mental and psychomotor impairment during the first 2 years of life no longer seems to be in doubt, the high prevalence of iron deficiency anemia found in the 1- to 2-year-old children in this study is disturbing. This suggests the need for greater efforts at the prevention of iron deficiency during the second year of life.

Percentile estimates for transferrin receptor in normal infants 9-15 mo of age

To establish percentile estimates of transferrin receptor (TfR) for healthy infants, plasma TfR was measured in 485 healthy infants 9-15 mo of age from Edmonton, Toronto, Montreal, and Halifax. Education and income of the sample families were reflective of the average family based on the 1991 census estimates. The mean (+/-SD) plasma TfR concentration was 4.4 +/- 1.1 mg/L. As expected in the infant population, there were no differences in TfR concentrations as a result of sex, and within this small age range there was no significant change across age. Furthermore, the TfR concentration in plasma was not associated with hemoglobin, serum ferritin, or free erythrocyte protoporphyrin. TfR has been shown to be a sensitive, quantitative measure of tissue iron deficiency not affected by inflammation and is potentially important in the diagnosis of iron deficiency, but there is a lack of normative data, particularly in infants, who are at highest risk of iron deficiency. If TfR proves useful in the diagnosis of iron deficiency, the current data will be useful as a reference standard for healthy infants.

The laboratory assessment of iron status — an update

The description by Ramsay in 1957 of a practical way of determining the total iron binding capacity of serum (a measure of transferrin concentration) provided a diagnostic test for both iron deficiency and iron overload. Since 1957 the introduction of the assay for serum ferritin (in 1972) has made it possible to assess the levels of storage iron in normal subjects and assays for free erythrocyte protoporphyrin and the circulating transferrin receptor methods to evaluate iron supply for erythropoiesis. In 1957 iron metabolism in man was already well understood but its evaluation relied on measurement of tissue iron concentrations and the use of radioisotopes of iron to measure rates of erythropoiesis. The evaluation can now be carried out using the various blood assays along with the measurement of haemoglobin concentration but interpretation of the measurements in disease still requires an understanding of the way in which these measures are influenced by pathological processes.

Lead levels in Maryland construction workers.

A cross-sectional study of unionized construction workers not currently known to be performing lead work was conducted. Participants completed an interviewer-administered questionnaire obtaining information about demographics, work history, other possible sources of lead exposure and health status (including hypertension, noise-induced hearing loss and renal disease). Blood was then obtained via venipuncture for whole blood lead level, hematocrit and free erythrocyte protoporphyrin determination. Two hundred and sixty-four Maryland construction workers had median whole blood lead determinations of 7 micrograms/dl and mean values of 8.0 micrograms/dl, with a skewed distribution ranging from 2 to 30 micrograms/dl. None were currently engaged in known lead work. Blood lead levels were significantly higher for the 124 who had 'ever' worked in demolition (8.8 micrograms/dl vs. 7.2 micrograms/dl, p = .004), and for the 79 who had ever burned paint and metal and welded on outdoor structures compared to the 48 who had done none of these activities (8.6 micrograms/dl vs. 6.8 micrograms/dl, p = .01). The 58 workers who had ever had workplace lead monitoring performed had higher lead levels (9.7 vs. 7.5 micrograms/dl, p = .003). Blood lead levels increased with age, and cigarette smoking. African Americans (N = 68) had higher lead levels (9.1 vs. 7.5 micrograms/dl, p = .01). There were only two women in the study, one with a lead level of 21 micrograms/dl and one, 7 micrograms/dl. Blood lead levels did not predict either systolic or diastolic blood pressure in this population. However, there was a significant interaction between race and lead as predictors of blood pressure, with blacks demonstrating a trend-significant correlation, and whites showing a nonsignificant but negative association. Demolition and hotwork on outdoor structures are known to cause acute episodes of lead poisoning. They also appear to cause slight but persistent increases in blood lead levels. Future workplace regulation should recognize and seek to maintain the low baseline now apparent even in urban, East Coast, construction workers.

Iron status and diet at two years of age: a longitudinal study of healthy Norwegian and immigrant children

This paper reports the results from a longitudinal study on iron status and diet among Norwegian and immigrant children living in the same residential area. This was the second part of the study and the children were two years old. All mothers with a normal pregnancy and delivery were invited to participate, and 80 of 95 eligible, accepted. Iron status analyses were carried out for 78 healthy children; 37 Norwegians and 4 1 immigrants (20 of Turkish origin). More immigrant children had depleted iron stores, compared to Norwegians. The median values for haemoglobin (Hb), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), serum ferritin (SF), transferrin saturation (TfS), free erythrocyte protoporphyrin (FEP) and transferrin receptor (TfR) were all within normal ranges. The differences between immigrants and Norwegians were significant except for Hb and SF. There was a rise in MCV and TfS and a decline in TfR among both Norwegian and immigrant children from one to two years, and a decline in SF among the Norwegians. The Norwegian children had a higher intake of soft drinks, dark bread and different iron-rich bread spreads than the immigrants, who had a higher intake of orange juice, and a more frequent use of citrus fruits than the Norwegians. Milk intake was negatively related – and consumption frequency of brown whey cheese was positively related – to iron stores indicated by SF values above or below 15 pg/L. The results suggest that differences in food intake may explain the lower iron status in immigrants compared to Norwegians. More attention should be directed to children's diet and iron status in the second and probably third years of life

Prevalence of iron deficiency anemia in female adolescents in Taboaoa da Serro, SP. Brazil

It was studied an equiprobabilistic sample of 262 female teenagers living in the city of Taboão da Serra, Brazil, with the aim of evaluating the prevalence of anemia and iron-deficiency. Anemia was identified by the hemoglobin level and the prevalence of iron-deficiency was determined through the concentration of free erythrocyte protoporphyrin. It was observed a prevalence of 17.6% of anemia, and its occurrence was inversely related to factors indicative of the economic-social level: income, schooling of parents and home's characteristics. The presence of anemia was higher in the group that did not have reached menarche, and its occurrence did not show relation with the interval between menstrual cycle. The prevalence of iron-deficiency was of 29,4% and it was not verified correlation between the bloody hemoglobin and the free erythrocyte protoporphyrin, except in severe cases of anemia.

Transient erythroporphyria of infancy

We describe a neonate with hemolytic disease of the newborn in whom a photosensitivity eruption developed during phototherapy for treatment of hyperbilirubinemia. Free erythrocyte protoporphyrin and zinc protoporphyrin levels were markedly elevated during the neonatal period. Porphyrin levels were normal at 19 weeks of age. The infant had residual skin atrophy and showed clinical and radiologic evidence of kernicterus. The pathogenesis of transient porphyrinemia associated with hemolytic disease of the newborn is unclear.

Evolution of lead toxicity in a population of children

A 3 years study was conducted to determine the evolution of blood lead concentrations (PbB) and free erythrocyte protoporphyrins (FEP) as indicators of absorption and biochemical damage in children (7-12 years old) living within one kilometer of a metallurgic factory that processes lead in Torreón, Coahuila, México. In addition, neuromuscular conduction velocity, motor coordination and IQ where determined as indicators of physiological damage. During this period of time the children showed increased lead blood concentrations of 19.2 +/- 4.5 micrograms dl-1 at the beginning of the study to 27.5 +/- 4.9 micrograms dl-1 at the end. Likewise, FEP increased from 56.6 +/- 20.0 micrograms dl-1 to 92.9 +/- 28.9 micrograms dl-1. Physiological damage was evident since motor coefficients as well as IQ tests were reduced significantly when compared to children (7-12 years old) living 4.5 km away from the factory who showed PbB = 8.9 +/- 1.3 micrograms dl-1 and FEP = 16.9 +/- 4.7 micrograms dl-1 throughout the study. Based on these data it was possible to define three different groups with regards to lead toxicity sensitivity.

The prevalence of iron depletion and iron-deficiency anaemia in a randomly selected group of infants from four Canadian cities

Our objective was to estimate the prevalence of iron depletion and iron deficiency anaemia, and factors affecting the prevalence, in healthy infants living in 4 Canadian cities. The study was cross-sectional and included 428 randomly selected evaluable subjects, ages 8 – 15 months. Multiple comparison showed no significant differences in mean hemoglobin, ferritin or free erythrocyte protoporphyrin results among the 4 cities. Only 4.3% of the sample were anaemic (Hb <110 g/L and ferritin ≤10 μg/L or free erythrocyte protoporphyrin ≥100 μg/L). We concluded that the rate of iron deficiency anaemia is low in healthy urban infants. Screening for this group is unnecessary.

ATTENTION, MEMORY AND LEARNING ARE INVERSELY RELATED TO DEGREE OF IRON DEFICIENCY IN ADOLESCENT FEMALES. † 801

Objective: To examine the association in adolescents between iron deficiency and specific neurocognitive functions, including attention, memory and learning. Methods: 28 girls, age 15 +/- 1.5 years, all> Tanner III, participated. New patients to Children's Hospital of Pittsburgh Adolescent Medicine are routinely screened with a Complete Blood Count (CBC). Indications of possible iron deficiency are mean corpuscular volume (MCV) 12.5%. Girls with suspected iron deficiency and with normal values underwent several hematological tests: hemoglobin (hb), MCV, iron, total iron binding capacity(% Saturation), and free erythrocyte protoporphyrin (FEP). All also underwent a 2-hour neurocognitive battery: measures of intelligence (Weschler Intelligence Scale for Children-III, WISC-III, Information and Picture Completion subtests), attention (Digit Vigilance Test), memory and learning(Wide Range Assessment of Memory and Learning, WRAML, and Child Selective Reminding Test) and behavior (Child Behavior Checklist, CBCL, internalizing and externalizing scores). Results: 10 girls were found to have normal iron status; 10 were iron depleted but not anemic; 8 were iron deficient and anemic. Below are the correlation coefficients of the neurocognitive and behavioral battery versus hematological parameters. Values in bold are in the expected direction and significant at p<.05. Values with * are p<.10. Table Discussion: These data suggest that reductions in circulating levels of iron during adolescence are associated with adverse effects on aspects of neurocognitive and behavioral function. These associations can be identified in some non-anemic but iron-depleted individuals.

Heavy metals as indirect causative factors of capillaropathy.

By applying systemic analysis to a set of random variables, representing blood or urine concentrations of certain enzymes, lipids and metals, three direct causative factors of capillaropathy, in its early stage, i.e. leucine amino peptidase, free erythrocyte protoporphyrin and C(3)-complement, have been found. The interactions between the early stage of capillaropathy and these factors have been quantitatively described and a formula for prognosing the capillaropathy occurrence has been proposed. It has also been shown that the following heavy metals Pb, Cd, Cr, Cu, Mg, Fe and Ca, through their direct or indirect interactions with C(3)-complement, exert an influence on the occurrence and intensity of capillaropathy. Since direct causative factors of a given pathology can serve as its markers, the completeness of the set of the capillaropathy markers, formed from the causative factors, and their contributions to this pathology have been evaluated. The results were obtained by examining a population of male residents chronically exposed to heavy metals (Pb, Cu) in the environment.

Relationship between blood lead and dietary iron intake in preschool children: A cross-sectional study

The relationship between dietary iron intake and blood lead levels in urban preschool children was investigated in a cross-sectional study of 299 children from 9 months to 5 years old. Mothers of children attending the University of Maryland Pediatric Ambulatory Clinic volunteered for the children and themselves to join the study. The data collected included nutritional status, socioeconomic status, medical history, and potential sources of lead exposure. Blood samples from all participants were evaluated for levels of blood lead, serum iron (ferritin), free erythrocyte protoporphyrin, calcium, and hematocrit. The average blood lead level (standard deviation) in the studied population was 11.4 (73) μg/dL. With multiple linear and logistic regression analyses to adjust for covariates, a negative association ( P = 0.03) between blood lead and dietary iron intake was found. This finding is consistent with similar results from experimental studies. It is concluded that there is evidence that higher dietary iron intake is associated with lower blood lead among urban preschool children in the studied population.

An Evaluation of Unleaded Petrol as a Harm Reduction Strategy for Petrol Sniffers in an Aboriginal Community

In mid 1989, leaded petrol was replaced by unleaded petrol to reduce lead toxicity in petrol sniffers in Maningrida, a remote Aboriginal community in Northern Australia. RETROSPECTIVE REVIEWS: Hospital admissions between 1987 and 1992 due to petrol sniffing were compared for Maningrida and a community using only leaded petrol. Admissions from Maningrida decreased significantly following introduction of unleaded petrol (chi 2 on 2df = 22.25, p < 0.001). Lead and hydrocarbon exposures were also compared for three groups from Maningrida (27 sniffers using only unleaded petrol; 15 exsniffers and 13 nonsniffers) and 24 individuals admitted to hospital for petrol sniffing related illness from other communities using only leaded petrol. Median blood lead levels for hospitalized sniffers (using only leaded petrol). Maningrida sniffers (using only unleaded petrol), exsniffers and nonsniffers were 5.06, 1.87, 1.24 and 0.17 microM/L respectively. There were significant differences between blood lead level, delta-aminolevulinic acid dehydratase activity, and free erythrocyte protoporphyrin for sniffers of leaded and unleaded petrol, whereas these indices were not significantly different for current sniffers and exsniffers in Maningrida. Hydrocarbons were only detectable in the blood of active sniffers (toluene < or = 0.5 micrograms/mL; benzene < or = 0.17 micrograms/mL blood; n-hexane not detected). The elimination of tetraethyl lead from petrol resulted in a significant decrease in hospitalization of petrol sniffers.

Evaluation of lead exposure in workers at a lead-acid battery factory in Korea: with focus on activity of erythrocyte pyrimidine 5'-nucleotidase (P5N).

To evaluate lead exposure among lead-acid battery workers in Korea, to evaluate in more detail the erythrocyte pyrimidine 5'-nucleotidase (P5N) test for lead exposure, and to evaluate the abnormal accumulation of erythrocyte pyrimidine nucleotides in the battery workers. Activity of P5N and other biological variables were examined in 66 exposed workers in a lead-acid battery factory and in 26 non-exposed workers in Korea. At the factory the time-weighted average of 13 (72%) of 18 air samples for lead exceeded 0.05 (range 0.012-0.468) mg/m3. Blood lead concentration (PbB) in 39 of the 66 exposed workers was above 40 micrograms/dl, and the mean (SD) PbB in the exposed group was 45.7 (15.7) micrograms/dl. Compared with the nonexposed group, free erythrocyte protoporphyrin in the exposed group was significantly increased, whereas erythrocyte P5N activity and activity of erythrocyte delta-aminolevulinic acid dehydratase (ALAD) were significantly inhibited. Erythrocyte P5N activity had valid correlation biologically with PbB and with other biological variables, such as ALAD activity. In 28 exposed workers, the concentration of erythrocyte pyrimidine nucleotides (uridine 5'-diphosphate-glucose and cytidine 5'-triphosphate) correlated inversely with P5N activity and positively with PbB. These findings show that the depression of erythrocyte P5N activity by lead exposure results in the accumulation of erythrocyte pyrimidine nucleotides. In general, the standard analysis of PbB performed in laboratories around the world remains the most useful index of recent exposure. The results indicate that the erythrocyte P5N activity test provides supporting evidence of lead exposure and shows the effect of lead on nucleotide metabolism.

Acquired hypochromic and microcytic sideroblastic anaemia responsive to pyridoxine with low value of free erythrocyte protoporphyrin: a possible subgroup of idiopathic acquired sideroblastic anaemia (IASA)

Patients with idiopathic acquired sideroblastic anaemia (IASA) usually show macrocytic or normocytic anaemia and increased free erythrocyte protoporphyrin (FEP). The mean cell haemoglobin concentration is normal or slightly low. Here we report a pyridoxine-responsive IASA patient with microcytic and hypochromic anaemia and low FEL level; these features are usually seen in cases of hereditary sideroblastic anaemia. Microcytosis increased during therapy. There may be a subgroup of IASA with microcytic and hypochromic anaemia, low normal FEP and some response to pyridoxine like hereditary sideroblastic anaemia.

Iron status of schoolchildren with varying intensities ofTrichuris trichiurainfection

The relationship between varying intensities of Trichuris trichiura infection and iron status was examined in Jamaican schoolchildren, aged 7 to 11 years. A total of 409 children was identified with T. trichiura (epg > 1200). A control group comprised 207 uninfected children who were matched by school and class to every pair of infected subjects. Blood samples were obtained from 421 children: 264 infected and 157 controls. Compared to the rest of the children, those with heavy infections (epg > 10,000) had significantly lower (P < 0.05) Hb (11.5 +/- 1.3 vs. 12.1 +/- 1.1 g/dl), MCV (78.6 +/- 6.3 vs. 81.2 +/- 5.5 fl), MCH (26.2 +/- 2.9 vs. 27.5 +/- 2.5 pg) and MCHC (33.2 +/- 1.5 vs. 33.9 +/- 1.4 g/dl). Similarly, the prevalence of anaemia (Hb < 11.0 g/dl) amongst heavily infected children (33%) was significantly higher (P < 0.05) than the rest of the sample (11%). These differences remained significant after controlling for confounding variables including socio-economic status, age, gender, area of residence and the presence of Ascaris infections. Differences in red cell count, ferritin, and free erythrocyte protoporphyrin were not statistically significant and showed no association with the infectious load. These results suggest that in the Jamaican children studied, iron deficiency anemia is associated with Trichuris infections over 10,000 epg, but not with less intense infections.

Does Iron Deficiency Raise the Seizure Threshold?

To determine the effect of iron status on the seizure threshold, measures of iron sufficiency were prospectively evaluated in 51 children presenting to a pediatric emergency department with a febrile illness with (26) or without (25) an associated febrile seizure. A higher proportion of children from the febrile seizure group had a family history of mental retardation (5/26 versus 0/25, P = .02) or of previous febrile seizures (10/26 versus 2/23, P = .01). The two groups were otherwise comparable for age, sex, race, family history of afebrile seizures, temperature at presentation, white blood cell count, differential, and vitamin and antibiotic use. Patients with febrile seizures were less frequently iron deficient as defined by a free erythrocyte protoporphyrin level above 0.80 ng/L (2/23 versus 10/25, P < .01), hemoglobin concentration less than 110 g/L (1/26 versus 6/25, P < .03), hematocrit less than 0.30 L/L (0/22 versus 4/25, P < .02), mean corpuscular hemoglobin less than 20 pg (0/25 versus 3/24, P < .04), mean corpuscular volume less than 65 fL (0/26 versus 4/24, P < .02), and platelet count higher than 550 x 10(9)/L (0/26 versus 3/25, P < .04). This association was even stronger when adjusted for differences in family history. None of the patients in the febrile seizure group was being treated for iron deficiency at presentation, whereas three of 25 controls used an iron supplement (P < .04). Iron deficiency may protect against the development of febrile seizures.

Monitoring of iron status and iron supplementation in patients treated with erythropoietin.

Patients receiving erythropoietin therapy require large quantities of iron to keep pace with the demands of the bone marrow during active erythropoiesis. If this iron supply to the marrow is not maintained, the response to erythropoietin is impaired, and indeed iron insufficiency is the most common cause of a poor response to this drug. Iron deficiency may be either absolute, which is defined as a reduction in total body iron stores, or functional, which implies adequate iron stores but a failure to supply available iron to the marrow or a failure in the utilization of this iron in the process of erythropoiesis. The detection of absolute or functional iron deficiency is difficult because there is no absolutely reliable marker of iron status, with the exception of an unequivocally low serum ferritin level. Measurement of serum ferritin and transferrin saturation are the most widely used methods, but both have drawbacks. Monitoring of the percentage of hypochromic erythrocytes in the circulation also seems promising, but the technology is of limited availability, and other methods (eg, monitoring erythrocyte ferritin, free erythrocyte protoporphyrin, and erythrocyte zinc protoporphyrin levels) lack widespread validation. Treatment of iron insufficiency is accomplished by intensifying iron supplementation either orally or intravenously, and in many instances the latter route becomes necessary. The high cost of erythropoietin demands that iron deficiency be screened for on a regular basis and treated to maximize the benefits of this drug.