Iron concentration and distribution in the newborn liver

Heterogeneous Pathological Changes in Liver Lobes During Liver Disease: A Perspective Review

Liver diseases have a global prevalence of 25%, accounting for 4% of all deaths worldwide, and are associated with a 36% increased risk of fatal and nonfatal cardiovascular events. Metabolic dysfunction-associated steatotic liver disease constitutes the liver expression of metabolic syndrome and represents the primary type of liver disease. Microscopical analysis of biopsies, which allows the evaluation of a small portion of tissue with inferences made to the entire organ, is considered the gold standard for determining the presence of liver diseases. However, potential sampling errors in liver biopsies are conceivable because the obtained tissue represents only a tiny fraction of the entire liver mass and may not accurately reflect the true pathological state. Studies have demonstrated the existence of sampling errors in liver biopsies, particularly concerning the severity of inflammation, degree of fibrosis, and the presence of cirrhosis. Also, clinical studies have shown that histopathological abnormalities are better detected in humans when liver samples are collected from both the right and the left lobes. However, a gap exists in clinical investigation to clarify the role of differences between these lobes in improving the diagnostic and prognostic for liver diseases. Building upon the heterogeneous nature of pathological alterations observed in liver lobes, this perspective review provided recommendations to enhance the precision of diagnosis and prognostic accuracy of liver diseases.

Dietary Approaches to Iron Deficiency Prevention in Childhood-A Critical Public Health Issue

Iron is an essential nutrient, and individual iron status is determined by the regulation of iron absorption, which is driven by iron requirements. Iron deficiency (ID) disproportionately affects infants, children, and adolescents, particularly those who live in areas with unfavorable socioeconomic conditions. The main reason for this is that diet provides insufficient bioavailable iron to meet their needs. The consequences of ID include poor immune function and response to vaccination, and moderate ID anemia is associated with depressed neurodevelopment and impaired cognitive and academic performances. The persistently high prevalence of ID worldwide leads to the need for effective measures of ID prevention. The main strategies include the dietary diversification of foods with more bioavailable iron and/or the use of iron-fortified staple foods such as formula or cereals. However, this strategy may be limited due to its cost, especially in low-income countries where biofortification is a promising approach. Another option is iron supplementation. In terms of health policy, the choice between mass and targeted ID prevention depends on local conditions. In any case, this remains a critical public health issue in many countries that must be taken into consideration, especially in children under 5 years of age.

Dietary Iron Overload Differentially Modulates Chemically-Induced Liver Injury in Rats

Hepatic iron overload is well known as an important risk factor for progression of liver diseases; however, it is unknown whether it can alter the susceptibility to drug-induced hepatotoxicity. Here we investigate the pathological roles of iron overload in two single-dose models of chemically-induced liver injury. Rats were fed a high-iron (Fe) or standard diet (Cont) for four weeks and were then administered with allyl alcohol (AA) or carbon tetrachloride (CCl₄). Twenty-four hours after administration mild mononuclear cell infiltration was seen in the periportal/portal area (Zone 1) in Cont-AA group, whereas extensive hepatocellular necrosis was seen in Fe-AA group. Centrilobular (Zone 3) hepatocellular necrosis was prominent in Cont-CCl₄ group, which was attenuated in Fe-CCl₄ group. Hepatic lipid peroxidation and hepatocellular DNA damage increased in Fe-AA group compared with Cont-AA group. Hepatic caspase-3 cleavage increased in Cont-CCl₄ group, which was suppressed in Fe-CCl₄ group. Our results showed that dietary iron overload exacerbates AA-induced Zone-1 liver injury via enhanced oxidative stress while it attenuates CCl₄-induced Zone-3 liver injury, partly via the suppression of apoptosis pathway. This study suggested that susceptibility to drugs or chemical compounds can be differentially altered in iron-overloaded livers.

Room Temperature Magnetoelectric Sensor Arrays For Application of Detecting Iron Profiles in Organs

Noninvasive measurement of liver iron concentration (LIC) is clinically important. Yet, at the present time, it can only be achieved with SQUID technology. However, SQUID based BLS suffers high costs and cumbersome cryogenic requirements that prevent SQUID BLS from being adopted by clinical applications. Recently, we demonstrated that a single channel ME sensor with piezo-single crystals could detect LIC from only 3cc of mouse liver tissue without any magnetic field shielding. The results demonstrated not only the sensitivity of ME sensor system for LIC but also the feasibility for mapping LIC profiles spatially. This investigation further developed ME sensor arrays, exploiting the compact size and room temperature operation. A Dual-Channel 1-D ME sensor array along the vertical, Z-direction, was developed and shown to be sensitive to the skin-liver distance change which can be utilized to calibrate and eliminate the inter-subject variability of the LIC measurement due to skin-liver distance. With phantom having spatially dependent iron concentrations, the 1-D ME sensor array was capable of mapping the one-dimensional profile of the iron concentration in the horizontal X- and Y-directions. The results of the prototype sensor devices show the feasibility of an array ME-sensors for imaging iron profile.

Maternal Low-Fat Diet Programs the Hepatic Epigenome despite Exposure to an Obesogenic Postnatal Diet

Obesity and metabolic disease present a danger to long-term health outcomes. It has been hypothesized that epigenetic marks established during early life might program individuals and have either beneficial or harmful consequences later in life. In the present study, we examined whether maternal diet alters DNA methylation and whether such modifications persist after an obesogenic postnatal dietary challenge. During gestation and lactation, male Sprague-Dawley rats were exposed to either a high-fat diet (HF; n = 10) or low-fat diet (LF; n = 10). After weaning, all animals were fed a HF diet for an additional nine weeks. There were no differences observed in food intake or body weight between groups. Hepatic DNA methylation was quantified using both methylated DNA immunoprecipitation sequencing (MeDIP-seq) and methylation-sensitive restriction enzyme sequencing (MRE-seq). Overall, 1419 differentially methylated regions (DMRs) were identified. DMRs tended to be located in CpG shores and were enriched for genes involved in metabolism and cancer. Gene expression was measured for 31 genes in these pathways. Map3k5 and Igf1r were confirmed to be differentially expressed. Finally, we attempted to quantify the functional relevance of intergenic DMRs. Using chromatin contact data, we saw that conserved DMRs were topologically associated with metabolism genes, which were associated with differential expression of Adh5, Enox1, and Pik3c3. We show that although maternal dietary fat is unable to reverse offspring weight gain in response to a postnatal obesogenic diet, early life diet does program the hepatic methylome. Epigenetic alterations occur primarily in metabolic and cancer pathways and are associated with altered gene expression, but it is unclear whether they bear consequence later in life.

Rapid postnatal development of myoglobin from large liver iron stores in hooded seals

Hooded seals (Cystophora cristata) rely on large stores of oxygen, either bound to hemoglobin or myoglobin (Mb), to support prolonged diving activity. Pups are born with fully developed hemoglobin stores, but their Mb levels are only 25-30% of adult levels. We measured changes in muscle [Mb] from birth to 1 year of age in two groups of captive hooded seal pups, one being maintained in a seawater pool and one on land during the first 2 months. All pups fasted during the first month, but were fed from then on. The [Mb] of the swimming muscle musculus longissimus dorsi (LD) doubled during the month of fasting in the pool group. These animals had significantly higher levels and a more rapid rise in LD [Mb] than those kept on land. The [Mb] of the shoulder muscle, m. supraspinatus, which is less active in both swimming and hauled-out animals, was consistently lower than in the LD and did not differ between groups. This suggests that a major part of the postnatal rise in LD [Mb] is triggered by (swimming) activity, and this coincides with the previously reported rapid early development of diving capacity in wild hooded seal pups. Liver iron concentration, as determined from another 25 hooded seals of various ages, was almost 10 times higher in young pups (1-34 days) than in yearling animals and adults, and liver iron content of pups dropped during the first month, implying that liver iron stores support the rapid initial rise in [Mb].

Sources of variance in baseline gene expression in the rodent liver

The use of gene expression profiling in both clinical and laboratory settings would be enhanced by better characterization of variation due to individual, environmental, and technical factors. Analysis of microarray data from untreated or vehicle-treated animals within the control arm of toxicogenomics studies has yielded useful information on baseline fluctuations in liver gene expression in the rodent. Here, studies which highlight contributions of different factors to gene expression variability in the rodent liver are discussed including a large meta-analysis of rat liver, which identified genes that vary in control animals in the absence of chemical treatment. Genes and their pathways that are the most and least variable were identified in a number of these studies. Life stage, fasting, sex, diet, circadian rhythm and liver lobe source can profoundly influence gene expression in the liver. Recognition of biological and technical factors that contribute to variability of background gene expression can help the investigator in the design of an experiment that maximizes sensitivity and reduces the influence of confounders that may lead to misinterpretation of genomic changes. The factors that contribute to variability in liver gene expression in rodents are likely analogous to those contributing to human interindividual variability in drug response and chemical toxicity. Identification of batteries of genes that are altered in a variety of background conditions could be used to predict responses to drugs and chemicals in appropriate models of the human liver.

A case of rhesus hemolytic disease with hemophagocytosis and severe iron overload due to multiple transfusions

BACKGROUND

A newborn with cholestatic hepatic disease and hemophagocytic lymphohistiocytosis due to rhesus hemolytic disease (RHD) is reported.

OBSERVATION

A 34 weeks' gestation baby with RHD, who had received multiple intrauterine transfusions (IUT), developed cholestatic hepatic disease and secondary hemophagocytic lymphohistiocytosis (HLH). Her serum ferritin level increased to 5,527 ng/mL, and liver biopsy showed severe iron overload. Treatment with intravenous desferrioxamine resulted in a marked decrease in serum ferritin levels and normalization of liver function

CONCLUSION

We suggest that patients who have undergone IUT be evaluated for hyperferritinemia. If hyperferritinemia is noted, chelation therapy should be considered. As another rare finding, HLH can complicate the course of RHD.

Liver hepcidin and stainable iron expression in biliary atresia

Hepcidin is a proposed mammalian host defense peptide that was identified on the basis of its antimicrobial activity, but it was later shown to be a crucial regulator of iron homeostasis and a mediator of the anemia of chronic inflammation. Hepcidin and stainable iron expression in biliary atresia (BA) were investigated in this study. Fresh liver tissues were obtained from 10 patients in the early stage of BA when they underwent Kasai's procedure, 9 in the late stage of BA when they received liver transplantation and 5 controls receiving liver resection for benign lesions other than cholestasis or fibrosis. Real-time quantitative reverse-transcription PCR (QRT-PCR), immunohistochemical staining and ELISA were performed to gauge hepcidin mRNA and protein expression in liver and plasma. Archival liver specimens from patients in the early and late stages of BA were treated with Perls' acid ferrocyanide technique for hepatic stainable iron. The results demonstrated that liver hepcidin mRNA expression was 100-fold lower in late-stage BA than in the early stage by QRT-PCR. Significantly weaker liver hepcidin immunostaining and lower plasma hepcidin levels were found in late-stage BA than in the early stage. There was also significantly lower stainable iron in the liver of late-stage BA. The major site of stainable iron was in Kupffer cells. The results support a role for hepcidin as a key regulator of mammalian iron metabolism and chronic inflammation, whose expression correlates with the degree of stainable iron in BA.

Determination of trace elements in human liver biopsy samples by ICP-MS and TXRF: hepatic steatosis and nickel accumulation

Human liver biopsy samples, collected from 52 individuals, were analysed by inductively coupled plasma-mass spectrometry (ICP-MS) and total reflection X-ray fluorescence (TXRF) spectrometry in a retrospective study (i.e. patient selection and liver biopsy were not for the purpose of element analysis). The freeze-dried samples (typically 0.5-2 mg dry weight) were digested in a laboratory microwave digestion system and solutions with a final volume of 1 mL were prepared. The concentrations of Cr, Mn, Fe, Ni, Cu, Zn, Rb, and Pb were determined by use of a Thermo Elemental X7 ICP-MS spectrometer. TXRF measurements were performed with an Atomika Extra IIA spectrometer. Yttrium was employed as an internal standard, prepared by dissolution of 5N-purity yttria (Y(2)O(3)) in our laboratory. The accuracy was tested by analysis of NIST 1577a Bovine Liver certified reference material. The concentrations of Fe, Cu, Zn, and Rb determined in human liver biopsy samples were in good agreement with data published by other authors. The distribution of nickel in the samples was surprisingly uneven-nickel concentrations ranged from 0.7 to 12 microg g(-1) (dry weight) in 38 samples and in several samples were extremely high, 36-693 microg g(-1). Analysis of replicate procedural blanks and control measurements were performed to prevent misinterpretation of the data. For patients with steatosis (n=14) Ni concentrations were consistently high except for two who had levels close to those measured for the normal group. As far as we are aware no previous literature data are available on the association of steatosis with high concentration of nickel in human liver biopsies taken from living patients.

Transcriptional profiling of the left and median liver lobes of male f344/n rats following exposure to acetaminophen

The liver is a common organ for transcriptional profiling because of its role in xenobiotic metabolism and because hepatotoxicity is a common response to chemical exposure. To explore the impact that sampling different lobes may have on transcriptional profiling experiments we have examined and compared gene expression profiles of the left and median lobes of livers from male F344 rats exposed to toxic and nontoxic doses of acetaminophen. Transcript profiling using micorarrays revealed clear differences in the response of the left and median liver lobes of F344 rats to acetaminophen exposure both at low doses as well as doses that caused hepatotoxicity. Differences were found in the total number of differentially expressed genes in the left and median lobes, the number and identity of genes that were differentially expressed uniquely only in the left or median lobe, and in the patterns of gene expression. While it is not possible to generalize these results to compounds other than acetaminophen or other strains of rat, these results highlight the potential impact of sampling differences on the interpretation of gene expression profiles in the liver.

New insights into functional aspects of liver morphology

The liver is structurally and functionally complex and has been considered second only to brain in its complexity. Many mysteries still exist in this heterogeneous tissue whose functional unit of the lobule has continued to stump morphologists for over 300 years. The primary lobule, proposed by Matsumoto in 1979, has been gaining acceptance as the functional unit of the liver over other conceptual views because it's based on vessel architecture and includes the classic lobule as a secondary feature. Although hepatocytes comprise almost 80% of the liver, there are at least another dozen cell types, many of which provide "cross-talk" and play important functional roles in the normal and diseased liver. The distribution and functional roles of all cells in the liver must be carefully considered in both the analysis and interpretation of research data, particularly data in the area of genomics and "phenotypic anchoring" of gene expression results. Discoveries regarding the functional heterogeneity of the various liver cell types, including hepatocytes, hepatic stellate cells, sinusoidal endothelia, and Kupffer cells, are providing new insights into our understanding of the development, prevention and treatment of liver disease. For example, functional differences along zonal patterns (centrilobular or periportal) have been demonstrated for sinusoidal endothelium, Kupffer cells, and hepatocytes and can explain the gradients and manifestations of disease observed within lobules. Intralobular gradients of bile uptake, glycogen depletion, glutamine synthetase, and carboxylesterase by hepatocytes; widened fenestrations in centrilobular sinusoidal lining cells; and differences in the components of centrilobular extracellular matrix or function of Kupffer cells have been demonstrated. Awareness of the complexities and heterogeneity of the liver will add to a greater understanding of liver function and disease processes that lead to toxicity, cancer, and other diseases.

Chorioamnionitis-induced changes of fetal extramedullar hematopoiesis in the second trimester of gestation. Is diagnosis from fetal autopsy possible?

Chorioamnionitis, as the most frequent cause of second trimester abortions, is commonly diagnosed by histomorphological examination of placental tissue. We determined whether chorioamnionitis induces a fetal extramedullary hematopoietic response and estimated whether chorioamnionitis can be diagnosed from fetal liver alone. Clinical data and morphological and histological findings of 39 second trimester abortions, caused by chorioamnionitis, were compared with 32 age-matched control cases. Using hematoxylin and eosin staining, naphtol-ASD-chloracetate esterase and "Berliner Blau" reaction, total hematopoiesis, erythropoiesis, myelopoiesis and intracytoplasmatic iron of fetal liver were examined. In the study group, total hematopoiesis was increased compared with the controls (94.9% versus 84.4%). The same was seen in erythropoiesis (69.2% versus 56.2%, P>0.05). Chorioamnionitis resulted in a significant increase of fetal myelopoiesis with clustering of leukocytes in 56.4% (P=0.001). Neutrophiles were located predominantly intrasinusoidal and periportal (74.4%), while an isolated periportal location was often observed in controls (50.0%). Isolated perivenous iron storing was more often seen with chorioamnionitis (28.3% versus 3.1%) and correlated with the increasing severity of chorioamnionitis. It can be stated that infectious diseases, such as chorioamnionitis, increase fetal intrahepatic myelopoiesis as one defense mechanism. The morphology of fetal intrahepatic hematopoiesis and iron storing might also be helpful in the diagnosis of chorioamnionitis, especially when the placenta is not available for examination.

Hepatic failure with neonatal tissue siderosis of hemochromatotic type in an infant presenting with meconium ileus. Case report and differential diagnosis of the perinatal iron storage disorders

We report on a female preterm infant with hepatic failure and neonatal tissue siderosis of hemochromatotic type diagnosed by using both histochemistry and atomic absorption spectroscopy. The infant presented with meconium ileus, signs of rapidly progressive hepatic failure, and hyperferritinemia (7132 ng/ml). Despite surgery and intensive care the infant died 32 days after birth. Postmortem examination showed a wrinkled liver with extensive collapse of the hepatic architecture and regenerating nodules as well as hepatic and extrahepatic iron accumulation of hemochromatotic type, sparing the reticuloendothelial system. Atomic absorption spectroscopy confirmed an increase in the iron content of various organs: liver, heart, pancreas, oral salivary gland, kidney, and adrenal gland. The increase in the iron content of various organs was determined by comparing the analysis of the propositus with those of 5 gestationally age-related preterm infants who had died in the intensive care unit: 2 died of meconium aspiration syndrome, the other 3 of hyaline membrane disease, bronchopulmonary dysplasia, and immaturity, respectively. We also compared the analysis of 15 fetuses having a a condition predisposing to iron accumulation (trisomy 21, trisomy 18, cytomegalovirus, amnion infection syndrome, Rhesus- and ABO-incompatibility, congenital hemolysis, anti-phospholipid syndrome, congenital heart disease). Delta F508, the most frequent mutation seen in cystic fibrosis patients, was excluded by gene sequencing. Different noxae causing iron accumulation in the neonatal period have led to the statement that neonatal hemochromatosis may collect different etiologies, such as metabolic disorders, infections, chromosomal aberrations, and immunological disorders. In this study, we report the singular evidence of neonatal iron accumulation of hemochromatotic type in an infant presenting with meconium ileus and propose a classification of the neonatal disorders associated with iron accumulation.

Hepatic iron storage in very low birthweight infants after multiple blood transfusions

OBJECTIVE

To investigate the effect of multiple blood transfusions on hepatic iron storage in preterm, very low birthweight (VLBW) infants.

METHODS

Seventeen VLBW infants who died within the first six months of life and underwent postmortem examination were studied. Serum ferritin, iron, and total iron binding capacity were measured within the week before the infants' death. Liver iron concentration was quantitatively determined by atomic absorption spectrophotometry and semiquantitatively assessed by histochemical liver iron grading. The clinical characteristics and the iron results were compared between infants receiving < 100 ml of blood (group A) and those receiving >/= 100 ml (group B). Spearman's correlation coefficient was used to evaluate the relation between the volume of blood transfused and serum/liver iron concentrations. Statistically significant variables associated with liver iron concentration were further subjected to multivariate stepwise regression analysis.

RESULTS

Infants in group B had significantly higher serum iron (p < 0.01), serum ferritin (p < 0.01), and liver iron concentration (p < 0.01) than those in group A. The total and net volume of blood transfused were significantly associated with liver iron concentration (p < 0.001, r = 0.86; p < 0.001, r = 0.71 respectively), semiquantitative histochemical liver iron grading (p < 0.001, r = 0.80; p < 0.005, r = 0.71 respectively), and serum ferritin (p < 0.001, r = 0.84; p < 0.01, r = 0.69 respectively). In addition, both liver iron concentration and liver iron grading were found to be significantly associated with serum ferritin (p < 0.001, r = 0.76; p < 0.005, r = 0.68 respectively). Multivariate stepwise regression analysis indicated that the (log) liver iron concentration was significantly associated with the (log) volume of blood transfusion (p < 0.001; regression coefficient 0.39, SE 0.09), after adjustment for gestational age (R(2) = 0.84).

CONCLUSIONS

This study showed a significant positive relation between the volume of blood transfused and the liver iron concentration in preterm VLBW infants. Although the transfusional blood volume correlated closely with the amount of iron deposited in hepatic tissues, clinical manifestations of iron overload were not observed. Carers should be aware of this potential harmful effect before prescribing blood or routine iron supplement to vulnerable preterm infants.

Secondary iron overload

Transfusion therapy for inherited anemias and acquired refractory anemias both improves the quality of life and prolongs survival. A consequence of chronic transfusion therapy is secondary iron overload, which adversely affects the function of the heart, the liver and other organs. This session will review the use of iron chelating agents in the management of transfusion-induced secondary iron overload. In Section I Dr. John Porter describes techniques for the administration of deferoxamine that exploit the pharmacokinetic properties of the drug and minimize potential toxic side effects. The experience with chelation therapy in patients with thalassemia and sickle cell disease will be reviewed and guidelines will be suggested for chelation therapy of chronically transfused adults with refractory anemias. In Section II Dr. Nancy Olivieri examines the clinical consequences of transfusion-induced secondary iron overload and suggests criteria useful in determining the optimal timing of the initiation of chelation therapy. Finally, Dr. Olivieri discusses the clinical trials evaluating orally administered iron chelators.

Elemental composition of anatomically distinct regions of rat liver

Experiments were conducted to test the commonly held assumption that analysis of a portion of rat liver is representative of the elemental concentration of the whole organ. Male Sprague-Dawley rats (initial body weight approximately 250 g) fed a chow diet or weanling male Long-Evans rats (initial body weight approximately 50 g) fed a semipurified diet with or without copper in the mineral premix were sacrificed after 4 wk on their respective diets and livers were dissected into seven portions representing major anatomical divisions of this organ. Elemental analyses by atomic absorption spectroscopy (calcium, magnesium, iron, zinc, copper, manganese), atomic emission spectroscopy (sodium, potassium), or colorimetric assay (phosphorus) demonstrated no statistically significant differences in composition of these nine elements among anatomical regions of liver. Dietary copper deficiency led to equivalently reduced copper concentration in all portions of rat liver and did not cause any other significant alterations in liver composition of these nine elements within the 4 wk of these studies. These results confirm the validity of the common assumption that analysis of a portion of rat liver can be representative of the elemental composition of the whole organ. This conclusion will allow more analyses to be performed on fewer animals, thereby reducing animal use and reagent costs without sacrificing analytical accuracy.

Deferiprone: a review of its clinical potential in iron overload in beta-thalassaemia major and other transfusion-dependent diseases

Patients with beta-thalassaemia and other transfusion-dependent diseases develop iron overload from chronic blood transfusions and require regular iron chelation to prevent potentially fatal iron-related complications. The only iron chelator currently widely available is deferoxamine, which is expensive and requires prolonged subcutaneous infusion 3 to 7 times per week or daily intramuscular injections. Moreover, some patients are unable to tolerate deferoxamine and compliance with the drug is poor in many patients. Deferiprone is the most extensively studied oral iron chelator to date. Non-comparative clinical studies mostly in patients with beta-thalassaemia have demonstrated that deferiprone 75 to 100 mg/kg/day can reduce iron burden in regularly transfused iron-overloaded patients. Serum ferritin levels are generally reduced in patients with very high pretreatment levels and are frequently maintained within an acceptable range in those who are already adequately chelated. Deferiprone is not effective in all patients (some of whom show increases in serum ferritin and/or liver iron content, particularly during long term therapy). This may reflect factors such as suboptimal dosage and/or severe degree of iron overload at baseline in some instances. Although few long term comparative data are available, deferiprone at the recommended dosage of 75 mg/kg/day appears to be less effective than deferoxamine; however, compliance is superior with deferiprone, which may partly compensate for this. Deferiprone has additive, or possibly synergistic, effects on iron excretion when combined with deferoxamine. The optimum dosage and long term efficacy of deferiprone, and its effects on survival and progression of iron-related organ damage, remain to be established. The most important adverse effects in deferiprone-treated patients are arthropathy and neutropenia/agranulocytosis. Other adverse events include gastrointestinal disturbances, ALT elevation, development of antinuclear antibodies and zinc deficiency. With deferiprone, adverse effects occur mostly in heavily iron-loaded patients, whereas with deferoxamine adverse effects occur predominantly when body iron burden is lower.

CONCLUSION

Deferiprone is the most promising oral iron chelator under development at present. Further studies are required to determine the best way to use this new drug. Although it appears to be less effective than deferoxamine at the recommended dosage and there are concerns regarding its tolerability, it may nevertheless offer a therapeutic alternative in the management of patients unable or unwilling to receive the latter drug. Deferipone also shows promise as an adjunct to deferoxamine therapy in patients with insufficient response and may prove useful as a maintenance treatment to interpose between treatments.

Neonatal intrahepatic cholestasis with hepatic siderosis and steatosis

Neonatal intrahepatic cholestasis is a heterogeneous disease of undetermined cause. There is an unreported subset of idiopathic neonatal intrahepatic cholestasis with an unusual histological combination of hepatic siderosis and macrovesicular steatosis. The patients were a 34-day-old female and a 39-day-old male with normal birth weights. Their mothers had received oral iron supplement 4-6 weeks before delivery. The patients had obstructive jaundice noticed at the well-baby clinic at 1 month of life. They had high levels of serum galactose and tyrosine, hyperferritinemia. Urinary organic acid and bile acid analyses were negative, and galactose-1-phosphate uridyltransferase activity in red cells was normal. Liver biopsies showed diffuse iron deposits and macrovesicular fat. By substituting formula milk with lactose-free milk, the patients responded, and had normal biochemical tests within 5 months of life. Follow-up biopsies, at the age of 12 months, showed mild residual fibrosis without iron or fat deposits. They are both well at 3 and 6 years of age, respectively, without biochemical liver dysfunction and neurologic impairment. Prenatal iron-overload might contribute to the pathogenesis of the disease, but further studies are needed to confirm the assumption.

Iron-rich foci in chronic viral hepatitis

Stainable iron in the liver (hemosiderosis) is most commonly seen in individuals with homozygous genetic hemochromatosis, prior transfusion, hemolysis, porphyria cutanea tarda, and chronic alcohol-induced liver disease. In chronic viral hepatitis, however, significant hepatocellular hemosiderosis is uncommon. This report describes unusual foci of hepatocellular hemosiderosis ("iron-rich foci" or IRF) in liver biopsy specimens from three patients with chronic hepatitis with or without cirrhosis (two hepatitis C-related, one hepatitis B-related). IRF present within the lobular parenchyma or cirrhotic nodules contrasted sharply with the immediately adjacent hemosiderin-negative liver tissue. Serum iron indices were abnormal in all three patients, but homozygous hemochromatosis was ruled out based on the hepatic iron concentration and hepatic iron index for each case. These cases highlight the potential for irregular iron storage in chronic viral liver disease and possible confusion with genetic hemochromatosis. The possible pathogenesis of IRF and the relationship of iron storage to the outcome of interferon therapy in chronic viral hepatitis are discussed.

Idiopathic neonatal hepatitis presenting as neonatal hepatic siderosis and steatosis

Idiopathic neonatal hepatitis (INH) is a heterogeneous disease of undetermined cause. We report a retrospective histologic reevaluation of INH. Sixty patients with INH were reviewed along with 32 biliary atresia (BA) patients. Histologic findings, iron and fat deposits, giant cell transformation, portal fibrosis, and bile duct proliferation were semiquantitatively graded from 0 to 4+. Significant histologic findings were defined as > or =2+. Frequencies of patients with significant histologic findings in the INH group were compared with those of the BA group. Among the patients with significant histologic findings, those in the INH group had significantly less iron deposits (P < 0.01), portal fibrosis (P < 0.01), and bile duct proliferation (P < 0.01) than those of the BA group. A combination of significant hepatic macrovesicular steatosis and siderosis was observed in 10 INH patients but not in any BA patient (10/60 vs 0/32, P < 0.05). Without extensive treatment, the 10 INH patients all recovered, and hepatic abnormalities normalized by the age of 12 months. In conclusion, the present study showed that the recognition of hepatic siderosis is helpful to distinguish BA from INH and that in a subset of INH patients hepatic macrovesicular steatosis and siderosis occurs.

Variability in hepatic iron concentration measurement from needle-biopsy specimens

BACKGROUND/AIM

Quantitative measurement of hepatic iron by biochemical analysis of liver biopsy samples is required to assess hepatic iron stores accurately. Cirrhotic livers, however, contain variable amounts of fibrous tissue and the distribution of iron within the hepatic parenchyma is not always uniform. The aim of this study was to assess the variability in hepatic iron concentration measurement from needle-biopsy specimens.

METHODS

The livers from eight patients with cirrhosis selected because of elevated serum ferritin were obtained at the time of liver transplantation (n = 6) or at autopsy (n = 2). Multiple needle biopsies were done, and hepatic iron concentration was measured by atomic absorption spectroscopy. The hepatic iron index was calculated as iron concentration divided by age.

RESULTS

Four cases had a mean hepatic iron index above 2.0, in the range of that reported in patients with homozygous genetic hemochromatosis, whereas the other four had an hepatic iron index of less than 2.0. The intra-individual coefficient of variation for hepatic iron concentration ranged from 11.3 to 43.7%, averaging 24.9%. The coefficient of variation was smaller in biopsy samples > 4 mg dry weight than in samples < 4 mg (19.8% vs 28.6%, p < 0.05). Histological examination of surgical biopsies from these livers showed large amounts of fibrous tissue, and inhomogeneous distribution or iron in the hepatic parenchyma.

CONCLUSIONS

This study demonstrates an important variability in the measurement of hepatic iron content from needle biopsy specimens in patients with severe cirrhosis.

Zinc content and distribution in the newborn liver

The newborn liver is a proven model for the study of liver storage of copper and iron. We analyzed zinc concentration and distribution in the livers of newborns and infants using a systematic tissue-sampling technique. We studied 14 newborns of 26-41 weeks of gestation (WG). One stillborn, and three infants (52-90 days old). At autopsy, a longitudinal liver slice extending from the right to the left lobe was subdivided into 10 samples that were analyzed for zinc concentration by atomic absorption spectroscopy. The mean zinc concentration in the newborn liver was 639 micrograms/g of dry tissue (dt). A striking interindividual variability in zinc liver stores was observed; the hepatic concentration of the metal ranged from 300 to 1,400 micrograms/g dt. We found a correlation between zinc liver content and gestational age. In newborns of 27-32 WG, the hepatic zinc concentration was significantly higher (p < 0.01) than in newborns of 34-41 WG. Zinc stores decreased in the postnatal period; in the infant group, the mean liver zinc concentration was 148 micrograms/g dt. The analysis of zinc concentration in 10 blocks from each liver revealed a regular distribution of the metal, without significant differences between liver lobes. Our data show that the newborn liver can be considered an interesting model for the study of zinc storage, which appears to correlate inversely with gestational age. From a practical point of view, the observed regular distribution of zinc implies that, at least in this model, zinc content determined in a small liver sample is representative of zinc content in the whole liver.

Uneven hepatic iron and phosphorus distribution in beta-thalassemia

BACKGROUND/AIMS

Determination of hepatic iron concentration is crucial in the evaluation of iron-storage disease. Iron content is normally determined in a part of a needle liver biopsy and the value obtained is considered to be representative of the iron concentration in the whole liver. To evaluate the reliability of this procedure, we studied iron distribution in the liver of two beta-thalassemic patients. Since the transport of intracellular iron is mediated by phosphates, we also studied the hepatic phosphorus distribution.

METHODS

At autopsy, a liver slice extending from the left to the right lobe was divided into 51 and 49 samples, respectively. Each specimen was subdivided into two parts: one of them was paraffin-embedded and utilized for the histochemical detection of iron; the second part was analyzed for iron and phosphorus content by induced coupled plasma atomic emission spectroscopy.

RESULTS

The histological picture of both livers was characterized by portal and periportal fibrosis associated with iron storage of different degree, without cirrhosis. The mean iron concentration of the liver was 20,631 +/- 4903 micrograms per g of dry tissue (micrograms/g dt) and 13,901 +/- 1976 micrograms/g dt, respectively. A striking variability in iron content between samples was also found: iron concentration ranged from 11,537 to 32,347 micrograms/g dt in the first case and from 6257 to 16,493 in the second case. We even observed regional differences in iron concentration, with a preferential peripheral accumulation in both cases and a tendency of the left compartment of the liver to accumulate more iron in the first case. Histochemical analyses confirmed the uneven iron distribution even at the acinar level, showing iron mainly being stored in hepatocytes and Kupffer cells of zone 1 of the acinus, with decreasing amounts of iron in zones 2 and 3. The mean hepatic phosphorus concentration was 6662 +/- 1300 micrograms/g dt (range: 4348-9947) and 7502 +/- 986 micrograms/g dt (range: 5844-90,282), respectively. The regional distribution of phosphorus was similar to that observed for iron. A strict correlation between iron and phosphorus content was also observed.

CONCLUSIONS

Our data show that: 1) iron and phosphorus are unevenly distributed in the beta-thalassemic liver, even in the non-cirrhotic stages; 2) a regional pattern of iron and phosphorus distribution is evident, characterized by higher concentrations at the periphery of the liver; 3) the observed uneven distribution of iron and phosphorus implies that their content determined in a small liver sample cannot be considered as absolutely representative of the mean hepatic iron concentration. Therefore, iron concentrations determined in a part of a needle liver biopsy should be interpreted with caution in monitoring the efficacy of the iron-chelating therapy in beta-thalassemic patients.