Control of iron metabolism--lessons from neonatal hemochromatosis

Applying an Age-specific Definition to Better Characterize Etiologies and Outcomes in Neonatal Acute Liver Failure

OBJECTIVE

Neonatal acute liver failure (ALF) is a rare disease with high mortality for which no standard age-specific definition exists. To advance the understanding of neonatal ALF, we characterize the etiology, presenting features, treatment, and outcomes in infants within 1 month of life.

METHODS

We performed a single-center 11-year retrospective chart review of neonates ≤30 days of life with ALF as defined by an INR of ≥2.0. Comparisons were made by etiology and survival with native liver (SNL). Estimated survival was performed using the Kaplan-Meier method.

RESULTS

Forty-three patients met inclusion criteria for neonatal ALF. Etiologies included viral infection (23%), gestational alloimmune liver disease with neonatal hemochromatosis (GALD-NH) (21%), cardiac-associated ischemia (16%), other ischemia (14%), genetic etiologies (9%), Trisomy 21-associated myelodysplasia (TAM) (7%), hemophagocytic lymphohistiocytosis (HLH) (2%), and not identified (7%). Infants with viral etiologies had the highest alanine aminotransferase (ALT) at presentation (1179 IU/L, interquartile range [IQR] 683-1585 IU/L) in contrast to low levels in GALD-NH (23 IU/L, IQR 18-64 IU/L). Across all etiologies, only 33% were alive at 1 year. Overall median survival was 74 days; 17 days for viral infection and 74 days for GALD-NH. Among laboratory values at presentation, alpha-fetoprotein (AFP) was significantly higher in patients that survived with their native liver (P = 0.04).

CONCLUSIONS

Overall, outcome for neonatal ALF is poor. Although initial laboratory values can differentiate viral infection or GALD-NH, further studies are needed to identify laboratory parameters that predict SNL by etiology to ultimately improve patient outcomes.

The selfishly selfless placenta

Although iron deficiency continues to pose a problem for pregnant women and fetal development, an incomplete understanding of placental adaptation to limited iron availability has hindered efforts to identify optimal supplementation strategies. In this issue of the JCI, Sangkhae et al. used mouse models and human placentas to explore maternal, placental, and fetal responses to alterations in iron status during pregnancy. The authors identified molecular mechanisms that limit placental ability to upregulate iron transport in the setting of severe iron deficiency and explored a potential marker of placental maladaptation.

Liver Diseases in the Perinatal Period: Interactions Between Mother and Infant

Liver diseases affecting the mother and infant dyad may present in the perinatal period from 20 weeks of gestation to 28 days of life. This review will focus on the current approach to neonatal acute liver failure and the progress made in the diagnosis and management of gestational alloimmune liver disease. It will highlight mother-to-child transmission of viral hepatitis, both management and public health implications. Emerging concepts implicating maternal obesity and nutrition in the development of a rapidly progressive nonalcoholic steatohepatitis phenotype in the offspring will be discussed. Finally, the presentation and management of acute fatty liver of pregnancy and intrahepatic cholestasis of pregnancy, and their impact on the fetus, will be reviewed.

Early Exchange Transfusion to Treat Neonates With Gestational Alloimmune Liver Disease: An 11-Year Cohort Study

OBJECTIVES

Exchange transfusion (ET) and intravenous immunoglobulin are potentially life-saving treatment options in newborns with gestational alloimmune liver disease (GALD). Since 2008, early ET has been the standard of care for symptomatic neonates with suspected GALD in our unit. The present study's aim was to investigate the outcomes of this approach.

METHODS

From 2008 to 2018, all neonates who received ET for suspected GALD were identified, and their clinical course and outcomes were analyzed in a descriptive cohort study. In survivors, liver function parameters before ET and maximum values after ET and at discharge were compared.

RESULTS

During the 11-year period, 12 infants received ET for suspected GALD at a median (range) chronological age of 11 (1-23) days and gestational age of 38 (32-40) weeks. Signs of impaired liver function, most frequently postnatal hypoglycemia, hyperferritinemia, direct hyperbilirubinemia, and coagulopathy, were present in all infants. Survival without a liver transplant in the overall cohort was 10 of 12 (83.3%) and 7 of 9 (78%) in those fulfilling the criteria of acute liver failure. Two patients died, one of them after liver transplantation. Direct bilirubin typically increased after ET, even in survivors. All survivors recovered and were discharged from the pediatric hepatology outpatient clinic after 8 (3-11) months of follow-up.

CONCLUSIONS

In newborns with suspected GALD, a limited diagnostic work-up followed by early ET may lead to favorable outcomes. More data are required to develop an evidence-based clinical approach to GALD.

The Effects of Gestational Alloimmune Liver Disease on Fetal and Infant Morbidity and Mortality

OBJECTIVES

To evaluate pregnancy outcomes in pedigrees of neonatal hemochromatosis to determine the spectrum of gestational alloimmune liver disease (GALD) in a large cohort.

STUDY DESIGN

We prospectively collected data from women with a prior offspring with proven neonatal hemochromatosis between 1997 and 2015 and analyzed pregnancy outcomes.

RESULTS

The pedigrees from 150 women included 350 gestations with outcomes potentially related to GALD. There were 105 live-born infants without liver disease, 157 live-born infants with liver failure, and 88 fetal losses. Fetal loss occurred in 25% of total gestations. Ninety-seven pedigrees contained a single affected offspring, whereas 53 contained multiple affected offspring. Analysis of these 53 pedigrees yielded a per-pregnancy repeat occurrence rate of 95%. Notably, the first poor outcome occurred in the first pregnancy in 60% of pedigrees. Outcomes of the 157 live-born infants with liver failure were poor: 18% survived, 82% died. Of the 134 live-born infants with treatment data, 20 received intravenous immunoglobulin with or without double-volume exchange transfusion of which 9 (45%) survived; 14 infants (10%) received a liver transplant of which 6 (43%) survived.

CONCLUSIONS

GALD is a significant cause of both fetal loss and neonatal mortality with a high rate of disease recurrence in untreated pregnancies at risk. Poor outcomes related to GALD commonly occur in the first gestation, necessitating a high index of suspicion to diagnose this disorder at first presentation.

An immunohistochemical study of placental syncytiotrophoblasts in neonatal hemochromatosis

INTRODUCTION

Neonatal hemochromatosis (NH) is a rare neonatal disorder that results in liver cirrhosis with hemosiderin deposition in the liver and other organs, similarly to hereditary hemochromatosis. Excess iron is transferred from the mother to fetus through the placenta in NH. We examined the expression of iron metabolism-related substances in placental syncytiotrophoblasts (STB) by immunostaining to clarify how the transfer of iron through STB increases in NH.

METHODS

Immunostaining was performed using formalin-fixed, paraffin-embedded sections of placentae from three NH cases, four gestational age-matched controls, and, depending on the antibody examined, five to seven full-term controls. The reactivity of immunostaining was assessed by averages of scores assigned by 3 researchers.

RESULTS

On the microvillar surface of STB, the reactions of the antibodies against transferrin receptor 1 (TFR1), transferrin, ferritin, hepcidin, ferroportin, divalent metal transporter-1 (DMT1), hephaestin, and HFE were stronger in NH than in controls. In the cytoplasm, the reactions of antibodies against TFR1, transferrin, ferritin, hepcidin, DMT1, hephaestin, HFE, and ZIP 14 were stronger in NH than in gestational age-matched controls. Among these reactions, those of anti-TFR1 antibody on the surface of STB in NH was especially marked.

DISCUSSION

In the placenta of NH, increases in expressions of TFR1, transferrin, and ferritin of which those of TFR1 were especially marked, reflect increased iron influx from the mother to fetus. The hepcidin observed on the surface and in the cytoplasm of STB of NH is suggested to be from the mother, possibly to compensate for the decreased fetal liver-derived hepcidin.

Neonatal acute liver failure

Neonatal acute liver failure (NALF) is a rare disease about which there is little published data; however, NALF is an extremely important condition as it is distinct from acute liver failure seen in older children and adults. First, unlike acute liver failure in older patients, NALF can be diagnosed in an infant with cirrhosis. This is due to the fetal-neonatal continuum of liver disease, or the principle that neonatal liver failure may be the result of a liver disease that began in utero. Further differences exist in the mechanism of disease, diagnostic principles, and the common etiologies of NALF when compared with pediatric and adult acute liver failure. This review will address many of the distinguishing features of NALF and focus on the most common etiologies of NALF, including gestational alloimmune liver disease (GALD), the most common cause of NALF. Additionally, this review will provide insight into the pathogenesis, diagnosis, and treatment of this rare condition. Liver Transplantation 22 677-685 2016 AASLD.

Transient neonatal liver disease after maternal antenatal intravenous Ig infusions in gestational alloimmune liver disease associated with neonatal haemochromatosis

OBJECTIVES

Neonatal haemochromatosis is a rare gestational disease that results in severe foetal liver disease with extrahepatic iron overload, sparing the reticuloendothelial system. Recurrence can be prevented with intravenous immunoglobulin (IVIG) infusions during pregnancy, supporting an alloimmune aetiology. The aim of the study was to assess the effect of antenatal treatment with IVIG infusion on the outcome of pregnancies in women with a history of documented neonatal haemochromatosis likely owing to gestational alloimmune disease and to analyse IVIG tolerance.

METHODS

From 2004 to 2012, 8 pregnant women were treated with IVIG at 1 g/kg body weight weekly from 18 weeks' gestation until birth in a prospective multicentre study.

RESULTS

All 8 neonates born to the treated women survived. Five developed mild neonatal liver disease with hepatomegaly (n = 1), hyperechogenic liver (n = 2), abnormal liver function tests (n = 1), raised serum ferritin (n = 3) and α-fetoprotein (n = 5) levels, or mild iron overload on liver magnetic resonance imaging (n = 1). Ferritin and α-fetoprotein levels normalised before 14 days and 2 months, respectively. A per-mother-basis analysis comparing outcomes of treated (n = 8) and untreated (n = 9) gestations showed a significant improvement in the survival of neonates with gestational IVIG therapy (survival 8/8 vs 0/9, P < 0.001). Adverse effects of IVIG infusion occurred in 5 mothers leading to discontinuation of treatment in 1 case. Preterm neonates born before 37 weeks' gestation had a decreased risk of neonatal liver disease (P = 0.04).

CONCLUSIONS

Antenatal treatment with IVIG infusion in women at risk for gestational alloimmune disease recurrence improves the outcome of pregnancies despite mild signs of transient neonatal liver disease.

Iron metabolism in transplantation

Recipient's iron status is an important determinant of clinical outcome in transplantation medicine. This review addresses iron metabolism in solid organ transplantation, where the role of iron as a mediator of ischemia-reperfusion injury, as an immune-modulatory element, and as a determinant of organ and graft function is discussed. Although iron chelators reduce ischemia-reperfusion injury in cell and animal models, these benefits have not yet been implemented into clinical practice. Iron deficiency and iron overload are associated with reduced immune activation, whose molecular mechanisms are reviewed in detail. Furthermore, iron overload and hyperferritinemia are associated with poor prognosis in end-stage organ failure in patients awaiting kidney, or liver transplantation. This negative prognostic impact of iron overload appears to persist after transplantation, which highlights the need for optimizing iron management before and after solid organ transplantation. In contrast, iron deficiency and anemia are also associated with poor prognosis in patients with end-stage heart failure. Intravenous iron supplementation should be managed carefully because parenterally induced iron overload could persist after successful transplantation. In conclusion, current evidence shows that iron overload and iron deficiency are important risk factors before and after solid organ transplantation. Iron status should therefore be actively managed in patients on the waiting list and after transplantation.

De novo duplication of chromosome 16p in a female infant with signs of neonatal hemochromatosis

Reported cases of "pure" duplication of the entire short arm of chromosome 16 (16p) are rare, with only 7 patients described in the literature. We report on a female infant with de novo 16p duplication localized to the short arm of chromosome 6, detected by chromosomal analysis and characterized by array CGH and fluorescence in situ hybridization. This baby girl presented with clinical symptoms characteristic of patients with duplications of the short arm of chromosome 16: psychomotor retardation, constitutional growth delay and specific dysmorphic features, including proximally placed hypoplastic thumbs. In addition, she exhibited evidence of neonatal hemochromatosis as shown by direct hyperbilirubinemia, iron overload and elevated liver enzyme levels. To our knowledge, this is the first report of signs of neonatal hemochromatosis in a patient with 16p duplication.

Neonatal hemochromatosis: management, outcome, and prevention

Neonatal hemochromatosis (NH) is a rare disorder but the most common cause of acute liver failure in neonates. NH is characterized by severe hepatic injury and iron overload and is associated with high perinatal mortality and morbidity rates. NH is often preceded by oligohydramnios and intrauterine growth restriction, suggesting an important impact of NH during fetal life. Stillbirth and prematurity are not uncommon. During the last decade, major discoveries on the etiology of NH have radically changed the management and outcome of this disease. NH is now regarded as an alloimmune disease and is, as such, often referred to as gestational alloimmune liver disease. Antenatal treatment with intravenous immunoglobulins starting at 14 weeks' gestation has been shown to prevent the development of NH in subsequent pregnancies. Postnatal treatment, previously based on the use of anti-oxidants and chelation therapy, has now successfully been replaced by exchange transfusions and intravenous immunoglobulins substitution. This review summarizes the latest discoveries on the etiology of NH and the new recommendations concerning its management and prevention.