Erythrocyte disorders in the perinatal period

Flickering of fetal erythrocytes membrane under gestational diabetes observed with dual time resolved membrane fluctuation spectroscopy

The membrane flickering of human fetal red blood cells (RBCs) affected by gestational diabetes mellitus (GDM) was studied with dual time resolved membrane fluctuation spectroscopy (D-TRMFS). This new technique is a modified version of the dual optical tweezers method that has been adapted to measure the mechanical properties of RBCs at two distant membrane points simultaneously. The micro-rheological parameters were obtained from direct membrane flickering measurements, followed by Fourier decomposition and cell membrane model adjustment. Our results show a significant decrease of 6.01 ± 1.19 nm in membrane fluctuations amplitude in healthy fetal, compared with healthy adult RBCs, meanwhile the amplitude in GDM cells increased 3.22 ± 1.10 nm compared with healthy fetal RBCs. Between GDM and healthy fetal RBCs, there are significant differences, especially in the bending modulus. Considering the mean of the two membrane points measured, the tension for GDM RBCs increased by 6.431 ± 3.57 (10-7 [N/m]) compared with healthy fetal RBCs, meanwhile, the bending was increased by 2.483 ± 0.58 (10-19 [J]) in GDM compared with healthy fetal RBCs. These results showed significant increment of 1.23 ± 0.07-fold and 3.29 ± 0.36-fold in tension and bending modulus in GDM, respectively. The strong impact of GDM on bending modulus could be associated with oxidative stress and lipid peroxidation, previously reported in fetal plasma of GDM cases.

Influence of age and sex on osmoscan indies for next-generation osmotic gradient ektacytometry

BACKGROUND AND AIMS

Osmotic gradient ektacytometry is an important method for diagnosis of red blood cell membrane disorders. For interpretation of the osmoscan parameters on the ektacytomety, an age-matched control sample drawn at the same time is recommended for direct comparison. However, this can be challenging for laboratories to fulfil, especially when ektacytometry is performed in children. Therefore, the aim of this study was to evaluate the influence of age and sex on the osmoscan parameters.

MATERIALS AND METHODS

Blood samples from 231 subjects were analyses on a LoRRca MaxSIS. Data were investigated for need of partitioning by age and sex. After outlier detection, reference intervals (RIs) for osmoscan parameters were estimated.

RESULTS

For all parameters except EImin, lower values were observed in infants < 3 month (N = 50) than in all other age group. Hence, RIs were calculated separately for this age group. For EImin, a unified RI was calculated. No difference between sexes was observed for any of the parameters.

CONCLUSION

Lower RIs and a left shift in the osmoscan curves were observed in infants < 3 months compared with older subjects. Hence, age-matched controls are necessary when evaluating ektacytometry in newborns, but can be ignored in older children and adults. This will ease the laboratory workflow when performing ektacytometry.

Congenital Disorders of Red Blood Cells

See Bonus NeoBriefs videos and downloadable teaching slides Understanding the physiologic process of red blood cell development in utero and subsequent erythropoiesis in the neonate is crucial as this determines red blood cell structure and therefore function, which is vital to neonatal health. Infants frequently experience anemia, and special consideration must be given to the evaluation of these infants to determine the correct etiology. Traditionally, anemia is conceptualized in terms of inadequate red blood cell production, increased red blood cell destruction, or whole blood loss. This framework translates well to inherited red blood cell defects, which include genetic abnormalities in bone marrow productivity or structure of the red blood cell membrane, enzymes, or hemoglobin. This article highlights fetal and neonatal erythropoiesis and the underlying etiologies of the inherited red blood cell disorders, as well as reviews the appropriate diagnostic evaluation and next steps in management. It is imperative that neonatal clinicians remain informed about these disorders to enable early recognition and treatment, and ultimately to improve outcomes in affected infants.

Detection of a Hemoglobin Adduct of the Food Contaminant Furfuryl Alcohol in Humans: Levels of N-((Furan-2-yl)methyl)-valine in Two Epidemiological Studies

SCOPE

Furfuryl alcohol is a heat-induced food contaminant, classified as possibly carcinogenic to humans. The proximal carcinogen 2-sulfoxymethylfuran leads to adduct formation in DNA and proteins (e.g., N-((furan-2-yl)methyl)-Val (FFA-Val) in hemoglobin).

METHODS AND RESULTS

This study analyzed human erythrocyte samples from two studies for the presence of FFA-Val: the Risks and Benefits of a Vegan Diet study (RBVD; 72 adults) and the ENVIRonmental influence ON early AGEing birth cohort study (ENVIRONAGE; 100 mother-newborn pairs). In the RBVD study, FFA-Val levels are lower in vegans compared to omnivores (median 13.0 vs 15.8 pmol g^-1 hemoglobin, p = 0.008), and lower in non-smokers compared to smokers (median 14.1 vs 17.0 pmol g^-1 hemoglobin, p = 0.003). In the birth cohort, FFA-Val levels are distinctly higher in maternal compared to newborn samples (median 15.2 vs 2.2 pmol g^-1 hemoglobin, p < 0.001).

CONCLUSIONS

FFA-Val, hitherto detected only in blood samples of mice, is quantifiable in all human samples, indicating a general exposure to furfuryl alcohol. The low adduct levels in blood samples from newborn children suggested that the placenta is a barrier to furfuryl alcohol. Dietary habits and tobacco smoking are two main influencing factors on the formation of FFA-Val, which may be of use as a biomarker of exposure to furfuryl alcohol.

Biological basis of child health 10: function and formation of blood and common blood disorders in children

This article, the tenth in a series on the biological basis of child health, focuses on blood. Blood has a crucial role in the transport of substances such as respiratory gases, nutrients and antibodies, as well as in acid-base balance, fluid balance, blood clotting and the immune system. This article describes the composition, formation and function of blood, outlines normal blood count values and explains the effects of low blood cell counts in children. It also provides an overview of the blood disorders that are commonly seen in children, including anaemia, sickle cell disease, clotting disorders and blood cancers. It is essential for children's nurses to have knowledge and an understanding of blood, including its physiology and pathophysiology, to provide optimal care and support to children and young people and their families.

Levels of the hemoglobin adduct N-(2,3-Dihydroxypropyl)-valine in cord and maternal blood: Prenatal transfer of glycidol in the ENVIRONAGE birth cohort

BACKGROUND

Glycidol, a probable human carcinogen, is a reactive chemical released in the gastrointestinal tract from glycidyl fatty acid esters, which are heat-induced dietary contaminants.

OBJECTIVES

To investigate the prenatal transfer of glycidol, a specific hemoglobin adduct was measured as a biomarker for internal glycidol exposure in paired cord and maternal blood samples.

METHODS

In 100 mother-newborn pairs from the Belgian ENVIRONAGE (ENVIRonmental influence ON AGEing in early life) birth cohort, we studied the correlation between levels of the glycidol-derived hemoglobin adduct N-(2,3-dihydroxypropyl)-valine (2,3-diHOPr-Val) in paired cord and maternal blood samples. The adduct levels were determined after cleavage with a modified Edman degradation by using ultra-high performance liquid chromatography-tandem mass spectrometry and an isotope-labeled reference standard.

RESULTS

2,3-DiHOPr-Val was detectable in all 100 maternal blood samples and in 96 cord blood samples (LOD =0.5 pmol 2,3-diHOPr-Val/g hemoglobin), with medians of 5.4 (range: 2.3-29.2) and 1.6 (range: LOD - 8.9) pmol/g hemoglobin), respectively. In blood samples of mothers who smoked during pregnancy and in the cord blood samples of their newborns (n = 6), the median 2,3-diHOPr-Val levels were 16.7 (range: 6.4-29.2) and 6.2 (range: LOD - 8.6) pmol/g hemoglobin, respectively. The median ratio of 2,3-diHOPr-Val levels of cord to maternal blood was 0.35 (range: 0.19-1.14) (n = 49). The Spearman correlation coefficient between 2,3-diHOPr-Val levels in cord and maternal blood samples was 0.63 (p < 0.001) among all mother-newborn pairs and 0.59 (p < 0.001) among mother-newborn pairs of non-smoking mothers.

DISCUSSION

Maternal data confirm widespread exposure to glycidol, also in non-smokers. Neonatal levels indicate prenatal exposure to glycidol, due to an obviously relatively unhindered passive transfer through the placental barrier. Possible health effects of fetal (and postnatal) glycidol exposure in children may be addressed in epidemiological studies.

Risk Factors Associated with Neonatal Jaundice: A Cross-Sectional Study from Iran

BACKGROUND

Neonatal jaundice is one of the main causes of the patient's admission in the neonatal period and is potentially linked to morbidity.

AIM

This study aimed to determine the possible risk factors for neonatal jaundice.

METHODS

We investigated the case of infants who were admitted to the neonatal department of Ziyaeian hospital and Imam Khomeini Hospital for jaundice. Simple random sampling was used to evaluate variables related to maternal and neonatal predisposing factors based on the medical records and clinical profiles. All variables in this study were analysed using SPSS software.

RESULTS

In this study, about 200 mothers and neonates were examined. Our findings depicted that mother's WBC, Hb, PLT, and gestational age were associated with jaundice (P < 0.05). Furthermore, there were significant relationships between different degrees of bilirubin with TSH, T4 levels and G6PD (P < 0.05). In fact, TSH, T4 levels and G6PD were found to be linked to neonatal hyperbilirubinemia. The risk factors for jaundice in our study population comprise some predisposing factors such as WBC, Hb, PLT, gestational age, TSH, and T4 levels, as well as G6PD. Neonates at risk of jaundice are linked to some maternal and neonatal factors that can provide necessary interventions to reduce the burden of the disease. Therefore, identification of associated factors can facilitate early diagnosis, and reduce subsequent complications.

CONCLUSION

Neonatal jaundice should be considered as the main policy in all health care settings of the country. Therefore, identification of factors affecting the incidence of jaundice can be effective in preventing susceptible predisposing factors in newborns and high-risk mothers.

Oxidative stress, antioxidant capacity, biomolecule damage, and inflammation symptoms of sickle cell disease in children

BACKGROUND

The phenotypic expression of sickle cell disease (SCD) is a complex pathophysiologic condition. However, sickle erythrocytes might be the cause for multiple sources of pro-oxidant processes with consequent linked to chronic and systemic oxidative stress. Herein, we explored the SCD phenomena could be the result in formation of oxidative stress as well as inflammation in children.

MATERIAL AND METHODS

Blood samples of 147 SCD subjects were evaluated. A control group was formed of 156 individuals without SCD. Different oxidative stress markers and inflammatory mediators were measured by using various biochemical techniques. Plasma samples were collected from blood for the measurement of antioxidants and reactive oxygen species (ROS).

RESULTS

The levels of plasma hydroxyl radical (HO•), and nitric oxide (NO) production were higher in SCD children in compared to control groups. The plasma antioxidants capacities such as superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), glutathione peroxidase (GPx) and protein thiol levels were significantly reduced in SCD children. The plasma lipid peroxidation, protein carbonylation, DNA damage markers were significantly altered in different age groups of SCD children. Further, our results showed that SCD children have chronic inflammatory disease due to persistent alteration of haemoglobin content, reticulocyte, total bilirubin, platelet, creatinine, leukocytes, and altered expression of inflammatory mediators in compared to control groups.

CONCLUSION

SCD children have high oxidative stress, and conversely, decreased antioxidant activity. Decrease in antioxidant activity might explained the reduction in lipid peroxidation, protein carbonylation and increased inflammation, which in turn intensify the symptoms of SCD in children.

[Application of systematic etiological analysis in final and differential diagnosis of hereditary hemolytic anemia]

目的

探讨溶血病因系统分析策略在遗传性溶血性贫血病因诊断和鉴别诊断中的应用。

方法

以溶血病因系统分析方法对疑诊溶血性贫血的1 506例患者进行分析。

结果

①1 506例疑诊溶血性贫血患者中，男799例，女707例，中位年龄22岁（4 d~86岁）。涉及三大遗传性溶血病因的患者共1 413例（94%），其中单一病因溶血1 044例（74%），复合型溶血369例（26%）。②在涉及三大遗传性溶血病因的患者中，单一病因血红蛋白病、红细胞膜病及红细胞酶病分别为235例（22%）、656例（63%）及153例（15%）。单一溶血病因与复合溶血病因合并统计，涉及血红蛋白病、红细胞膜病及红细胞酶病分别为489例（29%）、948例（57%）及239例（14%）。上述两种基数统计的三大遗传性溶血病因构成比差异均无统计学意义（P值均>0.05）。③369例（26%）复合型溶血中，不同类型遗传缺陷以血红蛋白病合并红细胞膜病最常见（50%，184/369），亦见于红细胞酶病合并红细胞膜病（18%，66/369），血红蛋白病合并红细胞酶病（4%，13/369）。相同类型遗传缺陷复合型血红蛋白病、复合型膜病、复合型酶病分别为29例（8%）、57例（15%）、9例（2%）。其他复合型溶血、贫血、黄疸占3%（11例），见于合并后天因素、继发因素及其他系统异常。

结论

三大遗传性溶血病因同期检查能对94％的患者进行分类，常见的遗传性溶血病因依次为红细胞膜病、血红蛋白病和红细胞酶病。复合型溶血并非少见，仅单一因素分析不足以提供充分确诊依据。

Ribosomopathies: how a common root can cause a tree of pathologies

Defects in ribosome biogenesis are associated with a group of diseases called the ribosomopathies, of which Diamond-Blackfan anemia (DBA) is the most studied. Ribosomes are composed of ribosomal proteins (RPs) and ribosomal RNA (rRNA). RPs and multiple other factors are necessary for the processing of pre-rRNA, the assembly of ribosomal subunits, their export to the cytoplasm and for the final assembly of subunits into a ribosome. Haploinsufficiency of certain RPs causes DBA, whereas mutations in other factors cause various other ribosomopathies. Despite the general nature of their underlying defects, the clinical manifestations of ribosomopathies differ. In DBA, for example, red blood cell pathology is especially evident. In addition, individuals with DBA often have malformations of limbs, the face and various organs, and also have an increased risk of cancer. Common features shared among human DBA and animal models have emerged, such as small body size, eye defects, duplication or overgrowth of ectoderm-derived structures, and hematopoietic defects. Phenotypes of ribosomopathies are mediated both by p53-dependent and -independent pathways. The current challenge is to identify differences in response to ribosomal stress that lead to specific tissue defects in various ribosomopathies. Here, we review recent findings in this field, with a particular focus on animal models, and discuss how, in some cases, the different phenotypes of ribosomopathies might arise from differences in the spatiotemporal expression of the affected genes.

Summary: This paper reviews recent data on Diamond Blackfan anemia and discusses them in connection with other ribosomopathies.

The Effect of Iron Deficiency on Osmotic Sensitivity of Red Blood Cells from Neonatal Rats and Their Mothers

Iron deficiency during pregnancy has many effects on both the mother and her developing foetus. These can be both short and long term. One effect is an alteration in fatty acid metabolism and we hypothesised that these changes may result in alterations in membrane function and structure. In order to test this hypothesis, we measured osmotic sensitivity in red blood cells isolated from neonates and their mothers at different times following birth. We fed female rats control or iron-deficient diets for 4 weeks prior to mating and kept them on the same diet until term. At that time, we returned one group of deficient dams to the control diet. The others were kept on the same diet. We showed that iron deficiency results in a decrease in osmotic sensitivity in the mothers but not in their neonates. Returning the dams to the control diet resulted in a return of their red cell osmotic sensitivity to control levels. In the neonates, there was no recovery in haematocrit or in any other parameter, though they did not get any worse, in contrast to the pups being suckled by deficient mothers. The data show two things. The first is that following birth, the mother restores her own iron stores at the expense of the pups, and secondly, there are differences in properties and sensitivities between red cells from mothers and their neonates. This latter observation cannot be explained by differences in the membrane fatty acid profiles, which were not significantly different.

Improved harmonization of eosin-5-maleimide binding test across different instruments and age groups

BACKGROUND

The eosin-5'maleimide (EMA) binding test has been studied extensively for the detection of hereditary spherocytosis (HS). Its performance characteristics have been compared to NaCl-based or glycerol lysis-based red cell osmotic fragility tests and cryohemolysis. HS samples are also better identified when both mean channel fluorescence (MCF) of EMA relative to controls and the coefficient of variation (CV) are analyzed.

METHODS

We looked at 65 normal controls including 30 adults 25-65 years old and 35 newborns and 12 HS cases. In addition to the MCF and the CV, we used a side scatter (SSC) vs. EMA fluorescence gate or "footprint" to depict where normal erythrocytes should appear. Erythrocytes that have reduced band 3 protein appear outside of the footprint.

RESULTS

In our study, newborn data did not cluster with the samples from working age individuals. The MCF and the CVs of normal newborns were higher than normal adult group. However, the footprint data of normal samples relative to their controls was around 99.5% for each group, because the footprint was moved to fit the pattern of the normal.

CONCLUSIONS

The inclusion of footprint parameter will help in better standardization as well as implementation of this test across different age groups as well as different instruments. © 2015 International Clinical Cytometry Society.

Neonatal hemolysis and risk of bilirubin-induced neurologic dysfunction

The pathologic phenotype of severe hyperbilirubinemia in the newborn infant is primarily due to excessive bilirubin production and/or impaired conjugation, resulting in an increased bilirubin load. This may, in turn, increase an infant's risk for the development of bilirubin-induced neurologic dysfunction (BIND). The highest-risk infants are those with increased bilirubin production rates due to hemolysis. Several immune and non-immune conditions have been found to cause severe hemolysis, and these are often exacerbated in those infants with perinatal sepsis and genetic predispositions. Therefore, identification of these infants, with novel technologies, is paramount in reducing the incidence of BIND and the long-term neurologic sequelae for these at-risk infants.

Reference intervals and age-related changes for venous biochemical, hematological, electrolytic, and blood gas variables using a point of care analyzer in 68 puppies

OBJECTIVE

To determine the reference interval for various venous analyte concentrations using a point-of-care (POC) analyzer in healthy, 4-84-day-old puppies and identify any age-specific variations in the values as compared with adults.

DESIGN

A prospective cohort study.

SETTING

University teaching hospital.

ANIMALS

Clinically healthy dogs; 68 puppies and 30 adults.

MEASUREMENTS AND MAIN RESULTS

Samples were collected by jugular venipuncture from 68 clinically healthy puppies at 4, 10, 12, 16, 28, 70, 77, and 84 days of age and once each from 30 clinically healthy adult dogs. Blood samples (n = 287) were analyzed within 5 minutes of collection using an automated POC analyzer. Reference intervals for puppies at various ages were estimated using a bootstrap sampling approach. The analytes that were closest to the adult values were pH and bicarbonate. On days 4 and 10 the pH for puppies was higher than the adults while the HCO3 was higher than the adults only on day 4. HCT on day 4 approximated adult values but fell to a nadir on day 28 before rising toward adult levels. At all time points, sodium, chloride, and ionized magnesium concentrations were lower than adult values, and potassium and ionized calcium were higher than adult values. Glucose was similar to adult values on day 4 but was above adult values at all other time points. Blood urea nitrogen (BUN) was higher in puppies until day 28 when it became lower than in adults. BUN levels remained lower than adults through day 84.

CONCLUSIONS

Variations exist between puppies and adults for venous POC analyzer results. Adult reference intervals should not be used for puppies as this might cause misinterpretation of the results.

A Japanese neonatal case of glucose-6-phosphate dehydrogenase deficiency presenting as severe jaundice and hemolytic anemia without apparent trigger

Background

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is rare among Japanese ethnicity although it is known as one of the most common hereditary disorders of erythrocytes, causing intravascular hemolysis. It is well-known that G6PD deficiency may cause hemolysis even in the neonatal period. However, most cases are asymptomatic, and the frequency of severe anemia is low.

Findings

We describe a Japanese male neonatal case of G6PD deficiency presenting as severe, persistent indirect hyperbilirubinemia on day 2 and hemolytic anemia. He was born to non-consanguineous Japanese parents without any family history. We could not find any triggers that could have induced hemolysis during pregnancy.

Conclusions

This case encouraged us to investigate G6PD deficiency as a differential diagnosis of severe neonatal jaundice and hemolytic anemia despite the low prevalence in Japan.

Localization of a major susceptibility locus influencing preterm birth

Preterm birth (PTB) is a complex trait, but little is known regarding its major genetic determinants. The objective of this study is to localize genes that influence susceptibility to PTB in Mexican Americans (MAs), a minority population in the USA, using predominantly microfilmed birth certificate-based data obtained from the San Antonio Family Birth Weight Study. Only 1302 singleton births from 288 families with information on PTB and significant covariates were considered for genetic analysis. PTB is defined as a childbirth that occurs at <37 completed weeks of gestation, and the prevalence of PTB in this sample was 6.4%. An ∼10 cM genetic map was used to conduct a genome-wide linkage analysis using the program SOLAR. The heritability of PTB was high (h(2) ± SE: 0.75 ± 0.20) and significant (P = 4.5 × 10(-5)), after adjusting for the significant effects of birthweight and birth order. We found significant evidence for linkage of PTB (LOD = 3.6; nominal P = 2.3 × 10(-5); empirical P = 1.0 × 10(-5)) on chromosome 18q between markers D18S1364 and D18S541. Several other chromosomal regions (2q, 9p, 16q and 20q) were also potentially linked with PTB. A strong positional candidate gene in the 18q linked region is SERPINB2 or PAI-2, a member of the plasminogen activator system that is associated with various reproductive processes. In conclusion, to our knowledge, perhaps for the first time in MAs or US populations, we have localized a major susceptibility locus for PTB on chromosome 18q21.33-q23.

Managing the difficult case of fetal anemia

OBJECTIVES

To describe a series of complex fetal anemia cases, detail the appropriate investigations and management, and review the literature.

METHODS

Four cases of non-red cell alloimmunization or infective cases of fetal anemia are presented.

RESULTS

Of the four cases presented, one was a neonatal death, one pregnancy was terminated, one case was diagnosed with Diamond Blackfan anemia, and one case was due to recurrent feto-maternal hemorrhages despite negative Kleihauer tests.

CONCLUSIONS

Non-alloimmune causes of fetal anemia can be difficult to manage. Some cases require repeated and frequent intrauterine transfusions. The perinatal mortality and preterm delivery rates are increased, and some cases require considerable long-term treatment including regular transfusions. We present our experience of a series of non-immune fetal anemia managed in a tertiary unit, review the literature, and suggest appropriate management.

Efficacy and tolerability of a prolonged release ferrous sulphate formulation in iron deficiency anaemia: a non-inferiority controlled trial

BACKGROUND

Iron deficiency anaemia (IDA) is the last stage of iron deficiency, consecutive to an imbalance between iron supply through food intake and iron loss through physiological or pathological processes. As well as by haemoglobin levels, IDA is diagnosed by measuring biomarkers of iron stores. Women are most affected by IDA since their teenage years, as menstruation constitutes a chronic iron loss. Oral supplementation with ferrous sulphate is an effective therapy, but gastrointestinal side effects may impair treatment compliance.

METHODS

The present multicentric randomised controlled trial was designed to assess the non-inferiority of a ferrous sulphate prolonged release formulation called V0355 with the referential ferrous sulphate Ferrograd® in a population of Italian women aged 18-50 years diagnosed for IDA. Three hundred and ninety-nine patients were randomised to receive V0355 (80 mg Fe/day) or Ferrograd® (105 mg Fe/day).

RESULTS

After 12 weeks of treatment, the difference in the mean haemoglobin level between the two groups was 0.081 g/dL ([-2.986;1.361], p = 0.54), which confirmed the hypothesis of non-inferiority. All the other biochemical parameters (serum iron, serum ferritin, transferrin, and soluble transferrin receptor) and haematological parameters (erythrocytes count, reticulocytes count, haematocrit, and mean corpuscular volume), as well as patient's anaemia-related symptoms, were not different between treatment groups throughout the study. Furthermore, the incidence of gastrointestinal adverse events of moderate and severe intensity was significantly lower (p = 0.007) in the V0355 group (5.6%) than in the Ferrograd® group (13.9%).

CONCLUSION

V0355 was as efficient as Ferrograd® in the treatment of anaemia and exhibited a better gastrointestinal tolerance profile.

Ribosomal protein L11 mutation in zebrafish leads to haematopoietic and metabolic defects

Mutations in ribosomal proteins are associated with a congenital syndrome, Diamond-Blackfan anaemia (DBA), manifested by red blood cell aplasia, developmental abnormalities and increased risk of malignancy. Recent studies suggest the involvement of p53 activation in DBA. However, which pathways are involved and how they contribute to the DBA phenotype remains unknown. Here we show that a zebrafish mutant for the rpl11 gene had defects both in the development of haematopoietic stem cells (HSCs) and maintenance of erythroid cells. The molecular signature of the mutant included upregulation of p53 target genes and global changes in metabolism. The changes in several pathways may affect haematopoiesis including upregulation of pro-apoptotic and cell cycle arrest genes, suppression of glycolysis, downregulation of biosynthesis and dysregulation of cytoskeleton. Each of these pathways has been individually implicated in haematological diseases. Inhibition of p53 partially rescued haematopoiesis in the mutant. Altogether, we propose that the unique phenotype of DBA is a sum of several abnormally regulated molecular pathways, mediated by the p53 protein family and p53-independent, which have synergistic impact on haematological and other cellular pathways affected in DBA. Our results provide new insights into the pathogenesis of DBA and point to the potential avenues for therapeutic intervention.

Curvilinear mandibular distraction in a patient with mandibulofacial dysostosis associated with Diamond-Blackfan anemia

Diamond-Blackfan anemia (DBA) is a congenital erythroid aplasia or hypoplasia presenting in infancy as a macrocytic anemia. It has been linked to a gene defect resulting in the absence of specific ribosomal proteins that enable erythroid maturation. Treacher Collins syndrome is also associated with defective ribosomal biogenesis. Fifty percent of patients with DBA also present with additional physical abnormalities including growth delay, craniofacial abnormalities, upper limp abnormalities, cardiac defects, urogenital malformations, and cleft palate. Upper airway obstruction may be a complication from craniofacial disorders and may be responsible for life-threatening sleep apnea that may result in pneumonia or respiratory failure. This report is of a patient with DBA who presented at birth with respiratory distress secondary to tongue-based obstruction of the airway due to mandibulofacial dysostosis leading to need for intubation. In an effort to avoid a tracheostomy, the patient underwent bilateral internal mandibular osteodistraction on day 4 of life with a latency period of 0 days and a distraction at a rate of 2 mm/d for 10 days until a class 3 dental occlusion existed with 5 mm of overcorrection. In addition, the patient was born with choanal atresia that was repaired at day 30 of life. After completion of the mandibular distraction, the patient has avoided tracheostomy and is now 6 months of age. Recent polysomnogram has demonstrated no significant apnea or hypopnea.

Rescue of pyruvate kinase deficiency in mice by gene therapy using the human isoenzyme

Human erythrocyte R-type pyruvate kinase deficiency (PKD) is a disorder caused by mutations in the PKLR gene that produces chronic nonspherocytic hemolytic anemia. Besides periodic blood transfusion and splenectomy, severe cases require bone marrow (BM) transplant, which makes this disease a good candidate for gene therapy. Here, the normal human R-type pyruvate kinase (hRPK) complementary (cDNA) was expressed in hematopoietic stem cells (HSCs) derived from pklr deficient mice, using a retroviral vector system. These mice show a similar red blood cell phenotype to that observed in human PKD. Transduced HSCs were transplanted into myeloablated adult PKD mice or in utero injected into nonconditioned PKD fetuses. In the myeloablated recipients, the hematological manifestations of PKD were completely resolved and normal percentages of late erythroid progenitors, reticulocyte and erythrocyte counts, hemoglobin levels and erythrocyte biochemistry were restored. Corrected cells preserved their rescuing capacity after secondary and tertiary transplant. When corrected cells were in utero transplanted, partial correction of the erythrocyte disease was obtained, although a very low number of corrected cells became engrafted, suggesting a different efficiency of cell therapy applied in utero. Our data suggest that transduction of human RPK cDNA in PKLR mutated HSCs could be an effective strategy in severe cases of PKD.