Dyserythropoietic Anemia Research Articles

CAD mutations and uridine-responsive epileptic encephalopathy.

Unexplained global developmental delay and epilepsy in childhood pose a major socioeconomic burden. Progress in defining the molecular bases does not often translate into effective treatment. Notable exceptions include certain inborn errors of metabolism amenable to dietary intervention. CAD encodes a multifunctional enzyme involved in de novo pyrimidine biosynthesis. Alternatively, pyrimidines can be recycled from uridine. Exome sequencing in three families identified biallelic CAD mutations in four children with global developmental delay, epileptic encephalopathy, and anaemia with anisopoikilocytosis. Two died aged 4 and 5 years after a neurodegenerative disease course. Supplementation of the two surviving children with oral uridine led to immediate cessation of seizures in both. A 4-year-old female, previously in a minimally conscious state, began to communicate and walk with assistance after 9 weeks of treatment. A 3-year-old female likewise showed developmental progress. Blood smears normalized and anaemia resolved. We establish CAD as a gene confidently implicated in this neurometabolic disorder, characterized by co-occurrence of global developmental delay, dyserythropoietic anaemia and seizures. While the natural disease course can be lethal in early childhood, our findings support the efficacy of uridine supplementation, rendering CAD deficiency a treatable neurometabolic disorder and therefore a potential condition for future (genetic) newborn screening.

Response to Alpha-Interferon Treatment of the Congenital Dyserythropoietic Anemia type I in Two Sicilian Beta Thalassemia Carriers.

Congenital dyserythropoietic anemia type I (CDAI) is an autosomal recessive inherited haematological disorder associated with moderate-to-severe anemia characterized by ineffective erythropoiesis with distinct morphological abnormalities in erythroid precursors. We present two case of congenital dyserythropoietic anemia type I in two Sicilian patients heterozygous for β0 39 globin gene cod 39 C>T with marked bone marrow abnormalities, responding to treatment with alpha interferon. The diagnosis was established using routine haematological and biochemical test, light and electron microscopy; molecular analysis of the CDAN1 gene associated to the CDAI disease was performed. The response to the treatment was monitored using the hemoglobin levels, the red cell count, the reticulocyte count and the transfusional requirement. This report points out the usefulness of the treatment with interferon alpha in two Sicilian beta thalassemia carriers, in which the therapy was well tolerated without producing any side effects; in these patients the transfusion requirements after the initiation of interferon therapy decreased.

Clinical Application of Massively Parallel Sequencing in the Diagnosis of Hereditary Hemolytic and Dyserythropoietic Anemias

The Hereditary Hemolytic Anemias (HHAs) are a genetically heterogeneous group of anemias characterized by decreased red blood cell (RBC) survival because of defects in hemoglobin, RBC membrane proteins or enzymes. The diagnosis of this group of disorders is complex and challenging requiring analysis of the morphology of RBCs, hemoglobin electrophoresis, and a battery of phenotypic assays. The phenotypic analysis is often problematic in transfusion dependent patients or at times of presentation with a hemolytic crisis as transfused blood or reticulocytosis confounds diagnostic testing. Molecular genetic testing has grown in popularity in the diagnosis of hereditary hemolytic anemias as it is not affected by transfusions or other clinical variables and provides additional insight into the mechanism of the disease. We have developed a Next Generation Sequencing (NGS) panel for HHA due to RBC membrane disorders and enzymopathies and congenital dyserythropoietic anemias (CDA). CDAs, although collectively rare, are included in the panel as they are occasionally misdiagnosed as hereditary spherocytosis (HS) due to their clinical characteristics of hemolysis, increased osmotic fragility, and splenomegaly albeit with inadequate reticulocytosisWe reviewed the results of 282 sequential HHA/CDA panels testing for patients with suspected HHA or CDA diagnosis, performed and interpreted at Cincinnati Children's Hospital Medical Center between 1/2013-5/2016. Forty-three samples were omitted from the final analysis due to diagnosis of other disorders, indicating that negative results were true-negatives. For the analysis of the remaining 239 panels, all results were reviewed and categorized based on the type of testing ordered: comprehensive HHA/CDA (32 genes), RBC membrane disorders (13 genes), RBC enzyme disorders (14 genes), or CDA (6 genes). The protein-coding exons plus 25 bases of exon-intron junction as well as promoter sequences were included in the design. Genomic DNA was isolated from blood and target regions were enriched using the Haloplex technology. Enriched samples were then sequenced on an Illumina MiSeq benchtop sequencer with 150 base pair, paired-end reads. Sequencing reads were aligned to the human genome reference sequence and analysis of coverage and variants was completed using NextGENe software. All positive findings were confirmed by Sanger sequencing.These 239 panels included 159 (66.5%) comprehensive HHA/CDA panels, 41 (17.2%) RBC membrane disorder panels, 10 (4.2%) RBC enzyme disorder panels, and 29 (12.1%) CDA panels. Overall, a diagnosis was confirmed or identified in 135 (56.5%) patients with specific genotype of hereditary spherocytosis in 52 patients; hereditary elliptocytosis in 15 patients; hereditary pyropoikilocytosis in 7 patients; hereditary stomatocytosis/xerocytosis in 12 patients; South East Asian Ovalocytosis in 1 patient; G6PD deficiency in 15 patients; pyruvate kinase deficiency in 17 patients; other rare RBC enzymopathies in 6 patients; and CDA in 10 patients. The clinical performance of RBC membrane disorder and RBC enzyme disorder panels were comparable between 68-70% in reaching a final diagnosis, while CDA panel confirmed final diagnosis in only 20% of suspected cases. The overall low prevalence, complexity of diagnosis with findings of dyserythropoiesis in bone marrow studies in patients with severe HHA, and evidence of locus heterogeneity in CDA might explain this result. Among patients with suspected RBC membrane disorders, approximately 14% were eventually diagnosed with hereditary xerocytosis (HX). HX diagnosis is critical to make in such patients since splenectomy is contraindicated due to the high risk of life-threatening thrombophilia complications.In more than half (56.5%) of all cases with suspected hereditary hemolytic anemia, genetic testing provided or confirmed the diagnosis and optimized patients' clinical management. Further genetic counseling and testing for other at-risk family members was made possible by achieving molecular diagnosis. Genetic testing substantially altered management in approximately 14% of cases with suspected RBC membrane disorders due to the diagnosis of HX. In conclusion, genetic testing has a significant clinical utility and may facilitate and improve diagnosis, prognosis and management considerations in patients with hereditary hemolytic or dyserythropoietic anemia. [Display omitted] [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Generation and Functional Analysis of Congenital Dyserythropoietic Anemia (CDA) Patient-Specific Induced Pluripotent Stem Cells

The congenital dyserythropoietic anemias (CDAs) are inherited red blood cell disorders representing ineffective erythropoiesis and dyserythropoietic changes in the bone marrow. We recently diagnosed a female patient with undiagnosed congenital anemia as type IV CDA caused by a heterozygous missense mutation of the erythroid-specific transcription factor, KLF1; c.973G>A, p. E325K. Although the mutation has been reported in a male patient characterized as hydrops fetalis, severe neonatal jaundice and transfusion-dependent anemia (Arnaud L et al., Am J Hum Genet, 2010), the proband showed relatively mild phenotype showing moderate dyserythropoietic anemia. In order to investigate the pathological significance of mutant KLF1 during erythroid cell development and differentiation, we generated induced pluripotent stem cells (iPSCs) from peripheral blood of the CDA patient (CDA-iPSCs), and utilized these cells to establish in vitro CDA model for better understanding of its molecular basis. CDA-iPSCs were generated from T lymphocytes in peripheral blood mononuclear cells. Hematopoietic precursors were induced from CDA-iPSCs by embryoid bodies formation. CD34(+) precursor cells were isolated and further cultured in liquid culture with cytokine cocktail (erythropoietin (EPO), interleukin (IL)-3, and stem cell factor (SCF)) for additional 1-3 weeks. Flow cytometric analysis showed that CDA-iPSC-derived cells contained significantly lower percentage of CD235a(+)/CD71(+) erythroid lineage cells than the cells derived from control iPSCs, and lack expression of the adhesion molecule CD44, which is known to be down regulated in peripheral blood erythroid cells of CDA patients (Arnaud L et al., Am J Hum Genet, 2010). In addition, colony-forming unit (CFU) assay indicated that CD34(+) fraction derived from CDA-iPSCs contained a lower number of erythroid colony-forming cells and the most of the cells in these colonies are morphologically abnormal, in comparison with control iPSCs. We next evaluated mRNA expression levels of fetal (HBG1 and HBG2), embryonic (HBE), and adult (HBB) globins, resulting that HBG1 and HBG2 were significantly increased in CDA-iPSCs-derived erythroid lineage cells, whereas HBE showed no significant change and HBB was decreased in CDA-iPSCs-derived erythroid lineage cells. However, BCL11A, one of the target genes of KLF1 and also known as a suppressor of HBG1 and HBG2, was not decreased in the presence KLF1 gene mutation, indicating that elevated HBG1 and HBG2 in CDA-iPSCs-derived erythroid cells was mediated by other mechanism like Leukemia/lymphoma Related Factor (LRF; Masuda T et al., Science, 2016). Here we suggest that our model provides insights on understanding the mechanisms of type IV CDA and the effect of KLF1 gene mutation on clinical phenotype and it would be a useful tool for drug screening and identification of novel biomarker for the rare congenital anemia.Figure 1 Induction of erythroid differentiation from human iPSCsFigure 2 Flow cytometric analysis of erythroid cells induced from CDA-iPSCsFigure 3 RT-PCR analysis of erythroid cells induced from CDA-iPSCs DisclosuresKohara:SBI Pharmaceuticals: Research Funding. Miyamoto:SBI Pharmaceuticals: Research Funding. Tani:Oncolys BioPharma: Equity Ownership; SymBio Pharmaceuticals: Consultancy, Equity Ownership; SBI Pharmaceuticals: Research Funding; Shinnihonseiyaku: Research Funding.

Erythroid-Specific Variant of the Nuclear Exportin Xpo7 Conserved Only in Mammals May Explain Functional Differences Between Mammalian Definitive and Lower Vertebrate (or Primitive) Erythropoiesis

Exportin 7 (Xpo7) was previously found to be crucial for late murine erythroid nuclear maturation when its knockdown significantly inhibited chromatin condensation and ultimate enucleation in a primary mouse erythroblast culture [1]. Additionally, Xpo7 was found to have an erythroid-specific isoform, transcribed from an erythroid-specific transcription start site (TSS) in the first intron of Xpo7 (named Xpo7-1B in contrast to the ubiquitously expressed variant -1A) [1]. Xpo7-1B differs from Xpo7-1B in 8 amino acid residues in the first exon and 9 residues in the 5th exon, and these differences are not conserved either in lower vertebrates or in primitive mouse erythropoiesis. It is intriguing that both lower vertebrate and primitive mammalian erythroblasts do not enucleate.In order to understand the in vivo function of Xpo7 and determine if these differences in the two isoforms confer differential functions to the proteins or are simply regulatory, we examined the definitive fetal liver erythropoiesis (considered adult "stress erythropoiesis") and adult steady state erythropoiesis of transgenic mouse models lacking either Xpo7-1A, Xpo7-1B, or both. We had previously knocked down Xpo7 in zebrafish using morpholinos (zebrafish only express the Xpo7-1A homologue) and found no effect on adult erythroid differentiation or proliferation. Adult Xpo7-1A knockout (KO) mice are born in normal Mendelian ratios, are not anemic, and express normal Xpo7-1B only in the blood. Closer examination reveals that fetal liver erythroid proliferation is actually higher in Xpo7-1A KO mice than either heterozygous (HET) or wild type (WT) while differentiation is normal. The double KO (Xpo7-1AB KO) appears to be embryonic lethal as only 4 live knockout pups were born out of 71 live births and even these 4 pups appear to be partial chimeras. We characterized the Xpo7-1AB HET mice in more detail and fetal liver erythroblasts of HET mice showed normal proliferation and differentiation compared to WT, and adults showed no differences in red blood cell (RBC) counts, hematocrit or hemoglobin. No complete live Xpo7-1AB KO has been born so we are now evaluating embryos at E3, E9.5, and E14.5. Given the possibility of embryonic lethality, in order to evaluate the erythroid-specific isoform Xpo7-1B, we have crossed a mouse floxed for the Xpo7-1B TSS/1st exon with a tamoxifen-inducible Cre-recombinase mouse. These mice have been given tamoxifen after reaching adulthood and we are currently evaluating their hematopoietic parameters. We have also set up HET-HET timed matings and administered tamoxifen to pregnant females to evaluate fetal liver erythropoiesis in Xpo7-1B HET, WT, and KO embryos.Not only will this work further our understanding of the process of global chromatin condensation during erythropoiesis, data from this in vivo study may reveal differences in erythropoiesis between mammals and lower vertebrates, which may also reflect intrinsic differences in mammalian primitive versus definitive erythropoiesis. Based on our in vitro knockdown studies, we anticipate that the phenotype of the Xpo7-1B KO mice may be similar to congenital dyserythropoietic anemia (CDA), a human disorder involving abnormalities in erythroid progenitor chromatin condensation and nuclear membrane substructure, so examination of these mice may also uncover a novel mechanism for this form of ineffective erythropoiesis.[1] Hattangadi, SM, et al. Blood (2014) 124, 1931-40. DisclosuresNo relevant conflicts of interest to declare.

Comparison of Clinical Diagnosis for Hereditary Spherocytosis with Molecular Diagnosis By Multi-Gene Target Sequencing in Korea

Background: Hereditary spherocytosis (HS) is the most common cause of hereditary hemolytic anemia. Current tests used to diagnose HS focus on the detection of hemolysis or indirectly assess protein defects. Direct methods to detect protein defects are complicated and difficult to implement. Recent next-generation sequencing (NGS) methods enable large-scale gene mutation analyses to be used for such diagnoses. In this study, we investigated the patterns of genetic variation associated with HS among the patients diagnosed with HS clinically. Specifically, we analyzed mutations in red blood cell membrane protein-encoding genes (17 genes) in context with 5 genes for the differential diagnosis (thalassemia, congenital dyserythropoietic anemia, paroxysmal nocturnal hemoglobinuria) in Korean HS.Methods: In total, 60 patients diagnosed with HS were enrolled in this study. Targeted sequencing of 43 genes (17 membrane protein-encoding genes, 20 enzyme-encoding genes, and 6 additional candidate genes) was performed using the Illumina HiSeq platform and variants were called according to a data-processing pipeline.Results: Of the 60 patients, 50 (83%) had one or more significant variants in a membrane protein encoding genes. A total of 54 significant variants (8 previously reported and 46 novel) were detected in 6 membrane protein-encoding genes; SPTB, ANK1, SPTA1, SLC4A1, EPB41, and EPB42. The most variants (28/60 patients) were detected in SPTB. Interestingly, concurrent mutations of genes encoding enzymes (ALDOB, GAPDH, and GSR) were detected along with mutations of membrane encoding genes. One patient diagnosed with HS harbored mutation of G6PD without mutation of HS related genes. Additionally, UGT1A1 mutations were present in 5 patients. Positive rate of osmotic fragility test was 86% among patients with HS related gene mutations.Conclusion: These results clarify the molecular genetic analysis is required for the accurate diagnosis of HS. About 17% of patients who were clinically diagnosed as HS revealed discrepancy with molecular diagnosis. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Iron Overload and Cytokine Serum Levels in Congenital Hemolytic Anemias

▪Background: Congenital hemolytic anemias (CHAs) are a heterogeneous group of inherited RBC disorders including membrane and enzyme defects and dyserythropoietic anemias. Iron overload is a well recognized complication of hereditary hemoglobinopathies, both in transfusion-dependent and independent cases. However, little is known in congenital hemolytic anemias, with the exception of anecdotic reports in pyruvate kinase deficiency and dyserythropoietic anemias.Aim: to describe the clinical and hematological features at diagnosis and enrolment, to investigate iron overload by hepatic and cardiac T2* MRI, and to study inflammatory/regulatory cytokine profiles (IL-6, TNF-alpha, IFN-gamma, IL-10, IL-17) and hepcidin levels in patients with CHAs. Confounding factors such as hemocromatosis genotyping, metabolic syndrome, and hepatic viral profile were also considered.Methods: Between July 2015 and April 2016, 38 patients were enrolled (13 hereditary spherocytosis -HS, 3 hereditary stomatocytosis - HSt, 8 congenital dyserythropoietic anemia type II - CDAII, 13 pyruvate kinase deficiency - PKD, 1 glucose-phosphate isomerase deficiency). HS cases were enrolled on the basis of ferritin >300 ng/mL at diagnosis. Cytokine levels were detected in serum by ELISA. Comparisons were made by Students T test (continuous) and Fisher’s exact test (categorical), and correlations by Pearson’s linear coefficient.Results: The main clinical and hematological findings are shown in table. Median Hb values progressively decreased in the 4 groups considered, being close to normal in HS and moderately reduced in CDAII patients, whereas hemolytic parameters were comparable among groups. Consistently with clinical severity, ferritin values were particularly high in CDAII (together with transferrin saturation-TfS) and PKD patients, notwithstanding chelation in about half cases of both groups. Of note, only 2 PKD patients were transfusion-dependent, suggesting that other factors are involved in iron overload. Splenectomy had been performed in 17/38 (44.7%), mainly CDAII. Liver iron concentration (LIC) showed a great heterogeneity in all groups, with a trend towards higher values in CDAII; 16/36 (44%) patients had a LIC>4 mg/g DW (23%, 33%, 38% and 88% in HS, HSt, PKD and CDAII, respectively). Cardiac T2* value was normal in all subjects, with the exception of a HS and a CDAII case. Regarding possible cofactors, 12/16 displayed at least one of the following: 1 homozygous for HFE C282Y and 1 for H63D mutations, 3 HCV+, 4 BMI>25, 2 alcohol abuse, 3 heterozygous for HFE mutations. The following positive correlations were observed at enrolment: LIC and ferritin (r=0.68, p<0.05), LIC and TfS (r=0.34, p=0.05), and cardiac T2* and TfS (r=0.34, p<0.05). Moreover Hb values at diagnosis negatively correlated with LIC (r=0.37, p<0.05). Interestingly, among the 28 cases with ferritin <800 ng/mL, 10 (36%) displayed liver iron overload (LIC>4), of whom 5 with the above listed cofactors. As regards cytokine levels, IL-10 was significantly increased in HS, PKD and CDAII groups compared with normal cases; TNF-alpha was decreased in HS and PKD, and IFN-gamma increased in HS and CDAII. Ferritin values were positively correlated with IL-6 and IFN-gamma, and TfS negatively with IL-6 (r= -0.38, p<0.05). Hepcidin values were slightly increased in CHAs compared with normal controls, and correlated positively with ferritin (r=0.33; p<0.05), and negatively with TfS (r= -0.56; p<0.001). Finally, hepcidin levels were positively correlated with IL-6 (r=0.62; p<0.001), and negatively with IFN-gamma (r=0.3; p<0.05).Conclusion: Iron overload is highly prevalent in CHAs, particularly in PKD and CDAII, is independent from transfusion support, and is also observed in cases with ferritin <800 ng/mL. T2* MRI is the gold standard approach to evaluate iron overload in CHAs (as in other congenital anemias) and its use is advisable, particularly in the presence of cofactors, for early chelation. Cytokine studies suggest the existence of a positive loop among ferritin, hepcidin, and inflammatory cytokines such as IL-6 and IFN-gamma, and of a negative loop among TfS, hepcidin, and the same inflammatory cytokines. These findings disclose important hints to understand the multiple biological mechanisms of iron overload, and support the rationale for new emerging therapies. [Display omitted] DisclosuresBarcellini:Agios: Consultancy.

Evaluation of Liver Iron Deposition in Transfusion-Dependent Patients By Dual-Energy CT

▪[Introduction]The launch of the oral iron chelator "Deferasirox" has improved the outcomes of blood transfusion-dependent patients with iron overload in the last decade. Although serum ferritin (SF) remains the mostly commonly used metric to monitor body iron stores for decisions regarding the indication of iron chelate therapy, it is known to be affected by many factors. The liver iron concentration (LIC) is considered to be an indicator of total body iron stores, and the MR imaging-based R2 technique is the standard non-invasive technique used to evaluate LIC. However, this technique is not used in every institution due to some limitations such as its high cost and the requirement for special software. Although the application of CT, which is easy to use and inexpensive, needs to be considered for the evaluation of LIC, the use of conventional single energy CT (SECT) to measure LIC is also limited by normal variations in CT attenuation, predominantly in patients with mild iron overload. Moreover, SECT fails to detect iron in fatty livers, which has an inverse effect on attenuation by lowering CT numbers. Dual-energy CT (DECT) is a technique that is employed to obtain precise information on tissue composition and may be useful for monitoring LIC. It is based on substances showing different densities with two different energies, with each substance displaying its own energy-dependent change in CT attenuation. The role of DECT in monitoring LIC has not yet been clarified in blood transfusion-dependent patients with iron overload. We herein evaluated iron deposition in the livers of blood transfusion-dependent patients using DECT.[Patients and Methods]Seventeen blood transfusion-dependent patients underwent liver DECT using a dual-source 128-slice CT system, and SF levels were measured at same time. DECT images were acquired using a tube voltage pair of 140 kV and 80 kV or 140 kV and 100 kV, and the three-material decomposition of fat, soft tissue, and iron.[Results]The median age of patients was 52 years (range, 25 to 66), and 8 patients were male. Eight patients with AML, 3 with MDS, and 1 each with ALL, lymphoma, aplastic anemia, Evans syndrome, congenital dyserythropoietic anemia, and chronic renal failure underwent DECT. Nine patients had undergone stem cell transplantation before DECT, and 3 were receiving iron chelate therapy. The total number of units of blood transfused was available in 11 out of 17 patients. The median number of units given was 66 (range, 36 to 150). The median SF level was 2346 ng/ml (range, 569 to 7875). We divided patients into three groups based on SF levels: high >3000 ng/ml, intermediate 1000~3000 ng/ml, low <1000 ng/ml. Five patients were classified into the high SF group (range, 3765-7875 ng/ml), 8 into the intermediate SF group (1645-2916), and 4 into the low SF group (569-1240). Four patients in high, 4 in the intermediate, and 2 in the low SF groups showed diffuse iron deposition in the liver on DECT images. One patient in the high, 2 in the intermediate, and 2 patients in the low SF groups showed focal iron deposition in the left lobe of the liver. On the other hand, two patients in the intermediate SF group did not show iron deposition on DECT images. We then divided patients into two groups based on the number of units of blood transfused: 6 patients were classified into the high unit group (range, 66-150 units), and 5 into the low unit group (36-60). Four patients in the high unit and 3 in the low unit groups showed diffuse iron deposition in the liver on DECT images. Two patients in the high unit and 1 in the low unit groups showed focal iron deposition in the left lobe of the liver. One patient in the low unit group did not show iron deposition.[Conclusion]Discrepancies between SF levels and DECT images indicate that DECT is a useful technique for the accurate evaluation of LIC, and the detection of focal iron deposition in the liver may be useful for optimizing iron chelation therapy. DisclosuresNo relevant conflicts of interest to declare.

CD44 as a Potential Screening Marker for Preliminary Differentiation Between Congenital Dyserythropoietic Anemia Type II and Hereditary Spherocytosis.

Bone marrow examination has been the confirmatory test for congenital dyserythropoietic anemia type II (CDAII). Occasional spherocytes on peripheral blood smear can confound the diagnosis. Since a screening test is still unavailable, we explored the feasibility of using flow cytometry as a preliminary screening method. Thirteen monoclonal antibodies with specificities for eight erythrocyte membrane proteins were used in FACS analysis to probe the cellular features of red cells from CDAII, normal adults, hereditary spherocytosis (HS), and cord red cells. Confocal microscopy was performed on normal and CDAII to determine the overall distribution of CD44 and CD47. Their expression levels on cultured erythroblasts were also analyzed. The densely stained band 3 as seen in CDAII in gel electrophoresis was also obtained for Dantu phenotype. Likewise analysis of CDAII cases (n = 26) using the eosin-5'maleimide (EMA) binding test found 57% of patients giving results either positive or in the grey area for HS. Enhanced fluorescence of CD44 was detected in 96% of the CDAII patients, and anti-CD47 binding was also elevated to a lesser degree. Although RNA expressions of CD44 and CD47 in the cultured erythroblasts of normal controls and CDAII were similar, confocal microscopy revealed more CDAII red cells giving elevated fluorescence than normal red cells. A distinction between CDAII and HS can be made using the EMA Binding test and anti-CD44 binding. Confirmation of CDAII can subsequently be made based on clinical presentation together with either bone marrow examination or DNA sequencing of SEC23B. © 2016 International Clinical Cytometry Society.

Proton pump inhibitors use suppresses iron absorption in congenital dyserythropoietic anemia

ABSTRACTCongenital dyserythropoietic anemia type I (CDA I) is associated, as other anemic noninflammatory states, with ineffective erythropoiesis and increased iron absorption, which may lead to complication of iron overload. The latter complication requires iron-chelating therapy, which may be associated with adverse effects and toxicity. Gastric acid production is known to be an important factor that facilitates non-heme iron absorption. The purpose of this study was to examine whether treatment with proton pump inhibitors (PPIs) can decrease iron absorption in patients with CDA I. Eight CDA I patients (4 boys) aged 12–18 years with mild iron overload (not yet requiring chelating therapy) received 20 mg/d omeprazole for 6 months. Blood samples were obtained for ferritin, C-reactive protein, hemoglobin, calcium, and magnesium at baseline, at the end of months intervention and 6 months after its cessation. The mean ferritin level decreased from 585 ± 180 ng/ml at baseline to 522 ± 172 ng/ml at the end of 6-month treatment and 660 ± 256 ng/ml 6 months after cessation of omeprazole treatment (p = 0.009). Omeprazole treatment caused a nonsignificant reduction in the mean iron level (iron 159 ± 42, 136 ± 54,167 ± 34 µg/dl, p = 0.302). However, mean hemoglobin level was mildly but significantly reduced (Hg 10.0 ± 0.8, 9.55 ± 1.0, 10.4 ± 10.7 g/dl, p = 0.002). No adverse effects were reported. Our investigation suggests that administration of PPI to patients with CDA I may reduce iron absorption and may lower iron overload and the need for chelation therapy.

Clinical and genetic association, radiological findings and response to biological therapy in seven children from Qatar with non-bacterial osteomyelitis.

We aim to report the clinical manifestations, genetic testing results, magnetic resonance imaging (MRI) findings and biologics used in the management of non-bacterial osteomyelitis in our center. We conducted a retrospective review of medical records. A previously proposed classification was implemented as follows: chronic recurrent multifocal osteomyelitis (CRMO), chronic non-bacterial osteomyelitis (CNBO) and acute non-bacterial osteomyelitis. Four females and three males with a median age at presentation of 6 years (6 months-14 years) presented with arthralgia (7/7), back pain (4/7), arthritis (4/7) and bone pain (2/7). Six patients had CRMO and one patient had CNBO. Genetic testing revealed an apparent homozygote p.S734L LPIN2 mutation in two siblings, a heterozygote p.M694V MEFV mutation in one patient with familial Mediterranean fever and heterozygote p.Q219H PSTPIPI variant of unknown significance in one patient. The most common lesions on MRI involved the tibia (6/7), talar bones (5/7), fibula (4/7) and sacroiliac joints (4/7). Three patients received infliximab. Two are in remission after 2 and 5 years, and the third was advanced after 5 years to canakinumab. Two other patients received canakinumab first. One patient with Majeed syndrome and dyserythropoietic anemia exhibited evidence of improvement, and one had partial improvement and was then treated with infliximab. Non-bacterial osteomyelitis may coexist with other autoinflammatory diseases. MRI remains a favorable diagnostic tool and genetic testing may have a limited role in selected cases. Infliximab and canakinumab are associated with variable outcomes, and 6-week or less dosing intervals for both medications may be more effective.

A case of genetically diagnosed congenital dyserythropoietic anemia

A case of genetically diagnosed congenital dyserythropoietic anemia

Fibromuscular Dysplasia Complicated With Cerebral Stroke in a Child With Congenital Dyserythropoietic Anemia Type II

Congenital dyserythropoietic anemia type II belongs to a subtype of bone marrow failure syndrome, which is characterized by monolineage involvement and typical morphologic abnormalities in erythroid precursor cells resulting in different degrees of hyporegenerative anemia. Moreover, reticulocytosis, which is not corresponding to the degree of anemia, with jaundice and splenomegaly are major diagnostic criteria. Causative gene is located at SEC23B. Although stroke among children is rare, it can cause significant morbidity and mortality. Herein we present a 3-year-old male with congenital dyserythropoietic anemia type II who presented with stroke-like symptoms, and was diagnosed with fibromuscular dysplasia.

An Unusual Hydrops Fetalis Associated with Compound Heterozygosity for Krüppel-like Factor 1 mutations

Hydrops fetalis is commonly due to Hb Bart’s (γ4) disease in South East Asia. Here, we report an unusual case of hydrops fetalis due to congenital dyserythropoietic anemia (CDA) associated with compound heterozygosity for Krüppel-like factor 1 (KLF1) gene mutations. Fetal cardiomegaly was first detected on routine mid-trimester scan in a pregnant woman with normal mean corpuscular volume (MCV) and Rhesus positive status. The fetus subsequently developed hydrops fetalis, and cordocentesis showed severe fetal anemia with a hemoglobin (Hb) level of 3.4 g/dL. Common causes of fetal anemia including Hb Bart’s disease, parvovirus infection, and red cell antibodies were excluded. In view of the marked increase in erythroblasts at various stages of erythropoiesis, the diagnosis of CDA was suspected. We screened the couple for previously reported KLF1 gene mutations, showing that the mother was heterozygous for the c.525_526insCGGCGCC, p.Gly176Argfs*179 mutation, and her husband heterozygous for c.1012C>A, p.Pro338Thr mutation. The fetus was a compound heterozygote for these two KLF1 mutations. After counseling, repeated intrauterine transfusions were given at 27, 29, and 34 weeks’ gestation; the hydrops fetalis was resolved. The baby was delivered at 34 weeks’ gestation and required monthly blood transfusions but was otherwise thriving. Bone marrow aspiration at 10 months of age showed the features of ineffective erythropoiesis, compatible with CDA. In conclusion, hydrops fetalis can rarely be due to CDA associated with a compound heterozygous mutation for KLF1 gene mutations, and be managed by repeated intrauterine transfusions. Our present report adds to the wide clinical spectrum of KLF1 mutations.

Can mutations in the gene encoding transcription factor EKLF (Erythroid Krüppel-Like Factor) protect us against infectious and parasitic diseases?

Transcription factor EKLF (Erythroid Krüppel-Like Factor) belongs to the group of Krüppellike factors, which regulate proliferation, differentiation, development and apoptosis of mammalian cells. EKLF factor is present in erythroid cells, where it participates in regulation of hematopoiesis, expression of genes encoding transmembrane proteins (including blood group antigens), and heme biosynthesis enzymes. It is also a key factor in downregulation of γ-globins and activation of β-globin gene expression. The EKLF factor consists of two domains: proline-rich transactivation domain and DNA-binding domain containing three zinc finger motifs, which recognize DNA. EKLF can act as a transcription activator (for example in the case of β-globin gene) or repressor, which depends on the type of posttranslational modification (phosphorylation, SUMOylation, ubiquitination and acetylation). Mutations in the gene encoding EKLF may cause hemoglobinopathies, such as hereditary persistence of fetal hemoglobin and β-thalassemia intermedia, and congenital dyserythropoietic anemia type IV, which is a hematopoietic disorder. These changes may impede invasion of red blood cells by malaria merozoites and cause faster removal of invaded erythrocytes. In addition, mutations in KLF1 may decrease the number of erythrocyte surface antigens that belong to blood group systems such as MN, P1PK, Lutheran, Duffy, Diego and OK. Such antigens can be receptors for protozoans (such as Plasmodium falciparum or Plasmodium vivax), bacteria (like uropathogenic strains of Escherichia coli, Neisseria meningitidis), and toxins (Shiga toxins), which may cause several dangerous diseases including malaria, pyelonephritis, hemorrhagic colitis, hemolytic uremic syndrome (HUS) and meningitis. Here, we propose a hypothesis on possible liaisons between mutations in the gene encoding EKLF and resistance to pathogens.

Hematology – A diagnostic tool in cases of splenomegaly

Objective: To study hematological profile in patients with clinically palpable spleen and to find out the role of hematological investigations as a diagnostic tool in elucidating etiopathogenesis of splenomegaly. Materials and methods: This cross-sectional study was conducted on 50 patients at a teaching hospital from Aug 2011 to 2013. Detailed clinical history including name, age, sex, chief complaints, clinical findings, X-ray and USG (if done) were noted. Grading of splenomegaly was done by Hackett's classification. Laboratory tests including peripheral blood smear, complete blood count and bone marrow examination (if required) were performed. Results: In the present study, maximum numbers of patients were males in the age group of 0-15 years. The commonest cause of splenomegaly found was acute leukemia followed by malaria, hemolytic anemia, chronic myeloid leukemia, liver cirrhosis and infections. Hematological causes were the most common etiology of splenomegaly in this study. The commonest grade of splenomegaly was I and II (mild). There was also a case of congenital dyserythropoietic anemia type I (CDA), a rare autosomal recessive disorder. We also came across one case of plasmodium falciparum malaria with no evidence of parasite on peripheral blood smear which called for bone marrow study. Conclusion: Splenomegaly is a subject of considerable clinical concern as spleen is not palpable under normal circumstances. When palpable, it may be associated with serious disorders from which no age is exempted. Thus, hematological evaluation becomes necessary to understand the etiopathogenesis of splenomegaly.

Analysis of a cohort of 101 CDAII patients: description of 24 new molecular variants and genotype-phenotype correlations.

Congenital dyserythropoietic anaemia type II (CDAII) is a rare autosomal recessive disease characterized by ineffective erythropoiesis, haemolysis, erythroblast morphological abnormalities, hypoglycosylation of some red blood cell membrane proteins, particularly band 3, and mutations in the SEC23B gene. We report the analysis of 101 patients from 91 families with a median follow-up of 23years (range 0-65); 68 patients are newly reported. Clinical and haematological parameters were separately analysed in early infancy and thereafter, when feasible. Molecular analysis of the SEC23B gene confirmed the high heterogeneity of the defect, leading to the identification of 54 different mutations, 24 of which are newly described. To evaluate the genotype-phenotype correlation, patients were grouped according to their genotype (two missense mutations vs. one missense/one drastic mutation) and assigned to two different severity gradings based on laboratory data and on therapeutic needs; by this approach only a weak genotype-phenotype correlation was observed in the analysed groups.

Congenital dyserythropoietic anemia associated to a GATA1 mutation aggravated by pyruvate kinase deficiency

Congenital dyserythropoietic anemia associated to a GATA1 mutation aggravated by pyruvate kinase deficiency

Pharmacological Targeting of the Hepcidin/Ferroportin Axis.

The iron regulatory hormone hepcidin limits iron fluxes to the bloodstream by promoting degradation of the iron exporter ferroportin in target cells. Hepcidin insufficiency causes hyperabsorption of dietary iron, hyperferremia and tissue iron overload, which are hallmarks of hereditary hemochromatosis. Similar responses are also observed in iron-loading anemias due to ineffective erythropoiesis (such as thalassemias, dyserythropoietic anemias and myelodysplastic syndromes) and in chronic liver diseases. On the other hand, excessive hepcidin expression inhibits dietary iron absorption and leads to hypoferremia and iron retention within tissue macrophages. This reduces iron availability for erythroblasts and contributes to the development of anemias with iron-restricted erythropoiesis (such as anemia of chronic disease and iron-refractory iron-deficiency anemia). Pharmacological targeting of the hepcidin/ferroportin axis may offer considerable therapeutic benefits by correcting iron traffic. This review summarizes the principles underlying the development of hepcidin-based therapies for the treatment of iron-related disorders, and discusses the emerging strategies for manipulating hepcidin pathways.

Morbidity and mortality of adult patients with congenital dyserythropoietic anemia type I.

Congenital dyserythropoietic anemia type I (CDAI) is a rare autosomal recessive disease characterized by macrocytic anemia, ineffective erythropoiesis, and secondary hemochromatosis. To better define the natural history of the disease among adult patients, we studied 32 Bedouin patients (median age 34 yr; range 21-60) all carrying the same CDAN1 founder mutation. Follow-up studies included complete blood count, blood chemistry, abdominal ultrasound, echocardiography, and T2*MRI. Main complications were due to anemia and ineffective erythropoiesis [osteoporosis (8/9, 89%), cholelithiasis (21/30, 70%), pulmonary arterial hypertension (PAH) (6/25, 24%)] and iron overload [hypothyroidism (9/24, 38%), and diabetes mellitus (6/32, 19%)]. T2* MRI revealed increased liver iron but no cardiac iron (13/13). Anemia improved in the majority of patients who underwent splenectomy (5/6). Three patients died (9%) at the age of 46-56 due to PAH (1) and sepsis (2). All previously underwent splenectomy. Analyzing both our patients and the 21 patients previously described by Heimpel et al. (Blood 107:334, 2006), we conclude that adults with CDA I suffer significant morbidity and mortality. Careful monitoring of iron overload and prompt iron chelation therapy is mandatory. Due to possible complications and inconsistent response to splenectomy α-interferon, transfusion therapy or stem cell transplantation should be considered as alternatives to this procedure in severely affected patients.