A case series highlighting structured hematological, biochemical and molecular approach to clinical oral iron refractoriness in children: A pressing need for a 3-tier system for classification of variants in TMPRSS6 gene.

In current study, we discuss clinical oral iron refractoriness cases and highlight need for a classification system to define TMPRSS6 gene variants. Out of 231 cases of microcytic hypochromic anemia screened (Sept 2019-Dec 2020), 17 cases (7.35%) with unexplained iron refractoriness (URIDA) phenotype were enrolled after ruling out secondary causes and compliance related issues. 11 (65%) had absent/negligible response (0-0.4 g/dl Hb rise) while 6 (35%) partial (0.5-0.9 g/dl Hb rise) response to initial iron trial at 4-8 weeks. Of these 17 cases, inappropriate hepcidin levels (normal-high) were noted in 11/15 (73%) tested. TSAT/Hepcidin ratio was low in 13/15 (87%). Genetic analysis of TMPRSS6 gene by NGS revealed variations in 15/17 (88%) cases. 10/15 cases with variations harbored a common splice site INDEL that was noted to be pathogenic SNP (MAF-0.19) on case-control association study in combination with other known missense SNPs with an odds ratio of 6.38 and relative risk 2.66 (p- < 0.01).

Dizygotic twins with prolonged jaundice and microcytic, hypochromic, hemolytic anemia with pyropoikilocytosis.

Dizygotic twin males, born at 34 weeks gestation, had prolonged jaundice, microcytic, hypochromic anemia, FABarts hemoglobin, elevated end-tidal CO, and blood films consistent with hereditary pyropoikilocytosis. DNA sequencing revealed both had a heterozygous alpha spectrin (SPTA1) mutation (c.460_462dup) inherited from their asymptomatic mother, plus a 3-base pair duplication in alpha globin (HBA2) (c.364_366dupGTG) inherited from their asymptomatic father.

Application of HbA2 levels and red cell indices-based new model in the differentiation of thalassemia traits from iron deficiency in hypochromic microcytic anemia Cases.

INTRODUCTION: Thalassemia traits and iron deficiency anemia are the most common types of hypochromic microcytic anemia with similar clinical and laboratory features. It is vital to establish a new screening model based on HbA2 levels and red cell indices for the differentiation of TT from IDA in hypochromic microcytic anemia cases. METHOD: The data comprised of the red blood cell indices and HbA2 prenatal diagnostic test results of 810 individuals who were identified to conform to the following criteria: MCV < 80 fl or MCH < 26 pg. We launched a new model consisting mainly of significative red cell indices and HbA2 levels, as well as proposing cutoff values by using decision trees and logistic regression analyses. Next, we evaluated our new method by comparing the sensitivity, specificity, positive, and negative predictive values with those of the previous formulas. RESULTS: We put forward a new model and compared it with 5 efficient formulas. The new model exhibited the highest accuracy (0.918), with its sensitivity and specificity calculated as 0.917 and 0.921, respectively. Our new model's Youden index was 0.838, which is higher than the other formulas' Youden indices. CONCLUSIONS: The new screening model, based on HbA2 levels and red cell indices, is suitable for the screening of thalassemia patients in the hypochromic microcytic anemia group and has the best efficiency in distinguishing TT and IDA.

Reticulocyte hemoglobin and hypochromic erythrocytes in the study of erythropoiesis in patients with inflammatory bowel disease.

Anemia due to lack of iron (absolute or functional deficiency) is a common complication of inflammatory bowel disease (IBD). We investigated the potential utility of reticulocyte hemoglobin content (Ret-He) and percentage of hypochromic red cells (Hypo-He) in the assessment of erythropoiesis. We recruited 123 anemic outpatients with IBD. Biochemical tests for iron deficiency were carried out. Full blood counts were performed on a XN 20 system (Sysmex Diagnostics). Differences among groups were studied using analysis of variance and post-hoc tests, considering p < .05 to be significant. Receiver operating characteristic analysis was used to assess the diagnostic performance of Ret-He and Hypo-He for detecting iron-deficient erythropoiesis. The gold standard used for diagnosing iron deficiency was soluble transferrin receptor (sTfR), with a cut-off of >52 nmol/L. Overall, 60 patients had iron deficiency anemia (IDA), 27 anemia of chronic disease (ACD) and 36 mixed ACD + IDA. Ret-He showed the best performance, with an area under curve (AUC) of 0.858 (95% CI 0.816-0.952), considering a cut-off of 30.0 pg, sensitivity of 76.8% and specificity of 99.8% (vs. AUC 0.727 [95% CI 0.624-0.814], considering a cut-off of 4.0%, sensitivity 72.0% and specificity 72.5% for Hypo-He). Ret-He and Hypo-He can be used to assess iron supply for erythropoiesis in patients with IBD, to evaluate long-term (Hypo-He) and short-term (Ret-He) periods.

Relative hypochromia and mortality in acute heart failure.

BACKGROUND: Relative hypochromia of erythrocytes defined as a reduced mean corpuscular hemoglobin concentration (MCHC) is a surrogate of iron deficiency. We aimed to evaluate the prevalence and prognostic impact of relative hypochromia in acute heart failure (AHF). METHODS: We prospectively characterized 1574 patients presenting with an adjudicated diagnosis of AHF to the emergency department. Relative hypochromia was defined as a MCHC ≤330 g/l and determined at presentation. The presence of AHF was adjudicated by two independent cardiologists. All-cause mortality and AHF-rehospitalization were the primary prognostic end-points. RESULTS: Overall, 455 (29%) AHF patients had relative hypochromia. Patients with relative hypochromia had higher hemodynamic cardiac stress as quantified by NT-proBNP concentrations (p < 0.001), more extensive cardiomyocyte injury as quantified by high-sensitive cardiac troponin T (hs-cTnT) concentrations (p < 0.001), and lower estimated glomerular filtration rate (eGFR; p < 0.001) as compared to AHF patients without hypochromia. Cumulative incidences for all-cause mortality and AHF-rehospitalization at 720-days were 50% and 55% in patients with relative hypochromia as compared to 33% and 39% in patients without hypochromia, respectively (both p < 0.0001). The association between relative hypochromia and increased mortality (HR 1.7, 95% CI 1.4-2-0) persisted after adjusting for anemia (HR 1.5, 95% CI 1.3-1.8), and after adjusting for hemodynamic cardiac stress (HR 1.46, 95% CI 1.21-1.76) and eGFR (HR 1.5, 95% CI 1.3-1.8, p < 0.001). CONCLUSIONS: Relative hypochromia is common and a strong and independent predictor of increased mortality in AHF. Given the direct link to diagnostic (endoscopy) and therapeutic interventions to treat functional iron deficiency, relative hypochromia deserves increased attention as an inexpensive and universally available biomarker.

Neuronopathic Gaucher disease presenting with microcytic hypochromic anemia.

Gaucher disease (GD) is caused by a hereditary deficiency of glucocerebrosidase, resulting in accumulation of glucosylceramide and potentially manifesting as hepatosplenomegaly. We report the case of a 15-month-old boy with chronic neuronopathic GD. The patient had prolonged anemia despite continued iron supplementation for 3 months. White blood count (WBC), hemoglobin (Hb), platelet count, and corrected reticulocyte count were 3,300 /µL, 8.7 g/dL, 90,000 /µL, and 0.55, respectively. The patient had microcytic hypochromic anemia with mildly elevated ferritin. Physical examination revealed hepatosplenomegaly. Bone-marrow aspiration showed sheets of Gaucher cells. Glucocerebrosidase activity in monocytes was significantly lower than normal. Genetic analysis revealed a homozygous L444P mutation of GBA, and he was diagnosed with type 1 GD. Enzyme replacement treatment (ERT) consisting of imiglucerase was initiated and was effective; WBC, Hb, and platelet count gradually normalized and the hepatosplenomegaly improved. However, when the patient entered elementary school, he showed mild impaired cognitive function, and supranuclear gaze palsy occurred the same year. He was ultimately diagnosed with type 3 GD and continued ERT. Pediatric hemato-oncologists should be aware of GD, especially when patients exhibit anemia refractory to iron therapy, radiologic bone deformity, neurologic signs or symptoms, and growth retardation.

Identificación de &-talasemia en anemias microcíticas hipocrómicas refractarias al tratamiento con hierro en Nicaragua / Identification of &-thalassemia in hypochromic microcytic anemias refractory to iron treatment in Nicaragua

Resumen Justificación y objetivo: gran parte de los casos descritos de anemias microcíticas-hipocrómicas corresponden a anemias ferropénicas y síndromes talasémicos. El diagnóstico diferencial se complementa con pruebas de laboratorio como el hierro sérico, ferritina, entre otras; sin embargo, estas son de baja disponibilidad en países en vías de desarrollo. En Nicaragua, el diagnóstico de estas patologías se basa en el historial clínico y análisis hematológicos de rutina. El objetivo de este trabajo fue la implementación de la técnica de cuantificación de hemoglobina A2 en el diagnóstico clínico de β-talasemia. Métodos: se realizó un estudio transversal con 30 pacientes que mostraban microcitosis e hipocromía después de 3 meses de tratamiento con sales de hierro. Se realizó electroforesis de hemoglobina y se utilizó el kit de la casa comercial Beta-Thal HbA2 Quik Column para cuantificar la hemoglobina A2 en cada paciente. El análisis estadístico utilizado fue la prueba de t de student. Se consideraron significativas las diferencias a p<0,05. Esta investigación respetó los principios éticos que conciernen. Se contó con la aprobación del Comité de Ética Institucional, UNAN-Managua. Los participantes dieron su consentimiento informado. Resultados: al aplicar el método para cuantificación de hemoglobina A2, se obtuvo que el 67 % de las muestras presentaron una concentración de hemoglobina A2 mayor al valor de referencia establecido (3,3 %), siendo pacientes diagnosticados para β-talasemia menor. El 33 % restante presentó valores normales de hemoglobina A2 con microcitosis e hipocromía. Se encontraron diferencias estadísticamente significativas entre las medias de glóbulos rojos, volumen corpuscular medio, hemoglobina corpuscular media y hemoglobina A2, entre ambos grupos. Conclusión: el diagnóstico diferencial de anemias microcíticas hipocrómicas refractarias al tratamiento con hierro, se realiza inicialmente por el historial clínico del paciente, pero es necesario contar con pruebas diagnósticas como la cuantificación de hemoglobina A2 que permitan identificar las diversas patologías que cursan con microcitosis e hipocromía.

Abstract Justification and objective: much of the described cases of microcytic-hypochromic anemias are ferropenic anemias and Thalassemia syndromes. The differential diagnosis is complemented by laboratory tests as serum iron, ferritin, among others; However, these are of low availability in developing countries. In Nicaragua, the diagnosis of these diseases is based on clinical history and routine blood analysis. The objective of this work was to implement a technique for quantification of hemoglobin A2 in the clinical diagnosis of β-Thalassemia. Methods: We conducted a cross-sectional study with 30 patients showing hypochromia and microcytosis after 3 months of treatment with iron salts. Hemoglobin electrophoresis was performed, a kit from Beta-Thal HbA2 Quik Column was used to quantify the hemoglobin A2 in each patient. The statistical analysis used was the student's t test. The differences were considered significant at p < 0.05. This research respected ethical principles that concern. It had the approval of the committee of ethics institutional, UNAN-Managua and the participants gave their informed consent. Results: when applying the method for quantification of hemoglobin A2, 67% of samples presented a concentration of hemoglobin A2 greater than the reference value set at 3.3%, these patients were diagnosed with β-Thalassemia minor. The remaining 33% presented normal values of hemoglobin A2 with hypochromia and microcytosis. Statistically significant differences between the averages of red blood cells, mean corpuscular volume, mean corpuscular hemoglobin and hemoglobin A2 between the two groups was observed. Conclusion: The differential diagnosis of microcytic hypochromic anemias refractory to treatment with iron, is initially performed by the clinical history of the patient, but it is necessary to have diagnostic tests such as the quantification of hemoglobin A2, which allow the identification of patients with β-Thalassemia minor within this group. In our study 67% of the studied samples were identified as β-Thalassemia minor.

Novel interactions of two α-Hb variants with SEA deletion α0-thalassemia: hematological and molecular analyses.

OBJECTIVES: To report the hematological and molecular features as well as diagnostic aspects of the hitherto un-described interactions of two rare α-globin chain variants with α0-thalassemia commonly found among Southeast Asian populations. METHODS: The study was done on two adult Thai patients (P1 and P2) who had hypochromic microcytic anemia. Hb analysis was carried out using high performance liquid chromatography (HPLC) and capillary electrophoresis (CE). Mutations were identified by PCR and related techniques. RESULTS: Hb analysis of P1 using HPLC showed a normal Hb pattern, but CE demonstrated an abnormal peak at zone 7. DNA sequencing identified a CCG-CTG mutation at codon 95 of the α2 globin gene corresponding to the Hb G-Georgia [α95(G2)Pro → Leu(α2)] previously undescribed in the Thai population. In contrast, Hb analysis of P2 demonstrated an abnormal peak not fully separated from Hb A on HPLC, but not on CE. DNA analysis identified the rarely described Hb Nakhon Ratchasima [α63(E12)Ala → Val(α2)] mutation. Routine DNA analysis detected the SEA deletion α0-thalassemia in trans to the Hb variants in both cases. Hematological parameters were compared with those of patients with compound heterozygote for other α-globin variants and α0-thalassemia previously documented. CONCLUSIONS: Identification of the patients confirmed that interaction of these rare Hb variants with α0-thalassemia does not lead to the Hb H disease. Differentiation of these two Hb variants from other clinically relevant hemoglobinopathies in a routine setting is, however, necessary. This can be accomplished using a combined Hb-HPLC and CE analysis followed by PCR-RFLP assays.

A mouse model of hereditary coproporphyria identified in an ENU mutagenesis screen.

A genome-wide ethyl-N-nitrosourea (ENU) mutagenesis screen in mice was performed to identify novel regulators of erythropoiesis. Here, we describe a mouse line, RBC16, which harbours a dominantly inherited mutation in the Cpox gene, responsible for production of the haem biosynthesis enzyme, coproporphyrinogen III oxidase (CPOX). A premature stop codon in place of a tryptophan at amino acid 373 results in reduced mRNA expression and diminished protein levels, yielding a microcytic red blood cell phenotype in heterozygous mice. Urinary and faecal porphyrins in female RBC16 heterozygotes were significantly elevated compared with that of wild-type littermates, particularly coproporphyrinogen III, whereas males were biochemically normal. Attempts to induce acute porphyric crises were made using fasting and phenobarbital treatment on females. While fasting had no biochemical effect on RBC16 mice, phenobarbital caused significant elevation of faecal coproporphyrinogen III in heterozygous mice. This is the first known investigation of a mutagenesis mouse model with genetic and biochemical parallels to hereditary coproporphyria.

Loss of Dynamin 2 GTPase function results in microcytic anaemia.

In a dominant mouse ethylnitrosurea mutagenesis screen for genes regulating erythropoiesis, we identified a pedigree with a novel microcytic hypochromia caused by a V235G missense mutation in Dynamin 2 (Dnm2). Mutations in Dnm2, a GTPase, are highly disease-specific and have been implicated in four forms of human diseases: centronuclear myopathy, Charcot-Marie Tooth neuropathy and, more recently, T-cell leukaemia and Hereditary Spastic Paraplegia, but red cell abnormalities have not been reported to date. The V235G mutation lies within a crucial GTP nucleotide-binding pocket of Dnm2, and resulted in defective GTPase activity and incompatibility with life in the homozygous state. Dnm2 is an essential mediator of clathrin-mediated endocytosis, which is required for the uptake of transferrin (Tf) into red cells for incorporation of haem. Accordingly, we observed significantly reduced Tf uptake by Dnm2+/V235G cells, which led to impaired endosome formation. Despite these deficiencies, surprisingly all iron studies were unchanged, suggesting an unexplained alternative mechanism underlies microcytic anaemia in Dnm2+/V235G mice. This study provides the first in vivo evidence for the requirements of Dnm2 in normal erythropoiesis.

Effects of GlyT1 inhibition on erythropoiesis and iron homeostasis in rats.

Glycine is a key rate-limiting component of heme biosynthesis in erythropoietic cells, where the high intracellular glycine demand is primarily supplied by the glycine transporter 1 (GlyT1). The impact of intracellular glycine restriction after GlyT1 inhibition on hematopoiesis and iron regulation is not well established. We investigated the effects of a potent and selective inhibitor of GlyT1, bitopertin, on erythropoiesis and iron homeostasis in rats. GlyT1 inhibition significantly affected erythroid heme biosynthesis, manifesting as microcytic hypochromic regenerative anemia with a 20% steady-state reduction in hemoglobin. Reduced erythropoietic iron utilization was characterized by down-regulation of the transferrin receptor 1 (TfR1) on reticulocytes and modest increased iron storage in the spleen. Hepatic hepcidin expression was not affected. However, under the condition of reduced heme biosynthesis with reduced iron reutilization and increased storage iron, hepcidin at the lower and higher range of normal showed a striking role in tissue distribution of iron. Rapid formation of iron-positive inclusion bodies (IBs) was observed in circulating reticulocytes, with an ultrastructure of iron-containing polymorphic mitochondrial remnants. IB or mitochondrial iron accumulation was absent in bone marrow erythroblasts. In conclusion, GlyT1 inhibition in rats induced a steady-state microcytic hypochromic regenerative anemia and a species-specific accumulation of uncommitted mitochondrial iron in reticulocytes. Importantly, this glycine-restricted anemia provides no feedback signal for increased systemic iron acquisition and the effects reported are pathogenetically distinct from systemic iron-overload anemias and erythropoietic disorders such as acquired sideroblastic anemia.

Determination of functional iron deficiency status in haemodialysis patients in central South Africa.

INTRODUCTION: Functional iron deficiency (FID) is characterized by adequate body iron stores with an inadequate rate of iron delivery for erythropoiesis. In chronic kidney failure (CKD), iron availability is best assessed using the percentage of hypochromic red cells (%Hypo). The aim of our study was to determine the FID status of haemodialysis patients in central South Africa, using the %Hypo analyte and to evaluate the ability of the currently used biochemical tests, transferrin saturation (TSat) and serum ferritin to diagnose FID. METHODS: For this study, 49 patients on haemodialysis were recruited. Haemoglobin (Hb), mean cell volume (MCV) and %Hypo were measured on the Advia 2120i. Biochemical analytes (serum ferritin, TSat) and C-reactive protein (CRP) levels were also recorded. RESULTS: Of the 49 participants, 21 (42.9%) were diagnosed with FID (%Hypo >6%). A large number of patients (91.8%) were anaemic. The TSat demonstrated poor sensitivity and specificity for diagnosing FID compared with %Hypo. The use of %Hypo (rather than TSat) to guide intravenous iron use spared 16 patients the potential harmful effects thereof. CONCLUSION: Using %Hypo as a single analyte to diagnose FID will lead to more appropriate use of limited resources and a reduction in treatment-related complications.

Clinical Value of Hypochromia Markers in the Detection of Latent Iron Deficiency in Nonanemic Premenopausal Women.

BACKGROUND: Iron deficiency (ID) is the most common cause of anemia in fertile women and hemoglobin (Hb) within the reference interval does not exclude ID. The consequence of an imbalance between the iron requirements and supply is a reduction of red-cell Hb content, which causes hypochromic cells. The aim of this study was to assess the reliability of new parameters low Hb density (LHD%), reticulocyte Hb equivalent (RetHe), and percentage of hypochromic erythrocytes (%HypoHe) in the detection of latent ID (LID), defined as depletion of iron stores without anemia. METHODS: Two hundred fifty consecutive nonanemic women in fertile age (18-40 years, mean 33.5 years), whose analyses had been requested by general practitioners, were included. Independent samples t-test, receiver operating characteristic (ROC) curve analysis (gold standard for detecting LID ferritin <30 µg/l), and Cohen's kappa index were applied. RESULTS: One hundred fifty-three women had ferritin within the reference range and Hb >120 g/L; 97 (38.8%) had LID. The results were as follows: %HypoHe-AUC 0.934, cutoff 1.6%, sensitivity 85.7%, specificity 92.1%; RetHe-AUC 0.914, cutoff 29.9 pg, sensitivity 86.8%, specificity 85.7%; LHD%-AUC 0.898, cutoff 5.0%, sensitivity 85.9%, specificity 84.1%. Applying those cutoffs, agreement between ferritin and %HypoHe was κ 0.61 and 0.56 for RetHe and LHD%. CONCLUSIONS: LHD%, %HypoHe, and RetHe emerge as reliable tests for the investigation of LID and could improve the ability to detect ID before anemia is present.

Usefulness of Relative Hypochromia in Risk Stratification for Nonanemic Patients With Chronic Heart Failure.

The purpose of this study is to investigate the impact of a reduction of hemoglobin (Hb) content in the erythrocytes as estimated by mean corpuscular hemoglobin concentration (MCHC) on long-term clinical outcomes in nonanemic patients with heart failure (HF). We prospectively enrolled 1,579 subjects with HF who underwent coronary angiography enrolled in the GeneBank study with 5-year follow-up of all-cause mortality. Levels of Hb and MCHC were assessed at enrollment and after 6 months of follow-up. Anemia was defined as Hb levels <13 g/dl in men and <12 g/dl in women. In our nonanemic cohort (n = 785, 49.7%), mean Hb and median MCHC were 13.8 ± 1.1 g/dl and 34.3 g/dL (interquartile range 33.6 to 35), respectively. Nonanemic patients with heart failure with lower MCHC had higher mortality risk (quartiles 1 vs 4, hazard ratio = 2.1, 95% confidence interval 1.4 to 3.3, p = 0.001). In a subset of nonanemic patients with persistent normal Hb on follow-up (n = 206), the mean time between baseline and follow-up MCHC levels was 169.3 ± 41.6 days. In comparison with patients with levels of MCHC more than the first quartile (≥33.6 g/dl) on baseline and follow-up, patients with persistently low MCHC (<33.6 g/dl) had a significantly increased mortality risk (log rank <0.001). All models remained significant even after adjusting for traditional cardiac risk factors, left ventricular ejection fraction, baseline Hb levels, and mean corpuscular volume. In conclusion, relative hypochromia is an independent predictor of increased mortality risk in patients with HF, even in the setting of normal Hb levels.

A Rare Haemoglobin Variant Identified as K Woolwich in a Pakistani Male.

Haemoglobin (Hb) K Woolwich is a rare Hb variant which was first described in a family from West Indies and its occurrence was later reported mainly in Black families from many African countries. We report a case of a young male who came for evaluation of anemia. His complete blood count showed hypochromic, microcytic anemia and his serum ferritin was low. Hb electrophoresis done as part of initial workup showed an abnormal band which moved faster than HbA. For further evaluation, Hb analysis by high performance liquid chromatography was subsequently performed and revealed Hb K Woolwich. This is a rare Hb variant recognized in Pakistani population for the first time through careful interpretation of the chromatographic behavior of the Hb.

Diagnosis of iron-deficient states.

The diagnosis of iron deficiency anemia is typically straightforward, especially when classic biochemical and hematological changes are present in a subject at risk. It can be challenging in the presence of diseases or when it is due to inherited defects of iron metabolism. The identification of iron deficiency prior to anemia development is also difficult. New hematological parameters such as reticulocyte Hb content have expanded the classic ones such as MCV, MCH and MCHC. A variety of hematology analyzers now provide novel parameters to assess cellular hypochromia and microcytosis in both reticulocytes and mature red blood cells. The repertoire of biochemical markers has also been expanded, with iron, transferrin and ferritin being supplemented by circulating transferrin receptor and hepcidin. Molecular identification of functional variants of key iron metabolism determinants has provided explanations for the heritability of some iron metabolism biomarkers. Genetic defects in some of these molecules are responsible for hereditary microcytic anemias, also called atypical microcytic anemias. In this review, we examine the most significant hematological and biochemical markers for iron metabolism, as well as relevant genetic polymorphisms and defects affecting iron handling.