Improved method for assessing iron stores in the bone marrow

Bone marrow iron scoring in healthy and clinically ill dogs with and without evidence of iron-restricted erythropoiesis

BACKGROUND

There are few reports in dogs that have evaluated the utility of semi-quantitative scoring of bone marrow iron stores in conjunction with reticulocyte hemoglobin (CHr) to identify iron-restricted erythropoiesis due to absolute iron deficiency or iron sequestration.

OBJECTIVES

An established system for scoring iron stores in human bone marrow samples was applied to dogs. The objectives were to evaluate interobserver agreement (Κ_ω ), determine marrow iron scores in dogs without detectable hematologic abnormalities, and assess combined interpretation of iron scores and CHr to evaluate for iron-restricted erythropoiesis.

METHODS

Four blinded observers independently scored iron in 139 Prussian blue-stained canine marrow samples from 0 (none) to 6 (very heavy), including healthy controls (n = 12), clinically ill dogs with (n = 100) and without (n = 16) detectable hematologic abnormalities, and dogs with experimental nutritional iron deficiency (n = 11). Additional medical record data were available for 118 dogs to evaluate for other evidence of iron deficiency (abnormal CHr, RBC indices, serum iron variables, external blood loss, or nutritional deficiencies).

RESULTS

Mean Κ_ω was 0.69 (substantial agreement) for all samples but was 0.44 (moderate agreement) for samples with iron scores <3, indicating distinguishing scores 0-2 may not be reliable. Dogs without detectable hematologic abnormalities had scores from 3-5. Dogs with scores <3 and decreased CHr often had more indicators of iron deficiency vs dogs only having low iron scores or low CHr.

CONCLUSIONS

Evaluation of dogs with marrow iron score <3 for external blood loss or nutritional deficiencies is likely clinically worthwhile, particularly if there is also decreased CHr.

Iron deficiency in sepsis patients managed with divided doses of iron dextran: a prospective cohort study

Iron deficiency (ID) impairs hemoglobin (Hb) synthesis and immune function, both crucial for sepsis patients. We assessed the impact of iron dextran on reticulocyte (Ret) Hb equivalent (Ret-He) and Ret subpopulations in iron-deficient sepsis patients. In this prospective clinical study we enrolled patients with sepsis or septic shock with procalcitonin concentration > 0.5 ng/mL, diagnosed with ID based on Ret-He. Study subjects received divided doses of iron dextran until normalization of Ret-He. The study population included 35 subjects. The median Ret-He increase after 2 doses of iron dextran was 3.0 (IQR 1.9-6.1) pg (p < 0.01) with median time to normalization 4 (IQR 3-5) days. Although no change in Ret percentage [Me 1.5 (IQR 1.1-2.1) vs. Me 1.4 (IQR 1.1-2.4) %, p = 0.39] and number [Me 0.05 (IQR 0.04-0.07) vs. Me 0.05 (IQR 0.03-0.06) 10⁶/µL, p = 0.88] was noted, Ret subpopulations changed significantly (p for all < 0.01). Divided doses of iron dextran relatively quickly normalize Ret-He in iron-deficient sepsis patients. Changes in Ret subpopulations suggest increased erythropoietic activity. Further research is needed to explore the role of intravenous iron in this clinical setting.

The Association between Iron Deficiency and Renal Outcomes Is Modified by Sex and Anemia in Patients with Chronic Kidney Disease Stage 1–4

Iron deficiency is prevalent in women and patients with chronic kidney disease (CKD). Iron deficiency is not only related to anemia but contributes to adverse consequences for the kidney as well. Whether iron status is associated with renal outcomes after considering sex and anemia in patients with CKD stage 1–4 is unclear. Thus, we investigated the association of iron or iron saturation with renal outcomes in a CKD cohort. During a follow-up of 8.2 years, 781 (31.2%) patients met the composite renal outcome of renal replacement therapy and a 50% decline in renal function. In linear regression, iron was associated with sex, hemoglobin (Hb), and nutritional markers. In a fully adjusted Cox regression model, the male patients with normal iron had a significantly decreased risk of renal outcomes (hazard ratio (HR) 0.718; 95% confidence interval (CI) 0.579 to 0.889), but the female patients did not exhibit this association. The non-anemic patients (Hb ≥ 11 g/dL) had a decreased risk of renal outcomes (HR 0.715; 95% CI 0.568 to 0.898), but the anemic patients did not. In the sensitivity analysis, transferrin saturation (TSAT) showed similar results. When comparing iron and TSAT, both indicators showed similar prognostic values. In conclusion, iron deficiency, indicated by either iron or iron saturation, was associated with poor renal outcomes in the male or non-anemic patients with CKD stage 1–4.

Underdiagnosis of iron deficiency anaemia in HIV-infected individuals: a pilot study using soluble transferrin receptors and intensive bone marrow iron stores to improve the diagnosis

AIM

We compared soluble transferrin receptors (sTfR), serum ferritin, mean cell volume (MCV) of red cells and the sTfR-ferritin index with the intensive method bone marrow trephine (BMT) iron stores in the diagnosis of iron deficiency anaemia (IDA) in Human Immunodeficiency Virus (HIV)-positive hospitalised participants.

METHODS

In this cross-sectional study, we recruited hospitalised HIV-positive and coronavirus of 2019 (COVID-19)-negative adults with anaemia who required a bone marrow examination as part of their diagnostic workup. We measured the full blood count, ferritin, sTfR and assessed iron using the intensive method in Haemotoxylin and Eosin (H&E)-stained BMT core biopsies of consenting participants.

RESULTS

Of the 60 enrolled participants, 57 were evaluable. Thirteen (22.80%) had IDA on H&E BMT iron stores assessment, and 44 (77.19%) had anaemia of chronic diseases (ACD). The sTfR and the sTfR-ferritin index had sensitivities of 61.54% and 53.85%, respectively, for IDA diagnosis. The sensitivity and specificity of ferritin was 7.69% and 92.31%, respectively. The sTfR and sTfR-ferritin index's diagnostic specificity was relatively low at 46.15% and 38.46%, respectively.

CONCLUSION

In this pilot study in HIV-positive participants, the prevalence of iron deficiency using the BMT assessment was low. Both the sTfR and the sTfR-ferritin index had a better quantitative correlation to bone marrow iron stores when compared with the MCV and ferritin and, may be more accurate surrogate markers of IDA.

Severe microcytosis in a hemoglobin E/Β-thalassemia patient with signs of iron deficiency: A case report

Background

β-thalassemia is a hereditary disorder characterized by a decrease in the synthesis of β-globin chains that decreases hemoglobin in erythrocytes, low erythrocyte production, and anemia.

Case presentation

A 6-year-old girl came with complaints of paleness for one week. Physical examination showed vital signs within normal limits, conjunctival anemia, and hepatomegaly. Investigations: HGB 5.4 g/dL, MCV 44.5 fL, MCH 15.5 pg, MCHC 34.8 g/dL, RDW-CV 29.2%, WBC 4,770/μL, PLT 2,728,000/μL, Serum iron 29 g/dL, TIBC 217 g/dL and transferrin saturation of 13.36%. Peripheral blood smears showed target cells, teardrop cells, ovalocytes, fragmentocytes, cigar cells, and pseudothrombocytosis by automated hematology tools caused by the misinterpretation of small erythrocytes as platelets. Hemoglobin electrophoresis showed a decrease in HbA (4.9%), as well as an increase in HbF (18.3%), HbE (70.5%), and HbA2 (6.3%). The patient was diagnosed with β-thalassemia.

Discussion

Thalassemia with severe microcytosis suggests possible coexistence with iron deficiency. A complete iron profile examination is required in these patients to ensure appropriate and comprehensive medical management.

Conclusion

Iron profile examination plays an essential role in the management and diagnosis of β-thalassemia patients.

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The iron profile investigation should be considered in patients with β-thalassemia.

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Diagnosis of β-thalassemia with microcytosis can be given a blood transfusion.

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PCR transfusion can be considered in managing anaemia in children with β-thalassemia.

Iron supplementation ameliorates aloin-induced iron deficiency anemia in rats

Aloin, an anthraquinone glycoside, is one of other C-glycosides found in the leaf exudate of Aloe plant. Aloin possesses several biologic activities, including antitumor activity in vitro and in vivo. However, aloin treatment has shown iron deficiency anemia and erythropoiesis in vivo. The present study was undertaken to verify if iron supplementation could alleviate these perturbations, compared to doxorubicin, an anthracycline analog. Oral iron supplementation (20.56 mg elemental Fe/kg bw) to aloin-treated rats normalized red blood corpuscles count, hemoglobin concentration, and serum levels of total iron binding capacity and saturated transferrin, as well as hepatic iron content, hepcidin level, and mRNA expression of ferritin heavy chain (Ferr-H) and transferrin receptor-1 (TfR-1) genes. Although, serum hyperferremia, and leukocytosis were maintained, yet the spleen iron overload was substantially modulated. However, combined aloin and iron treatment increased iron storage levels in the heart and bone marrow, compared to aloin treatment per se. On other hand, oral iron supplementation to rats treated with doxorubicin (15 mg/kg bw) lessened the increase in the spleen iron content concomitantly with hepatic hepcidin level, rebound hepatic iron content to normal level, and by contrast augmented serum levels of iron and transferrin saturation. Also, activated Ferr-H mRNA expression and repressed TfR-1 mRNA expression were recorded, compared to doxorubicin treatment per se. Histopathological examination of the major body iron stores in rats supplemented with iron along with aloin or doxorubicin showed an increase in extramedullary hematopoiesis. In conclusion, iron supplementation restores the disturbances in iron homeostasis and erythropoiesis induced by aloin treatment.

Bone Marrow Findings in Renal Patients: A Single Renal Specialist Center Experience

Objective

This study evaluated the importance of bone marrow aspiration and trephine biopsy (BM) for the diagnosis of underlying hematological abnormalities in renal patients.

Methods

This cross-sectional study on BM was carried out between August 2010 and April 2019, in our specialist renal center for various unexplained hematological abnormalities in patients with renal diseases [chronic kidney disease (CKD), end-stage renal disease (ESRD) requiring maintenance hemodialysis (MHD), patients with normal renal function but other nephrology and urology issues like stone disease and nephrotic syndrome].

Results

Out of 176 reported BM examinations, 48 (27.3%) were done on ESRD patients on MHD (CKD-D), and 69 (39.2%) on CKD patients not on MHD (CKD-nD). Fifty-nine (33.5%) BM were done on patients with normal renal function (n-CKD). The indication for BM was pancytopenia 50 (28.4%), unexplained anemia 39 (22.2%), and unexplained thrombocytopenia 43 (24.4%). In 91 (51.7%) patients BM was normal. In 30 (17%) patients multiple myeloma (MM) was diagnosed on BM, out of which 18 (26.1%), nine (18%), three (5.3%) were CKD-nD, CKD-D, and n-CKD patients, respectively. In 11 (6.3%) patients BM was suggestive of myelodysplasia (MD), out of these 11 patients, five (10%) were CKD-D patients.

Conclusion

BM is an underutilized method of diagnosis of hematological abnormalities in renal patients. Our study revealed the importance of BM examination, especially in patients with CKD.

Recent and Emerging Therapies for Iron Deficiency in Anemia of CKD: A Review

Iron deficiency commonly contributes to the anemia affecting individuals with chronic kidney disease. Diagnostic criteria for iron deficiency in chronic kidney disease are explained. Mechanisms of functional and absolute iron deficiency and general treatment Principles as delineated in the Kidney Disease: Improving Global Outcomes guidelines are reviewed. Repletion of absolute iron deficits has progressed over time with the addition of better tolerated, more effective oral agents including ferric citrate, ferric maltol, and sucrosomial iron. Structural characteristics and trial data enabling regulatory approval of these novel oral agents are examined. Newer intravenous iron therapies including ferric carboxymaltose and ferric derisomaltose allow for fewer infusions and decreased risk of serious hypersensitivity reactions. Concerns about adverse events including cardiovascular events and infections are discussed. The potential risk of 6H syndrome due to these intravenous agents, including hypophosphatemia, osteomalacia, and pathologic fractures is emphasized. The proposed pathophysiology of 6H syndrome and hypophosphatemia is described. Ferric pyrophosphate citrate enables administration of iron for repletion through dialysate. Relative merits, costs, and risks of various iron agents such as hypersensitivity and 6H syndrome/hypophosphatemia are summarized.

Comparison of iron staining and scoring methods on canine bone marrow aspirates

BACKGROUND

Insufficient iron for erythropoiesis can occur in multiple conditions, including absolute iron deficiency, which is often caused by chronic external hemorrhage in dogs. Distinguishing this from other causes of iron-restricted erythropoiesis allows appropriate intervention. Decreased marrow iron assessed by Prussian blue staining is a method to diagnose absolute iron deficiency, but scoring systems for marrow iron are not validated in dogs.

OBJECTIVES

Our objectives were to (a) evaluate the technical performance of two bone marrow iron scoring systems used in human medicine and (b) examine the effects of destaining and restaining on iron stores after Wright-stained marrow slides are destained and restained with a Prussian blue stain.

METHODS

Two marrow aspirate slides were included from each of 12 ill dogs in which marrow was collected during clinical evaluation. One slide was directly stained with Prussian blue. The other was first stained with Wright stain, then destained and restained with Prussian blue. Three blinded observers scored the presence of iron in each of the 24 randomized slides using the Gale (scale 0-6) and sideroblast methods (percentage score). Slides were then re-randomized and rescored.

RESULTS

For the Gale method, interobserver agreement was fair, and intraobserver agreement was substantial to perfect. There was less agreement using the sideroblast method, with a significant observer effect. Iron scores were significantly lower in destained slides compared with those stained directly.

CONCLUSIONS

Interobserver and intraobserver agreements were acceptable for the Gale method, but the sideroblast method should be used cautiously. A destaining procedure before Prussian blue staining could decrease marrow iron scores.

Wheat flour fortification with iron and other micronutrients for reducing anaemia and improving iron status in populations

BACKGROUND

Anaemia is a condition where the number of red blood cells (and consequently their oxygen-carrying capacity) is insufficient to meet the body's physiological needs. Fortification of wheat flour is deemed a useful strategy to reduce anaemia in populations.

OBJECTIVES

To determine the benefits and harms of wheat flour fortification with iron alone or with other vitamins and minerals on anaemia, iron status and health-related outcomes in populations over two years of age.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL, 21 other databases and two trials registers up to 21 July 2020, together with contacting key organisations to identify additional studies.

SELECTION CRITERIA

We included cluster- or individually-randomised controlled trials (RCTs) carried out among the general population from any country, aged two years and above. The interventions were fortification of wheat flour with iron alone or in combination with other micronutrients. We included trials comparing any type of food item prepared from flour fortified with iron of any variety of wheat DATA COLLECTION AND ANALYSIS: Two review authors independently screened the search results and assessed the eligibility of studies for inclusion, extracted data from included studies and assessed risks of bias. We followed Cochrane methods in this review.

MAIN RESULTS

Our search identified 3538 records, after removing duplicates. We included 10 trials, involving 3319 participants, carried out in Bangladesh, Brazil, India, Kuwait, Philippines, South Africa and Sri Lanka. We identified two ongoing studies and one study is awaiting classification. The duration of interventions varied from 3 to 24 months. One study was carried out among adult women and one trial among both children and nonpregnant women. Most of the included trials were assessed as low or unclear risk of bias for key elements of selection, performance or reporting bias. Three trials used 41 mg to 60 mg iron/kg flour, three trials used less than 40 mg iron/kg and three trials used more than 60 mg iron/kg flour. One trial used various iron levels based on type of iron used: 80 mg/kg for electrolytic and reduced iron and 40 mg/kg for ferrous fumarate. All included studies contributed data for the meta-analyses. Iron-fortified wheat flour with or without other micronutrients added versus wheat flour (no added iron) with the same other micronutrients added Iron-fortified wheat flour with or without other micronutrients added versus wheat flour (no added iron) with the same other micronutrients added may reduce by 27% the risk of anaemia in populations (risk ratio (RR) 0.73, 95% confidence interval (CI) 0.55 to 0.97; 5 studies, 2315 participants; low-certainty evidence). It is uncertain whether iron-fortified wheat flour with or without other micronutrients reduces iron deficiency (RR 0.46, 95% CI 0.20 to 1.04; 3 studies, 748 participants; very low-certainty evidence) or increases haemoglobin concentrations (in g/L) (mean difference MD 2.75, 95% CI 0.71 to 4.80; 8 studies, 2831 participants; very low-certainty evidence). No trials reported data on adverse effects in children (including constipation, nausea, vomiting, heartburn or diarrhoea), except for risk of infection or inflammation at the individual level. The intervention probably makes little or no difference to the risk of Infection or inflammation at individual level as measured by C-reactive protein (CRP) (mean difference (MD) 0.04, 95% CI -0.02 to 0.11; 2 studies, 558 participants; moderate-certainty evidence). Iron-fortified wheat flour with other micronutrients added versus unfortified wheat flour (nil micronutrients added) It is unclear whether wheat flour fortified with iron, in combination with other micronutrients decreases anaemia (RR 0.77, 95% CI 0.41 to 1.46; 2 studies, 317 participants; very low-certainty evidence). The intervention probably reduces the risk of iron deficiency (RR 0.73, 95% CI 0.54 to 0.99; 3 studies, 382 participants; moderate-certainty evidence) and it is unclear whether it increases average haemoglobin concentrations (MD 2.53, 95% CI -0.39 to 5.45; 4 studies, 532 participants; very low-certainty evidence). No trials reported data on adverse effects in children. Nine out of 10 trials reported sources of funding, with most having multiple sources. Funding source does not appear to have distorted the results in any of the assessed trials.

AUTHORS' CONCLUSIONS

Fortification of wheat flour with iron (in comparison to unfortified flour, or where both groups received the same other micronutrients) may reduce anaemia in the general population above two years of age, but its effects on other outcomes are uncertain. Iron-fortified wheat flour in combination with other micronutrients, in comparison with unfortified flour, probably reduces iron deficiency, but its effects on other outcomes are uncertain. None of the included trials reported data on adverse side effects except for risk of infection or inflammation at the individual level. The effects of this intervention on other health outcomes are unclear. Future studies at low risk of bias should aim to measure all important outcomes, and to further investigate which variants of fortification, including the role of other micronutrients as well as types of iron fortification, are more effective, and for whom.

Optical Imaging and High-Accuracy Quantification of Intracellular Iron Contents

Precise quantification of intracellular iron contents is important to biomedical applications of magnetic nanoparticles. Current approaches for iron quantification rely on specialized instruments while most only yield iron quantities averaged over plenty of cells. Here, a simple and robust approach, combining digital optical microscopy with the Beer-Lambert's law, that allows for imaging stainable iron distribution in individual cells and the quantification of stainable iron contents with an unprecedented accuracy of femtogram per pixel, is presented. It is further shown that this approach enables studying of the internalization and reduction dynamics of super-paramagnetic iron oxide nanoparticles (SPIONs) by stem cells in single cell level.

Accurate Noninvasive Assessment of Myocardial Iron Load in Advanced Heart Failure Patients

Background

Heart failure patients presenting with iron deficiency can benefit from systemic iron supplementation; however, there is the potential for iron overload to occur, which can seriously damage the heart. Therefore, myocardial iron (M-Iron) content should be precisely balanced, especially in already failing hearts. Unfortunately, the assessment of M-Iron via repeated heart biopsies or magnetic resonance imaging is unrealistic, and alternative serum markers must be found. This study is aimed at assessing M-Iron in patients with advanced heart failure (HF) and its association with a range of serum markers of iron metabolism.

Methods

Left ventricle (LV) myocardial biopsies and serum samples were collected from 33 consecutive HF patients (25 males) with LV dysfunction (LV ejection fraction 22 (11) %; NT-proBNP 5464 (3308) pg/ml) during heart transplantation. Myocardial ferritin (M-FR) and soluble transferrin receptor (M-sTfR1) were assessed by ELISA, and M-Iron was determined by Instrumental Neutron Activation Analysis in LV biopsies. Nonfailing hearts (n = 11) were used as control/reference tissue. Concentrations of serum iron-related proteins (FR and sTfR1) were assessed.

Results

LV M-Iron load was reduced in all HF patients and negatively associated with M-FR (r = -0.37, p = 0.05). Of the serum markers, sTfR1/logFR correlated with (r = -0.42; p = 0.04) and predicted (in a step-wise analysis, R ² = 0.18; p = 0.04) LV M-Iron. LV M-Iron load (μg/g) can be calculated using the following formula: 210.24-22.869 × sTfR1/logFR.

Conclusions

The sTfR1/logFR ratio can be used to predict LV M-Iron levels. Therefore, serum FR and sTfR1 levels could be used to indirectly assess LV M-Iron, thereby increasing the safety of iron repletion therapy in HF patients.

Wheat flour fortification with iron for reducing anaemia and improving iron status in populations

BACKGROUND

Anaemia is a condition where the number of red blood cells (and consequently their oxygen-carrying capacity) is insufficient to meet the body's physiologic needs. Fortification of wheat flour is deemed a useful strategy to reduce anaemia in populations.

OBJECTIVES

To determine the benefits and harms of wheat flour fortification with iron alone or with other vitamins and minerals on anaemia, iron status and health-related outcomes in populations over two years of age.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL, and other databases up to 4 September 2019.

SELECTION CRITERIA

We included cluster- or individually randomised controlled trials (RCT) carried out among the general population from any country aged two years and above. The interventions were fortification of wheat flour with iron alone or in combination with other micronutrients. Trials comparing any type of food item prepared from flour fortified with iron of any variety of wheat were included.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the search results and assessed the eligibility of studies for inclusion, extracted data from included studies and assessed risk of bias. We followed Cochrane methods in this review.

MAIN RESULTS

Our search identified 3048 records, after removing duplicates. We included nine trials, involving 3166 participants, carried out in Bangladesh, Brazil, India, Kuwait, Phillipines, Sri Lanka and South Africa. The duration of interventions varied from 3 to 24 months. One study was carried out among adult women and one trial among both children and nonpregnant women. Most of the included trials were assessed as low or unclear risk of bias for key elements of selection, performance or reporting bias. Three trials used 41 mg to 60 mg iron/kg flour, two trials used less than 40 mg iron/kg and three trials used more than 60 mg iron/kg flour. One trial employed various iron levels based on type of iron used: 80 mg/kg for electrolytic and reduced iron and 40 mg/kg for ferrous fumarate. All included studies contributed data for the meta-analyses. Seven studies compared wheat flour fortified with iron alone versus unfortified wheat flour, three studies compared wheat flour fortified with iron in combination with other micronutrients versus unfortified wheat flour and two studies compared wheat flour fortified with iron in combination with other micronutrients versus fortified wheat flour with the same micronutrients (but not iron). No studies included a 'no intervention' comparison arm. None of the included trials reported any other adverse side effects (including constipation, nausea, vomiting, heartburn or diarrhoea). Wheat flour fortified with iron alone versus unfortified wheat flour (no micronutrients added) Wheat flour fortification with iron alone may have little or no effect on anaemia (risk ratio (RR) 0.81, 95% confidence interval (CI) 0.61 to 1.07; 5 studies; 2200 participants; low-certainty evidence). It probably makes little or no difference on iron deficiency (RR 0.43, 95% CI 0.17 to 1.07; 3 studies; 633 participants; moderate-certainty evidence) and we are uncertain about whether wheat flour fortified with iron increases haemoglobin concentrations by an average 3.30 (g/L) (95% CI 0.86 to 5.74; 7 studies; 2355 participants; very low-certainty evidence). No trials reported data on adverse effects in children, except for risk of infection or inflammation at the individual level. The intervention probably makes little or no difference to risk of Infection or inflammation at individual level as measured by C-reactive protein (CRP) (moderate-certainty evidence). Wheat flour fortified with iron in combination with other micronutrients versus unfortified wheat flour (no micronutrients added) Wheat flour fortified with iron, in combination with other micronutrients, may or may not decrease anaemia (RR 0.95, 95% CI 0.69 to 1.31; 2 studies; 322 participants; low-certainty evidence). It makes little or no difference to average risk of iron deficiency (RR 0.74, 95% CI 0.54 to 1.00; 3 studies; 387 participants; moderate-certainty evidence) and may or may not increase average haemoglobin concentrations (mean difference (MD) 3.29, 95% CI -0.78 to 7.36; 3 studies; 384 participants; low-certainty evidence). No trials reported data on adverse effects in children. Wheat flour fortified with iron in combination with other micronutrients versus fortified wheat flour with same micronutrients (but not iron) Given the very low certainty of the evidence, the review authors are uncertain about the effects of wheat flour fortified with iron in combination with other micronutrients versus fortified wheat flour with same micronutrients (but not iron) in reducing anaemia (RR 0.24, 95% CI 0.08 to 0.71; 1 study; 127 participants; very low-certainty evidence) and in reducing iron deficiency (RR 0.42, 95% CI 0.18 to 0.97; 1 study; 127 participants; very low-certainty evidence). The intervention may make little or no difference to the average haemoglobin concentration (MD 0.81, 95% CI -1.28 to 2.89; 2 studies; 488 participants; low-certainty evidence). No trials reported data on the adverse effects in children. Eight out of nine trials reported source of funding with most having multiple sources. Funding source does not appear to have distorted the results in any of the assessed trials.

AUTHORS' CONCLUSIONS

Eating food items containing wheat flour fortified with iron alone may have little or no effect on anaemia and probably makes little or no difference in iron deficiency. We are uncertain on whether the intervention with wheat flour fortified with iron increases haemoglobin concentrations improve blood haemoglobin concentrations. Consuming food items prepared from wheat flour fortified with iron, in combination with other micronutrients, has little or no effect on anaemia, makes little or no difference to iron deficiency and may or may not improve haemoglobin concentrations. In comparison to fortified flour with micronutrients but no iron, wheat flour fortified with iron with other micronutrients, the effects on anaemia and iron deficiency are uncertain as certainty of the evidence has been assessed as very low. The intervention may make little or no difference to the average haemoglobin concentrations in the population. None of the included trials reported any other adverse side effects. The effects of this intervention on other health outcomes are unclear.

Classic and emergent indicators for the assessment of human iron status

Iron deficiency is the leading cause of anemia, a significant global public health problem. Different methods exist for assessing iron nutritional status, including laboratory tests that focus on storage, transportation, and iron functional compartment parameters. Classical markers such as bone marrow, serum iron, ferritin, hemoglobin, erythrocyte parameters, transferrin, transferrin receptors, and zinc protoporphyrin are discussed in this review. Additional parameters calculated from these indicators, including transferrin saturation, ferritin index and Thomas plot, and some emergent parameters such as hepcidin, erythroferrone, and low hemoglobin density are also discussed. There is no a single indicator for assessing iron nutritional status. Therefore, the use of more than one indicator may be the best practice to obtain the correct diagnosis, also considering the influence of inflammation/infection on many of these indicators. The constant validation of the current parameters, the improvement of assessment methods, and the identification of new indicators will be the key to refine the assessment of iron nutritional status and the right choice of treatment for its improvement.

Iron Deficiency in Chronic Kidney Disease: Updates on Pathophysiology, Diagnosis, and Treatment

Anemia is a complication that affects a majority of individuals with advanced CKD. Although relative deficiency of erythropoietin production is the major driver of anemia in CKD, iron deficiency stands out among the mechanisms contributing to the impaired erythropoiesis in the setting of reduced kidney function. Iron deficiency plays a significant role in anemia in CKD. This may be due to a true paucity of iron stores (absolute iron deficiency) or a relative (functional) deficiency which prevents the use of available iron stores. Several risk factors contribute to absolute and functional iron deficiency in CKD, including blood losses, impaired iron absorption, and chronic inflammation. The traditional biomarkers used for the diagnosis of iron-deficiency anemia (IDA) in patients with CKD have limitations, leading to persistent challenges in the detection and monitoring of IDA in these patients. Here, we review the pathophysiology and available diagnostic tests for IDA in CKD, we discuss the literature that has informed the current practice guidelines for the treatment of IDA in CKD, and we summarize the available oral and intravenous (IV) iron formulations for the treatment of IDA in CKD. Two important issues are addressed, including the potential risks of a more liberal approach to iron supplementation as well as the potential risks and benefits of IV versus oral iron supplementation in patients with CKD.

Estimating the burden of iron deficiency among African children

BACKGROUND

Iron deficiency (ID) is a major public health burden in African children and accurate prevalence estimates are important for effective nutritional interventions. However, ID may be incorrectly estimated in Africa because most measures of iron status are altered by inflammation and infections such as malaria. Through the current study, we have assessed different approaches to the prediction of iron status and estimated the burden of ID in African children.

METHODS

We assayed iron and inflammatory biomarkers in 4853 children aged 0-8 years from Kenya, Uganda, Burkina Faso, South Africa, and The Gambia. We described iron status and its relationship with age, sex, inflammation, and malaria parasitemia. We defined ID using the WHO guideline (ferritin < 12 μg/L or < 30 μg/L in the presence of inflammation in children < 5 years old or < 15 μg/L in children ≥ 5 years old). We compared this with a recently proposed gold standard, which uses regression-correction for ferritin levels based on the relationship between ferritin levels, inflammatory markers, and malaria. We further investigated the utility of other iron biomarkers in predicting ID using the inflammation and malaria regression-corrected estimate as a gold standard.

RESULTS

The prevalence of ID was highest at 1 year of age and in male infants. Inflammation and malaria parasitemia were associated with all iron biomarkers, although transferrin saturation was least affected. Overall prevalence of WHO-defined ID was 34% compared to 52% using the inflammation and malaria regression-corrected estimate. This unidentified burden of ID increased with age and was highest in countries with high prevalence of inflammation and malaria, where up to a quarter of iron-deficient children were misclassified as iron replete. Transferrin saturation < 11% most closely predicted the prevalence of ID according to the regression-correction gold standard.

CONCLUSIONS

The prevalence of ID is underestimated in African children when defined using the WHO guidelines, especially in malaria-endemic populations, and the use of transferrin saturation may provide a more accurate approach. Further research is needed to identify the most accurate measures for determining the prevalence of ID in sub-Saharan Africa.

Severe anaemia complicating HIV in Malawi; Multiple co-existing aetiologies are associated with high mortality

BACKGROUND

Severe anaemia is a major cause of morbidity and mortality in HIV-infected adults living in resource-limited countries. Comprehensive data on the aetiology are lacking but are needed to improve outcomes.

METHODS

HIV-infected adults with severe (haemoglobin ≤70g/l) or very severe anaemia (haemoglobin ≤ 50 g/l) were recruited at Queen Elizabeth Central Hospital, Blantyre, Malawi. Fifteen potential causes and associations with anaemia severity and mortality were explored.

RESULTS

199 patients were enrolled: 42.2% had very severe anaemia and 45.7% were on ART. More than two potential causes for anaemia were present in 94% of the patients including iron deficiency (55.3%), underweight (BMI<20: 49.7%), TB infection (41.2%) and unsuppressed HIV infection (viral load >1000 copies/ml) (73.9%). EBV/CMV co-infection (16.5%) was associated with very severe anaemia (OR 2.8 95% CI 1.1-6.9). Overall mortality was high (53%; 100/199) with a median time to death of 17.5 days (IQR 6-55) days. Death was associated with folate deficiency (HR 2.2; 95% CI 1.2-3.8) and end stage renal disease (HR 3.2; 95% CI 1.6-6.2).

CONCLUSION

Mortality among severely anaemic HIV-infected adults is strikingly high. Clinicians should be aware of the urgent need for a multifactorial approach including starting or optimising HIV treatment, considering TB treatment, nutritional support and optimising renal management.

Prevalence, correlates and outcomes of absolute and functional iron deficiency anemia in nondialysis-dependent chronic kidney disease

Background

Anemia is associated with adverse outcomes in those with chronic kidney disease (CKD). We examined the association of absolute and functional iron deficiency anemia (IDA) with adverse outcomes (cardiovascular hospitalization, dialysis and mortality) in those with nondialysis-dependent CKD.

Methods

Nondialysis-dependent CKD patients followed in the US Veterans Administration with hemoglobin level measured within 90 days of the date of the second estimated glomerular filtration rate &lt;60 mL/min/1.73 m2 were included. Logistic regression, multivariate Cox proportional hazards and Poisson regression models adjusted for demographics and comorbidities were used to assess the prevalence and correlates of absolute [transferrin saturation (TSAT) ≤20%, ferritin &lt;100 ng/mL] and functional (TSA T≤20%, ferritin &gt;100–500 ng/mL) IDA and the associations of absolute and functional IDA with mortality, dialysis and cardiovascular hospitalization.

Results

Of 933 463 patients with CKD, 20.6% had anemia. Among those with anemia, 23.6% of patients had both TSAT and ferritin level measured, of whom 30% had absolute IDA and 19% had functional IDA. Absolute IDA in CKD was not associated with an increased risk of mortality or dialysis but was associated with a higher risk of 1-year {risk ratio [RR] 1.20 [95% confidence interval (CI) 1.12–1.28]} and 2-year cardiovascular hospitalization [RR 1.11 (95% CI 1.05–1.17)]. CKD patients with functional IDA had a higher risk of mortality [hazard ratio (HR) 1.11 (95% CI 1.07–1.14)] along with a higher risk of 1-year [RR 1.21 (95% CI 1.1–1.30)] and 2-year cardiovascular hospitalization [RR 1.13 (95% CI 1.07–1.21)]. Ferritin &gt;500 ng/mL (treated as a separate category) was only associated with an increased risk of mortality [HR 1.38 (95% CI 1.26–1.51)].

Conclusions

In a large population of CKD patients with anemia, absolute and functional IDA were associated with various clinical covariates. Functional IDA was associated with an increased risk of mortality and cardiovascular hospitalization, but absolute IDA was associated only with a higher risk of hospitalization.

Definition of Iron Deficiency Based on the Gold Standard of Bone Marrow Iron Staining in Heart Failure Patients

BACKGROUND

The most commonly used definition of iron deficiency (ID; ferritin <100 ng/mL or ferritin 100-300 ng/mL and transferrin saturation [TSAT] <20%) has not been validated in patients with heart failure (HF). We aimed to define and validate the biomarker-based definition of ID in HF, using bone marrow iron staining as the gold standard. Second, we aimed to assess the prognostic value of the optimized definition.

METHODS AND RESULTS

Bone marrow aspiration with iron staining was performed in 42 patients with HF and a reduced left ventricular ejection fraction (≤45%) undergoing median sternotomy for coronary artery bypass grafting. Patients were mostly male (76%) with mild-to-moderate HF and a mean age of 68±10 years. Bone marrow ID was found in 17 (40%) of the HF patients. The most commonly used definition of ID had a sensitivity of 82% and a specificity of 72%. A definition solely based on TSAT ≤19.8% or serum iron ≤13 µmol/L had a sensitivity of 94% and specificity of 84% and 88%, respectively (P<0.05 compared with the former definition). Subsequently, we assessed the incidence of all-cause mortality in 387 consecutive outpatient HF patients (left ventricular ejection fraction ≤45%). In these patients, TSAT ≤19.8% and serum iron ≤13 µmol/L, and not ferritin, were independently associated with mortality.

CONCLUSIONS

A TSAT ≤19.8% or a serum iron ≤13 µmol/L shows the best performance in selecting patients with ID and identifies HF patients at the highest risk of death. Our findings validate the currently used TSAT cutoff of <20% for the identification of ID in HF patients, but question the diagnostic value of ferritin.

Measurement and interpretation of hemoglobin concentration in clinical and field settings: a narrative review

Anemia affects over 800 million women and children globally. Defined as a limited or insufficient functional red blood cell supply in peripheral blood, anemia causes a reduced oxygen supply to tissues and can have serious health consequences for women and children. Hemoglobin (Hb) concentration is most commonly measured for anemia diagnosis. Methods to measure Hb are usually invasive (requiring a blood sample); however, advances in diagnostic and clinical chemistry over the past decade have led to the development of new noninvasive methods. Accurate diagnosis at the individual level is important to identify individuals who require treatment. At the population level, anemia prevalence estimates are often the impetus for national nutrition policies or programs. Thus, it is essential that methods for Hb measurement are sensitive, specific, accurate, and reproducible. The objective of our narrative review is to describe the basic principles, advantages, limitations, and quality control issues related to methods of Hb measurement in clinical and field settings. We also discuss other biomarkers and tests that can help to determine the severity and underlying causes of anemia. In conclusion, there are many established and emerging methods to measure Hb concentration, each with their own advantages, limitations, and factors to consider before use.

Biomarkers of Nutrition for Development (BOND)-Iron Review

This is the fifth in the series of reviews developed as part of the Biomarkers of Nutrition for Development (BOND) program. The BOND Iron Expert Panel (I-EP) reviewed the extant knowledge regarding iron biology, public health implications, and the relative usefulness of currently available biomarkers of iron status from deficiency to overload. Approaches to assessing intake, including bioavailability, are also covered. The report also covers technical and laboratory considerations for the use of available biomarkers of iron status, and concludes with a description of research priorities along with a brief discussion of new biomarkers with potential for use across the spectrum of activities related to the study of iron in human health.The I-EP concluded that current iron biomarkers are reliable for accurately assessing many aspects of iron nutrition. However, a clear distinction is made between the relative strengths of biomarkers to assess hematological consequences of iron deficiency versus other putative functional outcomes, particularly the relationship between maternal and fetal iron status during pregnancy, birth outcomes, and infant cognitive, motor and emotional development. The I-EP also highlighted the importance of considering the confounding effects of inflammation and infection on the interpretation of iron biomarker results, as well as the impact of life stage. Finally, alternative approaches to the evaluation of the risk for nutritional iron overload at the population level are presented, because the currently designated upper limits for the biomarker generally employed (serum ferritin) may not differentiate between true iron overload and the effects of subclinical inflammation.

The relationship between iron bone marrow stores and response to treatment in pediatric acute lymphoblastic leukemia

Iron is an intracellular element whose accumulation in the body is associated with tissue damage. This study examines the effect of iron on pediatric acute lymphoblastic leukemia (ALL) and its "response to treatment." At the end of the first year of treatment, bone marrow iron store (BMIS) was evaluated in children with ALL and the relationship between iron store and minimal residual disease was investigated. Moreover, the 3-year disease-free survival (3-DFS) of patients was determined. Patients' BMIS were compared with that of subjects with normal bone marrow. The study examined 93 children, including 78 Pre-B and 15 T-cell ALL patients. BMIS did not differ between the children with ALL and those with no evidence of cancer. BMIS was increased in 26.6% of patients at the end of the first year of treatment. Drug resistance and BM relapses were more prevalent in cases with high BMIS in both Pre-B and T-cell groups. Bone marrow iron store is not considered a risk factor for childhood ALL. However, high levels of BMIS are associated with poor response to treatment and the risk of relapse. Bone marrow iron store control during treatment can therefore help achieve better outcomes and improve the chances of recovery.

Comparison of Methods Study between a Photonic Crystal Biosensor and Certified ELISA to Measure Biomarkers of Iron Deficiency in Chronic Kidney Disease Patients

The total analytical error of a photonic crystal (PC) biosensor in the determination of ferritin and soluble transferrin receptor (sTfR) as biomarkers of iron deficiency anemia in chronic kidney disease (CKD) patients was evaluated against certified ELISAs. Antigens were extracted from sera of CKD patients using functionalized iron-oxide nanoparticles (fAb-IONs) followed by magnetic separation. Immuno-complexes were recognized by complementary detection Ab affixed to the PC biosensor surface, and their signals were followed using the BIND instrument. Quantification was conducted against actual protein standards. Total calculated error (TEcalc) was estimated based on systematic (SE) and random error (RE) and compared against total allowed error (TEa) based on established quality specifications. Both detection platforms showed adequate linearity, specificity, and sensitivity for biomarkers. Means, SD, and CV were similar between biomarkers for both detection platforms. Compared to ELISA, inherent imprecision was higher on the PC biosensor for ferritin, but not for sTfR. High SE or RE in the PC biosensor when measuring either biomarker resulted in TEcalc higher than the TEa. This did not influence the diagnostic ability of the PC biosensor to discriminate CKD patients with low iron stores. The performance of the PC biosensor is similar to certified ELISAs; however, optimization is required to reduce TEcalc.

Evaluation of a competitive hepcidin ELISA assay in the differential diagnosis of iron deficiency anaemia with concurrent inflammation and anaemia of inflammation in elderly patients

In this study, a competitive hepcidin ELISA assay was evaluated for its ability to differentiate between iron deficiency anaemia with concurrent inflammation and anaemia of inflammation in elderly patients, using the absence of stainable bone marrow iron as the diagnostic criterion for iron deficiency. In addition, correlation coefficients for hepcidin versus C-reactive protein, ferritin and interleukin-6 were determined. The optimal cut-off for hepcidin was 21 μg/L, corresponding to sensitivity and specificity of 100% and 67%, respectively, for iron deficiency. For ferritin, a sensitivity and specificity of 91% and 83%, respectively, correspond to an optimal cut-off of 87 μg/L. Receiver operating characteristics curve analysis revealed that ELISA analysis of hepcidin is not superior to ferritin in the diagnosis of iron deficiency in elderly anaemic patients with concurrent inflammation. Hepcidin shows a strong positive correlation with ferritin, and also correlates positively with C-reactive protein in this patient population.

Bone marrow cell composition and morphology in healthy juvenile female New Zealand White rabbits (Oryctolagus cuniculus)

OBJECTIVE To provide contemporary preliminary guidelines for the morphological evaluation of bone marrow in conjunction with CBC results for healthy juvenile (3- to 6-month-old) female New Zealand White rabbits (Oryctolagus cuniculus). ANIMALS 22 female New Zealand White rabbits. PROCEDURES Each rabbit was sedated, and a blood sample (3 mL) was collected from an ear artery for a CBC, after which the rabbit was euthanized. Within 5 minutes after euthanasia, bone marrow samples were obtained from the femur for cytologic and histologic evaluation. Bone marrow specimens for cytologic evaluation were stained with modified Wright stain, and those for histologic evaluation were stained with either H&E or Prussian blue stain. RESULTS The CBC results were within published reference ranges for all rabbits except 4, each of which had mild leukopenia. Cytologic assessment of bone marrow revealed a median myeloid-to-erythroid ratio of 0.7 and 2.8 megakaryocytes/low-power field (magnification, 100X), and the median percentages of lymphocytes, plasma cells, and macrophages were 11.5%, 0.1%, and 0%, respectively. The myeloid-to-erythroid ratio was not significantly correlated with any CBC variable. On histologic evaluation of bone marrow, the cellularity ranged from 30% to 50%, there were 2.1 to 7.7 megakaryocytes/hpf (magnification, 400X), and no iron stores were visible in H&E or Prussian blue-stained specimens. CONCLUSIONS AND CLINICAL RELEVANCE Results of the present study provided contemporary preliminary guidelines for the evaluation of bone marrow in healthy laboratory rabbits.

Iron for Africa-Report of an Expert Workshop

Scientific experts from nine countries gathered to share their views and experience around iron interventions in Africa. Inappropriate eating habits, infections and parasitism are responsible for significant prevalence of iron deficiency, but reliable and country-comparable prevalence estimates are lacking: improvements in biomarkers and cut-offs values adapted to context of use are needed. Benefits of iron interventions on growth and development are indisputable and outweigh risks, which exist in populations with a high infectious burden. Indeed, pathogen growth may increase with enhanced available iron, calling for caution and preventive measures where malaria or other infections are prevalent. Most African countries programmatically fortify flour and supplement pregnant women, while iron deficiency in young children is rather addressed at individual level. Coverage and efficacy could improve through increased access for target populations, raised awareness and lower cost. More bioavailable iron forms, helping to decrease iron dose, or prebiotics, which both may lower risk of infections are attractive opportunities for Africa. Fortifying specific food products could be a relevant route, adapted to local context and needs of population groups while providing education and training. More globally, partnerships involving various stakeholders are encouraged, that could tackle all aspects of the issue.

Correlation between serum ferritin and bone marrow iron stores

Bone marrow aspirate examination is a gold standard to assess bone marrow iron stores. The correlation between serum ferritin and bone marrow iron has not been established in detail, as the cutoff value for iron stores have not been uniformly established. Ours was a cross-sectional study. Perl's Prussian blue stain was used to stain bone marrow, assessed by Gale's grading. Receiver operating characteristic curve analysis and Spearman's correlation coefficient calculated. Gale's grading revealed iron store deficiency in 26 and sufficiency in 13. Spearman's correlation coefficient of 0.90 showed a significant relation between serum ferritin and bone marrow iron stores. A serum ferritin of 228 pmol/L had high sensitivity and specificity for iron deficiency; our study suggests that this level be taken as the cutoff value to predict iron store deficiency in bone marrow.

Iron homeostasis and serum hepcidin-25 levels in obese children and adolescents: relation to body mass index

BACKGROUND/AIMS

The etiology of the hypoferremia of obesity is unclear. Hepcidin is the body's main regulator of systemic iron (Fe) and has been reported to be elevated in obese patients. Thus, we aimed to assess Fe status and serum hepcidin-25 levels and their relationship with body mass index (BMI) in obese Egyptian children and adolescents.

METHODS

Fifty obese children were compared to 50 age-, sex- and pubertal stage- matched controls. All subjects were subjected to history and anthropometric assessment and measurement of serum Fe, total iron binding capacity (TIBC), ferritin, transferrin saturation (TS), soluble transferrin receptor (sTfR) and hepcidin.

RESULTS

Fe, TS and TIBC were lower, while ferritin, sTfR and hepcidin-25 were higher in obese patients than controls. BMI standard deviation score (SDS) correlated negatively with Fe (r = -0.82, p < 0.01), TS (r = -0.79, p = 0.02) and TIBC (r = -0.69, p = 0.02), and positively with ferritin (r = +0.73, p < 0.001), sTfR (r = +0.80, p < 0.01) and hepcidin (r = +0.95, p < 0.001). Higher BMI SDS and hepcidin were risk factors for iron deficiency (ID).

CONCLUSIONS

Hypoferremia and elevated hepcidin-25 are prevalent in obese children and correlated with BMI SDS. The connection between hepcidin and inflammation could explain the association of ID with obesity.

Severity of anaemia is associated with bone marrow haemozoin in children exposed to Plasmodium falciparum

There are no large-scale ex vivo studies addressing the contribution of Plasmodium falciparum in the bone marrow to anaemia. The presence of malaria parasites and haemozoin were studied in bone marrows from 290 anaemic children attending a rural hospital in Mozambique. Peripheral blood infections were determined by microscopy and polymerase chain reactions. Bone marrow parasitaemia, haemozoin and dyserythropoiesis were microscopically assessed. Forty-two percent (123/290) of children had parasites in the bone marrow and 49% (111/226) had haemozoin, overlapping with parasitaemia in 83% (92/111) of cases. Sexual and mature asexual parasites were highly prevalent (62% gametocytes, 71% trophozoites, 23% schizonts) suggesting their sequestration in this tissue. Sixteen percent (19/120) of children without peripheral infection had haemozoin in the bone marrow. Haemozoin in the bone marrow was independently associated with decreased Hb concentration (P = 0·005) and was more common in dyserythropoietic bone marrows (P = 0·010). The results of this ex vivo study suggest that haemozoin in the bone marrow has a role in the pathogenesis of malarial-anaemia through ineffective erythropoiesis. This finding may have clinical implications for the development of drugs targeted to prevent and treat malarial-anaemia.

Challenges in the diagnosis of iron deficiency in children exposed to high prevalence of infections

BACKGROUND

While WHO guidelines recommend iron supplements to only iron-deficient children in high infection pressure areas, these are rarely implemented. One of the reasons for this is the commonly held view that iron supplementation increases the susceptibility to some infectious diseases including malaria. Secondly, currently used markers to diagnose iron deficiency are also modified by infections. With the objective of improving iron deficiency diagnosis and thus, its management, we evaluated the performance of iron markers in children exposed to high infection pressure.

METHODOLOGY/PRINCIPAL FINDINGS

Iron markers were compared to bone marrow findings in 180 anaemic children attending a rural hospital in southern Mozambique. Eighty percent (144/180) of the children had iron deficiency by bone marrow examination, 88% (155/176) had an inflammatory process, 66% (119/180) had moderate anaemia, 25% (45/180) severe anaemia and 9% (16/180) very severe anaemia. Mean cell haemoglobin concentration had a sensitivity of 51% and specificity of 71% for detecting iron deficiency. Soluble transferrin receptor (sTfR) and soluble transferrin receptor/log ferritin (TfR-F) index (adjusted by C reactive protein) showed the highest areas under the ROC curve (AUC(ROC)) (0.75 and 0.76, respectively), and were the most sensitive markers in detecting iron deficiency (83% and 75%, respectively), but with moderate specificities (50% and 56%, respectively).

CONCLUSIONS/SIGNIFICANCE

Iron deficiency by bone marrow examination was extremely frequent in these children exposed to high prevalence of infections. However, even the best markers of bone marrow iron deficiency did not identify around a quarter of iron-deficient children. Tough not directly extrapolated to the community, these findings urge for more reliable, affordable and easy to measure iron indicators to reduce the burden of iron deficiency anaemia in resource-poor settings where it is most prevalent.

Iron deficiency and heart failure: diagnostic dilemmas and therapeutic perspectives

Iron is a micronutrient essential for cellular energy and metabolism, necessary for maintaining body homoeostasis. Iron deficiency is an important co-morbidity in patients with heart failure (HF). A major factor in the pathogenesis of anaemia, it is also a separate condition with serious clinical consequences (e.g. impaired exercise capacity) and poor prognosis in HF patients. Experimental evidence suggests that iron therapy in iron-deficient animals may activate molecular pathways that can be cardio-protective. Clinical studies have demonstrated favourable effects of i.v. iron on the functional status, quality of life, and exercise capacity in HF patients. It is hypothesized that i.v. iron supplementation may become a novel therapy in HF patients with iron deficiency.

Iron status predicts malaria risk in Malawian preschool children

Introduction

Iron deficiency is highly prevalent in pre-school children in developing countries and an important health problem in sub-Saharan Africa. A debate exists on the possible protective effect of iron deficiency against malaria and other infections; yet consensus is lacking due to limited data. Recent studies have focused on the risks of iron supplementation but the effect of an individual's iron status on malaria risk remains unclear. Studies of iron status in areas with a high burden of infections often are exposed to bias. The aim of this study was to assess the predictive value of baseline iron status for malaria risk explicitly taking potential biases into account.

Methods and materials

We prospectively assessed the relationship between baseline iron deficiency (serum ferritin <30 µg/L) and malaria risk in a cohort of 727 Malawian preschool children during a year of follow-up. Data were analyzed using marginal structural Cox regression models and confounders were selected using causal graph theory. Sensitivity of results to bias resulting from misclassification of iron status by concurrent inflammation and to bias from unmeasured confounding were assessed using modern causal inference methods.

Results and Conclusions

The overall incidence of malaria parasitemia and clinical malaria was 1.9 (95% CI 1.8–2.0) and 0.7 (95% CI 0.6–0.8) events per person-year, respectively. Children with iron deficiency at baseline had a lower incidence of malaria parasitemia and clinical malaria during a year of follow-up; adjusted hazard ratio's 0.55 (95%-CI:0.41–0.74) and 0.49 (95%-CI:0.33–0.73), respectively. Our results suggest that iron deficiency protects against malaria parasitemia and clinical malaria in young children. Therefore the clinical importance of treating iron deficiency in a pre-school child should be weighed carefully against potential harms. In malaria endemic areas treatment of iron deficiency in children requires sustained prevention of malaria.

The ratio of sTfR/ferritin is associated with the expression level of TfR in rat bone marrow cells after endurance exercise

Currently, it is unclear which index of haematological parameters could be used to most easily monitor iron deficiency during endurance training. To address this question, 16 male Wistar rats were randomly assigned to two groups: a sedentary group (n = 8) and an exercised group (n = 8). Initially, animals in the exercise group started running on a treadmill at a rate of 30 m/min, on a 0% grade, for 1 min/session. Running time was gradually increased by 2 min/day. The training plan was one session per day during the initial 2 weeks and two sessions per day during the third to ninth week. At the end of the 9-week experiment, we analysed the blood of the experimental animals for haemoglobin levels, erythrocyte numbers, haematocrit, serum iron levels, total iron binding capacity, transferrin saturation, serum ferritin levels and soluble transferrin receptor (sTfR) levels, and we calculated the ratio of sTfR/ferritin. Erythrocyte numbers, haemoglobin levels and haematocrit values were decreased after 9 weeks of exercise, but sTfR and sTfR/ferritin values were increased (P < 0.01 or P < 0.05). The training regime significantly increased TfR mRNA levels in the bone marrow cells of the exercised rats compared with the sedentary group (1.8 ± 0.5 vs. 1.1 ± 0.2, P < 0.01). These results revealed a significant correlation between TfR levels in the bone marrow cells and the ratio of sTfR/ferritin (r = 0.517; P < 0.01) and sTfR levels (r = 0.206; P < 0.05) in sedentary and exercised rats. In conclusion, we show that sTfR indices and the ratio of sTfR/ferritin could be useful indicators for monitoring iron deficiency during endurance training.

Hepcidin expression in patients with acute leukaemia

BACKGROUND

Hepcidin plays a central role in iron homeostasis, which is regulated by iron stores, the rate of erythropoiesis, inflammation, and hypoxia. Aberrant expression of hepcidin was found in many diseases, however, there is scant information on hepcidin expression in acute leukemia (AL).

MATERIALS AND METHODS

32 patients with AL which diagnosis according to FAB criteria were studied. Serum hepcidin levels, erythropoietin (EPO), interleukin-6 (IL-6), hematological parameters, intracellular and extracellular iron store were evaluated.

RESULTS

Hepcidin was elevated significantly with increased iron storage in patients at onset of AL when erythropoiesis was depressed by blast cells, then decreased significantly with AL remission, while soluble transferrin receptor (sTfR) concentration was elevated. Negative correlations were found between serum hepcidin and erythropoietic markers including RBC, Hb, Ret and sTfR. Positive correlations were shown between hepcidin and ferritin, between hepcidin and ratio of sideroblasts, as well as between hepcidin and IL-6.

CONCLUSIONS

Hepcidin production was regulated by iron stores, inflammation and erythropoietic activity in AL patients. Erythropoietic activity may play the main role among the regulators of hepcidin expresssion.

Chronic anemia and effects of iron supplementation in a research colony of adult Rhesus macaques (Macaca mulatta)

A cohort of rhesus macaques used in neuroscience research was found at routine examinations to have chronic anemia (spun Hct less than 30%). Four anemic (Hct, 24.8% ± 3.4%) and 10 control (39.6% ± 2.9%) macaques were assessed to characterize the anemia and determine probable cause(s); some animals in both groups had cephalic implants. Diagnostic tests included CBC, bone marrow evaluations, iron panels, and serum erythropoietin and hepcidin concentrations. Serum iron and ferritin were 15.8 ± 11.1 μg/dL and 103.8 ± 53.1 ng/mL, respectively, for the anemic group compared with 109.8 ± 23.8 μL/dL and 88.5 ± 41.9 ng/mL, respectively, for the control group. Erythropoietin levels were 16.2 to over 100 mU/mL for the anemic macaques compared with 0 to 1.3 mU/mL for the control group. Hepcidin results were similar in both groups. Because the findings of low iron, high erythropoietin, and normal hepcidin in the anemic macaques supported iron-deficiency anemia or anemia of chronic disease combined with iron-deficiency anemia, a regimen of 4 doses of iron dextran was provided. In treated macaques, Hct rose to 36.3% ± 6.8%, serum iron levels increased to 94.0 ± 41.9 μg/dL, and erythropoietin levels fell to 0.15 to 0.55 mU/mL. Maintenance of normal Hct was variable between macaques and reflected individual ongoing clinical events.

The significance of serum transferrin receptor levels in the diagnosis of the coexistence of anemia of chronic disease and iron deficiency anemia

OBJECTIVE

Iron deficiency anemia is the most common cause of microcytic anemia throughout the world. Ferritin levels are good indicators of iron stores; however, levels may increase irrespective of iron stores in cases of chronic disease. Therefore, it is difficult to diagnose iron deficiency anemia coexisting with anemia of chronic disease.

MATERIALS AND METHODS

To determine the level of transferrin receptor in subjects, 30 patients with iron deficiency anemia, 30 patients with anemia of chronic disease and 30 patients with both diseases were included in the study.

RESULTS

Mean serum transferrin receptor levels were 5.99±2.98 mg/L in the iron deficiency anemia group, 1.90±1.15 mg/L in the anemia of chronic disease group and 3.07±0.90 mg/L in the combination group. Comparing groups with each other revealed significant differences (p<0.05).

CONCLUSION

It is concluded that the assessment of serum transferrin receptor levels is a useful method for the diagnosis of iron deficiency anemia in patients.

Pathophysiological mechanisms of severe anaemia in Malawian children

BACKGROUND

Severe anaemia is a major cause of morbidity and mortality in African children. The aetiology is multi-factorial, but interventions have often targeted only one or a few causal factors, with limited success.

METHODS AND FINDINGS

We assessed the contribution of different pathophysiological mechanisms (red cell production failure [RCPF], haemolysis and blood loss) to severe anaemia in Malawian children in whom etiological factors have been described previously. More complex associations between etiological factors and the mechanisms were explored using structural equation modelling. In 235 children with severe anaemia (haemoglobin<3.2 mMol/L [5.0 g/dl]) studied, RCPF, haemolysis and blood loss were found in 48.1%, 21.7% and 6.9%, respectively. The RCPF figure increased to 86% when a less stringent definition of RCPF was applied. RCPF was the most common mechanism in each of the major etiological subgroups (39.7-59.7%). Multiple aetiologies were common in children with severe anaemia. In the final model, nutritional and infectious factors, including malaria, were directly or indirectly associated with RCPF, but not with haemolysis.

CONCLUSION

RCPF was the most common pathway leading to severe anaemia, from a variety of etiological factors, often found in combination. Unlike haemolysis or blood loss, RCPF is a defect that is likely to persist to a significant degree unless all of its contributing aetiologies are corrected. This provides a further explanation for the limited success of the single factor interventions that have commonly been applied to the prevention or treatment of severe anaemia. Our findings underline the need for a package of measures directed against all of the local aetiologies of this often fatal paediatric syndrome.

New cut-off values for ferritin and soluble transferrin receptor for the assessment of iron deficiency in children in a high infection pressure area

Background:

Due to the potential risk of iron supplementation in iron replete children, it is important to properly identify children who may require iron supplementation. However, assessment of the iron status has proven to be difficult, especially in children living in areas with high infection pressure (including malaria).

Aims and Methods:

Biochemical iron markers were compared to bone marrow iron findings in 381 Malawian children with severe anaemia.

Results:

Soluble transferrin receptor/log ferritin (TfR-F index), using a cut-off of 5.6, best predicted bone marrow iron stores deficiency (sensitivity 74%, specificity 73%, accuracy 73%). In order to improve the diagnostic accuracy of ferritin or sTfR as a stand-alone marker, the normal cut-off value needed to be increased by 810% and 83% respectively. Mean cell haemoglobin concentration (MCHC), using a cut-off of 32.1 g/dl, had a sensitivity of 67% and specificity of 64% for detecting iron stores deficiency.

Conclusion:

TfR-F index incorporated the high sensitivity of sTfR, a proxy for cellular iron need, and the high specificity of ferritin, a proxy for iron stores. In areas with a high infection pressure, the TfR-F index best predicted iron deficiency. However, in settings where diagnostic tests are limited, MCHC may be an acceptable alternative screening test.