Guideline for the laboratory diagnosis of iron deficiency in adults (excluding pregnancy) and children

Iron deficiency and supplementation in heart failure

Non-anaemic iron deficiency (NAID) is a strategic target in cardiovascular medicine because of its association with a range of adverse effects in various conditions. Endeavours to tackle NAID in heart failure have yielded mixed results, exposing knowledge gaps in how best to define 'iron deficiency' and the handling of iron therapies by the body. To address these gaps, we harness the latest understanding of the mechanisms of iron homeostasis outside the erythron and integrate clinical and preclinical lines of evidence. The emerging picture is that current definitions of iron deficiency do not assimilate the multiple influences at play in patients with heart failure and, consequently, fail to identify those with a truly unmet need for iron. Additionally, current iron supplementation therapies benefit only certain patients with heart failure, reflecting differences in the nature of the unmet need for iron and the modifying effects of anaemia and inflammation on the handling of iron therapies by the body. Building on these insights, we identify untapped opportunities in the management of NAID, including the refinement of current approaches and the development of novel strategies. Lessons learned from NAID in cardiovascular disease could ultimately translate into benefits for patients with other chronic conditions such as chronic kidney disease, chronic obstructive pulmonary disease and cancer.

Iron deficiency in children with a focus on inflammatory conditions

Iron deficiency (ID) tends to be overlooked compared with anemia. However, its prevalence is estimated to be twice as high as that of ID anemia, and ID without anemia can be accompanied by clinical and functional impairments. The symptoms of ID are nonspecific, such as fatigue and lethargy, but can lead to neurodevelopmental disorders in children, restless legs syndrome, and recurrent infections due to immune system dysregulation. In particular, the risk of ID is high in the context of chronic inflammatory diseases (CIDs) due to the reaction of various cytokines and the resulting increase in hepcidin levels; ID further exacerbates these diseases and increases mortality. Therefore, the diagnosis of ID should not be overlooked through ID screening especially in high-risk groups. Ferritin and transferrin saturation levels are the primary laboratory parameters used to diagnose ID. However, as ferritin levels respond to inflammation, the diagnostic criteria differ among guidelines. Therefore, new tools and criteria for accurately diagnosing ID should be developed. Treatment can be initiated only with an accurate diagnosis. Oral iron is typically the first-line treatment for ID; however, the efficacy and safety of intravenous iron have recently been recognized. Symptoms improve quickly after treatment, and the prognosis of accompanying diseases can also be improved. This review highlights the need to improve global awareness of ID diagnosis and treatment, even in the absence of anemia, to improve the quality of life of affected children, especially those with CIDs.

Algorithm of differential diagnosis of anemia involving laboratory medicine specialists to advance diagnostic excellence

OBJECTIVES

Anemia is a severe global public health issue. Testing practices for anemia suggest overuse of screening laboratory tests and misinterpretation of studies even in "easy-to-diagnose" underlying causes, leading to late diagnoses and missed treatment opportunities. We aimed to develop a complete and efficient algorithm for clinical pathologists and laboratory medicine physicians for the differential diagnosis of anemia.

METHODS

Comprehensive literature search encompassing original articles, studies, reviews, gold standard books, and other evidence.

RESULTS

We created a complex algorithm, primarily for clinical pathology/laboratory use, that explores all major and several rare causes of anemia in an efficient and evidence-based manner. The algorithm includes gold-standard diagnostic laboratory tests available in most clinical laboratories and indices that can be easily calculated to provide an evidence-based differential diagnosis of anemia.

CONCLUSIONS

The diagnostic strategy combines previously available diagnostic tests and protocols in an efficient order. Clinical pathologists following the algorithm can independently provide valuable diagnostic support for healthcare providers. Clinical pathologists providing complete differential diagnostic services with the proposed algorithm may create an opportunity for an advanced diagnostic service that supports diagnostic excellence and helps patients receive a timely diagnosis and early treatment opportunities.

Diagnostic performance of automated red cell parameters in predicting bone marrow iron stores

OBJECTIVES

The aim of the study was to determine the diagnostic performance of novel automated red cell parameters for estimating bone marrow iron stores.

METHODS

The study was a retrospective single-centre study based on data from an automated haematology analyser and results of bone marrow iron staining. Red cell parameters were measured on a Sysmex XN-series haematology analyser. Bone marrow iron stores were assessed semiquantitatively by cytochemical reaction according to Perls.

RESULTS

The analysis included 429 bone marrow aspirate smears from 393 patients. Median age of patients was 67 years, 52 % of them were female. The most common indication for bone marrow examination was a plasma cell dyscrasia (n=104; 24 %). Median values of percentage of hypochromic and hyperchromic red blood cells (%HYPO-He, %HYPER-He), reticulocyte haemoglobin equivalent (RET-He) and microcytic red blood cells (MicroR) were statistically significantly different between cases with iron deplete and iron replete bone marrow. In a logistic regression model, ferritin was the best predictor of bone marrow iron stores (AUC=0.891), outperforming RET-He and %HYPER-He (AUC=0.736 and AUC=0.722, respectively). In a combined model, ferritin/MicroR index achieved the highest diagnostic accuracy (AUC=0.915), outperforming sTfR/log ferritin index (AUC=0.855).

CONCLUSIONS

While single automated red cell parameters did not show improved diagnostic accuracy when compared to traditional iron biomarkers, a novel index ferritin/MicroR has the potential to outperform ferritin and sTfR/log ferritin index for predicting bone marrow iron stores. Further research is needed for interpretation and implementation of novel parameters and indices, especially in the context of unexplained anaemia and myelodysplastic syndromes.

Clinical and biochemical footprints of inherited metabolic disease. XVI. Hematological abnormalities

Many classical inherited metabolic diseases (IMDs) are associated with significant hematological complications such as anemia or thrombosis. While these may not be the prominent presenting feature of these conditions, management of these issues is important for optimal outcomes in people with IMDs. Some disorders that are included in the nosology of inherited metabolic disorders, such as inherited disorders of red cell energy metabolism, have purely hematological features, and have typically been cared for by a hematologist. In the 16th issue of the Footprints series, we identified 265 IMDs associated with hematological abnormalities. We review the major hematological manifestations of IMDs, suggest further investigation of hematological findings, and discuss treatment options available for specific hematological complications of IMDs.

The Burden of Childhood Iron Deficiency Anemia in a Developed Country: A Croatian Tertiary Care Center Experience

BACKGROUND

Given the high prevalence of unrecognized iron deficiency anemia (IDA) in Croatia and its negative impact on children's somatic and neurological outcomes, a comprehensive preventive and treatment approach is a necessity.  Methods: This was an observational, cross-sectional study of pediatric patients referred to the Children's Hospital Zagreb, Croatia, from 2017 to 2021, for IDA. Epidemiological and clinical data were extracted. Laboratory workup and therapeutic actions in the primary and tertiary care settings were recorded. The need for transfusion, parenteral iron therapy, and hospital admission was noted.

RESULTS

A total of 299 patients (52.2% female, median five years) were seen by the hematologist in the five-year study period. Almost half (45.1%) were referred by the primary care pediatrician. Only half of the patients (56.6%) received oral iron therapy prior to referral. The preferred preparation was Dextriferron (67.7%) during the mean period of 5.8 months, but more than one-third of the patients (36.5%) were non-compliant. Every 10th child seen by the hematologist for IDA was admitted to the hospital; 6.4% required transfusion therapy, and in only one patient, parenteral iron was administered.  Conclusions: The results of this survey established that IDA still represents an excessive burden in a tertiary care setting of a high-income country. Therefore, consistent implementation of national guidelines and additional education of primary healthcare providers is crucial to ameliorate this significant public health concern.

Single shot of intravenous iron in cardiac surgery: The ICARUS study

BACKGROUND

Iron deficiency (ID), with or without anemia, is commonly observed among patients scheduled for cardiac surgery. We investigated if screening ID in the immediate preoperative period and treating ID patients regardless of anemia could reduce perioperative transfusion requirements.

METHODS

This is an observational single-center propensity score-matched study including candidates to elective cardiac surgery prospectively and retrospectively enrolled. Prospectively enrolled patients were screened for ID at hospital admission: if ferritin was ≤100 μg/L or ≤ 300 μg/L with transferrin saturation index ≤20% they received intravenous ferric carboxymaltose, B12-vitamin, and folic acid. A retrospective series of patients not screened for ID and matched for gender, type of surgery, BMI, Goudie transfusion risk score, hemoglobin level, and red blood cell (RBC) indices, served as controls. The primary outcome was the proportion of patients requiring ≤1 packed RBC (pRBC) unit within day 7 or discharge The main secondary outcomes were intraoperative and postoperative pRBC transfusions, duration of hospitalization, and cost-effectiveness of ID screening and treatment.

RESULTS

We included 479 prospective and 833 retrospective cases: 442 patients screened for ID and 442 matched controls with unknown iron status were analyzed. ID was observed in 196 patients (44.3%) and iron was administered 1 day (IQR 1-2) before surgery. Overall, 76.9% of patients in the prospective group and 69.7% of controls received ≤1 pRBC transfusion (p = 0.014). The risk for multiple transfusions was lower in patients screened for ID (OR 0.689, 95% CI 0.510-0.930). Despite similar Hb levels at day 7, patients in the prospective group received fewer postoperative pRBC transfusions (p < 0.001) and had a shorter hospital length of stay (p < 0.001). Globally, hospitalization costs were lower in patients screened and treated for ID.

CONCLUSIONS

Short-term pre-operative iron therapy is associated with a reduction in postoperative transfusions in anemic and non-anemic ID cardiac surgery patients and has a favorable impact on hospitalization costs.

CLINICAL TRIAL REGISTRATION

NCT04744181.

Anemia of chronic diseases: current state of the problem and perspectives

Anemia of chronic diseases is a condition, that accompanies several chronic conditions, that have inflammation as an underlying cause. The article covers current concepts of pathogenesis, evaluation and treatment of this type of anemia. The new perspectives in the development of investigational methods and treatment are discussed. The new methods of iron deficiency assessment in patients with systemic inflammation are discussed separately.

The global prevalence and ethnic heterogeneity of iron-refractory iron deficiency anaemia

BACKGROUND

Iron-refractory iron deficiency anaemia (IRIDA) is an autosomal recessive iron deficiency anaemia caused by mutations in the TMPRSS6 gene. Iron deficiency anaemia is common, whereas IRIDA is rare. The prevalence of IRIDA is unclear. This study aimed to estimate the carrier frequency and genetic prevalence of IRIDA using Genome Aggregation Database (gnomAD) data.

METHODS

The pathogenicity of TMPRSS6 variants was interpreted according to the American College of Medical Genetics and Genomics (ACMG) and the Association for Molecular Pathology (AMP) standards and guidelines. The minor allele frequency (MAF) of TMPRSS6 gene disease-causing variants in 141,456 unique individuals was examined to estimate the global prevalence of IRIDA in seven ethnicities: African/African American (afr), American Admixed/Latino (amr), Ashkenazi Jewish (asj), East Asian (eas), Finnish (fin), Non-Finnish European (nfe) and South Asian (sas). The global and population-specific carrier frequencies and genetic prevalence of IRIDA were calculated using the Hardy-Weinberg equation.

RESULTS

In total, 86 pathogenic/likely pathogenic variants (PV/LPV) were identified according to ACMG/AMP guideline. The global carrier frequency and genetic prevalence of IRIDA were 2.02 per thousand and 1.02 per million, respectively.

CONCLUSIONS

The prevalence of IRIDA is greater than previous estimates.

Eligibility Considerations for Female Whole Blood Donors: Hemoglobin Levels and Iron Status in a Nationally Representative Population

Blood collection from minority populations improves the transfusion support of patients with sickle cell disease and thalassemia, but efforts are challenged by high deferral rates for hemoglobin (Hb) eligibility thresholds. This study sought to evaluate hemoglobin and iron status of a representative US female population to assess the suitability of 12.0 g/dL as minimum hemoglobin. Data were extracted from the National Health and Nutrition Examination Surveys (NHANES), 1999-2010. A national sample designed to reflect potential female blood donors (weight ≥110 lbs, not pregnant, no infectious marker reactivity, and no blood donation in past year) aged 16 to 49 years was analyzed for Hb and serum ferritin (SF) measures by race/ethnicity (N = 6937). Mean Hb and SF and the prevalence of iron deficiency ([ID] SF<12 ng/mL and SF<26 ng/mL) and low Hb (<12.5 g/dL and <12.0 g/dL) were estimated. Multivariable modified Poisson regression compared the prevalence for ID or low Hb at each cutoff by race/ethnicity. Mean SF values were higher and ID prevalence was lower in Non-Hispanic (NH) White (SF = 45.3 ng/mL, SF<12 ng/mL = 8.2%) than NH Black (SF = 39.6 ng/mL, SF<12 ng/mL = 14.2%) and Hispanic (SF = 36.5 ng/mL, SF<12 ng/mL = 12.7%) females. Compared to NH White females (13.7 g/dL), mean Hb was lower in NH Black (12.6 g/dL) and Hispanic females (13.4 g/dL). The percentage with Hb<12.5 g/dL was >4 times greater in NH Black (39.1%) and >2 times greater in Hispanic females (16.5%) compared to NH White (8.6%). Within 0.5 g/dL incremental categories of Hb, NH Black had higher mean SF levels and lower prevalence of SF<12 ng/mL or <26 ng/mL compared to NH White and Hispanic females. At Hb of 12.0 to 12.4g/dL, NH Black females had better measures of iron status (SF = 39.1 ng/mL, %SF<12 ng/mL = 12.0%) than NH White (SF = 33.6 ng/mL, %SF<12 ng/mL=15.8%) and Hispanic (SF = 30.4 ng/mL, %SF<12 ng/mL=15.5%) females whose Hb was 12.5 to 12.9 g/dL. Adjusting for age and Hb, the prevalence ratio for low SF was significantly lower in NH Black compared to NH White females at both SF<26 ng/mL (adjusted prevalence ratio [aPR] = 0.83, 95%CI = 0.76-0.92) and SF<12 ng/mL (aPR = 0.66, 95%CI = 0.52-0.83). NH Black females with Hb 12.0 to 12.4g/dL have better iron stores than NH White and Hispanic females whose Hb is 12.5 to 12.9 g/dL. The distribution of Hb and iron may support the safe collection of blood for female donors below the current Hb eligibility requirement of 12.5 g/dL.

UK NEQAS Haematology pilot scheme: Reticulocyte haemoglobin content quantitation

INTRODUCTION

Established parameters for the investigation of suspected iron deficiency have recognized limitations that affect their sensitivity and specificity. Reticulocyte haemoglobin content (RHC) is an early biomarker of iron deficiency or restriction, which also demonstrates response to iron therapy. RHC parameters are offered on all major automated haematology analysers. There is no external quality assessment (EQA) for RHC in the UK, restricting its wider clinical application. The UK National External Quality Assessment Scheme (UKNEQAS) for Haematology has completed a pilot study on the use of stabilized blood for RHC EQA.

METHODS

Blood was obtained from two JAK2 V617F mutation-positive, polycythaemia vera patients undergoing regular venesection, and from a healthy volunteer donor. Aliquots of each donation were distributed to users of Abbott, Horiba, Siemens and Sysmex automated analysers for RHC analysis on days 1, 3, 5 and 7.

RESULTS

Results were received from 20 laboratories using four different platforms. The daily mean and standard deviation (SD) were calculated for each aliquot, by day of analysis and platform. With RHC there was no significant within-platform difference (p > 0.5) between testing days, although there were statistically significant differences (p < 0.001) between different platforms. The greatest difference was seen between Abbott MCHr and Horiba RhCc (-6.14 ± 1.25 pg). Despite inter-platform differences, it was possible to define iron deficient, borderline, and normal cut-offs to classify 95% of results correctly.

CONCLUSIONS

The results demonstrate that it is possible to provide RHC EQA material using UKNEQAS standard procedures. The results are clinically relevant but indicate a requirement for inter-user comparison.

Management of iron deficiency in chronic heart failure

Iron deficiency is frequent in patients with chronic heart failure (CHF) with a prevalence of 50%, and its frequency varies depending on the study groups. The presence of iron deficiency limits erythropoiesis, leading to the development of anemia over time in patients with CHF, regardless of gender, race, and left ventricular ejection fraction (LVEF). Observational studies demonstrate a higher prevalence of iron deficiency in women and in patients with higher NYHA (New York Heart Association) functional class, decreased LVEF, increased brain natriuretic peptide (NT-proBNP), or increased high-sensitivity C-reactive protein. Iron deficiency and anemia in patients with CHF are independently associated with a decreased exercise capacity, hospitalizations for CHF, an increase in overall mortality and mortality from cardiovascular diseases. The clinical significance of iron deficiency requires the need to diagnose iron metabolism in all patients with CHF. Current guidelines for the diagnosis and treatment of CHF indicate the need to determine the level of ferritin and saturation of transferrin in all patients with a suspected diagnosis of heart failure. The use of oral iron therapy in patients with CHF demonstrates its low efficacy in correcting this condition according to the clinical trials. At the same time the use of intravenous iron therapy is safe and improves symptoms, exercise capacity and quality of life in patients with heart failure with reduced ejection fraction and iron deficiency, which has been shown both in international placebo-controlled trials and meta-analyses. The use of iron carboxymaltose should improve CHF symptoms, exercise capacity and quality of life in patients with CHF and LVEF45%. Intravenous iron therapy has also been shown to reduce readmissions for CHF in patients with an LVEF50% who have recently been hospitalized for worsening CHF.

Is Iron Deficiency Anemia still Becoming Community Health Problem in Urban Area?

Background: Iron deficiency anemia is one of the common public health problems that found in various countries, including Indonesia. The incidence of iron deficiency anemia does not only occur in rural areas but also in urban areas. Iron deficiency that occurs in adolescent girls with or without anemia has a negative impact on immune function, growth and physical and mental development. Purpose: To determine the incidence of anemia in adolescent girls in urban areas. Patients and methods: This study was an observational study with a cross sectional design. The research subjects were 52 young women aged 15-25 years living in the city of Semarang, Central Java. The subject will be taken a blood sample to check the complete blood profile and iron status, namely serum ferritin, serum iron, and serum TIBC (total iron binding capacity). Research data analysis was carried out using a computer program. Results: The prevalence of iron deficiency anemia among female adolescents in urban areas in this study was 13.4% while adolescent girls who experienced iron deficiency without anemia were 13.4%. Conclusion: Iron deficiency anemia can occur in urban areas with a prevalence > 5%.  

Daily versus every other day oral iron supplementation in patients with iron deficiency anemia (DEODO): study protocol for a phase 3 multicentered, pragmatic, open-label, pilot randomized controlled trial

BACKGROUND

Iron deficiency anemia (IDA) accounts for the majority of anemia cases across the globe and can lead to impairments in both physical and cognitive functioning. Oral iron supplementation is the first line of treatment to improve the hemoglobin level for IDA patients. However, gaps still exist in understanding the appropriate dosing regimen of oral iron. The current trial proposes to evaluate the feasibility of performing this study to examine the effectiveness and side-effect profile of oral iron once daily versus every other day.

METHODS

In this open-label, pilot, feasibility, randomized controlled trial, 52 outpatients over 16 years of age with IDA (defined as hemoglobin < 12.0 g/dL in females and < 13.0 g/dL in males and ferritin < 30 mcg/L) will be enrolled across two large academic hospitals. Participants are randomized in a 1:1 ratio to receive 300 mg oral ferrous sulfate (60 mg of elemental iron) either every day or every other day for 12 weeks. Participants are excluded if they are as follows: (1) pregnant and/or currently breastfeeding, (2) have a disease history that would impair response to oral iron (e.g., thalassemia, celiac disease), (3) intolerant and/or have an allergy to oral iron or vitamin C, (4) on new anticoagulants in the past 6 months, (5) received IV iron therapy in the past 12 weeks, (6) have surgery, chemotherapy, or blood donation planned in upcoming 12 weeks, (7) a creatinine clearance < 30 mL/min, or (8) hemoglobin less than 8.0 g/dL with active bleeding. The primary outcome is feasibility to enroll 52 participants in this trial over a 2-year period to determine the effectiveness of daily versus every other day oral iron supplementation on hemoglobin at 12 weeks post-initiation and side-effect profile.

DISCUSSION

The results of this trial will provide additional evidence for an appropriate dosing schedule for treating patients with IDA with oral iron supplementation. Additional knowledge will be gained on how the dosing regimen of oral iron impacts quality of life and hemoglobin repletion in IDA patients. If this trial is deemed feasible, it will inform the development and implementation of a larger multicenter definitive trial.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT03725384 . Registered 31 October 2018.

British Society of Gastroenterology guidelines for the management of iron deficiency anaemia in adults

Iron deficiency anaemia (IDA) is a major cause of morbidity and burden of disease worldwide. It can generally be diagnosed by blood testing and remedied by iron replacement therapy (IRT) using the oral or intravenous route. The many causes of iron deficiency include poor dietary intake and malabsorption of dietary iron, as well as a number of significant gastrointestinal (GI) pathologies. Because blood is iron-rich it can result from chronic blood loss, and this is a common mechanism underlying the development of IDA-for example, as a consequence of menstrual or GI blood loss.Approximately a third of men and postmenopausal women presenting with IDA have an underlying pathological abnormality, most commonly in the GI tract. Therefore optimal management of IDA requires IRT in combination with appropriate investigation to establish the underlying cause. Unexplained IDA in all at-risk individuals is an accepted indication for fast-track secondary care referral in the UK because GI malignancies can present in this way, often in the absence of specific symptoms. Bidirectional GI endoscopy is the standard diagnostic approach to examination of the upper and lower GI tract, though radiological scanning is an alternative in some situations for assessing the large bowel. In recurrent or refractory IDA, wireless capsule endoscopy plays an important role in assessment of the small bowel.IDA may present in primary care or across a range of specialties in secondary care, and because of this and the insidious nature of the condition it has not always been optimally managed despite the considerable burden of disease- with investigation sometimes being inappropriate, incorrectly timed or incomplete, and the role of IRT for symptom relief neglected. It is therefore important that contemporary guidelines for the management of IDA are available to all clinicians. This document is a revision of previous British Society of Gastroenterology guidelines, updated in the light of subsequent evidence and developments.