Reticulocyte hemoglobin content

Reference values for reticulocyte haemoglobin equivalent in healthy Chinese children under 5 years and its associations with various blood parameters

BACKGROUND

Reticulocyte haemoglobin equivalent (RET-He) is a useful tool for evaluating recent iron usage irrespective of inflammatory status. This study aims to establish a reference for RET-He among Hong Kong healthy children under the age of 5 years and to investigate the association between RET-He and various blood parameters.

METHODS

A total of 946 children aged 2-48 months from July 2019 to December 2022 were recruited in this cross-sectional study. The RET-He and other haematological parameters were measured by the haematology analyser from Sysmex XN-9100/XN-1500. The ferritin test was performed with the electrochemiluminescence immunoassay. Interval 2.5th percentile to 97.5th percentile represented the normal RET-He ranges. Linear multiple regression analysis was performed to examine the relation between RET-He and various blood parameters. Receiver-operating characteristic curve analysis revealed the sensitivity and specificity of RET-He in identifying iron deficiency.

RESULTS

The RET-He in the study population was approximately normally distributed. The age-specific lower limit of RET-He ranges from 25.81 pg (25-36 months) to 27.15 pg (13-24 months). RET-He was found to be lower in the age group 2-6 months (mean=29.47 pg) and 7-12 months (mean=29.41 pg). Changes in RET-He and haemoglobin in relation to age were observed in both sexes (both p<0.001). RET-He was influenced by age, some red blood cell parameters and reticulocyte concentrations (all p<0.05). A cut-off value of RET-He ≤27.8 pg was determined for identifying iron deficiency.

CONCLUSIONS

RET-He levels varied with age, with a relatively lower level in infants than in other age groups. The value below the age-specific lower limit of the reference range of RET-He can be used as a limit for preliminary iron-deficiency screening.

Anemia of Chronic Kidney Disease-A Narrative Review of Its Pathophysiology, Diagnosis, and Management

Anemia is one of the most common chronic kidney disease (CKD) complications. It negatively affects patients' quality of life and clinical outcomes. The pathophysiology of anemia in CKD involves the interplay of various factors such as erythropoietin (EPO) deficiency, iron dysregulation, chronic inflammation, bone marrow dysfunction, and nutritional deficiencies. Despite recent advances in understanding this condition, anemia still remains a serious clinical challenge in population of patients with CKD. Several guidelines have been published with the aim to systematize the diagnostic approach and treatment of anemia; however, due to emerging data, many recommendations vary between publications. Recent studies indicate a potential of novel biomarkers to evaluate anemia and related conditions such as iron deficiency, which is often present in CKD patients. Our article aims to summarize the pathophysiology of anemia in CKD, as well as the diagnosis and management of this condition, including novel therapeutic approaches such as hypoxia-inducible factor-prolyl hydroxylase inhibitors (HIF-PHI). Understanding these complex subjects is crucial for a targeted approach to diagnose and treat patients with anemia in CKD effectively.

Current approach to the management of preoperative iron deficiency anemia in colorectal cancer patients: a review of literature

<b>Introduction:</b> The prevalence of preoperative anemia is the highest in the group of colorectal cancer (CRC) patients and may reach over 75%. The prevalence of anemia in CRC patients increases even further following surgery. Approximately 75-80% of anemic CRC patients present with absolute or functional iron deficiency (ID). Preoperative anemia constitutes an independent risk factor for allogeneic blood transfusion (ABT), postoperative complications, prolonged length of hospital stay, and increased mortality. ABT is itself associated with increased morbidity and mortality.<b>Aim:</b> The aim of this review article was to present the pathophysiology and the current approach to the diagnostics and treatment of preoperative iron deficiency anemia (IDA) in CRC patients.<b>Material and methods:</b> Extensive search of medical literature databases was performed (Pubmed, Embase). The key words that were used were as follows: CRC, colorectal surgery, ID, IDA, intravenous iron, Patient Blood Management (PBM).<b>Results:</b> There are several laboratory parameters that can be used for IDA diagnosis, however, the simplest and most cost- -effective is reticulocyte hemoglobin equivalent (RET-He). Pathophysiologic features of IDA in CRC patients favor treatment with intravenous, as opposed to oral, iron formulations. Applying PBM strategies minimizes the exposure to ABT.<b>Conclusions:</b> Preoperative IDA is highly prevalent among CRC patients. Preoperative anemia is an independent risk factor for ABT, increased morbidity and mortality, as well as prolonged hospital length of stay. The same negative consequences are associated with ABT. Therefore, preoperative IDA in CRC patients needs to be screened for, diagnosed, and treated before surgery. Effective treatment of preoperative IDA in CRC patients is with intravenous iron formulations. ABT should be the treatment of last resort due to the risk of negative clinical consequences, including an increased rate of cancer recurrence.

Reticulocyte hemoglobin equivalent as a marker to assess iron deficiency: A large pediatric tertiary care hospital study

INTRODUCTION

Detection of iron deficiency (ID) remains challenging. We aimed to evaluate the performance of reticulocyte hemoglobin equivalent (Ret-He) as a potential diagnostic marker to assess ID and iron deficiency anemia (IDA) in a large pediatric cohort.

METHODS

A total of 3158 patients (aged 15 days to 19 years with a median age of 8.5 years; 60.2% female) were retrospectively studied. Statistical analysis was performed (a) to evaluate relationship of Ret-He with other relevant complete blood count and iron panel parameters; (b) to compare the levels of Ret-He in ID and IDA groups to a control group; and (c) to assess sensitivity and specificity of Ret-He in ID, IDA, and anemia without ID groups.

RESULTS

Ret-He values were significantly positively correlated to ferritin and transferrin saturation (TSAT). The median Ret-He was significantly lower in ID. A Ret-He cutoff of ≤30.0 pg distinguished cases of ID from the control group with a sensitivity of 90.2%, specificity of 59.5%, and area under curve (AUC) of 0.88. Ret-He showed better diagnostic performance in the IDA group and acceptable performance for ID without anemia. The sensitivity, specificity, and AUC were 90.1%, 80.9%, and 0.93 for IDA at cutoff value of ≤27.4 pg, and 80.8%, 51.1%, and 0.70 for ID without anemia at cutoff value of ≤30.8 pg, respectively.

CONCLUSION

Our large pediatric tertiary care hospital study demonstrates that Ret-He is a reliable marker to help confirm IDA in pediatric population. However, further studies are needed for its use to capture the early stages of ID.

Perspectives on Iron Deficiency as a Cause of Human Disease in Global Public Health

Iron (Fe) is a necessary trace element in numerous pathways of human metabolism. Therefore, Fe deficiency is capable of causing multiple health problems. Apart from the well-known microcytic anemia, lack of Fe can cause severe psychomotor disorders in children, pregnant women, and adults in general. Iron deficiency is a global health issue, mainly caused by dietary deficiency but aggravated by inflammatory conditions. The challenges related to this deficiency need to be addressed on national and international levels. This review aims to summarize briefly the disease burden caused by Fe deficiency in the context of global public health and aspires to offer some hands-on guidelines.

Plasmodium yoelii iron transporter PyDMT1 interacts with host ferritin and is required in full activity for malarial pathogenesis

BACKGROUND

The rapid reproduction of malaria parasites requires proper iron uptake. However, the process of iron absorption by parasites is rarely studied. Divalent metal transporter (DMT1) is a critical iron transporter responsible for uptaking iron. A homolog of human DMT1 exists in the malaria parasite genome, which in Plasmodium yoelii is hereafter named PyDMT1.

RESULTS

PyDMT1 knockout appears to be lethal. Surprisingly, despite dwelling in an iron-rich environment, the parasite cannot afford to lose even partial expression of PyDMT1; PyDMT1 hypomorphs were associated with severe growth defects and quick loss of pathogenicity. Iron supplementation could completely suppress the defect of the PyDMT1 hypomorph during in vitro culturing. Genetic manipulation through host ferritin (Fth1) knockout to increase intracellular iron levels enforced significant growth inhibition in vivo on the normal parasites but not the mutant. In vitro culturing with isolated ferritin knockout mouse erythrocytes completely rescued PyDMT1-hypomorph parasites.

CONCLUSION

A critical iron requirement of malaria parasites at the blood stage as mediated by this newly identified iron importer PyDMT1, and the iron homeostasis in malarial parasites is finely tuned. Tipping the iron balance between the parasite and host will efficiently kill the pathogenicity of the parasite. Lastly, PyDMT1 hypomorph parasites were less sensitive to the action of artemisinin.

Hemoglobin and Its Z Score Reference Intervals in Febrile Children: A Cohort Study of 98,572 Febrile Children

OBJECTIVES

Febrile disease and age of children were associated with a variation in hemoglobin (Hb) level. Both CRP and Hb serve as laboratory markers that offer valuable insights into a patient's health, particularly in relation to inflammation and specific medical conditions. Although a direct correlation between CRP and Hb levels is not established, the relationship between these markers has garnered academic attention and investigation. This study aimed to determine updated reference ranges for Hb levels for age and investigated its correlation with CRP in febrile children under the age of 18.

METHODS

This is a cohort study of in Chang Gung Memorial Hospitals conducted from January 2010 to December 2019. Blood samples were collected from 98,572 febrile children who were or had been admitted in the pediatric emergency department. The parameters of individuals were presented as the mean ± standard deviation or 2.5th and 97.5th percentiles. We also determined the variation of Hb and Z score of Hb between CRP levels in febrile children.

RESULT

We observed that the Hb levels were the highest immediately after birth and subsequently underwent a rapid decline, reaching their lowest point at around 1-2 months of age, and followed by a steady increment in Hb levels throughout childhood and adolescence. In addition, there was a significant and wide variation in Hb levels during the infant period. It revealed a significant association between higher CRP levels and lower Hb levels or a more negative Z score of Hb across all age subgroups. Moreover, in patients with bacteremia, CRP levels were higher, Hb concentrations were lower, and Z scores of Hb were also lower compared to the non-bacteremia group. Furthermore, the bacteremia group exhibited a more substantial negative correlation between CRP levels and a Z score of Hb (r = -0.41, p < 0.001) compared to the non-bacteremia group (r = -0.115, p < 0.049).

CONCLUSION

The study findings revealed that the Hb references varied depending on the age of the children and their CRP levels. In addition, we established new reference values for Hb and its Z scores and explore their relationship with CRP. It provides valuable insights into the Hb status and its potential association with inflammation in febrile pediatric patients.

Defining an optimal cut-off point for reticulocyte hemoglobin as a marker for iron deficiency anemia: An ROC analysis

Reticulocyte hemoglobin (CHr) is a measure of the amount of hemoglobin in reticulocytes and a marker of cell hemoglobinization. In this study, we aimed to find the optimal cut-off point for reticulocyte hemoglobin to diagnose iron deficiency anemia using multiple methods. A total of 309 patients were included. The median age at diagnosis was 54 years. Most were females (71.2%). 68% had iron deficiency anemia. Patients with IDA had significantly lower levels of CHr compared to those who had non-IDA (p < 0.0001). The optimal cut-off value of CHr for detecting IDA, determined using various methods, was 30.15 pg. This cut-off point had a sensitivity of 87.8% and a specificity of 77.7%. CHr showed a significant positive correlation with hemoglobin, mean corpuscular volume, serum iron, serum ferritin, and transferrin saturation and a significant negative correlation with total iron-binding capacity. CHr levels correlate with most established laboratory tests for IDA. It reliably detects IDA. Our results indicate the importance of CHr in diagnosing IDA, and that CHr should be used more widely in suspected cases of IDA since it is a cheap, fast, and reliable test.

Adequacy of an Altitude Fitness Program (Living and Training) plus Intermittent Exposure to Hypoxia for Improving Hematological Biomarkers and Sports Performance of Elite Athletes: A Single-Blind Randomized Clinical Trial

Athletes incorporate altitude training programs into their conventional training to improve their performance. The purpose of this study was to determine the effects of an 8-week altitude training program that was supplemented with intermittent hypoxic training (IHE) on the blood biomarkers, sports performance, and safety profiles of elite athletes. In a single-blind randomized clinical trial that followed the CONSORT recommendations, 24 male athletes were randomized to an IHE group (HA, n = 12) or an intermittent normoxia group (NA, n = 12). The IHE consisted of 5-min cycles of hypoxia−normoxia with an FIO2 of between 10−13% for 90 min every day for 8 weeks. Hematological (red blood cells, hemoglobin, hematocrit, hematocrit, reticulated hemoglobin, reticulocytes, and erythropoietin), immunological (leukocytes, monocytes, and lymphocytes), and renal (urea, creatinine, glomerular filtrate, and total protein) biomarkers were assessed at the baseline (T1), day 28 (T2), and day 56 (T3). Sports performance was evaluated at T1 and T3 by measuring quadriceps strength and using three-time trials over the distances of 60, 400, and 1000 m on an athletics track. Statistically significant increases (p < 0.05) in erythropoietin, reticulocytes, hemoglobin, and reticulocyte hemoglobin were observed in the HA group at T3 with respect to T1 and the NA group. In addition, statistically significant improvements (p < 0.05) were achieved in all performance tests. No variations were observed in the immunological or renal biomarkers. The athletes who were living and training at 1065 m and were supplemented with IHE produced significant improvements in their hematological behavior and sports performance with optimal safety profiles.

Lower iron stores were associated with supoptimal gross motor scores in infants at 3-7 months

Aim

To investigate associations between iron status and gross motor scores in infants aged 3–7 months.

Methods

In a prospective study, 252 infants aged 3–7 months were examined using the age‐standardised Alberta Infant Motor Scale (AIMS) prior to analysing iron status in 250 infants. Combined AIMS and ferritin results were assessed in 226 infants, whereas AIMS and reticulocyte haemoglobin (ret‐Hb) results were obtained for 61 infants. We used logistic regressions and receiver operator characteristics to analyse our data.

Results

With AIMS z‐score <10th percentile as outcome measure, optimal cut‐off value for ferritin was 51 μg/L (sensitivity 86%, specificity 81%) and 28 pg for ret‐Hb (sensitivity 86%, specificity 85%). The area under the curve for ferritin and ret‐Hb was 0.886 and 0.896, respectively (n = 61). Ferritin <51 μg/L predicted an AIMS z‐score <10th percentile in a logistic regression (OR 3.3, 95% CI 1.4–7.5, p = 0.006, n = 226). Six of 14 (43%) infants with ret‐Hb <28 pg scored <10th percentile on AIMS compared to 1/47 (2.1%) infants with ret‐Hb ≥28 μg/L (Exact, p < 0.001).

Conclusion

Reticulocyte haemoglobin of <28 pg and ferritin <51 μg/L were associated with suboptimal gross motor scores in infants 3–7 months.

Combination of Hemoglobin-for-Age Z-Score and Plasma Hepcidin Identified as a Novel Predictor for Kawasaki Disease

Kawasaki disease (KD) is a febrile coronary vasculitis that affects younger children and includes complications such as coronary artery aneurysm. KD diagnoses are diagnosed based on clinical presentations, a process that still poses a challenge for front-line physicians. In the current study, we developed a novel predictor using the hemoglobin-for-age z-score (HbZ) and plasma hepcidin to differentiate Kawasaki disease (KD) from febrile children (FC). There were 104 FC and 115 KD subjects (89 typical KD; 26 incomplete KD) for this study, and data were collected on the biological parameters of hemoglobin and plasma hepcidin levels. A receiver operating characteristic curve (auROC), multiple logistics regression, and support vector machine analysis were all adopted to develop our prediction condition. We obtained both predictors, HbZ and plasma hepcidin, for distinguishing KD and FC. The auROC of the multivariate logistic regression of both parameters for FC and KD was 0.959 (95% confidence interval = 0.937–0.981), and the sensitivity and specificity were 85.2% and 95.9%, respectively. Furthermore, the auROC for FC and incomplete KD was 0.981, and the sensitivity and specificity were 92.3% and 95.2%, respectively. We further developed a model of support vector machine (SVM) classification with 83.3% sensitivity and 88.0% specificity in the training set, and the blind cohort performed well (78.4% sensitivity and 100% specificity). All data showed that sensitivity and specificity were 81.7% and 91.3%, respectively, by SVM. Overall, our findings demonstrate a novel predictor using a combination of HbZ and plasma hepcidin with a better discriminatory ability for differentiating from WBC and CRP between children with KD and other FC. Using this predictor can assist front-line physicians to recognize and then provide early treatment for KD.

The effect of reticulocyte hemoglobin content on the diagnosis of iron deficiency anemia: A meta-analysis study

Background

Iron deficiency anemia (IDA) is the most common type of anemia worldwide and has many adverse effects on life quality. This meta-analysis study aims to show that reticulocyte hemoglobin content (CHr) is more effective than routinely used parameters in the diagnosis of IDA.

Methods

Comprehensive and systematic research was done using international databases including PubMed, Web of Science, Cochrane Library, Science Direct, and Google Scholar, which contain all articles published on IDA until December 29, 2020. Seventeen articles were included in the meta-analysis.

Results

The analyses found the Cohen's deffect size (Standardized Mean Difference) values of the parameters. Accordingly, CHr is 2.84 (95% CI 2.36 to 3.31), mean corpus volume (MCV) is 2.46 (95% CI 1.97 to 2.95), ferritin is 2.37 (95% CI 1.63 to 3.11), and transferrin saturation (TSAT) is 3.76 (95% CI 2.14 to 5.38). To diagnose IDA, the sensitivity value of the CHr concentration was found as 83.5% (95% CI 76.1 to 89.8), specificity value to be 91.8% (95% CI 85.5 to 96.4), and mean cut-off value as 28.2 pg.

Conclusions

The results of our study reveal the findings that CHr is a better biomarker than MCV and ferritin used in determining IDA, and its efficacy is lower than TSAT. It is very important to use it routinely for the pre-diagnosis of IDA, which is very important for public health. The groups in the study are heterogeneous but contain bias. Therefore, meta-analyses of studies with less heterogeneity of CHr are needed.

Maternal diabetes and the role of neonatal reticulocyte hemoglobin content as a biomarker of iron status in the perinatal period

AIMS

We aimed to evaluate the effects of maternal diabetes on neonatal iron status, measuring erythrocyte indices including hemoglobin, hematocrit, reticulocytes, mean corpuscular volume (MCV), percent (%) hypochromia, ferritin, and additionally mean reticulocyte hemoglobin content (MCHr) as an early marker of iron deficiency, and examine the association between neonatal MCHr, red cell indices, and ferritin.

MATERIALS AND METHODS

We conducted a hospital-based prospective cohort study in a tertiary neonatal unit of a University Hospital from 2018 to 2020. We enrolled 126 maternal-infant pairs of mothers whose pregnancy was associated with diabetes and 74 maternal-infant pairs from uncomplicated pregnancies. Erythrocyte indices were analyzed within the first twelve hours after birth. Erythrocyte parameters were compared between infants of the diabetes and the non-diabetic group. We examined the correlation of the neonatal MCHr with perinatal characteristics, including gestation, birth weight, maternal body mass index, the erythrocytic indices, maternal diabetes, maternal obesity, prematurity, small-for-gestational-age status, maternal preeclampsia, and maternal anemia. Finally, we evaluated the discordance between neonatal MCHr and neonatal ferritin.

RESULTS

Infants of the diabetes group had a significantly lower MCHr (32.6 pg vs. 34.2 pg, p=0.003) compared with infants of uncomplicated pregnancies. Neonatal MCHr was significantly correlated with maternal hypochromia (r=-0.237, p=0.004) and neonatal MCV (r=0.674, p<0.001). Neonatal MCHr was significantly associated with maternal diabetes [standardized coefficients 0.21, 95% confidence interval (CI) 0.05-0.58, p=0.003) and maternal preeclampsia (standardized coefficients 0.17, 95% CI 0.02-0.92, p=0.019), after adjusting for maternal anemia, maternal obesity, prematurity, and small-for-gestational-age status. Those results were consistent also when analyzing maternal-infant pairs with pre-existing diabetes, and maternal-infant pairs with gestational diabetes. There was significant discordance between neonatal MCHr and neonatal ferritin (p=0.001).

CONCLUSIONS

MCHr was significantly lower in infants of mothers whose pregnancy was associated with diabetes compared with infants of non-diabetic mothers and correlated with neonatal and maternal red cell indices of iron deficiency. Since there was significant discordance between neonatal MCHr and ferritin during the first postnatal day, it is possible that MCHr could be used as a screening test for iron deficiency, especially in infants.

Bioymifi, a novel mimetic of TNF-related apoptosis-induced ligand (TRAIL), stimulates eryptosis

Tumor necrosis factor-related apoptosis-induced ligand (TRAIL) is a cytokine that initiates apoptosis upon binding to death receptor 5 (DR5) on cancer cells. Small molecule TRAIL mimetics have therefore been investigated as promising chemotherapeutic agents. Since anemia of chemotherapy is common, our goal is to investigate the hemolytic and eryptotic properties of novel DR5 agonist bioymifi (BMF) and identify the underlying molecular mechanisms. Whole blood (WB) was stimulated with 100 μM of BMF, whereas red blood cells (RBCs) were treated with 10-100 μM of BMF for 24 h at 37 °C. WB was analyzed for RBC, leukocyte, and platelet indices, while RBCs were examined for hemolysis by light absorbance of free hemoglobin, membrane scrambling by Annexin V-FITC, calcium by Fluo4/AM, cellular morphology by light scatter, and oxidative stress by 2',7'-dichlorodihydrofluorescein diacetate (H₂DCFDA) using flow cytometry. Caspase inhibitor Z-VAD-FMK, p38 inhibitor SB203580, casein kinase 1α inhibitor D4476, receptor-interacting protein 1 inhibitor necrostatin-2, reduced glutathione, or cyclooxygenase (COX) inhibitor aspirin were added accordingly. BMF exerted dose-responsive, calcium-independent hemolysis, reduced RBC hemoglobin, significantly increased Annexin V-, Fluo4-, and DCF-positive cells, along with a dual effect on forward and side light scatter. Notably, the cytotoxic potential of BMF was significantly mitigated upon pharmacological inhibition of p38. Furthermore, BMF exhibited selective toxicity to eosinophils and significantly diminished reticulocyte hemoglobin content. Altogether, these novel findings highlight the adverse outcomes of BMF exposure on RBC physiology and provide the first toxicological assessment of BMF as an antitumor agent.

Iron

Iron deficiency anemia affects approximately one-third of the world's population, and about half the cases are due to iron deficiency. The latest research on iron metabolism published in original articles and systematic reviews is described, and references to recent reviews provided. The topics include dietary sources and bioavailability, iron homeostasis, functions of iron in the body, and biomarkers of status. The consequences of iron deficiency and excess are discussed, with particular focus on vulnerable populations such as pregnant women, infants and the elderly. The newest dietary recommendations, including dietary reference values and food based dietary guidelines, are briefly summarized, followed by the latest developments in food fortification and iron supplementation.

The changing landscape of iron deficiency

Iron deficiency (ID) with or without anemia is common worldwide. ID is a broad definition encompassing decreased total body iron (absolute deficiency) as well as reduced iron supply to erythropoietic and/or other organs with preserved stores (functional iron deficiency, FID), as it occurs in inflammation. Increased iron needs unbalanced by iron supply, low iron intake, reduced absorption and chronic blood loss, often in combination, are the main causes of absolute ID, easily diagnosed by low ferritin levels. In all these cases hepcidin synthesis is repressed, while in FID is augmented by inflammatory cytokines, causing iron sequestration in stores. Because of increased ferritin levels diagnosis of ID in the latter condition may be tricky: global clinical evaluation, accepted threshold of iron tests together with response to iron treatment may be of help. Search and removal of the responsible cause(s) is as important as diagnosing ID or FID. The response to oral iron treatment is suboptimal when hepcidin levels are high. Future research is needed to establish/validate markers for improved diagnosis of complex cases and to test the therapeutic value of drugs under development aimed at interfering with the altered iron trafficking.