The usefulness of soluble transferrin receptor in the diagnosis and treatment of iron deficiency anemia in children

Iron Status of Preadolescents Without Clinical Pallor Attending a Tertiary Care Hospital in South India- A Cross-Sectional Analytical Study

OBJECTIVES

To determine the prevalence of Iron Deficiency (ID) in children without clinical pallor using serum ferritin and the new parameters, soluble transferrin receptor (sTfR) & the ratio of sTfR/log10 serum ferritin (sTfR-F index), as suggested by WHO. Also to assess whether these new parameters could individually predict the presence of ID.

METHODS

Consecutive 230 healthy children aged 9-11 y without clinical pallor underwent estimation of Hemoglobin (Hb), C-Reactive Protein (CRP), serum ferritin, sTfR, and sTfR-F index levels in their blood. The abilities of the sTfR and sTfR-F index in predicting ID were determined by comparing with the gold standard (normal CRP and less serum ferritin), plotting Receiver-operating characteristic (ROC) curve, and noting the area under the curve (AUC).

RESULTS

The blood reports of 114 boys and 106 girls (total = 220) were available for analysis. Overall, 57 (31 girls, 26 boys) children had ID; among children with low CRP, 45 had ID, as suggested by low serum ferritin levels. Among children with high CRP, 12 had evidence of ID as evidenced by elevated sTfR and/or sTfR-F index. The positive predictive values of both sTfR and sTfR-F were low (32.9% and 35.9%, respectively) than the negative predictive values (85.6% and 95.3%, respectively).

CONCLUSIONS

The proportion of children identified to have ID using serum ferritin, sTfR, and sTfR-index was 25.9%. sTfR and/or sTfR-F index are unlikely to be ideal individual predictors of ID.

Anaemia of chronic disease among pulmonary tuberculosis patients is associated with inflammatory marker at the start of intensive phase

Background

Tuberculosis (TB) disrupts iron balance through systemic inflammation. Pulmonary tuberculosis (PTB) is linked to diverse anaemia types, necessitating intricate haematological and biochemical assessments for diagnosis. This study aims to describe the prevalence of anaemia of chronic disease (ACD), iron deficiency anaemia (IDA) among PTB patients and factors associated with these types of anaemia.

Methods

A cross-sectional analysis was conducted from community-based cohort study involving sputum-positive PTB patients from 2018 to 2020 in urban Puducherry. Participants were enrolled from 10 primary health centres within 2 weeks of initiating anti-tubercular treatment (ATT). Blood samples were collected for assessing haematological and biochemical parameters. The sTfR/log ferritin ratio was used to distinguish between ACD and IDA. Data were captured using Epicollect5 and analysed using STATA V14.

Result

Of the 176 PTB patients included, 63.07% (111/176) had anaemia, with ACD being the predominant type (84.6%, 94/111). The C-reactive protein (CRP) levels were higher among the anaemic group [40.77 (16.66-58.51) mg/dl vs 24.65 (14.23-47.26) mg/dl] and higher among the ACD as compared to IDA [46.9 (22.3-61.2) vs 20.8 (13.0-39.1) mg/dl]. Undernourished [adjusted prevalence ratio (APR) =3.43; confidence interval (CI): 1.21-9.69] and patients having low risk of dependence on tobacco [APR = 1.52; CI: 1.10-2.11] had higher risk of ACD. Female patients had higher risk of IDA [APR = 4.95, P < 0.01].

Conclusion

The largest proportion of the PTB participants with anaemia had ACD. Acute-phase reactant and inflammatory marker are increased among newly diagnosed new sputum smear-positive (NSP) PTB participants at the start of ATT. Addressing inflammation is needed for combating anaemia in PTB patients.

Formulation and Effect of Iron Fortified Instant Bose Corn on Addressing Anemia among Adolescent Girls in Kupang, Indonesia

This study aimed to develop Fe-fortified instant Bose corn (IBC), a traditional Timorese food, as a strategy to address anemia among adolescent girls in Kupang, Indonesia. Instant corn and cowpea grits were made to shorten the preparation time with various times of soaking (IBC1=10 min; IBC2=15 min; IBC3=20 min) to select the best formula. The selected IBC was then fortified with NaFeEDTA·3H₂O and nutrient content was evaluated. In the intervention study, a pre-post controlled trial was applied to 40 anemic adolescent girls aged 16∼19 years. Subjects with severe anemia (Hb=8.5∼10.4 g/dL) received the fortified selected IBC, whereas those with moderate anemia (Hb=10.5∼11.5 g/dL) received the unfortified selected IBC. A total of 100 g IBC were provided three times/week for 2 months. The hemoglobin and soluble transferrin receptor (sTfR) levels were measured at baseline and endline, respectively. IBC3 produced the highest acceptance level as compared to other formulas. The fortified IBC3 met 127.4% recommended dietary allowances for iron. Moreover, both fortified and unfortified IBC3 significantly increased the hemoglobin levels of adolescent girls with the higher improvement found in the group of fortified IBC3 (1.73±1.21 g/dL; P<0.05). However, the beneficial effects of the fortified IBC3 could not be observed on sTfR levels. Since the effect on Hb levels was significant with less effect, the intervention of IBC3 for only 2 months did not adequate to improve sTfR levels. Nevertheless, this study suggests that Fe-fortified IBC may be effective in preventing anemia among adolescent girls in Kupang, Indonesia.

Prevalence of anemia in pre-school tribal children with reference to parasitic infections and nutritional impact

Objectives

Anemia is a global health problem and has very high prevalence in developing as well as developed countries, particularly in children and women. The present study evaluates hematological predictors, nutrition deficiency, parasitic infections and their association with the prevalence of anemia. This analysis will help to identify the anemic status of tribal preschool children.

Methods

This was a cross-sectional study conducted in 300 children (age: 6 months to 5 years) in Santrampur village, Gujarat. Blood was collected and used to determine complete blood count (CBC); we also performed ELISA (enzyme-linked immunoassay) for the estimation of ferritin, transferrin, sTfR (soluble transferrin receptor), vitamin B₁₂ and vitamin B₉ (folate). Stool samples were also collected and assessed by ELISA for Entamoeba histolytica, Giardia lamblia and Cryptosporidium parvum. Microscopy was used to screen samples for malaria.

Results

Of the 300 children analyzed, 87.7% were anemic, 239 children were mildly anemic, 20 were moderately anemic and 4 were severely anemic. Mean Hb level was 9.49 ± 1.47 g/dL; males and females had an Hb level of 9.39 ± 1.59 g/dL and 9.58 ± 1.34 g/dL, respectively. Twenty-six children had sickle cell anemia and five had thalassemia. Over 50% of the children had vitamin B₁₂ and B₉ deficiency and 16% had abnormalities in CRP (C-reactive protein) levels. Parasitic infection by C. parvum was positively associated the anemia followed by the prevalence of G. lamblia and E. histolytica.

Conclusion

An increased awareness of parents in the improvement of sanitary facilities and nutritional counselling with regards to iron-rich food consumption is recommended to if we are to prevent anemia among pre-school children. To reduce parasitic infestation, effective periodic deworming measures are also recommended

Malnutrition, anemia, micronutrient deficiency and parasitic infections among schoolchildren in rural Tanzania

Background

Malnutrition, anemia, micronutrient deficiency and parasitic infections continue to impact the nutritional status and health of children in lower-income countries. However, not enough data concerning this issue is available. The aim of this study was to assess the distribution of nutritional indicators, anemia and micronutrient deficiency and their underlying risk factors among schoolchildren in south-eastern Tanzania.

Methodology/Principal findings

This cross-sectional study enrolled primary schoolchildren aged 6–12 years from Kikwawila and Kiberege wards, Tanzania. In total, 471 schoolchildren underwent a physical examination and provided blood, stool and urine samples for an assessment of the levels of different micronutrients, nutritional and anemia status, and parasitic infection status. We employed bivariate and multivariate logistic regression to determine the association between nutritional statuses, anemia, micronutrient deficiency and parasitic infections. We found that 23.90%, 12.60% and 16.20% of schoolchildren were stunted, underweight and wasted, respectively. About 14.0% of schoolchildren were found to be anemic. Children diagnosed with Plasmodium falciparum infection were more likely to have low levels of ferritin (aOR: 10.40, 95% CI: 2.88-40.53) and elevated levels of serum soluble transferrin receptor (aOR: 3.59, 95% CI: 1.27-11.23), respectively. Vitamin A (34.71%) and vitamin B12 (8.79%) were the most prevalent micronutrients found to be deficient in diagnosed children. Finally, we found that schoolchildren attending the most rural schools were five times more likely to be diagnosed with at least one micronutrient deficiency (aOR: 5.04, 95% CI: 2.38–11.44).

Conclusions/Significance

Malnutrition, anemia and micronutrient deficiency still pose a significant health burden among schoolchildren living in rural Tanzania. To effectively tackle this burden, health interventions such as deworming, micronutrient supplementation, vector control, health education and access to clean water and improved sanitation should be strengthened and made sustainable.

In this study, we assessed the distribution and risk factors of nutritional indicators, anemia and micronutrient deficiency among schoolchildren of the Kikwawila and Kiberege wards, Tanzania. Our analysis revealed that malnutrition in form of stunting and wasting is still very high among schoolchildren in this region. About 14.0% of children were found to be anemic. Micronutrient deficiency was highly variable ranging from 0.50% (Folate) to 35.0% (Vitamin A). Schoolchildren from most rural schools were more likely to be found stunted and deficient with at least one type of micronutrient. Efforts to control and eliminate malnutrition, anemia, micronutrient deficiency and parasitic infections would benefit from sustainable and integrated approaches such as deworming, micronutrient supplementation, health education, vector control and an improvement in access to clean water and improved sanitation.

Iron deficiency in proteinuric children with nephrotic syndrome: A cross-sectional pilot study

Massive proteinuria in nephrotic syndrome causes depletion of various proteins. Iron deficiency can occur due to urinary loss of iron, transferrin, and soluble transferrin receptors. We conducted this cross-sectional study of 52 children with proteinuric nephrotic syndrome, aged 1-12 years (mean 7.1±2.7 years). Hemoglobin (Hb), RBC indices (MCV, MCH, MCHC), percentage of hypochromic RBCs (Hypo-He), reticulocyte hemoglobin content (Ret-He), and serum ferritin were examined. Seven (13%) patients had iron deficiency anemia and another 10 (19%) exhibited iron deficiency. A higher proportion of children with steroid-resistant disease had anemia than did steroid-sensitive children (P=0.076). Thus, children with nephrotic syndrome may have iron deficiency (32.7%), which needs to be screened.

Rapid diagnostics for point-of-care quantification of soluble transferrin receptor

BACKGROUND

Iron deficiency (ID) and anaemia are major health concerns, particularly in young children. Screening for ID based on haemoglobin (Hb) concentration alone has been shown to lack sensitivity and specificity. The American Academy of Pediatrics (AAP) recommends soluble transferrin receptor (sTfR) as a promising approach to screen for iron deficiency. However, in most settings, assessment of iron status requires access to centralized laboratories. There is an urgent need for rapid, sensitive, and affordable diagnostics for sTfR at the point-of-care.

METHODS

An immunochromatographic assay-based point-of-care screening device was developed for rapid quantification of sTfR from a drop of serum within a few minutes. Performance optimization of the assay was done in sTfR-spiked buffer and commercially available sTfR calibrator, followed by a small-scale proof-of-concept validation with archived serum samples.

FINDINGS

On preliminary testing with archived serum samples and comparison with Ramco ELISA, a correlation of 0.93 (P < 0.0001) was observed, demonstrating its potential for point-of-care assessment of iron status.

INTERPRETATION

The analytical performance of the point-of-care sTfR screening device indicates the potential for application in home-use test kits and field settings, especially in low- and middle-income settings. An added advantage of sTfR quantification in combination with our previously reported serum ferritin diagnostics is in integration of Cook's equation as a quantitative and minimally-invasive indicator of total body iron stores. FUND: Thrasher Research Fund (Early Career Award #13379), NIH R03 EB 023190, NSF grant #1343058, and Nutrition International (project #10-8007-CORNE-01).

Soluble transferrin receptor as a marker of erythropoiesis in patients undergoing high-flux hemodialysis

Anemia is a common complication in chronic kidney disease (CKD) patients receiving hemodialysis. The effect of high-flux dialysis (HFD) on anemia remains unclear. This prospective study aimed to evaluate the effect of HFD on anemia, and the potential of soluble transferrin receptor (sTfR) as a marker of iron status and erythropoiesis in CKD patients on hemodialysis. Forty patients, who switched from conventional low-flux dialysis to HFD for 12 months, were enrolled in this study. The levels of sTfR, hemoglobin (Hb), iron, and nutritional markers, as well as the dose of recombinant human erythropoietin (rhEPO) and use of chalybeate were determined at 0, 2, 6, and 12 months after starting HFD. HFD significantly increased the hemoglobin level and reduced sTfR level in CKD patients (p < 0.05). In addition, significant decreasing linear trends were observed for rhEPO dosage and chalybeate use (p < 0.05). The level of sTfR was positively correlated with the percentage of reticulocytes (RET%), rhEPO dose, and chalybeate use, while it was negatively correlated with Hb levels and total iron-binding capacity results (all p < 0.05). A univariate generalized estimating equation (GEE) model showed that the Hb level, RET%, rhEPO dose, and chalybeate use were the variables associated with sTfR levels. A multivariate GEE model showed that the time points when hemodialysis was performed were the variables associated significantly with sTfR levels. Overall, our findings suggest that HFD can effectively improve renal anemia in hemodialysis patients, and sTfR could be used as a marker of erythropoiesis in HFD patients.

Anemia in nephrotic syndrome: approach to evaluation and treatment

Nephrotic syndrome is one of the most common glomerular diseases that affect in children. Complications may occur in nephrotic syndrome as a result of the disease itself as well as its treatment. Most of these complications result from excessive urinary protein losses, and control of proteinuria is the most effective treatment strategy. Anemia is one of the many complications seen in patients with persistent nephrotic syndrome and may occur as a result of excessive urinary losses of iron, transferrin, erythropoietin, transcobalamin and/or metals. This leads to a deficiency of substrates necessary for effective erythropoiesis, requiring supplementation in order to correct the anemia. Supplementation of iron and erythropoietin alone often does not lead to correction of the anemia, suggesting other possible mechanisms which need further investigation. A clear understanding of the pathophysiologic mechanisms of anemia in nephrotic syndrome is necessary to guide appropriate therapy, but only limited evidence is currently available on the precise etiologic mechanisms of anemia in nephrotic syndrome. In this review we focus on the current state of knowledge on the pathogenesis of anemia in nephrotic syndrome.

Value of Soluble Transferrin Receptors and sTfR/log Ferritin in the Diagnosis of Iron Deficiency Accompanied by Acute Infection

There are many causes of anemia; the most common of these are acute and chronic infections, iron deficiency, or both. Identifying the cause is a very important step in management of anemia. So, we evaluated the usefulness of soluble transferrin receptor (sTfR) and of the sTfR/log ferritin in the diagnosis of iron deficiency anemia accompanied by acute infection. This study was conducted on 131 children aged 2-11 years old from those who attended the pediatric outpatient clinics in Menoufia university hospital. Hematological indices, iron balance and sTfR were evaluated and the sTfR/log F was calculated for each examined child. From the examined children four groups were distinguished: Group I (control): included 34 healthy children with normal iron status (66.7% males, age 4.2 ± 1.2). Group II (IDA): included 38 children diagnosed as iron deficiency anemia (47.4% males, age 4.9 ± 1.6). Group III (IDA + infection): included 26 children with infectious disease (upper respiratory tract infection, otitis media, pneumonia, stomatitis, and urinary tract infection) and anemia meeting criteria of IDA (50% males, age 4.2 ± 0.7). Group IV (anemia + infection): included 33 children with infectious anemia without iron deficiency (56.2% males, age 5.06 ± 1.4). It was proved that sTfR and sTfR/log Ferritin were significantly higher in children with anemia due to iron deficiency, and in those with infection + iron deficiency, versus those with infectious anemia or in healthy children. The use of sTfR and sTfR/log ferritin improves the diagnosis of IDA in pediatric patients, especially in the presence of coexisting acute infection.

Using Soluble Transferrin Receptor and Taking Inflammation into Account When Defining Serum Ferritin Cutoffs Improved the Diagnosis of Iron Deficiency in a Group of Canadian Preschool Inuit Children from Nunavik

The prevalence of iron depletion, iron deficient erythropoiesis (IDE), and iron deficiency anemia (IDA) was assessed in preschool Inuit children using soluble transferrin receptor (sTfR) and traditional indicators of iron status while disregarding or taking inflammation into account when defining SF cutoffs. Iron depletion was defined as follows: (1) SF < 15 μg/L regardless of the C-reactive protein (CRP) level and (2) SF < 15 or <50 μg/L with CRP ≤ 5 or >5 mg/L, respectively. IDE corresponded to iron depletion combined with total iron binding capacity > 72 μmol/L and/or transferrin saturation < 16%. Iron depletion and IDE affected almost half of the children when accounting for inflammation, compared to one-third when the SF cutoff was defined regardless of CRP level (P < 0.0001). The prevalence of IDE adjusted for inflammation (45.1%) was very similar to the prevalence observed when sTfR was used as a sole marker of IDE (47.4%). The prevalence of anemia was 15%. The prevalence of IDA (IDE + hemoglobin < 110 g/L) was higher when accounting for than when disregarding inflammation (8.0% versus 6.2%, P = 0.083). Using sTfR and different SF cutoffs for children with versus without inflammation improved the diagnosis of iron depletion and IDE. Our results confirm that Inuit children are at particularly high risk for iron deficiency.

Optical sensor: a promising strategy for environmental and biomedical monitoring of ionic species

In this review, we cover the recent developments in fluorogenic and chromogenic sensors for Cu²⁺, Fe²⁺/Fe³⁺, Zn²⁺and Hg²⁺.