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.

Iron deficiency in sepsis patients based on reticulocyte hemoglobin and hepcidin concentration: a prospective cohort study

Introduction

Iron tests are deranged in sepsis; therefore new biomarkers should be used for diagnosis of iron deficiency (ID)/ID anemia (IDA).

Methods

Diagnosis of ID/IDA was based on reticulocyte (Ret) hemoglobin (Hb) equivalent (Ret-He) and Hb concentration, with hepcidin (Hep) determined retrospectively.

Results

The prevalence of ID and IDA was 7% and 47%, respectively. The AUROCs for Rets number and Hep in prediction of ID/IDA were 0.69 and 0.62, respectively.

Conclusions

Approximately half of sepsis patients are iron-deficient. Number of Rets may be a predictor of ID/IDA when Ret-He is not available. Hepcidin is a poor IDA predictor.

The association of hepcidin, reticulocyte hemoglobin equivalent and anemia-related indicators on anemia in chronic kidney disease

Hepcidin is an essential regulator of iron homeostasis in chronic kidney disease (CKD) anemia, reticulocyte hemoglobin equivalent (RET-He) can be used to evaluate the availability of iron for erythropoiesis. Previous research has found that hepcidin indirectly regulates RET-He. This study aimed to investigate the association of hepcidin, RET-He and anemia-related indicators on anemia in chronic kidney disease. A total of 230 individuals were recruited, including 40 CKD3-4 patients, 70 CKD5 patients without renal replacement therapy, 50 peritoneal dialysis patients, and 70 hemodialysis patients. The serum levels of hemoglobin (Hb), reticulocyte, RET-He, serum iron, serum creatinine, serum ferritin, total iron binding capacity, hepcidin-25, high sensitivity C-reactive protein, transferrin, erythropoietin, intrinsic factor antibody, soluble transferrin receptor and interleukins-6 (IL-6) were measured. Hepcidin-25 was positively associated with IL-6, and negatively with total iron binding capacity, intrinsic factor antibody, and transferrin. Reticulocyte Hb equivalent was associated positively with Hb, serum ferritin, serum iron, transferrin saturation, and negatively with serum creatinine, reticulocyte, IL-6, STfR. Hepcidin-25 was not associated with RET-He, while IL-6 was independently associated with hepcidin-25 and RET-He, suggesting that hepcidin has no effffect on the iron dynamics of reticulocytes in CKD, may be related to IL-6, indicate a likelihood of a threshold for stimulation of hepcidin-25 expression by IL-6 in order to indirectly regulates RET-He.

Reticulocyte Hemoglobin Equivalent has Comparable Predictive Accuracy as Conventional Serum Iron Indices for Predicting Iron Deficiency and Anemia in a Nonhuman Primate model of Infantile Iron Deficiency

BACKGROUND

Infantile iron deficiency (ID) causes anemia and compromises neurodevelopment. Current screening relies on hemoglobin (Hgb) determination at 1 year of age, which lacks sensitivity and specificity for timely detection of infantile ID. Low reticulocyte Hgb equivalent (RET-He) indicates ID, but its predictive accuracy relative to conventional serum iron indices is unknown.

OBJECTIVES

The objective was to compare diagnostic accuracies of iron indices, red blood cell (RBC) indices, and RET-He for predicting the risk of ID and IDA in a nonhuman primate model of infantile ID.

METHODS

Serum iron, total iron binding capacity, unsaturated iron binding capacity, transferrin saturation (TSAT), Hgb, RET-He, and other RBC indices were determined at 2 wk and 2, 4, and 6 mo in breastfed male and female rhesus infants (N = 54). The diagnostic accuracies of RET-He, iron, and RBC indices for predicting the development of ID (TSAT < 20%) and IDA (Hgb < 10 g/dL + TSAT < 20%) were determined using t tests, area under the receiver operating characteristic curve (AUC) analysis, and multiple regression models.

RESULTS

Twenty-three (42.6%) infants developed ID and 16 (29.6%) progressed to IDA. All 4 iron indices and RET-He, but not Hgb or RBC indices, predicted future risk of ID and IDA (P < 0.001). The predictive accuracy of RET-He (AUC = 0.78, SE = 0.07; P = 0.003) for IDA was comparable to that of the iron indices (AUC = 0.77-0.83, SE = 0.07; P ≤ 0.002). A RET-He threshold of 25.5 pg strongly correlated with TSAT < 20% and correctly predicted IDA in 10 of 16 infants (sensitivity: 62.5%) and falsely predicted possibility of IDA in only 4 of 38 unaffected infants (specificity: 89.5%).

CONCLUSIONS

RET-He is a biomarker of impending ID/IDA in rhesus infants and can be used as a hematological parameter to screen for infantile ID.

Reticulocyte Hemoglobin-Equivalent Potentially Detects, Diagnoses and Discriminates between Stages of Iron Deficiency with High Sensitivity and Specificity

Background: Iron deficiency anemia (IDA) is a global health problem affecting the quality of life of more than 2 billion individuals. The current practice guidelines diagnose and monitor IDA via conventional hematological and iron biomarkers, which take several months before they are corrected under an iron-treatment plan. Reticulocyte hemoglobin equivalent (Ret-He) is used as a marker in most new hematology analyzers to assess iron incorporation into erythrocyte hemoglobin directly. This study aims to examine the efficacy of Ret-He as a marker for iron deficiency (ID) and IDA and investigate whether Ret-He is sensitive to iron therapy. Methods: Two blood samples were drawn from 182 participants for CBC and iron profile measurements. Follow-up samples were drawn from participants with a confirmed diagnosis of ID and/or IDA. Results: Ret-He levels were lower in the ID and IDA groups compared to the control (p < 0.0001), and lower in the IDA group compared to the ID group (p < 0.0001). Ret-He was correlated with ferritin at ID level (<30.0 mg/mL; r = 0.39) and severe IDA (<13.0 ng/mL; p-value < 0.01, r = 0.57). Cut-off values of <28.25 pg for ID and <21.55 pg for IDA showed a higher specificity and sensitivity (ID; AUC: 0.99, sensitivity: 92.73%, specificity: 97.87%) and (IDA; AUC: 0.94, sensitivity: 90.63%, specificity: 92.31%). Finally, Ret-He successfully reflected the iron therapy (p < 0.001) when compared to hemoglobin (Hb) (p = 0.1). Conclusions: Ret-He is a potential marker for detecting and diagnosing different stages of ID with high validity and is very sensitive in reflecting the iron incorporation in a short time.

The Reticulocyte Hemoglobin Equivalent as a Screening Marker for Iron Deficiency and Iron Deficiency Anemia in Children

Background: Iron deficiency (ID) is one of the most common nutritional deficiencies in children worldwide and may result in iron deficiency anemia (IDA). The reticulocyte hemoglobin equivalent (Ret-He) provides information about the current availability of iron in erythropoiesis. This study aims to examine the validation of Ret-He as a screening marker for ID and IDA in children. Methods: Blood samples were retrospectively obtained from medical records. Anemia was defined according to the definition provided by the World Health Organization (WHO) for children. ID was defined by transferrin saturation (TSAT) < 20% and ferritin < 100 ng/mL. Children were classified into four groups: IDA, non-anemia iron deficiency (NAID), control and others. Results: Out of 970 children, 332 (34.2%) had NAID and 278 (28.7%) presented with IDA. Analysis revealed that Ret-He significantly correlates with ferritin (rho = 0.41; p < 0.001), TSAT (rho = 0.66; p < 0.001) and soluble transferrin receptor (sTfR) (rho = −0.72; p < 0.001). For ROC analysis, the area under the curve (AUC) was 0.771 for Ret-He detecting ID and 0.845 for detecting IDA. The cut-off value for Ret-He to diagnose ID was 33.5 pg (sensitivity 90.7%; specificity 35.8%) and 31.6 pg (sensitivity 90.6%; specificity 50.4%) to diagnose IDA. Conclusions: The present study demonstrates Ret-He to be a screening marker for ID and IDA in children. Furthermore, Ret-He can be used as a single screening parameter for ID and IDA in children without considering other iron parameters. Economically, the use of Ret-He is highly relevant, as it can save one blood tube per patient and additional costs.

Reticulocyte Hemoglobin Equivalent in Patients with Idiopathic Warm Autoimmune Hemolytic Anemia: Implication in the Development of Macrocytosis

OBJECTIVE

Patients with warm autoimmune hemolytic anemia (WAIHA) present with anemia that is highly heterogeneous, and often have macrocytic anemia with inappropriately elevated mean corpuscular volume (MCV). The goal of this retrospectivecase study is to elucidate the characteristics of anemia in patients with idiopathic WAIHA.

PROCEDURES

The hematological parameters were analyzed by automated hematology analyzers in 19 consecutive patients with idiopathic WAIHA. Thecontent of hemoglobin (Hb) in the reticulocytes was assessed as reticulocyte Hb equivalent (RET-He). Relevant laboratory data and medical records were retrospectively studied.

RESULTS

The median MCV was 102.7 fL and ten patients had macrocytic anemia with MCV above 100 fL. There was a significant correlation between the percentage of reticulocytes and MCV. The median RET-He value was 35.9 pg, and the reticulocytes of patients with higher MCV had higher RET-He. There was a significant correlation between red cell volume distribution width (RDW) andMCV, while the association between RDW and RET-He was not significant. Red blood cell agglutination was not seen in any of the patients. Relative folate deficiency was implied to contribute to the increased Hb content in the reticulocytes of WAIHA patients.

CONCLUSION

Reticulocytes in WAIHA patients often contain more Hb than normal reticulocytes and become inappropriately large, possibly due to relative folate deficiency. Elevated MCV in WAIHA patients is due to the increase in both the number and the Hb content of reticulocytes.

Clinical usefulness of the reticulocyte hemoglobin equivalent in children on hemodialysis

INTRODUCTION

Iron-deficiency anemia is common in hemodialysis patients. Serum ferritin and transferrin saturation (TS) are used for its detection. The reticulocyte hemoglobin equivalent (RET-He) is a marker that is not altered by inflammatory conditions and directly reflects iron availability in the bone marrow.

OBJECTIVE

To explore the diagnostic capability of RET-He to detect absolute iron deficiency and assess its correlation with traditional markers of iron deficiency.

POPULATION AND METHODS

Retrospective study comparing RET-He with ferritin and TS in children on hemodialysis seen at Hospital Garrahan between July 2016 and July 2019.

RESULTS

In 164 observations carried out in 40 children, a weak positive correlation was found between hemoglobin and RETHe (r = 0.35, p < 0.001), a significant positive correlation between TS and RET-He (r = 0.52, p < 0.001), a low negative correlation between hemoglobin and ferritin (r = -0.19, p = 0.02), and a lack of correlation between hemoglobin and TS (r = 0.05, p = 0.5). Anemia was observed in 50 %; iron-deficiency anemia was detected by traditional markers in 13 % and by RET-He in 44 %. RET-He showed a sensitivity of 90.9 % (95 % CI: 57.1-99.5 %), a specificity of 74.5 % (95 % CI: 66.7-81 %), a negative predictive value of 99.1 % (95 % CI: 94.5-99.9 %), and a positive predictive value of 20.4 % (95 % CI: 10.7-34.7 %) to detect iron-deficiency anemia with a cut-off value of 29 pg.

CONCLUSIONS

Despite its limited capability, the use of RET-He as a biomarker of iron deficiency increases the detection of iron-deficiency anemia in children on hemodialysis.

Reticulocyte hemoglobin equivalent in a thalassemia-prevalent area

BACKGROUND

Reticulocyte hemoglobin equivalent (Ret-He), a direct measure of the hemoglobin (Hb) in the young red blood cells, has been reported to be useful in the diagnosis of iron deficiency anemia (IDA) but may have some limitations in thalassemia trait. This study evaluated the differences in Ret-He in school-aged children, and assessed the diagnostic value of Ret-He in identifying IDA in a thalassemia-prevalent area.

METHODS

Blood samples underwent complete blood count analysis, including Ret-He, ferritin, serum iron and total iron binding capacity. Blood samples also underwent Hb typing and a molecular study for α-thalassemia. Receiver operating characteristic analysis was performed to determine the predictive capacity of Ret-He in the diagnosis of IDA. ID was defined as serum ferritin <30 ng/mL and/or transferrin saturation (TSAT) <16%; IDA was defined as serum ferritin <12 ng/mL and/or TSAT <16% with low Hb for age. Normal healthy children (normal controls: NC) had normal iron study, without the thalassemia trait.

RESULTS

Ninety-eight children with a mean age of 12.9 ± 0.6 years were included. Ret-He in the thalassemia trait group (26.7 ± 2.4 pg), ID group (29.0 ± 2.9 pg), IDA group (25.4 ± 2.7 pg), ID + thalassemia trait group (26.6 ± 2.8 pg), and the IDA + thalassemia trait group (24.6 ± 2.3 pg) was significantly lower than in the NC group (30.8 ± 1.7 pg; P < 0.001, 0.01, 0.006, 0.002 and <0.001, respectively). Ret-He had an area under the curve of 0.904 in diagnostic ability for IDA, while a cut-off ≤27 pg had a sensitivity of 91.7% and a specificity of 81%.

CONCLUSION

Ret-He was lowest in subjects with IDA + thalassemia trait. A Ret-He cut-off ≤27 pg was suggestive of IDA in the present study.