Immature Reticulocyte Fraction Research Articles

Reference range of complete blood count, Ret-He, immature reticulocyte fraction, reticulocyte production index in healthy babies aged 1–4 months

Establishing reference ranges of the complete blood count (CBC), reticulocyte hemoglobin content (Ret-He), immature reticulocyte fraction (IRF), and reticulocyte production index (RPI) helps diagnose a disease related to the changes in erythrocyte indices, white blood count, platelets, and reticulocytes, especially in babies. Therefore, the study aims to establish a reference range for CBC and reticulocyte parameters in healthy babies aged 1–4 months. The study design was a cross-sectional study with descriptive analysis of CBC and reticulocyte in babies aged 1–4 months. Three hundred forty-eight babies met the inclusion criteria. This study recruited 89 babies aged 1 month, 87 babies aged 2 months, 86 babies aged 3 months, and 86 babies aged 4 months. The P5-P95 reference range of healthy babies for hemoglobin (Hb) aged 1 month, 2 months, 3 months, and 4 months was 9.95 to 15.45 g/dL, 9.74 to 13.42 g/dL, 9.51 to 12.40 g/dL, and 10.04 to 13.10 g/dL respectively. The P3-P97 reference range of healthy babies for Hb aged 1 month, 2 months, 3 months, and 4 months was 9.60 to 15.90 g/dL, 9.46 to 13.97 g/dL, 9.26 to 12.82 g/dL, and 10.00 to 13.33 g/dL respectively. This study also defined reference ranges for CBC, Ret-He, IRF, and RPI. The reference range of CBC, Ret-He, IRF, and RPI for healthy babies aged 1–4 months in this study can be used as a benchmark.

Clinical significance of immature reticulocyte fraction (IRF) and reticulocyte maturity indices in differential diagnosis of anemia

Background: Anemia is most common public health problems in developing countries. It is important to know the cause of anemia to treat the patients. The Immature reticulocyte fraction (IRF) value is an early marker for evaluating the regeneration of erythropoiesis. In addition to conventional reticulocyte measurement, the fluorescence method allows the classification of reticulocytes into three maturation stages – LFR, MFR and HFR. Aims: To determine clinical significance of immature reticulocyte fraction (IRF) and reticulocyte maturity indices (LFR, MFR, HFR) in differential diagnosis of anemic patients. Material and Method: IRF and other reticulocyte parameters were measured by automated blood cell analyzer, Horiba Pentra XLR using fluorescence marker that labels RNA and DNA (such as thiazole orange or polymethines), in 124 patients with anemia. The anemia group consist of 50 iron deficiency anemia (IDA) patients, 29 cases of thalassemia trait patients and 45 patients with anemia due to chromic kidney diseases (CKD). In this retrospective and prospective type study, the values of IRF and other parameters were analysed and compared in each group for the duration of one year. Result: Total of 124 cases were evaluated with median age of age of 32.8 years showed that mean value of IRF was low in IDA (0.096±0.058) and in CKD (0.092±0.111) compare to thalassemia (0.116±0.094). The mean values of MFR and HFR were also found to be significantly lower in IDA group and in CKD when compared to the thalassemic group. Values of LFR were higher in IDA and in CKD compare to thalassemia. Conclusions: IRF assesses reticulocyte maturation by the intensity of the staining that reflects the mRNA content. The evaluation of IRF and reticulocyte maturity indices by automated cell counter analyzer seemed to be accurate and clinically useful for the early diagnosis of anemia and the differentiation of IDA and CKD from thalassemia.

Novel markers in predicting Brucella sacroiliitis: The platelet large cell ratio and basal immature reticulocyte fraction

Objective: To present platelet large cell ratio (P-LCR), reticulocyte, and immature reticulocyte fraction (IRF) values as novel parameters in diagnosis and response to treatment in patients developing sacroiliitis. Methods: Sixty-eight patients with clinical symptoms and Brucella standard tube agglutination (Wright) or Brucella Coombs agglutination test titers ≥1:160 were included in the study. Two groups were established, one developing sacroiliitis and another with no sacroiliitis development. P-LCR, reticulocyte, and IRF levels were measured using a Sysmex XN-9000 device (Japan). These were then compared between the two groups. Results: Reticulocyte (P=0.037) and IRF (P=0.026) levels were significantly lower among the patients developing sacroiliitis compared to the non-sacroiliitis group, while P-LCR (P=0.003) levels were significantly higher. P-LCR had the most powerful correlation with sacroiliitis development. Significant negative correlation was observed between reticulocyte, IRF levels and sacroiliitis. Conclusions: Elevated P-LCR levels were observed as a marker of persisting inflammation in patients developing sacroiliitis, while low reticulocyte and IRF levels secondary to bone marrow involvement were detected. These three parameters emerged as highly significant markers in terms of diagnosis and reflecting responses to treatment in organ involvement such as sacroiliitis in brucellosis. These are presented as inexpensive, and easily accessible novel parameters.

The effects of iron injection on blood doping biomarkers in dried blood spots.

Iron supplementation is not considered as a doping method; however, it can affect the levels of several biomarkers of the hematologic module of the athlete biological passport (ABP), such as the reticulocyte percentage (%RET) and hemoglobin (HGB) level. Thus, iron injection could be a confounding factor in antidoping analyses. Previous studies have suggested that the HGB level and the expression levels of reticulocyte-related-mRNAs, such as 5'-aminolevulinate synthase 2 (ALAS2) and carbonic anhydrase 1 (CA1), could be promising biomarkers for the ABP and detectable in dried blood spots (DBSs). Therefore, in this study, we examined the impact of iron injection on the levels of these potential biomarkers in DBSs. Reticulocyte-related-mRNAs analyses were performed by RT-qPCR. Ferritin level in DBS was measured with enzyme-linked immunosorbent assay(ELISA) method. Notably, there were no significant effects of iron supplementation on the levels of ALAS2 and CA1 mRNAs but by contrast, the %RET and immature reticulocyte fraction (IRF) measured in whole blood increased significantly following iron injection. As expected, iron supplementation increased the ferritin level significantly in both serum and DBS samples. In conclusion, these findings reinforce the specificity of reticulocyte-related mRNAs in DBSs as biomarkers of blood doping to target in antidoping analyses.

Prevalence of Iron Deficiency Anemia and Reference Range of Complete Blood Count, Reticulocyte Parameters in Infants Aged 9-11 Months.

Iron deficiency anemia (IDA) is still a major global health problem. Determination of reference ranges for complete blood count (CBC), reticulocyte hemoglobin content (Ret-He), immature reticulocyte fraction (IRF), and reticulocyte production index (RPI) are essential to help diagnose a disease. The study aims to know the prevalence of IDA, risk factors that influence it, and set a reference range for CBC and reticulocyte parameters in infants aged 9-11 months in Indonesia. The study was conducted prospectively at 10 Community Health Centers in Banjarbaru, South Kalimantan, Indonesia, from August 2020 to August 2021. This study recruited 100 healthy infants (47% boys, 53% girls) aged 9-11 months. The prevalence of IDA was 32%. There is no association between IDA prevalence with the mother's education and occupation, maternal parity, family income, and infant nutritional status (p > 0.05). The reference range for hemoglobin (Hb) at P2.5-P97.5, P3-P97, P5-P95 and mean ± 2SD was 11.06 to 14.34 g/dL, 11.10 to 14.31 g/dL, 11.13 to 13.90 g/dL and 10.57 to 13.65 g/dL, respectively. This study also defined the reference ranges for reticulocyte parameters. The reference range of CBC, Ret-He, IRF, and RPI for healthy infants aged 9-11 months in this study can be used as a benchmark.

18 Prevalence of iron deficiency among extreme preterm neonates based on Reticulocyte-Hemoglobin levels: a single center cross-sectional study

Abstract Background Extreme preterm neonates are at risk of developing iron deficiency due to multiple factors including lack of third trimester placental iron accretion and frequent blood sampling. The true prevalence of iron deficiency in this cohort is not known due to lack of valid markers. Compared to Hemoglobin (Hb) derived from the entire red blood cell population (lifespan 120 days), Hb derived for reticulocytes (lifespan 3 days) is a real-time indicator of functional iron available for erythropoiesis during the previous 3-4 days. Reticulocyte-Hemoglobin (Ret-Hb) levels lower than 29pg can indicate iron deficiency in preterm neonates < 32 weeks gestation with 85% sensitivity and 73% specificity. Objectives This study aims to measure the prevalence and risk factors of iron deficiency at term equivalent age among extreme preterm neonates based on Ret-Hb levels. Design/Methods A single center retrospective chart review of neonates born at <= 29 weeks gestation between June 2016 to December 2019. All neonates received routine iron supplementation from 2 weeks postnatal age at 3-4mg/kg/day (birth weight <1Kg) or 2-3mg/kg/day (birth weight>1Kg) to a maximum of 15mg elemental iron as ferrous sulfate or iron fortified formula. Hb, Reticulocyte count, Ret-Hb, Immature reticulocyte fraction (IRF) and mean corpuscular volume (MCV) was measured at 4 weeks postnatal age, 36 weeks corrected gestation, and at discharge. Iron deficiency at term equivalent age was defined as Ret-Hb levels <= 29pg. Results Among 387 eligible neonates, 187 who had hematological parameters available at term equivalent age were included. The study cohort had a mean gestation of 25.7 (1.6) weeks, birth weight of 863 (220) g, mean SNAPPEII score of 29.2 (19), and gestational age at discharge of 42.7 (7.2) weeks. The prevalence of iron deficiency among neonates < 24 weeks, 24-25 + 6 weeks, 26-27 + 6 weeks, and >=28 weeks was 35.7%, 18.4%, 27.7%, and 15.6% respectively. Male infants were more likely to have iron deficiency at term equivalent [Table 1]. The neonates with iron deficiency had higher rates of necrotising enterocolitis [14% versus 8%], laparotomy [14% versus 10%] and postnatal steroids [69% versus 57%] compared to neonates without iron deficiency, however not statistically significant. Ret-Hb levels at 4 weeks postnatal age showed a positive correlation with Ret-Hb levels [Slope 0.58, R2 squared 0.02] and MCV levels [Slope 0.75, R2 0.11] at discharge [Figure 1]. Contrary to changes in Hb levels and reticulocyte counts, Ret-Hb levels, MCV and IFR progressively decrease from 4 wks postnatal age to discharge. Conclusion Despite routine standardized iron supplementation, extreme preterm neonates may have iron-limited erythropoiesis indicated by low Ret-Hb levels at term equivalent age. Lower levels of Ret-Hb at 4 weeks postnatal age was associated with low IRF and low MCV at discharge although Hb levels may remain within acceptable range. Future studies would need to elucidate the impact of iron deficiency at corrected term on long-term outcome. Guidelines should consider incorporating Ret-Hb levels in the workup of anemia of prematurity.

ASSESSMENT OF IMMATURE RETICULOCYTE FRACTION (IRF) WITH ABSOLUTE RETICULOCYTE COUNT (ARC) AS A RESPONSE MARKER IN ANTEPARTUM PATIENTS WITH NUTRITIONAL ANEMIA

Background: Peripheral blood reticulocyte count is an important index in the diagnosis, classication, and monitoring of anemic patients. After initiation of therapy, reticulocytosis develops within 3 to 7 days th th 1 and peaks (8–10%) between the 8 and 10 day . The IRF (Immature Reticulocyte Fraction) increases several days before reticulocyte count and is thus an early indicator of response to therapy. Aim: To study the response of therapy using IRF on day rd th th th 3 - 4 and day7 - 8 in antenatal patients with nutritional anemia. To correlate ARC (Absolute Reticulocyte Count) with IRF after therapy in antenatal patients with nutritional anemia. Study design: Prospective, analytical observational study. Materials and Methods: A total of 63 pregnant women with nutritional anemia were enrolled. Baseline samples for RBC indices, ARC and IRF were taken and treated with parental iron and Vit B12 injection accordingly. Baseline, 3rd - 4th and 7th – 8th day of therapy, values of hematological parameters along with ARC and IRF for predicting the response were determined. Results: The rise in mean ARC and IRF from baseline to day3/4 and day7/8 is signicantly higher in responders. There was a signicant positive correlation between IRF and ARC at baseline, day3/4 and day7/8. Conclusion: IRF and ARC increase in nutritional anemia in subjects, as early as 3-4 days post-therapy, however ARC on day 3-4 is an accurate prediction of response to therapy as evaluated on day 7-day 8 in the present study

Correlation Among Reticulocyte Hemoglobin, Immature Reticulocyte Fraction and Transferrin Saturation in Adult Patients with Iron-Deficiency Anemia

Iron deficiency anemia (IDA) is one of the most common forms of anemia with up to 80% of the world population suffering from it. Current widely used methods to determine IDA are hematology assay and transferrin saturation (TSAT). These methods have limitations such as they required two different specimens and could be affected by inflammation. Novel parameters such as reticulocyte hemoglobin (RET-He) could be used to measure iron reserve in bone marrow, whereas erythropoiesis is judged by immature reticulocyte fraction (IRF). Both parameters could be measured using one blood specimen. The aim of this study is to analyze the correlation between RET-He, IRF and TSAT in patients with IDA.

The importance of immature granulocyte and immature reticulocyte fraction for the severity of acute bronchiolitis

The immature granulocyte (IG) and immature reticulocyte fraction (IRF) are new analytical parameters of the complete blood count, that have been studied as biomarkers of several inflammatory conditions. Here, our aim is to determine the effectiveness of IG and IRF percentages for the severity of acute bronchiolitis (AB). A single-center, prospective study was performed in patients who were hospitalized for acute bronchiolitis and healthy children were included as a control group. The demographic characteristics, white blood cell (WBC) count, platelet (PLT) count, eosinophil%, IG%, and IRF% values were analysed. Receiver operating characteristics (ROC) analysis was used to compare the diagnostic accuracies and predictive performances. We enrolled 168 infants in the acute bronchiolitis group and 80 in the control group. The Clinical Severity Score (CSS) showed that 48, 93, and 27 patients had mild, moderate, and severe bronchiolitis, respectively. The WBC, PLT, and IRF value were significantly higher in patients (p < 0.001). There was no difference between the patients and control group in terms of IG and eosinophil percentage. Only a positive correlation was observed between the clinical severity of the AB and IRF (p=0.003).The ROC curve analysis indicated that the IRF% cut-off point for predicting severity AB was >12.4, with a sensitivity of 53% and specificity of 88% (Areas under the curves (AUC):0.701,p<0.001). The WBC count, PLT count, and IRF value increased in the AB group. The IRF percentage can be used to predict the clinical severity of AB in children.

Screening for hereditary spherocytosis in daily practice: what is the best algorithm using erythrocyte and reticulocyte parameters?

Hereditary spherocytosis (HS) is the most common inherited chronic haemolytic anaemia in Northern Europe. During the last decade, additional erythrocyte and reticulocyte parameters have been developed on last-generation haematology analysers, leading to many publications about their effectiveness as a HS screening tool. For the first time on an independent cohort, we evaluated and compared the effectiveness of six published algorithms for the screening of HS using the UniCel DxH800 (Beckman-Coulter) and the XN-9000 (Sysmex) and determined which algorithm could be the most suitable in our daily clinical practice. A total of 95 EDTA samples were analysed prospectively on both haematology analysers. These included 11 confirmed HS patients and 84 non-HS patients. The specific reticulocyte parameters used on the DxH800 were mean reticulocyte volume, immature reticulocyte fraction and mean sphered cell volume, and on the XN-9000 were hypohaemoglobinised erythrocytes, microcytic erythrocytes and immature reticulocyte fraction. The three algorithms using parameters specific to Beckman-Coulter analysers provided a sensitivity of 100% with various specificities, ranging from 7.1 to 73.8%. The three algorithms published based on the parameters specific to Sysmex showed much lower performances, i.e. out of the 11 patients with HS, between one to five patients were screened as negative for HS. However, 100% sensitivity and specificity were reached using the EMA binding test concomitantly with those three algorithms. The algorithms using reticulocyte and erythrocyte parameters offered by the recent analysers are promising options as a HS first-tier screening tool. Nevertheless, they must be evaluated by each laboratory on their own analyser before implementation.

Hematological changes in neonatal mice with phlebotomy-induced anemia.

Anemia is a nearly universal diagnosis in preterm infants, caused by phlebotomy, and exacerbated by the underlying erythropoietic immaturity. Newborn infants are exposed to the unique stressor of fetal-to-neonatal transition, which requires significant adaptation ex utero. Accordingly, the preterm infant's response to anemia may alter the ability to confront underlying illness. This study utilized our preclinical mouse model of phlebotomy-induced anemia (PIA) to comprehensively investigate associated hematological changes. C57BL/6 mice were subjected to timed phlebotomy between postnatal days 2--10 to induce severe anemia. Complete blood counts were determined by the Sysmex XT-2000iV analyzer. Anemic pups showed a gradual reduction of RBC and hemoglobin (Hb) and increased reticulocyte (RET) counts and red cell distribution width (RDW), however, with reduced RET-Hb from postnatal day (P) of 4 onwards. Elevated levels of high fluorescent RET and immature reticulocyte fraction (IRF) were noted in anemic mouse pups, but low and medium fluorescent RET were reduced. Also, the reduction of mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC) were noted in anemic pups. No changes were seen in lymphocytes, but monocytes and neutrophils were significantly elevated from P4-P6. PIA in mouse pups is associated with hematological changes that may be exacerbating factors in neonatal diseases. Anemia is common and often severe in premature infants. Investigation of hematological parameters in settings of preclinical anemia may be an index of therapeutic strategies. Preclinical model evaluating the effects of neonatal anemia on the remainder of complete blood count. Detailed time kinetic phlebotomy-induced anemic mice enable us to study the impact on developmental delays in erythropoiesis and possible strategic intervention. Hematological effects of severe anemia in mice might provide insight on how best to investigate anemia in preterm infants.

The Effect of Pre-operative Autologous Blood Donation on Bone Marrow Hematopoietic Functions in Rabbits after Hepatectomy.

Pre-operative autologous blood donation (PABD) is one of the most widely distributed autologous blood donation means, which has positive effects on erythropoiesis. However, whether PABD can stimulate the bone marrow hematopoiesis after hepatectomy has not been reported. Totally 80 New Zealand rabbits were randomly divided into 4 groups that included control group, surgery group, hemodilutional autotransfusion (HA) group and PABD group. Automatic reticulocyte examination was performed to detect the content of reticulocyte and immature reticulocyte fractions (IRF). Flow cytometric analysis was employed to monitor the level of CD34+ cells and the cell cycle status. Southern blotting was conducted to determine the telomere length of CD34+ cells. The content of high fluorescence reticulocytes (HFR) and IRF was decreased at 6 h and 24 h after autotransfusion. However, the level of CD34+ cells was upregulated after PABD. Cell cycle status analysis revealed that the majority of the CD34+ cells in HA and PABD group were maintained in G0/G1 phase. The telomere length in HA and PABD group was shortened than that of the control group and surgery group. PABD could promote the bone marrow hematopoietic functions in rabbits after hepatectomy via stimulating proliferation of CD34+ cells and shortening the telomere length of CD34+ cells, but the content of HFR was not increased immediately because of the stuck of CD34+ cells in the G0/G1 phase.

Utility of reticulocyte indices in the diagnosis of pancytopenia.

Introduction:Pancytopenia is a hematological condition in which there is a reduction in all three cell lines of blood. This study aims to evaluate the utility of reticulocyte indices such as reticulocyte % (retic %), immature reticulocyte fraction (IRF), and mean reticulocyte volume (MRV) in identifying the cause of pancytopenia.Materials and Methods:Reticulocyte indices were measured by an automated coulter. These values were then correlated with relevant biochemical and bone marrow results and cases were stratified into different etiological groups. Receiver operator curve (ROC) analysis was performed and various cut-off values were derived based on the reticulocyte indices. ROC was repeated to further classify cut-off values at every level to help formulate a diagnostic algorithm.Results:A total of 154 cases of pancytopenia were obtained. Ages ranged from 7 months to 87 years with a mean of 42, the male:female ratio was 1.08:1. The majority of the cases were megaloblastic anemias in which the cut-off values for retic % was <0.91 with a sensitivity of 78.1% and specificity of 70%, IRF was 0.45 with a sensitivity of 76.7% and specificity of 64%, and MRV was >121.8 fl with a sensitivity of 83.6% and specificity of 80%. The values on ROC could segregate nutritional from nonnutritional causes. The IRF and MRV also helped to differentiate megaloblastic anemia from dual deficiency anemia.Conclusion:Reticulocyte indices help identify the cause of pancytopenia. They can segregate nutritional anemia from other causes of pancytopenia allowing presumptive treatment to be initiated and may obviate invasive procedures such as bone marrow examination.

Identification of subclinical iron deficiency using new erythrocytes, leukocytes, and reticulocytes parameters during nonsevere acute infection in pediatric outpatients.

This study aims to investigate the diagnostic utility of new erythrocytes, leukocytes, and reticulocytes parameters for the identification of subclinical iron deficiency (ID) in children under 6 years with nonsevere acute infection in pediatric outpatients. The study included 102 children with acute infections and 31 true ID. Traditional and new hematology parameters were measured in a Sysmex-XN®, along with C-reactive protein level, and iron parameters. Participants' ID were categorized as: the ferritin < 100 ng/mL, transferrin saturation < 20% was defined as "subclinical or functional ID (FID) in Group 1"; ferritin < 30 ng/mL, transferrin saturation < 20%, as "absolute-ID (AID)" in Group 2; ferritin < 12 ng/mL without anemia and infection, as "true ID" in Group 3. The frequencies of FID and AID among the 102 children with acute infection were 24% and 76%, respectively. Compared with the Group 2 patients, Group 1 had a significantly higher mean percentage of hypochromic erythrocytes (Hypo-He), and significantly lower levels of hemoglobin (Hb) and Hb content of reticulocytes (RET-He) (p < 0.05 for all). Compared with Group 2 and Group 3 patients, Group 1 had a significantly higher mean percentage of immature reticulocyte fraction (IRF) and immature granulocyte (IG) values (p < 0.05 for all). The RET-He, IRF%, Hypo-He%, and IG% cut-off values for predicting FID during infection were 27.0 pg, 10.6%, 2.5%, and 0.35% respectively. The RET-He, Hypo-He, IRF, and IG may be useful parameters for identifying subclinical ID in small children with nonsevere acute infection in pediatric outpatients.

Manual immature reticulocyte fraction; a surrogate marker to assess post traumatic blood loss

Introduction: Erythropoietic response following chemotherapy and stem cell transplant is assessed by reticulocytosis and immature reticulocyte fraction (IRF). They are not used to assess erythropoiesis following acute haemorrhage even though it is known to cause reticulocytosis. This study was performed to evaluate the use of IRF as a marker of degree of post-traumatic haemorrhage. Methods: A cross sectional descriptive study was performed using routine anticoagulated blood samples collected from patients admitted with acute traumatic haemorrhage to an emergency treatment unit. Differential and total reticulocyte counts were performed manually using standard techniques with bright field microscopy. The data on severity of blood loss were extracted from clinical records. Results: There were total of 38 patients. Mean IRF of patients with mild (n = 14), moderate (n = 19) and severe (n = 05) haemorrhage were 1.86 ± 1.0%, 3.26 ± 1.8% and 10.2 ± 3.6% respectively. Mean manual IRF of group with severe haemorrhage was significantly higher than those of all the others (p = 0.000). The mean manual IRF of moderate haemorrhage group was significantly higher than that of mild group (p = 0.01). Manual IRF and severity of haemorrhage were significantly positively correlated (r = 0.71, p &lt; 0.01, n = 38). Immature reticulocytes of stage I was observed only in patients with severe haemorrhage. Conclusion: The manual IRF can be used as a reliable marker of severity of post-traumatic acute haemorrhage.

Reference intervals for reticulocyte parameters (reticulocyte haemoglobin equivalent and immature reticulocyte fraction) in first-trimester pregnancy

Reticulocyte parameters including reticulocyte haemoglobin equivalent (Ret-He) and immature reticulocyte fraction (IRF) are newly recognised hematological parameters that are being used for diagnosis and follow-up of anaemic patients. Reference intervals of these parameters have been established in different populations, however, the data relating to pregnancy are still lacking. One hundred and fifty-five first-trimester pregnant females were screened and the reference interval was calculated after selecting the patient with fixed criteria. R statistical software was used for statistical calculations. We tried to establish a reference interval of Ret-He content and IRF in first-trimester pregnancy in our study. IMPACT STATEMENT What is already known on this subject? Ret-He and IRF have been established as the marker of iron deficiency and iron-deficiency anaemia in different age groups and as a marker of response to iron therapy. However, literature is scarce regarding the reference intervals of these parameters, especially in pregnancy. What do the results of this study add? This study establishes the reference interval of newer reticulocyte parameters in first-trimester pregnancy which is not yet established in the literature. Establishing a reference interval is required for any laboratory parameters to be used in the clinical context. What are the implications of these findings for clinical practice and further research? The results of this study may help in making a clinical decision regarding iron deficiency in early pregnancy which is one of the common clinical problems in pregnancy. This study also serves as a baseline study for further studies of reference intervals for newer reticulocyte parameters in pregnancy. A similar study with a larger study population and follow-up with iron therapy may establish these parameters as one of the important markers of iron deficiency in pregnancy and help institute iron therapy on case-to-case basis.

Reference intervals of automated reticulocyte count and immature reticulocyte fraction in a pediatric population.

Reticulocytes are erythroid precursors that develop into mature erythrocytes, and they are an important tool to assess erythropoietic activity, as their count indicates the balance between the cells released from the bone marrow, their stage of maturity, and their rate of development into mature erythrocytes. Considering the described biological variability of the absolute reticulocyte count (ARC) and the immature reticulocyte fraction (IRF) and the limited information available on these hematological parameters in children, this study determined the reference intervals (RIs) of these parameters in a healthy pediatric population. A retrospective, observational, and analytical study was designed to establish RIs for the ARC and the IRF according to age and sex. An indirect sampling method was applied to a mixed database of complete blood counts from children aged 2months to 18years, using the truncated maximum likelihood indirect method for reference interval estimation. Percentiles were calculated to obtain bimodal RIs. From a total of 190,812samples, 6,814 were selected. Gender stratification was not necessary for the ARC and the IRF but they required partitioning into six and two age groups, respectively. This study determined, by an indirect sampling method, RIs for the ARC and the IRF in a pediatric population according to age and sex.

Difference in Immature Reticulocyte Fraction Percentage between Moderate and Severe Anemia in Transfusion-Dependent Thalassemia

Thalassemia is an inherited genetic disease caused by the disruption in globin chain synthesis. Inefective erythropoiesis in thalassemia leads to moderate to severe anemia, requiring routine blood transfusions. To evaluate erythropoiesis, immature reticulocyte fractions (IRF) can be measured using the hematology analyzer, avoiding the need of invasive bone marrow examination. The purpose of this study was to analyze the differences in the IRF percentage between moderate and severe anemia in transfusion-dependent thalassemia (TDT) patients. This was a cross-sectional comparative observational analytic study conducted at the Pediatric Thalassemia Clinic of Dr. Hasan Sadikin General Hospital Bandung in August–September 2020. The IRF was examined using the fluorescence flowcytometry method with whole blood sample added by EDTA anticoagulant. The statistical analysis used in this study was unpaired t-test and Mann Whitney’s test. Subjects were 93 TDT pediatric patients, consisting of 48 boys (52%) and 45 girls (48%). The majority (72%) of the patients had been diagnosed with thalassemia for more than 5 years with moderate anemia (40%) and severe anemia (60%). The median IRF percentage in moderate anemia was 6.4% (range 0-22.7) while the range in severe anemia was 11.7% (range 4.1–35.8), suggesting a statistically significant difference (p&lt;0.001) in the IRF percentage between moderate and severe anemia in transfusion-dependent thalassemia patients. To conclude, the more severe the anemia experienced by a thalassemia patient is, the higher the percentage of IRF.

Utility of reticulocyte haemoglobin content and immature reticulocyte fraction in early diagnosis of latent iron deficiency in whole blood donors.

The present study was planned to assess the clinical utility of reticulocyte haemoglobin content (CHr) and immature reticulocyte fraction (IRF) in the early detection of latent iron deficiency in blood donors. The prospective longitudinal observational study was conducted using the purposive sampling method. Written informed consent was obtained and donors were allocated into the first-time (FTD) and regular donor (RD) group. The enrolled blood donors (n= 205 in each group) were followed up for two subsequent whole blood donations. Haemoglobin (Hb), CHr, IRF and serum ferritin values were recorded at enrolment and two follow-ups. The sensitivity of CHr in detecting iron-deficient erythropoiesis (serum ferritin values ≤ 26 μg/dl) was 45% and 56.7%, specificity 96.7%, positive predictive value (PPV) 85.6% and 90.8% and negative predictive value (NPV) 80.1% and 78.7%, respectively in FTD and RD cohorts. The sensitivity of IRF was 45.1% and 44.8%, specificity 93.4% and 97.1%, PPV 74.8% and 90.4% and NPV 79.6% and 74.5%, respectively in both the cohorts. The sensitivity of CHr in detecting absent iron stores (serum ferritin values ≤ 15 μg/dl) was 66.2% and 74.4%, specificity 92% and 90.6%, PPV 56.7% and 68.7% and NPV 94.5% and 92.8% among FTD and RD cohort, respectively. The sensitivity of IRF was 72.7% and 65.3%, specificity 90.3% and 94.3%, PPV 54.4% and 76% and NPV 95.4% and 90.8%, respectively in both the cohorts. Reticulocyte hemoglobin content and IRF can be used along with complete blood count for early detection of iron deficiency in blood donors using the same blood sample at no extra cost.

Investigation of the correlation between immature reticulocyte fraction and reticulocyte hemoglobin content with common tests for iron deficiency anemia

Abstract Reticulocyte hemoglobin content (Ret-He, the hemoglobin within reticulocytes or immature red blood cells) and immature reticulocyte fraction (IRF, the immature fraction of the absolute-reticulocyte-count) are tests that provide insight into erythropoiesis and iron status earlier than conventional iron studies offering the added benefit of not being acute-phase-reactants. Studies have shown that Ret-He is a diagnostic marker for iron-deficiency-anemia (IDA), but fewer studies have investigated IRF. Our laboratory is currently planning to report these parameters when reticulocyte is ordered. Since these are new parameters, we wanted to investigate their overall correlation with complete blood count (CBC) and other iron studies to gain a better appreciation of their utility in our patient population. The aim of this study was to compare the overall correlation of Ret-He and IRF with seven tests used in the evaluation of IDA. To our knowledge these parameters have not all been directly correlated within a single study. CBC and reticulocytes were quantified using XN 9000 hematology analyzers (Sysmex Corporation), ferritin (DXI 800, Beckman Coulter Inc.), and % iron-saturation (measured using total iron-binding-capacity (TIBC)=transferrin*1.18 on Cobas 6000, Roche Diagnostics). Two de-identified cohorts of patients undergoing physician-ordered reticulocyte testing were used for this analysis. Dataset 1 (DS1): (N=2026 from Mayo Clinic Florida) had Ret-He and IRF compared to absolute-reticulocyte-count (Ret), ferritin and % iron saturation. Dataset 2 (DS2): (N=3990 from Mayo Clinic Rochester) had Ret-He and IRF compared to the red-cell-indices of the CBC including hemoglobin (Hgb), mean-corpuscular-volume (MCV), mean-corpuscular-hemoglobin (MCH), and mean-corpuscular-hemoglobin-concentration (MCHC). Correlation coefficients were calculated using Spearman rank-order (ρ) wherein values below +/-0.39 are weak, between +/-0.40-0.59 are considered moderate, and values above +/-0.60 are considered strong. For DS1, Ret-He demonstrated the following correlations: Ret (ρ=0.01), ferritin (ρ=0.33), % iron saturation (ρ=0.63). IRF demonstrated: Ret (ρ=0.46), ferritin (ρ=-0.05), % iron saturation (ρ=-0.22). For DS2, Ret-He demonstrated the following correlations: Hgb (ρ=0.17), MCV (ρ=0.64), MCH (ρ=0.74), MCHC (ρ=0.56). IRF demonstrated Hgb (ρ=-0.41), MCV (ρ=0.10), MCH (ρ=0.04), MCHC (ρ=-0.11). Ret-He and IRF demonstrated different correlative profiles suggesting they may have differing uses. Ret-He was strongly positively-correlated with % iron saturation, MCV, MCH and moderately positively-correlated with MCHC. These positive-correlations are consistent with relationships established in the literature. Interestingly, Ret-He was only weakly correlated with ferritin, possibly owing to ferritin being an acute-phase-reactant. IRF had a moderate positive correlation with Ret and moderate inverse correlation with Hgb. Both of these IRF relationships are consistent with other reports, but both relationships have not been shown in the same study before, preventing direct comparison until now. The literature suggests IRF may have more potential in monitoring treatment than in diagnosis. One limitation of these datasets is their lack of clinical correlation such as established iron-deficiency, anemia status, or treatment information.