Diagnosis of iron deficiency in patients undergoing hemodialysis

Correlation between ultrafiltration rate and hemoglobin level and erythropoietin response in hemodialysis patients

This study aimed to investigate the correlation between ultrafiltration rate (UFR) and hemoglobin levels and erythropoietin (EPO) response in patients receiving maintenance hemodialysis (MHD). 225 MHD patients were divided into three groups according to the UFR: < 10 ml/h/kg, 10-13 ml/h/kg, and >13 ml/h/kg. Clinical parameters and prognosis were compared among the groups. Multiple linear correlation and regression analyses were conducted. SPSS 26.0 (IBM, Chicago, IL, USA) was used to analyze all statistics. The UFR < 10 ml/h/kg group was older than the other groups (p < 0.05). The UFR > 13 ml/h/kg group had the highest SpKt/V (p < 0.05), monthly EPO dose/weight (p < 0.001), and EPO resistance index (p < 0.001), as well as the lowest dry weight (p < 0.001), BMI (p < 0.001), hemoglobin (p < 0.001), hematocrit (p < 0.05), and red blood cell count (p < 0.05). Multiple linear regression analysis showed that sex, dry weight, UFR, calcium, phosphorus, albumin, and C-reactive protein levels were associated with hemoglobin levels. Multivariate logistic regression analysis revealed that a higher UFR was associated with lower hemoglobin levels, while male sex and higher levels of calcium and albumin were associated with higher hemoglobin levels. High UFR is associated with more severe anemia and EPO resistance in MHD. This study provides new insights into anemia management in patients undergoing hemodialysis.

Evaluation of hepcidin-25/erythroferrone ratio as a potential biomarker for iron utility and erythropoiesis responsiveness to erythropoiesis-stimulating therapy in comparison to immature erythrocyte/reticulocyte parameters in hemodialysis patients

BACKGROUND

Anemia-associated chronic kidney disease increases in more advanced stages with a subsequent acceleration in renal impairment progressing to end-stage renal disease. Although hepcidin and erythroferrone have been described as novel biomarkers of iron metabolism, there is still an area of ambiguity regarding iron utility in anemia-associated end-stage renal disease.

OBJECTIVES

This study aims to determine the correlations between erythropoietin, erythroferrone, and hepcidin-25 in hemodialysis, and to evaluate the clinical utility of the hepcidin-25/erythroferrone ratio as a biomarker of erythropoiesis-stimulating agent effectiveness compared to reticulocyte maturation parameters.

METHODS

Serum erythropoietin, erythroferrone, and hepcidin-25 levels in 35 dialysis-dependent patients on a maintenance dose of a short-acting erythropoiesis-stimulating agent were consequently assessed on Days 0, 5, and 7. The erythropoiesis activity was monitored by measuring the increment in reticulocyte maturation parameters.

RESULTS

Though the effectiveness of erythropoiesis in these patients was not associated with the hepcidin-25/erythroferrone ratio, it was lower among those with effective erythropoiesis than those with ineffective erythropoiesis. The effective group showed a statistically significant increase in reticulocyte maturation parameters compared to the ineffective group.

CONCLUSIONS

The findings show the pathogenesis of iron homeostasis in hemodialysis, the validity of hepcidin-25/erythroferrone ratio as a biomarker of erythropoiesis-stimulating agent effectiveness, and the advantageous monitoring of reticulocyte maturation measures to improve management of anemia-associated chronic kidney disease.

Iron Indices Mediate but Not Modify Association of Parathyroid Hormone with Erythropoietin Resistance in Hemodialysis Patients

INTRODUCTION

Disordered iron balance and abnormal parathyroid hormone (PTH) concentrations, both prevalent in hemodialysis patients, are risk factors of erythropoietin (EPO) resistance. Few studies have evaluated the correlation between iron indices and PTH and the potential role of iron markers on the association of PTH with EPO resistance in hemodialysis population.

METHODS

In this cross-sectional study of 71 maintenance hemodialysis patients, iron indices including hepcidin, ferritin, reticulocyte hemoglobin content (CHr), and transferrin saturation (TSAT) were examined. EPO responsiveness was measured as EPO resistance index (ERI). Lowess regression curves were performed to explore the correlations of iron indices, PTH, and ERI. The association between PTH and ERI was modeled using linear regressions. Potential role of iron indices on this association was examined using stratified analyses and mediation analyses.

RESULTS

The average ERI value was 10.3 ± 5.3 IU w-1 kg-1 (g/dL) -1. ERI was correlated to PTH, hepcidin, CHr, and TSAT (all p < 0.05). Hepcidin and PTH were closely correlated with each other (r = 0.28, p = 0.020). Analysis by PTH categories yielded a total association effect of 2.53 (95% CI: 0.27-4.85, p = 0.027) for high PTH subgroup versus the reference low subgroup. No clinically significant interaction between iron indexes and PTH was identified. Hepcidin appeared to mediate about one-third of the total association between PTH and ERI in hemodialysis population (33.6%, p = 0.025).

CONCLUSION

Iron indices and PTH levels were related to ERI values. Hepcidin appeared to be closely correlated to PTH and partly mediate the association between PTH and ERI in hemodialysis population.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Low-Dose Oral Iron Replacement Therapy Is Effective for Many Japanese Hemodialysis Patients: A Retrospective Observational Study

Western guidelines recommend the use of intravenous iron supplementation for hemodialysis patients. However, in Japanese patients with well-controlled inflammation, iron replacement may be achieved with oral iron supplementation. This study involved 108 courses in 77 outpatient hemodialysis patients who received low-dose oral iron replacement therapy. Data from baseline to week 28 of treatment were analyzed to identify factors associated with effectiveness. Changes over time in erythrocyte- and iron-related parameters and erythropoiesis-stimulating agent (ESA) dose were investigated in the effective group. A total of 84 courses (77.8%) satisfied the effectiveness criteria. Compared with the effective and ineffective groups, only C-reactive protein (CRP) was significantly different (p < 0.01). ROC curve analysis with efficacy as the endpoint showed a CRP cut point value of ≤0.1 mg/dL (area under the curve, 0.69; 95% confidence interval, 0.57−0.81). The relationship between serum ferritin and hemoglobin fluctuation by reducing the ESA dose showed a positive correlation (p < 0.001). In the ESA maintenance group, the serum ferritin gradually increased and then remained constant at about 60 ng/mL. Our data suggest that patients with CRP ≤ 0.1 mg/dL may benefit from low doses of oral iron supplementation. Approximately 60 ng/mL serum ferritin may be sufficient during stable hematopoiesis.

Evaluation of Predicting the Value of the Reticulocyte Hemoglobin Equivalent for Iron Deficiency in Chronic Kidney Disease Patients

Background: Iron management is essential for anemia treatment in chronic kidney disease. The reticulocyte hemoglobin equivalent (RET-He) is a reticulocyte parameter that reflects hemoglobin synthesis of newly formed erythrocytes in the bone marrow in real-time. Objectives: This study aims to evaluate the role of reticulocyte hemoglobin equivalent (RET-He) in predicting iron deficiency in chronic kidney disease (CKD) patients. Methods: Following a descriptive cross-sectional observational design, this study was conducted on 131 adult patients with CKD stages 3 - 5. Laboratory indices, including complete blood count, some biochemical indices, iron status, and reticulocyte indices (including RET-He), were measured. Iron deficiency (ID) was defined as TSAT < 20%, where serum ferritin level > 100 ng/mL was defined as functional ID, while serum ferritin level

Anemia in Pediatric Kidney Transplant Recipients-Etiologies and Management

Posttransplant anemia (PTA) is a common complication of pediatric kidney transplantation, with a prevalence ranging from 22 to 85%. PTA is categorized as early (within 6 months posttransplant) and late (>6 months posttransplant). Early PTA is typically associated with surgical blood losses and iron deficiency. Late PTA primarily results from graft dysfunction; however, iron deficiency, drug toxicity, and posttransplant inflammation also play a role. PTA is more severe compared with the anemia in glomerular-filtration-rate matched patients with native chronic kidney disease. Treatment of PTA is directed toward the underlying cause. Erythropoiesis stimulating agents (ESA) are effective; however, their use is limited in the transplant setting. Timely diagnosis and treatment of PTA are vital to prevent long-term adverse outcomes in pediatric transplant recipients.

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.

Hypochromic red cells as predictors of anemia in patients undergoing hemodialysis: an observational retrospective study

The percentage of hypochromic red blood cells (%HRC) estimates the availability of iron by evaluating the degree of hemoglobinization. We investigated whether %HRC was a predictor of anemia in patients undergoing hemodialysis. We recruited 142 patients undergoing routine hemodialysis between 2017 and 2019. Delta hemoglobin level (ΔHb)_1mo-baseline was calculated as the difference between the hemoglobin level at 1 month after study enrollment and that at the time of study enrollment. Development of anemia was defined as hemoglobin level ≤ 15% of baseline. The median %HRC was 3.1%. There was a significant negative correlation between (ΔHb)_{1mo- baseline} and %HRC (r =  − 0.63, P < 0.001). The incidence of anemia was significantly higher in patients with %HRC > 3.1% than in those with %HRC ≤ 3.1%. In the multivariate logistic regression analysis, %HRC was significantly related to the development of anemia (odds ratio 2.57, 95% confidence interval [CI] 1.72–3.85, P < 0.001). The best cutoff value for %HRC to predict the development of anemia was 4.3%, with a sensitivity and specificity of 67.74 (95% CI, 54.7–79.1) and 97.50 (95% CI, 91.3– 99.7), respectively. %HRC is an independent predictor of anemia in patients undergoing hemodialysis. %HRC ≤ 4.3% is an early marker to consider changing the anemia treatment.

Neonatal Reference Intervals for the Complete Blood Count Parameters MicroR and HYPO-He: Sensitivity Beyond the Red Cell Indices for Identifying Microcytic and Hypochromic Disorders

OBJECTIVE

To create neonatal reference intervals for the MicroR and HYPO-He complete blood count (CBC) parameters and to test whether these parameters are sensitive early markers of disease at early stages of microcytic/hypochromic disorders while the CBC indices are still normal.

STUDY DESIGN

We retrospectively collected the CBC parameters MicroR and HYPO-He, along with the standard CBC parameters, from infants aged 0-90 days at Intermountain Healthcare hospitals using Sysmex hematology analyzers. We created reference intervals for these parameters by excluding values from neonates with proven microcytic disorders (ie, iron deficiency or alpha thalassemia) from the dataset.

RESULT

From >11 000 CBCs analyzed, we created reference intervals for MicroR and HYPO-He in neonates aged 0-90 days. The upper intervals are considerably higher in neonates than in adults, validating increased anisocytosis and polychromasia among neonates. Overall, 52% of neonates with iron deficiency (defined by reticulocyte hemoglobin equivalent <25 pg) had a MicroR >90% upper interval (relative risk, 4.14; 95% CI, 3.80-4.53; P < .001), and 68% had an HYPO-He >90% upper interval (relative risk, 6.64; 95% CI, 6.03-7.32; P < .001). These 2 new parameters were more sensitive than the red blood cell (RBC) indices (P < .001) in identifying 24 neonates with iron deficiency at birth.

CONCLUSIONS

We created neonatal reference intervals for MicroR and HYPO-He. Although Sysmex currently designates these as research use only in the US, they can be measured as part of a neonate's CBC with no additional phlebotomy volume or run time and can identify microcytic and hypochromic disorders even when the RBC indices are normal.

A New Indicator Derived From Reticulocyte Hemoglobin Content for Screening Iron Deficiency in an Area Prevalent for Thalassemia

OBJECTIVE

To establish a new indicator derived from reticulocyte hemoglobin (Ret-He) content and red blood cell (RBC) indices for screening for iron deficiency anemia (IDA) in an area in whch thalassemia is prevalent.

METHODS

Blood specimens from 304 women aged between 18 and 30 years residing in northeast Thailand were collected and measured for RBC and reticulocyte parameters. Iron deficiency was diagnosed when a participant had a serum ferritin level of less than 15 ng per mL. Thalassemia genotypes were defined by hemoglobin (Hb) and DNA analyses.

RESULTS

Of the total participants, 25% had iron deficiency (ID) and 50% carried the thalassemia gene. Various mathematical formulas were established and analyzed using the receiver operating characteristic (ROC) curve. The formula derived from Ret-He: (Ret-He/RDW-SD) × 10, was the best predictor for identifying ID among participants (area under the curve [AUC] = 0.812). Further testing of this indicator among individuals with positive thalassemia-screening results revealed stronger performance with an AUC of 0.874.

CONCLUSIONS

The findings indicate that the formula derived from Ret-He might be applicable for screening ID in areas in which thalassemia is prevalent.

The Role of Reticulocyte Hemoglobin Content for the Diagnosis of Functional Iron Deficiency in Hemodialyzed patients

The effectiveness of reticulocyte hemoglobin content (CHr) had been reported to detect early functional iron deficiency especially among Chronic kidney disease (CKD) patients. CHr is more superior to classic biochemical indices in reflecting transient iron-deficiency status, therefore improving diagnosis and treatment. This study was conducted to determine the sensitivity of CHr in the diagnosis of functional iron deficiency (FID) in hemodialyzed patients. One hundred hemodialyzed patients along with 60 healthy controls were recruited and blood specimens were collected. Venous blood was used for hematological and biochemical investigations collected via 3 ml lavender-top tubes for hematological tests including CBC, blood film, ESR and CHr, and red-top tube for biochemical tests including TIBC, SF and CRP. A statistically significant decrease was noted in CHr values between hemodialysis patients and the control group (24.8 ± 2.0 pg vs. 30.9 ± 1.3 pg, p<0.001). CHr values showed a significant correlations with RBCs, Hb- hemoglobin, Hct- hematocrit level, MCV- mean corpuscular volume, MCH- mean corpuscular hemoglobin, MCHC, RDW- red cell distribution width , SI-Serum Iron, TIBC- Total iron binding capacity and TSAT- Transferrin saturation. The present study showed that CHr in comparison to the conventional hematological and biochemical markers commonly used to diagnose iron deficiency.

Haematological disorders following kidney transplantation

Transplantation offers cure for some haematological cancers, end-stage organ failure, but at the cost of long-term complications. Renal transplantation is the best-known kidney replacement therapy and it can prolong end-stage renal disease patient lives for decades. However, patients after renal transplantation are at a higher risk of developing different complications connected not only with surgical procedure but also with immunosuppressive treatment, chronic kidney disease progression and rejection processes. Various blood disorders can develop in post-transplant patients ranging from relatively benign anaemia through cytopenias to therapy-related myelodysplasia and acute myeloid leukaemia (AML) and post-transplant lymphoproliferative disorders followed by a rare and fatal condition of thrombotic microangiopathy and haemophagocytic syndrome. So far literature mainly focused on the post-transplant lymphoproliferative disease. In this review, a variety of haematological problems after transplantation ranging from rare disorders such as myelodysplasia and AML to relatively common conditions such as anaemia and iron deficiency are presented with up-to-date diagnosis and management.

Red Blood Cells and Platelets Conventional and Research Parameters: Stability Remarks Before Their Interpretation

OBJECTIVES

To analyze the stability of red blood cells, platelets, and reticulocytes of the research parameters, in combination with the respective conventional parameters, for each analyte; and to quantify the morphological changes in these analytes, to propose a correction factor for each.

METHODS

Ethylenediaminetetraacetic acid (EDTA) blood specimens from patients were reanalyzed in 2-hour intervals and then, the mean percentage (X¯t%) changes were calculated. To evaluate the stability of the analyzed material, we used different criteria according to within-run and between-batch analytical variation, as well as intraindividual biological variation. Next, the mean deviation percentage of the parameters that undergo time-dependent significant changes was calculated, to obtain a correction factor.

RESULTS

Several conventional and research parameters showed significant alterations in the stability at an early time after arrival at the laboratory.

CONCLUSION

Cell variations over time can be quantified and corrected by applying a multiplying factor to the signal obtained in the analyzer.

Increased Hepcidin Levels During a Period of High Training Load Do Not Alter Iron Status in Male Elite Junior Rowers

The liver-derived hormone hepcidin plays a key role in iron metabolism by mediating the degradation of the iron export protein ferroportin 1 (FPN1). Circulating levels of hepcidin and the iron storage protein ferritin are elevated during the recovery period after acute endurance exercise, which can be interpreted as an acute phase reaction to intense exercise with far-reaching consequences for iron metabolism and homeostasis. Since absolute and functional iron deficiency (ID) potentially lead to a loss of performance and well-being, it is surprising that the cumulative effects of training stress on hepcidin levels and its interplay with cellular iron availability are not well described. Therefore, the aim of this study was to determine serum levels of hepcidin at six time points during a 4-week training camp of junior world elite rowers preparing for the world championships and to relate the alterations in training load to overall iron status determined by serum ferritin, transferrin, iron, and soluble transferrin receptor (sTfR). Serum hepcidin levels increased significantly (p = 0.02) during the initial increase in training load (23.24 ± 2.43 ng/ml) at day 7 compared to the start of training camp (11.47 ± 3.92 ng/ml) and turned back on day 13 (09.51 ± 3.59 ng/ml) already, meeting well the entrance level of hepcidin at day 0. Serum ferritin was significantly higher at day 7 compared to all other timepoints with exception of the subsequent time point at day 13 reflecting well the time course pattern of hepcidin. Non-significant changes between training phases were found for serum iron, transferrin, and sTfR levels as well as for transferrin saturation, and ferritin-index (sTfR/log ferritin). Our findings indicate that hepcidin as well as ferritin, both representing acute phase proteins, are sensitive to initial increases in training load. Erythropoiesis was unaffected by iron compartmentalization through hepcidin. We conclude that hepcidin is sensitive to rigorous changes in training load in junior world elite rowers without causing short-term alterations in functional iron homeostasis.

Diagnosis of iron deficiency in hemodialysis patients: Usefulness of measuring reticulocyte hemoglobin equivalent

The evaluation of iron status in dialysis patients provides information essential to the planning of adequate recombinant human erythropoietin treatment. To diagnose iron deficiency in patients undergoing hemodialysis (HD), reticulocyte hemoglobin content and percentage of hypochromic red cells are incorporated into the European best practice guidelines on anemia management in chronic kidney disease (CKD), the mean reticulocyte hemoglobin content (Ret-HE) was proposed as alternatives to standard biochemical tests. Reticulocyte hemoglobin content and percentage of hypochromic red cells are incorporated into the European best practice guidelines on anemia management in CKD. Our aim was to assess the value of Ret-HE parameter, in terms of the sensitivity and specificity for detecting iron deficiency, in HD patients. We studied 50 patients undergoing HD three times weekly , to clarify the accuracy of Ret-HE in diagnosing iron deficiency in dialysis patients, we initially compared Ret-HE with such iron parameters as serum ferritin levels, transferrin saturation, and hypochromic red blood cell (Hypo%) which has been established as indicators of functional iron deficiency. Ret-HE mean value in anemic patients was (25.84 ± 4.23 pg) and had good correlation (P <0.001) between Ret-HE, serum iron, ferritin, transferrin, and transferin saturation in dialysis patients. Receiver operating characteristic curve analysis revealed, values of the area was 0.887, and at a cutoff value of 27.0 pg, a sensitivity of 90.4% and a specificity of 80.8% were achieved. The newly proposed Ret-HE can provide clinicians with information equivalent to iron deficiency anemia markers. Ret-HE is a new parameter that is easily measurable is suggested as reliable parameters for the study of erythropoiesis status in HD patients.

Subclinical Iron Deficiency in Non-Anemic Individuals: A Retrospective Analysis of Korean Health Examinees

OBJECTIVES

Non-anemic individuals may have undetected subclinical iron deficiency (SID). The aims of this study were to determine the prevalence of SID and identify the associated factors for SID. In addition, the screening performance of red blood cell (RBC) indices for SID in health check-ups was assessed.

METHODS

This study was conducted with 16,485 non-anemic health examinees (3,567 males and 12,918 females) who underwent tests for iron variables (serum iron, total iron-binding capacity, ferritin, and iron saturation) at 16 health-promotion centers in 13 cities in Korea between January 2017 and June 2018. SID was defined as a decreased ferritin level (<24 µg/L in males and <15 µg/L in females) and either a decreased serum iron level (<44 µg/dL in males and <29 µg/dL in females) or a transferrin saturation of <20%.

RESULTS

The prevalence rates of SID were 0.6 and 3.3% in males and females, respectively. In terms of age and sex, SID was most prevalent in males aged ≥70 years (7.8%) and females aged 15-49 years (7.6%). There were significant differences in the hemoglobin (Hb) level, white blood cell count, platelet count, mean corpuscular volume, mean corpuscular Hb (MCH), and RBC distribution width (RDW) between the SID and non-SID groups (p < 0.001). The factors associated with SID in males were older age (odds ratio, OR, 1.069, 95% confidence interval, CI, 1.03-1.109, p = 0.004), lower Hb (OR 0.58, 95% CI 0.345-0.976, p = 0.04), lower MCH (OR 0.433, 95% CI 0.298-0.629, p < 0.001), and higher RDW (OR 1.374, 95% CI 1.001-1.887, p = 0.049), while in females they were lower body mass index (BMI; OR 0.929, 95% CI 0.895-0.963, p < 0.001) and younger age (OR 0.954, 95% CI 0.945-0.963, p < 0.001), as well as lower Hb, lower MCH, and higher RDW. The AUC for the MCH (0.877, 95% CI 0.793-0.960 in males; 0.872, 95% CI 0.853-0.890 in females) indicates that the MCH at cut-offs of 29.2 and 29.3 pg are the best discriminators of SID in males and females, respectively (p < 0.001).

CONCLUSIONS

Reproductive-age females with a lower BMI and elderly males are high-risk groups for SID. MCH is a reliable RBC index for the screening of SID. For the population with defined risk factors, including females with lower BMI and elderly males, screening for SID is needed to prevent the development of anemia.

Functional iron deficiency markers are absent during pregnancy despite evidence of low iron stores

Introduction

Functional iron deficiency parameters predict iron-restricted erythropoiesis more precisely than ferritin. Ferritin and erythropoiesis can be affected by inflammation and hormonal alterations. We hypothesize that the association between low ferritin concentrations and iron-restricted erythropoiesis is not comparable between pregnant and non-pregnant women.

Materials and methods

Pregnant women ( n = 926) were included at week 12 of gestation. Ferritin concentrations, %hypochromic erythrocytes (%HYPO), %microcytic erythrocytes (%MICRO), reticulocyte haemoglobin content (MCHr), mean cell volume (MCV) and mean cell haemoglobin (MCH) were analysed. Data were compared with non-pregnant women ( n = 1302).

Results

Functional iron deficiency parameters (%HYPO, %MICRO, MCHr) were present in, respectively, 3.9%, 14.3% and 2.3% off all pregnant women. Univariate analysis of low ferritin (<20 μg/L) showed significant differences between non-pregnant versus pregnant women; %HYPO (10.92% vs. 0.92%), increased %MICRO (4.33% vs. 1.00%) and decreased MCHr (24.9 pg vs. 29.5 pg), respectively. In the logistic regression analysis, MCHr, %MICRO and MCV were independently associated with low ferritin concentrations in pregnant women, while %HYPO and %MICRO were independently associated variables in non-pregnant women with low ferritin concentrations.

Discussion

Functional iron deficiency is significantly less frequent in pregnant women compared with iron-deficient non-pregnant women. During pregnancy, iron metabolism might be differentially regulated for optimal fetal growth and development despite low maternal iron stores.

Percentage of hypochromic red cells as a potential screening test to evaluate iron status in blood donors

INTRODUCTION

Haemoglobin (Hb) levels are used to assess eligibility for blood donation but are not correlated with iron status. The percentage of hypochromic red cells (%Hypo-He) has been suggested as a useful screening parameter for iron deficiency. The aim of this study was to determine the cut-off level and accuracy of %Hypo-He screening among blood donors.

MATERIALS AND METHODS

A total of 170 blood donors were recruited into the study. Blood donors were classified into three groups: normal, latent iron deficiency and iron deficiency anaemia based on their Hb, serum ferritin and transferrin saturation (TSAT) levels. The diagnostic performance of %Hypo-He was evaluated with a validation group comprising 160 blood donors.

RESULTS

Receiver operating characteristic (ROC) curve analysis showed that %Hypo-He is an excellent parameter for detecting iron deficiency, with an area under the curve (AUC) of 0.906, a confidence interval (CI) of 0.854-0.957 at a cut-off of 0.6%, and 74.51% sensitivity and 88.24% specificity. A moderate negative correlation between %Hypo-He and TSAT (ρ = -0.576 [P < 0.001]) and a strong negative correlation between %Hypo-He and serum ferritin (ρ = -0.703 [P < 0.001]) were found. A cut-off value of 0.6% was applied to the validation group and showed 82.9% sensitivity and 96% specificity.

CONCLUSION

%Hypo-He with a cut-off value of 0.6% is a potential parameter with high sensitivity and specificity for evaluating iron status among blood donors. This parameter is suitable for screening because its measurement has a faster turnaround time than biochemical markers.

Comparison of Methods Study between a Photonic Crystal Biosensor and Certified ELISA to Measure Biomarkers of Iron Deficiency in Chronic Kidney Disease Patients

The total analytical error of a photonic crystal (PC) biosensor in the determination of ferritin and soluble transferrin receptor (sTfR) as biomarkers of iron deficiency anemia in chronic kidney disease (CKD) patients was evaluated against certified ELISAs. Antigens were extracted from sera of CKD patients using functionalized iron-oxide nanoparticles (fAb-IONs) followed by magnetic separation. Immuno-complexes were recognized by complementary detection Ab affixed to the PC biosensor surface, and their signals were followed using the BIND instrument. Quantification was conducted against actual protein standards. Total calculated error (TEcalc) was estimated based on systematic (SE) and random error (RE) and compared against total allowed error (TEa) based on established quality specifications. Both detection platforms showed adequate linearity, specificity, and sensitivity for biomarkers. Means, SD, and CV were similar between biomarkers for both detection platforms. Compared to ELISA, inherent imprecision was higher on the PC biosensor for ferritin, but not for sTfR. High SE or RE in the PC biosensor when measuring either biomarker resulted in TEcalc higher than the TEa. This did not influence the diagnostic ability of the PC biosensor to discriminate CKD patients with low iron stores. The performance of the PC biosensor is similar to certified ELISAs; however, optimization is required to reduce TEcalc.

Reticulocyte Hemoglobin Content Helps Avoid Iron Overload in Hemodialysis Patients: A Retrospective Observational Study

BACKGROUND/AIM

Anemia in patients suffering from end-stage renal failure is currently treated with Erythropoiesis-Stimulating Agents (ESA). This treatment needs sufficient iron supplementation to avoid an inadequate dosage of ESA. Nowadays modern analytical instruments allow to accurately calculate the content of Hemoglobin (Hb) in reticulocytes (CHr), that can be used as a guide for prescribing patients with the appropriate amount of iron.

PATIENTS AND METHODS

Patients, undergoing hemodialysis, were retrospectively selected from the database and were divided in two groups: group A received intravenous (IV) iron and subcutaneously ESA, and their dosages were adjusted on the basis of the following parameters: Hb, Mean corpuscular haemoglobin (MCH), CHr with consequent MCH/CHr ratio and reticulocyte count determined by the ADVIA 120 Hematology System of Siemens; group B patients were administered IV iron and ESA monitoring iron storage, Hb and ferritin. The aforementioned parameters and the administered amount of iron and ESA were monitored at baseline, four and eight months from the begining of the study.

RESULTS

For ESA supplementation, no difference was observed between the groups at the various observed times. Despite similar Hb levels, the patients of group A needed significant lower doses of IV iron (-57.8%) avoiding risks of organ toxicity and obtaining consequent cost saving of nearly 1 €/patient/month.

CONCLUSION

The use of CHr and its related parameters allows the avoidance of overdosage of IV iron, which can potentially damage organs, and the reduction of health care direct and indirect costs.

Reticulocyte Hemoglobin Content During the First Month of Life in Critically Ill Very Low Birth Weight Neonates Differs From Term Infants, Children, and Adults

BACKGROUND

Reticulocyte hemoglobin content (RET-He)-an established indicator of iron status in children and adults-was determined in very low birth weight (VLBW) infants.

METHODS

Longitudinal retrospective RET-He data in 26 VLBW neonates during the first month of age were compared with: (a) concurrent complete blood counts (CBCs), including hemoglobin (Hb) concentration, reticulocyte count, and immature reticulocyte fraction (IRF), and erythropoietin (EPO) levels; (b) clinical variables; and (c) RET-He data from the literature for term infants, children, and adults.

RESULTS

RET-He within 24 hr following birth was 31.8 ± 1.1 pg (mean ± SEM). This was followed by an abrupt, significant decline to 28.3 ± 1.1 pg at 2-4 days, and to steady state levels of 28.4 ± 0.5 pg thereafter. The changes in RET-He were mirrored by changes in plasma EPO, reticulocyte count, and IRF, but not Hb. Steady state RET-He values after 4 days were significantly lower than RET-He values for term infants, children, and adults (31.6 ± 0.11, 32.0 ± 0.12, and 33.0 ± 0.13 pg, respectively).

CONCLUSION

Although RET-He values in VLBW infant were lower than term infants, children, and adults, the significance and mechanism(s) responsible are unknown. The present VLBW infant data are relevant to investigations assessing hemoglobinization following treatment with recombinant human EPO (r-HuEPO) and/or iron.

Laboratory diagnosis of anemia: are the old and new red cell parameters useful in classification and treatment, how?

INTRODUCTION

Anemia is a global problem affecting the population in both developing and developed countries, and there is a debate on which hemoglobin level limit should be used to define anemia in general population and particularly in the elderly. We present herein a laboratory approach to diagnosing the possible causes of anemia based on traditional and new erythroid parameters. In this article, we provide practical diagnostic algorithms that address to differential diagnosis of anemia. Based on both morphological and kinetic classifications, three patterns were considered: microcytic, normocytic, and macrocytic.

METHODS

Main interest is on the clinical usefulness of old and new parameters such as mean cell volume (MCV), red blood cell distribution width (RDW), hypochromic and microcytic erythrocytes, immature reticulocyte fraction (IRF), and some reticulocyte indices such as reticulocyte hemoglobin content and mean reticulocyte volume. The pathophysiologic basis is reviewed in terms of bone marrow erythropoiesis, evaluated by reticulocyte count (increased or normal/decreased) and IRF. The utility of reticulocyte indices in the diagnosis of iron-deficient erythropoiesis (absolute or functional) and in monitoring of response to treatment in nutritional anemia (iron and cobalamin) was also investigated.

RESULTS

For each parameter, the availability, the possible clinical applications, and the limitations were evaluated. A discussion on intraindividual biological variation and its implication on the usefulness of conventional reference intervals and in longitudinal monitoring of the patients was also reported.

CONCLUSION

Red cell parameters and reticulocyte indices play an essential role in differential diagnosis of anemia and in its treatment. More efforts are needed in harmonizing parameters whose results are still too different when produced by different analyzers.

Determination of functional iron deficiency status in haemodialysis patients in central South Africa

INTRODUCTION

Functional iron deficiency (FID) is characterized by adequate body iron stores with an inadequate rate of iron delivery for erythropoiesis. In chronic kidney failure (CKD), iron availability is best assessed using the percentage of hypochromic red cells (%Hypo). The aim of our study was to determine the FID status of haemodialysis patients in central South Africa, using the %Hypo analyte and to evaluate the ability of the currently used biochemical tests, transferrin saturation (TSat) and serum ferritin to diagnose FID.

METHODS

For this study, 49 patients on haemodialysis were recruited. Haemoglobin (Hb), mean cell volume (MCV) and %Hypo were measured on the Advia 2120i. Biochemical analytes (serum ferritin, TSat) and C-reactive protein (CRP) levels were also recorded.

RESULTS

Of the 49 participants, 21 (42.9%) were diagnosed with FID (%Hypo >6%). A large number of patients (91.8%) were anaemic. The TSat demonstrated poor sensitivity and specificity for diagnosing FID compared with %Hypo. The use of %Hypo (rather than TSat) to guide intravenous iron use spared 16 patients the potential harmful effects thereof.

CONCLUSION

Using %Hypo as a single analyte to diagnose FID will lead to more appropriate use of limited resources and a reduction in treatment-related complications.

Comparison of reticulocyte hemoglobin equivalent with traditional markers of iron and erythropoiesis in pediatric dialysis

BACKGROUND

Anemia is a major complication for patients on chronic dialysis. Erythropoietin is effective if iron is available, however unnecessary iron supplementation results in iron overload. Reticulocyte hemoglobin equivalent (Ret-He) may be useful for assessing iron status.

METHODS

A national retrospective cohort study including all children on chronic dialysis in New Zealand between 2007 and 2013, pairing Ret-He with demographic information, anemia indices, and markers of iron status.

RESULTS

In 606 observations, we found a modest relationship between Ret-He and transferrin saturation (TSAT) (r = 0.34, p < 0.001) and a poor correlation between Ret-He and ferritin (r = 0.09, p = 0.04). There was a negative correlation between ferritin and hemoglobin (r = -0.14, p = 0.002), a weak positive correlation between TSAT and hemoglobin (r = 0.12, p = 0.007), and a modest positive correlation between Ret-He and hemoglobin (r = 0.22, p < 0.001). The diagnostic performance of Ret-He to detect absolute iron deficiency (cut-off value 28.9 pg, sensitivity 90 %, specificity 75 %, AUC 0.87) was good.

CONCLUSIONS

Ret-He is a more relevant marker of iron status than ferritin and TSAT. This supports prospectively testing Ret-He to distinguish between iron deficiency and suboptimal erythropoietin dosing as competing causes for anemia. Ferritin is an unhelpful biomarker of iron deficiency in this setting.

Evaluation of the hypochromic erythrocyte and reticulocyte hemoglobin content provided by the Sysmex XE-5000 analyzer in diagnosis of iron deficiency erythropoiesis

Background:

Iron deficiency represents the most frequent cause of anemia. To diagnose iron deficiency some biochemical tests such as serum ferritin and the transferring saturation percent (TSAT%) are usually used. Recently, some hematological parameters such as mean reticulocyte hemoglobin content (CHr or Ret-He) and percentage of hypochromic RBCs (Hypo% or %Hypo-He) were proposed as alternative to biochemical tests. In this study, the analytic performance and the diagnostic efficiency of these two parameters provided by Sysmex XE5000 analyzer on iron deficiency patients with or without anemia (IDA and ID, respectively) were evaluated.

Methods:

One hundred and sixty-four healthy adults, 58 with IDA, 21 with iron depleted stores (ID), 23 with β-thalassemia trait, and 24 with non iron deficiency anemia were selected. The gold standard used to define iron deficiency was the coexistence of serum ferritin below 15 μg/L (12 in women) and TSAT <16%.

Results:

For %Hypo-He, the best cut-off value for both IDA and ID is 0.9% while for Ret-He is 30.6 pg. For both parameters the performance was better to diagnose IDA (AUC, 0.96 and 0.98) than ID (AUC, 0.93 and 0.95). The Ret-He behavior was always slightly better than that of %Hypo-He.

Conclusions:

The use of these two parameters is useful to detect iron deficiency conditions if the hemoglobin synthesis has already been compromised.

Laboratory and genetic assessment of iron deficiency in blood donors

More than 9 million individuals donate blood annually in the United States. Between 200 and 250 mg of iron is removed with each whole blood donation, reflecting losses from the hemoglobin in red blood cells. Replenishment of iron stores takes many months, leading to a high rate of iron depletion. In an effort to better identify and prevent iron deficiency, blood collection centers are now considering various strategies to manage donor iron loss. This article highlights laboratory and genetic tests to assess the iron status of blood donors and their applicability as screening tests for blood donation.

Using the hemoglobin content of reticulocytes (RET-He) to evaluate anemia in patients with cancer

OBJECTIVES

Evaluation of anemia, particularly iron deficiency, in patients with cancer is difficult. This study examined using the hemoglobin content of reticulocytes (RET-He) to rule out iron deficiency, as defined by serum iron studies (transferrin saturation <20%, serum iron <40 μg/dL, and ferritin <100 ng/mL), in an unselected cancer patient population.

METHODS

Patients were entered into the study based on the existence of concurrent laboratory test requests for CBC and serum iron studies.

RESULTS

Using a threshold of 32 pg/cell, RET-He ruled out iron deficiency with a negative predictive value (NPV) of 98.5% and 100%, respectively, in the study population (n = 209) and in a subpopulation of patients with low reticulocyte counts (n = 19). In comparison, the NPV of traditional CBC parameters (hemoglobin, <11 g/dL; mean corpuscular volume, <80 fL) was only 88.5%.

CONCLUSIONS

These results support the use of RET-He in the evaluation of iron deficiency in a cancer care setting.

Delta-He: a novel marker of inflammation predicting mortality and ESA response in peritoneal dialysis patients

BACKGROUND

Inflammation impairs erythropoiesis, iron availability and is associated with a higher mortality risk in patients with end-stage renal disease. We studied the associations between Delta-He [the difference between the reticulocyte haemoglobin content (Ret-He) and erythrocyte haemoglobin content], a suggested marker of iron availability, and markers of inflammation, iron status, response to erythropoiesis-stimulating agents (ESAs) and mortality in prevalent peritoneal dialysis (PD) patients.

METHODS

Eighty-two PD patients were followed weekly for 12 weeks with an additional follow-up of 36 months. Delta-He, Ret-He and high-sensitivity C-reactive protein (hs-CRP) were measured weekly and interleukin-6 (IL-6) and iron markers every fourth week. Mortality risk was assessed by Cox proportional hazards model adjusting for potential confounding factors. The relationships between ESA response, inflammatory markers, iron markers and Delta-He were evaluated in the PD patients. The relationship between Delta-He and iron markers was analysed in 87 healthy subjects.

RESULTS

Delta-He correlated with IL-6 (rho = 0.48, P < 0.001), hs-CRP (rho = 0.36, P < 0.001) and ESA hyporesponsivess index (EHRI; rho = -0.44, P < 0.001) in the PD patients. Delta-He did not correlate with iron markers in PD patients nor in healthy subjects. The mean Delta-He levels were significantly different between the tertiles of EHRI (P < 0.01). Delta-He was associated with all-cause mortality risk in PD patients after adjusting for age, gender, hs-CRP, comorbidity and nutritional status [OR 0.70 (0.51-0.96), P < 0.05].

CONCLUSIONS

Delta-He independently predicts all-cause mortality in PD patients after adjusting for potential confounders and is a predictor of ESA response in PD patients.

Efficacy and safety of intravenous iron therapy for functional iron deficiency anemia in hemodialysis patients: a meta-analysis

BACKGROUND

Studies on benefits of intravenous iron therapy among hemodialysis patients with functional iron deficiency anemia have shown conflicting results. We conducted a meta-analysis to assess the efficacy and safety of intravenous iron in this subset of patients.

METHODS

We searched MEDLINE (through December 2012), the Cochrane Central Register of Controlled Trials and ClinicalTrials.gov for single-arm studies and randomized controlled trials (RCT) that examined the effect of intravenous iron for functional iron deficiency anemia in hemodialysis patients on anemia parameters and markers of oxidative stress and inflammation. Studies of absolute iron deficiency were excluded. Random-effect model meta-analyses were used to compute changes in outcomes of interest.

RESULTS

We identified 34 studies (2,658 patients), representing 24 single-arm studies, and 10 parallel-arm RCT. In the analyses of the study arms, intravenous iron therapy resulted in a significant increase in hemoglobin, serum ferritin, transferrin saturation rate, serum iron, reticulocyte hemoglobin content as well as a significant decrease in the percentage of hypochromic erythrocytes and erythropoietin dose. There were significant increases in plasma malonyldialdehyde level and thiobarbituric acid-reactive substances, and a decrease in neutrophil respiratory burst. The analyses of the RCT revealed less robust net changes in these parameters, and there was no increased risk of adverse events including infections, cardiac events and mortality.

CONCLUSIONS

Intravenous iron therapy for functional iron deficiency anemia in hemodialysis patients improves anemia parameters but exerts some effects on markers of oxidative stress that are of unclear clinical significance. The long-term safety and efficacy of this treatment strategy requires further study.

Laboratory variables for assessing iron deficiency in REDS-II Iron Status Evaluation (RISE) blood donors

BACKGROUND

Iron deficiency is common in regular blood donors. We evaluated the diagnostic sensitivity and specificity of red blood cell (RBC) hematology analyzer indices to assess iron status as a part of donor management.

STUDY DESIGN AND METHODS

A total of 1659 male and female donors from the Retrovirus Epidemiology Donor Study-II (REDS-II) Donor Iron Status Evaluation (RISE) study who were either first-time/reactivated (FT/RA; no donations for 2 years) or frequent donors were recruited into a longitudinal study of regular donation of RBCs. Of these, 1002 donors returned 15 to 24 months later for a final assessment. Absent iron stores (AIS) was defined as plasma ferritin level of less than 12 μg/L. Logarithm of the ratio of soluble transferrin receptor to ferritin of at least 2.07 (≥97.5% in FT/RA males) was used to define iron-deficient erythropoiesis (IDE). Receiver operating characteristics analysis was performed to assess selected RBC indices (e.g., percentage of hypochromic mature RBCs, proportion of hypochromic mature RBCs [HYPOm], and hemoglobin [Hb] content of reticulocytes [CHr]) in identifying AIS and IDE.

RESULTS

HYPOm and CHr detected IDE with comparable sensitivity, 72% versus 69%, but differed in specificity: HYPOm 68% and CHr 53%. For detecting AIS, sensitivity was improved to 85% for HYPOm and 81% for CHr but specificity was reduced for both. Venous Hb had high specificity but poor sensitivity for IDE and AIS. A plasma ferritin level of less than 26.7 μg/L was a good surrogate for assessing IDE.

CONCLUSION

RBC indices correlate with AIS and IDE and are more informative than Hb measurement, but lack sufficient sensitivity and specificity to be used as diagnostic tools in blood donors at risk for iron deficiency.

Biomarkers of hypochromia: the contemporary assessment of iron status and erythropoiesis

Iron status is the result of the balance between the rate of erythropoiesis and the amount of the iron stores. Direct consequence of an imbalance between the erythroid marrow iron requirements and the actual supply is a reduction of red cell hemoglobin content, which causes hypochromic mature red cells and reticulocytes. The diagnosis of iron deficiency is particularly challenging in patients with acute or chronic inflammatory conditions because most of the biochemical markers for iron metabolism (serum ferritin and transferrin ) are affected by acute phase reaction. For these reasons, interest has been generated in the use of erythrocyte and reticulocyte parameters, available on the modern hematology analyzers. Reported during blood analysis routinely performed on the instrument, these parameters can assist in early detection of clinical conditions (iron deficiency, absolute, or functional; ineffective erythropoiesis, including iron restricted or thalassemia), without additional cost. Technological progress has meant that in recent years modern analyzers report new parameters that provide further information from the traditional count. Nevertheless these new parameters are exclusive of each manufacturer, and they are patented. This is an update of these new laboratory test biomarkers of hypochromia reported by different manufactures, their meaning, and clinical utility on daily practice.

Is analysis of the reticulocyte haemoglobin equivalent a useful test for the diagnosis of iron deficiency anaemia in geriatric patients?

BACKGROUND

Iron deficiency anaemia (IDA) and anaemia of chronic disease (ACD) are common in elderly patients but there are no standard diagnostic criteria. The reticulocyte haemoglobin equivalent (Ret-He) is routinely measured by modern automated blood analysers and is an early indicator of iron deficiency. The aim of this study was to investigate whether the Ret-He level as calculated by the Sysmex XE-5000 automated blood analyser is a useful parameter for the diagnosis of IDA in a geriatric hospitalized population.

METHODS

In a prospective study, blood samples were collected in 26 geriatric patients with IDA and 111 patients with ACD diagnosed according to generally accepted laboratory and clinical criteria. A blood count including Ret-He, mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC) and standard iron parameters was performed in each patient.

RESULTS

Haemoglobin, Ret-He, MCV, MCH and MCHC levels were all significantly lower in IDA as compared to ACD patients. However, the area under the curve (AUC) was greater for MCH (0.87, 95% CI 0.78-0.95) and MCHC (0.86, 95% CI 0.76-0.96) then for Ret-He (0.828, 95% CI 0.73-0.93) and MCV (0.80, 95% CI 0.68-0.91). A Ret-He cut-off value of 26 pg had a sensitivity and specificity based on its optimal combination of 85% and 69% respectively.

CONCLUSION

Analysis of Ret-He does not perform better than the classical red cell indices such as MCH and MCHC in differentiating IDA and ACD in geriatric patients.

Reference intervals of extended erythrocyte and reticulocyte parameters

Optical analysis of erythrocytes can provide information on the hemoglobin concentration and content of reticulocytes and mature erythrocytes. Such parameters have proven clinical utility in anemia diagnosis and therapy monitoring. For interpretation, reliable reference ranges are needed. The aim of this study was to establish reference intervals for extended erythrocyte and reticulocyte parameters as measured with the Abbott CELL-DYN Sapphire hematology analyzer. Secondary aims were to study sample stability and to investigate gender- and age dependency of the reference ranges.

Extended RBC parameters were measured in routine samples of a primary health care laboratory. The study cohort included 8161 samples of unique individuals, which were analyzed using Bhattacharya statistics. As a comparison, reference intervals were calculated in a subset of individuals without iron depletion.

The majority of erythrocyte and reticulocyte para\xadmeters were normally distributed, allowing calculation of reference intervals. Only for hypo- and hyperchromic erythrocytes non-parametric statistics had to be used. The reference range for mean cellular hemoglobin content of reticulocytes (MCHr) was 28.5–34.5 pg (1.77–2.14 fmol) in the entire study group and 26.0–35.1 pg (1.60–2.17 fmol) in the non iron-depleted subgroup. No differences between sexes were found. Most parameters showed significant age effects in children and adolescents.

Reference intervals have been established for extended RBC and reticulocyte parameters for the CELL-DYN Sapphire. Gender effects could not be demonstrated and age effects were of limited size, except for individuals younger than 18 years. Extended RBC parameters are stable for at least 6 h after blood collection.

New erythrocyte and reticulocyte parameters on CELL-DYN Sapphire: analytical and preanalytical aspects

INTRODUCTION

Extended RBC and reticulocyte parameters are useful in diagnosing functional iron deficiency and various other clinical conditions. The newest software of the CELL-DYN Sapphire measures extended RBC and reticulocyte parameters. The aims of the present communication were to assess the analytical aspects of these parameters compared with the Siemens Advia 120 analyzer, to study the effect of sample aging and to briefly explore their clinical usefulness in patients with anemia.

METHODS

Blood samples were obtained from the routine workload of two hospital laboratories and were run on Siemens Advia and Abbott CELL-DYN Sapphire analyzers in parallel. Data analysis was performed using standard statistics.

RESULTS

In total, 1416 patient samples were analyzed. There was close correlation in microcytic and macrocytic RBC (r(2) > 0.97) with small bias. The hypo- and hyperchromic RBC showed reasonable correlations, Advia 120 giving higher values. Reticulocyte MCV showed acceptable agreement, with significant proportional bias (Advia 8-9% higher). CELL-DYN Sapphire MCHr correlated rather well with Advia CHr (r(2) > 0.91) with significant absolute bias. Remarkably, the correlation data differed significantly between the two laboratories. It was found that aging of EDTA samples had significant effect on most of the RBC parameters.

CONCLUSIONS

The new RBC parameters of CELL-DYN Sapphire generally correlated well with those of Advia 120, although significant systematic differences were present, particularly in reticulocyte MCH and MCV. These differences necessitate instrument-specific reference ranges and clinical decision values. To minimize preanalytical effects, these parameters should be measured in fresh blood samples.

Low hemoglobin density potential marker of iron availability

INTRODUCTION

Low hemoglobin density (LHD%) is a new parameter provided by Beckman-Coulter derived from the mean cell hemoglobin concentration, using the mathematical sigmoid transformation LHD% = 100×√(1-(1/(1 + e(1.8(30-MCHC)))). This study investigated the reliability of LHD% for the assessment of iron status in the presence of inflammation.

METHODS

Healthy subjects (n = 90) and patients with iron deficiency (IDA, n = 110), chronic kidney disease (CKD, n = 65) and anemia of chronic disease (ACD, n = 85; 24 were iron deficient and 61 were iron sufficient) were analyzed on a LH 780 analyzer (Beckman Coulter Inc., Miami, FL, USA). Independent samples U test and receiver operating characteristic (ROC) curve analysis were applied. To determine the concordance between LHD% and soluble transferrin receptor (sTrR) Cohen's κ index was calculated.

RESULTS

LHD % values showed no statistical difference in patients with IDA and patients with ACD accompanied with IDA (P = 0.6427); LHD% values in these patients were significantly different (P < 0.0001) compared with the iron-sufficient patients with ACD. ROC analysis for LHD% in the detection of iron deficiency showed the following: area under curve 0.903; cut off 5.5%, sensitivity 88.6%, specificity 76.9%; κ index, 0.65.

CONCLUSION

LHD% is a reliable parameter for the detection of iron deficiency in patients with anemia in the presence of inflammation.