Analysis of red cell parameters on the Sysmex XE 2100 and ADVIA 120 in iron deficiency and in uraemic chronic disease

Evaluation of reticulocyte hemoglobin content (RETIC-HGB) for the diagnosis of iron-limited erythropoiesis in cats

BACKGROUND

Decreased reticulocyte hemoglobin content (CHr) (Siemens ADVIA 2120) reflects iron-limited erythropoiesis (ILE). RETIC-HGB (IDEXX ProCyte Dx) is a novel marker of ILE for veterinary use.

OBJECTIVES

We aimed to evaluate reference intervals (RIs) and the utility of RETIC-HGB and CHr in the diagnosis of feline ILE.

MATERIALS AND METHODS

RIs were established in 59 healthy cats. Intra-assay coefficients of variation (CVs) and correlations between RETIC-HGB and CHr were assessed. Two hundred and seventy-five cats were classified as having ILE or not based on low plasma iron or low transferrin saturation along with anemia and/or altered RBC indices. CHr, RETIC-HGB, and serum amyloid A (SAA) were compared between the groups. The sensitivity and specificity of RETIC-HGB and CHr to diagnose ILE were analyzed to determine the RI lower limits.

RESULTS

RIs for RETIC-HGB and CHr were 12.5-18.0 and 14.0-19.9 pg, respectively. The CV was 3% for both variables. RETIC-HGB and CHr were moderately correlated (r_s = 0.59) with a bias of -1.2 picograms (pgs). Twenty of the 275 cats were classified as having ILE. Compared with non-ILE cats, ILE cats had significantly lower median RETIC-HGB (14.3 vs 15.2 pg, P = .0046) and mean CHr (14.7 vs 16.5 pg, P < .0001) values and significantly increased median SAA (44.6 vs 2.3 µg/dl, P < .0001) values. Using the lower RI limits resulted in a low sensitivity and relatively high specificity to diagnose ILE in cats.

CONCLUSIONS

ILE was characterized by decreased CHr and RETIC-HGB; however, sensitivity was low. The moderate correlation between RETIC-HGB and CHr is likely due to species differences and different methodology.

Rapid Gardos Hereditary Xerocytosis Diagnosis in 8 Families Using Reticulocyte Indices

Gardos channelopathy (Gardos-HX) or type 2 stomatocytosis/xerocytosis is a hereditary hemolytic anemia due to mutations in the KCNN4 gene. It is rarer than inherited type 1 xerocytosis due to PIEZO1 mutations (Piezo1-HX) and its diagnosis is difficult given the absence of a specific clinical or biological phenotype. We report here that this diagnosis can be sped up using red blood cell (RBC) indices performed on an ADVIA 2120 (Siemens^®) analyzer, which measures reticulocyte mean corpuscular volume (rMCV) and mean corpuscular hemoglobin concentration (rMCHC). We studied reticulocyte indices in 3 new and 12 described patients (8 families) with Gardos-HX, 11 subjects presented the recurrent p.Arg352His mutation, 4 cases (two families) carried a private KCNN4 mutation. They were compared to 79 described patients (49 families) with Piezo1-HX. Surprisingly, in Gardos-HX cases, rMCV revealed to be smaller than MCV and rMCHC higher than MCHC, in contrast with normal or Piezo1-HX RBC. Consequently, ΔMCV (rMCV-MCV) was −0.9 ± 5 fL vs. 19.8 ± 3 fL (p < 0.001) in Gardos compared with Piezo1-HX and ΔMCHC (rMCHC-MCHC) was 18.7 ± 13 vs. −50 ± 8.7 g/L (p < 0.001). A threshold of 8.6 fL for ΔMCV and −5.5 g/L for ΔMCHC could discriminate between Gardos and Piezo1-HX with 100% sensitivity and specificity, regardless of age, mutation or splenectomy status. Consequently, we showed that reticulocytes indices are useful to suggest Gardos-HX on blood count results, allowing to rapidly target these patients for gene analysis. In addition, these parameters may prove useful as a ‘functional tool’ in interpreting new KCNN4 variants.

Treatment of Anemia of Chronic Disease with True Iron Deficiency in Pregnancy

Objective

We assess and compare the efficacy of anemia treatment in pregnant women with anemia of chronic disease with true iron deficiency and in women with iron deficiency anemia.

Study Design

Fifty patients with moderate anemia (hemoglobin 8.0–9.9 g/dl) and iron deficiency (ferritin < 15 μg/l) were treated in the Anemia Clinic at the Department of Obstetrics.

Results

All patients showed stimulation of erythropoiesis as evidenced by an increase in reticulocyte count at day eight of therapy and showed an increase in hemoglobin and hematocrit at the end of therapy (p < 0.001). The target hemoglobin (≥10.5 g/dl) was achieved in 45/50 women (90%). 12 patients showed anemia of chronic disease with true iron deficiency (12/50; 24%). Seven women (7/12; 59%) with anemia of chronic disease and iron deficiency responded well to anemia treatment. 50% of women with anemia of chronic disease and iron deficiency (3/6) responded well to intravenous iron, and 67% (4/6) responded well to the combination of intravenous iron and recombinant human erythropoietin.

Conclusion

Because of frequent true iron deficiency in pregnant women with anemia of chronic disease, anemia of chronic disease in pregnancy is often falsely diagnosed as iron deficiency anemia.

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.

Identification of a cross-reacting, monoclonal anti-human CD233 antibody for identification and sorting of rhesus macaque erythrocytes

Erythroid biology research involving rhesus macaques has been applied to several topics including malaria, hemoglobinopathy and gene therapy research. However, analyses of the rhesus red blood cells are limited by the inability to identify and sort those cells in research blood samples using flow cytometry. Here it is reported that the BRIC 6 hybridoma clone raised to the human erythroid surface molecule (referred to as CD233, Band 3, AE1, or SLC4A1) produces cross-reactive and erythroid-specific antibodies for flow cytometric detection and sorting of rhesus macaque erythrocytes.

Measurement of reticulocyte and red blood cell indices in the evaluation of anemia in inflammatory bowel disease

BACKGROUND

The commonest types of anemia in inflammatory bowel disease (IBD) are iron deficiency (IDA) and anemia of chronic disease. The differentiation between these two conditions is important for the management of the patient. The aim of this study was to investigate the usefulness of reticulocyte and red blood cell indices in the evaluation of anemia in IBD.

METHODS

One hundred IBD patients [49 ulcerative colitis (UC), 51 Crohn's disease (CD)] and 102 healthy controls were enrolled. Measurement of reticulocyte and red blood cell indices was performed using the Coulter LH780 Hematology Analyzer (Beckman Coulter). Additionally, serum levels of ferritin, transferrin saturation (Tsat) and soluble transferrin receptor (sTfR) were analyzed in all patients and controls.

RESULTS

The prevalence of anemia was 41.2% for UC and 42.9% for CD, whereas 30 IBD patients (30%) had IDA. Red cell Distribution Width (RDW), Red blood cell Size Factor (RSF), and Reticulocyte Distribution Width-Coefficient of Variation (RDWR-CV) were found significantly correlated with both Tsat and sTfR but not with ferritin levels. Patients with IDA had significantly higher RDW and RDWR-CV and significantly lower RSF levels compared with those without IDA. High values of RDW (sensitivity 93%, specificity 81%) and low values of RSF (sensitivity 83%, specificity 82%) were the best markers for the diagnosis of IDA. Both RDWR-CV and RDWR-SD were significantly correlated with disease activity and CRP levels.

CONCLUSION

RDW, RSF and RDWR, could be useful markers for the evaluation of anemia and disease activity in IBD.

The diagnostic accuracy of the percentage of hypochromic red blood cells (%HYPOm) and cellular hemoglobin in reticulocytes (CHr) in differentiating iron deficiency anemia and anemia of chronic diseases

BACKGROUND

The percentages of hypochromic red blood cells (%HYPOm) and cellular hemoglobin in reticulocytes (CHr) are suggested to be useful screening markers of iron deficiency. The aim of this study was to investigate the diagnostic accuracy of %HYPOm and CHr in differentiating iron deficiency anemia (IDA) and anemia of chronic disease (ACD).

METHODS

The retrospective population consisted of 58 IDA patients, 129 ACD patients and 63 controls, on whom bone marrow examination and blood count with %HYPOm and CHr had been performed. Receiver operating characteristic (ROC) analyses with area under the ROC curves (AUC) were used as statistical tests.

RESULTS

AUCs for differentiating the groups using %HYPOm were as follows: IDA vs. controls 0.99, ACD vs. controls 0.85 and IDA vs. ACD 0.88. AUCs for CHr in distinguishing the groups were as follows: IDA vs. controls 0.95, ACD vs. controls 0.65 and IDA vs. ACD 0.83.

CONCLUSIONS

IDA and ACD patients were efficiently differentiated by using %HYPOm and CHr. Additionally, %HYPOm was higher and CHr was lower in IDA patients and in ACD patients than in controls. Thus, %HYPOm is higher and CHr is lower not only in absolute iron deficiency, but also when iron availability for erythropoiesis is restricted.

Reticulocytes in sports medicine

Reticulocytes are the transitional cells from erythroblasts to mature erythrocytes. Reticulocytes are present in blood for a period of 1-4 days and can be recognized by staining with supravital dyes, such as new methylene blue, or fluorescent markers, which couple residual nucleic acid molecules, a hallmark of the immature forms of erythrocytes. Although reticulocytes could be counted through a microscope (there is a standard of International Committee for Standardisation in Haematology for manual counting), this method is reported to be time consuming, inaccurate and imprecise. The integration of the reticulocyte count in automated haematology systems allowed the widespread use of these parameters, although the lack of calibration material and different markers, technologies and software used in automated systems could engender discrepancies among data obtained from different analytical systems.The importance of reticulocytes in sports medicine derives from their sensitivity, the highest among haematology parameters, in identifying the bone marrow stimulation, especially when recombinant human erythropoietin is fraudulently used. Automated systems are also able to supply information on volume, density and the haemoglobin content of reticulocytes. Some of the related parameters are also used in algorithms for identifying abnormal stimulation of bone marrow as reticulocytes haematocrit. The pre-analytical variability of reticulocytes (transportation, storage, biological variability) should be taken into account in sports medicine also. Reticulocytes remain stable for almost 24 hours at 4 degrees C from blood drawing, they are affected by transportation, and biological variability is not high in general. It could be remarked, however, that the intra-individual variability is high when compared with other haematological parameters such as haemoglobin and haematocrit. The intervals of data reported in athletes are very similar to reference intervals characterizing the general population.The reticulocyte count shows some modifications after training and during the competition season. The variability induced by exercise cannot be overlooked since the so-called haematological passport, a personal athlete's document in which haemoglobin and other parameters are registered, may be introduced by sports federations. Exposure to naturally high altitude and 'living high-training low' programmes determined contentious results on reticulocytes. Simulated high altitude induced by intermittent hypobaric hypoxia does not modify reticulocytes, despite an increase in erythropoietin serum concentration. The variability among athletes competing in different sport disciplines is apparently limited. The knowledge of the behaviour of reticulocytes in training and competitions is crucial for defining their role in an antidoping control context. It is important for sport physicians and clinical pathologists to know the reticulocyte variability in the general population and in athletes, the pre-analytical warnings, the different methodologies for counting reticulocytes and the derived parameters automatically available, and, finally, the possible influence of training, competitions, type of sport and altitude.

Reticulocyte hemoglobin content

Under normal conditions, reticulocytes are the youngest erythrocytes released from the bone marrow into circulating blood. They mature for 1-3 days within the bone marrow and circulate for 1-2 days before becoming mature erythrocytes. Measurement of cellular hemoglobin concentration has long been reported by automated hematology analyzers as one of the red blood cell indices. The reticulocyte hemoglobin content (CHr or Ret-He) provides an indirect measure of the functional iron available for new red blood cell production over the previous 3-4 days. Measurement of reticulocyte hemoglobin content in peripheral blood samples is useful for diagnosis of iron deficiency in adults (Mast et al., Blood 2002;99:1489-1491) and children (Brugnara et al., JAMA 1999;281:2225-2230; Ullrich et al., JAMA 2005;294:924-930; Bakr and Sarette, Eur J Pediatr 2006;165:442-445). It provides an early measure of the response to iron therapy increasing within 2-4 days of the initiation of intravenous iron therapy (Brugnara et al., Blood 1994;83:3100-3101). Sequential measurements of reticulocyte hemoglobin content in patients with iron deficiency anemia provide a rapid means for assessing the erythropoietic response to iron replacement therapy (Brugnara et al., Blood 1994;83:3100-3101). It is also an early indicator or iron-restricted erythropoiesis in patients receiving erythropoietin therapy (Fishbane et al., Kidney Int 1997;52:217-222; Fishbane et al., Kidney Int 2001;60:2406-2411; Mittman et al., Am J Kidney Dis 1997;30:912-922; Tsuchiya et al., Clin Nephrol 2003;59:115-123; Chuang et al., Nephrol Dial Transplant 2003;18:370-377). Thus, reticulocyte hemoglobin content is a recent addition to an expanding list of biomarkers that can be used to differentiate iron deficiency from other causes of anemia.

Evaluation of reticulocyte parameters in iron deficiency, vitamin B(12) deficiency and beta-thalassemia minor patients

The aim of this study was to test the clinical utility of reticulocyte parameters in differential diagnosis in iron deficiency anemia (IDA), vitamin B(12) deficiency (B12) and beta-thalassemia minor (TM). We analyzed the percentage of reticulocyte, absolute reticulocyte count, mean content hemoglobin of reticulocyte (CHr), mean corpuscular volume of reticulocyte (MCVr), corpuscular hemoglobin concentration mean of reticulocyte (CHCMr), MCVr/MCV ratio, CHr/CH ratio and CHCMr/CHCM ratio in healthy donors (n = 34), iron deficiency (IDA) (n = 41), vitamin B(12) deficiency (B12) (n = 22), and TM (n = 34). This study demonstrates that the cutoff value of CHr was 25.7 as indicative of IDA (85.4% sensitivity, 97.1% specificity). CHr and MCVr may be useful for TM (cutoff value < or = 24.8 for CHr) and B12 (>102.1, cutoff value for MCVr), respectively. Sensitivity and specificity of these parameters were 90.9, 86.4% and 97.1, 82.4%, respectively. CHCMr is useful to differentiate IDA and TM from B12. While CHr was low value in microcytic groups (mean 21.8 +/- 3.3 for IDA, 21.0 +/- 2.9 for TM), it was high in B12 (mean 32.1 +/- 5.7). However, that of CHr/CH ratio was only significantly in IDA group compared with the control (P < 0.05, mean 0.98). Therefore, there are limitations regarding CHr and CHr/CH ratio differential diagnosis in microcytic and macrocytic groups. CHr, MCVr, and CHCMr are not sufficiently sensitive and specific to differentiate TM from IDA. We conclude that measurement of reticulocyte count and parameters may be a very useful implement in the diagnosis of IDA and TM.