Interferents of Automated Reticulocyte Analysis Integrated with Relevant Clinical Cases.

BACKGROUND: Reticulocyte count (RET) has been used for many years to estimate the erythropoietic activity of the bone marrow. Fully automated methods not only provide enhanced precision and accuracy, but also enable reliable measurements of mRNA content and cellular indices. However, problems still exist, such as interference. The aim of the present study was to investigate the interferents of Sysmex XN 9000 reticulocyte analysis and ensure the accuracy of the results. METHODS: We collected a total of 510 specimens from normal control patients and patients with various diseases including anemias, leukemias, infectious diseases, immune diseases, kidney disease, etc. Correlation of the agreement for reticulocytes between the new methylene blue (NMB) visual microscopy method and automated reticulocyte counting was evaluated by paired sample method according to the CLSI-ICSH document H44-A2-Methods for Reticulocyte Count. Blood smear microscopic examination was carried out on the disturbed samples, and the interferents were analyzed with the medical history, flagging algorithms, the warning information, and the microscopic examination. RESULTS: A total of 44 (8.6%) cases exhibited interference. The main interferents of spuriously high reticulocyte count were caused by parasites, such as malaria, as well as suspicious autofluorescence due to drugs, while the main interferents of spuriously low reticulocyte count were caused by RBC fragments. CONCLUSIONS: Detection of potential interferences may be accomplished through alarm information and flagging algorithms incorporated into the instrument and by examination of a blood film to ensure absence of relevant interferences.

Diagnostic performances of manual and automated reticulocyte parameters in anaemic cats.

Objectives The objective of this study was to evaluate the diagnostic performances of manual and instrumental measurement of reticulocyte percentage (Ret%), reticulocyte number (Ret#) and reticulocyte production index (RPI) to differentiate regenerative anaemia (RA) from non-regenerative anaemia (NRA) in cats. Methods Data from 106 blood samples from anaemic cats with manual counts (n = 74; 68 NRA, six RA) or instrumental counts of reticulocytes (n = 32; 25 NRA, seven RA) collected between 1995 and 2013 were retrospectively analysed. Sensitivity, specificity and positive likelihood ratio (LR+) were calculated using either cut-offs reported in the literature or cut-offs determined from receiver operating characteristic (ROC) curves. Results All the reticulocyte parameters were significantly higher in cats with RA than in cats with NRA. All the ROC curves were significantly different ( P <0.001) from the line of no discrimination, without significant differences between the three parameters. Using the cut-offs published in literature, the Ret% (cut-off: 0.5%) was sensitive (100%) but not specific (<75%), the RPI (cut-off: 1.0) was specific (>92%) but not sensitive (<15%), and the Ret# (cut-off: 50 × 10³/µl) had a sensitivity and specificity >80% and the highest LR+ (manual count: 14; instrumental count: 6). For all the parameters, sensitivity and specificity approached 100% using the cut-offs determined by the ROC curves. These cut-offs were higher than those reported in the literature for Ret% (manual: 1.70%; instrumental: 3.06%), lower for RPI (manual: 0.39; instrumental: 0.59) and variably different, depending on the method (manual: 41 × 10³/µl; instrumental: 57 × 10³/µl), for Ret#. Using these cut-offs, the RPI had the highest LR+ (manual: 22.7; instrumental: 12.5). Conclusions and relevance This study indicated that all the reticulocyte parameters may confirm regeneration when the pretest probability is high, while when this probability is moderate, RA should be identified using the RPI providing that cut-offs <1.0 are used.

Post-transfusion changes in serum hepcidin and iron parameters in preterm infants.

BACKGROUND: Packed red blood cell transfusion is common in preterm neonates. Hepcidin acts as a negative feedback iron regulator. Iron parameters such as immature reticulocyte fraction (IRF) and high-light-scatter reticulocytes (HLR) are used to clarify iron metabolism. Very little is known about the regulation of hepcidin in preterm infants because most reports have evaluated prohepcidin. The aim of this study was therefore to evaluate serum hepcidin and establish hematological parameters in preterm infants after transfusion. METHODS: The subjects consisted of 19 newborns (10 boys) with mean gestational age 29.1 ± 2.0 weeks, who had been transfused at the chronological age of 44.84 ± 19.61 days. Blood sample was collected before the transfusion and thereafter at 5 days and at 1 month. Serum hepcidin and other iron parameters were evaluated. RESULTS: Mean serum hepcidin before and 5 days after transfusion was significantly different (5.5 ± 5.1 vs 10 ± 7.9 ng/mL respectively, P = 0.005). IRF and % HLR were also decreased significantly, 5 days after transfusion (0.4 ± 0.2 vs 0.2 ± 0.1, P = 0.009; 1.4 ± 1.5% vs 0.5 ± 0.4%, P = 0.012, respectively). Changes in hepcidin 5 days after transfusion were correlated significantly with changes in mean corpuscular hemoglobin (ß, 0.13; SE, 0.05; P = 0.017), total iron binding capacity (ß, 3.74; SE, 1.56; P = 0.016) and transferrin (ß, 2.9, SE, 1.4; P = 0.039). CONCLUSIONS: Serum hepcidin concentration, along with IRF and HLR, are potentially useful in estimating pre- and post-transfusion iron status. Larger studies are needed to evaluate the sensitivity and specificity of hepcidin compared with ordinary iron parameters in premature infants.

Reticulocyte count and extended reticulocyte parameters by Mindray BC-6800: Reference intervals and comparison with Sysmex XE-5000.

INTRODUCTION: In this study, analytic performance (imprecision, carryover, time stability) and diagnostic efficiency of Mindray BC-6800 analyzer to quantify reticulocytes and extended reticulocyte parameters was evaluated. Moreover, reference intervals on adult population were determined. Results were compared with those obtained by Sysmex XE-5000 analyzer. METHODS: One hundred and eighty-four healthy adults of both sexes, and 368 subjects affected by various pathologic conditions (nutritional anemias before and after treatment, hemolytic and posthemorragic anemias, acute and chronic inflammations, malignancy under therapy, and beta thalassemia trait) were selected. RESULTS: Reference intervals were as follows: reticulocytes (×109 /L): 23.2-93.2; immature reticulocyte fraction: 0.015-0.14; mean reticulocyte hemoglobin equivalent (RHE) (pg): 30.9-35.7; mean reticulocyte volume (fL): 97.8-118. Imprecision on reticulocyte count at all concentrations was close to analytic goal based on within-subject biological variation. Carryover (2.3%) was negligible, and time-stability was excellent up to 8 hours. CONCLUSION: When compared with XE-5000, BC-6800 shows a good overall correlation on counting despite evidence of difference in the upper limit of reference intervals (93.2 vs 101.3). Comparison of diagnostic efficiency of extended parameters shows a good total agreement of RHE (91.6%).

El conteo automático de reticulocitos: una herramienta de uso diagnóstico, clínico e investigativo / Automated reticulocyte count: a tool for diagnostic, clinical and research use

Se revisan los antecedentes históricos del conteo de reticulocitos como determinación indispensable en el laboratorio de hematología para la evaluación de la actividad eritropoyética durante la clasificación, diagnóstico y monitoreo de la respuesta terapéutica en distintos trastornos y situaciones clínicas, principalmente en casos de anemias. Se describe el tránsito del tradicional método de conteo de reticulocitos manual al método automatizado y la integración de los parámetros reticulocitarios al hemograma automatizado actual; además, se analizan las desventajas del método de recuento manual y las ventajas del método automatizado, así como los principios de detección en que se basa el conteo electrónico de reticulocitos. Con relación a los parámetros reticulocitarios, se describe su medición, cálculo y unidades de medida; también se resalta la importancia de la fracción de reticulocitos inmaduros y del contenido de hemoglobina reticulocitaria como variables de mayor uso clínico e investigativo en la evaluación de la respuesta medular ante diversos trastornos clínicos y protocolos terapéuticos. Por último, se alude a la necesidad del conocimiento y empleo de las variables reticulocitarias en la práctica clínica de rutina por parte de los clínicos y especialistas en hematología.

The historical background of reticulocyte count is reviewed as an essential determination in the laboratory of hematology for the evaluation of erythropoietic activity during classification, diagnosis and monitoring of therapeutic response of different conditions and clinical situations are also reviewed, especially in anemia The transition from traditional manual reticulocyte counting method to automated method and integration of the reticulocyte parameters to current automated complete blood count are described. The disadvantages of manual method and the advantages of automated methods are cited, as well as detection principles in which electronic reticulocyte count is based. Regarding reticulocyte parameters, measurement, calculation and units are described. The importance of immature reticulocyte fraction and reticulocyte hemoglobin content as variables most clinical and research use in evaluating bone marrow response to various clinical disorders and therapeutic protocols are highlighted. Finally, the need for knowledge and use of reticulocyte variables in routine clinical practice by clinicians and hematologist is referred.

Automated reticulocyte parameters for hereditary spherocytosis screening.

The laboratory diagnosis of hereditary spherocytosis (HS) is based on several screening and confirmatory tests; our algorithm includes clinical features, red blood cell morphology analysis and cryohaemolysis test, and, in case of positive screening, sodium dodecyl sulphate polyacrylamide gel electrophoresis as a diagnostic test. Using the UniCel DxH800 (Beckman Coulter) haematology analyser, we investigated automated reticulocyte parameters as HS screening tool, i.e. mean reticulocyte volume (MRV), immature reticulocyte fraction (IRF) and mean sphered cell volume (MSCV). A total of 410 samples were screened. Gel electrophoresis was applied to 159 samples that were positive for the screening tests. A total of 48 patients were diagnosed as HS, and seven were diagnosed as acquired autoimmune haemolytic anaemia (AIHA). Some other 31 anaemic conditions were also studied. From the receiver operating characteristic (ROC) curve analysis, both delta (mean cell volume (MCV)-MSCV) and MRV presented an area under the curve (AUC) of 0.98. At the diagnostic cut-off of 100 % sensitivity, MRV showed the best specificity of 88 % and a positive likelihood ratio of 8.7. The parameters IRF, MRV and MSCV discriminated HS not only from controls and other tested pathologies but also from AIHA contrary to the cryohaemolysis test. In conclusion, automated reticulocyte parameters might be helpful for haemolytic anaemia diagnostic orientation even for general laboratories. In combination with cryohaemolysis, they ensure an effective and time-saving screening for HS for more specialised laboratories.

Contagem de reticulócitos por citometria de fluxo utilizando acridine orange: validação de um novo protocolo / Flow cytometry reticulocyte counting using acridine orange: validation of a new protocol

Introduction: Currently, the reticulocyte counting is a challenge for clinical laboratories in Brazil, mainly for the ordinary ones, which still use the manual method. This method has some limitations, since it consists of a laborious method, time consuming, with low accuracy. Objectives: This study has developed and evaluated the performance of a New Laboratory Protocol for flow cytometry (FC) reticulocytes counting using acridine orange (AO) as dye, aiming to standardize a more precise, easy, fast implementation, and low cost protocol. After standardization of the New Protocol (FC/AO), it was compared with the manual method. The results were analyzed according to the recommendations of the National Committee for Clinical Laboratory Standards (NCCLS), now known as Clinical and Laboratory Standards Institute (CLSI), to evaluate the interchangeability of methods in linear regression analysis and paired t test, besides other quality control tests. Conclusion: Based on these results concerning to the correlation between the methods and the tests related to quality control, we can admit that FC/AO for reticulocyte counting shows undeniable advantages when compared to the preexisting manual method...

Introdução: Atualmente, a contagem de reticulócitos representa um desafio para os laboratórios clínicos no Brasil, principalmente os de pequeno e médio porte, nos quais ainda se utiliza o método manual. Este método apresenta algumas limitações, classificando-se como tedioso, demorado e de baixa precisão. Objetivos: O presente estudo desenvolveu e avaliou o desempenho de um novo protocolo laboratorial para contagem de reticulócitos por citometria de fluxo (CF) utilizando acridine orange (AO) como corante, visando padronizar um protocolo preciso, de fácil e rápida execução e custo acessível. Após a padronização do novo protocolo desenvolvido (CF/AO), fez-se a comparação com o método manual. Os resultados foram analisados de acordo com recomendações do National Committee for Clinical Laboratory Standards (NCCLS), atualmente Clinical and Laboratory Standards Institute (CLSI), para avaliar a intercambialidade entre os métodos, por meio da análise de regressão linear e teste t pareado, além de outros testes de controle de qualidade. Conclusão: Diante dos resultados obtidos referentes à correlação entre os métodos e os testes voltados ao controle de qualidade, pode-se admitir que o CF/AO estabelecido para contagem de reticulócitos possui vantagens inegáveis quando comparado com o método manual...

Reticulocyte dynamic and hemoglobin variability in hemodialysis patients treated with Darbepoetin alfa and C.E.R.A.: a randomized controlled trial.

BACKGROUND: In a simulation based on a pharmacokinetic model we demonstrated that increasing the erythropoiesis stimulating agents (ESAs) half-life or shortening their administration interval decreases hemoglobin variability. The benefit of reducing the administration interval was however lessened by the variability induced by more frequent dosage adjustments. The purpose of this study was to analyze the reticulocyte and hemoglobin kinetics and variability under different ESAs and administration intervals in a collective of chronic hemodialysis patients. METHODS: The study was designed as an open-label, randomized, four-period cross-over investigation, including 30 patients under chronic hemodialysis at the regional hospital of Locarno (Switzerland) in February 2010 and lasting 2 years. Four subcutaneous treatment strategies (C.E.R.A. every 4 weeks Q4W and every 2 weeks Q2W, Darbepoetin alfa Q4W and Q2W) were compared with each other. The mean square successive difference of hemoglobin, reticulocyte count and ESAs dose was used to quantify variability. We distinguished a short- and a long-term variability based respectively on the weekly and monthly successive difference. RESULTS: No difference was found in the mean values of biological parameters (hemoglobin, reticulocytes, and ferritin) between the 4 strategies. ESAs type did not affect hemoglobin and reticulocyte variability, but C.E.R.A induced a more sustained reticulocytes response over time and increased the risk of hemoglobin overshooting (OR 2.7, p = 0.01). Shortening the administration interval lessened the amplitude of reticulocyte count fluctuations but resulted in more frequent ESAs dose adjustments and in amplified reticulocyte and hemoglobin variability. Q2W administration interval was however more favorable in terms of ESAs dose, allowing a 38% C.E.R.A. dose reduction, and no increase of Darbepoetin alfa. CONCLUSIONS: The reticulocyte dynamic was a more sensitive marker of time instability of the hemoglobin response under ESAs therapy. The ESAs administration interval had a greater impact on hemoglobin variability than the ESAs type. The more protracted reticulocyte response induced by C.E.R.A. could explain both, the observed higher risk of overshoot and the significant increase in efficacy when shortening its administration interval. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01666301.

Highly fluorescent reticulocyte count is the early predictor of haematopoietic recovery on remission induction phase.

Highly fluorescent reticulocyte count a new routine parameter in the hematology analyzer can give the idea of the earliest morphologic change of bone marrow recovery before other test become positive after chemotherapy. A prospective study was carried out in the Department of Clinical Pathology in collaboration with Paediatric Haematology and Oncology, Bangabandhu Sheikh Mujib Medical University (BSMMU) during a period of one year starting from October 2009 to September 2010 to evaluate the bone marrow recovery in children with acute lymphoblastic leukemia (ALL) by automated reticulocyte analysis. Total fifty patients were enrolled in this study on remission induction phase. All patients were between 8 months to 15 years age range with a mean age of 5.5±3.2. At the end of the study highly fluroscent reticulocyte count recovery occurred earlier than the current practice of absolute neutrophil count (ANC) recovery.

Anticlastogenic effect of Eryngium foetidum L. assessed by erythrocyte micronucleus assay.

The aim of this study was to investigate the anticlastogenicity as well as the clastogenicity of Eryngium foetidum leaf (EF) using the in vivo mouse peripheral blood erythrocyte micronucleus assay. Eighty ICR male mice were fed AIN-76 diet supplemented with ground freeze-dried EF at 0.0%, 0.8%, 1.6% and 3.2% for 2 weeks prior to the administration of both direct-acting, mitomycin C (MMC), and indirect-acting, 7, 12-dimethylbenz(a) anthracene (DMBA) clastogens. Peripheral blood samples were collected from mice just before administration of clastogen and at 24 and 48 h thereafter for MMC. Blood samples were collected at the same times and after 72 h for DMBA. Then, reticulocytes in blood samples were counted using fluorescent microscopy. The results indicated that EF had no clastogenic effect in mice. All doses of diets supplemented with EF decreased the number of micronucleated peripheral reticulocytes in all the MMC-treated groups in a dose dependent manner, but significant reduction was found only at 1.6% and 3.2% EF in the DMBA-treated groups. It can be concluded that EF has no clastogenicity, but possesses anticlastogenic potential against both direct- and indirect-acting types of clastogen in mice.

Evaluation of derived Coulter red blood cell parameters for the assessment of iron deficiency in adults with congenital heart disease.

INTRODUCTION: The aim of our study was to evaluate derived red blood cell parameters in determining the presence of iron depletion and iron-deficient erythropoiesis, as states that precede iron deficiency anemia, in adults with congenital heart disease. METHODS: Eighty-eight adults who were diagnosed with congenital heart disease were divided into two groups (cyanotic and acyanotic). In both groups, congenital heart disease patients were then divided into three subgroups: with iron depletion, with iron-deficient erythropoiesis, and a control group. The following parameters were measured: complete blood count, reticulocytes, ferritin, soluble transferrin receptor, haptoglobin, lactate dehydrogenase, and calculated parameters: low hemoglobin density (LHD), red cell size factor (RSF), and microcytic anemia factor (MAF). RESULTS: Discriminant analysis indicated statistically significant differences in the first discriminant function: Function 1 - body iron, LHD, MAF, sTfR, and RSF (P < 0.001) in patients with acyanotic congenital heart disease and significant differences in both discriminant functions in patients with cyanotic congenital heart disease: Function 1 - body iron, soluble transferrin receptor, LHD, RSF, MAF, lactate dehydrogenase, and haptoglobin (P = 0.008) and Function 2 - reticulocytes (#), immature reticulocyte fraction and reticulocytes (%) (P = 0.049). CONCLUSIONS: Beside parameters that describe iron metabolism dynamics (body iron and soluble transferrin receptor), LHD, indicator of hypochromia, have the highest potential to differentiate and classify iron deficiency in patients with congenital heart disease.

Automated reticulocyte counting: state of the art and clinical applications in the evaluation of erythropoiesis.

The reticulocyte count reflects the erythropoietic activity of the bone marrow and is thus useful in both the diagnosis of anemias and in monitoring bone marrow response to therapy. Starting in the mid-1990s, automated flow-cytometric analysis has replaced traditional microscopic quantitation of reticulocytes. Reticulocyte analysis now includes measurements mRNA content and the maturity of reticulocytes, cell volume, hemoglobin concentration and content. The immature reticulocyte fraction is a reliable early predictor of hematopoietic engraftment following allogeneic stem cell transplantation, while the reticulocyte hemoglobin content provides an indirect measure of the functional iron available for new red blood cell production over the previous 3-4 days. Especially in anemic newborns, reticulocyte analysis is useful to help clinicians follow erythropoietic changes, to monitor response to recombinant human erythropoietin therapy, to gauge transfusion needs, and to evaluate jaundice. Despite improved accuracy and precision, significant problems still persist in maintaining adequate levels of precision and comparability across different laboratories. In the absence of better laboratory standardization, having a single reference range for the parameters provided by flow-cytometric studies of reticulocytes remains problematic.

[Assessment of an immature platelet fraction (IFP%) in the diagnosis of thrombocytopenia]. / Valeur du pourcentage de plaquettes réticulées dans le diagnostic étiologique d'une thrombopénie.

Reticulated platelets are young platelets containing mRNA. They reflect the rate of thrombopoesis. The aim of this study was to evaluate the reliability of the percentage of reticulated platelets (IPF%) as a diagnostic test for thrombocytopenia pathogenesis. IPF% was measured using XE 2100 Sysmex. An IPF% reference range in 52 healthy individuals was established as 1-4.5% with a median 2.2%. In all the 13 patients with idiopathic thrombocytopenic purpura IPF% was increased (median 11.8, range 5.3-54.3%). Only 7 out of 18 patients with disseminated intravascular coagulation had high IPF% (median 5.4%, range 2.9-14.1%). Surprisingly, IPF% was increased in 17 out of 22 patients with acute leukaemia (median 9.7%, range 0.9-41.9%). In CIVD, IPF% values correlated with the severity of the illness. Increased values in acute leukaemia could not be explained by non specific staining but by delayed maturation of reticulated platelets. A high IPF% does not substantiate hyperdestructive thrombocytopenia but a diagnosis of idiopathic thrombocytopenic purpura should be questioned if IPF% is not raised.

Age, beta thalassaemia trait, and iron-deficient anaemia significantly affect reticulocyte indices in pre-school children.

BACKGROUND: Reticulocyte indices are easy to obtain, low cost parameters and have gained interest in the field of diagnosing anaemias of childhood. METHODS: We assessed distribution, age and gender variation, relation to indices of iron metabolism and diagnostic performance of reticulocyte haemoglobin content (CHr), percentage of microcytic reticulocytes (micro_r), percentage of hypochromic reticulocytes (hypo_r), and percentage of reticulocytes with low CHr (low_CHr) in 386 pre-school children classified in four groups: healthy, iron deficiency (ID), iron deficiency anaemia (IDA), and beta-thalassaemia carriers (beta-thal). RESULTS: Age had a positive effect in CHr (Spearman's rho = 0.21) and a negative effect in hypo_r (Spearman's rho = -0.2) in healthy children. CHr and low_CHr were related to ferritin in the IDA group (Spearman's rho 0.55 and -0.53, respectively). In the beta-thal group, HbA(2) is strongly related to all reticulocyte indices. micro_r and CHr performed best in discriminating between IDA and beta-thal heterozygosity (ROC analysis, area under the curve (AUC): 0.76 and 0.74, respectively). CHr achieved the best AUC (0.58) in identifying ID among children without anaemia. CONCLUSION: Age, IDA and beta-thal significantly affect reticulocyte indices. CHr and micro_r may have a role as screening tools in discriminating between IDA and beta-thal heterozygosity.

Analysis of manual reticulocyte counts in the clinical laboratories of Ponta-Grossa and Campos Gerais, PR, Brazil

Reticulocyte counts are widely used in laboratories to evaluate bone marrow erythropoietic activity and have great diagnostic and prognostic importance in the treatment of anemias. Reticulocytes are supravitally stained with new methylene blue or brilliant cresyl blue, which highlight the characteristic aspect of the reticulum visible by light microscopy. Known criteria were observed for good manual reticulocyte counting with special attention being paid to the preparation of reticulocyte slides, to counting fields without overlapping cells, and to the number of evaluated cells. The aim of this study was to evaluate the inter-observer variation and also to analyze the statistical error of manual reticulocyte counting. The Intraclass correlation coefficient (ICC) according to Bartko was used to evaluate the level of agreement among 12 laboratory technicians who evaluated the same 25 blood smears. The results of statistical analyses showed that the amount of random error, defined as (1-r2), varied from 4 percent to 60 percent among the technicians. Although imprecision occurred, the overall profiles were quite similar, and intraclass correlation coefficients indicated that the results obtained have clinical significance.

A contagem do reticulócitos é usada extensamente na rotina laboratorial para avaliar a atividade eritropoiética da medula óssea, e é de grande importância no diagnóstico e no prognóstico na terapia de anemias hemolíticas. São coradas com o azul de metileno novo e o azul cresil brilhante, o que conferem o aspecto característico de retículo quando observado ao microscópioótico. Critérios conhecidos foram observados para um bom desempenho da contagem manual de reticulócitos, principalmente, atenção especial nas películas do sangue durante a montagem das lâminas; contagem nos campos que não contém sobreposição celular; e também no número de células avaliadas. O objetivo deste estudo foi avaliar a variação interobservadores, analisar o erro estatístico da contagem manual dos reticulócitos, e demonstrar as limitações deste método. A análise de correlação intraclasses segundo Bartko [Psychol Rep 19:3,1966; 34:418,1974] foi usada para avaliar a concordância entre 12 observadores em um total de 25 lâminas do sangue, com contagens variadas de reticulócitos. Os resultados das análises estatísticas indicam que o erro casual, calculado como (1-r2) variou de 4 a 60 por cento entre os observadores. Embora ocorra imprecisão entre os observadores, o perfil geral entre eles é similar, e o coeficiente de correlação intraclasse indicou que os resultados obtidos são clinicamente úteis.

Automated blood cell counts: state of the art.

The CBC count and leukocyte differential count (LDC) are among the most frequently requested clinical laboratory tests. These analyses are highly automated, and the correct interpretation of results requires extensive knowledge of the analytic performance of the instruments and the clinical significance of the results they provide. In this review, we analyze the state of the art regarding traditional and new parameters with emphasis on clinical applications and analytic quality. The problems of some traditional parameters of the CBC count, such as platelet counts, some components of the LDC such as monocyte and basophil counts, and other commonly used indices such as red cell volume distribution width and platelet indices such as mean platelet volume and platelet distribution width are considered. The new parameters, evaluated from analytic and clinical viewpoints, are the available components of the extended differential count (hematopoietic progenitor cells, immature granulocytes, and erythroblasts), the immature reticulocyte fraction, the reticulocyte indices, the fragmented RBCs, and the immature platelet fraction.

[Clinical significance of reticulocyte maturation parameters in the differential diagnosis of macrocytic anemias].

BACKGROUND: Macrocytic anemias are commonly seen in clinical practice, and precise etiologic diagnosis is essential for proper management. We evaluated the clinical utility of reticulocyte maturation parameters in macrocytic anemias to discriminate among myelodysplastic syndrome (MDS), megaloblastic anemia (MA), and non-megaloblastic macrocytic anemia associated with chronic liver disease (MA-CLD). METHODS: Using an automated reticulocyte counter, we retrospectively analyzed and compared reticulocyte maturation parameters including immature reticulocyte fraction (IRF), mean reticulocyte volume (MRV), mean sphered cell volume (MSCV) of normal control (N=34), and patients diagnosed with MDS (N=31), MA (N=52), and MA-CLD (N=196). RESULTS: Macrocytic anemias from MA, MDS and MA-CLD showed higher values of reticulocyte maturation parameters including IRF, MRV and MSCV than normal control (P<0.01). MDS showed higher values of reticulocyte maturation parameters including IRF, MRV and MSCV than MA-CLD (P<0.01). IRF and MRV were significantly lower in MA-CLD than in both MA and MDS (P<0.01). MSCV was significantly higher in MDS than in MA (P<0.01). CONCLUSIONS: This study indicates that the measurement of reticulocyte maturation parameters may be a useful tool in the differential diagnosis of macrocytic anemia. The presence of high values of IRF (> or = 0.39), MRV (> or = 129.5 fL), and MSCV (> or = 102.3 fL) makes the diagnosis of MA-CLD unlikely and underlying MDS should be considered.

The immature reticulocyte fraction: a negative predictor of the harvesting of CD34 cells for autologous peripheral blood stem cell transplantation.

The optimal time for the harvesting of peripheral blood stem cells following chemotherapy and growth factors for autologous transplantation is based on the CD34 cell count. In this study, 51 patients having 59 stem cell mobilizations were assessed for the timing of the harvest by a CD34 cell count and an immature reticulocyte fraction (IRF). Results from 272 preharvest tests showed that when the CD34 cells were not harvestable, defined as a CD34 cell count of < 15 cells/microl, the IRF was always < or = 0.2. A low IRF resulted in a negative predictive value of 1 for the harvesting of stem cells. The IRF is therefore a valuable negative predictor of the timing of autologous stem cell harvesting.

Reticulocyte-gated flow cytometric analysis of red blood cells in paroxysmal nocturnal hemoglobinuria.

Paroxysmal nocturnal hemoglobinuria (PNH) is a hematopoietic stem cell disorder characterized by the deficiency of glycosyl phosphatidylinositol (GPI)-anchored proteins in the affected blood cell membranes. Analysis of blood cells by flow cytometry is useful to identify the affected blood cells with PNH-specific phenotypes. Because PNH-affected red blood cells (RBC) have shortened life-spans in the circulation, ratios of PNH-affected populations analyzed by flow cytometry in whole RBC are lower than those in PNH-affected erythropoiesis. We developed a reticulocyte-gated 2-color flow cytometry of RBC and revealed that the percentages of PNH-affected, CD59--populations in reticulocytes were higher than in whole RBC in patients with PNH. A serial analysis of a patient with PNH who underwent peripheral blood stem cell transplantation confirmed the usefulness of this method to evaluate PNH-affected RBC populations with high sensitivity; ie, the presence of CD59- reticulocytes in the circulation could be a sensitive marker for PNH-affected erythropoiesis.