Performance evaluation of BC-3200 hematology analyzer in a university hospital

The BC-3200 automated hematology analyzer was evaluated and compared with the Beckman-Coulter AcT (Ac.T diff 2) 3-part differential hematology analyzer. The BC-3200 was evaluated according to guidelines published by the International Committee for Standardization in Hematology (ICSH), Clinical and Laboratory Standards Institute (CLSI), and Department of Food and Drug Administration (FDA). The results demonstrated no background, minimal carryover (<0.5%), and excellent linearity for hemoglobin (Hb) level, white blood cell (WBC), red blood cell (RBC), and platelet (PLT) counts (>0.998). Precision was generally acceptable for all complete blood count (CBC) parameters; coefficients of variation (CVs) were within the manufacturer's claims and CVs of CBC parameters, including WBC, RBC and PLT counts, Hb and mean corpuscular volume, were <6%. Correlation between the BC-3200 and Ac.T diff 2 was excellent (r > 0.98) for all major CBC parameters (WBC, RBC, and PLT counts and Hb). We conclude that the overall performance of the BC-3200 is excellent and compares well with that of the Coulter Ac.T diff 2.     

成都地区健康人群血常规各参数参考值范围的调查

目的了解成都地区健康人群血常规各参数的正常参考值范围。方法 2007.10-2008.07在我院体检的不同年龄(儿童和成人)、不同性别(男女)、不同采血方式(全血和末梢血)的健康人群共22178人,于清晨空腹抽取静脉血2mL或手指末梢血40μL(儿童),应用深圳迈瑞公司BC-5500型全自动血液分析仪进行检测,检测项目包括:红细胞(RBC)、白细胞(WBC)、血红蛋白(Hb)、红细胞比容(HCT)、红细胞平均体积(MCV)、红细胞平均血红蛋白含量(MCH)、红细胞平均血红蛋白浓度(MCHC)、血小板(PLT)、红细胞体积分布宽度(RDW)、血小板体积分布宽度(PDW)、血小板平均体积(MPV)、血小板压积(PCT)、中性粒细胞百分率(NEU%)、淋巴细胞百分率(LYM%)、单核细胞百分率(MON%)、嗜酸性粒细胞百分率(EOS%)、嗜碱性粒细胞百分率(BAS%)等23项指标,剔除离群点后,采用SPSSl1.5软件进行统计分析。结果本调查的血常规各参数呈非正态分布,男性和女性参考值间有显著性差别(P<0.01),成人和儿童之间有显著性差别(P<0.01),儿童全血和末梢血之间有显著性差别(P<0.01),成都地...     

Sample stability for complete blood cell count using the Sysmex XN haematological analyser

Background

Sample stability is a crucial aspect for the quality of results of a haematology laboratory. This study was conducted to investigate the reliability of haematological testing using Sysmex XN in samples stored for up to 24 h at different temperatures.

Materials and methods

Haematological tests were performed on whole blood samples collected from 16 ostensibly healthy outpatients immediately after collection and 3 h, 6 h or 24 h afterwards, with triple aliquots kept at room temperature, 4 °C or 37 °C.

Results

No meaningful bias was observed after 3 h under different storage conditions, except for red blood cell distribution width (RDW) and platelet count (impedance technique, PLT-I) at 37 °C. After 6 h, meaningful bias was observed for mean corpuscular haemoglobin (MCH) and mean corpuscular volume (MCV) at room temperature, red blood cell (RBC) count, mean corpuscular haemoglobin concentration (MCHC), MCH, MCV and PLT-I at 4 °C, and RBC, RDW, MCHC, MCH and PLT-I at 37 °C. After 24 h, a meaningful bias was observed for MCHC, MCV, platelet count (fluorescent technique, PLT-F) and mean platelet volume (MPV) at room temperature, MCHC, MCV, PLT-I and MPV at 4 °C, and all parameters except RBC count and MPV at 37 °C.

Discussion

Great caution should be observed when analysing results of haematological tests conducted more than 3 h after sample collection.     

Immature platelet fraction in rheumatoid arthritis with interstitial lung disease

BackgroundPlatelets have an effect on the hemostatic defense of the lung. Immature platelet fractions (iPF) reflects the number of young platelets containing ribonucleic acid in the circulation and real-time production. Information about their roles in rheumatic diseases is limited and there are no studies on iPF in RA with interstitial lung disease (ILD). Our aim is to investigate the association between the iPF level and occurrence of ILD in RA and the correlation of iPF with disease activity in general or only in RA with ILD.MethodsThe study included 50 RA patients without ILD, 33 RA patients with ILD, and 30 healthy controls. Demographic data, Disease Activity Score 28 (DAS28), autoantibodies, and iPF were evaluated. ILD was diagnosed by using high-resolution computed tomography with clinical findings and chest X-ray. The samples were analyzed for complete blood count with platelet indices included, on Mindray BC-6800 hematology analyzer, Hamburg, Germany.ResultsiPF levels were higher in RA patients with ILD compared to healthy controls and RA patients without ILD. A weakly positive correlation between DAS28 with iPF was found in all RA patients. iPF levels were found as 2.85 to detect ILD with 66.7% sensitivity and 65% specificity.ConclusionsOur results showed that the iPF was detected higher in RA with ILD compared to RA without ILD. iPF, a routine cheap and easy test during hemogram, can provide important information in terms of disease activity and lung involvement in RA.     

Complete blood count parameters for healthy,small‐for‐gestational‐age,full‐term newborns

No previous study has investigated the full range of complete blood count (CBC) parameters in small‐for‐gestational‐age (SGA) newborns. The main aim of this study was to compare CBC and peripheral smear parameters in term, healthy SGA neonates and appropriate‐for‐gestational‐age (AGA) neonates, and to establish CBC reference values for full‐term SGA newborns. One hundred thirty‐two healthy, term newborns (73 SGA and 59 AGA) were included. On day 1, we obtained 109 samples and on day 7 we obtained 77 samples. A CBC and peripheral smear were analyzed for each sample collected and group data were compared. We observed higher mean values for normoblast count, hemoglobin, hematocrit, and red blood cell (RBC) count in the SGA babies than in the AGA babies on day 1. The mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration values for the SGA babies were decreased because of the relatively high RBC count and relatively high mean corpuscular volume we observed in this group. Of the SGA newborns, 21.9% had neutropenia and 4.7% had absolute neutrophil counts lower than 1500/μl on day 1. On both day 1 and day 7, the SGA newborns had higher mean absolute metamyelocyte counts and higher mean I : T (immature : total neutrophil ratio) values than the AGA group. The SGA babies had a lower mean absolute lymphocyte count on day 7 than the AGA group. We detected thrombocytopenia in almost one‐third of the 64 SGA newborns tested on day 1. In summary, our study clearly demonstrates that CBC parameters for healthy, full‐term, SGA newborns are different from those of healthy, term AGA newborns. This is the first study that has documented different mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, metamyelocyte counts, lymphocyte counts, and I : T in SGA babies compared with AGA babies.     

Complete blood count parameters for healthy, small-for-gestational-age, full-term newborns

No previous study has investigated the full range of complete blood count (CBC) parameters in small-for-gestational-age (SGA) newborns. The main aim of this study was to compare CBC and peripheral smear parameters in term, healthy SGA neonates and appropriate-for-gestational-age (AGA) neonates, and to establish CBC reference values for full-term SGA newborns. One hundred thirty-two healthy, term newborns (73 SGA and 59 AGA) were included. On day 1, we obtained 109 samples and on day 7 we obtained 77 samples. A CBC and peripheral smear were analyzed for each sample collected and group data were compared. We observed higher mean values for normoblast count, hemoglobin, hematocrit, and red blood cell (RBC) count in the SGA babies than in the AGA babies on day 1. The mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration values for the SGA babies were decreased because of the relatively high RBC count and relatively high mean corpuscular volume we observed in this group. Of the SGA newborns, 21.9% had neutropenia and 4.7% had absolute neutrophil counts lower than 1500/microl on day 1. On both day 1 and day 7, the SGA newborns had higher mean absolute metamyelocyte counts and higher mean I : T (immature : total neutrophil ratio) values than the AGA group. The SGA babies had a lower mean absolute lymphocyte count on day 7 than the AGA group. We detected thrombocytopenia in almost one-third of the 64 SGA newborns tested on day 1. In summary, our study clearly demonstrates that CBC parameters for healthy, full-term, SGA newborns are different from those of healthy, term AGA newborns. This is the first study that has documented different mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, metamyelocyte counts, lymphocyte counts, and I : T in SGA babies compared with AGA babies.     

Evaluation of hematological values obtained with reference automated hematology analyzers of six manufacturers

We evaluated assays of the same fresh blood samples with six different types of reference automated hematology analyzers developed by the following manufacturers: Beckman Coulter, Sysmex, Bayer, Abbott, Nihon Kohden and Horiba. Fresh whole blood samples treated with dipotassium ethylenediaminetetraacetic acid (EDTA K2) were collected from three healthy adult volunteers. The complete blood counts (CBC) including red blood cell count (RBC), hemoglobin (Hgb), hematocrit (Hct), mean corpuscular volume (MCV), white blood cell count (WBC), platelet count (Plt), reticulocyte percentage (Ret) and leukocyte differential counts including % neutrophils (Neu), % lymphocytes (Lym) and % monocytes (Mon) were surveyed with a reference automated hematology analyzer from each manufacturer. The process from sampling to analysis was performed according to procedures in hospital clinical laboratories. RBC, Hgb, Hct and MCV exhibited allowable differences within 5% of mean value among all instruments. Large differences greater than 10% of mean value in WBC, Neu and Lym between Horiba and other manufacturers, and in Plt between Nihon Kohden and other manufacturers, were observed. Ret and Mon exhibited large differences over 10% of mean value among almost all of the instruments tested. This survey suggests that all parameters exhibiting differences greater than 10% of mean value among instruments should be improved for clinical use to ensure good external quality control in blood cell counting and leukocyte differential counting using automated instruments.     

Study on the accuracy of automated hematology analyzers in Shanghai

The objectives of this study were to research on the accuracy of automated hematology analyzers of various types from different manufacturers and to observe the deviation among these instruments. Fresh anticoagulated blood from healthy donors on 115 hematology analyzers in 114 different hospitals were determined. RESULTS: The maximum coefficients of variation (CVs. %) among instruments of three main manufacturers (Sysmex, Beckman Coulter and Abbott) of red blood cell count (RBC), hemoglobin (Hgb), hematocrit (Hct), white blood cell count (WBC) and platelet count (Plt) were 3.2%, 3.8%, 3.6%, 9.3% and 10.8%, respectively. The maximum deviations among these parameters of different instruments were 0.74%, 1.65%, 5.45%, 7.06% and 18.55%, respectively. By improving laboratory quality management, the results of hematology analyzer determination may be more reliable than manual methods. The difference among various manufacturers was very small about RBC, Hgb, Hct, WBC and Plt the results from all kinds of instruments will tend to be comparable.     

Foot-strike haemolysis after a 60-km ultramarathon

Background.

The various contributors to sport-related anaemia include increased plasma volume, exercise-induced oxidative stress, increased body temperature, acidosis, gastrointestinal bleeding, acute and chronic inflammation as well as compression and damage of red blood cells (RBC) in the capillaries within the contracting muscles. The effective contribution of foot-strike haemolysis is unclear.

Materials and methods.

We studied 18 Caucasian male athletes (mean age, 42 years; range, 34–52 years) before and immediately after a 60-km ultramarathon. Laboratory investigations included the haematological profile along with haptoglobin, potassium, aspartate aminotransferase (AST), creatine kinase (CK), lactate dehydrogenase (LDH) and albumin concentrations and a haemolysis index (HI).

Results.

No significant variations were found in post-exercise values of haemoglobin, RBC count and haematocrit. Mean corpuscular volume and haptoglobin were significantly decreased, whereas RBC distribution width was increased. The concentration of haptoglobin was reduced by approximately 50%, whereas enzyme concentrations were all remarkably increased. The HI remained below 0.5 g/L. After adjusting for plasma volume change, the increases were 1.7% for potassium (P=0.17), 30% for AST (P<0.01), 49% for LDH (P<0.01) and 2.39-fold for CK (P<0.01). A statistically significant association was found between haemoconcentration-adjusted variations of CK and those of AST (r=0.803; P<0.01) and LDH (r=0.551; P=0.02).

Discussion.

This is the first study demonstrating that long-distance running does not induce clinically significant changes in haemoglobin, haematocrit, RBC count or potassium concentration. The significant post-exercise decrease of haptoglobin reflects a certain degree of haemolysis, but the concentration of cell-free haemoglobin remaining below 0.5 g/L and the non-significant variation in RBC count both indicate that the foot-strike haemolysis is very modest or even clinically negligible.     

RBC 6-TGN and hematological parameters in patients with Crohn's disease treated by azathioprine

OBJECTIVE: The immunosuppressive properties of azathioprine (AZA) are mediated by intracellular metabolism of 6-MP into its active metabolites 6-thiguanine nucleotide (6-TGN) and 6-methylmercaptopurine (6-MMP). The aims of this study were to correlate red blood cell (RBC) 6-TGN and hematological parameters and their change in adult patients with Crohn's disease (CD) treated by AZA and to determine independent factors enabling determination of RBC 6-TGN. METHODS: RBC 6-TGN concentration was determined with high performance liquid chromography (HLPC) performed on 74 hepa-rinized blood samples from 32 patients. Changes of hematological parameters were measured for each RBC 6-TGN concentration. RBC 6-TGN concentration above 235 pmol/8x108 RBC was proposed as the therapeutic level in patients treated by AZA. Correlations between the various parameters were assessed as appropriate. Logistic regression analysis was used to determinate independent variables. P<0.05 was considered significant. RESULTS: There was a positive correlation between RBC 6-TGN and decreased red cell count (DeltaRBC) (r=0.314; P=0.006), platelet count (DeltaPlatelets) (r=0.314; P=0.007), White cell count (DeltaWC) (r=0.241; P=0.04) and neutrophil count (DeltaPMN) (r=0.292; P=0.02). RBC 6-TGN in the therapeutic zone was positively correlated with mean corpuscular volume (MCV) (r=0.527; P=0.01), mean corpuscular hemoglobin concentration (MCHC) (r=0.437; P=0.04), increase in MCV (DeltaMCV) (r=0.512; P=0.012), decrease in White cell count (DeltaWC) (r=0451; P=003) and in neutrophil count (DeltaPMN) (r=0.463; P=0.03). Multivariate analysis showed that low activity of CD (P<0.02), young age at onset of treatment by AZA (P<0.03) and a low red cell distribution width (RDW) (P=0.003) were independent factors for RBC 6-TGN situated in therapeutic zone. RBC 6-TGN could be determined by logistic regression from AZA dose (mg/kg/d) and MCV increase. CONCLUSION: This study confirms that hematological parameters or their change can be used to determine whether RBC 6-TGN concentration has reached the therapeutic level. Logistic regression analysis showed that decreased RDW and increased MCV were independent factors for RBC 6-TGN level.     

Additional value of red blood cell parameters in predicting uncommon α-thalassemia; experience from 10 years of α-globin gene sequencing and copy number variation analysis

Introduction

The diagnosis of rare forms of α-thalassemia requires laborious genetic analyses. Accurate sample selection for such evaluation is therefore essential. The main objectives of this study were to investigate the predictive power of red blood cell parameters to detect rare forms of α-thalassemia (substudy 1), and to explore the frequency of rare versus common forms of α-thalassemia in our sample population (substudy 2).

Methods

In substudy 1, we reviewed all blood samples selected for extended α-hemoglobinopathy evaluation at our laboratory during 2011–2020 (n = 1217), which included DNA sequencing and/or copy number variation analysis. We assessed α-thalassemia positive samples at different levels of mean corpuscular hemoglobin (MCH) alone and in combination with results for red blood cell count (RBC) or red cell distribution width (RDW). In substudy 2, we examined the distribution of α-thalassemia genotypes for all samples submitted to a first-tier hemoglobinopathy evaluation at our laboratory during 2014–2020 (n = 6495).

Results

In substudy 1, both RBC and RDW added predictive value in detecting rare forms of α-thalassemia in samples from adults and children. In adult samples with MCH ≤ 23 pg, the presence of erythrocytosis increased the detection rate from 27% to 74% as compared to non-erythrocytosis, while normal RDW increased the detection rate from 36% to 86% as compared to elevated RDW. In substudy 2, rare forms of α-thalassemia were detected in 12% of α-thalassemia positive samples.

Conclusion

Initial assessment of MCH, RBC, and RDW provided valuable predictive information about the presence of rare forms of α-thalassemia during hemoglobinopathy evaluation.     

Evidence for linkage of red blood cell size and count: genome-wide scans in the Framingham Heart Study

Red blood cell (RBC) count and size are major criteria for evaluating anemia and related hematology disease diagnoses. While environmental factors influence RBC count (RBCC) and size, mean corpuscular volume (MCV), and mean corpuscular hemoglobin (MCH), studies have indicated that each of these measures has a substantial genetic component. So far, no linkage analysis or genome scan has been reported. We carried out 10 cM genome-wide scans on RBCC, MCV, and MCH in a community-based Caucasian cohort, the Framingham Heart Study, using 325 pedigrees with 1,144 individuals genotyped and phenotyped. Using variance-component linkage methods, heritabilities were estimated as 56, 52, and 52% after covariate adjusted for RBCC, MCV, and MCH, respectively. For RBCC, we found a maximum LOD score of 3.2 on chromosome 19, 24 cM (7.0 Mbp). Near this region, there lie a few important candidate genes, including erythropoietin receptor and erythroid Krüppel-like factor. For linkage analyses for MCV and MCH, there were coinciding maximized LOD scores on chromosome 11, 9 cM (5.2 Mbp) with values of 3.8 and 3.6, respectively. Under the peak resides the hemoglobin beta cluster - several beta-like genes, which are important candidates for RBC size. In subsequent analyses, we excluded individuals with low MCV to assess the possible influence of beta-thalassemia carriers, and there continued to be evidence for linkage in the same region on chromosome 11p15 (LOD scores of 2.6 and 2.7 for MCV and MCH, respectively). For MCV, we also identified a new region on chromosome 6q24 with a LOD score of 2.9. These findings suggest that further studies are warranted to identify potential causal genetic variants for RBC size and count and related erythrocyte indices.     

Pediatric Reference Intervals for Free Thyroxine and Free Triiodothyronine by Equilibrium Dialysis-Liquid Chromatography-Tandem Mass Spectrometry

Objective:

Thyroid hormone concentrations fluctuate during growth and development. To accurately diagnose thyroid disease in pediatric patients, reference intervals (RIs) should be established with appropriate age groups from an adequate number of healthy subjects using the most exact methods possible. Obtaining statistically useful numbers of healthy patients is particularly challenging for pediatric populations. The objective of this study was to determine non-parametric RIs for free thyroxine (fT4) and free triiodothyronine (fT3) using equilibrium dialysis-high performance liquid chromatography-tandem mass spectrometry with over 2200 healthy children 6 months-17 years of age.

Methods:

Subjects were negative for both thyroglobulin and thyroid peroxidase autoantibodies and had normal thyrotropin concentrations. The study included 2213 children (1129 boys and 1084 girls), with at least 120 subjects (average of 125) from each year of life, except for the 6 month to 1 year age group (n=96).

Results:

Non-parametric RIs (95th percentile) for fT4 were: 18.0-34.7 pmol/L (boys and girls, 6 months-6 years) and 14.2-25.7 pmol/L (boys and girls, 7-17 years). RIs for fT3 were: 5.8-13.1 pmol/L (girls, 6 months-6 years); 5.7-11.8 pmol/L (boys, 6 months-6 years); 5.7-10.0 pmol/L (boys and girls, 7-12 years); 4.5-8.6 pmol/L (girls, 13-17 years); and 5.2-9.4 pmol/L (boys, 13-17 years).

Conclusion:

Numerous significant differences were observed between pediatric age groups and previously established adult ranges. This emphasizes the need for well-characterized RIs for thyroid hormones in the pediatric population.     

Venous stasis and routine hematologic testing

Prolonged venous stasis, as generated by a long tourniquet placement, produces spurious variations in several measurable analytes. To verify to what extent venous stasis influences routine hematologic testing, we assessed routine hematologic parameters, including hemoglobin, hematocrit, red blood cell count (RBC), main cell hemoglobin (MHC), main cell volume (MCV), platelet count (PLT), main platelet volume (MPV), white blood cell count (WBC) and WBC differential on the Advia 120 automated hematology analyzer in 30 healthy volunteers, either without venous stasis (no stasis) or after application of a 60 mmHg standardized external pressure by a sphygmomanometer, for 1 (1-min stasis) and 3 min (3-min stasis). Although the overall correlation between measures was globally acceptable, the mean values for paired samples were significantly different in all parameters tested, except MCV, MHC, PLT, MPV, eosinophils, basophils and large unstained cells after 1-min stasis and all parameters except MCV, MHC, MPV and basophils after 3-min venous stasis. As expected RBC, hemoglobin and hematocrit displayed a significant trend towards increase, whereas WBC and the WBC subpopulations were decreased. Difference between measurements by Bland and Altman plots exceeded the current analytical quality specifications for desirable bias for WBC, RBC, hemoglobin, hematocrit, lymphocytes and monocytes in samples collected after either 1- and 3-min stasis. These results provide clear evidence that venous stasis during venipuncture might produce spurious and clinically meaningful biases in the measurement of several hematologic parameters, prompting further considerations on the usefulness of adopting appropriate preventive measures for minimizing such influences.     

OSAHS患儿血FIB、RBC相关指标变化及其临床意义探讨

目的 探讨阻塞性睡眠呼吸暂停低通气综合征(OSAHS)患儿血纤维蛋白原(FIB)、红细胞计数(RBC)相关指标变化及其临床意义.方法 回顾性分析2018年1月～2020年5月医院收治的90例OS-AHS患儿的资料,记为A组,另回顾性分析同期在该院体检的84例健康儿童的资料,记为B组.对比A组和B组血FIB、RBC、血红...     

Postnatal ontogeny of erythropoietin and hematology in free-ranging Steller sea lions (Eumetopias jubatus)

The hormone erythropoietin (EPO) is responsible for the increased production of red blood cells (RBC) in response to tissue hypoxia. While the role of EPO in hematological development has been established in humans and terrestrial mammals, this relationship has never been examined in marine mammals that rely heavily on stored oxygen to maintain aerobic metabolism while diving. Since blood is the major oxygen storage site in marine mammals, it was hypothesized that EPO may have a significant influence on the development of hematology parameters associated with the expansion of blood oxygen stores during development. To explore this hypothesis, serum EPO concentrations were determined by radioimmunoassay in 235 free-ranging Steller sea lions (Eumetopias jubatus), throughout their Alaskan range. Hematocrit (Hct), hemoglobin (Hb), and red blood cell (RBC) counts were also measured, and mean corpuscular hemoglobin content (MCHC), mean corpuscular volume (MCV), and mean corpuscular hemoglobin (MCV) values determined. Erythropoietin and most hematological parameters varied with age. Hematocrit, Hb, RBC, and MCHC decreased after birth, reached their lowest values at two to three months of age, and then increased to values similar to those of adults by five months of age. Since changes in Hct and Hb account for the majority of the changes in blood oxygen stores and EPO was negatively correlated with both, it appears that EPO may play an important role in blood development of Steller sea lions, similar to previous studies on terrestrial mammals.     

Reduction in Unnecessary Red Blood Cell Folate Testing by Restricting Computerized Physician Order Entry in the Electronic Health Record

Purpose

The red blood cell (RBC) folate test is a laboratory test with limited clinical utility. Previous attempts to reduce physician ordering of unnecessary laboratory tests, including folate levels, have resulted in only modest success. The objective of this study was to assess the effectiveness and impacts of restricting RBC folate ordering in the electronic health record (EHR).

Erythrocyte parameters in the elderly: an argument against new geriatric normal values

Erythrocyte parameters in 292 unselected geriatric patients were studied retrospectively. Statistically significant mean decreases compared to the laboratories' normal mean values were found in the red blood cell count (RBC), hemoglobin level, hematocrit, and mean corpuscular hemoglobin concentration; there also was a slight increase in mean corpuscular volume and mean corpuscular hemoglobin. However, when 17 patients with a hemoglobin level less than 10 gm/dl or a hematocrit reading less than 35 percent were excluded, all of the mean values for erythrocyte parameters fell within the normal range. In 71 percent of these 17 patients the etiology of the anemia was documented. Although one cannot definitely exclude a slight change in erythrocyte parameters with aging, it is concluded that the establishment of so-called new geriatric norms is premature, as the population studied included patients with various diseases. Good medical practice dictates continued evaluation and monitoring of patients in whom erythrocyte values are outside the established normal ranges.