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At least 19 recordsLinked to original sources
PubMed1989

Inaccuracy and imprecision of reticulocyte counting.

Reticulocyte count is an essential clinical test to detect erythropoietic activity. The test has been done manually with the use of one of three dyes: new methylene blue, brilliant cresyl blue, and azure B. When reticulocyte counts with the different dyes were compared, correlation was good. When reticulocyte counts obtained by use of the dyes were compared with the count obtained by an automated counter, correlation was high. In a sampling study, the specimen prepared by a spinner method gave smaller variations than a wedge method. Intertechnologist bias was higher than inter-specimen or intra-specimen bias: The variation of the reticulocyte count was examined with from 200 to 2,000 cells; with 1,000 cells or more, variation was low. From these results, we concluded that more than 1,000 erythrocytes on one slide prepared by the spinner method should be analyzed. Clear standards for cell identification are also needed.

Blood Cell Count↗
PubMed1996

The complete blood count and reticulocyte count--are they necessary in the evaluation of acute vasoocclusive sickle-cell crisis?

OBJECTIVE: To assess the usefulness of the complete blood count (CBC) and the reticulocyte count in the evaluation of adult patients with acute vasoocclusive sickle-cell crisis (SCC) presenting to the ED. METHODS: A 2-part study was performed. Part 1 was retrospective chart review of patients with a sole ED diagnosis of acute SCC. Part 2 was a prospective evaluation of consecutive patients presenting in SCC. In both parts of the study, patients with coexisting acute disease were excluded. The remaining patients were divided into 2 groups: admitted and released. The mean values for white blood cell (WBC) count, hemoglobin (Hb) level, and reticulocyte count were compared. In Part 2, the change (delta) from the patient's baseline in WBC count, Hb level, and reticulocyte count also was determined. Data were analyzed by 2-tailed Student's t-test. RESULTS: Part 1: There was no difference between the admitted (n = 33) and the released (n = 86) groups in mean WBC count (p = 0.10), Hb level (p = 0.25), or reticulocyte count (p = 0.08). Part 2: There was no difference between the admitted (n = 44) and the released (n = 160) groups in mean Hb level (p = 0.88), reticulocyte count (p = 0.47), delta Hb level (p = 0.88), and delta reticulocyte count (p = 0.76). There was a difference in mean WBC counts (15.8 +/- 4.9 x 10(9)/L admitted vs 12.8 +/- 4.9 x 10(9)/L released, p = 0.003) and delta WBC counts (5.1 +/- 4.6 x 10(9)/L admitted vs 1.8 +/- 4.6 x 10(9)/L released, p < 0.002). CONCLUSION: Determination of the Hb level and the reticulocyte count do not appear useful in the evaluation of acute SCC in the ED. Admission decisions appear associated with elevations in the WBC count. Further study is required to determine the true value of the WBC count in such decisions.

Adult↗
PubMed1989

Counting reticulocytes by flow cytometry: use of thiazole orange.

Thiazole orange is a new fluorescent dye which will bind to the residual RNA in the cytoplasm of reticulocytes and allow their enumeration by FACS analysis. We have evaluated the use of this dye in the routine haematology laboratory. There is an excellent correlation between manual and FACS reticulocyte counts (r = 0.98) but FACS counting showed significantly higher precision (CV = 3.1) than the manual method (CV = 11.9) for single observer, 20.8% for multiple observers). Clinical specimens showed stable reticulocyte counts for 6 h if stored at 4 degrees C allowing efficient batching of samples. There was a significant fall in reticulocyte counts stored for 24 h at both 4 degrees C and 21 degrees C. Evaluation of 78 male and 76 female blood donors by FACS analysis gave normal ranges (mean % +/- 2 SD) of 0.74 +/- 0.48 and 0.84 +/- 0.56 respectively (P less than 0.005). When corrected to absolute values there was no sex difference (36 +/- 24 x 10(9)/l). Thiazole orange is an effective stain for the automated counting of reticulocytes by FACS analysis.

Benzothiazoles↗
PubMed1992

Multivariate statistical modeling: alternative approach to test evaluation, applied to counting reticulocytes by flow cytometry.

We present a statistical path analysis model for the evaluation of two tests in the absence of a "gold standard" method. This model is applied to the evaluation of flow-cytometric and visual reticulocyte counting by using as the comparison method a combination of three hematological measurements: hemoglobin concentration (HGB), mean cellular volume (MCV), and erythrocyte density width (EDW). We assumed that, in general, a higher reticulocyte count is associated with a lower HGB value and with greater values for MCV and EDW. Applying this assumption and the statistical model, we demonstrated that flow cytometry was superior to visual reticulocyte counting in the low-value range studied. The path analysis model is potentially applicable in other cases where two tests are to be compared, and when no gold standard is available.

Erythrocyte Count↗
PubMed1997

Automated reticulocyte counting: evaluation of the Coulter STKS Haematology Analyser reticulocyte counting function.

This study evaluated reticulocyte counting with the automated reticulocyte function of the Coulter STKS Haematology Analyser. This is an upgrade option for Coulter STKS and MAXIM haematology analysers. Reticulocyte counts obtained with the automated reticulocyte counting function were compared with those obtained by visual counting. Reticulocyte counting with both methods gave excellent comparability with a correlation coefficient of 0.98. Results were consistent with the well documented imprecision of the manual method with a coefficient of variation (CV) of 16-22%. In contrast, the automated reticulocyte counting function was more precise with a CV of 12.3%. In both cases, counts were stable after storage for 24 h at room temperature and 4 degrees C. Our results suggest that the use of this upgrade will be beneficial for many laboratories.

Autoanalysis↗
PubMed1981

The effect of controlled daily blood loss on the haemoglobin concentration, erythrocyte count and reticulocyte count of male rats.

0.2, 0.6 or 1 ml of blood was removed from rats once daily on 17 consecutive days. Haemoglobin concentration and erythrocyte counts fell rapidly until day 7 or 9 and were reflected after day 2 by an increase in reticulocytes. From 9 to 17 there was little further change and 14 days after the last bleed the haematological results were within the normal range. The increase in haemoglobin production correlated well with the increase in reticulocyte numbers.

Animals↗
PubMed1994

Automated reticulocyte counting and measurement of reticulocyte cellular indices. Evaluation of the Miles H*3 blood analyzer.

This study evaluated reticulocyte counting and measurement of reticulocyte cellular indices with the Miles H*3 blood analyzer, a new instrument that combines the Technicon/Miles technology for blood cells counting with a staining technique allowing counting of reticulocytes, quantification of staining intensity and measurement of reticulocyte cellular indices. Reticulocyte counts obtained with the Miles H*3 analyzer were compared with those obtained by manual counting, flow cytometry (thiazole orange method) and by the Sysmex R-3000 (Baxter Diagnostics) reticulocyte analyzer. Reticulocyte counting with the Miles H*3 showed excellent precision, and linearity in the range tested (1.1-49% and 1-72% reticulocytes, respectively, with two different protocols) with no significant carryover. Reticulocyte counts were stable after storing blood samples for 72 hours at 4 degrees C. Comparison of the four different methods, showed an acceptable intraclass correlation between Miles H*3 and Sysmex R-3000 (intraclass correlation coefficient, [ri] = .952), Miles H*3 and flow cytometry (ri = .922), and Sysmex R-3000 and flow cytometry (ri = .938). There was no satisfactory correlation between any of the three automated methods and the values obtained with manual counting of reticulocytes (ri = .538-.755), consistent with the well known imprecision of the manual technique. For a group of normal pediatric subjects, age 1-10, we obtained the following values (+/- SD) of reticulocyte indices: mean corpuscular volume 97.6 +/- 4.7 fL; cell hemoglobin concentration mean 28.2 +/- 1.4 g/dL; cell hemoglobin content 26.7 +/- 1.6 pg. We determined the direct cost, including depreciation, of the manual and instrumental methods. Cost/test varied from $1.61 for manual method to $6.03 for the Sysmex R-3000. Cost/test for flow cytometry and Miles H*3 were $3.34 and $3.49, respectively.

Child↗
PubMed1989

[Reticulocyte counts in the aged].

Reticulocytes were measured on an automated reticulocyte counter in five groups; healthy adults, non-elderly patient with low hematopoiesis, adults with anemia, healthy elderly persons and elderly patients with anemia. The reticulocyte percent, absolute reticulocyte count, and reticulocyte composition as classified by fluorescence intensity (highly, moderately, and slightly fluorescent cells) were calculated. The healthy adults had a reticulocyte count of 0.70 +/- 0.55%, an absolute reticulocyte count of 4.36 +/- 1.90 X 10(4)/microliters, 2.33 +/- 1.95% highly fluorescent cells, 18.73 +/- 5.07% of moderately fluorescent cells, and 78.82 +/- 6.55% of slightly fluorescent cells. Patients with low hematopoiesis had lower counts except for the percentage of slightly fluorescent cell. Aged persons without anemia showed no differences in reticulocytes from healthy adults. However, elderly patients with anemia had a low reticulocyte count; there was no tendency towards an increase in the percentage of highly fluorescent cells or a decrease in the percentage of slightly fluorescent cells. Their reticulocyte percent was not significantly higher than healthy controls, suggesting that anemia observed in the aged arises from low hematopoietic activity in the bone marrow.

Adult↗
PubMed1989

An automated reticulocyte counting method: preliminary observations.

We evaluated the counting of reticulocytes in the peripheral blood with a newly developed flow cytometer type of automated counter that performs a single test within 60 s. The volume of sample needed is 100 microliters and the cells are stained with auramine-O in the counter. The mean within-run reproducibility was 4.66% (CV, n = 50), and dilution of blood gave highly linear results with an r value of 0.996. Correlation was good between manual reticulocyte counts and those performed with the counter (r = 0.893). Samples with large numbers of leucocytes, erythrocytes, or platelets did not interfere with the automated reticulocyte counting, and provided accurate and precise data.

Autoanalysis↗
PubMed1993

Evaluation of erythropoietic/hematopoietic reconstitution after BMT by highly fluorescent reticulocyte counts compares favorably with traditional peripheral blood cell counting.

Highly fluorescent reticulocyte (HFR) counts and reticulocyte counts were analyzed daily using a Sysmex R-1000 automated reticulocyte counter after 42 BMT in children (median age 7 years, range 10 month-18.5 years). White blood cell levels were also analyzed daily using either traditional counting methods or, when levels were very low, cytocentrifuge preparations. Twenty-eight patients received autologous and 14 allogeneic BMT. After myeloablative therapy, HFR counts fell to zero and rose to 2% of the reticulocyte total after a median time of 10 days (range 6-23 days) post-autoBMT and 14 days (range 9-29 days) post-alloBMT. The appearance of HFR (at least 2% in two successive counts) preceded the attainment of 20 x 10(9)/l reticulocytes in 23 of 26 autoBMT by a median time of 3 days, and in 13 of 13 alloBMT with a median time of 4 days (p < 0.001). Two per cent HFR preceded the attainment of 0.5 x 10(9)/l neutrophils in the majority of BMT by a median time > 6 days (p < 0.001). The attainment of 0.05 x 10(9)/l monocytes was preceded by a rise in HFR in 12 of 26 autoBMT and in 7 of 13 alloBMT. Median times between 2% HFR and monocyte levels of 0.05 x 10(9)/l were respectively 2 (range 0- > 24) and 3 (range: 0- > 19) days after auto and alloBMT. These results show that the evaluation of erythropoiesis following BMT by means of HFR counting provides an early measure of hematopoietic reconstitution which is as precise and considerably more practical than monitoring the monocyte level.

Adolescent↗
PubMed1985

Analytic inaccuracy and imprecision in reticulocyte counting: a preliminary report from the College of American Pathologists Reticulocyte Project.

Precision and accuracy of reticulocyte counting appears to require significant improvement. Several poorly controlled analytic variables affect reticulocyte count performance including sample size, use of an ocular insert, interobserver variation in reticulocyte definition, and possibly the type of blood smear evaluated. These sources of imprecision and inaccuracy are discussed, and new data from the initial phases of the College of American Pathologists assessment of reticulocyte counting are presented. Recommendations for analytic goals for both manual and automated reticulocyte counting are provided.

Automation↗
PubMed1994

Yield of reticulocyte counts and blood smears in term infants.

Reticulocyte counts and blood smears are commonly recommended to evaluate jaundice in newborns. To investigate the results and diagnostic yield of these tests, we reviewed a computerized database and medical records of term newborns who had reticulocyte counts (n = 799) or blood smears (n = 781) within the first week after birth at two hospitals. Nearly a threefold difference was noted in reticulocyte counts between the two hospitals (median 8.0% vs 2.8%; P < .0001), apparently due to differences in laboratory methods. Among the patients with "abnormal" reticulocyte counts or blood smears (n = 192), isoimmunization was diagnosed in 54, presumed hemolysis of unknown etiology in two, G6PD deficiency in one, and pyropoikilocytosis in one. We conclude that better standardization of reticulocyte counts is needed. When ordered as screening tests for hemolysis in jaundiced infants, reticulocyte counts and blood smears seldom lead to diagnoses of hemolysis other than isoimmunization.

Bilirubin↗
PubMed1994

Do the reticulocyte maturation fractions and bone marrow reticulocyte count further help the classification of anemias?

BACKGROUND: Reticulocyte count plays a major role in anemic evaluation. The conventional method done by the manual supravital staining cannot subclassify the group of less than 2% of corrected reticulocyte count. The newly-developed flow cytometer provides different maturation fractions by measuring its fluorescent intensity. The reticulocytes are believed to shift to the circulation from the bone marrow earlier in more severe anemia. Therefore, the purpose of this study is to evaluate the role of reticulocyte maturation fractions and bone marrow reticulocyte in anemia classification. METHODS: By using a fully automated counter, the roles of the reticulocyte with maturation and their shifting from bone marrow were evaluated in anemias. Different groups of subjects (243 in total) including aplastic, nutritional, and infiltrative anemias and anemia due to excess destruction and blood loss were studied. Each subject had bone marrow examination for morphologic diagnosis and reticulocyte evaluation. RESULTS: Both the absolute count and the maturation fractions of reticulocytes showed significant difference among marrow infiltration, aplastic anemia, and hemolytic anemia. Both the absolute reticulocyte count and less mature fractions were lowest in aplastic group. The marrow reticulocyte counts and shift ratio to circulating blood added little benefit in the classification of anemias. CONCLUSIONS: The automated reticulocyte count with maturation fractions helps classify anemias, particularly for those with low reticulocyte count by the manual method.

Adolescent↗
PubMed1997

Comparison of a semi-automated new Coulter methylene blue method with fluorescence flow cytometry in reticulocyte counting.

A semi-automated new methylene blue method for reticulocyte counting was compared to the manual method and fluorescence flow cytometry. Over a wide range of reticulocyte counts (0.3-12.7%) the new methylene blue method was found to be comparable to that of fluorescence flow cytometry, with high precision. Between-run precision studies showed coefficients of variation (CVs) of 4.8, 6.9 and 14.5% for reticulocyte counts of 9.5, 2.4 and 0.7%, respectively. Within-run precision studies showed CVs of 8.6, 8.1 and 6.1% for reticulocyte counts of 0.9, 5.3, and 18.4%, respectively. The correlation coefficient between the Coulter method and the manual method was 0.83, and 0.85 between the Coulter method and flow cytometry. The possibility of extending the incubation time to at least 4 h and the insignificant changes observed with samples stored for up to at least 72 h at 4-8 degrees C make this new method most convenient and allow any laboratory having Coulter STKS or MAXM cell counters to perform reticulocyte counts in an efficient, reliable manner.

Cell Separation↗
PubMed1991

Comparison of a modified thiazole orange technique with a fully automated analyser for reticulocyte counting.

Two independent methods for quantitating reticulocyte counts were compared. One used a modified thiazole orange technique and a flow cytometer (Becton Dickinson FACS); the other was a fully automated whole blood analyser (Sysmex R1000). Both methods gave comparable results with a coefficient of variation of less than 5%. Samples measured using the R1000 showed a negligible decrease in the reticulocyte count over five days at room temperature, although there was evidence of continuing intracellular maturation: with thiazole orange there was an apparent increase. A practical reference range of 20-70 x 10(9)/l was established from 89 normal subjects. The close correlation between the two independent estimates indicates the validity of the quantitation of the reticulocyte count and shows that automation allows significant changes within and below the normal range to be detected with a degree of reliability which was not previously possible.

Benzothiazoles↗
PubMed1989

[Automated measurement of reticulocyte count by flow cytometry. II: Analysis of the blood containing abnormal erythrocytes or giant platelets].

We have examined the influence of erythrocytes containing inclusion bodies, nucleated red cells or giant platelets on the measurement of reticulocyte count by automated machine, R-1000. Correlation of the reticulocyte count between automated and conventional method was extremely good in the blood containing red cells with Jolly bodies, Pappenheimer bodies or basophilic stippling . However, correlation was poor when the sample contained the nucleated red cells. Reticulocyte count was decreased in the blood with significant amounts of nucleated red cells. Since nucleated red cells themselves are not counted as reticulocytes in the machine, this was considered to be due to increased young reticulocytes which frequently appeared with nucleated red cells. Both cold agglutinated red cells and giant platelets apparently influenced the reticulocyte count by the R-1000. These results suggest that red cells with Jolly bodies, Pappenheimer bodies or basophilic stippling do not influence the automatic counting of reticulocytes. Although nucleated red cells, cold agglutinated red cells and giant platelets affected the reticulocyte count, the machine shows abnormal flags in most of above cases (except highly agglutinated red cells), so that one can recount reticulocytes by conventional method. We conclude the machine can safely count the reticulocytes even in the blood containing abnormal red cells or platelets.

Blood Platelets↗
PubMed1990

Evaluation of reticulocyte counts by flow cytometry in a routine laboratory.

Reticulocyte counting using flow cytometry and a membrane-permeable fluorescent dye, thiazole orange, was evaluated as an alternative to the conventional manual method. The flow cytometric method was more precise (mean c.v. of 4.3%) than the imprecise manual technique (mean c.v. of 22.4%). Linearity was highly acceptable (r = 0.99) over the reticulocyte count range of 1.8-30.1%. Flow cytometry allows processing of large numbers of samples with reduction in technologist time, and the improved precision and tenfold increase in the number of cells counted should considerably improve the clinical utility of the reticulocyte count.

Adult↗