Evaluation of Biologic Sources of Variation of Leukocyte Counts and Other Hematologic Quantities Using Very Precise Automated Analyzers

Abstract

The authors determined mean day-to-day (daily over five days), mean week-to-week (weekly over five weeks) and mean hour-to-hour (800 h, 1100 h, 1400 h) physiologic intra-individual variation of concentration values of leukocyte cell types, platelet count, and erythrocyte values (hematocrit, hemoglobin) for a group of 20 healthy adult volunteers. Total leukocyte counts and concentration values of leukocyte cell types were determined in duplicate on the Hemalong-DTM Automated Leukocyte Differential Cell Counter to minimize analytic variation. The data sets were analyzed according to an analysis of variance model. The mean physiologic hour-to-hour and week-to-week intra-individual variations in terms of % coefficient of variation included: hemoglobin, 2.5, 2.2; hematocrit, 2.6, 2.7; platelets, 1.6, 6.6; total leukocyte count, 9.4, 15.7; neutrophils, 12.9, 26.0; lymphocytes, 10.3, 13.2; monocytes, 18.6, 19.3; eosinophils, 19.9, 26.9; basophils, 7.4, 15.0; large unstained cells, 13.7, 16.0; "high-peroxidase" cells, 32.7, 25.7. Hour-to-hour variation was partitioned into random diurnal variation, group-consistent diurnal variation, and subject-specific unique individual variation. Subject-specific diurnal variation contributed greatly and statistically significantly to total diurnal variation for many of the leukocyte cell types--especially in the case of eosinophils, where it represented more than half of total diurnal variation.

Short-Term and Long-Term Intra-Individual Variations and Critical Differences of Haematological Laboratory Parameters

“…While studying the literature on the intra-individual variability of haematological data, our attention was drawn to two papers by Statlandet al (3,4). Comparison of our results with data from the literature (tab.8) could not be made for the critical differences, äs these have not been reported before in this field.…”

“…There has been an especial improvement in the precision of the differential count, mainly due to the fact that the analyser screens about 10000 leukocytes in each analysis (1)(2)(3)(4).…”

Biological Variations of Hematologic Parameters Determined by UniCel DxH 800 Hematology Analyzer

“…1 Our results are slightly different from the previously published observations, which showed hour-to-hour and subject-specific diurnal fluctuation. 5,6 For example, the study by Sennels et al 5 demonstrated diurnal variation of hematology parameters. In this study, samples were collected every third hour through 24 hours, 9 time points in total, in contrast to 3 time points during an 8-hour interval in our study.…”

“…[2][3][4][5][6][7][8][9] Some parameters, such as hemoglobin or reticulocytes, have been demonstrated to exhibit hour-to-hour, day-to-day, or seasonal intraindividual fluctuation. 3,6 We revisit these areas for several reasons. First of all, we use the newest model of automated hematology analyzer, UniCel DxH 800 (Beckman Coulter, Inc, Fullerton, California).…”

“…Second, almost all the reported studies in the past have been based entirely on Caucasian/white populations. [2][3][4][5][6][7][8][9] There is little knowledge about biological variation of hematologic parameters among Asian populations. Third, many new hematologic parameters have become available from modern automated hematology analyzers in recent years.…”