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The Clinical Detection of Variations in the Concentrations of Normal Leukocyte Types:

A Laboratory Comparison of 100-Cell Manual Differential Counts on Wedge Smears and 500-Cell Counts by the ADC500
  • Philip R. Daoust
Conference paper

Abstract

This study represents part of a clinical evaluation of the ADC500 automated leukocyte differential counter: 100-cell manual eye-counts on wedge smears prepared in a semi-automated fashion were compared with automated 500-cell counts on spun smears, and normal ranges of total cell concentrations were established for both methods. For each method, and in an unselected consecutive patient population, variations in total cell concentrations by cell class were recorded and analyzed as to their differences from established normals and the degree of significance of their differences. The data show that the automated method is in good agreement with manual counts, but detects variations in concentration with a greater degree of confidence, when comparisons are made with normality. This is presumed to be at least partially due to a reduction of within-slide statistical sampling error. However, it may also reflect the nonrandom and irregular distribution of cells on the wedge smear and the nonrandom search pattern conducted by the technologist during manual eye-counts. Differences in the distributions of normal values for monocytes by method are noted. An increased sensitivity of the ADC500 to monocytosis and lymphocytopenia is described. Improved reporting formats for automated imaging systems are discussed based upon the approach taken in this study. The clinician should be provided with data in the form of absolute cell concentrations, with an indication of the unique within-specimen statistical variation affecting the result, and finally, if the measurement varies from normality, the degree of confidence in the variation. This approach only addresses methodological variation. As others have pointed out, physiologic diurnal variations in leukocyte concentrations are significant and must be considered in relation to the timing of phlebotomy and the ultimate interpretation of any detected variations in concentration.

Key Words

Total leukocyte concentrations Automated differential instrumentation Data reporting Clinical interpretation 

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References

  1. 1.
    BACUS, J. W.: The observer error in peripheral blood cell classification. Am. J. Clin. Pathol. 59, 223–230, 1973 PubMedGoogle Scholar
  2. 2.
    BACUS, J. W.: Erythrocyte morphology and centrifugal “spinner” blood film preparations. J. Histochem. Cytochem. 22, 506–516, 1974 PubMedCrossRefGoogle Scholar
  3. 3.
    BARNETT, C. W.: The unavoidable error in the differential count of the leukocytes of the blood. J. Clin. Invest. 12, 77–85, 1933 PubMedCentralPubMedCrossRefGoogle Scholar
  4. 4.
    BROWN, T. R.: The changes of the leucocytes in disease as an aid to diagnosis and prognosis. Trans. Med. Soc. State N.Y. 1902 Google Scholar
  5. BROWN, T. R.: The changes of the leucocytes in disease as an aid to diagnosis and prognosis. Ann. Med. 10, 769, 1905 Google Scholar
  6. 5.
    DAVIDSON, E.: The distribution of cells in peripheral blood smears. J. Clin. Pathol. 11, 410–411, 1958 PubMedCrossRefGoogle Scholar
  7. 6.
    GABRIELLI, E. R.: Standardized interpretation of laboratory data. Ann. N.Y. Acad Sci. 161, 460–76, 1969 CrossRefGoogle Scholar
  8. 7.
    MAINLAND, D.: Normal values in medicine. Ann. N. Y. Acad. Sci. 161, 527–537, 1969 PubMedCrossRefGoogle Scholar
  9. 8.
    MANSBERG, H. P., et al.: The Hemalog D white cell differential system. J. Histochem. Cytochem. 22, 711–724, 1974 PubMedCrossRefGoogle Scholar
  10. 9.
    NOURBAKHSH, M., et al.: An evaluation of blood smears made by a new method using a spinner and diluted blood. Am. J. Clin. Pathol. 70, 885–892, 1978 PubMedGoogle Scholar
  11. 10.
    PIERRE, R. V., O’SULLIVAN, M. B.: Evaluation of the Hemalog D automated differential leukocyte counter. Mayo Clin. Proc. 49, 870–874, 1974 PubMedGoogle Scholar
  12. 11.
    ROGERS, C. H.: Blood sample preparation for automated differential systems. Am. J. Med. Technol. 39, 435–442, 1973 PubMedGoogle Scholar
  13. 12.
    ROSVOLL, R. V., et al.: Visual and automated differential leukocyte counts. A comparison study of three instruments. Am. J. Clin. Pathol. 71, 695–703, 1979 PubMedGoogle Scholar
  14. 13.
    RUMKE, C. L., et al.: Normal values and least significant differences for differential leukocyte counts. J. Chronic Dis. 28, 661–668, 1975 PubMedCrossRefGoogle Scholar
  15. 14.
    RUMKE, C.L.: Variability of results in differential cell counts on blood smears. Triangle 4, 154–157, 1960Google Scholar
  16. 15.
    SIMMONS, A., et al.: Factors affecting manual white cell differential counts. Am. J. Med. Technol. 39, 354–359, 1973 PubMedGoogle Scholar
  17. 16.
    STATLAND, B. E., et al.: Evaluation of biologic sources of variation of leukocyte counts and other hematologic quantities using very precise automated analyzers. Am. J. Clin. Pathol. 69, 48–54, 1978 PubMedGoogle Scholar
  18. 17.
    WINTROBE, M. M.: Diagnostic significance of changes in leukocytes. Bull. N.Y. Acad. Med. 15, 223, 1939 PubMedCentralPubMedGoogle Scholar
  19. 18.
    WINTROBE, M. M.: Clinical Hematology, 7th edn. Philadelphia, Lea and Febiger, 1974 Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1981

Authors and Affiliations

  • Philip R. Daoust
    • 1
  1. 1.New England Medical Center Hospital, the Clinical Unit of the Tufts — New England CenterBostonUSA

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