• 1. Cowgill ES, Neel JA, Grindem CB. Clinical application of reticulocyte counts in dogs and cats. Vet Clin North Am Small Anim Pract 2003; 33: 12231244.

    • Search Google Scholar
    • Export Citation
  • 2. Tvedten H. Laboratory and clinical diagnosis of anemia. In: Weiss DJ, Wardrop KJ, eds. Schalm's veterinary hematology. 6th ed. Ames, Iowa: Wiley-Blackwell, 2010;152161.

    • Search Google Scholar
    • Export Citation
  • 3. Hodges J, Christopher MM. Diagnostic accuracy of using erythrocyte indices and polychromasia to identify regenerative anemia in dogs. J Am Vet Med Assoc 2011; 238: 14521458.

    • Search Google Scholar
    • Export Citation
  • 4. Weiss DJ. Bone marrow pathology in dogs and cats with non-regenerative immune-mediated haemolytic anaemia and pure red cell aplasia. J Comp Pathol 2008; 138: 4653.

    • Search Google Scholar
    • Export Citation
  • 5. Rizzi TE, Meinkhot JH, Clinkendeard KD. Normal hematology of the dog. In: Weiss DJ, Wardrop KJ, eds. Schalm's veterinary hematology. 6th ed. Ames, Iowa: Wiley-Blackwell, 2010;799810.

    • Search Google Scholar
    • Export Citation
  • 6. Lilliehöök I, Tvedten H. Validation of the Sysmex XT-2000iV hematology system for dogs, cats, and horses. I. Erythrocytes, platelets, and total leukocyte counts. Vet Clin Pathol 2009; 38: 163174.

    • Search Google Scholar
    • Export Citation
  • 7. Moritz A, Becker M. Automated hematology systems. In: Weiss DJ, Wardrop KJ, eds. Schalm's veterinary hematology. 6th ed. Ames, Iowa: Wiley-Blackwell, 2010;10541066.

    • Search Google Scholar
    • Export Citation
  • 8. Tvedten H, Moritz A. Reticulocyte and Heinz body staining and enumeration. In: Weiss DJ, Wardrop KJ, eds. Schalm's veterinary hematology. 6th ed. Ames, Iowa: Wiley-Blackwell, 2010;10671073.

    • Search Google Scholar
    • Export Citation
  • 9. Moritz A, Fickenscher Y, Meyer K, et al. Canine and feline hematology reference values for the ADVIA 120 hematology system. Vet Clin Pathol 2004; 33: 3238.

    • Search Google Scholar
    • Export Citation
  • 10. Bourgès-Abella N, Geffré A, Concordet D, et al. Canine reference intervals for the Sysmex XT-2000iV hematology analyzer. Vet Clin Pathol 2011; 40: 303315.

    • Search Google Scholar
    • Export Citation
  • 11. Campora C, Freeman KP, Serra M, et al. Reference intervals for Greyhounds and lurchers using the Sysmex XT-2000iV hematology analyzer. Vet Clin Pathol 2011; 40: 467474.

    • Search Google Scholar
    • Export Citation
  • 12. Serra M, Freeman KP, Campora C, et al. Establishment of canine hematology reference intervals for the Sysmex XT-2000iV hematology analyzer using a blood donor database. Vet Clin Pathol 2012; 41: 207215.

    • Search Google Scholar
    • Export Citation
  • 13. Collicutt NB, Grindem CB, Neel JA. Comparison of manual polychromatophilic cell and automated reticulocyte quantification in evaluating regenerative response in anemic dogs. Vet Clin Pathol 2012; 41: 256260.

    • Search Google Scholar
    • Export Citation
  • 14. Riley RS, Ben-Ezra JM, Goel R, et al. Reticulocytes and reticulocyte enumeration. J Clin Lab Anal 2001; 15: 267294.

  • 15. Christian JA. Erythrokinetics and erythrocyte destruction. In: Weiss DJ, Wardrop KJ, eds. Schalm's veterinary hematology. 6th ed. Ames, Iowa: Wiley-Blackwell, 2010;136143.

    • Search Google Scholar
    • Export Citation
  • 16. Bossuyt PM, Reitsma JB, Bruns DE, et al. STARD 2015: an updated list of essential items for reporting diagnostic accuracy studies. BMJ 2015; 351: h5527.

    • Search Google Scholar
    • Export Citation
  • 17. Bossuyt PM, Reitsma JB, Bruns DE, et al. The STARD statement for reporting studies of diagnostic accuracy: explanation and elaboration. Clin Chem 2003; 49: 718.

    • Search Google Scholar
    • Export Citation
  • 18. Weiss DJ. Drug-induced blood cell disorders. In: Weiss DJ, Wardrop KJ, eds. Schalm's veterinary hematology. 6th ed. Ames, Iowa: Wiley-Blackwell, 2010;98105.

    • Search Google Scholar
    • Export Citation
  • 19. Gardner IA, Greiner M. Receiver-operating characteristic curves and likelihood ratios: improvements over traditional methods for the evaluation and application of veterinary clinical pathology tests. Vet Clin Pathol 2006; 35: 817.

    • Search Google Scholar
    • Export Citation
  • 20. Christenson RH. Evidence-based laboratory medicine—a guide for critical evaluation of in vitro laboratory testing. Ann Clin Biochem 2007; 44: 111130.

    • Search Google Scholar
    • Export Citation
  • 21. Albert A. On the use and computation of likelihood ratios in clinical chemistry. Clin Chem 1982; 28: 11131119.

  • 22. Friedrichs KR, Harr KE, Freeman KP, et al. ASVCP reference interval guidelines: determination of de novo reference intervals in veterinary species and other related topics. Vet Clin Pathol 2012; 41: 441453.

    • Search Google Scholar
    • Export Citation
  • 23. Fry MM, Kirk CA. Reticulocyte indices in a canine model of nutritional iron deficiency. Vet Clin Pathol 2006; 35: 172181.

  • 24. Weiss DJ. Iron and copper deficiencies and disorders of iron metabolism. In: Weiss DJ, Wardrop KJ, eds. Schalm's veterinary hematology. 6th ed. Ames, Iowa: Wiley-Blackwell, 2010;167171.

    • Search Google Scholar
    • Export Citation
  • 25. Weiss DJ. Pure red cell aplasia. In: Weiss DJ, Wardrop KJ, eds. Schalm's veterinary hematology. 6th ed. Ames, Iowa: Wiley-Blackwell, 2010;251255.

    • Search Google Scholar
    • Export Citation
  • 26. Weiss DJ. Myelodysplastic syndromes. In: Weiss DJ, Wardrop KJ, eds. Schalm's veterinary hematology. 6th ed. Ames, Iowa: Wiley-Blackwell, 2010;467474.

    • Search Google Scholar
    • Export Citation
  • 27. Johnson WO, Gastwirth JL, Pearson LM. Screening without a “gold standard”: the Hui Walter model revisited. Am J Epidemiol 2001; 153: 921924.

    • Search Google Scholar
    • Export Citation

Advertisement

Sensitivity and specificity of manual and automated measurements of reticulocyte parameters for classification of anemia in dogs: 174 cases (1993–2013)

Saverio Paltrinieri DVM, PhD1, Gabriele Rossi DVM, PhD2, Michela Manca DVM3, Paola Scarpa DVM, PhD4, Tiziana Vitiello DVM, PhD5, and Alessia Giordano DVM, PhD6
View More View Less
  • 1 Department of Veterinary Medicine, University of Milan, 20133, Milan, Italy.
  • | 2 Department of Veterinary Medicine, University of Milan, 20133, Milan, Italy.
  • | 3 Department of Veterinary Medicine, University of Milan, 20133, Milan, Italy.
  • | 4 Department of Veterinary Medicine, University of Milan, 20133, Milan, Italy.
  • | 5 Department of Veterinary Medicine, University of Milan, 20133, Milan, Italy.
  • | 6 Department of Veterinary Medicine, University of Milan, 20133, Milan, Italy.

Abstract

OBJECTIVE To assess sensitivity and specificity of manual and automated measurements of reticulocyte percentage, number, and production index for classification of anemia in dogs.

DESIGN Retrospective case series

SAMPLE 174 blood smears from client-owned dogs with anemia collected between 1993 and 2013 for which reticulocyte parameters were determined manually (nonregenerative anemia, 22; preregenerative anemia, 23; regenerative anemia, 28) or with an automated laser-based counter (nonregenerative anemia, 66; preregenerative anemia, 17; regenerative anemia, 18).

PROCEDURES Diagnostic performance was evaluated with receiver operating characteristic (ROC) curves by considering preregenerative anemia as nonregenerative or regenerative. Sensitivity, specificity, and positive likelihood ratio were calculated by use of cutoffs determined from ROC curves or published reference limits.

RESULTS Considering preregenerative anemia as non regenerative, areas under the curve (AUCs) for reticulocyte percentage, number, and production index were 97%, 93%, and 91% for manual counting and 93%, 90%, and 93% for automated counting. Sensitivity, specificity, and positive likelihood ratio were 82% to 86%, 82% to 87%, and 4.6 to 6.4, respectively. Considering preregenerative anemia as regenerative, AUCs were 77%, 82%, and 80% for manual counting and 81%, 82%, and 92% for automated counting. Sensitivity, specificity, and positive likelihood ratio were 72% to 74%, 76 to 87%, and 2.7 to 6.2, respectively.

CONCLUSIONS AND CLINICAL RELEVANCE Whereas all reticulocyte parameters identified regeneration in anemic dogs, the performance of specific parameters was dependent on the method used. Findings suggested that lower cutoffs than published reference limits are preferred for reticulocyte number and production index and higher cutoffs are preferred for reticulocyte percentage. Reticulocyte production index may be useful when the pretest probability of regeneration is moderate.

Abstract

OBJECTIVE To assess sensitivity and specificity of manual and automated measurements of reticulocyte percentage, number, and production index for classification of anemia in dogs.

DESIGN Retrospective case series

SAMPLE 174 blood smears from client-owned dogs with anemia collected between 1993 and 2013 for which reticulocyte parameters were determined manually (nonregenerative anemia, 22; preregenerative anemia, 23; regenerative anemia, 28) or with an automated laser-based counter (nonregenerative anemia, 66; preregenerative anemia, 17; regenerative anemia, 18).

PROCEDURES Diagnostic performance was evaluated with receiver operating characteristic (ROC) curves by considering preregenerative anemia as nonregenerative or regenerative. Sensitivity, specificity, and positive likelihood ratio were calculated by use of cutoffs determined from ROC curves or published reference limits.

RESULTS Considering preregenerative anemia as non regenerative, areas under the curve (AUCs) for reticulocyte percentage, number, and production index were 97%, 93%, and 91% for manual counting and 93%, 90%, and 93% for automated counting. Sensitivity, specificity, and positive likelihood ratio were 82% to 86%, 82% to 87%, and 4.6 to 6.4, respectively. Considering preregenerative anemia as regenerative, AUCs were 77%, 82%, and 80% for manual counting and 81%, 82%, and 92% for automated counting. Sensitivity, specificity, and positive likelihood ratio were 72% to 74%, 76 to 87%, and 2.7 to 6.2, respectively.

CONCLUSIONS AND CLINICAL RELEVANCE Whereas all reticulocyte parameters identified regeneration in anemic dogs, the performance of specific parameters was dependent on the method used. Findings suggested that lower cutoffs than published reference limits are preferred for reticulocyte number and production index and higher cutoffs are preferred for reticulocyte percentage. Reticulocyte production index may be useful when the pretest probability of regeneration is moderate.

Supplementary Materials

    • Supplementary Table S1 (PDF 119 kb)

Contributor Notes

Dr. Rossi's present address is College of Veterinary Medicine, School of Veterinary and Life Science, Murdoch University, Murdoch, WA 6150, Australia.

Address correspondence to Dr. Paltrinieri (saverio.paltrinieri@unimi.it).