International Journal of Laboratory Hematology The Official journal of the International Society for Laboratory Hematology
ORIGINAL ARTICLE
INTERNAT IONAL JOURNAL OF LABORATO RY HEMATO LOGY
Interference of blast cell fragments with automated platelet counting B. FROTSCHER* ,† , S. SALIGNAC*, M. MULLER* , ‡ , V. LATGER-CANNARD* , § , P. FEUGIER ¶ , J. F. LESESVE* , §
*Department of Laboratory Haematology, University Hospital of Nancy, Vandoeuvreles-Nancy, France † Haemophilia Treatment Centre, University Hospital of Nancy, Vandoeuvre-les-Nancy, France ‡ Laboratory of Genetics, University Hospital of Nancy, Vandoeuvre-les-Nancy, France § Flow Cytometry Plateform, University Hospital of Nancy, Vandoeuvre-les-Nancy, France ¶ Department of Clinical Haematology, University Hospital of Nancy, Vandoeuvreles-Nancy, France Correspondence: Birgit Frotscher, Laboratory of Haematology, Haemophilia Treatment Centre, University Hospital of Nancy, F-54511 Vandoeuvre-les-Nancy, France. Tel.: 0033-3-83 15 37 87; Fax: 0033-3-83 15 37 96; E-mail: b.frotscher@chu-nancy. fr
doi:10.1111/ijlh.12371
Received 9 November 2014; accepted for publication 3 March 2015
ABSTRACT Introduction: Automated haematology analysers may inaccurately determine platelet counts in several circumstances. Spuriously elevated automated platelet counts have been reported in some acute leukaemia (AL) cases because of fragmentation of circulating blast cells (pseudoplatelets). Haemorrhagic diathesis is a common manifestation of AL, which is often caused by severe thrombocytopenia. Therefore, overestimation of the actual platelet count in patients with AL can affect its clinical management. We aimed to detect the frequency of pseudoplatelets in patients with AL. Methods: Complete blood cell counts were performed on 86 AL patients with three automated analysers (ADVIA 2120, Coulter LH 750 and Sysmex XE-2100D). Platelet counts were also performed by quantitative flow cytometry (QFC). The platelet counts of the automatic analysers were compared to the platelet counts by QFC. Blood smears were checked for the presence of pseudoplatelets. Results: The automated analysers overestimated the platelet count due to the presence of pseudoplatelets in patients with AL. Pseudoplatelets were observed in the blood smears of 11 patients (13%). Three of these patients were near the prophylactic platelet transfusion threshold. Conclusion: Spurious increases in automated platelet counts by blast cell fragments are little known but frequent artefacts that should be ruled out by careful examination of peripheral blood smears.
Keywords Platelets, pseudoplatelets, automated blood cell counter, acute leukaemia, blast cell fragments
© 2015 John Wiley & Sons Ltd, Int. Jnl. Lab. Hem. 2015, 37, 613–619
613
614
B. FROTSCHER ET AL. | BLAST FRAGMENTS AND AUTOMATED PLATELETS COUNTS
INTRODUCTION Current haematology analysers provide fast and accurate platelet counts in most situations, even in the context of severe thrombocytopenia (
ORIGINAL ARTICLE
INTERNAT IONAL JOURNAL OF LABORATO RY HEMATO LOGY
Interference of blast cell fragments with automated platelet counting B. FROTSCHER* ,† , S. SALIGNAC*, M. MULLER* , ‡ , V. LATGER-CANNARD* , § , P. FEUGIER ¶ , J. F. LESESVE* , §
*Department of Laboratory Haematology, University Hospital of Nancy, Vandoeuvreles-Nancy, France † Haemophilia Treatment Centre, University Hospital of Nancy, Vandoeuvre-les-Nancy, France ‡ Laboratory of Genetics, University Hospital of Nancy, Vandoeuvre-les-Nancy, France § Flow Cytometry Plateform, University Hospital of Nancy, Vandoeuvre-les-Nancy, France ¶ Department of Clinical Haematology, University Hospital of Nancy, Vandoeuvreles-Nancy, France Correspondence: Birgit Frotscher, Laboratory of Haematology, Haemophilia Treatment Centre, University Hospital of Nancy, F-54511 Vandoeuvre-les-Nancy, France. Tel.: 0033-3-83 15 37 87; Fax: 0033-3-83 15 37 96; E-mail: b.frotscher@chu-nancy. fr
doi:10.1111/ijlh.12371
Received 9 November 2014; accepted for publication 3 March 2015
ABSTRACT Introduction: Automated haematology analysers may inaccurately determine platelet counts in several circumstances. Spuriously elevated automated platelet counts have been reported in some acute leukaemia (AL) cases because of fragmentation of circulating blast cells (pseudoplatelets). Haemorrhagic diathesis is a common manifestation of AL, which is often caused by severe thrombocytopenia. Therefore, overestimation of the actual platelet count in patients with AL can affect its clinical management. We aimed to detect the frequency of pseudoplatelets in patients with AL. Methods: Complete blood cell counts were performed on 86 AL patients with three automated analysers (ADVIA 2120, Coulter LH 750 and Sysmex XE-2100D). Platelet counts were also performed by quantitative flow cytometry (QFC). The platelet counts of the automatic analysers were compared to the platelet counts by QFC. Blood smears were checked for the presence of pseudoplatelets. Results: The automated analysers overestimated the platelet count due to the presence of pseudoplatelets in patients with AL. Pseudoplatelets were observed in the blood smears of 11 patients (13%). Three of these patients were near the prophylactic platelet transfusion threshold. Conclusion: Spurious increases in automated platelet counts by blast cell fragments are little known but frequent artefacts that should be ruled out by careful examination of peripheral blood smears.
Keywords Platelets, pseudoplatelets, automated blood cell counter, acute leukaemia, blast cell fragments
© 2015 John Wiley & Sons Ltd, Int. Jnl. Lab. Hem. 2015, 37, 613–619
613
614
B. FROTSCHER ET AL. | BLAST FRAGMENTS AND AUTOMATED PLATELETS COUNTS
INTRODUCTION Current haematology analysers provide fast and accurate platelet counts in most situations, even in the context of severe thrombocytopenia (
