Alexander Pankraz1, Natali Bauer, Andreas Moritz. 1. Department of Veterinary Clinical Sciences, Clinical Pathology and Clinical Pathophysiology, Justus-Liebig University Giessen, Giessen, Germany. alexander_pankraz@lycos.de
Abstract
BACKGROUND: Immature (reticulated) platelets (r-PLT) are not routinely assessed by hematology analyzers, but may be useful in the evaluation of the bone marrow response to thrombocytopenia. OBJECTIVE: The aim of this study was to compare the Sysmex XT2000iV hematology analyzer with standard flow cytometry for the determination of r-PLT percentage in dogs. METHODS: Blood samples were obtained from 40 healthy dogs, 12 thrombocytopenic dogs, and 6 dogs with normal platelet counts but with disorders associated with increased thrombopoiesis. The percentage of r-PLT was determined with a FACscan flow cytometer (r-PLT[F]) using CD61-phycoerythrin antibody and thiazole orange, and with the PLT-O channel of the Sysmex analyzer (r-PLT[S]). Mean platelet volume, platelet distribution width, and platelet large cell ratio were also determined on the Sysmex. Repeatability (intra-assay precision) and effect of storage were tested for the automated analyzer. RESULTS: The reference interval (mean+/-1.96 X SD) for r-PLT(F) was 1.91+/-1.29% (range 0.78-3.68%) and for r-PLT(S) was 0.56+/-0.82% (range 0.11-2.16%). For both flow cytometry and the Sysmex, the patient group had a significantly higher mean percentage of r-PLT compared with the control group (P<.0001, unpaired Student's t-tests). Fair correlation (r=0.71; Spearman's regression analysis) was found for r-PLT results between the 2 methods, and a negative proportional systematic bias of -6.26 was found for the Sysmex (Bland-Altman analysis). Based on receiver operating characteristic curves and a cut-off of > or =0.975%, a sensitivity of 94.7% and a specificity of 85.7% were obtained for detecting r-PLT on the Sysmex, using flow cytometry as the reference method. Blood samples stored at 4 degrees C and 25 degrees C had a significant increase in the percentage of r-PLT after 24 and 48 hours, respectively. CONCLUSIONS: The PLT-O channel of the Sysmex XT2000iV is capable of detecting immature platelets in healthy, thrombocytopenic, and non-thrombocytopenic ill dogs.
BACKGROUND: Immature (reticulated) platelets (r-PLT) are not routinely assessed by hematology analyzers, but may be useful in the evaluation of the bone marrow response to thrombocytopenia. OBJECTIVE: The aim of this study was to compare the Sysmex XT2000iV hematology analyzer with standard flow cytometry for the determination of r-PLT percentage in dogs. METHODS: Blood samples were obtained from 40 healthy dogs, 12 thrombocytopenicdogs, and 6 dogs with normal platelet counts but with disorders associated with increased thrombopoiesis. The percentage of r-PLT was determined with a FACscan flow cytometer (r-PLT[F]) using CD61-phycoerythrin antibody and thiazole orange, and with the PLT-O channel of the Sysmex analyzer (r-PLT[S]). Mean platelet volume, platelet distribution width, and platelet large cell ratio were also determined on the Sysmex. Repeatability (intra-assay precision) and effect of storage were tested for the automated analyzer. RESULTS: The reference interval (mean+/-1.96 X SD) for r-PLT(F) was 1.91+/-1.29% (range 0.78-3.68%) and for r-PLT(S) was 0.56+/-0.82% (range 0.11-2.16%). For both flow cytometry and the Sysmex, the patient group had a significantly higher mean percentage of r-PLT compared with the control group (P<.0001, unpaired Student's t-tests). Fair correlation (r=0.71; Spearman's regression analysis) was found for r-PLT results between the 2 methods, and a negative proportional systematic bias of -6.26 was found for the Sysmex (Bland-Altman analysis). Based on receiver operating characteristic curves and a cut-off of > or =0.975%, a sensitivity of 94.7% and a specificity of 85.7% were obtained for detecting r-PLT on the Sysmex, using flow cytometry as the reference method. Blood samples stored at 4 degrees C and 25 degrees C had a significant increase in the percentage of r-PLT after 24 and 48 hours, respectively. CONCLUSIONS: The PLT-O channel of the Sysmex XT2000iV is capable of detecting immature platelets in healthy, thrombocytopenic, and non-thrombocytopenic illdogs.
Authors: Dana E Oellers; Natali Bauer; Melanie Ginder; Sigrid Johannes; Iris Pernecker; Andreas Moritz Journal: BMC Vet Res Date: 2016-07-22 Impact factor: 2.741