Silvia Pipitone

Lack of harmonization of red blood cell distribution width (RDW). Evaluation of four hematological analyzers.

OBJECTIVES To assess analytical imprecision and comparability of red blood cell distribution width (RDW) on Abbott Sapphire, Mindray BC6800, Siemens Advia 2120 and Sysmex XE-5000. DESIGN AND METHODS Within-run imprecision was assessed on three pools and comparability using 132 inpatient samples. RESULTS The imprecision of RDW was comprised between 0.3 and 1.2%, but the values exhibited broad variation among different analyzers, with bias exceeding the desirable quality specifications. CONCLUSIONS Harmonization of RDW is still an unmet need.

Evaluation of mean platelet volume with four hematological analyzers: harmonization is still an unresolved issue.

The clinical applications of mean platelet volume (MPV) have recently broadened far beyond the differential diagnosis of platelet (PLT) disorders to embrace diagnosis and prognostication of a variety of thrombotic conditions. As the potential usefulness of this simple and inexpensive parameter may be challenged by instrument heterogeneity, we investigated the degree of analytical quality and interinstrument comparability. One hundred consecutive inpatient samples were simultaneously assessed on Abbott Sapphire, Mindray BC6800, Siemens Advia 2120, and Sysmex XE5000. The within-run imprecision of the four hematological analyzers was also assessed according to the Clinical and Laboratory Standards Institute document EP5-A2. The imprecision of PLT count ranged between 1.4 and 4.3%, and hence was always within the desirable quality specifications. The within-run imprecision of MPV ranged between 1.1 and 3.8%, and hence was also within the desirable quality specifications. The optical and impedance measurements displayed excellent correlations. Overall, the PLT count exhibited a modest instrumental variation, with bias always within the desirable quality specifications. A large bias was instead recorded for MPV, with between-instrument variations exceeding the desirable quality specifications in five out of six interinstrumental comparisons. No significant correlation was also observed between PLT count and MPV with any of the instruments tested. These results attest that although there is an optimal degree of analytical quality and comparability for PLT counting among different hemocytometers, the harmonization of MPV is poor, thus making the adoption of universal cutoffs virtually impossible.

Influence of in vitro hemolysis on hematological testing on Advia 2120

Introduction:  Although there is broad knowledge on the effect of several preanalytical errors on laboratory hematology, there is no information on the reliability of routine hematological testing on hemolyzed specimens.

Influence of residual platelet count on routine coagulation, factor VIII, and factor IX testing in postfreeze-thaw samples.

The use of frozen-thawed samples rather than fresh samples for specialized coagulation testing is becoming commonplace, thereby creating novel risks that may jeopardize the quality of hemostasis testing. Residual platelets (PLTs) in frozen plasma are most critical as freezing-induced activation and injury may impair routine and specialized testing after thawing. The aim of this study was to verify the impact of postcentrifugation PLT count in postfreeze-thawed samples on activated partial thromboplastin time (APTT), prothrombin time (PT), fibrinogen, factor VIII (FVIII) activity testing, and factor IX (FIX) activity testing. These parameters were herein assessed in postfreeze-thaw paired plasma samples collected from 15 healthy volunteers and subjected to 4 different centrifugation forces (i.e., 3,000, 1,500, 1,000, and 500g), using data obtained with centrifugation force of 1,500g as the gold standard, in agreement with current recommendations. Compared with reference samples, PLT counts in fresh aliquots were indistinguishable in specimens centrifuged at 1,000g, significantly lower in those centrifuged at 3,000g and significantly higher in those centrifuged at 500g. In all cases except samples centrifuged at 3,000g, the PLT count was significantly decreased in postfreeze-thaw compared with paired fresh specimens. In postfreeze-thaw plasma, APTT was not influenced by residual PLT count. The results of PT and fibrinogen were consistently altered in samples centrifuged at 1,000 and 500g, though the correlation with the reference measures remained clinically acceptable. Data obtained for FVIII and FIX activities revealed a positive bias in all postfreeze-thaw plasmas, achieving statistical significance in samples centrifuged at 3,000g. We conclude that alteration of centrifuge speeds away from the recommended 1,500g may influence the level of residual PLTs in sample centrifuged at lower speeds such as 500g, and therefore may make these specimens unsuitable for hemostasis testing in postfreeze-thawed plasma samples. In addition, although the changes seen in FVIII and FIX in samples centrifuged at 3,000g may reflect non-PLT-related effects, such changes should also be considered in this setting.

Evaluation of white blood cell count in peritoneal fluid with five different hemocytometers

OBJECTIVES Evaluation of automated flow cytometric analysis of white blood cell (WBC) count in peritoneal fluids. METHODS One hundred peritoneal fluids were analyzed with manual microscopy, Sysmex XE-2100 and XE-5000, Siemens Advia 2120, Mindray BC-6800, Abbott Sapphire. RESULTS High correlations (0.978 to 0.999) and modes biases (-132 to 80 WBC/mm(3)) were found. Agreement at septic peritonitis cutoff ranged between 96% and 99%. CONCLUSIONS These hemocytometers display acceptable performance for WBC screening in peritoneal fluids.

Assessment of neutrophil gelatinase-associated lipocalin and lactate dehydrogenase in peritoneal fluids for the screening of bacterial peritonitis

BACKGROUND Manual microscopy remains the gold standard for enumeration and classification of nucleated cells in peritoneal fluids, especially for diagnosing bacterial peritonitis. However, this approach carries several drawbacks, so that the use of simple and automated tests may be a viable option for initial screening of peritoneal fluids. MATERIALS AND METHODS Neutrophil gelatinase-associated lipocalin (NGAL), lactate dehydrogenase (LDH), proteins and glucose were assessed in peritoneal fluids from patients with new onset nonmalignant ascites, along with nucleated cell count and differentiation. RESULTS One hundred and eleven specimens were analyzed, 26 of which (23%) with polymorphonuclear leukocyte (PMN) count≥250/μL, thus compatible with bacterial peritonitis. The median concentration of LDH and NGAL was 3.4 and 3.7-fold higher in samples with ≥250 PMN/μL. The concentration of proteins was also higher in samples with ≥250 PMN/μL, whereas that of glucose was lower. The PMN count significantly correlated with peritoneal fluid values of LDH (r=0.859), NGAL (r=0.774) and proteins (r=0.268), but not with glucose (r=-0.069). The area under ROC curve was 0.88 for LDH, 0.89 for NGAL and 0.94 for their combination (both tests positive), whereas that of proteins and glucose was 0.80 and 0.71, respectively. Sensitivities and specificities were 0.81 and 0.87 for LDH≥227 U/L, 0.96 and 0.75 for NGAL≥120 ng/mL, 0.77 and 0.95 for their combination. The agreement with PMN count was 0.86 for LDH, 0.80 for NGAL, and 0.91 for their combination. CONCLUSIONS These results suggest that assessment of NGAL in peritoneal fluids, especially in combination with LDH, may be a reliable approach for screening of bacterial peritonitis in patients with new onset nonmalignant ascites.

Evaluation of the Fully Automated Hematological Analyzer Sysmex XE-5000 for Flow Cytometric Analysis of Peritoneal Fluid

Although microscopy still represents the gold standard for cytometric analysis of peritoneal fluids, automated flow cytometry may improve throughput and accuracy. We evaluated the performance of total nucleated cell (TNC), white blood cell (WBC), polymorphonuclear cell (PMN), and mononuclear cell (MONO) counts of Sysmex XE-5000 on peritoneal fluids. The imprecision was excellent, being always lower than 11%, whereas linearity studies yielded correlation coefficients of 1.00 for all parameters. The carryover was always lower than 0.2%. The comparison between XE-5000 and microscopic analysis of 117 ascitic fluids yielded correlation coefficients always greater than 0.96, with mean biases <11/µL. The diagnostic accuracy versus manual microscopy was greater than that of XE-2100, especially at thresholds for septic ascites (100 versus 98% for ≥500 WBC/µL; 98 versus 93% for ≥250 PMN/µL). The correlation with manual microscopy for macrophages and mesothelial cell count was also higher for XE-5000 than for XE-2100 (0.63 versus 0.55). The results of this evaluation show optimal performance of XE-5000 for routine analysis of ascitic fluids, which are combined with the advantages of automated analysis such as high throughout, shortened turnaround time, no need of sample preparation and trained staff, reduced sample volume, and less likelihood of transcriptional errors.

Preliminary evaluation of complete blood cell count on Mindray BC-6800.

*Corresponding author: Prof. Giuseppe Lippi, U.O. Diagnostica Ematochimica, Azienda Ospedaliero-Universitaria di Parma, Via Gramsci, 14, 43126 Parma, Italia, Phone: +39 0521 703050/ +39 0521 703197, E-mail: glippi@ao.pr.it; ulippi@tin.it Giuseppe Lippi, Clarissa Cattabiani, Mirco Bardi and Silvia Pipitone: Laboratory of Clinical Chemistry and Hematology, Academic Hospital of Parma, Parma, Italy Sabrina Bonomini and Franco Aversa: Hematology and BMT Center, University of Parma, Parma, Italy

In Vitro Blood Compatibility of Novel Hydrophilic Chitosan Films for Vessel Regeneration and Repair

In the vascular field, currently, the best graft performance is given by saphenous vein auto‐ grafts [1] whose main failures are related to thrombosis development, emboli production, and intimal hyperplasia. Synthetic non-bio-resorbable vascular prosthesis (such as Dacron® or extended-PTFE) exhibited very low incidences of thrombosis or hyperplasia and showed good clinical results in mediumand large-diameter graft sites.

Influence of temperature and period of freezing on the generation of hemolysate and blood cell lysate.

BACKGROUND There is little information on temperature and period of freezing for generating hemolysate and blood cell lysate. MATERIALS AND METHODS Primary tubes containing whole blood were frozen at -20°C and -80°C and then serially thawed to assess cell lysis and clinical chemistry tests in centrifuged plasma. RESULTS AND CONCLUSIONS Massive amount of blood cells lysis could only be obtained by storing samples 12h at -20°C, or 2h at -80°C.