Cosimo Ottomano

Inflammation and thrombosis in essential thrombocythemia and polycythemia vera: different role of C-reactive protein and pentraxin 3

We tested the hypothesis that levels of pentraxin high sensitivity C-reactive protein and pentraxin 3 might be correlated with cardiovascular complications in patients with essential thrombocythemia and polycythemia vera. High sensitivity C-reactive protein and pentraxin 3 were measured in 244 consecutive essential thrombocythemia and polycythemia vera patients in whom, after a median follow up of 5.3 years (range 0–24), 68 cardiovascular events were diagnosed. The highest C-reactive protein tertile was compared with the lowest (>3 vs. <1 mg/L) and correlated with age (P=0.001), phenotype (polycythemia vera vs. essential thrombocythemia, P=0.006), cardiovascular risk factors (P=0.012) and JAK2V617F allele burden greater than 50% (P=0.003). Major thrombosis rate was higher in the highest C-reactive protein tertile (P=0.01) and lower at the highest pentraxin 3 levels (P=0.045). These associations remained significant in multivariate analyses and indicate that blood levels of high sensitivity C-reactive protein and petraxin 3 independently and in opposite ways modulate the intrinsic risk of cardiovascular events in patients with myeloproliferative disorders.

Laboratory network of excellence: enhancing patient safety and service effectiveness

Abstract Clinical laboratories have undergone major changes due to technological progress and economic pressure. While costs of laboratory testing continue to be the dominant issue within the healthcare service worldwide, quality, effectiveness and impact on outcomes are also emerging as critical value-added features. Five Italian laboratories are therefore promoting a network of excellence by investigating markers of effectiveness of laboratory services and sharing their experience of using them in clinical practice. In the present study we report preliminary data on indicators of quality in all phases of the so-called total testing process, the key to evaluating all phases of the total testing process, including the appropriateness of test requests and data interpretation. Initial findings in evaluating pre-analytical causes of specimen rejection in three different laboratories and the effects of introducing three laboratory clinical guidelines are reported. These data should stimulate debate in the scientific community and encourage more clinical laboratories to use the same indicators to improve clinical effectiveness and clinical outcomes within the healthcare service.

JAK2V617F mutation and hydroxyurea treatment as determinants of immature platelet parameters in essential thrombocythemia and polycythemia vera patients

Immature platelets (IPFs), which are hemostatically more active than mature platelets, have been found elevated in essential thrombocythemia and polycythemia vera, 2 myeloproliferative neoplasms (MPN) characterized by an increased risk of thrombosis. It is not known whether the IPF levels are influenced by pathogenetic factors, including JAK2V617F mutational status, or by treatment regimen. To address this point, in 46 essential thrombocythemia and 38 polycythemia vera consecutive patients, we measured IPF and correlated the results to JAK2V617F mutation and myelosuppressive treatment with hydroxyurea. This analysis provides 2 new elements regarding IPF and MPN. The first finding is that the JAK2V617F mutation is linked to the quantity of IPF in patients with MPN, which might contribute to the prothrombotic phenotype in these patients. The second finding is that IPF is susceptible to myelosuppressive treatment, which may additionally explain the favorable effect of hydroxyurea therapy on MPN outcome as well as the associated thrombotic risk.

Process and risk analysis to reduce errors in clinical laboratories

Abstract Background: An important point in improving laboratory quality is the definition of some indicators to be monitored as measures of a laboratory trend. The continuous observation of these indicators can help to reduce errors and risk of errors, thus enhancing the laboratory outcome. In addition, the standardization of risk evaluation techniques and the definition of a set of indicators can eventually contribute to a benchmarking process in clinical laboratories. Methods: Five Italian hospital laboratories cooperated in a project in which methodologies for process and risk analysis, usually applied in fields other than healthcare (typically aeronautical and transport industries), were adapted and applied to laboratory medicine. The collaboration of a board of experts played a key role in underlining the limits of the proposed techniques and adapting them to the laboratory situation. A detailed process analysis performed in each center was the starting point, followed by risk analysis to evaluate risks and facilitate benchmarking among the participants. Results and conclusions: The techniques applied allowed the formulation of a list of non-conformities that represented risks of errors. The level of risk related to each was quantified and graphically represented for each laboratory to identify the risk area characteristic for each of the centers involved. Clin Chem Lab Med 2007;45:742–8.

Analytical evaluation of Sysmex UF-1000i for flow cytometric analysis of peritoneal fluid

OBJECTIVE To evaluate analytical performance of Sysmex UF-1000i for peritoneal fluid analysis. METHODS Functional sensitivity, imprecision, linearity and comparison studies were performed on peritoneal fluids. RESULTS Total imprecision was 1.6-4.7%, functional sensitivity 27/μL for white blood cell (WBC) and 32/μL for total nucleated cell (TNC) count. Linearity was excellent up to 983 cell/μL, carry-over <0.2%, correlation with manual microscopy always greater than 0.992. CONCLUSION The instrument exhibited optimal performance at the conventional WBC diagnostic thresholds.

Mid-stream vs. first-voided urine collection by using automated analyzers for particle examination in healthy subjects: an Italian multicenter study

Abstract Background: In analogy with other areas of laboratory diagnostics, the pre-analytical phase is the leading source of variability also in urinalysis. We carried out a multicentric study for comparing results obtained from first-voided and mid-stream urine samples. Methods: Each of the six hospital-based clinical laboratories participating to this study recruited 50 healthy subjects among laboratory staff and/or their relatives. Two consecutive samples of the first morning micturition were collected by vacuum system, the first from the first-void and the second from the mid-stream. Routine urinalysis was performed using dip-stick automated analyzers for chemical examination and automated analyzers for formed particle examination (Sysmex UF-100, Sysmex UF-1000i and Iris iQ-200). Results: Counts of epithelial cells (EC), erythrocytes (ERY) and leukocytes (LEU) but not for cylinders (CAS) were significantly higher in the first-voided samples. A significantly higher count of EC, ERY and LEU was also observed between females and males in first-voided samples, whereas no significant difference could be found in mid-stream samples. Health related analyzer specific upper reference limits (URL) were CAS≤1, EC≤5, ERY≤19, Leu≤13 for UF-100; CAS≤1, EC≤4, ERY≤15, Leu≤11 for UF-1000i; CAS≤1, EC≤4, ERY≤18, Leu≤10 for iQ200. The overall prevalence of subjects with cellular elements count exceeding URL was also higher in first-voided than in mid-stream samples. Conclusions: Mid-stream urine was confirmed as the most appropriate sample, since the presence of contaminating elements, such as bacteria, analytes and formed particles are minimized.

PATHFAST NT-proBNP (N-terminal-pro B type natriuretic peptide): a multicenter evaluation of a new point-of-care assay.

Abstract Background: The biochemical determination of cardiac natriuretic peptides, primarily brain natriuretic peptide (BNP) and the amino-terminal fragment of its pro-hormone proBNP (NT-proBNP), are reliable tools for diagnosing cardiac disease, establishing prognosis and evaluating the effectiveness of treatment. These biomarkers have proven to be of particular value in the management of chronic and acute heart failure patients, and in the outpatient and the emergency setting. Methods: A multicenter evaluation was performed to assess the practicability, and the analytical and clinical performance of a new point-of-care testing (POCT) PATHFAST™ NT-proBNP assay. This is an immunochemiluminescent assay using two polyclonal antibodies in a sandwich test format, and performed with a PATHFAST™ automated analyzer. Results: The limit of detection (mean+3 SD of the signal of 20 replicates of the zero calibrator obtained in one run) was 0.535 ng/L. An imprecision study, performed in accordance with the CLSI protocol, showed coefficients of variation of 4.0%–6.4% (within-run imprecision), 0.0%–3.4% (between-run imprecision), 5.5%–7.2% (between-day imprecision), 7.6%–8.9% (total imprecision). The method was linear to 28,755 ng/L. Slopes and intercepts ranged from 0.89 to 0.90 and from 10.96 to 22.85, respectively when lithium-heparin plasma samples (n=100) were used to compare the assay under evaluation with the routine laboratory methods (Dimension RxL®, Stratus® CS). When testing matched samples (n=52), a significant difference was found between the 50th percentile NT-proBNP concentration in K2EDTA whole blood, K2EDTA plasma, lithium-heparin plasma and serum. No significant interference was observed for NT-proBNP in lipemic (tryglicerides up to 28.54 mmol/L), icteric (total and conjugated bilirubin up to 513 and 13 μmol/L, respectively) or hemolyzed (hemoglobin up to 13.50 g/L) samples. The NT-proBNP concentration in a group of 180 healthy donors was significantly influenced by age and gender. In a selected population of patients (n=56) with acute dyspnea admitted to the emergency department, a marked reduction in cardiac natriuretic peptide concentrations was observed in hospitalized patients suffering from heart failure who had a better prognosis compared with those with a poorer prognosis (NT-proBNP mean Δ change, % from –22 to –71 vs. +9 to –11). Conclusions: The satisfactory analytical and clinical performance of the PATHFAST™ NT-proBNP assay, together with its excellent practicability, suggests that it would be a reliable tool in clinical practice, in the emergency setting for point-of-care testing, as well as in the central laboratory. Clin Chem Lab Med 2010;48:1029–34.

Cell Population Data and reflex testing rules of cell analysis in pleural and ascitic fluids using body fluid mode on Sysmex XN-9000

BACKGROUND Although optical microscopy (OM) remains the reference technique for analysis of ascitic (AF) and pleural (PF) fluids, novel hematological analyzers are equipped with modules for body fluid (BF) analysis. This study was aimed to analyze the performance of XN-BF module in Sysmex XN-9000, and to develop validation rules for automated cell counts in BFs. METHODS The evaluation of XN-BF module included assessment of carryover, Limit of Blank (LoB), Limit of Detection (LoD), Limit of Quantitation (LoQ), linearity, data comparison with OM, and development of rules for assisting the validation of automated analysis of BFs and activating reflex testing. RESULTS The carryover was negligible. The LoB, LoD, LoQ and linearity were always excellent. The comparison with OM was characterized by Pearsons correlations ranging from r=0.50 to r=0.99 (p<0.001), modest bias and high diagnostic concordance (Area Under the Curve between 0.85 and 0.99). The use of instrument-specific cut-offs further increased diagnostic concordance. The implementation of reflex testing rules based on XN-BF data increased sensitivity and specificity of BFs classification to 0.98 and 0.95. CONCLUSIONS Our results suggest that the XN-BF module on Sysmex-9000 may be a suitable alternative to OM for screening BF samples, especially when specific validation rules are used.

Biological variation of platelet parameters determined by the Sysmex XN hematology analyzer

BACKGROUND This study was aimed to define the short- and medium-term biological variation (BV) estimates, the index of individuality and the reference change value (RCV) of platelet count, platelet distribution width, mean platelet volume, platelet larger cell ratio, plateletcrit and immature platelet fraction. METHODS The study population consisted of 43 health subjects, who participated to the assessment of medium-term (21 subjects; blood sampling once a week for 5 consecutive weeks) and short-term (22 subjects; blood sampling once a day for 5 consecutive days) BV study, using Sysmex XN-module. Eight subjects were also scheduled to participate to both phases. The data were subject to outlier analysis prior to CV-ANOVA, to determine the BV estimates with the relative confidence intervals. RESULTS The medium-term and short-term within-subject BV (CVI) was comprised between 2.3 and 7.0% and 1.1-8.6%, whereas the medium-term and short-term between-subjects BV (CVG) was comprised between 7.1 and 20.7% and 6.8-48.6%. The index of individuality and index of heterogeneity were always respectively <0.6 and >0.63 for all the parameters, in both arms of the study. The RCVs were similar for all parameters, in both arms of the study. CONCLUSION This study allowed to define the BV estimates of many platelet parameters, some of them unavailable in literature. The kinetics of platelet turnover suggests the use of short-term BV data for calculating analytical goals and RCV. The correct clinical interpretation of platelet parameters also necessitates that each laboratory estimates local RCV values.

Reflex Testing Rules for Cell Count and Differentiation of Nucleated Elements in Pleural and Ascitic Fluids on Sysmex XE-5000

Flow cytometry is widely used in many laboratories for automated nucleated cell counts and their differentiation in body fluids. The implementation of new reflex testing rules on these automated instruments could open new frontiers in laboratory workflow, improving characterization of body fluids and clinical diagnosis and decreasing costs. Ascitic (150) and pleural (33) fluids were collected and assessed by XE-5000 and optical microscopy. Cell counts performed with the methods showed a Pearson’s correlation of 0.98 (p < 0.0001), Passing–Bablok regression y = 0.99x + 2.44, and bias of 32.3. In ascitic fluids, the best diagnostic performance was found for polymorphonuclear and neutrophil counts on XE-5000, which exhibited areas under the curve (AUCs) 0.98 (p < 0.0001) and 0.99 (p < 0.0001), respectively. In pleural fluids the best diagnostic performance was found for polymorphonuclear percent parameter, which displayed 0.97 (p < 0.0001). Specific reflex test rules based on these parameters were characterized by 92% diagnostic concordance, 1.00 sensitivity, and 0.84 specificity with optical microscopy. The application of a set of reflex testing rules may improve the diagnostic performance of XE-5000, increasing its reliability for routine automated cell count in body fluids. We acknowledge that further studies should be planned to validate our findings according to clinical data.