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Introduction: Digital morphology analyzers are increasingly replacing light microscopy in laboratory hematology practice. This study aimed to perform the analytical validation of the white blood cell (WBC) differential and of reliability of platelet assessment on Sysmex DI-60 (Kobe, Japan). Methods: Validation included determination of within-run and between-run precision for WBC differential according to the CLSI EP15-A3 protocol, accuracy and method comparison with light microscopy and with the automated WBC differential from the Sysmex XN-10 hematology analyzer, reliability of platelet clump detection and platelet count estimation. Results: Standard deviations of both pre- and post-classification mostly satisfied manufacturer's criteria for imprecision. Accuracy assessment revealed that only eosinophil count (1.4%) in one peripheral blood smear (PBS) remained outside the declared range (2-10%) after reclassification. Method comparison between DI-60 and light microscopy yielded Spearman's correlation coefficients from 0.37 (basophils) to 0.94 (neutrophils and lymphocytes), minor proportional difference for bands, constant difference for monocytes, both constant and proportional difference for lymphocytes and statistically significant biases for bands, lymphocytes, monocytes and basophils. Diagnostic sensitivity (Se) and specificity (Sp) of DI-60 in detecting immature/pathological cells were 88.7% (95%CI:81.1-94.0) and 83.0% (95%CI:78.7-86.7), respectively, with the area under the curve (AUC) of 0.86 (95%CI:0.82-0.89). Agreement in detection of platelet clumps was 94.8% (kappa coefficient = 0.67, 95%CI:0.53-0.80). Se and Sp of DI-60 to detect platelet clumps were 65.7% (95%CI: 47.8- 80.9) and 96.9% (95%CI: 93.9-98.6), respectively, while AUC was 0.81 (95%CI: 0.76-0.86). Conclusion: DI-60 provides reliable WBC differential and platelet assessment. In doubtful cases, the use of light microscopy is still mandatory.

In the COVID-19 pandemic, we have witnessed an impressive speed in the development of effective vaccines approved for human use, based on clinical studies comparing their efficacy to placebo. A head-to-head comparison of the neutralizing antibody (NAb) responses elicited by four vaccines used in Europe during 2021 (BNT162b2, mRNA-1273, ChAdOx nCoV-19, Ad26.COV2.S) and their comparison to NAb responses in convalescents showed that while the amount was comparable, NAbs induced by natural infection were of superior quality. The highly scattered immune responses elicited by the four vaccines were equalled by booster mRNA vaccination, reaching the highest, plateau level of NAb at the population level. Equally high NAbs were induced in convalescents after a single injection of either vaccine. The use of wild-type virus as a challenge in the NAb determination revealed that NAbs produced by disease were better activators of the complement system than NAbs induced by vaccination. The contribution of spike protein-specific IgGs to the SARS-CoV-2 neutralization was lower in convalescents compared to vaccinees, indicating that those who recovered from COVID-19 were armed with antibodies of additional specificities and/or classes that contributed to virus neutralization. Such findings point to the need to re-examine the correctness of certain epidemiological measures applied in the current epidemic. We also highlight the importance of a standardized approach in assessing humoral immunity by the usage of the most comprehensive assays as early as possible in future epidemics.

Objectives Analytical validation of automated erythrocyte sedimentation rate (ESR) analyzers is necessary prior to their implementation into routine practice. Our aim was to perform the analytical validation of the modified Westergren method applied on the CUBE 30 touch analyzer (Diesse, Siena, Italy). Methods Validation included determination of within-run and between-run precision following the Clinical and Laboratory Standards Institute EP15-A3 protocol, comparison with the reference Westergren method, sample stability assessment at both room temperature and 4 °C, after 4, 8 and 24-h storage, and checking the extent of hemolysis and lipemia interference. Results Coefficients of variation (CVs) for within-run precision were 5.2% for the normal and 2.6% for the abnormal range, while between-run CVs were 9.4 and 2.2%, respectively. Comparison with the Westergren method (n=191) yielded Spearman’s correlation coefficient of 0.93, no constant nor proportional difference [y=0.4 (95% CI: −1.7–1.0) + 1.06 (95% CI: 1.00–1.14)x] and a non-significant mean absolute bias of −2.6 mm (95% CI: −5.3–0.2). Lower comparability was evidenced with increasing ESR values, with both constant and proportional differences for ESR values between 40 and 80 mm, and above 80 mm. Sample stability was not compromised up to 8-h storage both at room temperature (p=0.054) and 4 °C (p=0.421). Hemolysis did not affect ESR measurement up to 1.0 g/L of free hemoglobin (p=0.089), while lipemia index above 5.0 g/L affects the ESR result (p=0.004). Conclusions This study proved that CUBE 30 touch provides reliable ESR measurement and satisfactory comparability with the reference Westergren methods, with minor variation related to methodological differences.

In the COVID-19 pandemic, we witnessed an impressive speed in the development of effective vaccines that have been approved for use in humans on the basis of the clinical studies comparing their efficacy to placebo. Head-to-head comparisons of several approved vaccines are rare, as well as comparisons of immune responses generated by vaccination to the ones created by the disease. Due to lack of appropriate standardization of assays that evaluate immune response, it is difficult to compare results from different studies. However, such analyses are inevitable in order to properly assess the correctness of epidemic measures applied in an effort to combat the pandemic. Here we report on a head-to head comparison of the first four vaccines authorized for emergency use in Europe (BNT162b2, mRNA-1273, AZD1222 or Ad26.COV2.S) in their ability to induce neutralizing antibody response (NT). All four deliver genetic information for the full-length spike protein into the host cells and induce both humoral and cellular branch of spike-specific immune response. Thus, NT response could serve as an indicator of the quality of the overall immune response induced by these vaccines. Well standardized wild-type neutralization assay1 enabled reliable comparison of antibody response induced by vaccines to the response induced in convalescents. By analysing the response in 113 vaccinees (≥18 per vaccine) we observed that the highest NTs were induced by mRNA vaccines, followed by AZD1222 and finally Ad26.COV2.S. In comparison to convalescents, these NTs were significantly higher, comparable and significantly lower, respectively. NT decline was significantly slower in convalescents. Better complement-activating properties of antibodies developed in natural infection as well as lower anti-spike IgG content in convalescents’ in comparison to vaccinees’ sera of comparable SARS-CoV-2 neutralisation power indicate that convalescents are armed with antibodies of additional specificities and/or classes, that contribute to SARS-CoV-2 neutralisation. 1Ravlić et al. Front. Immun. 2022 ; https://doi.org/10.3389/fimmu.2022.816159

Introduction The aim of this study was to screen practices used in verification procedures for methods/analysers among medical biochemistry laboratories (MBLs) in Croatia. We hypothesized that these procedures differ widely from laboratory to laboratory and wanted to gather specific data on steps used in the verification workflow. Materials and methods In order to obtain data, an online survey was conducted. The survey, divided in two sections, contained 29 questions and statements addressing general characteristics and specific steps of the verification workflow of each individual MBL. The survey was disseminated among managers of all MBLs in Croatia. Results A total of 108/196 (55%) laboratories participated in the survey. Forty nine MBLs were excluded from the second part of the survey: 14 have not implemented verification procedures, and 35 MBLs due to the absence of answers. The most relevant results of the second part of the survey showed that: 18/59 (0.31) of the responding MBLs have difficulties when defining acceptance criteria, 27/59 (0.46) used the Clinical and Laboratory Standards Institute protocol for precision estimation ; the majority of MBLs used a median of 20 samples for method/analyser comparisons and estimated bias using internal quality control samples ; reference intervals provided by external sources are mainly adopted ; 60% of MBLs do not include linearity verification in their protocol and do not use the national document for the estimation of measurement uncertainty. Conclusions Heterogeneous verification protocols are routinely utilized across Croatian MBLs which clearly confirms that a national document might help in the harmonization of verification procedures.

In the COVID-19 pandemic, we witnessed an impressive speed in the development of effective vaccines that have been approved for use in humans on the basis of the clinical studies comparing their efficacy to placebo. Head-to-head comparisons of several approved vaccines are rare, as well as comparisons of immune responses generated by vaccination to the ones created by the disease. Due to lack of appropriate standardization of assays that evaluate immune response, it is difficult to compare results from different studies. However, such analyses are inevitable in order to properly assess the correctness of epidemic measures applied in an effort to combat the pandemic. Here we report on a head-to head comparison of the first four vaccines authorized for emergency use in Europe (BNT162b2, mRNA-1273, AZD1222 or Ad26.COV2.S) in their ability to induce neutralizing antibody response (NT). All four deliver genetic information for the full-length spike protein into the host cells and induce both humoral and cellular branch of spike protein-specific immune response. Thus, NT response could serve as an indicator of the overall immune response induced by these vaccines. Well standardized wild-type neutralization assay1 enabled reliable comparison of antibody response induced by vaccines to the response induced in convalescents. By analysing the response in 113 vaccinees (≥18 per vaccine) we observed that the highest NTs were induced by mRNA vaccines, followed by AZD1222 and finally Ad26.COV2.S. In comparison to convalescents, these NTs were significantly higher, comparable and significantly lower, respectively. NT decline was significantly slower in convalescents. Better complement-activating properties of antibodies developed in natural infection as well as lower anti-spike IgG content in convalescents’ in comparison to vaccinees’ sera of comparable SARS-CoV-2 neutralisation power indicate that convalescents are armed with antibodies of additional specificities and/or classes, that contribute to SARS-CoV-2 neutralisation.

Background: Concomitant presence of lupus anticoagulant (LA) and monoclonal immunoglobulin in the same patient is uncommon and the influence of this finding on coagulation results is still unknown. Case report: We present a patient with a diagnosis of systemic lupus erythematosus (SLE) and secondary antiphospholipid syndrome (APS) with permanently positive LA who presented with accidental finding of newly discovered monoclonal IgM in a high concentration and dramatically prolonged prothrombin time (PT) and activated partial thromboplastin time (aPTT), without bleeding manifestations. Conclusion: Concomitant presence of extremely prolonged PT and aPTT with unusual coagulation reaction kinetics, consistent LA ratio over the follow-up period and normalization of coagulation screening results with decreasing monoclonal IgM concentration elicited suspicion that PT and aPTT prolongation could be attributed to M−protein with antiphospholipid specificity. Low LA-sensitive aPTT reagent Actin FS demonstrated exceptional sensitivity, whereas human placental thromboplastin in contrast to recombinant reagents showed significantly lower sensitivity to monoclonal IgM with antiphospholipid specificity. Changes in the activity of SLE observed during the follow-up period were inversely related to monoclonal IgM concentration, while the presence of secondary APS was consistent. Described analytical interference on PT and aPTT without bleeding manifestation should point towards suspicion of previously unidentified monoclonal IgM with antiphospholipid sensitivity.

Introduction Traditionally used laboratory methods do not always accurately reflect bleeding severity in hemophilia A (HA) patients. The ability of three global assays for identifying patients with unexpected bleeding phenotype was investigated. Methods Overall hemostasis potential (OHP), aPTT-clot waveform analysis (aPTT-CWA), endogenous thrombin potential (ETP), FVIII activities, and prothrombin fragment 1 + 2 concentrations were measured in 62 HA patients (30 severe and 32 non-severe) and 27 male controls. Bleeding phenotype was determined using our proposed scoring system including age at first joint bleed, number of target joints, and number of joint/muscle bleeds per year. Bleeding score ≤ 4 defined patients with mild bleeding phenotype (N = 27); score ≥ 5 defined severe bleeding phenotype (N = 35). Results The receiver operating characteristic analysis performed for distinguishing patients with severe and mild bleeding phenotype yielded following values of area under the curve: 0.910 (FVIII); 0.891 (aPTT-CWA parameter DELTA); 0.769 (OHP); and 0.634 (ETP). Unexpected bleeding phenotype was identified in 11/62 HA patients: 8/32 (25%) non-severe HA patients had severe, while 3/30 (10%) severe HA patients had mild bleeding phenotype, and global assays enabled the identification of all these patients. OHP and DELTA were revealed as the most reliable parameters for bleeding phenotype determination (10/11 and 9/11 unexpected results, respectively). Conclusion This study emphasizes OHP and aPTT-CWA as a powerful laboratory diagnostic tool in identifying HA patients with unexpected bleeding presentations, with the best results achieved by combining both assays. Global assays should not completely replace FVIII activity measurement but should be a part of the HA diagnostic algorithm.

Background: Carbohydrate sulfotransferases (CHST) were shown to be involved in carcinogenesis. The aim of the study was to assess the diagnostic value of serum CHST7 concentration in differentiation between lung cancer and non-malignant pulmonary inflammations. Methods: Clinical case-control study involving 125 participants was conducted: the control group containing cases of pneumonia and chronic obstructive pulmonary disease was compared to the lung cancer group composed of primary and metastatic cancers. Serum concentrations of CHST7 and routinely used markers including carcinoembryonic antigen (CEA), cytokeratin fragment 21-1 (CYFRA 21-1) and neuron-specific enolase (NSE) were determined for each participant using immunochemical methods. Statistical association, receiver operating characteristic (ROC) analysis and cross-validation were used for the evaluation of CHST7 either as a standalone biomarker or as a part of a biomarker panel. Results: In comparison to the control group, serum CHST7 was elevated in lung cancer (p Conclusions: Serum CHST7 is a promising biomarker for the differentiation between lung cancer and non-malignant pulmonary inflammations.

Introduction iSED is an alternate automated analyzer for erythrocyte sedimentation rate (ESR) based on photometric rheology technology that estimates ESR by measuring rouleaux formation. The aim was to evaluate the analytical performance of the iSED analyzer and compare the results with the Westergren method and another alternate ESR analyzer, TEST1. Methods Validation was performed at two study sites according to the recommendations by the International Council for Standardization in Haematology and included determination of intrarun precision and inter-run precision, bias, carryover, and method comparison, which was further assessed for samples with normal and low hematocrit, as well as per low, middle, and upper third of the analytical range. Results Intrarun coefficients of variation (CVs) with commercial controls were 4.0% and 1.8%, while inter-run CVs 7.5% and 0.7%, for the normal and pathological range, respectively. Intrarun CVs obtained with patient samples were 19.9%, 9.9%, 10.3%, and 9.4%, the highest being for the lowest ESR value. Correlation coefficients for the comparison between iSED and Westergren were 0.862 (Site-1) and 0.916 (Site-2). While proportional difference with a positive bias was revealed at Site-1, comparison at Site-2 showed both constant and proportional difference and a negligible negative bias. Higher correlation was obtained for samples with low than normal hematocrit. Comparison between iSED and TEST1 yielded a correlation coefficient of 0.986, constant and proportional difference, and positive bias. Carryover was 3.2%. Conclusion This study proved the analytical validity of the iSED analyzer, despite minor discrepancies to the Westergren method that can be attributed to methodological differences.

Aim To assess the role of human platelet antigens (HPA), P-selectin gene (SELP) polymorphisms, and HPA and SELP haplotypes with factor V (FV) R506Q in ischemic pediat - ric stroke (IPS) subtypes: cerebral sinovenous thrombosis (CSVT), perinatal (PAIS), and childhood (CAIS) arterial isch - emic stroke. Methods This case-control study enrolled 150 children with confirmed IPS and 150 age- and sex-matched con - trols. FV R506Q and HPA-1 were genotyped with CVD Stri - pAssay®, HPA-2 and HPA-3 with real-time polymerase chain reaction, SELP S290N, V599L, and T715P with high resolu - tion melting analysis, and SELP N562D with sequence-spe - cific polymerase chain reaction. Results HPA-1b allele (odds ratio [OR] 2.75, 95% confidence interval [CI] 1.02-7.42, P =0.048) and HPA-1a2a3b (OR 5.46, 95% CI 1.51-19.76, P =0.011), HPA-1b2a3a (OR 7.00, 95% CI 1.25-39.13, P =0.028), and HPA-1b2b3a (OR 11.39, 95% CI 1.39-92.95, P =0.024) haplotypes increased the risk for CSVT. HPA-3b allele was significantly associated with 2-fold lower risk for PAIS (OR 0.49, 95% CI 0.26-0.89, P =0.020) and CAIS (OR 0.47, 95% CI 0.26-0.86, P =0.014) and non-signifi - cantly associated with increased risk for CSVT (OR 6.43, 95% CI 0.83-50.00, P =0.022). HPA-1a2b3a haplotype was significantly associated with CAIS (OR 6.76, 95% CI 2.13-21.44, P=0.001). The inclusion of FV R506Q in SELP haplotype analysis increased the risk for PAIS 4-fold in QNDVT carri - ers (OR 8.14, 95% CI 0.93-71.33, P =0.060) compared with NDVT haplotype (OR 2.45, 95% CI 0.98-6.18, P =0.058), but the result was not significant. Conclusion Individual HPAs, and particularly HPA haplo - types, are involved in IPS subtypes pathogenesis. A possi - ble risk-inducing synergistic effect of SELP haplotypes with FV R506Q is restricted to PAIS only.

The aim of the study was to assess sleep architecture and breathing in sleep in children with Down syndrome. The study was conducted by using overnight video-polysomnography (V-PSG) in children with Down syndrome and age-matched children from the general population. Analysis of polysomnographic parameters revealed that compared to the norms of healthy age- and maturitymatched children from the general population, children with Down syndrome had significantly shorter sleep latency (p=0.007), shorter total sleep time (p=0.004), lower sleep efficiency (p=0.010), less NREM1 sleep phase (p=0.0002), less NREM3 sleep phase (p=0.034), less REM sleep (p=0.034) in favour of more NREM2 phase but not significantly (p=0.069), and spent more time awake after sleep onset (p=0.0002). Children with Down syndrome had significantly more obstructive sleep apnoeas and hypopnoeas per hour (higher obstructive sleep apnoeas and hypopnoeas index) (p=0.008), but less central sleep apnoea per hour (lower central apnoeas index) (p=0.041), which led to the nonsignificantly lower total apnoea- hypopnoea index (p=0.762) in children with Down syndrome. The mean and longest apnoea duration did not differ significantly between these two groups. Children with Down syndrome had a significantly lower mean and nadir oxygen saturation (p=0.008 and p=0.001, respectively). In conclusion, the majority of respiratory complications in children with Down syndrome can be prevented by raising awareness of sleep disturbances in children with Down syndrome among their parents and health care providers and by introducing early routine V-PSG in the follow up of these children.

The aim of the study was to assess sleep architecture and breathing in sleep in children with Down syndrome. The study was conducted by using overnight video-polysomnography (V-PSG) in children with Down syndrome and age-matched children from the general population. Analysis of polysomnographic parameters revealed that compared to the norms of healthy age- and maturitymatched children from the general population, children with Down syndrome had significantly shorter sleep latency (p=0.007), shorter total sleep time (p=0.004), lower sleep efficiency (p=0.010), less NREM1 sleep phase (p=0.0002), less NREM3 sleep phase (p=0.034), less REM sleep (p=0.034) in favour of more NREM2 phase but not significantly (p=0.069), and spent more time awake after sleep onset (p=0.0002). Children with Down syndrome had significantly more obstructive sleep apnoeas and hypopnoeas per hour (higher obstructive sleep apnoeas and hypopnoeas index) (p=0.008), but less central sleep apnoea per hour (lower central apnoeas index) (p=0.041), which led to the nonsignificantly lower total apnoea-hypopnoea index (p=0.762) in children with Down syndrome. The mean and longest apnoea duration did not differ significantly between these two groups. Children with Down syndrome had a significantly lower mean and nadir oxygen saturation (p=0.008 and p=0.001, respectively). In conclusion, the majority of respiratory complications in children with Down syndrome can be prevented by raising awareness of sleep disturbances in children with Down syndrome among their parents and health care providers and by introducing early routine V-PSG in the follow up of these children., Cilj: Istražiti arhitektoniku spavanja i disanja tijekom sna u djece s Downovim sindromom. Metode: Cjelonoćna videopolisomnografija (V-PSG) u skupini djece s Downovim sindromom i u onoj iz opće populacije odgovarajuće dobi i zrelosti. Rezultat: Analiza polisomnografskih parametara pokazala je da djeca s Downovim sindromom, u usporedbi s normativima u zdrave djece u općoj populaciji, odgovarajuće dobi i zrelosti, imaju značajno kraću latenciju spavanja (SL) p=0,007, kraće ukupno vrijeme spavanja (TST) p=0,004, nižu efikasnost spavanja (SE) p=0,010, manje NREM1 faze spavanja p=0,0002, manje NREM3 faze spavanja p=0,034, manje REM spavanja p= 0,034 (na račun više površnog NREM2 spavanja, ali ne statistički značajno, p=0,069) i da provode više vremena budni nakon započimanja spavanja (p=0,0002). Djeca s Downovim sindromom imaju značajno više opstruktivnih apneja i hipopneja po satu spavanja (viši OAHI) p=0,008, ali imaju manje centralnih apneja po satu spavanja (niži CAI) p=0,041, što pridonosi statistički neznačajno nižem ukupnom AHI-u (p=0,762) u djece s Downovim sindromom. Prosječno i najdulje trajanje apneja nije se značajno razlikovalo između dviju skupina. Djeca s Downovim sindromom su imala značajno niže i prosječne i nadir saturacije kisika (p=0,008 i p=0,001). Zaključak: Možemo prevenirati većinu respiratornih komplikacija u djece s Downovim sindromom podizanjem svjesnosti njihovih roditelja o poremećajima spavanja u te djece, ali i zdravstvenih djelatnika, te uključivanjem rutinske cjelonoćne videopolisomnografije u njihovo praćenje.

Background: The need to satisfy high-throughput demands for laboratory tests continues to be a challenge. Therefore, we aimed to automate postanalytical phase in hematology and coagulation laboratory by autovalidation of complete blood count (CBC) and routine coagulation test results (prothrombin time [PT], international normalized ratio [PT-INR], activated partial thromboplastin time [APTT], fibrinogen, antithrombin activity [AT] and thrombin time [TT]). Work efficacy and turnaround time (TAT) before and after implementation of automated solutions will be compared. Methods: Ordering panels tailored to specific patient populations were implemented. Rerun and reflex testing rules were set in the respective analyzers’ software (Coulter DxH Connectivity 1601, Beckman Coulter, FL, USA; AutoAssistant, Siemens Healthcare Diagnostics, Germany), and sample status information was transferred into the laboratory information system. To evaluate if the automation improved TAT and efficacy, data from manually verified results in September and October of 2015 were compared with the corresponding period in 2016 when autovalidation was implemented. Results: Autovalidation rates of 63% for CBC and 65% for routine coagulation test results were achieved. At the TAT of 120 min, the percentage of reported results increased substantially for all analyzed tests, being above 90% for CBC, PT, PT-INR and fibrinogen and 89% for APTT. This output was achieved with three laboratory technicians less compared with the period when the postanalytical phase was not automated. Conclusions: Automation allowed optimized laboratory workflow for specific patient populations, thereby ensuring standardized results reporting. Autovalidation of test results proved to be an efficient tool for improvement of laboratory work efficacy and TAT.

Summary Diagnosis of haemophilia A is usually made by the measurement of factor VIII (FVIII) activity that allows categorization of the disease severity. However, tests that assess global haemostasis may better reflect clinical features and give additional clinically relevant information. The aim of this study was to develop a new quantitative activated partial thromboplastin time (aPTT) waveform analysis and compare it with FVIII activities to find out whether waveform parameters are superior determinants of clinical phenotype. A total of 81 haemophilia A patients divided into two groups (37 severe, 44 non-severe) were included in the study. The control group comprised 101 healthy male volunteers. Quantitative aPTT waveform analysis was performed with Actin FS on BCS (Siemens Healthcare Diagnostics, Marburg, Germany) using three parameters (DELTA, RATIO-1, RATIO-2) obtained from a single aPTT measurement with two evaluation modes. FVIII activities were measured by one-stage clotting and two-stage chromogenic assay. Statistically significant difference (P

Modern photo-optical coagulometers collect optical data in the form of reaction curves and offer a possibility to determine clotting times at different points of clot formation by using different evaluation modes. The objectives of this study were to determine the possible impact of an evaluation mode on activated partial thromboplastin time (APTT) results and to investigate potential benefits from visual inspection of obtained reaction curves. APTT was determined by using actin FS as reagent on two coagulometers (Siemens Medical Solutions) in 174 plasma samples with three different evaluation modes: fixed absorbance(FA), drifting baseline (DB), and point of inflexion (POI) on Behring coagulation timer (BCT), and with DB mode on Behring coagulation system (BCS). Statistically significant difference of APTT results applying the Friedman’s test (P < 0.0001) followed by Dunn’s multiple comparison test (P < 0.05) was obtained in all tested samples between POI mode and all other evaluation modes, independently of analyzer used. The differences obtained indicated that laboratory professionals must be aware of possible different evaluation modes on different analyzers, and establish evaluation mode-specific reference intervals. Moreover, correctness of a reported result could be confirmed only by visual analysis of the reaction curve.

Background: Widespread use of D-dimer in recent years has led to the development of a number of new fully automated quantitative D-dimer assays. Methods: We evaluated the analytical performance of the particle-enhanced immunoturbidimetric assay Innovance D-DIMER (Siemens Medical Solutions) on the Behring Coagulation System (BCS) analyzer. Results: Within-run coefficients of variation (CVs) for samples with low, borderline, slightly, and extremely increased D-dimer concentrations were 2.1%–5.5%, whereas between-run CVs for control samples with low and extremely increased D-dimer were 5.5%–8.4%. The assay exhibited good linearity in the working range between 0.17 mg/L and 5.45 mg/L fibrinogen equivalent units (FEU), with the lower limit of detection of 0.099 mg/L FEU. The upper reference value determined in 40 plasma samples from healthy volunteers was 0.495 mg/L FEU. The results obtained in 457 fresh plasma samples were compared with results obtained with VIDAS D-Dimer Exclusion. Passing and Bablok regression analysis demonstrated highly significant correlation (y=1.370x–0.108, r=0.952, p

Uvod: Laboratorijsko razlikovanje glomerularne i neglomerularne hema-turije godinama se uglavnom temelji na ispitivanju morfologije eritrocita u mokraći. Za razliku od eritrocita iz donjih mokraćnih puteva koji su intaktni, pravilnih oblika, glomerularni eritrociti su manji i imaju nepravilne i složene oblike. U ovom raduje ispitana mogućnost razlikovanja podrijetla hematurije protočnom citometrijom, mjerenjem parametara ovisnih o morfološkim značajkama eritrocita u mokraći nakon obilježavanja eritrocita fluorescentnim monoklonskim antitijelima na glikoforin A. Materijali i metode: Svježi uzorci mokraće od ukupno 31 bolesnika s dokazanim glomerularnim i 31 bolesnika s dokazanim urološkim bolestima analizirani su na protočnom citometru FACScan (Becton Dickinson, San Jose, SAD). Eritrociti su izdvojeni od ostalih stanica i nestaničnih elemenata u mokraći bojenjem fluorescentnim monoklonskim antitijelima na glikoforin A, a zatim su mjereni intenziteti rasapa svjetlosti u smjeru ulazne zrake (engl. forward scatter, FSC) i okomito na smjer ulazne zrake (engl. sidescatter, SSC), te je izračunat omjer SSC/FSC. FSC je bio mjera veličine, a SSC mjera oblika eritrocita. Rezultati: Nađena je statistički značajna razlika u izmjerenim vrijednostima FSC (P < 0,001), SSC (P = 0,016), kao i u omjeru SSC/FSC (P < 0,001) između dviju skupina bolesnika. Prema ROC analizi (engl. ReceiverOperating Characteristic) dobiveni su slijedeći rezultati: za FSC (granična vrijednost za glomerular-nu hematuriju FSC ≤ 49) dijagnostička osjetljivost 90,3% i specifičnost 83,9%; za SSC (granična vrijednost za glomerularnu hematuriju SSC > 73) dijagnostička osjetljivost 83,9% i specifičnost 61,3%; za omjer SSC/FSC (granična vrijednost za glomerularnu hematuriju SSC/FSC > 2,42) dijagnostička osjetljivost 83,9% i specifičnost 90,3%. Zaključak: Opisana metoda analize eritrocita protočnom citometrijom je jednostavna, automatizirana tehnika za razlikovanja podrijetla hematurije. U odnosu na metodu ispitivanja morfologije eritrocita daje objektivnije i pouzdanije podatke, te omogućuje usmjeravanje bolesnika prema urološkoj, odnosno nefrološkoj problematici., Background: Glomerular and urinary tract origins of hematuria are differentiated on the basis of urinary red cell morphology. Glomerular erythro-cytes are distorted and are smaller than erythrocytes from the lower urinary tract. In this study, we investigated the possibility of flow cytometric differentiation of the origin of hematuria using phycoerythrin-conjugated antibody against glycophorin A, by measuring parameters dependent on morphologic characteristics of urinary erythrocytes. Materials and methods: Fresh urine samples from 31 patients with glomerular disease and 31 patients with urological disease were analyzed on the flow cytometer FACScan (Becton Dickinson, San Jose, USA). Erythrocytes were distinguished from other particles with similar size in urine by staining with phycoerythrin-conjugated antibody against glycophorin A. The intensity of forward scattered light (FSC) and side scattered light (SSC) of the erythrocytes were measured as indicators of red cell size and shape, respectively. Also, the SSC/FSC ratio was calculated. Results: A statistically significant difference in FSC (P < 0.001), SSC (P = 0.016) and SSC/FSC ratio (P < 0.001) values between two groups of patients were found. According to ROC analysis (Receiver Operating Characteristic) the following results were obtained in distinguishing the origin of hematuria: for FSC (cut-off value for glomerular hematuria: FSC ≤ 49), diagnostic sensitivity 90.3% and specificity 83.9%; for SSC (cut-off value for glomerular hematuria: SSC > 73), diagnostic sensitivity 83.9% and specificity 61.3%; for SSC/FSC ratio (cut-off value for glomerular hematuria: SSC/FSC > 2.42), diagnostic sensitivity 83.9% and specificity 90.3%. Conclusion: The described flow cytometry analysis is a simple, automated method that can be used to establish distinction between glomerular and non-glomerular bleeding. Compared to the method of urinary red cell morphology examination, it yields more objective and reliable informations and allows directing of patients to urologic or nephrologic treatment.

The authors evaluated the reliability of prothrombin time (PT) and activated partial thromboplastin time (aPTT) determination on a bedside coagulation monitor (CoaguChek Pro DM ; Roche Diagnostics, Germany). Measurement of PT and aPTT was performed in 54 specimens and was compared with reference laboratory methods. The obtained values for PT and aPTT in healthy subjects on CoaguChek were close to the reference interval established by the manufacturer, as well as the laboratory reference interval. Despite the good correlation coefficients for PT (r = 0.958) and aPTT (r = 0.885), there was an important dispersion of values between 2 methods as shown by Bland and Altman plots. In the group of 19 patients on oral anticoagulant therapy, comparable values were observed in 14 cases, whereas discrepancy between 5 results could lead to a different therapeutic decision. CoaguChek aPTT determination was shown to be a good method for monitoring unfractionated heparin therapy. However, the results should not be compared with each other, and the same technique should always be chosen to monitor patients.