OBJECTIVES:The aim of the study was to assess requesting patterns of procalcitonin in adult patients presenting at the Emergency Department (ED), evaluate usefulness of the obtained result on clinical decision-making process in terms of antibiotic prescriptions and determine its diagnostic accuracy for sepsis diagnosis. METHODS:Categories of patients in whom procalcitonin was requested were based on clinical, imaging and laboratory data, and were classified as follows: uncertain cause of fever in patients without major comorbidities, with cancer, in immunosupressed patients, evaluation of disease severity when infection is evident and unclear reason for testing. Usefulness of procalcitonin determination was evaluated by two senior physicians according to all available clinical data. Impact of procalcitonin results on decision-making process was assessed by analysis of antibiotic prescriptions. Diagnostic sensitivity and specificity of procalcitonin for sepsis diagnosis were determined at the cut-off of 2.0 μg/L. RESULTS:Procalcitonin is mostly ordered due to unexplained fever, but in one third of patients is ordered with evident infection or for unclear reason. Procalcitonin was considered useful in 25 % of patients, regardless of the reason for determination (p=0.688). Patients were equally likely to receive antibiotic treatment, regardless of procalcitonin concentrations (p=0.846). Procalcitonin revealed 35 % sensitivity and 84 % specificity for sepsis diagnosis. CONCLUSIONS:Despite frequent ordering of procalcitonin in patients with fever at the ED, the obtained result is not a decisive factor for further patient management. Procalcitonin alone has limited ability in distinguishing infectious from non-infectious causes of fever in patients presenting at the ED.

Background/Objectives: To establish reference intervals (RIs) and cut-off values for thyroid-related tests on the MAGLUMI X6 immunoassay analyzer (Snibe Diagnostic, Shenzhen, China) in an adult Croatian population. Methods: This study included 305 healthy individuals who underwent regular preventive medical checkup. The following tests were determined in serum: thyroid-stimulating hormone (TSH), total triiodothyronine (TT3), total thyroxine (TT4), free triiodothyronine (FT3), free thyroxine (FT4), thyroglobulin (Tg), reverse triiodothyronine (revT3), total binding capacity of thyroglobulin (T-uptake), thyroglobulin antibodies (anti-Tg), anti-thyroid peroxidase antibodies (anti-TPO) and thyroid receptor antibodies (TRAb). TSH, TT3, TT4, FT3, FT4, Tg, revT3 and T-uptake results were used for calculating double-sided 95% RIs between the 2.5th and 97.5th percentiles. For anti-Tg, anti-TPO and TRAb, right-sided cut-offs that correspond to the 95th percentile were determined. Results: Reference intervals for TSH, TT4, FT3, FT4, Tg, T-uptake and revT3 did not differ by gender (p > 0.05) and were 0.77–5.04 mIU/L, 69.9–127.7 nmol/L, 3.84–6.20 pmol/L, 13.8–19.7 pmol/L, 1.8–51.2 µg/L, 0.9–1.2 TBI and 0.44–0.73 ng/mL, respectively. The RI for TT3 was different for males (1.49–2.53 nmol/L) and females (1.43–2.81 nmol/L), p = 0.021. A single cut-off for anti-TPO was established (<18 kIU/L). Differences in cut-offs for males and females were obtained for anti-Tg (<72 and <104 kIU/L, respectively) and TRAb (0.6 and 0.9 IU/L, respectively). Conclusions: This is the first study to determine RIs for thyroid function tests in Croatian adults on the Snibe analytical platform. The obtained results point out to the use of population- and immunoassay-specific RIs. For TT3, anti-Tg and TRAb gender-specific RIs should be considered.

Aims: With an ever-growing number of patients being admitted to our University Hospital Sveti Duh (Zagreb, Croatia), there was a need to positively respond to clinicians' demands about hereditary and acquired thrombophilia testing. Study Design: An extensive and multicentric verification of coagulation assays included in thrombophilia testing was performed on the BCS XP coagulation analyzer (Siemens Healthineers, Marburg, Germany): antithrombin activity (AT) (Innovance Antithrombin), protein C activity (PC) (Berichrom Protein C), protein S activity (PS) (Protein S Ac), free protein S antigen (free PS:Ag) (Innovance Free PS Ag), activated protein C resistance (APCR) (ProC Ac R and ProC Global + Coagulation Factor V Deficient Plasma), lupus anticoagulant (LA) screening (LA1 and activated partial thromboplastin time by using Dade Actin FSL as reagent) and confirmation test (LA2), factor VIII activity (FVIII) (Dade Actin FS and coagulation FVIII Deficient Plasma). Place and Duration of Study: Department of Medical Laboratory Diagnostics, University Hospital Sveti Duh, Zagreb, Croatia, between January 2020 and December 2021. Methodology: Verification protocol included: the precision study (CLSI EP15-A3 protocol), trueness estimation by comparison of seventy remnant plasma samples with two large Croatian hospital laboratories with established thrombophilia testing, and verification of reference intervals and cut-off values (CLSI EP28-A3C and CLSI HA-60 guidelines). Results: All of the obtained imprecision CVs were within the manufacturer's claims (<5/10/15%). While the observed bias for PC (+1.9%) was within the EFLM performance specifications (6.7%), the average bias for AT was higher than acceptance criteria (+10.8% vs 3.2% allowed). P&B regression revealed a significant positive proportional difference (slope=1.14). Comparison of PS activity yielded a high negative bias (-33.4%) that exceeded the acceptance criteria of 8.1%. Regarding LA testing, the diagnostic accuracy was 99% when compared to Sestre milosrdnice UHC (N=70) and 95% when compared to University Hospital Centre Zagreb (N=19). All manufacturer's reference intervals and cut-offs were verified. Conclusion: The verification study confirmed all manufacturer's claims, except for PS which has been replaced with free PS:Ag determinations.

Introduction:The aim of this study was to investigate attitudes and routine procedures in point of care testing (POCT) among non-laboratory and laboratory healthcare professionals in Croatia. Materials and methods:The Working Group (WG) for POCT of the Croatian society of medical biochemistry and laboratory medicine has designed two anonymous surveys for laboratory staff and non-laboratory staff with a total of 44 questions/statements on POCT (27 questions for non-laboratory staff and 17 for laboratory staff). Surveys were sent to 184 medical biochemistry laboratory (MBL) managers, the Croatian medical chamber and the Croatian chamber of nurses. The survey was disseminated using the online survey platform SurveyMonkey. Results:A total of 112 non-laboratory healthcare professionals and 50 laboratories participated in the survey, which represents a response rate of 0.25% for non-laboratory professionals and 27% for MBLs. The majority of non-laboratory staff stated that POCT enables better medical care for the patient (90/112) and that the implementation of new POCT devices should be the responsibility of a POCT team comprising laboratory and clinical healthcare professionals. The great majority of responding MBLs (42/50) acknowledge that POCT is necessary for better patient care, and also realize that validation of POCT devices and comparison to the central laboratory is necessary before implementation (49/50). Conclusions:The majority of participants consider POCT as a medical tool that enables better patient care but there is still a lack of communication between laboratory and clinical staff. The study identified some critical spots that will help to create national guidelines to ensure high patient safety when using POCT devices.

This study aimed to assess analytical characteristics and diagnostic accuracy in management of venous thromboembolism (VTE) in the Emergency Department (ED) of the Abbott D-dimer assay applied on the Alinity c clinical chemistry analyzer (Abbott Laboratories, Chicago, IL) compared to the INNOVANCE D-dimer assay (Siemens Healthineers, Marburg, Germany). Precision was determined at three concentration levels following the CLSI EP15-A3 protocol. Method comparison and diagnostic accuracy were assessed using samples obtained from 85 patients who were referred for diagnostic imaging and D-dimer testing due to clinically suspected VTE. Within-run coefficients of variation (CVs) were 3.0%, 0.5% and 0.5% at D-dimer concentrations of 0.54, 1.42 and 2.68 mg/L FEU, while respective between-run CVs were 2.0%, 3.4% and 2.7%, hence fulfilling the desirable biological variation criteria for imprecision (<12.6%). Passing-Bablok regression analysis yielded a small proportional difference between the two compared assays (y = 1.09 (95% confidence interval (CI): 1.01-1.18) x + 0.09 (95%CI: -0.09 to 0.16)), while Bland-Altman analysis showed significant negative absolute (-0.6 mg/L FEU, 95%CI: -0.9 to -0.3) and relative mean bias (-14.1%, 95%CI: -20.3 to -7.9). Spearman's rho was 0.979 (95%CI: 0.967-0.986). Inter-assay agreement relative to the cut-off was 92% (kappa coefficient = 0.547 (95%CI: 0.255-0.839)). Diagnostic sensitivity, specificity, positive and negative predictive values of the Abbott assay were 100%, 9.2%, 25.3% and 100%, respectively, compared to the following data for the INNOVANCE assay: 95.0%, 15.4%, 25.7% and 90.9%. Abbott D-dimer assay has shown excellent analytical precision, high comparability with the INNOVANCE D-dimer and high NPV at manufacturer's cut-off.

Introduction: Due to high inter-observer variability the 2015 International Council for Standardization in Haematology (ICSH) recommendations state to count band neutrophils as segmented neutrophils in the white blood cell (WBC) differential. However, the inclusion of bands as a separate cell entity within the WBC differential is still widely used in hematology laboratories in Croatia. The aim of this multicentric study was to assess the degree of inter-observer variability in enumerating band neutrophils within the WBC differential among Croatian laboratories. Materials and methods: Seven large Croatian hospital laboratories from different parts of the country participated in the study. In each of 7 participating laboratories, one blood smear, that was flagged by the analyzer as possibly having bands, was evaluated by all personnel participating in the analysis of hematology samples. Between-observer manual smear reproducibility was expressed as coefficient of variation (CV) and calculated Results: The CVs (%) and relative band neutrophil counts in participating laboratories were as follows: 15.4% (16-24), 19.2% (16-32), 19.5% (17-40), 21.1% (17-44), 35.0% (8-26), 51.9% (3-29), and remarkably high 62.4% (12-59). For segmented neutrophils CVs were lower, ranging from 7.4% to 32.2%. The CVs did not correlate with the number of staff members in each hospital (P = 0.293). Conclusions: This study revealed very high variability in enumerating band neutrophil count in the blood smear differential among all participants, thus prompting a need for action on a national level.

BACKGROUND:Diagnostic accuracy of glial fibrillary acidic protein (GFAP) and ubiquitin C-terminal hydrolase L1 (UCH-L1) in identification of intracranial abnormalities detected by computed tomography (CT) in mild traumatic brain injury (mTBI), and in patients with mild neurological symptoms not caused by head trauma but suspected with a neurological disorder, was examined. METHODS:GFAP and UCH-L1 were determined using the chemiluminescence immunoassays on the Alinity i analyzer (Abbott Laboratories). RESULTS:Significantly higher GFAP (median 53.8 vs 25.7 ng/L, P < .001) and UCH-L1 (median 350.9 vs 153.9 ng/L, P < .001) were found in mTBI compared to non-head trauma patients. In mTBI diagnostic sensitivity (Se) and specificity (Sp) for the combination of GFAP and UCH-L1 were 100% and 30.9%, respectively, with area under the curve (AUC) 0.655. GFAP alone yielded Se 85.7%, Sp 41.8%, and AUC 0.638, while UCH-L1 yielded Se 57.1%, Sp 56.4%, and AUC 0.568. In non-head trauma patients, the combination of GFAP and UCH-L1 showed Se 100%, Sp 87.9%, and AUC 0.939, while GFAP alone demonstrated Se 100%, Sp 90.9%, and AUC 0.955. CONCLUSIONS:If these results are reproduced on a larger sample, GFAP and UCH-L1 may reduce CT use in patients with mild neurological symptoms after systemic causes exclusion and neurologist's evaluation.

Although we did not face the coagulation tube shortage due to increased testing for assessing coagulopathy associated with severe COVID-19 illness, with great interest, we have read the article by Gosselin et al. [1Gosselin R.C. Bowyer A. Favaloro E.J. Johnsen J.M. Lippi G. Marlar R.A. Neeves K. Rollins-Raval M.A. Guidance on the critical shortage of sodium citrate coagulation tubes for hemostasis testing.J Thromb Haemost. 2021; 19: 2857-2861Abstract Full Text Full Text PDF PubMed Scopus (8) Google Scholar], not knowing that we would have to employ their recommendations sooner than expected. In May 2022, Becton, Dickinson, and Company issued a product discontinuation notification regarding BD Vacutainer citrate glass blood collection tubes, including 3.2% and 3.8% buffered sodium 4.5-mL and 6.0-mL tubes. Suggested alternative products were 2.7 mL plastic 3.2% and 3.8% buffered sodium citrate blood collection tubes [2BD IDS–specimen management. Product discontinuation notification BD Vacutainer® Citrate Glass Blood Collection Tubes. DocuSign Envelope ID: F14C6815-220D-467A-8161-F91414B5E744.Google Scholar]. The discontinuation was announced for September 1, 2022. Since we performed a multicentric verification of hereditary and acquired thrombophilia coagulation assays (data not published) during 2021, prior to its implementation into everyday routine, by exclusively using BD Vacutainer 9NC 0.105 M 3.2% buffered sodium citrate blood collection 4.5-mL glass tubes, we were obliged to evaluate and validate the proposed tube replacement, as suggested by Gosselin et al. [1Gosselin R.C. Bowyer A. Favaloro E.J. Johnsen J.M. Lippi G. Marlar R.A. Neeves K. Rollins-Raval M.A. Guidance on the critical shortage of sodium citrate coagulation tubes for hemostasis testing.J Thromb Haemost. 2021; 19: 2857-2861Abstract Full Text Full Text PDF PubMed Scopus (8) Google Scholar]. Because of the nature and the costs of hereditary and acquired thrombophilia testing, we had to downsize the suggested number of samples (40) for tube comparison [1Gosselin R.C. Bowyer A. Favaloro E.J. Johnsen J.M. Lippi G. Marlar R.A. Neeves K. Rollins-Raval M.A. Guidance on the critical shortage of sodium citrate coagulation tubes for hemostasis testing.J Thromb Haemost. 2021; 19: 2857-2861Abstract Full Text Full Text PDF PubMed Scopus (8) Google Scholar]. During the last quarter of 2023, we have collected 20 paired samples from patients who had both hereditary and acquired thrombophilia screening tests ordered. As the standard laboratory protocol for thrombophilia testing comprises collection of 2 coagulation tubes, patients were not asked for informed consent. Instead, 1 glass tube was replaced with a plastic tube, preserving the total venipuncture volume. Samples were drawn into both BD Vacutainer 9NC 0.105 M 3.2% buffered sodium citrate glass 4.5-mL blood collection tubes (REF 367714, lot 2200088, expiry January 2024) and BD Vacutainer 9NC 0.109 M 3.2% buffered sodium citrate plastic 2.7-mL blood collection tubes (REF 3178564, lot 3058244, expiry March 2024). The collected 20 samples were tested for the following hereditary and acquired thrombophilia coagulation assays: antithrombin activity, protein C activity, free protein S antigen, factor VIII activity, and lupus anticoagulant. The listed assays comprised clot-based assays, immunoassays, as well as chromogenic assays, as recommended by Gosselin et al. [1Gosselin R.C. Bowyer A. Favaloro E.J. Johnsen J.M. Lippi G. Marlar R.A. Neeves K. Rollins-Raval M.A. Guidance on the critical shortage of sodium citrate coagulation tubes for hemostasis testing.J Thromb Haemost. 2021; 19: 2857-2861Abstract Full Text Full Text PDF PubMed Scopus (8) Google Scholar]. All reagents were manufactured by Siemens (Siemens Healthcare Diagnostics Products GmbH), as listed in the Table. The obtained samples were double-centrifuged at 1500g for 15 minutes to ensure that the residual platelet count in the plasma was <10 × 109/L. Plasma was aliquoted and frozen at −80 °C until analysis. All samples were tested on the BCS XP analyzer (Siemens Healthineers) within 2 weeks from phlebotomy. Frozen plasma aliquots were thawed in a water bath at 37 °C, well stirred, and assayed as a batch. As 20 patients are considered to be a statistically small sample, the nonparametric Wilcoxon test for paired samples was used for statistical analysis. Additionally, an average bias was calculated between the samples obtained from different tubes by employing the Bland-Altman plot. Average bias was expressed as percentage and compared to the minimum allowed bias according to the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) Biological Variation Database [3Aarsand A.K. Fernandez-Calle P. Webster C. Coskun A. Gonzales-Lao E. Diaz-Garzon J. et al.The EFLM biological variation database.https://biologicalvariation.eu/Date accessed: November 6, 2023Google Scholar]. Statistical analysis was performed in MedCalc statistical software version 22.014 (MedCalc Software Ltd).TableComparison of glass and plastic BD 3.2% citrate coagulation tubes for hereditary and acquired thrombophilia testing on a Siemens BCS XP analyzer.N = 20Wilcoxon test for paired samplesBland-Altman plotTestReagentRangeGlassaMeasurements are given as median (IQR).PlasticaMeasurements are given as median (IQR).P valuebA P value of <.05 is considered significant.Bias (95% CI)P valuebA P value of <.05 is considered significant.EFLM criteriacMinimum criteria for bias, European Federation of Clinical Chemistry and Laboratory Medicine biological variation database.Antithrombin activity (%)INNOVANCE Antithrombin77.8 to 111.195.7 (88.1 to 105.1)94.5 (85.8 to 103.2).0082.3 (0.6 to 3.9).0103.2Protein C activity (%)Berichrom Protein C46.3 to 143.7100.7 (89.6 to 121.0)102.8 (89.1 to 124.7).254−1.2 (−2.9 to 0.6).1996.7Free protein S antigen (%)INNOVANCE Free PS Ag53.5 to 143.984.3 (72.1 to 100.4)86.1 (74.4 to 100.5).390−0.9 (−3.1 to 1.2).3546.5Factor VIII (%)Dade Actin FS and Coagulation Factor VIII-Deficient Plasma120.5 to 324.8171.4 (146.5 to 227.1)175.9 (147.6 to 223.7).8720.2 (−3.6 to 4.0).9359.0DRVVT lupus anticoagulant screening (s)LA1 screening reagent30.5 to 75.136.6 (33.6 to 43.0)37.2 (35.0 to 45.7).150−1.8 (−3.7 to 0.2).074NAAPTT lupus anticoagulant screening (s)Dade Actin FSL activated PTT reagent24.4 to 39.527.7 (25.5 to 29.6)27.4 (26.4 to 29.5).455−1.0 (−3.3 to 1.4).413NAAPTT, activated partial thromboplastin time; DRVVT, dilute Russell viper venom time; EFLM, European Federation of Clinical Chemistry and Laboratory Medicine; NA, not available; PTT, partial thromboplastin time.a Measurements are given as median (IQR).b A P value of <.05 is considered significant.c Minimum criteria for bias, European Federation of Clinical Chemistry and Laboratory Medicine biological variation database. Open table in a new tab APTT, activated partial thromboplastin time; DRVVT, dilute Russell viper venom time; EFLM, European Federation of Clinical Chemistry and Laboratory Medicine; NA, not available; PTT, partial thromboplastin time. There was no statistically significant difference in paired measurements for all assays, except for antithrombin activity (P = .008). The Bland-Altman plot confirmed statistically significant bias for antithrombin activity (2.3%; 95% CI, 0.6%-3.9%; P = .010). However, the observed bias was within the allowed EFLM Biological Variation Database criteria (3.2%) and, thus, clinically insignificant. To the best of our knowledge, only 1 paper addressed this issue by using Siemens coagulation reagents for thrombophilia testing [4Gosselin R.C. Janatpour K. Larkin E.C. Lee Y.P. Owings J.T. Comparison of samples obtained from 3.2% sodium citrate glass and two 3.2% sodium citrate plastic blood collection tubes used in coagulation testing.Am J Clin Pathol. 2004; 122: 843-848Crossref PubMed Scopus (29) Google Scholar]. Similar to our findings, Gosselin et al. [4Gosselin R.C. Janatpour K. Larkin E.C. Lee Y.P. Owings J.T. Comparison of samples obtained from 3.2% sodium citrate glass and two 3.2% sodium citrate plastic blood collection tubes used in coagulation testing.Am J Clin Pathol. 2004; 122: 843-848Crossref PubMed Scopus (29) Google Scholar] found a statistically significant difference in antithrombin activity between glass and plastic collection tubes/vacutainers, with antithrombin being lower in the plastic tube. However, as the authors hypothesized that the possible cause would be thrombin as a component in the antithrombin reagent since the method was chromogenic with thrombin substrate, this could not be applied in our case. The reagent used in the present study, Siemens INNOVANCE Antithrombin, utilizes a chromogenic measuring principle where an excess of FXa is added to citrated plasma. It remains unclear why the antithrombin test would be affected by plastic blood collection methods. On the contrary, Kratz et al. [5Kratz A. Stanganelli N. Van Cott E.M. A comparison of glass and plastic blood collection tubes for routine and specialized coagulation assays: a comprehensive study.Arch Pathol Lab Med. 2006; 130: 39-44Crossref PubMed Google Scholar] did not find a statistical difference in antithrombin activity between glass and plastic coagulation tubes. However, although they employed the same method principle (thrombin-based chromogenic) as that used by Gosselin et al. [4Gosselin R.C. Janatpour K. Larkin E.C. Lee Y.P. Owings J.T. Comparison of samples obtained from 3.2% sodium citrate glass and two 3.2% sodium citrate plastic blood collection tubes used in coagulation testing.Am J Clin Pathol. 2004; 122: 843-848Crossref PubMed Scopus (29) Google Scholar], their reagents were manufactured by Diagnostica Stago, and samples were measured on a different analytical platform (Diagnostica Stago STA-R). As stated in the current recommendations by the Scientific and Standardization Committee of the International Society on Thrombosis and Haemostasis [6Van Cott E.M. Orlando C. Moore G.W. Cooper P.C. Meijer P. Marlar R. Subcommittee on Plasma Coagulation Inhibitors. Recommendations for clinical laboratory testing for antithrombin deficiency; Communication from the SSC of the ISTH.J Thromb Haemost. 2020; 18: 17-22Abstract Full Text Full Text PDF PubMed Scopus (54) Google Scholar], several conditions, such as type of assay and incubation time, can influence sensitivity and specificity of the activity assays, thus supporting the need for similar studies that should be performed on equal platforms and be reagent-dependent. Regarding dilute Russell viper venom time lupus anticoagulant screening, which Gosselin et al. [4Gosselin R.C. Janatpour K. Larkin E.C. Lee Y.P. Owings J.T. Comparison of samples obtained from 3.2% sodium citrate glass and two 3.2% sodium citrate plastic blood collection tubes used in coagulation testing.Am J Clin Pathol. 2004; 122: 843-848Crossref PubMed Scopus (29) Google Scholar] found statistically different between collection methods, we observed no statistically significant difference between glass and plastic collection tubes. Additionally, our study is the first study that compared glass and plastic plasma samples for free protein S antigen measurement. The difference was insignificant. However, our study has some limitations. We did not compare activated protein C resistance ratio due to lack of patients with that request. Additionally, only 4 patients had prolonged lupus anticoagulant screening, thus needing the confirmation assay, and therefore, due to a very small sample, statistical analysis was inappropriate. In conclusion, the replacement of glass BD 3.2% sodium citrate tubes with plastic BD 3.2% sodium citrate tubes does not significantly affect testing results, and thus, plastic tubes are acceptable for hereditary and acquired coagulation thrombophilia testing on a Siemens BCS XP analyzer using reagents manufactured by Siemens. There are no competing interests to disclose. Each author contributed to the writing, reviewing, revision, and acceptance of the manuscript.

OBJECTIVES:It has been recognized that shortened activated partial thromboplastin time (aPTT) may be caused by various preanalytical conditions. As coagulation Factor VIII is included in the in vitro intrinsic coagulation cascade measured by aPTT, we hypothesized that the shortened aPTT could be a result of elevated FVIII activity. We aimed to inspect the connection of elevated FVIII with shortened aPTT, and the possible effect inflammation has on routine laboratory parameters. METHODS:40 patients from various hospital departments with aPTT measurement below the lower limit of the reference interval (<23.0 s) were included in the study. To compare the obtained results with aPTT measurements in the non-inflammatory state, samples from 25 volunteers (laboratory personnel) were collected. White blood cell count, C-reactive protein, aPTT, and FVIII values were measured in the control group. RESULTS:Only two samples among 40 patients with shortened aPTT (5 %) were clotted. Out of the remaining 38, 26 had FVIII activity above 150 % (upper limit of a reference interval), median value of 194 % (IQR: 143-243 %). Seven samples in the control group had shortened aPTT results (36 %). However, all coagulation samples were clot and hemolysis-free. Multiple regression identified only FVIII activity as an independent variable in predicting aPTT values (p=0.001). CONCLUSIONS:Our results support the thesis that shortened aPTT is rarely a consequence of preanalytical problems. Elevated FVIII activity causes shortened aPTT, not only in the inflammatory state but also in individuals with concentration of inflammatory markers within reference intervals.

Pseudothrombocytopenia (PTCP) is defined by the occurence of spouriously low platelet count as a consequence of in vitro platelet aggregation. It is a rare and benign artifact, not associated with any specific disorder or therapy, that becomes clinically relevant when it is not timely and reliably recognized. Thus, it may result in inappropriate clinical decisions (i.e. unnecessary further testing, misdiagnoses and potential patients' mismanagement) unavoidably compromising patient safety. The most common form of PTCP is caused by ethylenediaminetetraacetic acid (EDTA). Several approaches for the management of samples with EDTA-induced PTCP have been described in the literature. However, expert recommendations are scarce. The scope of these recommendations is to assist in achieving national harmonisation in laboratory management (i.e. detecting and reporting platelet counts) of samples with EDTA-induced PTCP. These minimal recommendations were prepared by the members of the joint working group of the Croatian Chamber of Medical Biochemists and Working group for Laboratory Hematology of the Croatian Society of Medical Biochemistry and Laboratory Medicine, and might be customized according to specific conditions (i.e. personnel and equipment) of each individual laboratory. These recommendations are primarily intended to all laboratory professionals involved in the management of samples with EDTA-induced PTCP, but also to other healthcare professionals involved in collecting samples and interpreting complete blood count results.

Although clear and detailed recommendation regarding the lupus anticoagulant mixing test exist, various sources of NPP are used. We decided to inspect the possible differences in mixing studies depending on the mixing media. Four types of mixing media were prepared for 45 random remnant plasma samples: standard human plasma, control plasma N, previously analyzed patient with normal coagulation values, and home-made normal pool plasma (NPP). Samples were analyzed by using Siemens Dade Actin FSL Activated PTT Reagent on BCS XP analyzer. The median aPTT values of mixing studies with commercial lyophilized NPP, with commercial IQC, as well as with a patient did not differ (26.6, 26.3, and 26.8 s, respectively). Median value of a mixing study with home-made NPP was significantly higher from the rest of the group (27.9 s) ( P < 0.05). According to the obtained results, we decided to employ the commercial lyophilized NPP for future lupus anticoagulant mixing studies.

OBJECTIVES:The aim of the present study was to assess the effect of repeated laboratory measurement of C-reactive protein (CRP) and leukocyte count on the decision whether to admit or dicharge the patient with localized infections who received antibiotics at the Emergency Department (ED) observation unit. METHODS:Adult patients with respiratory, urinary tract and abdominal infections, observed at the ED after antibiotic administration, in whom repeated measurements of CRP and leukocyte count were performed within 24 h, were included. They were initially grouped as planned discharge, planned admission and unclear attitude towards admission. Initial and repeated CRP and leukocyte count results, clinical dynamics (improvement, worsening, unchanged) and clinical decision about discharge or admission, were recorded. RESULTS:A total of 1,038 patients were eligible for inclusion. No significant differences in initial CRP and leukocyte count values were observed, nor any association of CRP and leukocyte count changes with clinical dynamics. Among 504 patients eligible for discharge at second laboratory sampling according to clinical dynamics, 54.4 % were further observed or admitted. Discharged patients had an average negative absolute (p<0.001) and relative CRP change (p=0.002). Clinical dynamics, first and second CRP results and absolute CRP change were independently associated with the decision to discharge or further observe/admit. CONCLUSIONS:Schematic repetitions of CRP and leukocyte count at the ED observation unit are common, regardless of patients' clinical condition. Clinical judgment remains the main guiding factor to admit or discharge the patient, but repeated CRP testing influences the final decision, contributing to higher admission rates.

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).

Ion-selective electrode pocket meters available for use with saliva could be a convenient tool to assess how diseases, drugs, exercise or nutrition affect salivary composition. This study compared salivary sodium and potassium concentrations measured by handheld LAQUAtwin meters and a fully-automated biochemical analyzer. Agreement between two methods was assessed with Passing-Bablok regression and Bland-Altman plots. LAQUAtwin meters measured lower values of both analytes and provided repeatable though not accurate results. The meters may serve as an alternative to laboratory methods to gain insight into between-group differences in electrolyte concentrations, or a concentration change induced by an experimental procedure.

Abstract 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.