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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., Competing Interests: Potential conflict of interest None declared., (Croatian Society of Medical Biochemistry and Laboratory Medicine.)

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., (© 2024 Walter de Gruyter GmbH, Berlin/Boston.)

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., (© The Author(s) 2024. Published by Oxford University Press on behalf of American Society for Clinical Pathology. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

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 using the following formula: CV (%) = (standard deviation (SD)/mean value) x 100%., 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., Competing Interests: Potential conflict of interest None declared., (Copyright Croatian Society of Medical Biochemistry and Laboratory Medicine.)

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., (© 2024 Walter de Gruyter GmbH, Berlin/Boston.)

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., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

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., Competing Interests: Potential conflict of interest None declared., (Croatian Society of Medical Biochemistry and Laboratory Medicine.)

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 ρ 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: 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., (© 2023 John Wiley & Sons Ltd.)

Objectives: Guanylin peptides are considered to be the only intrinsic regulators of salivary glands secretion. Therefore, the aim of this study was to determine the effects of systemic uroguanylin (UGN) of the salivary flow and ion composition. Besides, the objective was to investigate whether those effects include activation of guanylate cyclase C (GC-C)., Material and Methods: This study was conducted on 7 months old C57Bl6NCrl (wild type, WT) and GC-C knockout (KO) mice. Salivary flow rate and ion composition were determined after pilocarpine stimulation with UGN (30 µg/animal) or saline i.p. application. The expression of mRNA for AQPs, NHEs, NBCn1, Slc26a3/a6 and CFTR were determined by qPCR in submandibular salivary glands., Results: When applied i.p., UGN decreased the pilocarpine stimulated saliva flow rate and increased the concentration of Na + , H + and Cl - . In GC-C KO mice, UGN showed no effect on saliva flow rate, while the concentrations of Na + , H + and Cl - are the same in GC-C KO littermates when compared to WT mice. UGN increased expression of Slc26a6 while in GC-C KO mice Slc26a6 had a higher expression when compared to WT mice, suggesting involvement of GC-C independent signalling pathway for UGN. The difference in Slc26a6 in GC-C KO mice is not unique for salivary glands because it was also found in duodenum and kidney cortex., Conclusions: The effects of UGN via basolateral membrane of salivary glands cells have not been considered up to date. In our study, UGN, when applied i.p., decreased salivary flow rate, pH, and changed the composition of other ions. Therefore, plasma UGN, an hour after a meal, could have physiological and pathological importance (development of cavities, inflammations or demineralizations), and the inhibition of systemic UGN effects could be considered a new approach in treatment of those conditions., Competing Interests: Conflict of interests: The authors report no conflict of interests., (University of Zagreb School of Dental Medicine.)

A 6-year-old boy was referred to a hematologist due to excessive mucocutaneous bleeding. Diagnostic assessment for von Willebrand disease (VWD) was indicated and included both coagulation and genetic testing. Laboratory testing revealed proportionally decreased von Willebrand factor (VWF) glycoprotein Ib-binding activity (23.6%) compared to VWF antigen (24.7%), similarly decreased VWF collagen-binding activity (24.2%), and normally distributed VWF multimers, with decreased intensity of all fractions. Diagnosis of type 1 VWD was established. Genetic analysis by means of next-generation sequencing (NGS) of VWF and coagulation factor VIII genes did not identify any causative mutations. Additionally, multiplex ligation-dependent probe amplification (MLPA) of VWF gene exons revealed a heterozygous deletion of exons 1 to 6, which is reported in type 1 VWD for the first time. Application of MLPA was crucial for revealing the genetic basis of type 1 VWD in this case, which would have remained undetected if only NGS was used., (© The Author(s) 2022. Published by Oxford University Press on behalf of American Society for Clinical Pathology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

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., (© 2023 Walter de Gruyter GmbH, Berlin/Boston.)

The aim of this cross-sectional study was to objectively assess the salivary flow rate and composition and periodontal inflammation in obstructive sleep apnoea (OSA) patients. The subjects, who underwent whole-night polysomnography or polygraphy, were referred for saliva sampling and periodontal examination. According to the severity of OSA based on the Apnoea Hypopnea Index (AHI) value, the subjects were classified into groups: no OSA (AHI < 5; N = 17), mild to moderate OSA (AHI 5-29.9; N = 109), and severe OSA (AHI > 30; N = 79). Salivary flow rate, pH, salivary electrolytes, and cortisol were measured from collected saliva samples. Periodontal examination included assessment of the number of teeth, dental plaque, bleeding on probing and periodontal measurements: gingival recession, probing pocket depth, clinical attachment level (CAL) and periodontal inflamed surface area (PISA) score. There were no significant differences in salivary flow rate, salivary pH, salivary electrolyte concentrations or electrolyte ratios among the groups classified according to the severity of OSA. However, subjects without OSA had higher salivary cortisol concentrations than OSA groups (p < 0.001). Increased plaque scores were associated with a higher AHI (r = 0.26; p = 0.003). According to the salivary flow rate, subjects with hyposalivation and reduced salivation had higher concentrations of salivary electrolytes and lower salivary pH than subjects with normal salivation. Subjects with hyposalivation had an increased Mg/PO 4 ratio (p < 0.001) and a reduced Ca/Mg ratio (p < 0.001). Furthermore, subjects with severe OSA tended to have higher CALs and plaque volumes. In conclusion, under pathological conditions, such as OSA, multiple interactions might impact salivary flow and electrolyte composition. Complex interrelationships might affect the integrity of oral health, especially considering OSA severity, inflammation, concomitant diseases and medications., (© 2022. The Author(s).)

This study aimed to determine antibody responses against SARS-CoV-2 spike (S) after both BioNTech-Pfizer Comirnaty vaccine doses and study the correlation with self-perceived adverse reactions. Antibodies determination with Elecsys anti-SARS-CoV-2 S assay was performed a day prior to or just before administration of the second dose and 8-13 days after the second dose. Participants selected from a predefined list of the experienced local (injection site reactions) and/or systemic (fatigue, headache, myalgia, arthralgia, chills and fever) post-vaccination adverse reactions. An average 100-fold increase in antibody titre in naive vaccinees was observed between the two time points (median 67 U/mL vs 2841 U/mL, p<0.001). Participants aged below 50 had higher antibody titres (median 99 U/mL vs 26 U/mL, p=0.003 after the first dose; median 3617 U/mL vs 2556 U/mL, p=0.026 after the second dose). All reported adverse reactions were mild-to-moderate, with more participants declaring systemic reactions after the second dose (p=0.001), without a clear correlation with antibody titre., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2022. No commercial re-use. See rights and permissions. Published by BMJ.)

The present study aimed to clarify unusual total antibody kinetics in three female individuals observed during longitudinal monitoring of antibody response to BNT162b2 COVID-19 vaccine in 54 healthy volunteers. Total and IgG antibodies against the SARS-CoV-2 spike glycoprotein were measured using Roche and Abbott quantitative assays, respectively, a day before and 8, 71, 135 and 217 days after the second dose. Samples showing unusual kinetics were additionally tested with Beckman Coulter and Euroimmun IgG assays, as well as IgA assay. Antibody levels peaked 8 days after the second dose (total:2769 U/mL; IgG:20022 AU/mL) and declined to 611 U/mL (total) and 783 AU/mL (IgG), after 217 days. A delayed increase of total but not IgG antibodies evidenced in three females, was in two cases coupled with an increase in IgA antibodies. This study identified a previously unknown contribution of anti-SARS-CoV-2 IgA antibodies to a delayed total antibody increase in a subgroup of vaccinated individuals. It also emphasizes that different commercially available serological assays do not provide uniform information about the post-vaccination immune status and that thorough understanding the assays' features is crucial for the proper interpretation of antibody response monitoring.

The present study aimed to assess the association of 16 polymorphisms in genes encoding prothrombotic and cardiovascular risk factors with COVID-19 disease severity: FV G1691A, FV H1299R, FII G20210A, MTHFR C677T, MTHFR A1298, factor XIII V34L, PAI-1 4G/5G, EPCR haplotypes (A1/A2/A3), eNOS -786 T > C, eNOS G894T, LTA C804A, ACE I/D, ITGB3 PIA1/A2, ITGA2B Baka/b, β-Fbg -455 G > A and ApoB R3500Q. The study included 30 patients with severe COVID-19 and 49 non-severe COVID-19 patients. All studied polymorphisms except ITGA2B Baka/b were determined using multilocus genotyping assays CVD StripAssays (ViennaLab Diagnostics), while ITGA2B was genotyped using a real-time PCR method based on TaqMan technology. A higher frequency of carriers of at least one ITGB3 PIA2 allele was found in severe COVID-19 patients (p = 0.009). The distribution of genotypes was significantly different for ß-Fbg -455 G > A (p = 0.042), with only three homozygous AA genotypes found among severe COVID-19 patients. The association with an increased risk for severe COVID-19 was found for ITGB3, with carriers of at least one ITGB3 PIA2 allele having a 3.5-fold greater risk of severe COVID-19 (p = 0.011). Genotype distribution differences were obtained for the combinations of FV H1299R and FXIII V34L (p = 0.026), ITGB3 PIA1/A2 and ITGA2B Baka/b (p = 0.024), and ACE I/D and PAI-1 4G/5G (p = 0.046). ITGB3 polymorphism emerged as an independent risk factor for severe COVID-19 and homozygosity for ß-Fbg -455 G > A mutation could contribute to disease severity. The combined effect of polymorphisms in genes encoding prothrombotic and cardiovascular risk factors could further contribute to disease severity., (© 2022 Wiley Periodicals LLC.)

The aim of this study was to perform the analytical validation of Alinity c and i analyzers (Abbott Laboratories, Chicago, IL, USA) for 39 clinical chemistry tests and 17 immunoassays. Precision was evaluated at least at two concentration levels for 5 days in quintuplicate, following CLSI EP15-A3. Method comparison included parallel analysis of leftover routine samples on Alinity analyzers and the previously used Cobas c501 and e601 (Roche Diagnostics, Mannheim, Germany). Linearity was tested by preparing sequential sample dilutions with high analyte concentration, following the CLSI EP6 document. For clinical chemistry tests, within-run coefficients of variation (CV) were up to 6.0% (beta-2-microglobulin), while between-run CVs up to 5.4% (immunoglobulin M). Among immunoassays, the highest within-run CV was obtained for vitamin B12 (6.9%), while between-run for CA 19-9 (4.3%). Complete agreement with Roche analyzers was observed for 16 (41%) clinical chemistry assays and 6 (35%) immunoassays. Half of all evaluated assays did not meet the desirable biological variation criteria for bias, being especially exceeded for alpha1-antitrypsin, apolipoprotein A1, ceruloplasmin, complement C3 and C4, hemoglobin A1c, lipoprotein (a) and myoglobin, as well as some tumor markers (CA 125, CEA, fPSA, AFP, and ferritin), hormones (cortisol, DHEA-S, insulin) and vitamins (25-OHD). Linearity in the tested ranges was confirmed. Overall, this study revealed that precision criteria derived from manufacturer's claims were not satisfied for all assays while comparison study for some assays yielded differences that imply the need for additional assay evaluation prior to introduction into routine practice.

Aim: To identify the von Willebrand factor (VWF) gene variant status in Croatian adult patients diagnosed with von Willebrand disease (VWD), provide differential diagnosis of VWD subtypes, and identify patients with mild hemophilia A (HA) who were earlier misdiagnosed as VWD., Methods: Coagulation testing included determination of VWF gain-of-function mutant glycoprotein Ib binding activity (VWF:GPIbM), VWF antigen, VWF collagen-binding activity, and multimeric analysis. Genetic analysis of VWF and FVIII genes was performed with next-generation sequencing (NGS)., Results: The study enrolled 50 patients (72% women; median age 37 years, range 18-75) from 44 unrelated families. Fourteen patients were heterozygous for VWF gene variants compatible with type-1 VWD. Twelve had variants associated with type 2, of whom seven were classified as type 2A, four as type 2B, and one as type 2N. Six type-3 VWD patients were either homozygotes for null variants or combined heterozygotes. Eleven variants within the VWF gene were novel. Three female patients had variants within the FVIII gene, and were re-classified as mild-HA carriers, of whom one had causative novel variants both within VWF and FVIII genes. Fifteen patients remained without a defined genetic cause of their disorder, of whom five had VWF:GPIbM levels below 50%., Conclusion: Croatian adult patients with VWD have considerable genetic heterogeneity. NGS of both VWF and FVIII genes provided accurate differential diagnosis of VWD subtypes and distinction of VWD from mild HA.

This study tried to investigate the impact of oXiris filter on both clinical and laboratory parameters in critically-ill COVID-19 intensive care unit (ICU) patients receiving extracorporeal blood purification and the clinical setting for the initiation of therapy. A consecutive sample of 15 ICU patients with COVID-19 was treated with oXiris membrane for blood purification or for support of renal function due to acute kidney injury. We have included 19 non treated ICU COVID-19 patients as a control group. Two chest x-rays were analyzed for determining the chest x-ray severity score. We have found a significant decrease of SOFA score, respiratory status improved and the chest x-ray severity score was significantly decreased after 72 h of treatment. IL-6 significantly decreased after 72 h of treatment while other inflammatory markers did not. Respiratory status in the control group worsened as well as increase in SOFA score and chest x-ray severity score. Survived patients have shorter time from the onset of symptoms before starting with extracorporeal blood purification treatment and shorter time on vasoactive therapy and invasive respiratory support than deceased patients. Critically-ill patients with COVID-19 treated with extracorporeal blood purification survived significantly longer than other ICU COVID-19 patients. Treatment with oXiris membrane provides significant reduction of IL-6, leads to improvement in respiratory status, chest x-ray severity score, and reduction of SOFA score severity. Our results can suggest that ICU COVID-19 patients in an early course of a disease could be potentially a target group for earlier initiation of extracorporeal blood purification., (© 2021 International Society for Apheresis, Japanese Society for Apheresis, and Japanese Society for Dialysis Therapy.)

Introduction: Based on the hypothesis that there is a substantial rate of adults with prediabetes and undiagnosed diabetes mellitus (DM), our aim was to perform haemoglobin A1c (HbA 1c )-based screening in a cohort of Croatian adults and estimate the prevalence of prediabetes and undiagnosed DM according to American Diabetes Association criteria., Materials and Methods: This multi-center, cross-sectional study performed in six Croatian hospitals included 5527 patients aged 40 to 70 years admitted to the Emergency Department or undergoing a primary care check-up. Haemoglobin A1c was measured from leftover whole blood samples using the enzymatic method on either Alinity c or Architect c-series analyser (Abbott Laboratories, Chicago, USA). Haemoglobin A1c between 39-47 mmol/mol was classified as prediabetes, while ≥ 48 mmol/mol as undiagnosed DM., Results: After exclusion of 435 patients with known DM, the final cohort included 5092 patients (median age 57; 56% males). A total of 882 (17.3%) patients had HbA 1c values between 39 and 47 mmol/mol. There were 214 (4.2%) patients with HbA 1c ≥ 48 mmol/mol. Prediabetes prevalence ranged from 14.2% to 20.5%, while undiagnosed DM from 3.3% to 7.3%, with statistically significant differences among settings (P < 0.001). Age-stratified analysis showed that prediabetes and undiagnosed DM prevalence increase with age (P < 0.001), being 25.4% and 5.8%, respectively, in patients aged 60 to 70 years., Conclusion: Underlying impairment of glucose metabolism was identified in about one in five adults, with significant number of patients with already overt DM. These results should serve as a starting point for further steps directed towards promotion of preventive measures for DM in Croatia., Competing Interests: Potential conflict of interest None declared., (Croatian Society of Medical Biochemistry and Laboratory Medicine.)

Introduction: This study reevaluated von Willebrand disease (vWD) diagnosis in a Croatian paediatric cohort by combining bleeding scores (BS), phenotypic laboratory testing, and next-generation sequencing (NGS)., Materials and Methods: A total of 25 children (11 males and 14 females, median age 10 years, from 2 to 17) previously diagnosed with vWD were included. BS were calculated using an online bleeding assessment tool. Phenotypic laboratory analyses included platelet count, platelet function analyser closure times, prothrombin time, activated partial thromboplastin time, von Willebrand factor antigen (vWF:Ag), vWF gain-of-function mutant glycoprotein Ib binding activity (vWF:GPIbM), vWF collagen binding activity (vWF:CBA), factor VIII activity (FVIII:C) and multimeric analysis. Next-generation sequencing covered regions of both vWF and FVIII genes and was performed on MiSeq (Illumina, San Diego, USA)., Results: Disease-associated variants identified in 15 patients comprised 11 distinct heterozygous vWF gene variants in 13 patients and one novel FVIII gene variant (p.Glu2085Lys) in two male siblings. Four vWF variants were novel (p.Gln499Pro, p.Asp1277Tyr, p.Asp1277His, p.Lys1491Glu). Three patients without distinctive variants had vWF:GPIbM between 30 and 50%. Patients with identified vWF gene variants had statistically significant lower values of vWF:GPIbM (P = 0.002), vWF:Ag (P = 0.007), vWF:CBA (P < 0.001) and FVIII:C (P = 0.002), compared to those without. Correlations between BS and phenotypic laboratory test results were not statistically significant for either of the tests., Conclusion: The applied diagnostic approach confirmed the diagnosis of vWD in 13 patients and mild haemophilia A in two. Limited utility of BS in the paediatric population was evidenced., Competing Interests: Potential conflict of interest None declared., (Croatian Society of Medical Biochemistry and Laboratory Medicine.)

Objectives: In 2019 The Croatian Working Group for Laboratory Hematology, on behalf of the Croatian Society of Medical Biochemistry and Laboratory Medicine, wanted to explore the background in field of laboratory hematology routine practice among Croatian laboratories in order to develop future strategies for producing national recommendations, if needed., Methods: During April and May 2019, a comprehensive survey covering all main parts of the total testing process within the field of laboratory hematology among Croatian medical laboratories was conducted. The survey comprised 49 inquiries. Data was collected using Survey Monkey (Palo Alto, CA, USA). All collected data was anonymized., Results: The response rate was 72%. There is still a substantial number of laboratories that have only three-part differential hematology analyzers (9%). Furthermore, a very high number of laboratories did not perform analyzer verification prior to implementation into routine work (31%). Out of those who have verified their analyzers, a diversity of guidelines and recommendations were used. Nearly 10% of the laboratories do not have a defined policy regarding specimen rejection. The majority of the participants perform internal quality control daily (83%), however, only 51% of respondents evaluate the agreement between different hematology analyzers on daily basis. Although more than 90% of Croatian laboratories have a defined policy regarding specimen rejection, only 61% of respondents continuously monitor quality indicators in routine practice., Conclusions: The survey revealed substantial differences in all aspects of laboratory hematology practices among Croatian medical laboratories, indicating the need for universal recommendations at the national level., (© 2021 Walter de Gruyter GmbH, Berlin/Boston.)

Aim: To determine the influence of high-efficacy disease modifying therapy (DMT) on the development of IgG SARS-CoV-2 antibody response in COVID-19 convalescent people with multiple sclerosis (pwMS)., Methods: Seventy-four pwMS taking high-efficacy DMTs (specifically natalizumab, fingolimod, alemtuzumab, ocrelizumab, cladribine and ublituximab) and diagnosed with COVID-19 and 44 healthy persons (HC) were enrolled. SARS-CoV2 antibodies were tested with Elecsys® Anti-SARSCoV-2 S assay., Results: pwMS taking high-efficacy DMTs had a significantly higher chance of having negative titer of SARS-CoV2 antibodies compared to healthy controls (33 negative pwMS [44.6%] compared to one negative HC [2.3%], p < 0.001). pwMS taking B-cell depleting therapy (ocrelizumab and ublituximab) had a significantly higher chance of having negative titer of SARS-CoV2 antibodies compared to pwMS on all other DMTs (29 negative pwMS on B-cell therapy [64.4%] compared to four negative pwMS on all other DMTs [13.8%], p < 0.001). Out of other DMTs, two (33.3%) pwMS taking fingolimod and two (16.7%) pwMS taking cladribine failed to develop IgG SARS-COV-2 antibodies. B-cell depleting therapy independently predicted negative titer of IgG SARS-CoV-2 antibody (Exp[B] =0.014, 95%CI 0.002-0.110, p < 0.001)., Conclusions: A significant proportion of convalescent COVID-19 pwMS on high-efficacy DMTs will not develop IgG SARS-CoV-2 antibodies. B-cell depleting therapies independently predict negative and low titer of IgG SARS-CoV-2 antibody., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Transition to new analytical systems and methods requires end-user verification to ensure acceptability for routine use. Our aim was to verify precision of MAGLUMI 800 immunoassay analyzer for 17-hydroxyprogesterone (17-OHP), 25-hydroxy vitamin D (25(OH)D), aldosterone, androstenedione, growth hormone (GH), insulin-like growth factor 1 (IGF-1), insulin-like growth factor-binding protein 3 (IGFBP-3) and renin, as well as to assess their comparability with the routinely used assays. Precision was evaluated at two levels following the CLSI EP15-A2 protocol. Method comparison included parallel analysis of 40 routine samples for each assay on MAGLUMI 800 and the routinely used automated or manual immunoassays. Within-run coefficients of variation (CV) ranged from 0.8% (androstenedione) to 14.5% (aldosterone), between-run CVs from 1.0% (IGFBP-3) to 12.8% (renin), while within-laboratory (total) precision CVs were from 2.1% (IGFBP-3) to 14.9% (renin). All assays with the exception of IGF-1 and 25(OH)D at the low concentration control level, satisfied biological variation criteria for imprecision. Passing-Bablok regression showed proportional difference for 17-OHP and aldosterone, constant for androstenedione, while both constant and proportional difference was revealed for 25(OH)D, GH and IGF-1. Statistically significant relative biases higher than the desirable biological variation acceptance criteria were observed for 17-OHP, 25(OH)D, aldosterone, androstenedione and IGF-1. The evaluated assays need further assessment as well as verification of reference intervals in order to be suitable for introduction into routine practice in our laboratory. Our study clearly demonstrates that we are still far from achieving immunoassay standardization and comparability of results.

Introduction: Effective implementation and continual compliance with ISO 15189:2012 require ongoing commitment and active involvement of laboratory staff. Our aim was to assess attitudes regarding accreditation implementation by conducting a survey in three Croatian accredited medical laboratories., Materials and Methods: An anonymous survey consisting of 34 questions was distributed either electronically or in a paper form a week prior to scheduled annual audits. Distributions of answers regarding age, work experience, laboratory workplace, and education level and according to the respective laboratory were compared., Results: The overall response rate was 76% (225/297). Preference towards working in an accredited laboratory and a positive attitude were revealed by 70% and 56% participants, respectively, with better process documentation as the main advantage. Only 14% of responders considered themselves completely familiar with ISO 15189:2012. Total of 68% of responders felt that accreditation increases the usual workload, with excessive paperwork as the main contributor. Half of the responders declared partial agreement that accreditation requirements and expectations were clearly explained and claimed that their suggestions were taken into account only occasionally, which was especially emphasized by technical staff. The vast majority (89%) completely follow the prescribed protocols. Only 27% consider turnaround time monitoring useful. Competence assessment is considered efficient by 41% of responders. The majority (73%) prefer an online audit in times of COVID-19., Conclusions: Despite an overall positive attitude towards accreditation, further efforts are needed in providing better education about ISO 15189:2012 for technical staff and modifying formats of competence assessment, in order to achieve better adherence to ISO 15189:2012 requirements., Competing Interests: Potential conflict of interest None declared., (Croatian Society of Medical Biochemistry and Laboratory Medicine.)

Objectives: Philadelphia-negative chronic myeloproliferative neoplasms (MPNs), essential thrombocythemia (ET), polycythemia vera (PV) and myelofibrosis (MF), are characterized by clonal myeloproliferation and a strong inflammatory atmosphere. YKL-40, expressed in granulocytes, macrophages, megakaryocytes and malignant cells, is an acute phase reactant with an important role in tissue remodeling and atherosclerotic inflammation. The aim of this study was to investigate serum YKL-40 levels in MPNs and to assess its clinical correlations. Methods: ELISA test was used to measure serum YKL-40 levels in 111 MPN patients and in 32 healthy controls. Results: Serum YKL-40 levels were higher in ET, post-ET MF, PV, post-PV MF and primary MF patients, when compared to healthy controls (p < 0.001). Higher serum YKL-40 levels were associated with parameters indicative of the increased inflammatory state (higher C-reactive protein, poor performance status, presence of constitutional symptoms and cardiovascular risk factors). Additionally, higher serum YKL-40 levels in MF patients were associated with blast phase disease, lower hemoglobin and higher Dynamic International Prognostic Scoring System score. In the multivariate Cox regression models, higher serum YKL-40 levels in ET and PV patients were independently associated with an increased risk of thrombosis (HR 4.64, p = 0.031) and impaired survival in MF patients (HR 4.31, p = 0.038). Conclusion: These results indicate that higher circulating YKL-40 levels in MPNs might have a pathophysiological role in disease progression and thrombosis development. Assessing circulating YKL-40 could help in identification of ET and PV patients at a high risk of future cardiovascular events and has a good potential for improving prognostication of MF patients.

Philadelphia-negative myeloproliferative neoplasms (MPNs), essential thrombocythemia (ET), polycythemia vera (PV), and myelofibrosis (MF), are rare clonal hematopoietic stem cell disorders accompanied by a strong inflammatory milieu, which is directly responsible for constitutional symptoms associated with the disease, such as fever, weight loss or night sweats. Non-hematologists sometimes (and often wrongly) consider the fever in MPN patients to be a symptom of an underlying disease, which may have devastating consequences. Serum procalcitonin (PCT) is a circulating biomarker commonly used to improve the diagnostic accuracy of bacterial infections and to guide antibiotic therapy. The aim of this study was to test whether PCT could aid the clinician in the early diagnosis of bacterial infections in MPNs. This study investigated PCT in 41 ambulatory MPN patients (13 ET, 13 PV and 15 MF) who had no signs of infection and compared it to 10 MPN patients with microbiologically and/or serologically documented bacterial infections. Median PCT in MPN patients was 0.02 ng/mL (range 0.01-0.09 ng/mL). No difference in PCT was found between ET, PV and MF patients (p = 0.993), whereas MPN patients with documented bacterial infections had significantly higher PCT (median PCT 2.45, range 0.90-5.40 ng/mL) when compared to MPN patients with (median PCT 0.03 ng/mL) or without constitutional symptoms (median PCT 0.02 ng/mL; p < 0.001 for both analyses). These results clearly show that PCT should not be considered as a disease biomarker in MPNs and careful clinical assessment for the signs of infection is needed when MPN patients present with fever and high PCT.

Aim: To evaluate three fully automated serological assays in terms of reactivity to SARS-CoV-2 immunoglobulin G (IgG) and perform SARS-CoV-2 IgG antibody testing among asymptomatic health care workers (HCW) at the University Hospital Center Zagreb., Methods: Three IgG serological assays (Abbott SARS-CoV-2 IgG, Elecsys Anti-SARS-CoV-2, and MAGLUMI 2019-nCoV IgG) were initially evaluated by analyzing 42 samples from confirmed COVID-19-recovered patients and 48 negative individuals. A total of 1678 HCW (~30% of all hospital employees) were screened for SARS-CoV-2 IgG with the Abbott assay, run on Abbott Architect i2000SR. The samples exceeding the predefined cut-off (1.4 S/C) were reanalyzed with the Elecsys, MAGLUMI, and VIDAS SARS-COV-2 IgG assays., Results: Initially, the MAGLUMI 2019-nCoV IgG produced 26.2% false negatives and the Elecsys Anti-SARS-CoV-2 produced one false positive. Among 1678 HCW, the Abbott assay showed only 10 (0.6%) positive results, with mostly mildly elevated signals. Nine of these samples were non-reactive when they were retested with the Elecsys, MAGLUMI, and VIDAS assays. As for the one remaining sample, it was positive when tested with the Elecsys assay, while the other two assays yielded negative results., Conclusions: SARS-CoV-2 IgG seroprevalence among asymptomatic HCW in our hospital setting was low, with different assays indicating a different number of positive samples. One of the assays yielded a large false negative rate. These findings can be attributed to differences in assay formulation but also to heterogeneity and diverse reactivity of antibodies against SARS-CoV-2 antigens.

Objective: Reorganization of the emergency department (ED) during the COVID-19 pandemic implied closure of the ED-dedicated laboratory and manual transport of all specimens to the dislocated central laboratory. The impact of such reorganization on laboratory turnaround time (TAT) was examined., Methods: The TAT from blood sampling to specimen reception (TAT1), from specimen reception to test reporting (TAT2), and from sampling to test reporting (TAT3) were compared between the pandemic peak month in 2020 and the same month in 2019. We evaluated whether TAT2 fulfills the recommended 60-minute criteria., Results: A statistically significant difference was observed for all comparisons (P <.001), with TAT1 prominently contributing to TAT3 prolongation (from 48 minutes to 108 minutes) and exceeding the recommended 60-minute criteria. The TAT2 was extended from 33 minutes to 49 minutes., Conclusion: An ED reorganization compromised the usual laboratory services for patients in the ED, with manual specimen delivery being the main cause for TAT prolongation., (© American Society for Clinical Pathology 2020. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Introduction: The aim of the study was the analytical verification of automated latex-enhanced particle immunoturbidimetric (LPIA) D-Dimer assay INNOVANCE D-dimer on Sysmex CS-5100 and Atellica COAG 360 analysers, and HemosIL D-dimer HS500 on ACL TOP 550, as well as the comparison with the enzyme-linked immunofluorescent assay (ELFA) on the miniVidas analyser., Materials and Methods: Verification included assessment of within-run and between-run precision, bias, measurement uncertainty (MU), verification of the cut-off, method comparison between all assessed assays, and the reference commercial ELFA VIDAS D-Dimer Exclusion II., Results: Within-run coefficients of variations (CVs) ranged from 1.6% (Atellica COAG 360) to 7.9% (ACL TOP 550), while between-run CVs ranged from 1.7% (Sysmex CS-5100) to 6.9% (Atellica COAG 360). Spearman's rank correlation coefficients were > 0.99 between LPIAs and ≥ 0.93 when comparing ELFA with LPIA. Passing-Bablok regression analysis yielded constant and proportional difference for comparison of ACL TOP 550 with both Sysmex CS-5100 and Atellica COAG360, and for miniVidas with Atellica COAG360. Small proportional difference was found between miniVidas and both Sysmex CS-5100 and ACL TOP 550. Calculated MUs using D-dimer HS 500 calibrator were 12.6% (Sysmex CS-5100) and 15.6% (Atellica COAG 360), while with INNOVANCE D-dimer calibrator 12.0% (Sysmex CS-5100), 10.0% (Atellica COAG 360) and 28.1% (ACL TOP 550). Excellent agreement of results was obtained, with occasional discrepancies near the cut-off. The cut-off (0.5 mg/L FEU) was confirmed., Conclusions: The obtained results prove satisfactory analytical performance of LPIAs, their high comparability and almost equal discriminatory characteristics, suggesting them as a valid alternative to ELFA., Competing Interests: Potential conflict of interest None declared., (Croatian Society of Medical Biochemistry and Laboratory Medicine.)

Temporomandibular disorders (TMD), when progress to a chronic state, might contribute to psychosocial or psychological distress. This study aimed to evaluate the effect of stabilization splint (SS) therapy on pain, pain-related disability and psychological traits of chronic TMD patients, as well as to assess selected oxidative stress (OS) biomarkers during 6-month treatment and associate them with the symptoms of anxiety and depression. Thirty-four participants were randomly assigned into two treatment groups [SS and placebo splint (PS)]. Primary outcomes were pain intensity and pain-related disability while secondary outcomes included depressive and anxiety symptoms. The influence of the treatment type was analyzed with regards to the levels of OS biomarkers in saliva. Participants treated with SS demonstrated significantly greater improvement in pain-related disability (Pain-free mouth opening: p = 0.018, η 2  = 0.166; Number of disability days: p = 0.023, η 2  = 0.155) and greater reduction of depressive symptoms scores (p = 0.007, η 2  = 0.207). When compared to the PS group, participants in the SS group showed a significant reduction of oxidant/antioxidant ratio (p = 0.018, η 2  = 0.167) at a 3-month follow-up. A stabilization splint provides advantages over PS in the treatment of depressive symptoms and pain-related disability. Furthermore, clinical success in terms of reduction of depressive symptoms, which correlates with the reduction of oxidative stress markers in the SS group, indicates that oxidative stress is related to psychological factors in chronic TMD patients.

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., (© 2019 John Wiley & Sons Ltd.)

Objectives: To assess the diagnostic accuracy of erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) in acute inflammation., Methods: PubMed and Scopus were searched and eligible articles were screened for methodologic quality using the Quality Assessment of the Diagnostic Accuracy Studies-Revised. Meta-analysis with calculation of pooled sensitivity (Se), specificity (Sp), and summary area under the curve (SAUC) was performed., Results: Twenty-nine studies were eligible. Se and Sp were 0.78 and 0.68 (SAUC = 0.80) for ESR in orthopedic infections and 0.79 and 0.70 (SAUC = 0.81) for CRP. For the diagnosis of other various inflammatory conditions, CRP had a superior diagnostic accuracy, with a Se of 0.86, Sp of 0.67, and SAUC of 0.86 compared with a Se of 0.77, Sp of 0.59, and SAUC of 0.75 for ESR. Heterogeneity among studies was elevated. Combined use of ESR and CRP yielded higher diagnostic accuracy., Conclusions: Despite observed heterogeneity among studies, ESR and CRP have a similar diagnostic accuracy in assessment of inflammation, especially in orthopedic conditions., (© American Society for Clinical Pathology, 2019. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Introduction: Inappropriate laboratory retesting can be addressed by implementing minimum retesting intervals (MRI). The aim of our study was to assess the effectiveness of the implemented MRI protocol for inpatients., Materials and Methods: Minimum retesting intervals were applied for 53 laboratory tests. The overall reduction of test requests, reduction in charges and reagent cost savings, frequency of MRI alert appearance as well as the rate of MRI acceptance and ignorance were calculated for a one-year period. Reasons for violating the MRI rule, hospital departments that contributed mostly to MRI rule violation, and the frequency of MRI violations between routine and emergency laboratory were evaluated., Results: During the one-year period, 106,780 requests violated the MRI rule, which corresponds to 14.8% of all requests received. 13,843 requests were cancelled, yielding a 1.9% reduction of requested tests. High-volume tests, namely complete blood count, C-reactive protein, alanine aminotransferase, gamma-glutamyltransferase and total bilirubin, accounted for 65% of all generated alerts and had the highest alert ignorance (>85%). The highest cancellation rate was observed for tumor markers and autoimmunity tests, for most being at least 50%. Annual charge reduction was 62,641 EUR while reagent cost savings were 11,408 EUR. Tests performed in the emergency laboratory had a higher alert appearance than the same routine tests. The most common reason for MRI violation was clinical justification based on the patient's condition. Most frequently ignored MRI alerts were in the intensive care unit., Conclusion: MRI implementation showed limited effectiveness in reducing testing repetition and achieving financial savings, yet provided the basis for future improvements., Competing Interests: Potential conflict of interest: None declared., (©Croatian Society of Medical Biochemistry and Laboratory Medicine.)

Ves-Matic CUBE 200 is an automated erythrocyte sedimentation rate (ESR) analyser based on the modified Westergren principle of measurement. In this study, we aimed to assess its analytical performance following the key points addressed by the International Council for Standardization in Haematology and the comparability with the gold standard Westergren method. Comparison of the two methods yielded a correlation coefficient of 0.852, no significant bias and a small constant difference between compared results. Intrarun coefficients of variation (CV) ranged from 2.2% to 22.2%, the higher being for lower ESR values, while inter-run CVs were 19.7% for the normal range and 3.0% for the abnormal range. This study proved the analytical validity of the Ves-Matic CUBE 200 and its high comparability with the Westergren method, showing obvious improvements in the technology applied for automated determination of ESR and a valuable step forward in standardisation of ESR methods., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

Background Development of automated analyzers for erythrocyte sedimentation rate (ESR) has imposed the need for extensive validation prior to their implementation in routine practice, to ensure comparability with the reference Westergren method. The aim of our study was to perform the analytical validation of two automated ESR analyzers, the Ves-Matic Cube 200 and the TEST1. Methods Validation was performed according to the recent International Council for Standardization in Hematology recommendations and included determination of intrarun and inter-run precision, assessment of sample carryover, hemolysis interference, sensitivity to fibrinogen, method comparison with the gold standard Westergren method and stability test. Results The highest intrarun imprecision was obtained for the low ESR range (33.5% for Ves-Matic Cube; 37.3% for TEST1) while inter-run coefficients of variation on three levels were much better for the TEST1 (0%, 2% and 1.2%) compared to the Ves-Matic Cube 200 on two levels (24.9% and 5.8%). Both Ves-Matic Cube 200 and TEST1 showed no statistically significant difference when compared with Westergren. Bland-Altman analysis yielded overall insignificant mean biases for all comparisons, but a wider dispersion of results and 95% limits of agreement for comparisons including the Ves-Matic Cube 200. Carryover was considered insignificant, while hemolysis had a negative effect on all assessed ESR methods. The highest sensitivity to fibrinogen was observed for the Ves-Matic Cube 200, followed by Westergren and the least sensitive was the TEST1. Conclusions The obtained results proved the analytical validity of the TEST1 and the Ves-Matic Cube 200, and high comparability with the gold standard Westergren method, showing obvious improvements in standardization of ESR methods.