Abbott D-dimer assay: analytical performance and diagnostic accuracy in management of venous thromboembolism.

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.

Analytical validation of the modified Westergren method on the automated erythrocyte sedimentation rate analyzer CUBE 30 touch.

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.

Association of polymorphisms in genes encoding prothrombotic and cardiovascular risk factors with disease severity in COVID-19 patients: A pilot study.

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, ß-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.

Policies and practices in the field of laboratory hematology in Croatia - a current overview and call for improvement.

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.

Analytical validation of 39 clinical chemistry tests and 17 immunoassays on the Alinity analytical system.

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.

Unusual total anti-SARS-CoV-2 antibody kinetics observed during longitudinal monitoring after BNT162b2 vaccination.

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.

Next-generation sequencing of von Willebrand factor and coagulation factor VIII genes: a cross-sectional study in Croatian adult patients diagnosed with von Willebrand disease.

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.

Preliminary evaluation of eight less frequent endocrine assays designed for MAGLUMI 800 chemiluminescence immunoanalyzer.

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.

The reliability of SARS-CoV-2 IgG antibody testing - a pilot study in asymptomatic health care workers in a Croatian university hospital.

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.

Automated measurement of the erythrocyte sedimentation rate: method validation and comparison.

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.

Are shortened aPTT values always to be attributed only to preanalytical problems?

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.

Exploratory analysis of glial fibrillary acidic protein and ubiquitin C-terminal hydrolase L1 in management of patients with mild neurological symptoms undergoing head computed tomography scan at the emergency department: a pilot study from a Croatian tertiary hospital.

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.

Mixing studies for lupus anticoagulant: does it matter how we mix?

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.

Point of care testing in Croatia: a survey of the Working group for point of care testing of the Croatian society of medical biochemistry and laboratory medicine.

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.

The band count imprecision - a Croatian multicentric pilot study.

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.

The Role of Uroguanylin in Regulation of Ion Transport in Salivary Glands.

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.

Analytical validation of white blood cell differential and platelet assessment on the Sysmex DI-60 digital morphology analyzer.

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.