Band 49, Heft 4

Objectives A variety of methods are currently used to measure von Willebrand factor (VWF) activity, but still the VWF ristocetin cofactor (VWF:RCo) assay using the manual aggregometry technique is the reference method, even having high inter-laboratory variability. The automated coagulation analyzers offer several advantages for routine testing. Herein the performance of the automated Sysmex CS2000/2100i analyzer was compared to the manual aggregometer Chrono-log 700 for assessing VWF:Co activity in patients suspected of having von Willebrand disease (VWD). Methods Plasma samples from 136 patients were prospectively collected, and blindly analyzed on both instruments, simultaneously. Linear regression analysis, Bland-Altman test, intra-class correlation coefficient (ICC), and area under receiver-operator characteristic (ROC) curve were used to evaluate the performance of the automated VWF:RCo assay. Results There was a strong positive correlation between the two assays (r=0.86, p<0.0001) with an excellent reliability ICC value of 0.81 (95 % CI: 0.74–0.86). A very good degree of agreement between the two assays was also evidenced with an estimated bias of −0.055 (−0.58 to 0.46). The ROC curve for the automated VWF:RCo assay was 0.86 (95 % CI: 0.78–0.92; p<0.0001). Using a cut-off value of 0.44 UI/mL for VWF:RCo activity, the sensitivity and specificity values were 91.2 %, and 88.2 % for the automated assay. The positive and negative positive values for VWD detection were 72.9 %, and 96.7 %, respectively. Conclusions Collectively, these findings indicate that the automated VWF:RCo assay yields comparable results to the manual aggregometry assay, with very good accuracy and precision to help diagnose patients suspected with VWD.

Objectives Hemolysis in laboratory samples is a frequent error that may lead to clinical misinterpretation and incorrect patient treatment. Thus, modern laboratory analyzers are able to assess the hemolysis index (HI). To prevent reporting of erroneous results, manufacturers are obliged to provide reliable HI threshold values. The aim of this study was to proof the quality of manufacturer’s given HI thresholds. Methods Dilution series with defined degrees of hemolysis were prepared by using blood samples from voluntary participants (n=77). In addition to the HI in each dilution, 18 measurands, namely sodium, potassium, chloride, aspartate aminotransferase (ASAT), alanine aminotransferase (ALAT), gamma-glutamyl transferase (GGT), lactate dehydrogenase (LDH), haptoglobin, total bilirubin, direct bilirubin, glutamate dehydrogenase (GLDH), creatine kinase (CK), iron, amylase, phosphate, total protein, enzymatic creatinine and high-sensitive troponin T, were measured on a cobas ® pro analyzer. Thresholds for maximum deviation of measurement results of 5 , 10 and 20 % were calculated. Then we determined cut-offs as the 5th percentile and median. Results Using potassium as an example we found HI thresholds at 57 (5th percentile) and 70 (median) with a corresponding result deviation of 5 % while the manufacturer HI threshold is given at 20. Thus, a higher HI threshold might be tolerated. Conclusions We established HI thresholds for 18 biochemistry assays. Eight assays showed considerable deviations of which six may have potential clinical relevance like potassium and high-sensitive troponin T. Optimizing thresholds can help to reduce the risk of unnecessary blocking of results and preventing considerably impaired results from being released.

Objectives Kawasaki disease (KD) is a systemic vasculitis that results in abnormalities in the coronary arteries. Podoplanin (PDPN) and its receptor C-type lectin-like receptor 2 (CLEC-2) are involved in inflammatory hemostasis and have also been proved to be effective predictive markers for early evaluation of sepsis and coagulation. This study aimed to investigate the expression of PDPN and its receptor CLEC-2 in the patients with KD, and evaluate the relationship between PDPN and clinical laboratory parameters. Methods Plasma samples were obtained from a cohort of 63 patients diagnosed with KD and 31 healthy children. Patients with KD were further categorized into two groups: KD with coronary artery lesions (KD-CALs) and KD non-coronary artery lesions (KD-NCALs). The plasma levels of PDPN, CLEC-2, and GPVI were quantified using ELISA. Results Our findings indicated that the plasma concentrations of PDPN, CLEC-2, and GPVI were significantly elevated in KD patients compared to the healthy controls. Moreover, positive correlations between plasma PDPN levels and erythrocyte sedimentation rate (ESR), interleukin-6, and D-dimer were observed in the KD-CALs group. Receiver operating characteristic curve analysis showed that the area under the curve of PDPN was 0.8377, with PDPN providing 45.45 % sensitivity and 90.48 % specificity, which proved the value of PDPN as a predictor of CALs in KD. Conclusions The findings suggest that PDPN may play a role in the pathogenesis of KD, and upregulation of PDPN may contribute to the hypercoagulable state observed in KD. Therefore, PDPN could potentially be a diagnostic biomarker for KD.

Objectives Epstein-Barr virus (EBV) is ubiquitous, affecting up to 50 % of children and 90 % of adults globally. This study aimed to investigate the epidemiological characteristics of EBV among children in Hangzhou from 2019 to 2023. Methods From January 2019 to December 2023, all children with suspected EBV-related diseases in Children’s Hospital were enrolled. EBV DNA detection and statistical analysis were conducted. Results A total of 26,592 children were enrolled, of which 2,148 (8.07 %) tested positive for EBV DNA. In comparison to those in the pre‐COVID‐19 period (2019) and during- COVID‐19 period (2020–2022), the prevalence of EBV‐positive children significantly increased to 788 (10.35 %) in post-COVID-19 period (2023) (p<0.001). There was a gender difference in the EBV‐positive rate, with 7.66 % (1,157/15,095) of males and 8.62 % (991/11,497) of females positive (p<0.05). The age distribution of EBV remained an apparent consistent trend from 2019 to 2023, with the peak positive rates all observed in children aged 3–6 years and the lowest in children aged 0–1 year. IM is the most common disease accounting for 50.74 %. Compared to IM, HLH had significantly higher EBV DNA loads, while respiratory infections, leukemia and AA had significantly lower loads (p<0.05). Conclusions This is a large sample and the first comprehensive assessment that reveals the epidemiological characteristics of EBV among children in Hangzhou across the pre-, during- and post-COVID-19 periods, which provide a deeper understanding of EBV epidemiology to inform prevention, diagnosis, and treatment strategies.

Objectives To evaluate the accuracy of mean platelet volume (MPV) testing in the neonatal population and assess the applicability of the optical platelet volume measurement method on Sysmex XN9000 in this demographic. Methods From June 2023 to June 2024, we analyzed complete blood count (CBC) data from 1,070 neonates with infections to assess MPV testing reliability using instrument alerts and histograms. Additionally, 284 neonates without infections or hematologic diseases were included to evaluate the Sysmex optical platelet volume indicator (PLT-F-Y) reliability. Finally, four cases of neonatal sepsis were examined to determine the correlation between PLT-F-Y and neonatal sepsis. Results In neonates with infections, 24.67 % of MPV data did not accurately reflect platelet volume, and this issue was not confined to cases with low platelet counts. The PLT-F-Y indicator demonstrated superior accuracy in measuring platelet volume, with a reference range of approximately 42.6–64.2 mean fluorescence intensity (MFI) for neonates. Additionally, PLT-F-Y correlated with the progression of neonatal sepsis. Conclusions MPV is not a “perfect” indicator for newborns, whereas PLT-F-Y may serve as a potential better alternative.