Standardization and harmonization in hematology: Instrument alignment, quality control materials, and commutability issue

In the hub and spoke laboratory network, the number of hematology analyzers (HAs) within each core center has increased, and the control of HAs alignment is becoming necessary requirement to ensure analytical quality. In this scenario, HA alignment can be assessed by analyzing the same control material used for internal quality control on multiple HAs, assuming its commutability. The aim of the study was to verify the applicability of a protocol for the alignment of HAs based on control material rather than on fresh whole-blood samples

Complete Blood Count as point of care testing QBC STAR\u2122: Preliminary evaluation

Introduction: Point of care testing (POCT) represents a valuable option when laboratory data shall be urgently available for timely clinical management, with a turnaround time (TAT) that is unfeasible using conventional laboratory instrumentation. This study was aimed to compare the performance of QBC STAR\u2122 compared to Sysmex XN-module and the reference optical microscopy (OM) assessment. Material and methods: One hundred peripheral blood samples, collected in K3 EDTA tubes, and 50 capillary blood samples obtained by finger stick were analyzed with QBC STAR\u2122, Sysmex XN-module, and OM. Data were compared with Passing-Bablok regression and Bland-Altman plots. Results: The Passing-Bablok regression analysis (QBC STAR\u2122 capillary sample vs XN-module) yielded slopes comprised between 0.30 and 1.37, while the intercepts ranged between -17.57 and 232.6. Bland-Altman plots yielded relative bias comprised between -4.87% (for MN QBC STAR\u2122 capillary sample vs XN-module) and 27% (PLT QBC STAR\u2122 capillary sample vs XN-module). A significant bias was found for all parameters except MN and WBC, RBC in all and pediatric samples, and HB in adults samples. Conclusion: The results of this analytical evaluation suggest that QBC STAR\u2122 may not be the ideal tool for performing complete blood count analysis for diagnostic purposes, while it could be more useful in urgent/emergent conditions, such as for rapid monitoring of some hematological parameters (eg, WBC and HB)

Assessment of the analytical performance of novel parameters of automated blood count on Sysmex XN-9000.

Recent technological advancements in laboratory hematology have promoted the introduction of many innovative parameters, which have the potential to enhance the clinical efficiency of this diagnostic area. This study aimed to assess the analytical performance of some of these new parameters available on Sysmex XN-9000 according to the International Council for Standardization in Haematology (ICSH) guidelines. Our evaluation included the assessment of imprecision (both intra- and inter-assay), carryover, sample stability and comparison with optical microscopy. The new red blood cell and platelet parameters displayed CV comprised between 0.7% and 34.6%. The new leukocyte parameters immature granulocyte (IG), hight fluorescence cell and cell population data (CPD) were characterized by CV ranging from 1% to 24%. Carryover was negligible for all parameters. Samples stability showed different trends for the different parameters, especially for CPD, depending on temperature and time of testing. The comparison of IG and nucleated red blood cell (NRBC) enumeration determined with Sysmex XN-9000 and optical microscopy yielded Pearson\u2019s correlation coefficients comprised between 0.82 and 0.99. The absolute bias was 0.83% and -0.06% for IG and NRBC, respectively. The results of this evaluation show that the innovative parameters available on Sysmex XN-9000 display, with some exceptions, acceptable performance, in line with data obtained with other analyzers. The results of sample stability studies are helpful to identify the best storage conditions for these parameters

Assessment of blood sample stability for complete blood count using the Sysmex XN-9000 and Mindray BC-6800 analyzers

Different hematological analyzers have different analytical performances that are often reflected in the criteria for sample stability of the complete blood count. This study aimed to assess the stability of several hematological parameters using the XN-9000 Sysmex and BC-6800 Mindray analyzers

Identification of Human SARS-CoV-2 Monoclonal Antibodies from Convalescent Patients Using EBV Immortalization

We report the isolation of two human IgG1k monoclonal antibodies (mAbs) directed against the SARS-CoV-2 spike protein. These mAbs were isolated from two donors who had recovered from COVID-19 infection during the first pandemic peak in the Lombardy region of Italy, the first European and initially most affected region in March 2020. We used the method of EBV immortalization of purified memory B cells and supernatant screening with a spike S1/2 assay for mAb isolation. This method allowed rapid isolation of clones, with one donor showing about 7% of clones positive against spike protein, whereas the other donor did not produce positive clones out of 91 tested. RNA was extracted from positive clones 39–47 days post-EBV infection, allowing VH and VL sequencing. The same clones were sequenced again after a further 100 days in culture, showing that no mutation had taken place during in vitro expansion. The B cell clones could be expanded in culture for more than 4 months after EBV immortalization and secreted the antibodies stably during that time, allowing to purify mg quantities of each mAb for functional assays without generating recombinant proteins. Unfortunately, neither mAb had significant neutralizing activity in a virus infection assay with several different SARS-CoV-2 isolates. The antibody sequences are made freely available

Assessment of blood sample stability for complete blood count using the Sysmex XN-9000 and Mindray BC-6800 analyzers

ABSTRACT BACKGROUND: Different hematological analyzers have different analytical performances that are often reflected in the criteria for sample stability of the complete blood count. This study aimed to assess the stability of several hematological parameters using the XN-9000 Sysmex and BC-6800 Mindray analyzers. METHODS: The impact of storage at room temperature and 4 °C was evaluated after 2, 4, 6, 8, 24, 36 and 48 h using ten normal and 40 abnormal blood samples. The variation from the baseline measurement was evaluated by the Steel-Dwass-Critchlow-Fligner test and by Bland-Altman plots, using quality specifications and critical difference as the total allowable variation. RESULTS: Red blood cells and reticulocyte parameters (i.e. hematocrit, mean corpuscular volume, mean corpuscular hemoglobin concentration, red blood cell distribution width, immature reticulocyte fractions, low-fluorescence reticulocytes, middle-fluorescence reticulocytes, high fluorescence mononuclear cells) showed less stability compared to leukocyte and platelet parameters (except for monocyte count and mean platelet volume). The bias for hematocrit, mean corpuscular volume, mean corpuscular hemoglobin concentration and red blood cell distribution width coefficient of variation was higher than the critical difference after 8 h using both analyzers. CONCLUSION: Blood samples measured with both analyzers do not show analytically significant changes in up to 2 h of storage at room temperature and 4 °C. However, the maximum time for analysis can be extended for up to 8 h when the bias is compared to the critical difference

Impact of SARS-CoV-2 Omicron and Delta variants in patients requiring intensive care unit (ICU) admission for COVID-19, Northern Italy, December 2021 to January 2022

This multicenter observational study included 171 COVID-19 adult patients hospitalized in the ICUs of nine hospitals in Lombardy (Northern Italy) from December, 1st 2021, to February, 9th 2022. During the study period, the Delta/Omicron variant ratio of cases decreased with a delay of two weeks in ICU patients compared to that in the community; a higher proportion of COVID-19 unvaccinated patients was infected by Delta than by Omicron whereas a higher rate of COVID-19 boosted patients was Omicron-infected. A higher number of comorbidities and a higher comorbidity score in ICU critically COVID-19 inpatients was positively associated with the Omicron infection as well in vaccinated individuals. Although people infected by Omicron have a lower risk of severe disease than those infected by Delta variant, the outcome, including the risk of ICU admission and the need for mechanical ventilation due to infection by Omicron versus Delta, remains uncertain. The continuous monitoring of the circulating SARS-CoV-2 variants remains a milestone to counteract this pandemic