Prognostic value of cellular population data in patients with COVID-19

Background and aims

Beckman Coulter hematology analysers identify leukocytes by their volume (V), conductivity (C) and scatter (S) of a laser beam at different angles. Each leukocyte sub-population [neutrophils (NE), lymphocytes (LY), monocytes (MO)] is characterized by the mean (MN) and the standard deviation (SD) of 7 measurements called "cellular population data" (@CPD), corresponding to morphological analysis of the leukocytes. As severe forms of infections to SARS-CoV-2 are characterized by a functional activation of mononuclear cells, leading to a cytokine storm, we evaluated whether CPD variations are correlated to the inflammation state, oxygen requirement and lung damage and whether CPD analysis could be useful for a triage of patients with COVID-19 in the Emergency Department (ED) and could help to identify patients with a high risk of worsening.

Materials and method

The CPD of 825 consecutive patients with proven COVID-19 presenting to the ED were recorded and compared to classical biochemical parameters, the need for hospitalization in the ward or ICU, the need for oxygen, or lung injury on CT-scan.

Results

40 of the 42 CPD were significantly modified in COVID-19 patients in comparison to 245 controls. @MN-V-MO and @SD-V-MO were highly correlated with C-reactive protein, procalcitonin, ferritin and D-dimers. SD-UMALS-LY > 21.45 and > 23.92 identified, respectively, patients with critical lung injuries (>75%) and requiring tracheal intubation. @SD-V-MO > 25.03 and @SD-V-NE > 19.4 identified patients required immediate ICU admission, whereas a @MN-V-MO < 183 suggested that the patient could be immediately discharged. Using logistic regression, the combination of 8 CPD with platelet and basophil counts and the existence of diabetes or obesity could identify patients requiring ICU after a first stay in conventional wards (area under the curve = 0.843).

Conclusion

CPD analysis constitutes an easy and inexpensive tool for triage and prognosis of COVID-19 patients in the ED.

Usefulness of monocyte distribution width and presepsin for early assessment of disease severity in COVID-19 patients

Early predictors of severe coronavirus disease 2019 (COVID-19) would identify patients requiring intensive care. Recently, the monocyte distribution width (MDW) and presepsin level have been used for the early diagnosis of sepsis. Here, we assessed the utility of MDW and presepsin for the early assessment of COVID-19 severity. Eighty-seven inpatients with confirmed COVID-19 were enrolled and divided into 3 groups by the type of respiratory support: (1) mechanical ventilation or high-flow nasal cannula oxygen therapy (MVHF-OT), (2) conventional oxygen therapy, and (3) no oxygen therapy. We measured the complete blood count; MDW; erythrocyte sedimentation rate; and the levels of presepsin, C-reactive protein, procalcitonin, lactate dehydrogenase, ferritin, Krebs von den Lungen-6 (KL-6), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) neutralizing antibody. Thirteen (14.9%) patients on MVHF-OT exhibited a significantly higher mortality and a longer hospital stay than did the others. The MDW and presepsin levels were significantly elevated on admission, and correlated with COVID-19 severity (both P < .001). Notably, only the MDW correlated significantly with symptoms in the no oxygen therapy group (P < .012). In the first week after admission, the MDW fell and no longer differed among the groups. The KL-6 level did not differ by disease severity at any time. Neutralizing antibodies were detected in 74 patients (91.4%) and the level of neutralization correlated significantly with COVID-19 severity (P < .001). The MDW and presepsin are useful indicators for early assessment of disease severity in COVID-19 patients.

VCS parameters of neutrophils, monocytes and lymphocytes may indicate local bacterial infection in cancer patients who accepted cytotoxic chemotherapeutics

Bacterial infections increased greatly in cancer patients who accepted cytotoxic chemotherapeutics. VCS parameters of neutrophils were reported to be an indicator for acute bacterial infection accompanied by increased WBC counts. Here we explored the possibility of VCS parameters of neutrophils, monocytes and lymphocytes in indicating the local bacterial infection in cancer patients. A total of 310 cancer patients and 90 healthy controls were retrospectively analyzed, and 190 of them were diagnosed as acute local bacterial infection. The VCS parameters acquired from a Beckman Coulter LH750 haematology analyzer were investigated to determine which VCS parameters could indicate local bacterial infection in cancer patients with leucopenia caused by cytotoxic agents. VCS parameters of cancer patients were significantly affected by infection. For diagnosing bacterial infection of cancer patients, the best single indicator was mean monocyte light scatter (MMS) with a sensitivity of 95.12 % and a specificity of 58.82 % and the area under the curve (AUC) was 0.792. A combination of the following five parameters: mean neutrophil volume (MNV), MMS, mean lymphocyte conductivity (MLC), mean lymphocyte light scatter (MLS) and neutrophil volume distribution width (NDW) could provide a better index in diagnosing bacterial infection than any single parameter (sensitivity 75.8 %, specificity 64.72 %, AUC 0.763). Taking WBC counts into consideration, VCS parameters could better indicate bacterial infection for cancer patients with abnormal WBC level than that with normal WBC level. Aside from neutrophils, the VCS of monocytes and lymphocytes were also ideal indicators for bacterial infection. The combination of VCS parameters could increase the sensitivity, specificity and accuracy of diagnosis of cancer patients.

Automated screening for tuberculosis by multiparametric analysis of data obtained during routine complete blood count

INTRODUCTION

The main goal of this study was to develop a multiparametric cell population data (CPD) model that combines information from several morphologic parameters generated by DxH800, in addition to the traditional parameters regularly reported in the CBC-diff, and to test the performance of this model in screening the general population for primary tuberculosis (TB).

METHODS

A total of 3741 study cases were divided into two groups, test and validation set at cut-off value of 6000 WBCs/μL. We developed multiparametric model for primary TB screening (TB hemeprint), selected CPD, and calculated parameters which could discriminate primary TB from other non-TB diseases and normal control in test set. We applied it to the validation set, which was a set of completely different samples, to test its reproducibility if applied to a routine laboratory test.

RESULTS

After screening primary TB using TB hemeprint, sensitivity, specificity, PPV, and NPV were 85.4%, 89.6%, 31.1%, and 99.1%, respectively, in primary TB with lower than 6000 WBCs/μL of test set (test set-L). In primary TB with higher than 6000 WBCs/μL of test set (test set-H), those values were 83.1%, 85.6%, 29.7%, and 98.6%, respectively. There were only 0.4% (2/461) and 0.6% (2/326) of normal control samples included in test set-L and -H, respectively. Diagnostic efficiencies except sensitivity in each validation set were very comparable with those in each test set.

CONCLUSION

Tuberculosis hemeprint may allow us to screen primary TB with acceptable sensitivity and specificity using combination of TB-specific CPD and calculated parameters.

Leukocyte cell population data (volume conductivity scatter) in postprandial leukocyte activation

INTRODUCTION

Changes in leukocyte cell population data have been reported in various infectious diseases, but little is known in other inflammatory conditions such as the postprandial state. We investigated whether leukocyte cell population data change during postprandial leukocyte activation.

METHODS

Healthy volunteers underwent a standardized oral fat loading test (OFLT). Flowcytometric quantitation of leukocyte activation markers CD11b, CD66b, CD35, and CD36, together with leukocyte cell population data from LH750 hematology analyzers were measured fasting and at 4 and 8 h postprandially.

RESULTS

Twelve volunteers were included. Postprandial leukocyte activation was confirmed by increased expression of CD11b by monocytes (+11.7%) and neutrophils (+15.0%) and by increased expression of CD66b (+14.7%) and CD35 (+16.6%) by neutrophils at T = 4 h. The mean scatter from neutrophils, reflecting granularity, significantly decreased at T = 4 h (P < 0.05) and returned to baseline at T = 8 h (P-anova 0.048). The mean volume of monocytes increased significantly at T = 4 h (P < 0.001) and returned to baseline at T = 8 h (P-anova 0.0008). At T = 4 h, CD11b expression on neutrophils was associated with a reduction in mean scatter of neutrophils (Pearson's r: -0.677, P = 0.016).

CONCLUSION

Postprandial leukocyte activation is accompanied by temporary changes in leukocyte cell population data, similar to changes observed during various infections, but to a lesser extent.

Biological variations of leukocyte numerical and morphologic parameters determined by UniCel DxH 800 hematology analyzer

CONTEXT

The Coulter DxH 800 hematology analyzer can determine leukocyte numerical parameters (total leukocyte counts and differentials). It also measures intrinsic biophysical properties of these cells in their near-native state. These morphologic measurements are known as cell population data (CPD).

OBJECTIVE

To study, for the first time, the biological variations of morphologic parameters or CPD and reinvestigate numerical parameters using the newest Coulter hematology analyzer. Design.-Forty adult volunteers (21 women, 19 men) were included. All participants maintained their normal lifestyles. Blood samples were drawn in duplicate by a single experienced phlebotomist and analyzed within 2 hours using a single analyzer. Before each batch analysis, the instrument quality controls were performed using the same lots of reagents.

RESULTS

Within-subject (CV(I)) and between-subjects (CV(G)) biological variations for numerical parameters are smaller than previously reported. Cell population data have much smaller overall CV(I) and CV(G) compared to numerical parameters, suggesting that these parameters are less variable around the homeostatic set point intraindividually and interindividually. Index of individuality (ratio of CV(I)/CV(G)) for CPD was low. In addition, intraday and interday biological variations of all parameters are fairly constant.

CONCLUSIONS

These observations are clinically valuable. Data on CV(I) and analytical precision may be used to generate objective delta-check values for use in quality management. Comparing CV(I) and CV(G) on CPD may allow us to decide the utility of traditional population-based reference ranges. Documentation of CPD on biological variations is an essential prerequisite in the development of any new application clinically.

The lymph index: a potential hematological parameter for viral infection

OBJECTIVE

An LH750 hematology analyzer with VCS (volume, conductivity, and light scatter) technology can determine morphologic properties of peripheral leukocytes, known as cell population data (CPD). We have previously demonstrated that the lymphocyte CPD exhibit significant changes in acute hepatitis B virus infection. A simplified lymphocyte CPD, the lymph index, was proposed. We conducted the current study to further evaluate the clinical usefulness of the lymph index, and included patients with various viral infections, as well as those with acute bacterial infections.

METHODS

Peripheral blood was collected from 72 patients with viral infections, 46 patients with acute bacterial infections, and 204 controls. The lymphocyte CPD included the mean volume (LV) with its standard deviation (LV-SD) and the conductivity (LC). The lymph index was calculated as LV × LV-SD ÷ LC.

RESULTS

The lymph index was significantly increased in viral infections and only mildly increased in acute bacterial infections compared to controls. Using a lymph index cutoff value of ≥ 12.92, we achieved 91.67% sensitivity and 97.2% specificity for diagnosing viral infection.

CONCLUSIONS

The findings may be clinically useful since these morphological parameters are readily obtained by hematology analyzer during automated leukocyte differentials. They are quantitative, objective, and fast. The lymph index could be a potential hematological parameter for viral infection.