White blood cell count and eosinopenia as valuable tools for the diagnosis of bacterial infections in the ED

Diagnostic model for spontaneous bacterial peritonitis in cirrhotic patients with ascites: a multicenter cohort study

INTRODUCTION

Spontaneous bacterial peritonitis (SBP) is a potentially life-threatening complication of cirrhotic ascites. Early diagnosis and treatment of SBP are essential to improve the survival rates and prognosis of patients. We aimed to identify the predictors of SBP to establish a new noninvasive early diagnostic tool.

METHODS

We screened 1618 patients who underwent paracentesis due to cirrhotic ascites between January 2017 and December 2018 in three hospitals. We evaluated the symptomatic, clinical, and laboratory parameters to identify the predictors of SBP. The primary diagnostic model was displayed as a nomogram.

RESULTS

The model included abdominal pain, diarrhea, white blood cell count, neutrophil percentage, procalcitonin, C-reactive protein, lactate dehydrogenase, glucose, and Model for End-stage Liver Disease score. The model's diagnostic performance was good, with an AUC of 0.84 [95% confidence interval (CI), 0.81-0.87] in the training cohort. In the validation cohort, the diagnostic ability was also good, with AUCs of 0.87 (95% CI, 0.83-0.91) and 0.90 (95% CI, 0.87-0.94) for inner and outer validation queues, respectively. Moreover, the decision curve analysis confirmed the clinical utility of the nomogram model. In addition, we developed a Microsoft Excel calculation model to allow convenient adoption of the model in clinical practice.

CONCLUSION

We developed good performing diagnostic models for SBP.

Comparative analysis of lysophospholipid metabolism profiles and clinical characteristics in patients with high vs. low C-reactive protein levels in acute exacerbations of chronic obstructive pulmonary disease

BACKGROUND

The precise role of lysophospholipids (LysoPLs) in the pathogenesis of acute exacerbations of Chronic Obstructive Pulmonary Disease (AECOPD) remains unclear. In this study, we sought to elucidate the differences in serum LysoPL metabolite profiles and their correlation with clinical features between patients with low versus high CRP levels.

METHODS

A total of 58 patients with AECOPD were enrolled in the study. Patients were classified into two groups: low CRP group (CRP < 20 mg/L, n = 34) and high CRP group (CRP ≥ 20 mg/L, n = 24). Clinical data were collected, and the LysoPL metabolite profiles were analyzed using Liquid Chromatography-Mass Spectrometry (LC-MS) and identified by matching with the LipidBlast library.

RESULTS

Nineteen differential LysoPLs were initially identified through Student's t-test (p < 0.05 and VIP > 1). Subsequently, four LysoPLs, LPC(16:0), LPE(18:2), LPC(22:0), and LPC(24:0), were identified by FDR adjustment (adjusted p < 0.05). These four lysoPLs had a significant negative correlation with CRP. Integrative analysis revealed that LPC (16:0) and LPC (22:0) correlated with less hypercapnic respiratory failure and ICU admission.

CONCLUSION

AECOPD patients with high CRP levels demonstrated a distinctive LysoPL metabolism profile, with LPC (16:0), LPE(18:2), LPC(22:0), and LPC(24:0) being the most significantly altered lipid molecules. These alterations were associated with poorer clinical outcomes.

Clinical evaluation of a fully electronic microfluidic white blood cell analyzer

The White Blood Cell (WBC) count is one of the key parameters signaling the health of the immune system. Abnormal WBC counts often signal a systemic insult to the body such as an underlying infection or an adverse side effect to medication. Typically, the blood collected is sent to a central lab for testing, and results come back within hours, which is often inconvenient and may delay time-sensitive diagnosis or treatment. Here, we present the CytoTracker, a fully electronic, microfluidic based instant WBC analyzer with the potential to be used at point-of-care. The CytoTracker is a lightweight, portable, affordable platform capable of quantifying WBCs within minutes using only 50 μl of blood (approximately one drop of blood). In this study, we clinically evaluated the accuracy and performance of CytoTracker in measuring WBC and granulocyte counts. A total of 210 adult patients were recruited in the study. We validated the CytoTracker against a standard benchtop analyzer (Horiba Point of Care Hematology Analyzer, ABX Micros 60). Linear dynamic ranges of 2.5 k/μl- 35 k/μl and 0.6 k/μl- 26 k/μl were achieved for total WBC count and granulocyte count with correlation coefficients of 0.97 and 0.98. In addition, we verified CytoTracker's capability of identifying abnormal blood counts with above 90% sensitivity and specificity. The promising results of this clinical validation study demonstrate the potential for the use of the CytoTracker as a reliable and accurate point-of-care WBC analyzer.

Admission blood eosinophil count, inpatient death and death at 1 year in exacerbating patients with COPD

BACKGROUND

Blood eosinophil counts have been studied in patients with stable chronic obstructive pulmonary disease (COPD) and are a useful biomarker to guide inhaled corticosteroid use. Less is known about eosinophil counts during severe exacerbation.

METHODS

In this retrospective study, 2645 patients admitted consecutively with COPD exacerbation across six UK hospitals were included in the study, and the clinical diagnosis was confirmed by a respiratory specialist. The relationship between admission eosinophil count, inpatient death and 1-year death was assessed. In a backward elimination, Poisson regression analysis using the log-link function with robust estimates, patients' markers of acute illness and stable-state characteristics were assessed in terms of their association with eosinopenia.

RESULTS

1369 of 2645 (52%) patients had eosinopenia at admission. Those with eosinopenia had a 2.5-fold increased risk of inpatient death compared with those without eosinopenia (12.1% vs 4.9%, RR=2.50, 95% CI 1.88 to 3.31, p<0.001). The same mortality risk with eosinopenia was seen among the subgroup with pneumonic exacerbation (n=788, 21.3% vs 8.5%, RR=2.5, 95% CI 1.67 to 2.24, p<0.001). In a regression analysis, eosinopenia was significantly associated with: older age and male sex; a higher pulse rate, temperature, neutrophil count, urea and C reactive protein level; a higher proportion of patients with chest X-ray consolidation and a reduced Glasgow Coma Score; and lower systolic and diastolic blood pressure measurements and lower oxygen saturation, albumin, platelet and previous admission counts.

DISCUSSION

During severe COPD exacerbation, eosinopenia is common and associated with inpatient death and several markers of acute illness. Clinicians should be cautious about using eosinophil results obtained during severe exacerbation to guide treatment decisions regarding inhaled corticosteroid use.

Systemic inflammatory markers differentiate between orbital cellulitis and non-specific orbital inflammation

PURPOSE

Bacterial orbital cellulitis (OC) and diffuse non-specific orbital inflammation (DNSOI) may be challenging to differentiate clinically. This study investigates the utility of systemic inflammatory markers, namely white cell count (WCC) and C-reactive protein (CRP), in differentiating between OC and DNSOI.

METHODS

A single-centre retrospective study of patients diagnosed with OC or DNSOI, between 2003 to 2021, who had WCC and/or CRP obtained at presentation. The mean levels of these factors and the proportion of positivity were compared between OC and DNSOI. A receiver operating characteristic (ROC) analysis was conducted to calculate the specificity and sensitivity of WCC or CRP in each group.

RESULTS

49 patients were included in this study. The mean age was 56 ± 20 years, and 21 patients were females. 26 (53.1%) patients had OC, and 23 (46.9%) patients had DNSOI. Mean WCC for OC and DNSOI were 14.5 × 10³/μL and 9.27 × 10³/μL, respectively (P = 0.001). Mean CRP for OC and DNSOI were 104.4 mg/L and 10.0 mg/L, respectively (P < 0.001). The optimal CRP cut-off value of 20.2 mg/L demonstrated 90.9% sensitivity and 90.5% specificity (AUC = 0.946, P < 0.001) for differentiating between OC and DNSOI. CRP was more predictive of OC than WCC (P = 0.017). 7/26 (26.9%) OC patients with fever also had an elevated CRP, while 1/23 (4.3%) of DNSOI with fever had a normal CRP.

CONCLUSIONS

An elevated WCC is suggestive of OC. However, a normal WCC can neither exclude nor differentiate between OC and DNSOI. CRP may be a more accurate predictor of OC compared to WCC.

Parameters of the complete blood count predict in hospital mortality

INTRODUCTION

Mortality rates are used to evaluate the quality of hospital care after adjusting for disease severity and, commonly also, for age, comorbidity, and laboratory data with only few parameters of the complete blood count (CBC).

OBJECTIVE

To identify the parameters of the CBC that predict independently in-hospital mortality of acutely admitted patients.

POPULATION

All patients were admitted to internal medicine, cardiology, and intensive care departments at the Laniado Hospital in Israel in 2018 and 2019.

VARIABLES

Independent variables were patients' age, sex, and parameters of the CBC. The outcome variable was in-hospital mortality.

ANALYSIS

Logistic regression. In 2018, we identified the variables that were associated with in-hospital mortality and validated this association in the 2019 cohort.

RESULTS

In the validation cohort, a model consisting of nine parameters that are commonly available in modern analyzers had a c-statistics (area under the receiver operator curve) of 0.86 and a 10%-90% risk gradient of 0%-21.4%. After including the proportions of large unstained cells, hypochromic, and macrocytic red cells, the c-statistic increased to 0.89, and the risk gradient to 0.1%-29.5%.

CONCLUSION

The commonly available parameters of the CBC predict in-hospital mortality. Addition of the proportions of hypochromic red cells, macrocytic red cells, and large unstained cells may improve the predictive value of the CBC.

Characteristics of peripheral white blood cells in COVID-19 patients revealed by a retrospective cohort study

Background

Peripheral hematological changes in severe COVID-19 patients may reflect the immune response during SARS-CoV-2 infection. Characteristics of peripheral white blood cells as early signals were needed to be investigated for clarifying its associations with the fatal outcomes in COVID-19 patients.

Methods

A retrospective cohort study was performed and the hospitalized COVID-19 patients were recruited in wards of Sino-French New City Branch of Tongji Hospital in Wuhan, Hubei province, China. Characteristics of peripheral white blood cells in survivors and non-survivors were analyzed. Comparison among patients with different level of eosinophils was performed.

Results

Of 198 patients included in this study, 185 were discharged and 13 died. Levels of eosinophils, lymphocytes and basophils in non-survivors were significantly lower than those in survivors. Death rate in low eosinophils group was higher and no patient died in normal eosinophils group (16.7% vs 0, P < 0.001). The proportion of patients in low eosinophils group who used glucocorticoids was higher than in normal eosinophils group, but glucocorticoids usage was not an indicator for death in subgroup analysis in low eosinophils patients. Moreover, positive correlation was found between the counts of lymphocytes and eosinophils in patients with glucocorticoids use but not in patients without the treatment.

Conclusions

Hematological changes differed between survivors and non-survivors with COVID-19. Lymphopenia and eosinopenia could be predictors for poor prognosis of COVID-19 patients. Initial counts of eosinophils may guide us in usage of glucocorticoids for COVID-19 treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06899-7.

COVID-19 coagulopathies: Human blood proteins mimic SARS-CoV-2 virus, vaccine proteins and bacterial co-infections inducing autoimmunity: Combinations of bacteria and SARS-CoV-2 synergize to induce autoantibodies targeting cardiolipin, cardiolipin-binding proteins, platelet factor 4, prothrombin, and coagulation factors

Severe COVID-19 is often accompanied by coagulopathies such as thrombocytopenia and abnormal clotting. Rarely, such complications follow SARS-CoV-2 vaccination. The cause of these coagulopathies is unknown. It is hypothesized that coagulopathies accompanying SARS-CoV-2 infections and vaccinations result from bacterial co-infections that synergize with virus-induced autoimmunity due to antigenic mimicry of blood proteins by both bacterial and viral antigens. Coagulopathies occur mainly in severe COVID-19 characterized by bacterial co-infections with Streptococci, Staphylococci, Klebsiella, Escherichia coli, and Acinetobacter baumannii. These bacteria express unusually large numbers of antigens mimicking human blood antigens, as do both SARS-CoV-2 and adenoviruses. Bacteria mimic cardiolipin, prothrombin, albumin, and platelet factor 4 (PF4). SARS-CoV-2 mimics complement factors, Rh antigens, platelet phosphodiesterases, Factors IX and X, von Willebrand Factor (VWF), and VWF protease ADAMTS13. Adenoviruses mimic prothrombin and platelet factor 4. Bacterial prophylaxis, avoidance of vaccinating bacterially infected individuals, and antigen deletion for vaccines may reduce coagulopathy risk. Also see the video abstract here: https://youtu.be/zWDOsghrPg8.

The Value of a Complete Blood Count (CBC) for Sepsis Diagnosis and Prognosis

Sepsis represents an important global health burden due to its high mortality and morbidity. The rapid detection of sepsis is crucial in order to prevent adverse outcomes and reduce mortality. However, the diagnosis of sepsis is still challenging and many efforts have been made to identify reliable biomarkers. Unfortunately, many investigated biomarkers have several limitations that do not support their introduction in clinical practice, such as moderate diagnostic and prognostic accuracy, long turn-around time, and high-costs. Complete blood count represents instead a precious test that provides a wealth of information on individual health status. It can guide clinicians to early-identify patients at high risk of developing sepsis and to predict adverse outcomes. It has several advantages, being cheap, easy-to-perform, and available in all wards, from the emergency department to the intensive care unit. Noteworthy, it represents a first-level test and an alteration of its parameters must always be considered within the clinical context, and the eventual suspect of sepsis must be confirmed by more specific investigations. In this review, we describe the usefulness of basic and new complete blood count parameters as diagnostic and prognostic biomarkers of sepsis.

A cross-sectional study on evaluation of complete blood count-associated parameters for the diagnosis of acute appendicitis

BACKGROUND AND AIMS

Acute appendicitis is one of the common causes of abdominal surgeries, however, the rate of negative appendectomy is as high as 20% as the diagnosis of appendicitis is challenging. The study aimed to evaluate complete blood count (CBC)-associated parameters among positive and negative appendectomy patients and determine their diagnostic importance.

METHODS

In this cross-sectional study, patients who suspected of acute appendicitis were included. Preoperative blood samples taken from these patients for a complete blood count. Following parameters evaluated from their CBC: white blood cell (WBC), platelet (PLT), mean platelet volume (MPV), neutrophils-to-lymphocytes ratio, platelets-to-lymphocytes ratio, red cell distribution width (RDW), and platelet distribution width (PDW). These parameters analyzed for the positive and negative appendectomy patients using statistical analysis.

RESULTS

Of 200 patients included in the study, 30 patients (15%) underwent negative appendectomy. The mean neutrophils, WBC, red blood cells, neutrophils-to-lymphocytes, and platelets-to-lymphocytes ratio was significantly high among positive appendectomy patients, (P < .05), whereas MPV to platelet ratio was significantly less in this group. The highest diagnostic power for the diagnosis of appendicitis was of neutrophils-to-lymphocytes ratio with the sensitivity of 83.5% and the specificity of 90%.

CONCLUSION

The findings of our study indicate that neutrophils-to-lymphocytes ratio alone is not sufficient for preoperative diagnosis of acute appendicitis and other CBC-related parameters did not have good sensitivity and specificity. Further studies are therefore required in this area.

Reduction/elimination of blood eosinophils in severe asthma: should there be a safety consideration?

INTRODUCTION

Eosinophils play a central role in the inflammation of asthma and are the target of new biologic treatments for patients with severe asthma. Biologics targeting the IL-5 pathway have been shown to reduce asthma exacerbations, improve lung function, reduce oral corticosteroid use, and improve quality of life, accompanied by reduced or even eliminated blood eosinophils. Eosinophils have been associated with host protection and tumor growth, raising potential concerns about the consequences of these long-term therapies that reduce or eliminate them.

AREAS COVERED

In this review, we explore the current safety profile of biologics regarding the impact they may have on blood eosinophils, trying to answer the question about any safety consideration.

EXPERT OPINION

Eosinophils have been associated with host protection and tumor growth, raising potential concerns about the consequences of long-term therapies that reduce or eliminate these blood cells.

Admission glycemic gap in the assessment of patients with intracerebral hemorrhage

BACKGROUND

Intracerebral hemorrhage (ICH) is the most common type of hemorrhagic stroke. Glycemic gap, determined by the difference between glucose and the HbA1c-derived average glucose, predicts poor outcomes in various clinical settings. Our main objective was to evaluate association of some admission factors and outcomes in relation to admission glycemic gap (AGG) in patients with ICH.

METHODS

We retrospectively analyzed 506 adult patients with ICH between 2014 and 2019. AGG was defined as A1c-derived average glucose (28.7×HbA1c-46.7) subtracted from admission glucose. Admission factors and hospital outcomes indicative of poor outcome (i.e. death, gastrostomy tube, tracheostomy, and discharge status) were compared between patients with elevated (greater than 80 mg/dL) vs. non-elevated (less than or equal-to 80 mg/dL) AGG. Pearson chi-square test was used for independence, and multivariate analysis was used for association. SPSS and excel were used for all data analysis.

RESULTS

We found that 67 of 506 (13%) ICH patients had elevated AGG with a mean of 137.3 mg/dL compared to 439 (87%) non-elevated AGG with a mean of 12.6 mg/dL. While mean and standard deviation values for age, weight,and body mass index were comparable between groups, the elevated AGG group had significantly higher admission glucose (286.1 ± 84.3 vs. 140.1 ± 42.5, p < 0.001), higher lactic acid (3.26 ± 2.04 mmol/L vs. 1.99 ± 1.33 mmol/L, p < 0.001), lower Glasgow Coma Scale (GCS) scores (7.70 ± 4.28 vs. 11.24 ± 4.14, p < 0.001), and higher ICH score (median 3, IQR 2-4 vs. median 1, IQR 0-3, p < 0.001). Higher AGG was associated with an increased likelihood of mechanical ventilation, and in-hospital mortality (74.6% vs. 38.3% and 47.8% vs. 15.0% respectively, p < 0.001). Placements of tracheostomy and gastrostomy were similar between the two groups (13.4% vs. 11.8%, p = 0.69% and 1.5% and 4.6%, p = 0.34 respectively). The higher AGG group had a more common poor discharge outcome to either long-term acute care, skilled nursing facility, and/or hospice (65.7% vs. 42.6%, p < 0.001). Hospital cost and length of hospitalization did not differ significantly. Although AGG was not an independent predictor of poor outcome, multivariate analysis showed it was significantly associated with poor outcome while admission glucose was not (p < 0.001 vs. p = 0.167).

CONCLUSION

Elevated AGG was associated with worse GCS and ICH scores on admission, as well as need for mechanical ventilation, in hospital mortality and poor discharge status. Elevated AGG has value in prediction of outcome, but existing understanding is limited.

A simple index predicting 30-day readmissions in acutely hospitalized patients

BACKGROUND

There are various models attempting to predict 30-day readmissions of acutely admitted internal medicine patients. However, it is uncertain how to create a parsimonious index that has equivalent predictive ability and can be extrapolated to other settings.

METHODS

We developed a regression equation to predict 30-day readmissions from all acute hospitalizations in internal medicine departments in a regional hospital in 2015-2016 and validated the model in 2019. The independent (predictor) variables were age, past hospitalizations, admission laboratory test results, length of stay in hospital and discharge diagnoses. We compared the predictive value of a logistic regression model and index that included discharge diagnoses and admission laboratory test results with one that included only age, past hospitalizations, and hospital length of stay.

RESULTS

Readmission rates were associated with age, time since last hospitalization, number of previous hospitalizations, and length of stay, as well as with a diagnosis of chronic obstructive lung disease and congestive heart failure and several laboratory data. Logistic regressions of the independent variables for 30-day readmission rates were similar in 2015-2016 and 2019. An index was derived from number of previous admissions to hospitals, time since last admission, age, and length of stay. In 2019, for every unit of the index, the odds of readmission increased by 1.33 (95% CI- 1.30-1.37), and ranged from 2.1% to 37.1%. Addition of discharge diagnoses and laboratory variables did not significantly improve the risk differentiation of the index. The c-statistic for the final parsimonious model was 0.704.

CONCLUSIONS

An index derived from the number of previous hospital admissions, days since last admission, age, and length of stay in days differentiated between the risks of readmission within 30 days without the need for discharge diagnosis and laboratory variables.

Eosinophils and COVID-19: diagnosis, prognosis, and vaccination strategies

The unprecedented impact of the coronavirus disease 2019 (COVID-19) pandemic has resulted in global challenges to our health-care systems and our economic security. As such, there has been significant research into all aspects of the disease, including diagnostic biomarkers, associated risk factors, and strategies that might be used for its treatment and prevention. Toward this end, eosinopenia has been identified as one of many factors that might facilitate the diagnosis and prognosis of severe COVID-19. However, this finding is neither definitive nor pathognomonic for COVID-19. While eosinophil-associated conditions have been misdiagnosed as COVID-19 and others are among its reported complications, patients with pre-existing eosinophil-associated disorders (e.g., asthma, eosinophilic gastrointestinal disorders) do not appear to be at increased risk for severe disease; interestingly, several recent studies suggest that a diagnosis of asthma may be associated with some degree of protection. Finally, although vaccine-associated aberrant inflammatory responses, including eosinophil accumulation in the respiratory tract, were observed in preclinical immunization studies targeting the related SARS-CoV and MERS-CoV pathogens, no similar complications have been reported clinically in response to the widespread dissemination of either of the two encapsulated mRNA-based vaccines for COVID-19.

Silent existence of eosinopenia in sepsis: a systematic review and meta-analysis

BACKGROUND

Sepsis is a life-threatening and time-critical medical emergency; therefore, the early diagnosis of sepsis is essential to timely treatment and favorable outcomes for patients susceptible to sepsis. Eosinopenia has been identified as a potential biomarker of sepsis in the past decade. However, its clinical application progress is slow and its recognition is low. Recent studies have again focused on the potential association between Eosinopenia and severe infections. This study analyzed the efficacy of Eosinopenia as a biomarker for diagnosis of sepsis and its correlation with pathophysiology of sepsis.

METHOD

The protocol for this meta-analysis is available in PROSPERO (CRD42020197664). We searched PubMed, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials CENTRAL databases to identify studies that met the inclusion criteria. Two authors performed data extraction independently. The pooled outcomes were calculated by TP (true positive), FP (false positive), FN (false negative), TN (true negative) by using bivariate meta-analysis model in STATA 14.0 software. Meanwhile, possible mechanisms of sepsis induced Eosinopenia was also analyzed.

RESULTS

Seven studies were included in the present study with a total number of 3842 subjects. The incidence of Eosinopenia based on the enrolled studies varied from 23.2 to 92.7%. For diagnosis of sepsis, the pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio and diagnostic odds ratio of Eosinopenia were 0.66 (95%CI [0.53-0.77]), 0.68 (95%CI [0.56-0.79]), 2.09 (95%CI [1.44-3.02]), 0.49 (95%CI [0.34-0.71]) and 4.23 (95%CI [2.15-8.31]), respectively. The area under the summary receiver operator characteristic curve (SROC) was 0.73 (95%CI [0.68-0.76]). Meta-regression analysis revealed that no single parameter accounted for the heterogeneity of pooled outcomes. For each subgroup of different eosinopenia cutoff values (50, 40, ≤25, 100), the sensitivity was 0.61, 0.79, 0.57, 0.54, and the specificity was 0.61, 0.75, 0.83, 0.51, respectively.

CONCLUSIONS

Our findings suggested that Eosinopenia has a high incidence in sepsis but has no superiority in comparison with conventional biomarkers for diagnosis of sepsis. However, eosinopenia can still be used in clinical diagnosis for sepsis as a simple, convenient, fast and inexpensive biomarker. Therefore, further large clinical trials are still needed to re-evaluate eosinopenia as a biomarker of sepsis.

The role of eosinophils in sepsis and acute respiratory distress syndrome: a scoping review

PURPOSE

Septic shock and acute respiratory distress syndrome (ARDS) are characterized by a dysregulated immune host response that may respond to steroid therapy. Eosinophils contribute to type 2 inflammation that often responds to steroid therapy; their role in immune dysregulation and outcomes in sepsis and ARDS is unclear.

SOURCE

A systematic search of Cochrane Library, MEDLINE, and EMBASE was performed from inception to 9 September 2020. The search comprised the following terms: eosinophils, sepsis, septic shock, and ARDS. Two reviewers independently screened abstracts and texts and extracted data on disease severity and clinical outcomes.

PRINCIPAL FINDINGS

Thirty-nine studies were identified: 30 evaluated serum eosinophil count in sepsis, one evaluated eosinophil activity in sepsis, three assessed bronchoalveolar lavage (BAL) eosinophil count in ARDS, four assessed eosinophil activity in ARDS, and one assessed peripheral eosinophil count in ARDS. Eleven studies showed an association between eosinopenia and sepsis, and eight studies found persistent eosinopenia at > 48 hr of intensive care unit admission to predict mortality and readmission in septic patients. Three studies found BAL eosinophil count to be low in ARDS, although one found that levels rose in late-phase ARDS. Three studies found eosinophil activity markers in BAL to be high in ARDS and correlate with ARDS severity.

CONCLUSION

Persistent peripheral eosinopenia is a marker of bacterial sepsis and is independently associated with poor outcomes. Bronchoalveolar lavage eosinophil counts are low in early-phase ARDS, but increase in late-phase ARDS, while elevated markers of eosinophil activity correlate with ARDS severity. Further studies understanding the mechanisms leading to eosinopenia in sepsis and increased eosinophil activity in ARDS are needed.

A simple index predicting mortality in acutely hospitalized patients

BACKGROUND

Mortality rates used to evaluate and improve the quality of hospital care are adjusted for comorbidity and disease severity. Comorbidity, measured by International Classification of Diseases codes, do not reflect the severity of the medical condition, that requires clinical assessments not available in electronic databases, and/or laboratory data with clinically relevant ranges to permit extrapolation from one setting to the next.

AIM

To propose a simple index predicting mortality in acutely hospitalized patients.

DESIGN

Retrospective cohort study with internal and external validation.

METHODS

The study populations were all acutely admitted patients in 2015-16, and in January 2019-November 2019 to internal medicine, cardiology and intensive care departments at the Laniado Hospital in Israel, and in 2002-19, at St. James Hospital, Ireland. Predictor variables were age and admission laboratory tests. The outcome variable was in-hospital mortality. Using logistic regression of the data in the 2015-16 Israeli cohort, we derived an index that included age groups and significant laboratory data.

RESULTS

In the Israeli 2015-16 cohort, the index predicted mortality rates from 0.2% to 32.0% with a c-statistic (area under the receiver operator characteristic curve) of 0.86. In the Israeli 2019 validation cohort, the index predicted mortality rates from 0.3% to 38.9% with a c-statistic of 0.87. An abbreviated index performed similarly in the Irish 2002-19 cohort.

CONCLUSIONS

Hospital mortality can be predicted by age and selected admission laboratory data without acquiring information from the patient's medical records. This permits an inexpensive comparison of performance of hospital departments.

Innate Receptor Activation Patterns Involving TLR and NLR Synergisms in COVID-19, ALI/ARDS and Sepsis Cytokine Storms: A Review and Model Making Novel Predictions and Therapeutic Suggestions

Severe COVID-19 is characterized by a “cytokine storm”, the mechanism of which is not yet understood. I propose that cytokine storms result from synergistic interactions among Toll-like receptors (TLR) and nucleotide-binding oligomerization domain-like receptors (NLR) due to combined infections of SARS-CoV-2 with other microbes, mainly bacterial and fungal. This proposition is based on eight linked types of evidence and their logical connections. (1) Severe cases of COVID-19 differ from healthy controls and mild COVID-19 patients in exhibiting increased TLR4, TLR7, TLR9 and NLRP3 activity. (2) SARS-CoV-2 and related coronaviruses activate TLR3, TLR7, RIG1 and NLRP3. (3) SARS-CoV-2 cannot, therefore, account for the innate receptor activation pattern (IRAP) found in severe COVID-19 patients. (4) Severe COVID-19 also differs from its mild form in being characterized by bacterial and fungal infections. (5) Respiratory bacterial and fungal infections activate TLR2, TLR4, TLR9 and NLRP3. (6) A combination of SARS-CoV-2 with bacterial/fungal coinfections accounts for the IRAP found in severe COVID-19 and why it differs from mild cases. (7) Notably, TLR7 (viral) and TLR4 (bacterial/fungal) synergize, TLR9 and TLR4 (both bacterial/fungal) synergize and TLR2 and TLR4 (both bacterial/fungal) synergize with NLRP3 (viral and bacterial). (8) Thus, a SARS-CoV-2-bacterium/fungus coinfection produces synergistic innate activation, resulting in the hyperinflammation characteristic of a cytokine storm. Unique clinical, experimental and therapeutic predictions (such as why melatonin is effective in treating COVID-19) are discussed, and broader implications are outlined for understanding why other syndromes such as acute lung injury, acute respiratory distress syndrome and sepsis display varied cytokine storm symptoms.

Do Blood Eosinophils Predict in-Hospital Mortality or Severity of Disease in SARS-CoV-2 Infection? A Retrospective Multicenter Study

Introduction: Healthcare systems worldwide have been battling the ongoing COVID-19 pandemic. Eosinophils are multifunctional leukocytes implicated in the pathogenesis of several inflammatory processes including viral infections. We focus our study on the prognostic value of eosinopenia as a marker of disease severity and mortality in COVID-19 patients. Methods: Between 1 March and 30 April 2020, we conducted a multicenter and retrospective study on a cohort of COVID-19 patients (moderate or severe disease) who were hospitalized after presenting to the emergency department (ED). We led our study in six major hospitals of northeast France, one of the outbreak’s epicenters in Europe. Results: We have collected data from 1035 patients, with a confirmed diagnosis of COVID-19. More than three quarters of them (76.2%) presented a moderate form of the disease, while the remaining quarter (23.8%) presented a severe form requiring admission to the intensive care unit (ICU). Mean circulating eosinophils rate, at admission, varied according to disease severity (p < 0.001), yet it did not differ between survivors and non-survivors (p = 0.306). Extreme eosinopenia (=0/mm³) was predictive of severity (aOR = 1.77, p = 0.009); however, it was not predictive of mortality (aOR = 0.892, p = 0.696). The areas under the Receiver operating characteristics (ROC) curve were, respectively, 58.5% (CI95%: 55.3–61.7%) and 51.4% (CI95%: 46.8–56.1%) for the ability of circulating eosinophil rates to predict disease severity and mortality. Conclusion: Eosinopenia is very common and often profound in cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Eosinopenia was not a useful predictor of mortality; however, undetectable eosinophils (=0/mm³) were predictive of disease severity during the initial ED management.

Inflammatory Markers and Duration of Symptoms Have a Close Connection With Diagnosis and Staging of Acute Appendicitis in Children

Background: For children with acute appendicitis (AA), a clear diagnosis is a challenge. The purpose of this study is to explore whether inflammatory markers in the blood combined with symptom duration are helpful in the diagnosis of acute appendicitis and in predicting the severity of acute appendicitis. Methods: All the selected patients underwent appendectomy between November 10, 2011 and November 15, 2019, in whom preoperative WBCC, CRP, and NE% had been measured in a short time. All patients were divided into two groups: uncomplicated AA and complicated AA, postoperatively. Results: For our standards, 813 patients were selected, 442 of them had complicated AA. The mean [standard deviation (SD)] age for the uncomplicated AA group was 9.78 ± 2.02 years and for the complicated AA group was 9.69 ± 2.16 years (P = 0.55). Elevated WBCC, CRP, and NE% had a higher relatively sensitivity in complicated AA than uncomplicated AA especially when WBCC, CRP, and NE% were at normal levels, which had a sensitivity of 100% in uncomplicated AA, but this only applied to nine patients. CRP values were significantly different in three time groups, whether uncomplicated or complicated AA. Conclusion: The combination of WBCC, CRP, and NE% values is very sensitive for the diagnosis of acute appendicitis, and when we predict complicated AA using the CRP value, we also need to consider the time of symptom onset.

Predicting bacteraemia in maternity patients using full blood count parameters: A supervised machine learning algorithm approach

INTRODUCTION

Bacteraemia in pregnancy and the post-partum period can lead to maternal and newborn morbidly. The purpose of this study was to use machine learning tools to identify if bacteraemia in pregnant or post-partum women could be predicted by full blood count (FBC) parameters other than the white cell count.

METHODS

The study was performed on 129 women with a positive blood culture (BC) for a clinically significant organism, who had a FBC taken at the same time. They were matched with controls who had a negative BC taken at the same time as a FBC. The data were split in to a training (70%) and test (30%) data set. Machine learning techniques such as recursive partitioning and classification and regression trees were used.

RESULTS

A neutrophil/lymphocyte ratio (NLR) of >20 was found to be the most clinically relevant and interpretable construct of the FBC result to predict bacteraemia. The diagnostic accuracy of NLR >20 to predict bacteraemia was then examined. Thirty-six of the 129 bacteraemia patients had a NLR >20, while only 223 of the 3830 controls had a NLR >20. This gave a sensitivity of 27.9% (95% CI 20.3-36.4), specificity of 94.1% (93.3-94.8), positive predictive value of 13.9% (10.6-17.9) and a negative predictive value (NPV) of 97.4% (97.2-97.7) when the prevalence of bacteraemia was 3%.

CONCLUSION

The NLR should be considered for use in routine clinical practice when assessing the FBC result in patients with suspected bacteraemia during pregnancy or in the post-partum period.

Clinical Characteristics and Prognosis of Adult Orbital Cellulitis in a Tertiary General Hospital

Purpose

Adult orbital cellulitis (OC) occurs relatively rarely, and comprehensive studies that retrospectively evaluate OC are lacking. Here, we aimed to examine the clinical characteristics and prognosis of OC in a tertiary general hospital.

Methods

Between October 2010 and May 2019, patients presenting with clinical symptoms of OC in a tertiary general hospital were analyzed in this retrospective study. Twenty-six cases were identified for a detailed review. In these cases, 16 males and 10 females were diagnosed with orbital cellulitis by clinical characteristics and multimodal examinations. We divided patients into three groups: (1) patients secondary to rhinosinusitis, (2) patients secondary to endogenous infection(s) without endophthalmitis, and (3) patients secondary to endophthalmitis. For each group, age, gender, eye type, combined systemic diseases, clinical presentation, leukocyte count, blood culture, diagnostic imaging, therapeutic methods, length of stay, time of postoperation, and patient prognosis were analyzed in detail.

Results

There were no significant differences regarding age, gender, preoperative leukocyte count, exophthalmia, blood culture, treatment, or visual changes within the three groups (P < 0.05). There were significant differences, however, in postoperative leukocyte count and ophthalmoplegia between the three groups (P < 0.05). The preoperative and postoperative logarithms of the minimum resolution angle scored by the best-corrected visual acuity (LogMAR BCVA) of group 3 were statistically significant compared to group 1 and group 2 (P < 0.05).

Conclusion

We confirmed that the prognosis of OC patients combined with systemic diseases was poor. Patients with OC secondary to endophthalmitis infrequently experience ophthalmoplegia; however, these patients still have poor visual outcomes. Patients cultured positive for Klebsiella pneumoniae infection may not be associated with liver abscess. The level of leukocytes may indicate the condition of the disease.

Eosinopenia in COVID-19 Patients: A Retrospective Analysis

Objectives: The aim of this study was to assess the diagnostic role of eosinophils count in COVID-19 patients. Methods: Retrospective analysis of patients admitted to our hospital with suspicion of COVID-19. Demographic, clinical and laboratory data were collected on admission. Eosinopenia was defined as eosinophils < 100 cells/mm³. The outcomes of this study were the association between eosinophils count on admission and positive real-time reverse transcription polymerase chain reaction (rRT-PCR) test and with suggestive chest computerized tomography (CT) of COVID-19 pneumonia. Results: A total of 174 patients was studied. Of those, 54% had positive rRT-PCR for SARS-CoV-2. A chest CT-scan was performed in 145 patients; 71% showed suggestive findings of COVID-19. Eosinophils on admission had a high predictive accuracy for positive rRT-PCR and suggestive chest CT-scan (area under the receiver operating characteristic-ROC curve, 0.84 (95% CIs 0.78-0.90) and 0.84 (95% CIs 0.77-0.91), respectively). Eosinopenia and high LDH were independent predictors of positive rRT-PCR, whereas eosinopenia, high body mass index and hypertension were predictors for suggestive CT-scan findings. Conclusions: Eosinopenia on admission could predict positive rRT-PCR test or suggestive chest CT-scan for COVID-19. This laboratory finding could help to identify patients at high-risk of COVID-19 in the setting where gold standard diagnostic methods are not available.

Eosinopenia as predictor of infection in patients admitted to an internal medicine ward: a cross-sectional study

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Background:

The identification of infection in an internal medicine ward is crucial but not always straightforward. Eosinopenia has been proposed as a marker of infection, but specific cutoffs for prediction are not established yet. We aim to assess whether there is difference in eosinophil count between infected and noninfected patients and, if so, the best cutoffs to differentiate them.

Methods:

Cross-sectional, observational study with analysis of all patients admitted to an Internal Medicine Department during 2 consecutive months. Clinical, laboratory and imaging data were analyzed. Infection at hospital admission was defined in the presence of either a microbiological isolation or suggestive clinical, laboratory, and/or imaging findings. Use of antibiotics in the 8 days before hospital admission, presence of immunosuppression, hematologic neoplasms, parasite, or fungal infections were exclusion criteria. In case of multiple hospital admissions, only the first admission was considered.

Sensitivity and specificity values for eosinophils, leukocytes, neutrophils, and C-reactive protein were determined by receiver operating characteristic curve. Statistical analysis was performed with IBM SPSS Statistics® v25 and MedCalc Statistical Software® v19.2.3.

Results:

A total of 323 hospitalization episodes were evaluated, each corresponding to a different patient. One hundred fifteen patients were excluded. A total of 208 patients were included, 62.0% (n = 129) of them infected at admission. Ten patients had multiple infections.

Infected patients had fewer eosinophils than uninfected patients (15.8 ± 42 vs 71.1 ± 159 cell/mm³; P < .001). An eosinophil count at admission ≤69 cell/mm³ had a sensitivity of 89.1% and specificity of 54.4% (area under the curve 0.752; 95% confidence interval 0.682–0.822) for the presence of infection. Eosinophil count of >77 cells/mm³ had a negative likelihood ratio of 0.16.

Conclusions:

Eosinophil count was significantly lower in infected than in uninfected patients. The cutoff 69 cells/mm³ was the most accurate in predicting infection. Eosinophil count >77 cells/mm³ was a good predictor of absence of infection.

Possible Cross-Reactivity between SARS-CoV-2 Proteins, CRM197 and Proteins in Pneumococcal Vaccines May Protect Against Symptomatic SARS-CoV-2 Disease and Death

Various studies indicate that vaccination, especially with pneumococcal vaccines, protects against symptomatic cases of SARS-CoV-2 infection and death. This paper explores the possibility that pneumococcal vaccines in particular, but perhaps other vaccines as well, contain antigens that might be cross-reactive with SARS-CoV-2 antigens. Comparison of the glycosylation structures of SARS-CoV-2 with the polysaccharide structures of pneumococcal vaccines yielded no obvious similarities. However, while pneumococcal vaccines are primarily composed of capsular polysaccharides, some are conjugated to cross-reacting material CRM197, a modified diphtheria toxin, and all contain about three percent protein contaminants, including the pneumococcal surface proteins PsaA, PspA and probably PspC. All of these proteins have very high degrees of similarity, using very stringent criteria, with several SARS-CoV-2 proteins including the spike protein, membrane protein and replicase 1a. CRM197 is also present in Haemophilus influenzae type b (Hib) and meningitis vaccines. Equivalent similarities were found at lower rates, or were completely absent, among the proteins in diphtheria, tetanus, pertussis, measles, mumps, rubella, and poliovirus vaccines. Notably, PspA and PspC are highly antigenic and new pneumococcal vaccines based on them are currently in human clinical trials so that their effectiveness against SARS-CoV-2 disease is easily testable.

Eosinopenia in Patients With Typhoid Fever: A Case-Control Study

Background and objectives Salmonella typhi is involved in one of the most prevalent infectious diseases of South East Asia, typhoid fever, but diagnostic tests cannot be performed regularly in developing countries. The objective of the study is to determine the association of eosinopenia with culture or serology-proven typhoid fever in patients, to determine the association of leukopenia with culture or serology-proven typhoid fever in patients and to determine independent predictors of eosinopenia. Methods This case-control study, done at Fauji Foundation Hospital, Pakistan, included patients with symptoms suggestive of typhoid fever, culture, or serology positive for typhoid fever and excluded patients who had been previously diagnosed with malaria and dengue hemorrhagic fever. After flagging cultures and serology, the records were viewed for leukocyte counts. Data, including age, gender, and clinical symptoms, were also recorded for analysis. Results Out of 200 participants, 59 participants with diagnosed typhoid fever had eosinopenia. There were 29 participants who had been diagnosed with typhoid fever via culture or serology and had leukopenia. Eosinopenia and leukopenia were more likely to be present in patients with a diagnosis of typhoid (OR: 9.60, 20.00). The independent predictors for eosinopenia were DOT enzyme immunoassay (DOT EIA) positive for Salmonella typhi, culture positive for Salmonella typhi and leukopenia (p<0.05). Conclusion The presence of eosinopenia and features or serology suggestive of typhoid would most likely be associated with cultures being positive and, therefore, might provide an efficient means to begin treatment.

Age and Location in Severity of COVID-19 Pathology: Do Lactoferrin and Pneumococcal Vaccination Explain Low Infant Mortality and Regional Differences?

Two conundrums puzzle COVID-19 investigators: 1) morbidity and mortality is rare among infants and young children and 2) rates of morbidity and mortality exhibit large variances across nations, locales, and even within cities. It is found that the higher the rate of pneumococcal vaccination in a nation (or city) the lower the COVID-19 morbidity and mortality. Vaccination rates with Bacillus Calmette-Guerin, poliovirus, and other vaccines do not correlate with COVID-19 risks, nor do COVID-19 case or death rates correlate with number of people in the population with diabetes, obesity, or adults over 65. Infant protection may be due to maternal antibodies and antiviral proteins in milk such as lactoferrin that are known to protect against coronavirus infections. Subsequent protection might then be conferred (and correlate with) rates of Haemophilus influenzae type B (Hib) (universal in infants) and pneumococcal vaccination, the latter varying widely by geography among infants, at-risk adults, and the elderly. Also see the video abstract here https://youtu.be/GODBYRbPL00.

Distribution characteristics of serum β2-microglobulin between viral and bacterial lower respiratory tract infections: a retrospective study

BACKGROUND

Lower respiratory tract infection (LRTI) is one of the leading cause of death in children under 5 years old around the world between 1980 and 2016. Distinguishing between viral and bacterial infection is challenging when children suffered from LRTI in the absence of pathogen detection. The aim of our study is to analyze the difference of serum β2-microglobulin (β2-MG) between viral LRTI and bacterial LRTI in children.

METHODS

This retrospective study included children with LRTI caused by a single pathogen from Yancheng Third People's Hospital, Yancheng, China, between January 1, 2016 and December 31, 2019. Participants were divided into the younger group (1 year old ≤ age < 3 years old) and the older group (3 years old ≤ age < 5 years old) for subgroup analysis.

RESULTS

A total of 475 children with LRTI caused by common respiratory pathogens were identified. In the younger group as well as the older group, the serum level of β2-MG in respiratory syncytial virus, influenza A virus and influenza B virus groups were significantly increased compared to that in the Mycoplasma pneumoniae group. Compared with Streptococcus pneumoniae infection group, the serum β2-MG level of respiratory syncytial virus, influenza A virus and influenza B virus groups were significantly higher in children between 1 and 3 years old.

CONCLUSIONS

The serum β2-MG may distinguish viral infection from bacterial infection in children with LRTI.

Age-dependent changes of total and differential white blood cell counts in children

BACKGROUND

Total and differential white blood cell counts are important for the diagnostic evaluation of suspected diseases. To facilitate the interpretation of total and differential white blood cell counts in pediatric patients, the present study investigated age-dependent changes in total and differential white blood cell counts in healthy reference children.

METHODS

Data were obtained from the Pediatric Reference Intervals in China study (PRINCE), which aims to establish and verify pediatric reference intervals for Chinese children based on a nationwide multicenter cross-sectional study from January 2017 to December 2018. Quantile curves were calculated using the generalized additive models for location, shape, and scale method. The 2.5th, 50th, and 97.5th quantile curves were calculated for both total and differential white blood counts. Percents of stacked area charts were used to demonstrate the proportions of differential white blood cells. All statistical analyses were performed using R software.

RESULTS

Both 50th and 97.5th quantiles of total white blood cell count and monocyte count were highest at birth, then rapidly decreased in the first 6 months of life; relatively slow reduction continued until 2 years of age. The lymphocyte count was low during infancy and increased to its highest level at 6 months of age; it then exhibited moderate and continuous reduction until approximately 9 years of age. The pattern of neutrophil count changed with age in a manner opposite to that of lymphocyte count. Besides, there were two inter-sections of lymphocyte count and neutrophil count during infancy and at approximately 5 years of age, based on locally weighted regression (LOESS) analysis. There were no apparent age-related changes in eosinophil or basophil counts.

CONCLUSION

These data regarding age-related changes in total and differential white blood cell counts can be used to assess the health of pediatric patients and guide clinical decisions.

Eosinophil responses during COVID-19 infections and coronavirus vaccination

Eosinophils are circulating and tissue-resident leukocytes that have potent proinflammatory effects in a number of diseases. Recently, eosinophils have been shown to have various other functions, including immunoregulation and antiviral activity. Eosinophil levels vary dramatically in a number of clinical settings, especially following eosinophil-targeted therapy, which is now available to selectively deplete these cells. There are key coronavirus disease 2019 (COVID-19)-related questions concerning eosinophils whose answers affect recommended prevention and care. First, do patients with eosinophilia-associated diseases have an altered course of COVID-19? Second, do patients with eosinopenia (now intentionally induced by biological drugs) have unique COVID-19 susceptibility and/or disease course? This is a particularly relevant question because eosinopenia is associated with acute respiratory deterioration during infection with the severe acute respiratory syndrome coronavirus 2, the causative agent of COVID-19. Third, do eosinophils contribute to the lung pathology induced during COVID-19 and will they contribute to immunopotentiation potentially associated with emerging COVID-19 vaccines? Herein, we address these timely questions and project considerations during the emerging COVID-19 pandemic.

Characteristics and prognostic factors of disease severity in patients with COVID-19: The Beijing experience

COVID-19 has become one of the worst infectious disease outbreaks of recent times, with over 2.1 million cases and 120,000 deaths so far. Our study investigated the demographic, clinical, laboratory and imaging features of 63 patients with COVID-19 in Beijing. Patients were classified into four groups, mild, moderate, severe and critically ill. The mean age of our patients was 47 years of age (range 3-85) and there was a slight male predominance (58.7%). Thirty percent of our patients had severe or critically ill disease, but only 20% of severe and 33% of critically ill patients had been to Wuhan. Fever was the most common presentation (84.1%), but cough was present in only slightly over half of the patients. We found that lymphocyte and eosinophils count were significantly decreased in patients with severe disease (p = 0.001 and p = 0.000, respectively). Eosinopenia was a feature of higher levels of severity. Peripheral CD4⁺, CD8⁺ T lymphocytes, and B lymphocytes were significantly decreased in severe and critically ill patients, but there was only a non-statistically significant downward trend in NK cell numbers with severity. Of note is that liver function tests including AST, ALT, GGT and LDH were elevated, and albumin was decreased. The inflammatory markers CRP, ESR and ferritin were elevated in patients with severe disease or worse. IL-6 levels were also higher, indicating that the presence of a hyperimmune inflammatory state portends higher morbidity and mortality. In a binary logistic regression model, C-reactive protein level (OR 1.073, [CI, 1.013-1.136]; p = 0.017), CD8 T lymphocyte counts (OR 0.989, [CI, 0.979-1.000]; p = 0.043), and D-dimer (OR 5.313, [CI, 0.325-86.816]; p = 0.241) were independent predictors of disease severity.