Relationship between blood eosinophil levels and COVID-19 mortality

The Association of Blood Eosinophils and Neutrophils Expressing Eosinophilic Surface Markers with the Severity and Outcome of COVID-19

(1) Background: The implication of type 2 (T2) inflammatory response in COVID-19 remains controversial. This study aimed to evaluate the association of eosinophils, neutrophils expressing eosinophilic surface markers and T2 cytokines with the severity and outcome of COVID-19. (2) Methods: Patients who were admitted to hospital due to COVID-19 from 18 December 2022 to 31 January 2023 were enrolled. Peripheral blood WBC and differentials, T2 cellular markers (subsets of eosinophils and neutrophils expressing eosinophilic surface markers) and cytokines at admission were measured and compared between subjects with different disease severities and outcomes. (3) Results: Ten mild-to-moderate and 22 severe-to-very severe cases were enrolled for analysis. Of these patients, seven died of severe-to-very severe disease. The severe-to-very severe patients showed a higher number of neutrophils, but lower numbers of eosinophils, lymphocytes cells and neutrophils expressing eosinophilic surface markers. Similarly, deceased cases were also characterized by increased neutrophils, but decreased eosinophils and neutrophils expressing eosinophilic surface markers. The levels of T2 cytokines failed to demonstrate a significant correlation with the severity or outcome of COVID-19. (4) Conclusions: Eosinophils and neutrophils expressing eosinophilic surface markers were associated with milder disease and better outcomes of COVID-19, suggesting that a T2 inflammatory response may confer a potential protective effect against the disease.

Eosinophils as modulators of host defense during parasitic, fungal, bacterial, and viral infections

Eosinophils, traditionally associated as central innate effector cells with type 2 immunity during allergic and helminth parasitic diseases, have recently been revealed to have important roles in tissue homeostasis as well as host defense in a broader variety of infectious diseases. In a dedicated session at the 2023 biennial conference of the International Eosinophil Society titled "Eosinophils in Host Defense," the multifaceted roles eosinophils play against diverse pathogens, ranging from parasites to fungi, bacteria, and viruses, were presented. In this review, the session speakers offer a comprehensive summary of recent discoveries across pathogen classes, positioning eosinophils as pivotal leukocytes in both host defense and pathology. By unraveling the intricacies of eosinophil engagement in host resistance, this exploration may provide valuable insights not only to understand specific underpinnings of eosinophil functions related to each class of pathogens but also to develop novel therapeutics effective against a broad spectrum of infectious diseases.

Serum beta2-microglobulin and peripheral blood eosinophils for the assessment of severity and prognosis with omicron variant COVID-19 infection

Background

The Omicron variant's high transmissibility has made it the most widespread novel coronavirus variant. Elevated serum β2-MG levels from viral infections and EOS' role in viral clearance have garnered attention. However, their predictive value for Omicron's severity and prognosis needs further exploration.

Methods

This retrospective study included 424 patients with confirmed COVID-19 Omicron variant admitted to the Second Hospital of Jilin University in Changchun, China, of whom 128 experienced in-hospital mortality. Patients were divided into high and low groups according to β2-MG and EOS levels; the relationship between disease severity and patient prognosis was analyzed.

Results

Our findings showed that severe-to-critical Omicron patients had higher β2-MG levels than mild-normal patients. Conversely, EOS levels were higher in mild-moderate cases. Both β2-MG and EOS levels normalized when Omicron patients tested negative for nucleic acid. Deceased Omicron patients had significantly lower pre-mortem EOS levels. Elevated β2-MG and lower EOS levels correlated with reduced overall survival. Multivariate COX regression analysis indicated that elevated β2-MG was an independent adverse prognostic factor for Omicron patients.

Conclusion

High serum β2-MG levels and low eosinophil levels upon admission correlate with omicron variant severity and prognosis. β2-MG is an independent risk factor for poor outcomes in omicron patients.

Blood Eosinophils Matter in Post-COVID-19 Pneumonia

BACKGROUND

Even after the development of vaccines, SARS-CoV-2 continues to cause severe pneumonia all over the world. Consequently, in order to improve the management of patients and optimize the use of resources, predictors of disease severity and lung complications after COVID-19 pneumonia are urgently needed. Blood cell count is an easily available and reproducible biomarker. With this study, we aimed to explore the role of eosinophils in predicting disease behavior and pulmonary sequelae at first follow-up with computed tomography (CT).

METHODS

we evaluated blood cell count and other inflammatory markers, both at baseline and during hospitalization, in a large population of hospitalized COVID-19 patients.

RESULTS

327 patients were finally enrolled, 214 were classified as low-intensity medical care (LIMC) and 113 as high-intensity medical care. Eosinophils were higher at discharge in the HIMC group [0.1 (0-0.72) vs. 0.05 (0-0.34) × 109/L; p < 0.0001]. Moreover, in the multivariable analysis, age ≥ 62 years (OR 1.76 (1.05-2.8) p = 0.03) and Δ eosinophils ≥ 0.05 (OR 1.75 (1.05-2.9) p = 0.03) were two independent predictors of residual lung abnormalities in the whole patient population at first follow-up.

CONCLUSIONS

an eosinophil increase during hospitalization could be a potential predictor of pulmonary sequelae in surviving patients after COVID-19 pneumonia.

Frailty as a Predictor of COVID-19 Mortality in the South Indian Population: An Observational Study

Background Frailty is a clinical syndrome characterized by diminished strength, endurance, and physiological function that significantly increases vulnerability to adverse health outcomes, including infections. In the context of COVID-19, frailty has emerged as a critical risk factor for severe disease, complications, and mortality, particularly in older adults. The severity and fatality rates among the geriatric group were notably high, as the virus's pathogenesis, marked by prolonged inflammation, contributed to increased morbidity and mortality in this age group. The study was conducted to explore the role of frailty in influencing mortality among the elderly affected by COVID-19. Objective The objective of this study was to identify the association between frailty and mortality in COVID-19-affected elderly patients.  Methods We conducted a prospective observational study among elderly patients who tested positive for COVID-19 and received treatment in a tertiary care hospital. Data were collected from 250 patients from March 2021 to December 2021. Lab parameters, the necessity for mechanical ventilation, the need for oxygen use, and the number of days of hospital stay were recorded. The Clinical Frailty Score (CFS) was used to evaluate frailty. The chi-square test with Fisher's exact test was used to assess the association between frailty and mortality in the data set. Multivariate binary logistic regression was employed to identify the most significant predictors of mortality. Results Among the 250 patients, 159 (63.6%) survived and were discharged, while 91 (36.4%) succumbed to the illness. Fifty-eight patients were not identified as frail, and there were no deaths in the group. On the contrary, among the 192 COVID-positive patients who were identified as frail, 91 (47.4%) patients died, and 101 (52.6%) patients were alive. This depicted the association between frailty and mortality in COVID-19 geriatric patients. While assessing comorbidities, malignancy (53.3%, p-value = 0.009) and chronic kidney disease (CKD) (43.3%) had a significant association with mortality. Symptoms like fever (43.6%), dyspnea (68.6%), myalgia (20%), and altered sensorium (84%) showed a strong correlation with mortality (p<0.001). Frailty was a significant predictor of mortality, with 47.4% of frail patients not surviving (p<0.001). Biochemical markers including leukocytosis (64.8%), neutrophilia (65.3%), eosinopenia (66.9%), anemia (57.8%), hypoalbuminemia (63.5%), hypoproteinemia (70.1%), elevated alanine aminotransferase (ALT) (66%), aspartate aminotransferase (AST) (65.2%), alkaline phosphatase (ALP) (67.5%), elevated creatinine (68.9%), hypernatremia (100%), hyperkalemia (80%), and elevated D-dimer (44.7%) were all significantly linked to mortality. Additionally, patients requiring oxygen (65%), ventilation (96.8%), or bilevel positive airway pressure (BiPAP) (77.8%) had higher mortality rates. A shorter length of hospital stay was also associated with increased mortality (24%). Conclusion Frailty, combined with certain comorbidities such as cancer and CKD, along with various clinical and biochemical markers, played a significant role in predicting mortality among geriatric COVID-19 patients. Incorporating frailty assessments into routine evaluations for elderly COVID-19 survivors could be beneficial. Early detection and focused management of these high-risk factors are essential for improving outcomes in frail patients within tertiary care settings.

Chemerin Levels in COVID-19 Are More Affected by Underlying Diseases than by the Virus Infection Itself

BACKGROUND/OBJECTIVES

Chemerin is an adipokine involved in inflammatory and metabolic diseases, and its circulating levels have been associated with inflammatory parameters in various patient cohorts. Severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) infection, which causes COVID-19, triggers inflammatory pathways. However, the association between serum chemerin levels and COVID-19 disease severity and outcomes has not been definitively established.

METHODS

In this study, serum chemerin levels were analyzed in 64 patients with moderate COVID-19 and 60 patients with severe disease.

RESULTS

The results showed that serum chemerin levels were comparable between these two groups and slightly higher than in healthy controls. Notably, COVID-19 patients with hypertension exhibited elevated serum chemerin levels, while those with liver cirrhosis had lower levels. When patients with these comorbidities were excluded from the analyses, serum chemerin levels in COVID-19 patients were similar to those in healthy controls. Positive correlations were observed between serum chemerin levels and markers such as alkaline phosphatase, C-reactive protein, eosinophils, and lymphocytes in the entire cohort, as well as in the subgroup excluding patients with hypertension and cirrhosis. Additionally, urinary chemerin levels were comparable between COVID-19 patients and controls, and neither hypertension nor dialysis significantly affected urinary chemerin levels. Both survivors and non-survivors had similar serum and urinary chemerin levels.

CONCLUSIONS

In conclusion, this study suggests that comorbidities such as arterial hypertension and liver cirrhosis do have a more significant impact on serum chemerin levels than SARS-CoV-2 infection itself.

Differentiating COVID-19 and influenza in children: hemogram parameters as diagnostic tools

Introduction

It is not always possible to differentiate between influenza and COVID-19 based on symptoms alone. This is a topic of significant importance as it aims to determine whether there are specific hematological parameters that can be used to distinguish between influenza and COVID-19 in children.

Methodology

Two hundred thirty-one children between the ages of 1 month and 18 years who presented to the children's outpatient clinic between June 2021 and June 2022 with similar symptoms and were tested with an influenza test and a COVID-19 PCR test were included in the study. Of the patients included in the study, 130 tested positive for COVID-19 and 101 positive for influenza. The patients were evaluated for hematological parameters.

Results

Age, eosinophils and monocyte factors were shown to be statistically significantly effective in COVID-19. The risk of COVID-19 increased 1,484-fold with age, 10,708-fold with increasing eosinophil count, and 1,591-fold with increasing monocyte count. The performance of the monocyte count and eosinophil count was assessed by receiver operating characteristic curve (ROC) analysis. According to the performed ROC analysis, the area under the curve (AUC) value was observed to be 0.990 for monocytes. According to the cutoff point >1.50, the sensitivity value was determined as 98.4% and the specificity value as 97.0%. AUC significance for eosinophils was found to be 0.989. According to the cutoff point >0.02, the sensitivity value was determined as 99.2% and the specificity value as 93.1%.

Conclusion

In the diagnosis of COVID-19, the eosinophil count and monocyte count are easily accessible, inexpensive, and important parameters in terms of differential diagnosis and can help in the differentiation of COVID-19 from influenza during seasonal outbreaks of the latter. Developing parameters for clinicians to use in diagnosing COVID-19 and influenza can facilitate their work in practice.

Immune Response Dynamics and Biomarkers in COVID-19 Patients

BACKGROUND

The immune response dynamics in COVID-19 patients remain a subject of intense investigation due to their implications for disease severity and treatment outcomes. We examined changes in leukocyte levels, eosinophil activity, and cytokine profiles in patients hospitalized with COVID-19.

METHODS

Serum samples were collected within the first 10 days of hospitalization/confirmed infection and analyzed for eosinophil granule proteins (EGP) and cytokines. Information from medical records including comorbidities, clinical symptoms, medications, and complete blood counts were collected at the time of admission, during hospitalization and at follow up approximately 3 months later.

RESULTS

Serum levels of eotaxin, type 1 and type 2 cytokines, and alarmin cytokines were elevated in COVID-19 patients, highlighting the heightened immune response (p < 0.05). However, COVID-19 patients exhibited lower levels of eosinophils and eosinophil degranulation products compared to hospitalized controls (p < 0.05). Leukocyte counts increased consistently from admission to follow-up, indicative of recovery.

CONCLUSION

Attenuated eosinophil activity alongside elevated chemokine and cytokine levels during active infection, highlights the complex interplay of immune mediators in the pathogenesis COVID-19 and underscores the need for further investigation into immune biomarkers and treatment strategies.

Bronchial Asthma and COVID-19: Etiology, Pathological Triggers, and Therapeutic Considerations

Bronchial asthma (BA) continues to be a difficult disease to diagnose. Various factors have been described in the development of BA, but to date, there is no clear evidence for the etiology of this chronic disease. The emergence of COVID-19 has contributed to the pandemic course of asthma and immunologic features. However, there are no unambiguous data on asthma on the background and after COVID-19. There is correlation between various trigger factors that provoke the development of bronchial asthma. It is now obvious that the SARS-CoV-2 virus is one of the provoking factors. COVID-19 has affected the course of asthma. Currently, there is no clear understanding of whether asthma progresses during or after COVID-19 infection. According to the results of some studies, a significant difference was identified between the development of asthma in people after COVID-19. Mild asthma and moderate asthma do not increase the severity of COVID-19 infection. Nevertheless, oral steroid treatment and hospitalization for severe BA were associated with higher COVID-19 severity. The influence of SARS-CoV-2 infection is one of the protective factors. It causes the development of severe bronchial asthma. The accumulated experience with omalizumab in patients with severe asthma during COVID-19, who received omalizumab during the pandemic, has strongly suggested that continued treatment with omalizumab is safe and may help prevent the severe course of COVID-19. Targeted therapy for asthma with the use of omalizumab may also help to reduce severe asthma associated with COVID-19. However, further studies are needed to prove the effect of omalizumab. Data analysis should persist, based on the results of the course of asthma after COVID-19 with varying degrees of severity.

Eosinopenia as a prognostic factor of mortality for COVID-19 in end-stage kidney disease patients

Background

The unique role of eosinophil in coronavirus disease 2019 (COVID-19) patients has been shown in several studies, but its role in end-stage kidney disease (ESKD) patients who contracted COVID-19 is less reported. This study investigated eosinopenia's predictive value as a mortality marker in ESKD patients with COVID-19.

Methods

It is a retrospective study of ESKD patients who contracted COVID-19 between May 2020 and October 2021 in West Nusa Tenggara General Hospital, Indonesia. Comparative analysis was carried out between the death dan survival group. Logistic regression analysis was done to investigate the role of eosinopenia on the outcome after controlling other significant variables.

Results

The analyses included one hundred fifteen confirmed COVID-19 in ESKD patients. The average age was 50, 53% of patients were males, 41% were newly diagnosed with ESKD, and the mortality rate was 25.2%. This study's prevalence of eosinopenia, high neutrophil-to-lymphocyte ratio (NLR), and high C-reactive protein (CRP) in the nonsurvivors was 51.4%, 39.3%, and 30.8%, respectively. Diastolic blood pressure <90 mmHg (P=0.004), respiratory rate >22 x/minutes (P=0.011), oxygen saturation <93% (P=0.008), NLR >6 (p<0.001), eosinophil count <0.01 x103/uL (p<0.001), CRP >20 mg/L (P=0.047), and isolation hemodialysis (HD) therapy (p<0.001) were independently associated with mortality of COVID-19 in ESKD patients. However, on multivariate logistic regression analysis, eosinopenia (P=0.019) and HD (P=0.001) were risk factors that remained significant prognostic mortality factors.

Conclusion

Eosinopenia was common in ESKD patients with COVID-19, particularly in the death group. Eosinopenia at admission and HD during hospitalization were risk factors for COVID-19 mortality in ESKD patients.

Adhatoda vasica and Tinospora cordifolia extracts ameliorate clinical and molecular markers in mild COVID-19 patients: a randomized open-label three-armed study

BACKGROUND

SARS-CoV-2 infections caused mild-to-moderate illness. However, a sizable portion of infected people experience a rapid progression of hyper-inflammatory and hypoxic respiratory illness that necessitates an effective and safer remedy to combat COVID-19.

METHODS

A total of 150 COVID-19-positive patients with no to mild symptoms, between the age groups 19-65 years were enrolled in this randomized, open-labeled three-armed clinical trial. Among them, 136 patients completed the study with RT-PCR negative reports. The patients received herbal drugs orally (Group A (Adhatoda vasica; AV; 500 mg; n = 50); Group B (Tinospora cordifolia; TC; 500 mg; n = 43), and Group C (AV + TC; 250 mg each; n = 43)) for 14 days. Clinical symptoms, vital parameters, and viral clearance were taken as primary outcomes, and biochemical, hematological parameters, cytokines, and biomarkers were evaluated at three time points as secondary outcomes.

RESULTS

We found that the mean viral clearance time was 13.92 days (95% confidence interval [CI] 12.85-14.99) in Group A, 13.44 days (95% confidence interval [CI] 12.14-14.74) in Group B, and 11.86 days (95% confidence interval [CI] 10.62-13.11) days in Group C. Over a period of 14 days, the mean temperature in Groups A, and B significantly decreased linearly. In Group A, during the trial period, eosinophils, and PT/INR increased significantly, while monocytes, SGOT, globulin, serum ferritin, and HIF-1α, a marker of hypoxia reduced significantly. On the other hand, in Group B hsCRP decreased at mid-treatment. Eosinophil levels increased in Group C during the treatment, while MCP-3 levels were significantly reduced.

CONCLUSIONS

All the patients of the three-armed interventions recovered from COVID-19 and none of them reported any adverse effects from the drugs. Group C patients (AV + TC) resulted in a quicker viral clearance as compared to the other two groups. We provide the first clinical report of AV herbal extract acting as a modifier of HIF-1α in COVID-19 patients along with a reduction in levels of ferritin, VEGF, and PT/INR as the markers of hypoxia, inflammation, and thrombosis highlighting the potential use in progression stages, whereas the TC group showed immunomodulatory effects. Trial registration Clinical Trials Database -India (ICMR-NIMS), CTRI/2020/09/028043. Registered 24th September 2020, https://www.ctri.nic.in/Clinicaltrials/pdf_generate.php?trialid=47443&EncHid=&modid=&compid=%27,%2747443det%27.

The role of first trimester eosinophil count and eosinophil-based complete blood cell indices in the predictiction of preeclampsia: A case-control study

INTRODUCTION

The importance of eosinophils in the pathogenesis of preeclampsia is an question of interest and there are recent studies in the literature indicating significantly lower eosinophil count values in pregnant women with preeclampsia. The present study aims to evaluate the utility of first-trimester eosinophil count and eosinophil-based complete blood cell count indices in the prediction of preeclampsia.

METHODS

Pregnant women diagnosed with preeclampsia (n = 281) were retrospectively compared with a control group (n = 307). The utility of first trimester eosinophil count, neutrophil to eosinophil ratio (NER) (neutrophil/eosinophil), leukocyte to eosinophil ratio (LER) (leukocyte/eosinophil), eosinophil to monocyte ratio (EMR) (eosinophil/monocyte) and, eosinophil to lymphocyte ratio (ELR) (eosinophil/lymphocyte) in the prediction of preeclampsia were evaluated.

RESULTS

Optimal cut-off values for eosinophil count, NER, LER, EMR and, ELR in predicting preeclampsia were 0.07 (AUC: 0.62, 58.7% sensitivity, 56.4% specificity), 90.9 (AUC: 0.65, 61.1% sensitivity, 59.4% specificity), 125.7 (AUC: 0.64, 61.4% sensitivity, 58.4% specificity), 0.15 (AUC: 0.63, 60.1% sensitivity, 59.6% specificity) and, 0.03 (AUC: 0.62, 60.9% sensitivity, 57% specificity), respectively. Mentioned values in predicting early-onset preeclampsia were 0.07 (AUC: 0.64, 60.5% sensitivity, 50.8% specificity), 102.1 (AUC: 0.64, 62.4% sensitivity, 58.8% specificity), 140.2 (AUC: 0.65, 63.5% sensitivity, 59.1% soecificity), 0.14 (AUC: 0.66, 66.3% sensitivity, 59.2% specificity), and, 0.03 (AUC: 0.63, 60.5% sensitivity, 57.4% specificity), respectively. The optimal cut-off value for EMR in the prediction of preeclampsia with severe features was 0.16 (AUC: 0.56, 56.9% sensitivity, 53.2% specificity).

DISCUSSION

Eosinophil-based complete blood count indices may be used to predict early-onset preeclampsia with relatively low sensitivity and specificity.

Predicting COVID-19 prognosis in hospitalized patients based on early status

IMPORTANCE

COVID-19 remains the fourth leading cause of death in the United States. Predicting COVID-19 patient prognosis is essential to help efficiently allocate resources, including ventilators and intensive care unit beds, particularly when hospital systems are strained. Our PLABAC and PRABLE models are unique because they accurately assess a COVID-19 patient's risk of death from only age and five commonly ordered laboratory tests. This simple design is important because it allows these models to be used by clinicians to rapidly assess a patient's risk of decompensation and serve as a real-time aid when discussing difficult, life-altering decisions for patients. Our models have also shown generalizability to external populations across the United States. In short, these models are practical, efficient tools to assess and communicate COVID-19 prognosis.

The Effects and Outcomes of the COVID-19 Pandemic on Pregnant Women in Kuwait

OBJECTIVES

This retrospective study reports the effects of COVID-19 among hospitalized pregnant women infected with COVID-19 and compares them to a control group.

METHODS

A multi-center retrospective cohort study, in which data of pregnant women with COVID-19, admitted to five different hospitals in Kuwait, were collected. Two groups were included, the first group were women with COVID-19 who were admitted between March 22, 2020 until December 31, December 2020. The second (control) group included pregnant women without COVID-19, who were admitted between March 1, 2019 and March 21, 2020. Data were collected using a standardized data collection survey, entered using Excel Software and analyzed using Analysis of Variance (ANOVA).

RESULTS

We compared 764 patients, with confirmed COVID-19 with 765 uninfected control subjects. The majority of pregnant women were diagnosed with COVID-19 infection during the third trimester. Tachycardia was the most frequent sign at admission and dry cough and fever were the most common presenting symptoms. ICU admission and respiratory failure were significantly higher in the COVID-19 group. Cesarean section (CS) rate was higher in the COVID-19 group, with obstetric and maternal complications being the most common indications in comparison to fetal indications in the control group.

CONCLUSIONS

This study was conducted to identify the effects of COVID-19 in pregnancy. Most patients were asymptomatic. The rate of normal vaginal delivery was higher in the control group. The main indications for Cesarean section in the COVID-19 group were obstetrical and maternal complications compared to fetal complications in the control group.  .

Eosinophils as potential biomarkers in respiratory viral infections

Eosinophils are bone marrow-derived granulocytes that, under homeostatic conditions, account for as much as 1-3% of peripheral blood leukocytes. During inflammation, eosinophils can rapidly expand and infiltrate inflamed tissues, guided by cytokines and alarmins (such as IL-33), adhesion molecules and chemokines. Eosinophils play a prominent role in allergic asthma and parasitic infections. Nonetheless, they participate in the immune response against respiratory viruses such as respiratory syncytial virus and influenza. Notably, respiratory viruses are associated with asthma exacerbation. Eosinophils release several molecules endowed with antiviral activity, including cationic proteins, RNases and reactive oxygen and nitrogen species. On the other hand, eosinophils release several cytokines involved in homeostasis maintenance and Th2-related inflammation. In the context of SARS-CoV-2 infection, emerging evidence indicates that eosinophils can represent possible blood-based biomarkers for diagnosis, prognosis, and severity prediction of disease. In particular, eosinopenia seems to be an indicator of severity among patients with COVID-19, whereas an increased eosinophil count is associated with a better prognosis, including a lower incidence of complications and mortality. In the present review, we provide an overview of the role and plasticity of eosinophils focusing on various respiratory viral infections and in the context of viral and allergic disease comorbidities. We will discuss the potential utility of eosinophils as prognostic/predictive immune biomarkers in emerging respiratory viral diseases, particularly COVID-19. Finally, we will revisit some of the relevant methods and tools that have contributed to the advances in the dissection of various eosinophil subsets in different pathological settings for future biomarker definition.

The association of preexisting severe asthma with COVID-19 outcomes

PURPOSE OF REVIEW

Three years after the emergence of coronavirus disease 2019 (COVID-19), many studies have examined the association between asthma and COVID-related morbidity and mortality, with most showing that asthma does not increase risk. However, the U.S. Centers for Disease Control (CDC) currently suggests that patients with severe asthma may, nonetheless, be particularly vulnerable to COVID-19-related morbidity.

RECENT FINDINGS

With respect to poor COVID-19 outcomes, our search yielded nine studies that quantified associations with severe asthma, seven that considered use of monoclonal antibodies (mAB), and 14 that considered inhaled corticosteroids (ICS) use. mAb and ICS use have been used as measures of severe asthma in several studies. Severe asthma was significantly associated with poor COVID-19 outcomes. The results for mAb and ICS were mixed.

SUMMARY

An increased risk of poor COVID-19 outcomes in patients with severe asthma is possible. However, these studies remain sparse and suffer from several methodological limitations that hinder their interpretation. Additional evidence is needed to provide clear, cogent guidance for health agencies seeking to inform patients with asthma about potential risks due to COVID-19.

Investigating the role of obstructive pulmonary diseases and eosinophil count at admission on all-cause mortality in SARS-CoV-2 patients : A single center registry-based retrospective cohort study

INTRODUCTION

The impact of asthma and chronic obstructive pulmonary disease (COPD) in the setting of severe acute respiratory syndrome coronavirus 2 (SARS-CoV‑2) infection is not clearly defined. Blood eosinophil count is a standard diagnostic test which, according to the previously published literature, might have a potential prognostic role on mortality in patients with SARS-CoV‑2 infection.

AIM

To investigate the potential prognostic value of peripheral blood eosinophil count on all-cause mortality of patients hospitalized with SARS-CoV‑2 infection, as well as to assess the impact of asthma or COPD premorbidity on all-cause mortality.

MATERIAL AND METHODS

We conducted a retrospective registry-based cohort study. Survival analysis was performed by employing the Cox proportional hazards regression model at 30 days of follow-up. Prognostic value of eosinophil count on all-cause mortality was assessed using receiver-operating characteristic (ROC) curve analysis.

RESULTS

A total of 5653 participants were included in the study. Our model did not reveal that pre-existing asthma or COPD is a statistically significant covariate for all-cause mortality but, indicated that higher eosinophil count at admission might have a protective effect (hazard ratio, HR 0.13 (95% confidence interval, CI 0.06-0.27), p = 0.0001). ROC curve analysis indicates cut-off value of 20 cells/mm³ (81% specificity; 30.9% sensitivity).

CONCLUSION

Our results indicate that eosinophil count at hospital admission might have a potential prognostic role for all-cause mortality at 30 days of follow-up; however this was not demonstrated for pre-existing obstructive lung diseases.

Immune Dynamics Involved in Acute and Convalescent COVID-19 Patients

COVID-19 is a viral disease that has caused millions of deaths around the world since 2020. Many strategies have been developed to manage patients in critical conditions; however, comprehension of the immune system is a key factor in viral clearance, tissue repairment, and adaptive immunity stimulus. Participation of immunity has been identified as a major factor, along with biomarkers, prediction of clinical outcomes, and antibody production after infection. Immune cells have been proposed not only as a hallmark of severity, but also as a predictor of clinical outcomes, while dynamics of inflammatory molecules can also induce worse consequences for acute patients. For convalescent patients, mild disease was related to higher antibody production, although the factors related to the specific antibodies based on a diversity of antigens were not clear. COVID-19 was explored over time; however, the study of immunological predictors of outcomes is still lacking discussion, especially in convalescent patients. Here, we propose a review using previously published studies to identify immunological markers of COVID-19 outcomes and their relation to antibody production to further contribute to the clinical and laboratorial management of patients.

Dissecting Phenotype from Genotype with Clinical Isolates of SARS-CoV-2 First Wave Variants

The emergence and availability of closely related clinical isolates of SARS-CoV-2 offers a unique opportunity to identify novel nonsynonymous mutations that may impact phenotype. Global sequencing efforts show that SARS-CoV-2 variants have emerged and then been replaced since the beginning of the pandemic, yet we have limited information regarding the breadth of variant-specific host responses. Using primary cell cultures and the K18-hACE2 mouse, we investigated the replication, innate immune response, and pathology of closely related, clinical variants circulating during the first wave of the pandemic. Mathematical modeling of the lung viral replication of four clinical isolates showed a dichotomy between two B.1. isolates with significantly faster and slower infected cell clearance rates, respectively. While isolates induced several common immune host responses to infection, one B.1 isolate was unique in the promotion of eosinophil-associated proteins IL-5 and CCL11. Moreover, its mortality rate was significantly slower. Lung microscopic histopathology suggested further phenotypic divergence among the five isolates showing three distinct sets of phenotypes: (i) consolidation, alveolar hemorrhage, and inflammation, (ii) interstitial inflammation/septal thickening and peribronchiolar/perivascular lymphoid cells, and (iii) consolidation, alveolar involvement, and endothelial hypertrophy/margination. Together these findings show divergence in the phenotypic outcomes of these clinical isolates and reveal the potential importance of nonsynonymous mutations in nsp2 and ORF8.

A Nomogram for Predicting Delayed Viral Shedding in Non-Severe SARS-CoV-2 Omicron Infection

Purpose

The Omicron variant of SARS-CoV-2 has emerged as a significant global concern, characterized by its rapid transmission and resistance to existing treatments and vaccines. However, the specific hematological and biochemical factors that may impact the clearance of Omicron variant infection remain unclear. The present study aimed to identify easily accessible laboratory markers that are associated with prolonged virus shedding in non-severe patients with COVID-19 caused by the Omicron variant.

Patients and Methods

A retrospective cohort study was conducted on 882 non-severe COVID-19 patients who were diagnosed with the Omicron variant in Shanghai between March and June 2022. The least absolute shrinkage and selection operator regression model was used for feature selection and dimensional reduction, and multivariate logistic regression analysis was performed to construct a nomogram for predicting the risk of prolonged SARS-CoV-2 RNA positivity lasting for more than 7 days. The receiver operating characteristic (ROC) curve and calibration curves were used to assess predictive discrimination and accuracy, with bootstrap validation.

Results

Patients were randomly divided into derivation (70%, n = 618) and validation (30%, n = 264) cohorts. Optimal independent markers for prolonged viral shedding time (VST) over 7 days were identified as Age, C-reactive protein (CRP), platelet count, leukocyte count, lymphocyte count, and eosinophil count. These factors were subsequently incorporated into the nomogram utilizing bootstrap validation. The area under the curve (AUC) in the derivation (0.761) and validation (0.756) cohorts indicated good discriminative ability. The calibration curve showed good agreement between the nomogram-predicted and actual patients with VST over 7 days.

Conclusion

Our study confirmed six factors associated with delayed VST in non-severe SARS-CoV-2 Omicron infection and constructed a Nomogram which may assist non-severely affected patients to better estimate the appropriate length of self-isolation and optimize their self-management strategies.

Eosinophils and basophils in severe fever with thrombocytopenia syndrome patients: Risk factors for predicting the prognosis on admission

BACKGROUND

Severe fever with thrombocytopenia syndrome (SFTS) virus (SFTSV) is an emerging tick-borne phlebovirus with a high fatality rate. Previous studies have demonstrated the poor prognostic role of eosinophils (EOS) and basophils (BAS) in predicting multiple viral infections. This study aimed to explore the role of EOS and BAS in predicting prognosis of patients with SFTS.

METHODOLOGY

A total of 194 patients with SFTS who were admitted to Yantai City Hospital from November 2019 to November 2021 were included. Patients' demographic and clinical data were collected. According to the clinical prognosis, they were divided into survival and non-survival groups. Independent risk factors were determined by univariate and multivariate logistic regression analyses.

FINDINGS

There were 171 (88.14%) patients in the survived group and 23 (11.86%) patients in the non-survived group. Patients' mean age was 62.39 ± 11.85 years old, and the proportion of males was 52.1%. Older age, neurological manifestations, hemorrhage, chemosis, and increased levels of laboratory variables, such as EOS% and BAS% on admission, were found in the non-survival group compared with the survival group. EOS%, BAS%, aspartate aminotransferase (AST), direct bilirubin (DBIL), and older age on admission were noted as independent risk factors for poor prognosis of SFTS patients. The combination of the EOS% and BAS% had an area under the curve (AUC) of (0.82; 95% CI: 0.725, 0.932, P = 0.000), which showed an excellent performance in predicting prognosis of patients with SFTS compared with neutrophil-to-lymphocyte ratio (NLR), and both exhibited a satisfactory performance in predicting poor prognosis compared with De-Ritis ratio (AST/alanine aminotransferase (ALT) ratio). EOS% and BAS% were positively correlated with various biomarkers of tissue damage and the incidence of neurological complications in SFTS patients.

CONCLUSION

EOS% and BAS% are effective predictors of poor prognosis of patients with early-stage SFTS. The combination of EOS% and BAS% was found as the most effective approach.

Evaluating the serum ferritin levels of COVID-19 patients from Basra

Coronavirus disease 19, "COVID-19, "is occurred by a coronavirus called (SARS CoV-2), which causes severe infection in many infected persons. Early Identifying risk factors for this disease can significantly help manage critical cases and save patients' lives. This study aimed to assess the predictive value of the ferritin, the erythrocyte sedimentation rate ″ESR″, the C-reactive protein ″CRP ″, and white blood cell ″WBC″. Positive cases of COVID-19 were confirmed by "real-time polymerase chain reaction." From the patient's records were obtained demographic data and laboratory investigations were. According to clinical syndromes, patients were categorized into two groups, including COVID -19 patients with severe and non-severe diseases. Of 305 COVID-19 patients, they have a mean age of 42.73 ± 16.37 years, 59.01% of patients are female, and 40.99% are male. The levels of ferritin were variable in COVID-19 patients, our results revealed that18.68% had increased serum ferritin in patients, and the ESR, as well as CRP, were high in most patients; it's above the normal range. 4.91% of patients had decreased WBC, and the result showed lymphopenia in 1.96%. Neutrophils were above the normal range in 14.75% of patients, and 2.95% of patients had decreased serum platelets, a significant difference in WBC, Lymphocytes, Neutrophils and Basophils between severe and non-severe COVID-19 patients (p<0.05). A positive correlation was observed between the levels of ferritin and the severity of the disease Keywords: COVID-19, Ferritin, ESR, CRP, WBC

Eosinopenia as Predictor of Poor Outcome in Hospitalized COVID-19 Adult Patients from Waves 1 and 2 of 2020 Pandemic

During SARS-CoV-2 infection, eosinopenia may reflect a hyperactive immune response. In this study of hospitalized COVID-19 patients, we aimed to better understand the prognostic value of severe eosinopenia (absolute eosinophil count = 0 G/L) and decipher its underlying mechanisms. We retrospectively analyzed the records of COVID-19 patients hospitalized from March to June 2020 in three university hospitals in Marseille, France. We assessed the association between severe eosinopenia and a composite poor outcome in these patients, including the need for oxygen supplementation at >6 L/min, ICU admission, and in-hospital death. Among the 551 COVID-19 patients included in this study, severe eosinopenia was found in 228 (51%) of them on admission to hospital and was associated with a composite poor outcome using multivariate analysis (OR = 2.58; CI95 [1.77−3.75]; p < 0.0001). We found a significant association between the presence of severe eosinopenia on admission and the elevation in C-reactive protein, ferritin, IP-10, and suPAR. The histological findings in a series of 37 autopsies from patients who died from severe COVID-19 and presented with severe eosinopenia showed no pulmonary eosinophil trapping. Severe eosinopenia can be a reliable biomarker associated with a composite poor outcome in hospitalized COVID-19 adult patients. It may reflect the magnitude of immune hyperactivation during severe-to-critical COVID-19.

Cytokine Profiling in Different SARS-CoV-2 Genetic Variants

This study is a successor of our previous work concerning changes in the chemokine profile in infection that are associated with different SARS-CoV-2 genetic variants. The goal of our study was to take into account both the virus and the host immune system by assessing concentrations of cytokines in patients infected with different SARS-CoV-2 variants (ancestral Wuhan strain, Alpha, Delta and Omicron). Our study was performed on 340 biological samples taken from COVID-19 patients and healthy donors in the timespan between May 2020 and April 2022. We performed genotyping of the virus in nasopharyngeal swabs, which was followed by assessment of cytokines' concentration in blood plasma. We noted that out of nearly 30 cytokines, only four showed stable elevation independently of the variant (IL-6, IL-10, IL-18 and IL-27), and we believe them to be 'constant' markers for COVID-19 infection. Cytokines that were studied as potential biomarkers lose their diagnostic value as the virus evolves, and the specter of potential targets for predictive models is narrowing. So far, only four cytokines (IL-6, IL-10, IL-18, and IL-27) showed a consistent rise in concentrations independently of the genetic variant of the virus. Although we believe our findings to be of scientific interest, we still consider them inconclusive; further investigation and comparison of immune responses to different variants of SARS-CoV-2 is required.

White Blood Cells, COVID-19, and Mendelian Randomization

Many observational studies have shown an association between the severity of COVID-19 and the different white blood cell counts, most frequently neutrophils, lymphocytes, and eosinophils. The studies aimed to predict the prognosis, and therefore, a causal relationship was unnecessary. However, if we begin to look at these biomarkers as potential therapeutic targets, then causality is essential. Observational studies cannot prove a causal relationship, and randomized trials are not always feasible. In this case, Mendelian randomization studies, considered more valid than observational studies, could add to the arguments for causality. Two Mendelian randomization studies tested for a causal relationship between the number of different white cell populations and COVID-19 severity, but their results are different; therefore, the problem of causality is not settled in this case.

Cytokine Storm Signature in Patients with Moderate and Severe COVID-19

Hypercytokinemia, found in SARS-CoV-2 infection, contributes to multiple organ dysfunctions with acute respiratory distress syndrome, shock etc. The aim of this study was to describe cytokine storm signatures in patients with acute COVID-19 and to investigate their influence on severity of the infection. Plasma levels of 47 cytokines were investigated in 73 patients with moderate and severe COVID-19 (41 and 32, respectively) and 11 healthy donors (HD). The most elevated levels comparing patients and the HD were observed for seven pro-inflammatory cytokines (IL-6, IL-8, IL-15, IL-18, IL-27, IFNγ, TNFα), three chemokines (GROα, IP-10, MIG), two anti-inflammatory cytokines (IL-1RA, IL-10), and two growth factors (G-CSF, M-CSF). The patients with severe disease had significantly higher levels of FGF-2/FGF-basic, IL-1β, and IL-7 compared to the HD. The two groups of patients differed from each other only based on the levels of EGF, eotaxin, and IL-12 p40. Pneumonia lung injury, characterized by computer tomography, positively correlated with levels of EGF, IP-10, MCP-3 levels and negatively with IL-12 p40. Pro-inflammatory factors including IL-6, TNFα, and IP-10 negatively correlated with the frequency of the circulating T-helper17-like cells (Th17-like) and follicular Th cells that are crucial to develop SARS-CoV-2-specific plasma cells and memory B cells. Obtained data on the cytokine levels illustrate their influence on progression and severity of COVID-19.

Effect of Nonalcoholic Fatty Liver Disease (NAFLD) on COVID-19: A Single-Center Study of 3983 Patients With Review of Literature

Background

The presence of metabolic syndrome (MS) is associated with increased disease severity in patients with coronavirus disease 2019 (COVID-19). Non-alcoholic fatty liver disease (NAFLD) associated with or without MS may be related to increased morbidity and mortality in COVID-19, but large Indian studies are lacking. The present study was carried out to assess the impact of NAFLD on the clinical outcomes in patients with COVID-19 infection.

Methods

All patients with COVID-19 hospitalized at a tertiary care hospital in eastern India from April 4 to December 31, 2020, were included in the study. Patients who underwent non-contrast CT (NCCT) chest were evaluated for the presence of hepatic steatosis based on a validated criterion liver attenuation (HU) value lower than the spleen, absolute liver attenuation lower than 40 HU, and liver to spleen attenuation ratio less than 1. Patients were divided into two groups, those with or without fatty liver. Baseline characteristics including age, sex, liver function tests, and outcomes including duration of hospital stay and mortality were compared.

Results

A total of 6003 COVID-19-positive patients were admitted during the study period. Of these patients, 214 children (<18 years) with COVID-19 infection were excluded. One hundred and eight patients with a history of significant ethanol abuse were excluded from the analysis. NCCT scan was not done in 1698 patients. Finally, 3983 patients were included in the study. They were divided into two groups depending on the presence or absence of NAFLD. Of the 3983 patients, 814 (20.4%) had NAFLD. Overall in-hospital mortality among the study group was 6.4%. The mortality rate among patients with NAFLD was 6.7% while that in patients without fatty liver was 6% (P=0.381). Similarly, the mean duration of hospital stay was also comparable between both the groups (10.63±7.2days vs 10.65±6.6 days;P=0.66). Prevalence of NAFLD was similar in survivors and non-survivors; 759 of 2981 patients (25.4%) and 55 of 188 patients 29.2% (P=0.381), respectively. On univariate analysis, male sex, older age, elevated alanine aminotransferase (ALT), aspartate aminotransferase (AST), and gamma-glutamyl transpeptidase (GGT) along with low serum albumin and low absolute eosinophil counts (AEC) were associated with higher mortality. However, on multivariate analysis, only older age, male sex, and low albumin levels were associated with higher mortality. Surprisingly, a sub-group analysis showed that females without NAFLD were at a higher risk of mortality than those with fatty liver (4.9% vs 12.3%; P=0.006). Similarly, patients with lower AST levels had higher mortality compared to patients with significantly elevated AST levels (more than two times the upper limit of normal (ULN)), irrespective of the presence of fatty liver.

Conclusions

The prevalence of fatty liver in severe acute respiratory syndrome coronavirus 2 (SARS CoV-2) infected patients is similar to the general population in India, the presence of which is not a predictor of severe disease. However, mortality is higher in males and elderly patients.

T helper cell subsets and related target cells in acute COVID-19

Current review presents a brief overview of the immune system dysregulation during acute COVID-19 and illustrates the main alterations in peripheral blood CD4+ T-cell (Th) subsets as well as related target cells. Effects of dendritic cell dysfunction induced by SARS-CoV-2 exhibited decreased expression of cell-surface HLA-DR, CCR7 as well as co-stimulatory molecules CD80 and CD86, suggesting reduced antigen presentation, migratory and activation capacities of peripheral blood dendritic cells. SARS-CoV-2-specific Th cells could be detected as early as days 24 post-symptom onset, whereas the prolonged lack of SARS-CoV-2-specific Th cells was associated with severe and/or poor COVID-19 outcome. Firstly, in acute COVID-19 the frequency of Th1 cell was comparable with control levels, but several studies have reported about upregulated inhibitory immune checkpoint receptors and exhaustion-associated molecules (TIM3, PD-1, BTLA, TIGIT etc.) on circulating CD8+ T-cells and NK-cells, whereas the macrophage count was increased in bronchoalveolar lavage (BAL) samples. Next, type 2 immune responses are mediated mainly by Th2 cells, and several studies have revealed a skewing towards dominance of Th2 cell subset in peripheral blood samples from patients with acute COVID-19. Furthermore, the decrease of circulating main Th2 target cells basophiles and eosinophils were associated with severe COVID-19, whereas the lung tissue was enriched with mast cells and relevant mediators released during degranulation. Moreover, the frequency of peripheral blood Th17 cells was closely linked to COVID-19 severity, so that low level of Th17 cells was observed in patients with severe COVID-19, but in BAL the relative number of Th17 cells as well as the concentrations of relevant effector cytokines were dramatically increased. It was shown that severe COVID-19 patients vs. healthy control had higher relative numbers of neutrophils if compared, and the majority of patients with COVID-19 had increased frequency and absolute number of immature neutrophils with altered ROS production. Finally, the frequency of Tfh cells was decreased during acute COVID-19 infection. Elevated count of activated Tfh were found as well as the alterations in Tfh cell subsets characterized by decreased regulatory Tfh1 cell and increased pro-inflammatory Tfh2 as well as Tfh17 cell subsets were revealed. Descriptions of peripheral blood B cells during an acute SARS-CoV-2 infection werev reported as relative B cell lymphopenia with decreased frequency of nave and memory B cell subsets, as well as increased level of CD27hiCD38hiCD24 plasma cell precursors and atypical CD21low B cells. Thus, the emerging evidence suggests that functional alterations occur in all Th cell subsets being linked with loss-of-functions of main Th cell subsets target cells. Furthermore, recovered individuals could suffer from long-term immune dysregulation and other persistent symptoms lasting for many months even after SARS-CoV-2 elimination, a condition referred to as post-acute COVID-19 syndrome.

Analysis of COVID-19 inpatients in France during first lockdown of 2020 using explainability methods

The COVID-19 pandemic rapidly puts a heavy pressure on hospital centers, especially on intensive care units. There was an urgent need for tools to understand typology of COVID-19 patients and identify those most at risk of aggravation during their hospital stay. Data included more than 400 patients hospitalized due to COVID-19 during the first wave in France (spring of 2020) with clinical and biological features. Machine learning and explainability methods were used to construct an aggravation risk score and analyzed feature effects. The model had a robust AUC ROC Score of 81%. Most important features were age, chest CT Severity and biological variables such as CRP, O2 Saturation and Eosinophils. Several features showed strong non-linear effects, especially for CT Severity. Interaction effects were also detected between age and gender as well as age and Eosinophils. Clustering techniques stratified inpatients in three main subgroups (low aggravation risk with no risk factor, medium risk due to their high age, and high risk mainly due to high CT Severity and abnormal biological values). This in-depth analysis determined significantly distinct typologies of inpatients, which facilitated definition of medical protocols to deliver the most appropriate cares for each profile.

Graphical Abstract

Dysregulated Immune Responses in SARS-CoV-2-Infected Patients: A Comprehensive Overview

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first detected in humans more than two years ago and caused an unprecedented socio-economic burden on all countries around the world. Since then, numerous studies have attempted to identify various mechanisms involved in the alterations of innate and adaptive immunity in COVID-19 patients, with the ultimate goal of finding ways to correct pathological changes and improve disease outcomes. State-of-the-art research methods made it possible to establish precise molecular mechanisms which the new virus uses to trigger multisystem inflammatory syndrome and evade host antiviral immune responses. In this review, we present a comprehensive analysis of published data that provide insight into pathological changes in T and B cell subsets and their phenotypes, accompanying the acute phase of the SARS-CoV-2 infection. This knowledge might help reveal new biomarkers that can be utilized to recognize case severity early as well as to provide additional objective information on the effective formation of SARS-CoV-2-specific immunity and predict long-term complications of COVID-19, including a large variety of symptoms termed the 'post-COVID-19 syndrome'.

Immunouniverse of SARS-CoV-2

SARS-CoV-2 virus has become a global health problem that has caused millions of deaths worldwide. The infection can present with multiple clinical features ranging from asymptomatic or mildly symptomatic patients to patients with severe or critical illness that can even lead to death. Although the immune system plays an important role in pathogen control, SARS-CoV-2 can drive dysregulation of this response and trigger severe immunopathology. Exploring the mechanisms of the immune response involved in host defense against SARS-CoV-2 allows us to understand its immunopathogenesis and possibly detect features that can be used as potential therapies to eliminate the virus. The main objective of this review on SARS-CoV-2 is to highlight the interaction between the virus and the immune response. We explore the function and action of the immune system, the expression of molecules at the site of infection that cause hyperinflammation and hypercoagulation disorders, the factors leading to the development of pneumonia and subsequent severe acute respiratory distress syndrome which is the leading cause of death in patients with COVID-19.

Immunoediting in SARS-CoV-2: Mutual relationship between the virus and the host

Immunoediting is a well-known concept that occurs in cancer through three steps of elimination, equilibrium, and escape (3Es), where the immune system first suppresses the growth of tumor cells and then promotes them towards the malignancy. This phenomenon has been conceptualized in some chronic viral infections such as HTLV-1 and HIV by obtaining the resistance to elimination and making a persistent form of infected cells especially in untreated patients. Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a heterogeneous disease characterizing from mild/asymptomatic to severe/critical courses with some behavioral aspects in an immunoediting setting. In this context, a coordinated effort between innate and adaptive immune system leads to detection and destruction of early infection followed by equilibrium between virus-specific responses and infected cells, which eventually ends up with an uncontrolled inflammatory response in severe/critical patients. Although the SARS-CoV-2 applies several escape strategies such as mutations in viral epitopes, modulating the interferon response and inhibiting the MHC I molecules similar to the cancer cells, the 3Es hallmark may not occur in all clinical conditions. Here, we discuss how the lesson learnt from cancer immunoediting and accurate understanding of these pathophysiological mechanisms helps to develop more effective therapeutic strategies for COVID-19.

Evolution of hospitalized patient characteristics through the first three COVID-19 waves in Paris area using machine learning analysis

Characteristics of patients at risk of developing severe forms of COVID-19 disease have been widely described, but very few studies describe their evolution through the following waves. Data was collected retrospectively from a prospectively maintained database from a University Hospital in Paris area, over a year corresponding to the first three waves of COVID-19 in France. Evolution of patient characteristics between non-severe and severe cases through the waves was analyzed with a classical multivariate logistic regression along with a complementary Machine-Learning-based analysis using explainability methods. On 1076 hospitalized patients, severe forms concerned 29% (123/429), 31% (66/214) and 18% (79/433) of each wave. Risk factors of the first wave included old age (≥ 70 years), male gender, diabetes and obesity while cardiovascular issues appeared to be a protective factor. Influence of age, gender and comorbidities on the occurrence of severe COVID-19 was less marked in the 3rd wave compared to the first 2, and the interactions between age and comorbidities less important. Typology of hospitalized patients with severe forms evolved rapidly through the waves. This evolution may be due to the changes of hospital practices and the early vaccination campaign targeting the people at high risk such as elderly and patients with comorbidities.

Longitudinally monitored immune biomarkers predict the timing of COVID-19 outcomes

The clinical outcome of SARS-CoV-2 infection varies widely between individuals. Machine learning models can support decision making in healthcare by assessing fatality risk in patients that do not yet show severe signs of COVID-19. Most predictive models rely on static demographic features and clinical values obtained upon hospitalization. However, time-dependent biomarkers associated with COVID-19 severity, such as antibody titers, can substantially contribute to the development of more accurate outcome models. Here we show that models trained on immune biomarkers, longitudinally monitored throughout hospitalization, predicted mortality and were more accurate than models based on demographic and clinical data upon hospital admission. Our best-performing predictive models were based on the temporal analysis of anti-SARS-CoV-2 Spike IgG titers, white blood cell (WBC), neutrophil and lymphocyte counts. These biomarkers, together with C-reactive protein and blood urea nitrogen levels, were found to correlate with severity of disease and mortality in a time-dependent manner. Shapley additive explanations of our model revealed the higher predictive value of day post-symptom onset (PSO) as hospitalization progresses and showed how immune biomarkers contribute to predict mortality. In sum, we demonstrate that the kinetics of immune biomarkers can inform clinical models to serve as a powerful monitoring tool for predicting fatality risk in hospitalized COVID-19 patients, underscoring the importance of contextualizing clinical parameters according to their time post-symptom onset.

Clinical and hematological characteristics of 300 COVID-19 patients in Erbil, Kurdistan Region, Iraq

Background

COVID-19 primarily presents as a respiratory tract infection, but studies indicate that it could be considered a systemic disease that can spread to affect multiple organ systems, including respiratory, cardiovascular, gastrointestinal, hematopoietic, neurological, and immune systems.

Objective

To describe and analyze the clinical and hematological characteristics of 300 hospitalized COVID-19 patients in Erbil, Kurdistan.

Methods

This retrospective study included 300 patients of any age admitted to hospital due to confirmed COVID-19 between September 2020 and February 2021. Cases were diagnosed by reverse transcriptase polymerase chain reaction assays of nasopharyngeal swab specimens.

Results

The highest proportion of patients were aged 21–40 years. The most common symptoms among the patients were myalgia (66.7%), fatigue (62.3%), headache (50.7%), and chest pain (52.7%). Differences in hematological and biochemical parameters were observed between deceased and recovered patients. Only the mid-range absolute count percentage (MID%) was significantly higher in the recovered patients than in the deceased ones (6.41% vs. 4.48, p = 0.019). Death was significantly higher among older patients (>40 years) than younger ones (≤40 years) (6.8% vs. 1.3%, p = 0.015), diabetic than non-diabetic (10.8% vs. 3%, p = 0.047), and those having chronic diseases than those without chronic diseases (10.6% vs. 2.1%, p = 0.006).

Conclusions

Different hematological and biochemical parameter findings were observed among the COVID-19 patients. Low MID%, older age, and presence of diabetes mellitus and chronic disease were significantly associated with death among COVID-19 patients.

Active pulmonary tuberculosis and coronavirus disease 2019: A systematic review and meta-analysis

OBJECTIVE

The proportion of COVID-19 patients having active pulmonary tuberculosis, and its impact on COVID-19 related patient outcomes, is not clear. We conducted this systematic review to evaluate the proportion of patients with active pulmonary tuberculosis among COVID-19 patients, and to assess if comorbid pulmonary tuberculosis worsens clinical outcomes in these patients.

METHODS

We queried the PubMed and Embase databases for studies providing data on (a) proportion of COVID-19 patients with active pulmonary tuberculosis or (b) severe disease, hospitalization, or mortality among COVID-19 patients with and without active pulmonary tuberculosis. We calculated the proportion of tuberculosis patients, and the relative risk (RR) for each reported outcome of interest. We used random-effects models to summarize our data.

RESULTS

We retrieved 3,375 citations, and included 43 studies, in our review. The pooled estimate for proportion of active pulmonary tuberculosis was 1.07% (95% CI 0.81%-1.36%). COVID-19 patients with tuberculosis had a higher risk of mortality (summary RR 1.93, 95% CI 1.56-2.39, from 17 studies) and for severe COVID-19 disease (summary RR 1.46, 95% CI 1.05-2.02, from 20 studies), but not for hospitalization (summary RR 1.86, 95% CI 0.91-3.81, from four studies), as compared to COVID-19 patients without tuberculosis.

CONCLUSION

Active pulmonary tuberculosis is relatively common among COVID-19 patients and increases the risk of severe COVID-19 and COVID-19-related mortality.

Predictive Value of Eosinophil Count on COVID-19 Disease Progression and Outcomes, a Retrospective Study of Leishenshan Hospital in Wuhan, China

BACKGROUND

The potential protective role of eosinophils in the COVID-19 pandemic has aroused great interest, given their potential virus clearance function and the infection resistance of asthma patients to this coronavirus. However, it is unknown whether eosinophil counts could serve as a predictor of the severity of COVID-19.

METHODS

A total of 1004 patients with confirmed COVID-19 who were admitted to Leishenshan Hospital in Wuhan, China, were enrolled in this study, including 905 patients in the general ward and 99 patients in the intensive care unit (ICU). We reviewed their medical data to analyze the association between eosinophils and ICU admission and death.

RESULTS

Of our 1004 patients with COVID-19, low eosinophil counts/ratios were observed in severe cases. After adjusting for confounders that could have affected the outcome, we found that eosinophil counts might not be a predictor of ICU admission. In 99 ICU patients, 58 of whom survived and 41 of whom died, low eosinophil level was an indicator of death in severe COVID-19 patients with a cutoff value of 0.04 × 10⁹/L, which had an area under the curve of 0.665 (95% CI = 1.089-17.839; P = .045) with sensitivity and specificity of 0.569 and 0.7317, respectively.

CONCLUSION

Our research revealed that a low eosinophil level is a predictor of death in ICU patients rather than a cause of ICU admission.

Impaired Antibody-Dependent Cellular Cytotoxicity in a Spanish Cohort of Patients With COVID-19 Admitted to the ICU

SARS-CoV-2 infection causes COVID-19, ranging from mild to critical disease in symptomatic subjects. It is essential to better understand the immunologic responses occurring in patients with the most severe outcomes. In this study, parameters related to the humoral immune response elicited against SARS-CoV-2 were analysed in 61 patients with different presentations of COVID-19 who were recruited in Hospitals and Primary Healthcare Centres in Madrid, Spain, during the first pandemic peak between April and June 2020. Subjects were allocated as mild patients without hospitalization, severe patients hospitalized or critical patients requiring ICU assistance. Critical patients showed significantly enhanced levels of B cells with memory and plasmablast phenotypes, as well as higher levels of antibodies against SARS-CoV-2 with neutralization ability, which were particularly increased in male gender. Despite all this, antibody-dependent cell-mediated cytotoxicity was defective in these individuals. Besides, patients with critical COVID-19 also showed increased IgG levels against herpesvirus such as CMV, EBV, HSV-1 and VZV, as well as detectable CMV and EBV viremia in plasma. Altogether, these results suggest an enhanced but ineffectual immune response in patients with critical COVID-19 that allowed latent herpesvirus reactivation. These findings should be considered during the clinical management of these patients due to the potential contribution to the most severe disease during SARS-CoV-2 infection.

The Use of Eosinophil Count in Predicting the Need of Coronavirus Disease 2019 Patient for Treatment in Intensive Care Unit

BACKGROUND: Identification of coronavirus disease 2019 (COVID-19) patients who have the potential to become critical cases at an early stage and providing aggressive therapy can reduce the mortality rate. AIM: This study aims to determine the diagnostic value and differences of eosinophil counts in patients with COVID-19 who require treatment in intensive care unit (ICU) and non-ICU. METHOD: The prospective study was conducted on 382 patients with confirmed COVID-19 who were hospitalized from May to September 2020. Samples were obtained through consecutive sampling techniques. Mann–Whitney analysis was used to determine the difference of eosinophil counts in COVID-19 patients who require treatment in ICU and non-ICU. Receiver operating curve analysis was used to determine the diagnostic value of eosinophil count to predict the need of COVID-19 patients for treatment in ICU. RESULTS: There is a significant difference in the absolute and percentage eosinophil count in COVID-19 patients who need treatment in ICU and non-ICU. The area under the curve of absolute and percentage eosinophil count to predict the need of COVID-19 patients for treatment in ICU is 0.659 and 0.738, respectively. The best cutoff value, sensitivity and specificity of absolute and percentage eosinophil count is <0.025 × 103 μL and <0.25%; 77.7% and 78.3%; and 50.0% and 57.1%, respectively. CONCLUSIONS: The eosinophil count can be used as a biomarker to predict the need of COVID-19 patients for treatment in ICU.

Cell Population Data and Serum Polyclonal Immunoglobulin Free Light Chains in the Assessment of COVID-19 Severity

Distinguishing between severe and nonsevere COVID-19 to ensure adequate healthcare quality and efficiency is a challenge for the healthcare system. The aim of this study was to assess the usefulness of CBC parameters together with analysis of FLC serum concentration in risk stratification of COVID-19. Materials and methods: CBC was analyzed in 735 COVID ICU, COVID non-ICU, and non-COVID ICU cases. FLC concentration was analyzed in 133 of them. Results: COVID ICU had neutrophils and lymphocytes with the greatest size, granularity, and nucleic acid content. Significant differences in concentrations of κ and λ FLCs were shown between COVID ICU and COVID non-ICU. However, no difference was found in the κ/λ ratio between these groups, and the ratio stayed within the reference value, which indicates the presence of polyclonal FLCs. FLC κ measurement has significant power to distinguish between severe COVID-19 and nonsevere COVID-19 (AUC = 0.7669), with a sensitivity of 86.67% and specificity of 93.33%. The κ coefficients’ odds ratio of 3.0401 was estimated. Conclusion: It can be concluded that the results obtained from the measure of free light immunoglobulin concentration in serum are useful in distinguishing between severe and nonsevere COVID-19.

Emerging Evidence for Pleiotropism of Eosinophils

Eosinophils are complex granulocytes with the capacity to react upon diverse stimuli due to their numerous and variable surface receptors, which allows them to respond in very different manners. Traditionally believed to be only part of parasitic and allergic/asthmatic immune responses, as scientific studies arise, the paradigm about these cells is continuously changing, adding layers of complexity to their roles in homeostasis and disease. Developing principally in the bone marrow by the action of IL-5 and granulocyte macrophage colony-stimulating factor GM-CSF, eosinophils migrate from the blood to very different organs, performing multiple functions in tissue homeostasis as in the gastrointestinal tract, thymus, uterus, mammary glands, liver, and skeletal muscle. In organs such as the lungs and gastrointestinal tract, eosinophils are able to act as immune regulatory cells and also to perform direct actions against parasites, and bacteria, where novel mechanisms of immune defense as extracellular DNA traps are key factors. Besides, eosinophils, are of importance in an effective response against viral pathogens by their nuclease enzymatic activity and have been lately described as involved in severe acute respiratory syndrome coronavirus SARS-CoV-2 immunity. The pleiotropic role of eosinophils is sustained because eosinophils can be also detrimental to human physiology, for example, in diseases like allergies, asthma, and eosinophilic esophagitis, where exosomes can be significant pathophysiologic units. These eosinophilic pathologies, require specific treatments by eosinophils control, such as new monoclonal antibodies like mepolizumab, reslizumab, and benralizumab. In this review, we describe the roles of eosinophils as effectors and regulatory cells and their involvement in pathological disorders and treatment.

SARS-CoV-2 Infection: Differences in Hematological Parameters Between Adults and Children

Since December 2019, corona virus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a global pandemic, posing a huge threat to human health, and the current epidemic prevention situation is still severe. Hematological parameters directly reflect the damage of SARS-CoV-2 to human blood cells, which can better assess the severity and prognosis of patients infected with COVID-19, but hematological parameters have some differences between adults and children. This article comprehensively reviews the differences in hematological parameters between adults and children after SARS-CoV-2 infection, and provides a reference for the diagnosis and treatment of COVID-19.

Mortality Predictors in Patients Diagnosed with COVID-19 in the Emergency Department: ECG, Laboratory and CT

Background and Objectives: The aim of this study was to investigate parameters that can be used to predict mortality in patients diagnosed with COVID-19 in the emergency department (ED). Materials and Methods: Patients diagnosed with COVID-19 in the ED were included in this prospective study. The patients were divided into two groups. The surviving patients were included in Group 1 (survivors), and the patients who died were included in Group 2 (non-survivors). The electrocardiogram (ECG), laboratory results and chest computerized tomography (CCT) findings of the two groups were compared. The CCT images were classified according to the findings as normal, mild, moderate and severe. Results: Of the 419 patients included in the study, 347 (83%) survived (survivor) and 72 (17%) died (non-survivor). The heart rate and respiratory rate were found to be higher, and the peripheral oxygen saturation (SpO2) and diastolic blood pressure (DBP) were found to be lower in the non-survivor patients. QRS and corrected QT interval (QTc) were measured as longer in the non-survivor patients. In the CCT images, 79.2% of the non-survivor patients had severe findings, while 11.5% of the survivor patients had severe findings. WBC, neutrophil, NLR, lactate, D-dimer, fibrinogen, C- Reactive Protein (CRP), urea, creatinine, creatine kinase-MB (CK-MB) and hs-Troponin I levels were found to be higher and partial pressure of carbon dioxide (PCO2), base excess (BE), bicarbonate (HCO3), lymphocyte eosinophil levels were found to be lower in non-survivor patients. The highest AUC was calculated at the SpO2 level and the eosinophil level. Conclusions: COVID-19 is a fatal disease whose mortality risk can be estimated when the clinical, laboratory and imaging studies of the patients are evaluated together in the ED. SpO2 that is measured before starting oxygen therapy, the eosinophil levels and the CT findings are all important predictors of mortality risk.

Characterization of COPD Admissions During the First COVID-19 Outbreak

Purpose

Exacerbations of COPD (ECOPD) are a frequent cause of hospitalization that seemed to ameliorate during the COVID outbreak. We aimed to evaluate the clinical characteristics of COPD-related hospital admissions and mortality in relation to the presence of COVID-19.

Patients and Methods

We conducted a case-control study of patients admitted in four teaching hospitals throughout Spain between March 15 and April 30, 2020. Hospital admissions of respiratory cause with and without PCR-proven SARS-CoV-2 infection in patients with COPD were evaluated. Baseline and episode-related clinical characteristics were analyzed. Logistic regression analysis was performed to evaluate the risk for mortality.

Results

During the study period, 2101 patients were admitted for respiratory worsening, 1200 (57.1%) with COVID-19. A total of 228 (10.8%) were admitted due to COPD worsening, of whom 52 (22.8%) tested positive for COVID-19. COPD patients with COVID-19, when compared to those without COVID-19, were more frequently males with better lung function (FEV₁ postbronchodilator 71% vs 46% respectively, p<0.001) and had higher mortality (44.9% vs 13.6% respectively, p<0.001) despite similar age, comorbidities, total days of hospitalization and admission to intensive care unit. COVID-19 and eosinopenia were the strongest risk factors for mortality in the multivariate analysis in the overall COPD population. Inhaled corticosteroid use was not associated to mortality.

Conclusion

Hospitalizations for ECOPD without COVID-19 were more frequent than COPD with COVID-19 during the first outbreak, but the latter were associated with higher mortality and low eosinophil counts that warrant further analysis.