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

Impact of preoperative inflammatory biomarkers on postoperative pneumonia and one-month pulmonary imaging changes after surgery for non-small cell lung cancer

Background

This study examined the effectiveness of preoperative inflammatory markers in predicting the occurrence of postoperative pneumonia (POP) and clinical outcomes based on chest computed tomography (CT) images in patients who underwent surgical resection for non-small cell lung cancer (NSCLC).

Methods

This retrospective study included NSCLC patients who underwent lung cancer surgery at The First People's Hospital of Jiande between January 2019 and October 2023. Data on demographic characteristics, preoperative inflammatory biomarkers, surgical approach and duration, postoperative outcomes, and CT findings 1 month postoperatively were collected and analyzed. The effectiveness of preoperative inflammatory markers in predicting POP and clinical outcomes 1 month after surgical resection was assessed using propensity score matching.

Results

Among 568 patients, 72 (12.7%) had POP. After matching, 252 patients (POP group: 66; non-POP group: 186) were included in the analysis. The systemic immune-inflammation index (SII) and platelet-to-lymphocyte ratio (PLR) were significantly higher in the POP group than in the non-POP group (433.53 vs. 323.75, P = 0.001; 126.42 vs. 103.64, P < 0.001). The length of hospital stay and the percentage of patients who improved clinically based on chest CT findings 1 month after surgery were significantly higher in the POP group than in the non-POP group (11 days vs. 9 days, P = 0.008; 77.3% vs. 59.7%, P = 0.033). Multivariate analysis showed that PLR and the lymphocyte-to-monocyte ratio (LMR) were independent predictors of POP (AUC of 0.780 and 0.730, both at P < 0.001). However, there were no significant differences in postoperative radiographic outcomes among patients stratified by risk of POP.

Conclusion

PLR and LMR accurately predict POP in surgical patients with NSCLC. Nonetheless, these ratios may not significantly predict radiographic outcomes 1 month after surgical resection.

COVID-19 caused by the Omicron variant in lung transplant recipients: a single center case series

Background

Although coronavirus disease 2019 (COVID-19) is no longer classified as a Public Health Emergency of International Concern by World Health Organization, its global impact persists. Data on its impact in lung transplant recipients (LTRs) from China remain limited. This study aims to share clinical experiences and provide insights into managing LTRs with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.

Methods

We conducted a study on LTRs with COVID-19 caused by the Omicron variant from November 17, 2022, to May 1, 2023. Clinical information was gathered retrospectively through electronic medical records, questionnaires, or follow-up telephone calls.

Results

A total of 227 LTRs were reviewed for infection with Omicron variant. After excluding 49 cases without confirmed SARS-CoV-2 infection, this left a final cohort of 178 infected LTRs, accounting for an infection rate of 78.4% (178/227). Of the patients, 50% (89/178) required hospitalization, with an average hospital stay of 16 days [interquartile range (IQR): 9.5-25.5 days]. Of the 89 hospitalized patients, 41.6% (37/89) eventually progressed to severe or critical disease, forming the severe/critical group (S/C group), while the remaining 58.4% (52/89) had mild or moderate disease (M/M group). In comparison to the M/M group, the S/C group had higher C-reactive protein (CRP) (59.6 vs. 16.8 mg/L, P<0.001), Erythrocyte sedimentation rate (45.5 vs. 22.5 mm/h, P=0.005) and D-dimer level (1.09 vs. 0.65 mg/L, P=0.01), but lower CD4+ T lymphocytes count (217 vs. 427 cells/µL, P=0.004). The S/C group had significantly higher rates of combined pulmonary bacterial infection (67.6% vs. 38.5%, P=0.006) and pulmonary fungal infection (73.0% vs. 38.5%, P=0.001) during the course of COVID-19, nearly double that of the M/M group. In a multivariate logistic analysis, elevated CRP (>41.8 mg/L), combined pulmonary fungal infection, and interstitial lung disease (ILD) as primary disease emerged as high-risk factors for developing the severe disease phenotype following Omicron variant infection in LTRs, with respective odds ORs values of 4.23 [95% confidence interval (CI): 1.68-11.23], 4.76 (95% CI: 1.59-15.64), and 5.13 (95% CI: 1.19-29.17). Receiver operating characteristic (ROC) curve analysis showed that CD4+ T lymphocyte count may be a strong marker for predicting death. At a cutoff of 404 cells/µL, sensitivity was 0.509, specificity 0.999, and area under the curve (AUC) was 0.806 (95% CI: 0.678-0.934). Ultimately, 13 recipients succumbed to COVID-19 related respiratory failure or secondary multiple organ dysfunction, resulting in an overall mortality rate of 7.3% (13/178).

Conclusions

LTRs are at high risk of secondary lung infections after Omicron. Key risk factors for severe disease include CRP >41.8 mg/L, ILD as primary disease, and pulmonary fungal infection. CD4+ T lymphocyte count may predict mortality risk in LTRs with COVID-19.

A Review of the Hematological Picture of Severe COVID-19 Infection

Numerous hematological abnormalities have been documented in COVID-19 patients. We conducted an analysis of 82 articles from PubMed, focusing on the hematological characteristics observed in survivors (S) and non-survivors (NS) with moderate and severe COVID-19 symptoms, respectively. Our review underlines neutrophilia, lymphopenia, and thrombocytopenia as hallmark features of the disease. In severe cases, blood cell microscopy revealed the following abnormalities: i) an increased number of neutrophils, often displaying granularity, toxic granulation, and vacuolization; ii) lymphocytes with a notably blue cytoplasm; iii) several monocytes that contain vacuoles; iv) platelet aggregation; and v) basophilic stippling in red blood cells. Furthermore, scattergram analysis of COVID-19 patients revealed two common features: i) an increased neutrophil population and ii) the presence of a distinctive "sandglass pattern". This review underscores the critical role of hematochemical and cytomorphological blood cell analysis in COVID-19 patients, aiding clinicians in better recognizing and understanding the indicators of disease severity.

Laboratory profiles of patients hospitalized with COVID-19 pneumonia treated with tofacitinib or placebo: a post hoc analysis from the STOP-COVID trial

OBJECTIVE

Tofacitinib, an oral Janus kinase inhibitor, has been tested against a placebo in 289 patients with COVID-19 pneumonia. We analyzed the data from the tofacitinib- and placebo-treated patient cohorts to evaluate the laboratory profiles between baseline and day 7.

METHODS

We performed post hoc analyses on the following laboratory tests over time during the first 7 days after randomization: hemoglobin, leukocytes, neutrophils, lymphocytes, platelets, alanine aminotransferase, and aspartate aminotransferase.

RESULTS

Through the first 7 days after randomization, the levels of hemoglobin, white blood cells, neutrophils, and platelet counts were not significantly different between patients treated with tofacitinib or a placebo (all p>0.05). Non-significant differences were observed in aspartate aminotransferase levels over time between treatment groups, whereas alanine aminotransferase levels (U/L) were higher among tofacitinib-treated patients compared to placebo-treated patients (mean ratio, 1.30 [95% confidence interval (95%CI) = 1.14-1.48; p<0.01)].

CONCLUSION

In patients with COVID-19 pneumonia, the use of tofacitinib compared to placebo did not result in clinically meaningful changes in blood counts or liver enzymes over the first 7 days after randomization.

REGISTRY OF CLINICAL TRIALS

NCT04469114.

Gut Microbiota Improves Prognostic Prediction in Critically Ill COVID-19 Patients Alongside Immunological and Hematological Indicators

The gut microbiota undergoes substantial changes in COVID-19 patients; yet, the utility of these alterations as prognostic biomarkers at the time of hospital admission, and its correlation with immunological and hematological parameters, remains unclear. The objective of this study is to investigate the gut microbiota's dynamic change in critically ill patients with COVID-19 and evaluate its predictive capability for clinical outcomes alongside immunological and hematological parameters. In this study, anal swabs were consecutively collected from 192 COVID-19 patients (583 samples) upon hospital admission for metagenome sequencing. Simultaneously, blood samples were obtained to measure the concentrations of 27 cytokines and chemokines, along with hematological and biochemical indicators. Our findings indicate a significant correlation between the composition and dynamics of gut microbiota with disease severity and mortality in COVID-19 patients. Recovered patients exhibited a higher abundance of Veillonella and denser interactions among gut commensal bacteria compared to deceased patients. Furthermore, the abundance of gut commensal bacteria exhibited a negative correlation with the concentration of proinflammatory cytokines and organ damage markers. The gut microbiota upon admission showed moderate prognostic prediction ability with an AUC of 0.78, which was less effective compared to predictions based on immunological and hematological parameters (AUC 0.80 and 0.88, respectively). Noteworthy, the integration of these three datasets yielded a higher predictive accuracy (AUC 0.93). Our findings suggest the gut microbiota as an informative biomarker for COVID-19 prognosis, augmenting existing immune and hematological indicators.

Association of the C3953T (rs1143634) variant of the interleukin 1 beta gene with the features of a complicated course of COVID-19-associated pneumonia

BACKGROUND

The pro-inflammatory cytokine IL-1 plays an important role in severe COVID-19. A change in IL-1 production may be associated with a mutation in the IL1Β gene. Our study analyzed the impact of the IL1Β gene variants (rs1143634) on disease progression in patients with severe COVID-19 pneumonia, taking into account treatment strategies.

METHODS AND RESULTS

The study enrolled 117 patients with severe COVID-19 pneumonia. The IL1Β gene variants were identified using the polymerase chain reaction-restriction fragment length polymorphism method. In the group of patients, the following genotype frequencies were found based on the investigated rs1143634 variant of the IL1Β gene: CC-65.8%, CT-28.2%, and TT-6.0%. Our results showed that the group of patients with the T allele of the IL1Β gene had higher leukocyte counts (p = 0.040) and more pronounced lymphopenia (p = 0.007). It was determined that patients carrying the T allele stayed on ventilators significantly longer (p = 0.049) and required longer treatment with corticosteroids (p = 0.045).

CONCLUSION

Identifying variants of the IL1Β gene can be used as a predictive tool for assessing the severity of COVID-19 pneumonia and tailoring personalized treatment strategies. Further research with a larger patient cohort is required to validate these findings.

Modulation in serum and hematological parameters as a prognostic indicator of COVID-19 infection in hypertension, diabetes mellitus, and different cardiovascular diseases

SARS-CoV-2 infection affects and modulates serum as well as hematological parameters. However, whether it modifies these parameters in the existing disease conditions, which help in the erection of specific treatments for the disease, is under investigation. Here, we aimed to determine whether serum and hematological parameters alteration in various diseases, diabetes mellitus (DM), hypertension (HTN), ischemic heart disease (IHD) and myocardial infarction (MI) conditions correlate and signal SARS-CoV-2 infection, which could be used as a rapid diagnosis tool for SARS-CoV-2 infection in disease conditions. To assess the projected goals, we collected blood samples of 1,113 male and female patients with solo and multiple disease conditions of DM/HTN/IHD/MI with severe COVID-19, followed by biochemical analysis, including COVID-19 virus detection by RT-qPCR. Furthermore, blood was collected from age-matched disease and healthy individuals 502 and 660 and considered as negative control. In our results, we examined higher levels of serum parameters, including D-dimer, ferritin, hs-CRP, and LDH, as well as hematological parameters, including TLC in sole and multiple diseases (DM/HTN/IHD/MI) conditions compared to the control subjects. Besides, the hematological parameters, including Hb, RBC, and platelet levels, decreased in the patients. In addition, we found declined levels of leukocyte count (%), lymphocyte (%), monocyte (%), and eosinophil (%), and elevated level of neutrophil levels (%) in all the disease patients infected with SARS-CoV-2. Besides, NLR and NMR ratios were also statistically significantly (p < 0.05) high in the patients with solo and multiple disease conditions of DM/HTN/IHD/MI infected with the SARS-CoV-2 virus. In conclusion, rapid alteration of sera and hematological parameters are associated with SARS-CoV-2 infections, which could help signal COVID-19 in respective disease patients. Moreover, our results may help to improve the clinical management for the rapid diagnosis of COVID-19 concurrent with respective diseases.

Peripheral blood indicators and COVID-19: an observational and bidirectional Mendelian randomization study

Blood is critical for health, supporting key functions like immunity and oxygen transport. While studies have found links between common blood clinical indicators and COVID-19, they cannot provide causal inference due to residual confounding and reverse causality. To identify indicators affecting COVID-19, we analyzed clinical data (n = 2,293, aged 18-65 years) from Guangzhou Medical University's first affiliated hospital (2022-present), identifying 34 significant indicators differentiating COVID-19 patients from healthy controls. Utilizing bidirectional Mendelian randomization analyses, integrating data from over 2.46 million participants from various large-scale studies, we established causal links for six blood indicators with COVID-19 risk, five of which is consistent with our observational findings. Specifically, elevated Troponin I and Platelet Distribution Width levels are linked with increased COVID-19 susceptibility, whereas higher Hematocrit, Hemoglobin, and Neutrophil counts confer a protective effect. Reverse MR analysis confirmed four blood biomarkers influenced by COVID-19, aligning with our observational data for three of them. Notably, COVID-19 exhibited a positive causal relationship with Troponin I (Tnl) and Serum Amyloid Protein A, while a negative association was observed with Plateletcrit. These findings may help identify high-risk individuals and provide further direction on the management of COVID-19.

Evaluation of hematological changes and immune response biomarkers as a prognostic factor in critical patients with COVID-19

COVID-19 disease has been a challenge for health systems worldwide due to its high transmissibility, morbidity, and mortality. Severe COVID-19 is associated with an imbalance in the immune response, resulting in a cytokine storm and a hyperinflammation state. While hematological parameters correlate with prognosis in COVID patients, their predictive value has not been evaluated specifically among those severely ill. Therefore, we aim to evaluate the role of hematological and immune response biomarkers as a prognostic factor in critically ill patients with COVID-19 admitted to the intensive care unit. From May 2020 to July 2021, a retrospective cohort study was conducted in a reference hospital in Manaus, which belongs to the Brazilian public health system. This study was carried out as single-center research. Clinical and laboratory parameters were analyzed to evaluate the association with mortality. We also evaluated the role of neutrophil-to-lymphocyte ratio (NLR), lymphocyte-to-monocyte ratio (LMR), platelet-to-lymphocyte ratio (PLR), and C-reactive protein-to-lymphocyte ratio (CLR). We gathered information from medical records, as well as from prescriptions and forms authorizing the use of antimicrobial medications. During the study period, 177 patients were included, with a mean age of 62.58 ± 14.39 years. The overall mortality rate was 61.6%. Age, mechanical ventilation (MV) requirement, leukocytosis, neutrophilia, high c-reactive protein level, NLR, and CLR showed a statistically significant association with mortality in the univariate analysis. In the multivariate logistic regression analysis, only MV (OR 35.687, 95% CI: 11.084-114.898, p< 0.001) and NLR (OR 1.026, 95% CI: 1.003-1.050, p = 0.028) remained statistically associated with the outcome of death (AUC = 0.8096). While the need for mechanical ventilation is a parameter observed throughout the hospital stay, the initial NLR can be a primary risk stratification tool to establish priorities and timely clinical intervention in patients with severe COVID-19 admitted to the ICU.

Morphological abnormalities of peripheral blood cells among patients with COVID-19 disease

Purpose

The hematological changes in COVID-19 patients continue to receive great attention, especially in the field of public health. To our knowledge, coronavirus disease may be identified based on the severity of illness, and the study of peripheral blood smears may offer important information to facilitate the identification. Thus, we evaluated the morphological abnormalities (atypical and immature lymphocytes, lymphocytes with micronuclei, various nuclear abnormalities among erythrocytes) and quantitative changes in peripheral blood cells among 48 individuals with COVID-19 disease.

Methods

The present study is a retrospective analysis of 48 individuals, including 24 hospitalized patients diagnosed with COVID-19 disease. The blood smears of all patients were subjected to a hematological examination to identify various morphological abnormalities in white and red blood cells. In addition, a micronucleus test was conducted to assess the incidence of chromosomal damage in lymphocytes. Furthermore, the complete blood count (CBC) was performed to evaluate changes in peripheral blood cells, particularly the differential total leukocyte count, which could indicate the immune response against viral infection in COVID-19 patients.

Results

The findings of the hematological study conducted on patients diagnosed with COVID-19 disease revealed neutrophilia, eosinophilia, mild monocytosis, decreased hematocrit level, elevated erythrocyte sedimentation rate (ESR), and immature leukocytes. It was observed that patients who were infected with coronavirus demonstrated mild thrombocytopenia. Furthermore, the micronucleus test indicated the presence of immature cells with micronuclei among lymphocytes and numerous nuclear abnormalities in red blood cells. These results help to shed light on the hematological changes that occur in COVID-19 patients, and could potentially contribute to the development of more effective treatments for the disease.

Conclusions

The examination of complete blood counts (CBCs) in conjunction with peripheral blood smears offers a potential means of identifying the impact of SARS-CoV-2 infection on the hematopoietic and immune systems, thereby providing early indications of inflammation. Based on a study, it has been suggested that SARS-CoV-2 may affect red and white blood cells causing morphological alterations thereby establishing a corresponding relationship with disease severity.

Cell free ACE2 RNA: A potential biomarker of COVID-19 severity

Despite the downward trend of COVID-19 pandemic and increased immunity of the general population, COVID-19 is still an elusive disease with risks due to emerging variants. Fast and reliable diagnosis of COVID-19 disease would allow better therapeutic interventions for patients at risk to develop more severe outcomes. Cell-free RNAs (cfRNAs) have been proven to be an effective biomarker in cancer and infectious diseases. It has been reported that cfRNAs are amplified in the bloodstream of these patients and at earlier stages of the disease, reflecting tissue damage. Hence, we hypothesize that cfRNAs may serve as a potential indicator of COVID-19 disease severity. To our knowledge, this is the first report to display a significant link between COVID-19 severity and cfRNA of angiotensin converting enzyme-2 (ACE2), the receptor for SARS-CoV-2 virus. qRT-PCR analysis of liquid biopsies from COVID-19 patients (n = 82) displayed a significant increase in ACE2-cfRNA levels in patients with severe manifestations. This finding correlated with blood biomarkers (ANC, WBC, and Creatinine) that were also significantly increased in these patients. We previously showed that bronchial cells from obese subjects express higher ACE2 levels, hence, we further analysed the involvement of obesity as a main contributor to severe outcomes. We confirm a significant increase of ACE2-cfRNA in the plasma of obese/overweight (Ob/Ov) COVID-19 patients compared to lean subjects, with no observed significant change in blood biomarkers. These findings suggest that monitoring ACE2-cfRNAs, as a biomarker, during COVID-19 infection may allow for better disease management, specifically for severe-COVID-19 patients.

Differences in leucocytes and inflammation-based indices among critically ill patients owing to SARS-CoV-2 variants during several successive waves of COVID-19 pandemic

BACKGROUND/AIM

Inflammatory indices are useful informative markers in assessing the severity of the COVID-19 disease course; however, their involvements during series waves of SARS-CoV-2 virus outbreaks in critical patients with COVID-19 remain unclear. Hence, we aimed to ascertain the changing dynamics of the combined inflammatory indices (NLR, dNLR, CLR, LMR, PLR, SII, and SIRI) and their associations with clinical outcomes in severe COVID-19 patients during serial waves of SARS-CoV-2.

PATIENTS AND METHODS

We retrospectively enrolled 163 severe COVID-19 patients admitted to the ICU during six SARS-CoV-2 waves.

RESULTS

We found that most of patients admitted to the ICU were from the fourth wave. Patients in the fourth wave were considerably younger and had the highest percentage of ARDS than other waves. The highest CRP was found in the first wave, while the lowest in patients admitted in the sixth wave. Although most of the COVID-19 waves were marked with leukocytosis, neutrophilia, and lymphocytopenia, the lowest of both NLR and dNLR were found in the fourth wave "Delta wave" and the lowest of both CLR and SII were observed in "Omicron wave". Interestingly, during most of the COVID-19 waves, the derived combined inflammatory ratio NLR, dNLR, CLR, SII and SIRI were sustained at high levels in fatal cases at the last day of hospitalization, while these indices declined in the alive group at the end of ICU hospitalization. No major difference was identified in lymphocyte count between admission and the last day of hospitalization in both deceased and recovered COVID-19 patients during Delta and Omicron waves. Moreover, patients admitted in the Omicron wave had less severe disease compared to those admitted in the Delta wave. The Kaplan-Meier analysis revealed no significant difference in survival rates or the probability of respiratory failure between six successive COVID-19 waves.

CONCLUSION

Taken together, our results showed marked differences in the alteration of nonspecific inflammation and damage in the adaptive immune response during the six serial SARS-CoV-2 waves. Considering the inflammatory response of infectious diseases, embedding inflammatory indices informative markers into routine clinical testing offers the potential to mitigate the impact of future pandemics of COVID-19 and other infectious diseases.

Time-Resolved Fluorescence Spectroscopy of Blood, Plasma and Albumin as a Potential Diagnostic Tool for Acute Inflammation in COVID-19 Pneumonia Patients

Fluorescence lifetime measurements of blood or plasma offer valuable insights into the microenvironment and molecular interactions of fluorophores, particularly concerning albumin. Neutrophil- and hypoxia-induced oxidative stress in COVID-19 pneumonia patients leads to hyperinflammation, various oxidative modifications of blood proteins, and potential alterations in the fluorescence lifetime of tryptophan-containing proteins, especially albumin. The objective of this study was to investigate the efficacy of time-resolved fluorescence spectroscopy of blood and plasma as a prompt diagnostic tool for the early diagnosis and severity assessment of COVID-19-associated pneumonia. This study examined a cohort of sixty COVID-19 patients with respiratory symptoms. To investigate whether oxidative stress is the underlying cause of the change in fluorescence lifetime, human serum albumin was treated with chloramine T. The time-resolved spectrometer Life Spec II (Edinburgh Instruments Ltd., Livingston, UK), equipped with a sub-nanosecond pulsed 280 nm diode, was used to measure the fluorescence lifetime of blood and plasma. The findings revealed a significant reduction in the fluorescence lifetime of blood (diluted 200 times) and plasma (diluted 20 times) at 360 nm in COVID-19 pneumonia patients compared with their respective values recorded six months post-infection and those of healthy individuals. Significant negative correlations were observed between the mean fluorescence lifetime of blood and plasma at 360 nm and several severity biomarkers and advanced oxidation protein products, while a positive correlation was found with albumin and the albumin-globulin ratio. The time-resolved fluorescence spectroscopy method demonstrates the potential to be used as a preliminary screening technique for identifying patients who are at risk of developing severe complications. Furthermore, the small amount of blood required for the measurements has the potential to enable a rapid fingerstick blood test.

Aggregate index of systemic inflammation (AISI) in admission as a reliable predictor of mortality in COPD patients with COVID-19

BACKGROUND

The role of leukocytes and systemic inflammation indicators in predicting the severity and mortality of inflammatory diseases has been well reported, such as the neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), monocyte to lymphocyte ratio (MLR), neutrophil/lymphocyte*platelet ratio (NLPR), derived neutrophil/lymphocyte ratio (dNLR), aggregate index of systemic inflammation (AISI), as well as systemic inflammation response index (SIRI) and systemic inflammation index (SII). The purpose of the present study was to investigate the prognostic role of systemic inflammatory indicators in the mortality of chronic obstructive pulmonary disease (COPD) patients with COVID-19.

METHODS

This retrospective study included 169 COPD patients hospitalized with COVID-19. Demographic, clinical, and laboratory data were obtained from the patients' electronic records. The ability of systemic inflammation indeces to distinguish the severity of COVID-19 was determined by receiver operating characteristic (ROC) analysis, and survival probability was determined by the mean of Kaplan-Meier curves, with the endpoint being death.

RESULTS

ROC curves showed that the AUD level was significant for WBC, MLR, SIRI, and AISI. Interestingly, Kaplan-Meier survival curves revealed that survival was lower with higher MLR (HR = 2.022, 95% CI = 1.030 to 3.968, P < 0.05) and AISI (HR = 2.010, 95% CI = 1.048 to 3.855, P < 0.05) values. However, the multivariate Cox regression model showed that only AISI was significantly associated with survival.

CONCLUSION

AISI in COPD patients with COVID-19 was a reliable predictor of mortality.

Adverse Hematological Effects of COVID-19 Vaccination and Pathomechanisms of Low Acquired Immunity in Patients with Hematological Malignancies

The SARS-CoV-2 virus and the COVID-19 pandemic have spread across the world and severely impacted patients living with hematological conditions. Immunocompromised patients experience rapidly progressing symptoms following COVID-19 infection and are at high risk of death. In efforts to protect the vulnerable population, vaccination efforts have increased exponentially in the past 2 years. Although COVID-19 vaccination is safe and effective, mild to moderate side effects such as headache, fatigue, and soreness at the injection site have been reported. In addition, there are reports of rare side effects, including anaphylaxis, thrombosis with thrombocytopenia syndrome, Guillain-Barré Syndrome, myocarditis, and pericarditis after vaccination. Further, hematological abnormalities and a very low and transient response in patients with hematological conditions after vaccination raise concerns. The objective of this review is to first briefly discuss the hematological adverse effects associated with COVID-19 infection in general populations followed by critically analyzing the side effects and pathomechanisms of COVID-19 vaccination in immunocompromised patients with hematological and solid malignancies. We reviewed the published literature, with a focus on hematological abnormalities associated with COVID-19 infection followed by the hematological side effects of COVID-19 vaccination, and the mechanisms by which complications can occur. We extend this discussion to include the viability of vaccination efforts within immune-compromised patients. The primary aim is to provide clinicians with critical hematologic information on COVID-19 vaccination so that they can make informed decisions on how to protect their at-risk patients. The secondary goal is to clarify the adverse hematological effects associated with infection and vaccination within the general population to support continued vaccination within this group. There is a clear need to protect patients with hematological conditions from infection and modulate vaccine programs and procedures for these patients.

SARS-CoV-2 Lysate Stimulation Impairs the Release of Platelet-like Particles and Megakaryopoiesis in the MEG-01 Cell Line

SARS-CoV-2 infection causes a considerable inflammatory response coupled with impaired platelet reactivity, which can lead to platelet disorders recognized as negative prognostic factors in COVID-19 patients. The virus may cause thrombocytopenia or thrombocytosis during the different disease stages by destroying or activating platelets and influencing platelet production. While it is known that several viruses can impair megakaryopoiesis by generating an improper production and activation of platelets, the potential involvement of SARS-CoV-2 in affecting megakaryopoiesis is poorly understood. To this purpose, we explored, in vitro, the impact of SARS-CoV-2 stimulation in the MEG-01 cell line, a human megakaryoblastic leukemia cell line, considering its spontaneous capacity of releasing platelet-like particles (PLPs). We interrogated the effect of heat-inactivated SARS-CoV-2 lysate in the release of PLPs and activation from MEG-01, the signaling pathway influenced by SARS-CoV-2, and the functional effect on macrophagic skewing. The results highlight the potential influence of SARS-CoV-2 in the early stages of megakaryopoiesis by enhancing the production and activation of platelets, very likely due to the impairment of STATs signaling and AMPK activity. Overall, these findings provide new insight into the role of SARS-CoV-2 in affecting megakaryocyte-platelet compartment, possibly unlocking another avenue by which SARS-CoV-2 moves.

Reduced IFN-γ levels along with changes in hematologic and immunologic parameters are key to COVID-19 severity in Bangladeshi patients

The manifestation of coronavirus disease 2019 (COVID-19) severity and mortality has been associated with dysregulation of the immune response, often influenced by racial disparities and conferred by changes in hematologic and immunologic parameters. These biological and hematologic parameters as well as cytokine profiles were investigated in a cohort of 61 COVID-19-positive patients (categorized into mild, moderate, and severe groups) from Bangladesh using standard analytical methods. The data reported that the interleukin (IL)-4 and IL-6 levels were significantly increased, whereas the levels of interferon (IFN)-γ were significantly reduced in patients with severe COVID-19 (p < 0.05) compared with those in patients with mild and/or moderate COVID-19. The extent of erythrocyte sedimentation rate (ESR); neutrophil count; and levels of ferritin, C-reactive protein (CRP), and D-dimer (p < 0.05) were found to be significantly increased, whereas the white blood cell (WBC), lymphocyte, eosinophil, and platelet counts (p < 0.05) were observed to be significantly reduced in patients with severe COVID-19 compared with those in the patients in other 2 groups. Our study exhibited a significantly higher IL-6-to-lymphocyte ratio in patients with severe COVID-19 than in those with mild and moderate COVID-19. The calculated neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR), and ferritin-to-ESR ratio were significantly increased in patients with severe COVID-19. The increase in the IL-4 and IL-6 levels along with CRP and D-dimer levels may envisage a hyperinflammatory environment and immune dysregulation, which contribute to prolonged viral persistence, leading to severe disease. However, the reduced level of IFN-γ can be attributed to a less fatality toll in Bangladesh compared with that in the rest of the world.

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.

Interleukin-1β and Interleukin-10 Profiles and Ratio in Serum of COVID-19 Patients and Correlation with COVID-19 Severity: A Time Series Study

BACKGROUND

Coronavirus disease-19 (COVID-19) can, in severe cases, lead to cytokine-release syndrome owing to an excessive immune response. The release of different cytokines aggravates disease severity. IL-1β is a pro-inflammatory cytokine, while IL-10 is an anti-inflammatory cytokine, and both are involved in the human immune response to infection. This study aimed to determine whether serum levels of IL-1β and IL-10 and the ratio of the two over time in patients with COVID-19 could facilitate early identification of disease severity.

METHODS

An analytical, observational time-series design was employed. Fifty participants were enrolled between May and October 2020 and were divided into two groups-non-severe (n = 20), and severe (n = 30). IL-1β and IL-10 were analyzed using BD cytometric bead array sets. Association of the IL-1β:IL-10 ratio with COVID-19 severity was analyzed using a Mann-Whitney test and Fisher's exact test. Optimal cut-off values to predict disease severity were determined by Youden's index.

RESULTS

In non-severe and severe groups, the median serum levels of IL-1β decreased on day 3 (1.72 ng/mL and 2.10 ng/mL, respectively), then increased on day 6 (2.05 ng/mL and 3.31 ng/mL, respectively). However, the median of IL-10 increased on day 3 (1.88 ng/mL and 2.30 ng/mL, respectively) and day 6 (2.02 ng/mL and 2.39 ng/mL, respectively). There was no significant association between the IL-1β:IL-10 ratio and COVID-19 severity at any time-point (p>0.05). The cutoff value of serum IL-10 between the two groups on days 0, 3, and 6 was 1.09 pg/mL (sensitivity: 66.6%; PPV: 71.4%), 2.11 pg/mL (sensitivity: 67.7%; PPV: 50.0%), and 2.08 pg/mL (sensitivity: 78.6%; PPV: 70.9%), respectively.

CONCLUSION

The IL-1β:IL-10 ratio was not correlated to COVID-19 severity. However, owing to its high sensitivity, IL-10 may be a potential biomarker for disease severity in severe COVID-19.

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.

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'.

Can Lung Imaging Scores and Clinical Variables Predict Severe Course and Fatal Outcome in COVID-19 Pneumonia Patients? A Single-Center Observational Study

COVID-19 prediction models mostly consist of combined clinical features, laboratory parameters, and, less often, chest X-ray (CXR) findings. Our main goal was to propose a prediction model involving imaging methods, specifically ultrasound. This was a single-center, retrospective cohort observational study of patients admitted to the University Hospital Split from November 2020 to May 2021. Imaging protocols were based on the assessment of 14 lung zones for both lung ultrasound (LUS) and computed tomography (CT), correlated to a CXR score assessing 6 lung zones. Prediction models for the necessity of mechanical ventilation (MV) or a lethal outcome were developed by combining imaging, biometric, and biochemical parameters. A total of 255 patients with COVID-19 pneumonia were included in the study. Four independent predictors were added to the regression model for the necessity of MV: LUS score, day of the illness, leukocyte count, and cardiovascular disease (χ2 = 29.16, p < 0.001). The model accurately classified 89.9% of cases. For the lethal outcome, only two independent predictors contributed to the regression model: LUS score and patient’s age (χ2 = 48.56, p < 0.001, 93.2% correctly classified). The predictive model identified four key parameters at patient admission which could predict an adverse outcome.

Evaluation of individual and combined NLR, LMR and CLR ratio for prognosis disease severity and outcomes in patients with COVID-19

Object

The study aimed to utilize the peripheral blood immunological parameters and resulting individual and combined inflammatory indices [neutrophil/lymphocyte ratio (NLR), lymphocyte/monocyte ratio (LMR) and C-reactive protein/lymphocyte ratio (CLR)] in predicting the prognosis and mortality in COVID-19 patients.

Materials and methods

The measurements of individual and combined inflammatory indices (NLR, LMR and CLR) were performed at hospital admission and at last day of hospitalization for COVID-19 patients.

Results

Prominent elevation of NLR and CLR among patients with refractory disease admitted to Intensive Care Unit (ICU) and deceased patients was found when compared with moderate ill patients and healthy controls. Interestingly, NLR and CLR typically returned to near normal value as patients recover from severe infection. By contrast, deceased patients had persistent increased NLR and CLR until last day of hospitalization in ICU. ROC obtained for the above parameters showed that NLR and CLR were the most associated immunological parameters with the severity of COVID-19 disease. Using multivariate logistic regression analysis, CLR > 69.46 is an independent prognostic factors in identifying critically ill COVID-19 cases. Study of the combined markers NLR and CLR showed that most of patients admitted in ICU were characterized with high NLR combined with high CLR, while most of healthy subjects and non-ICU group have low NLR combined with low CLR.

Conclusion

The combination of NLR and CLR could improve the predictive efficacy compared to individual markers to segregate patients who will develop a severe disease from those with a mild pathology.

Significance of Immune Status of SARS-CoV-2 Infected Patients in Determining the Efficacy of Therapeutic Interventions

Coronavirus disease 2019 (COVID-19) is now being investigated for its distinctive patterns in the course of disease development which can be indicated with miscellaneous immune responses in infected individuals. Besides this series of investigations on the pathophysiology of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), significant fundamental immunological and physiological processes are indispensable to address clinical markers of COVID-19 disease and essential to identify or design effective therapeutics. Recent developments in the literature suggest that deficiency of type I interferon (IFN) in serum samples can be used to represent a severe progression of COVID-19 disease and can be used as the basis to develop combined immunotherapeutic strategies. Precise control over inflammatory response is a significant aspect of targeting viral infections. This account presents a brief review of the pathophysiological characteristics of the SARS-CoV-2 virus and the understanding of the immune status of infected patients. We further discuss the immune system’s interaction with the SARS-CoV-2 virus and their subsequent involvement of dysfunctional immune responses during the progression of the disease. Finally, we highlight some of the implications of the different approaches applicable in developing promising therapeutic interventions that redirect immunoregulation and viral infection.