Effects of severe acute respiratory syndrome (SARS) coronavirus infection on peripheral blood lymphocytes and their subsets

Clinical features and predictors for patients with severe SARS-CoV-2 pneumonia at the start of the pandemic: a retrospective multicenter cohort study

Background

This study was performed to investigate clinical features of patients with severe SARS-CoV-2 pneumonia and identify risk factors for converting to severe cases in those who had mild to moderate diseases at the start of the pandemic in China.

Methods

In this retrospective, multicenter cohort study, patients with mild to moderate SARS-CoV-2 pneumonia were included. Demographic data, symptoms, laboratory values, and clinical outcomes were collected. Data were compared between non-severe and severe patients.

Results

58 patients were included in the final analysis. Compared with non-severe cases, severe patients with SARS-CoV-2 pneumonia had a longer: time to clinical recovery (12·9 ± 4·4 vs 8·3 ± 4·7; P = 0·0011), duration of viral shedding (15·7 ± 6·7 vs 11·8 ± 5·0; P = 0·0183), and hospital stay (20·7 ± 1·2 vs 14·4 ± 4·3; P = 0·0211). Multivariate logistic regression indicated that lymphocyte count was significantly associated with the rate of converting to severe cases (odds ratio 1·28, 95%CI 1·06–1·54, per 0·1 ×  10⁹/L reduced; P = 0·007), while using of low-to-moderate doses of systematic corticosteroids was associated with reduced likelihood of converting to a severe case (odds ratio 0·14, 95%CI 0·02–0·80; P = 0·0275).

Conclusions

The low peripheral blood lymphocyte count was an independent risk factor for SARS-CoV-2 pneumonia patients converting to severe cases. However, this study was carried out right after the start of the pandemic with small sample size. Further prospective studies are warranted to confirm these findings.

Trial registration

Chinese Clinical Trial Registry, ChiCTR2000029839. Registered 15 February 2020 - Retrospectively registered.

Monocyte-driven atypical cytokine storm and aberrant neutrophil activation as key mediators of COVID-19 disease severity

Epidemiological and clinical reports indicate that SARS-CoV-2 virulence hinges upon the triggering of an aberrant host immune response, more so than on direct virus-induced cellular damage. To elucidate the immunopathology underlying COVID-19 severity, we perform cytokine and multiplex immune profiling in COVID-19 patients. We show that hypercytokinemia in COVID-19 differs from the interferon-gamma-driven cytokine storm in macrophage activation syndrome, and is more pronounced in critical versus mild-moderate COVID-19. Systems modelling of cytokine levels paired with deep-immune profiling shows that classical monocytes drive this hyper-inflammatory phenotype and that a reduction in T-lymphocytes correlates with disease severity, with CD8+ cells being disproportionately affected. Antigen presenting machinery expression is also reduced in critical disease. Furthermore, we report that neutrophils contribute to disease severity and local tissue damage by amplification of hypercytokinemia and the formation of neutrophil extracellular traps. Together our findings suggest a myeloid-driven immunopathology, in which hyperactivated neutrophils and an ineffective adaptive immune system act as mediators of COVID-19 disease severity.

Peripheral T cell lymphopenia in COVID-19: potential mechanisms and impact

Immunopathogenesis involving T lymphocytes, which play a key role in defence against viral infection, could contribute to the spectrum of COVID-19 disease and provide an avenue for treatment. To address this question, a review of clinical observational studies and autopsy data in English and Chinese languages was conducted with a search of registered clinical trials. Peripheral lymphopenia affecting CD4 and CD8 T cells was a striking feature of severe COVID-19 compared with non-severe disease. Autopsy data demonstrated infiltration of T cells into organs, particularly the lung. Seventy-four clinical trials are on-going that could target T cell-related pathogenesis, particularly IL-6 pathways. SARS-CoV-2 infection interrupts T cell circulation in patients with severe COVID-19. This could be due to redistribution of T cells into infected organs, activation induced exhaustion, apoptosis, or pyroptosis. Measuring T cell dynamics during COVID-19 will inform clinical risk-stratification of hospitalised patients and could identify those who would benefit most from treatments that target T cells.

Eosinopenia is a reliable marker of severe disease and unfavourable outcome in patients with COVID-19 pneumonia

BACKGROUND AND AIM

Viral pneumonia is the most relevant clinical presentation of COVID-19 which may lead to severe acute respiratory syndrome and even death. Eosinopenia was often noticed in patients with COVID-19 pneumonia, but its role is poorly investigated. The aim of the present study was to investigate the characteristics and clinical outcomes of patients with COVID-19 pneumonia and eosinopenia.

METHODS

We revised the records of consecutive patients with COVID-19 pneumonia admitted to our ER-COVID-19 area in order to compare clinical characteristics and outcomes of patients with and without eosinopenia. We considered the following clinical outcomes: 4-weeks survival; need for intensive respiratory support; and hospital discharge.

RESULTS

Out of first 107 consecutive patients with pneumonia and a positive COVID-19 nasopharyngeal swab, 75 patients showed undetectable eosinophil count (absolute eosinopenia). At 4 weeks, 38 patients (38.4%) had required intensive respiratory treatment, 25 (23.4%) deceased and 42 (39.2%) were discharged. Compared with patients without absolute eosinopenia, patients with absolute eosinopenia showed higher need of intensive respiratory treatment (49.3% vs 13.3%, P < .001), higher mortality (30.6% vs 6.2%, P .006) and lower rate of hospital discharge (28% vs 65.6%, P < .001). Binary logistic regression analyses including neutrophil, lymphocyte, eosinophil, basophil and monocyte counts showed that absolute eosinopenia was an independent factor associated with 4-weeks mortality, need for intensive respiratory support and hospital discharge.

CONCLUSIONS

Absolute eosinopenia is associated with clinical outcomes in patients with COVID-19 pneumonia and might be used as a marker to discriminate patients with unfavourable prognosis.

What do we know about IL-6 in COVID-19 so far?

Interleukin 6 (IL-6) is a cytokine with dual functions of pro-inflammation and anti-inflammation. It is mainly produced by mononuclear macrophages, Th2 cells, vascular endothelial cells and fibroblasts. IL-6 binds to glycoprotein 130 and one of these two receptors, membrane-bound IL-6R or soluble IL-6R, forming hexamer (IL-6/IL-6R/gp130), which then activates different signaling pathways (classical pathway, trans-signaling pathway) to exert dual immune-modulatory effects of anti-inflammation or pro-inflammation. Abnormal levels of IL-6 can cause multiple pathological reactions, including cytokine storm. Related clinical studies have found that IL-6 levels in severe COVID-19 patients were much higher than in healthy population. A large number of studies have shown that IL-6 can trigger a downstream cytokine storm in patients with COVID-19, resulting in lung damages, aggravating clinical symptoms and developing excessive inflammation and acute respiratory distress syndrome (ARDS). Monoclonal antibodies against IL-6 or IL-6R, such as tocilizumab, sarilumab, siltuximab and olokizumab may serve as therapeutic options for COVID-19 infection.

Lymphocytes screening on admission is essential for predicting in-hospital clinical outcome in COVID-19 patients: A retrospective cohort study

Introduction

We aimed to identify the associations between the lymphocytes (LYM) absolute count on admission and clinical outcomes in COVID‐19 patients.

Methods

In this retrospective study, 224 COVID‐19 patients who were admitted to General Hospital of Central Theater Command of the PLA from January 22 to April 4, 2020, were consecutively included. These patients were divided into the lymphopenia group and the nonlymphopenia group according to whether the LYM count on admission was below the normal range.

Results

During hospitalization, patients in the lymphopenia group have a much higher all‐cause mortality (14.5% vs 0.0%; P < .001) and an evidently longer length of hospital stay (24.0 vs 17.5 days; P < .001) than patients in the nonlymphopenia group. The correlation analysis results indicated that the LYM count was negatively correlated with the values of NEU (R = −.2886, P < .001), PT (R = −.2312, P < .001), FIB (R = −.2954, P < .001), D‐D (R = −.3554, P < .001), CRP (R = −.4899, P < .001), IL‐6 (R = −.5459, P < .001), AST (R = −.2044, P < .01), Cr (R = −.1350, P < .05), CPK (R = −.2119, P < .01), CK‐Mb (R = −.1760, P < .01), and LDH (R = −.4330, P < .001), and was positively correlated with the count of PLT (R = .2679, P < .001). In addition, LYM as a continuous variable was associated with 97% decreased risk of in‐hospital mortality in the fully adjusted models (OR = 0.03, 95%CI, 0.00‐0.37, P < .001).

Discussion

LYM screening on admission is a critical predictor for assessment of disease severity and clinical outcomes in patients with COVID‐19, and lymphopenia substantially correlates with poor clinical outcomes.

Immunological Approaches to the Treatment of New Coronavirus Infection (Review)

The pandemic of the new coronavirus infection (COVID-19) caused by the SARS-CoV-2 virus has spread all over the world. The large amount of information that appears every day requires comprehension and systematization. The immunological aspects of the virus-host interaction are the core issues in the effective treatment and prevention of COVID-19' development. The review analyzes the known pathways of the viral invasion and evasion, the mechanisms of the cytokine storm, endothelial damage, and hypercoagulability associated with SARS-CoV-2 infection. Clinical data from previous SARS and MERS epidemics is discussed here. We also address the therapeutic approaches based on the basic knowledge of immune response and the blood cells' immune functions, as well as the ways to reduce their hyperactivation. The use of interferon therapy, anti-inflammatory therapy, anti-cytokine therapy, neutralizing antibodies, convalescent plasma, and mesenchymal stem cells, as well as prophylactic vaccines, is discussed.

Risk factors for mortality in critically ill patients with COVID-19: a multicenter retrospective case-control study

BACKGROUND

Coronavirus disease 2019 (COVID-19) has spread around the world, until now, the number of positive and death cases is still increasing. Therefore, it remains important to identify risk factors for death in critically patients.

METHODS

We collected demographic and clinical data on all severe inpatients with COVID-19. We used univariable and multivariable Cox regression methods to determine the independent risk factors related to likelihood of 28-day and 60-day survival, performing survival curve analysis.

RESULTS

Of 325 patients enrolled in the study, Multi-factor Cox analysis showed increasing odds of in-hospital death associated with basic illness (hazard ratio [HR] 6.455, 95% Confidence Interval [CI] 1.658-25.139, P = 0.007), lymphopenia (HR 0.373, 95% CI 0.148-0.944, P = 0.037), higher Sequential Organ Failure Assessment (SOFA) score on admission (HR 1.171, 95% CI 1.013-1.354, P = 0.033) and being critically ill (HR 0.191, 95% CI 0.053-0.687, P = 0.011). Increasing 28-day and 60-day mortality, declining survival time and more serious inflammation and organ failure were associated with lymphocyte count < 0.8 × 109/L, SOFA score > 3, Acute Physiology and Chronic Health Evaluation II (APACHE II) score > 7, PaO2/FiO2 < 200 mmHg, IL-6 > 120 pg/ml, and CRP > 52 mg/L.

CONCLUSIONS

Being critically ill and lymphocyte count, SOFA score, APACHE II score, PaO2/FiO2, IL-6, and CRP on admission were associated with poor prognosis in COVID-19 patients.

Impact of age and gender on lymphocyte subset counts in patients with COVID-19

In symptomatic patients with acute Coronavirus disease 2019 (COVID-19), lymphocytopenia is one of the most prominent laboratory findings. However, to date age and gender have not been considered in assessment of COVID-19-related cell count alterations. In this study, the impact of COVID-19 as well as age and gender on a large variety of lymphocyte subsets was analyzed in 33 COVID-19 patients and compared with cell counts in 50 healthy humans. We confirm that cell counts of total lymphocytes, B, NK, cytotoxic and helper T cells are reduced in patients with severe COVID-19, and this tendency was observed in patients with moderate COVID-19. Decreased cell counts were also found in all subsets of these cell types, except for CD4+ and CD8+ effector memory RA+ (EMRA) and terminal effector CD8+ cells. In multivariate analysis however, we show that in addition to COVID-19, there is an age-dependent reduction of total, central memory (CM), and early CD8+ cell subsets, as well as naïve, CM, and regulatory CD4+ cell subsets. Remarkably, reduced naïve CD8+ cell counts could be attributed to age alone, and not to COVID-19. By contrast, decreases in other subsets could be largely attributed to COVID-19, and only partly to age. In addition to COVID-19, male gender was a major factor influencing lower counts of CD3+ and CD4+ lymphocyte numbers. Our study confirms that cell counts of lymphocytes and their subsets are reduced in patients with COVID-19, but that age and gender must be considered when interpreting the altered cell counts.

Persistent symptoms and lab abnormalities in patients who recovered from COVID-19

With increasing numbers of patients recovering from COVID-19, there is increasing evidence for persistent symptoms and the need for follow-up studies. This retrospective study included patients without comorbidities, who recovered from COVID-19 and attended an outpatient clinic at a university hospital for follow-up care and potential convalescent plasma donation. Network analysis was applied to visualize symptom combinations and persistent symptoms. Comprehensive lab-testing was ascertained at each follow-up to analyze differences regarding patients with vs without persistent symptoms. 116 patients were included, age range was 18-69 years (median: 41) with follow-ups ranging from 22 to 102 days. The three most frequent persistent symptoms were Fatigue (54%), Dyspnea (29%) and Anosmia (25%). Lymphopenia was present in 13 of 112 (12%) cases. Five of 35 cases (14%) had Lymphopenia in the later follow-up range of 80-102 days. Serum IgA concentration was the only lab parameter with significant difference between patients with vs without persistent symptoms with reduced serum IgA concentrations in the patient cohort of persistent symptoms (p = 0.0219). Moreover, subgroup analyses showed that patients with lymphopenia experienced more frequently persistent symptoms. In conclusion, lymphopenia persisted in a noticeable percentage of recovered patients. Patients with persistent symptoms had significantly lower serum IgA levels. Furthermore, our data provides evidence that lymphopenia is associated with persistence of COVID-19 symptoms.

Baseline T-lymphocyte subset absolute counts can predict both outcome and severity in SARS-CoV-2 infected patients: a single center study

The aim of this study was to evaluate the role of baseline lymphocyte subset counts in predicting the outcome and severity of COVID-19 patients. Hospitalized patients confirmed to be infected with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) were included and classified according to in-hospital mortality (survivors/nonsurvivors) and the maximal oxygen support/ventilation supply required (nonsevere/severe). Demographics, clinical and laboratory data, and peripheral blood lymphocyte subsets were retrospectively analyzed. Overall, 160 patients were retrospectively included in the study. T-lymphocyte subset (total CD3+, CD3+ CD4+, CD3+ CD8+, CD3+ CD4+ CD8+ double positive [DP] and CD3+ CD4− CD8− double negative [DN]) absolute counts were decreased in nonsurvivors and in patients with severe disease compared to survivors and nonsevere patients (p < 0.001). Multivariable logistic regression analysis showed that absolute counts of CD3+ T-lymphocytes < 524 cells/µl, CD3+ CD4+ < 369 cells/µl, and the number of T-lymphocyte subsets below the cutoff (T-lymphocyte subset index [TLSI]) were independent predictors of in-hospital mortality. Baseline T-lymphocyte subset counts and TLSI were also predictive of disease severity (CD3+  < 733 cells/µl; CD3+ CD4+ < 426 cells/µl; CD3+ CD8+ < 262 cells/µl; CD3+ DP < 4.5 cells/µl; CD3+ DN < 18.5 cells/µl). The evaluation of peripheral T-lymphocyte absolute counts in the early stages of COVID-19 might represent a useful tool for identifying patients at increased risk of unfavorable outcomes.

The Many Faces of Innate Immunity in SARS-CoV-2 Infection

The innate immune system is important for initial antiviral response. SARS-CoV-2 can result in overactivity or suppression of the innate immune system. A dysregulated immune response is associated with poor outcomes; with patients having significant Neutrophil-to-Lymphocyte ratios (NLR) due to neutrophilia alongside lymphopenia. Elevated interleukin (IL)-6 and IL-8 leads to overactivity and is a prominent feature of severe COVID-19 patients. IL-6 can result in lymphopenia; where COVID-19 patients typically have significantly altered lymphocyte subsets. IL-8 attracts neutrophils; which may play a significant role in lung tissue damage with the formation of neutrophil extracellular traps leading to cytokine storm or acute respiratory distress syndrome. Several factors like pre-existing co-morbidities, genetic risks, viral pathogenicity, and therapeutic efficacy act as important modifiers of SARS-CoV-2 risks for disease through an interplay with innate host inflammatory responses. In this review, we discuss the role of the innate immune system at play with other important modifiers in SARS-CoV-2 infection.

Susceptibility to SARS-CoV-2 infection in patients undergoing chemotherapy and radiation therapy

The outbreak of the new coronavirus disease (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has rapidly become a public health emergency of international concern, especially affecting the elderly people and patients with chronic disease, such as hypertension and respiratory syndromes. Patients undergoing chemotherapy treatment (e.g., bleomycin, cyclophosphamide, methotrexate, monoclonal antibodies, and paclitaxel therapy) are vulnerable to the development of respiratory syndromes induced by chemotherapeutic agents and are also more susceptible to viral infections as they are immunosuppressed. Neutropenia is an important risk factor for increased vulnerability to infections, as a respiratory syndrome involves an array of immune cells maintaining the balance between pathogen clearance and immunopathology. However, the differential diagnosis of pulmonary symptoms in cancer patients is broad, with complications being related to the malignancy itself, treatment toxicity, and infections. The risk factors depend on the specific type of cancer, chemotherapy, patient characteristics, and comorbidities. Thus, this review discusses the main events implicated in immunosuppression caused by chemotherapy and radiation therapy and the association of immunosuppression and other factors with SARS-CoV-2 infection susceptibility in cancer patients; and, importantly, how to deal with this situation in face of the current pandemic scenario.

Hallmarks of immune response in COVID-19: Exploring dysregulation and exhaustion

One and half year following the occurrence of COVID-19 pandemic, significant efforts from laboratories all over the world generated a huge amount of data describing the prototypical features of immunity in the course of SARS-CoV-2 infection. In this Review, we rationalize and organize the main observations, trying to define a "core" signature of immunity in COVID-19. We identified six hallmarks describing the main alterations occurring in the early infection phase and in the course of the disease, which predispose to severe illness. The six hallmarks are dysregulated type I IFN activity, hyperinflammation, lymphopenia, lymphocyte impairment, dysregulated myeloid response, and heterogeneous adaptive immunity to SARS-CoV-2. Dysregulation and exhaustion came out as the trait d'union, connecting abnormalities affecting both innate and adaptive immunity, humoral and cellular responses.

The Course of COVID-19 in Four Patients with HIV During the Pandemic

BACKGROUND

The clinical spectrum of SARS-CoV-2 infection may vary from simple colds to a severe acute respiratory syndrome, metabolic acidosis, septic shock, and multiple organ failure. Current evidence indicates that the risk of severe illness increases with age, in the male sex, and with certain chronic medical problems. Many people living with HIV have other conditions that increase their risk. ; Case presentation: In the first 3 months of the pandemic, four patients with HIV were hospitalized in our clinic because of COVID-19. The disease severity was mild in two patients with normal CD4+ T count. However, one patient with a low CD4+T count died and the other developed retinal detachment one month after discharge. The deceased patient had a malignancy. ; Conclusion: In this study, the effect of the immunological status of the patients on the course of COVID-19 and the developing vascular complications was evaluated in 4 patients with HIV.

IL-6 and Other Biomarkers associated with Poor Prognosis in a Cohort of Hospitalized Patients with COVID-19 in Madrid

Objectives:

There are several published works on the prognostic value of biomarkers in relation to the severity or fatal outcome of coronavirus disease 2019 (COVID-19). In Spain, the second European country in incidence of the disease at the time of data collection, there are few studies that include both laboratory parameters and clinical parameters. Our aim is to study the relationship of a wide series of biomarkers with admission to intensive care and death in a hospital in the Autonomous Community of Madrid (Spain), with special attention to IL-6 due to its role in the systemic inflammatory response associated with a worse prognosis of the disease.

Methods:

Data were collected from 546 hospitalized patients with COVID-19. All of them had IL-6 results, in addition to other biochemical and haematological parameters. The difference of the medians for the selected parameters between the groups (ICU vs non-ICU, dead vs survivors) was studied using a Mann-Whitney analysis. The independent variables that predicted death were studied using a Cox proportional hazard regression model.

Results:

Higher age and blood concentrations of ALT, creatinine, CK, cTnI, LDH, NT-proBNP, CRP, IL-6, leucocyte count and D-dimer together with lower blood concentrations of albumin and lymphocyte count were associated with mortality in univariate analysis. Age, LDH, IL-6 and lymphocyte count remained associated with death in multivariate analysis.

Conclusions:

Age, LDH, IL-6 and lymphocyte count, as independent predictors of death, could be used to establish more aggressive therapies in COVID-19 patients.

Clinical Manifestations of COVID-19

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the third coronavirus causing an outbreak in the twenty-first century. It is related to a contagious coronavirus disease (COVID-19), which its high pace of spreading allowed it to lie to the whole world and be turned into a pandemic only a few months after the identification of the first case. Currently, the reverse transcription-polymerase chain reaction (RT-PCR) test of throat swap is the gold standard of diagnosis; however, several studies have reported false-negative results with non-ideal sensitivity. Because this pandemic constitutes a significant burden on global healthcare systems and due to the high transmission rate of the virus, an accurate diagnosis algorithm is needed to reduce the missing case number. A comprehensive clinical examination and taking a history of all systems (not just limited to the respiratory system) combined with hematologic laboratory tests and chest imaging can lead to a sensitive diagnosis, severity assessment, and RT-PCT test interpretation. This chapter focuses on clinical characteristics, hematologic laboratory, and chest imaging features in COVID-19.

From HIV to Coronavirus Disease 2019 (COVID-19): Hematologic Complications in Viral Pandemics

CONTEXT.—

From the onset of the human immunodeficiency virus (HIV) pandemic in the 1980s to the recent coronavirus disease 2019 (COVID-19) pandemic, multiple viral pandemics have occurred and all have been associated with hematologic complications of varying severity.

OBJECTIVE.—

To review the hematologic complications associated with the HIV and other viral pandemics, the current theories regarding their causation, and the incidence and clinical impact of these complications on infected patients.

DATA SOURCES.—

Peer-reviewed medical literature and the author's personal experience.

CONCLUSIONS.—

The HIV and other viral pandemics have been associated with a variety of hematologic complications that often cause significant morbidity and mortality in affected patients. HIV infection is associated with multiple hematologic disorders, many of which have a lower incidence in the era of highly active antiretroviral therapy but still represent a major clinical problem for HIV-infected patients. Our understanding of the pathogenesis of HIV-related hematologic complications, including HIV-associated lymphoproliferative disorders, has evolved in recent years. Other viral pandemics, including H1N1 influenza, severe acute respiratory syndrome (SARS) coronavirus, Middle East respiratory syndrome (MERS) coronavirus, and COVID-19, have also been associated with hematologic complications of varying severity. Our emerging understanding of the pathogenesis of the hematologic complications of HIV, COVID-19, and other viral pandemics may help in prevention, correct diagnosis, and treatment of these complications in current and future pandemics.

Is COVID-19 a Systemic Disease?

Background:

Many observations denote that we should deal with COVID-19 as a systemic disease.

Methods:

In the following report, we briefly discuss observations denoting “the systemic” nature of COVID-19.

Results:

COVID-19 virology, the roles of ACE-2 receptor in COVID-19 pathogenesis, immunological aspects of the disease, endothelial dysfunction and coagulopathy, and autopsy studies denote the systemic nature of COVID-19.

Conclusion:

Thinking of COVID-19 as a systemic disease, we will implement our ways of understanding and hence dealing with that disease. The most important public health solution is an effective vaccine for the broad population remaining at risk. As patients with COVID-19 present a broad spectrum of clinical presentation and distinct phenotypes, different strategies of management should be customized to the specific individual phenotypes. Further researches are highly needed to clarify the concept of “Is COVID-19 a systemic disease?”. Until that time, we think that clinicians should deal with COVID-19 as a systemic disease.

Impact of age to ferritin and neutrophil-lymphocyte ratio as biomarkers for intensive care requirement and mortality risk in COVID-19 patients in Makassar, Indonesia

Inflammation plays a substantial role in COVID-19 pathophysiology. Ferritin and neutrophil-lymphocyte ratio (NLR) are significant prognostic biomarkers used in COVID-19 patients, although they are affected by other factors such as comorbidities and age. Aging changes the immune system through immunosenescence and inflammaging; however, there are limited number of studies evaluating its effect on ferritin and NLR as part of the complete assessment for intensive care requirement and mortality risk. A single-center retrospective cohort study of 295 COVID-19 patients was performed at the Siloam Hospitals Makassar, South Sulawesi, Indonesia from April to August 2020. After admission, all patients were followed up for clinical outcomes. Patients were grouped into strata based on age (<50 years vs. ≥50 years) and risk groups (low-risk ferritin vs. high-risk ferritin; low-risk NLR vs. high-risk NLR). The endpoints of the study were the intensive care requirements and mortality. Among the 295 COVID-19 patients, 264 survived and 31 deceased. Ferritin and NLR had higher area under curve (AUC) values than other inflammatory parameters and had significantly different outcomes in both mortality and intensive care requirement groups. The combination of ferritin and NLR showed higher AUC values for intensive care requirement and mortality (AUC, 0.783; 95% confidence interval, 0.703-0.864). Multivariate analysis showed that both endpoints were strongly affected by age, ferritin level, and NLR. Age significantly multiplied clinical endpoints in low-risk group patients but not in high-risk group patients. The combination of ferritin and NLR had a better predictive value for intensive care requirement and mortality risk. However, age strongly affects clinical outcome in low-risk groups of both ferritin and NLR groups; hence, it should be considered as an early predictive factor of COVID-19 disease progression.

Attenuating the Effects of Novel COVID-19 (SARS-CoV-2) Infection-Induced Cytokine Storm and the Implications

The COVID-19 pandemic constitutes an arduous global health challenge, and the increasing number of fatalities calls for the speedy pursuit of a remedy. This review emphasizes the changing aspects of the COVID-19 disease, featuring the cytokine storm's pathological processes. Furthermore, we briefly reviewed potential therapeutic agents that may modulate and alleviate cytokine storms. The literature exploration was made using PubMed, Embase, MEDLINE, Google scholar, and China National Knowledge Infrastructure databases to retrieve the most recent literature on the etiology, diagnostic markers, and the possible prophylactic and therapeutic options for the management of cytokine storm in patients hospitalized with COVID-19 disease. The causative agent, severe acute respiratory coronavirus-2 (SARS-CoV-2), continually threatens the efficiency of the immune system of the infected individuals. As the first responder, the innate immune system provides primary protection against COVID-19, affecting the disease's progression, clinical outcome, and prognosis. Evidence suggests that the fatalities associated with COVID-19 are primarily due to hyper-inflammation and an aberrant immune function. Accordingly, the magnitude of the release of pro-inflammatory cytokines such as interleukin (IL)-1, (IL-6), and tumor necrosis alpha (TNF-α) significantly differentiate between mild and severe cases of COVID-19. The early prediction of a cytokine storm is made possible by several serum chemistry and hematological markers. The prompt use of these markers for diagnosis and the aggressive prevention and management of a cytokine release syndrome is critical in determining the level of morbidity and fatality associated with COVID-19. The prophylaxis and the rapid treatment of cytokine storm by clinicians will significantly enhance the fight against the dreaded COVID-19 disease.

Immunotherapy for COVID-19: Evolving treatment of viral infection and associated adverse immunological reactions

This review on COVID-19 immunotherapy enables a comparative analysis of the short-list of currently approved major vaccines. These include the Pfizer and Moderna first mRNA vaccines under FDA purview and the Oxford/AstraZeneca simian adenovirus-vectored vaccine (under UK-MHPRA guidance), all produced in record time, being safe and effective. The Pfizer and Moderna double dose vaccines have the clear edge in treatment efficacy, being in the 90% range compared to AstraZeneca in the average 70%. However, the AZ double dose vaccine has significant advantages with respect to lower cost and stability in storage. We enumerate several potential advances in the technology of the manufacturers: (1) combination vaccines such as testing AstraZeneca's product with a component of the Russian's Sputnik V to achieve durable immunity; (2) the potential for single dose vaccines coming on-line, and with Johnson & Johnson/Janssen; and (3) the need for refined thermotolerant formulations obviating the need for cold storage. As an adjunct to vaccinotherapy, affinity adsorption column technology is another facet recruited in the processing of corona convalescent plasma/cryosupernatant to concentrate neutralizing antibodies against the virus. Clinical trials, to date, of infected patients have been indeterminate as to whether plasmapheresis-based products are effective or not. This is due to the failure to standardize the composition of the plasma derived component, ambiguous clinical indications for use in human subjects, and inconsistent timing of administration in the course of the infection. Known T-cell lymphopenia, which is attendant to progressive viral infection and immune driven inflammation, may be a quantitative surrogate biological marker as to when to start treatment. This is not only for initiating plasmapheresis-based therapeutics but also the judicious selection of ancillary pharmaceuticals, ie. monoclonal antibodies, recombinant proteins and anti-viral drugs.

Comprehensive transcriptomic analysis of COVID-19 blood, lung, and airway

SARS-CoV2 is a previously uncharacterized coronavirus and causative agent of the COVID-19 pandemic. The host response to SARS-CoV2 has not yet been fully delineated, hampering a precise approach to therapy. To address this, we carried out a comprehensive analysis of gene expression data from the blood, lung, and airway of COVID-19 patients. Our results indicate that COVID-19 pathogenesis is driven by populations of myeloid-lineage cells with highly inflammatory but distinct transcriptional signatures in each compartment. The relative absence of cytotoxic cells in the lung suggests a model in which delayed clearance of the virus may permit exaggerated myeloid cell activation that contributes to disease pathogenesis by the production of inflammatory mediators. The gene expression profiles also identify potential therapeutic targets that could be modified with available drugs. The data suggest that transcriptomic profiling can provide an understanding of the pathogenesis of COVID-19 in individual patients.

Dipeptidylpeptidase-4 levels and DPP4 gene polymorphisms in patients with COVID-19. Association with disease and with severity

Background

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes de COVID-19 disease use as a principal receptor the angiotensin-converting enzyme-2 (ACE2). It has been suggested that dipeptidyl peptidase-4 (DPP4) can be another possible receptor for this virus. The present study aimed to establish if the DPP4 levels and DPP4 polymorphisms are associated with COVID-19 disease and its severity.

Methods

The study included 107 COVID-19 patients and 263 matched-healthy controls. Fifty patients required invasive mechanical ventilation. The DPP4 was quantified in serum using the Bioplex system. Based on the previous results and the functional prediction analysis, we select for the study 5 DPP4 polymorphisms (rs12617336, rs12617656, rs1558957, rs3788979, and rs17574) and these were determined using the 5´exonuclease TaqMan assays.

Results

Low levels of DPP4 were observed in COVID-19 patients (46.5 [33.1–57.7] ng/mL) when compared to healthy controls (125.3 [100.3–157.3] ng/mL) (P < 0.0001). Also, patients that required mechanical ventilation showed lower DPP4 levels (42.8 [29.8–56.9] ng/mL) than those that did not need this procedure (49.2 [39.9–65.6] ng/mL) (P = 0.012). DPP4 levels correlated negatively with age, fibrinogen, and platelet levels, and positively with albumin, alanine aminotransferase, and percentage of neutrophils. The DPP4 rs3788979 polymorphism was associated with a high risk of COVID-19 disease and, the TT genotype carriers had the lowest DPP4 levels.

Conclusions

In summary, in the present study, an association of low levels of DPP4 with COVID-19 disease and severity was found. The association of the DPP4 rs3788979 polymorphism with COVID-19 is also reported.

Immunological Characteristics in Type 2 Diabetes Mellitus Among COVID-19 Patients

Clinical Trial Registration

www.ClinicalTrials.gov, identifier: NCT04365634.

Context

Diabetes mellitus was associated with increased severity and mortality of disease in COVID-19 pneumonia. So far the effect of type 2 diabetes (T2DM) or hyperglycemia on the immune system among COVID-19 disease has remained unclear.

Objective

We aim to explore the clinical and immunological features of type 2 diabetes mellitus (T2DM) among COVID-19 patients.

Design and Methods

In this retrospective study, the clinical and immunological characteristics of 306 hospitalized confirmed COVID-19 patients (including 129 diabetic and 177 non-diabetic patients) were analyzed. The serum concentrations of laboratory parameters including cytokines and numbers of immune cells were measured and compared between diabetic and non-diabetic groups.

Results

Compared with non-diabetic group, diabetic cases more frequently had lymphopenia and hyperglycemia, with higher levels of urea nitrogen, myoglobin, D-dimer and ferritin. Diabetic cases indicated the obviously elevated mortality and the higher levels of cytokines IL-2R, IL-6, IL-8, IL-10, and TNF-α, as well as the distinctly reduced Th1/Th2 cytokines ratios compared with non-diabetic cases. The longitudinal assays showed that compared to that at week 1, the levels of IL-6 and IL-8 were significantly elevated at week 2 after admission in non-survivors of diabetic cases, whereas there were greatly reductions from week 1 to week 2 in survivors of diabetic cases. Compared with survival diabetic patients, non-survival diabetic cases displayed distinct higher serum concentrations of IL-2R, IL-6, IL-8, IL-10, TNF-α, and lower Th1/Th2 cytokines ratios at week 2. Samples from a subset of participants were evaluated by flow cytometry for the immune cells. The counts of peripheral total T lymphocytes, CD4+ T cells, CD8+ T cells and NK cells were markedly lower in diabetic cases than in non-diabetic cases. The non-survivors showed the markedly declined counts of CD8+ T cells and NK cells than survivors.

Conclusion

The elevated cytokines, imbalance of Th1/Th2 cytokines ratios and reduced of peripheral numbers of CD8+ T cells and NK cells might contribute to the pathogenic mechanisms of high mortality of COVID-19 patients with T2DM.

Age cohorts stratified according to age-distributions of COVID-19 morbidity statistics identify uniquely age-dependent CD3+CD8+ T-cell lymphocytopenia in COVID-19 patients without comorbidities on admission

If age boundaries are arbitrarily or roughly defined, age-related analyses can result in questionable findings. Here, we aimed to delineate the uniquely age-dependent immune features of coronavirus disease 2019 (COVID-19) in a retrospective study of 447 patients, stratified according to age distributions of COVID-19 morbidity statistics into well-defined age-cohorts (2–25y, 26–38y, 39–57y, 58–68y, and 69–79y). Age-dependent susceptibilities and severities of the disease were observed in COVID-19 patients. A comparison of the lymphocyte counts among the five age-groups indicated that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection led to age-dependent lymphopenia. Among the lymphocyte subsets, the CD8⁺ T cell count alone was significantly and age-dependently decreased (520, 385, 320, 172, and 139 n/μl in the five age-groups, respectively). In contrast, the CD4⁺ T cell, B cell, and natural killer cell counts did not differ among age-cohorts. Age and CD8⁺ T cell counts (r=‒0.435, p<0.0001) were negatively correlated in COVID-19 patients. Moreover, SARS-CoV-2 infection age-dependently increased the plasma C-reactive protein concentrations (2.0, 5.0, 9.0, 11.6, and 36.1 mg/L in the five age-groups, respectively). These findings can be used to elucidate the role of CD8⁺ T cells in age-related pathogenesis and to help develop therapeutic strategies for COVID-19.

Sex-based differences in severity and mortality in COVID-19

The current coronavirus disease (COVID‐19) pandemic caused by novel severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) has a male bias in severity and mortality. This is consistent with previous coronavirus pandemics such as SARS‐CoV and MERS‐CoV, and viral infections in general. Here, we discuss the sex‐disaggregated epidemiological data for COVID‐19 and highlight underlying differences that may explain the sexual dimorphism to help inform risk stratification strategies and therapeutic options.

Impact of SARS-CoV-2 on the clinical outcomes and placental pathology of pregnant women and their infants: A systematic review

Pregnant women are susceptible to viral infections due to physiological changes such as cell-mediated immunity. No severe adverse pregnancy or neonatal outcomes have been consistently reported in 2019 novel coronavirus disease (COVID-19) positive pregnancy cases. There are controversies around the role of COVID-19 in pregnancy. A systematic review was conducted to examine clinical maternal and neonatal clinical outcomes. Studies were included if they reported SARS-CoV-2 infection among pregnant women and/or COVID-19 positive neonates as validated by positive antibody testing or viral testing using polymerase chain reaction. Case series, case reports, case-control studies, and comparative studies were included. Eight hundred and thirty-seven records were identified, resulting in 525 records for level I screening. Forty-one were included after full-text review. Results suggest elevated rates of intensive care unit (ICU) admission, gestational diabetes, preeclampsia, C-sections, pre-term birth, and C-reactive protein (CRP) in comparison to pregnant women without SARS-CoV-2. Careful monitoring of pregnancies with SARS-CoV-2 is recommended.

Lymphocyte subsets early predict mortality in a large series of hospitalized COVID-19 patients in Spain

The role of lymphocytes and their main subsets as prognostic factors of death in SARS-CoV-2-infected patients remains unclear, with no information obtained from patients outside China. We aimed to assess whether measuring lymphocyte subpopulations added clinical value to the total lymphocyte counting regarding mortality when they were simultaneously tested at hospital admission. Peripheral blood was analysed in 701 polymerase chain reaction (PCR)-confirmed consecutive patients by lysed-no washed flow cytometry. Demographic and clinical features were registered in electronic medical records. Statistical analysis was performed after a 3-month follow-up. The 112 patients who died were older and had significantly higher frequencies of known co-morbidities than survivor COVID-19 patients. A significant reduction in total lymphocytes, CD3+ , CD4+ , CD8+ and CD19+ counts and CD3+ percentage was found in the group of deceased patients (P < 0·001), while the percentage of CD56+ /CD16+ natural killer (NK) cells was significantly higher (P < 0·001). Multivariate logistic regression analysis showed a significantly increased risk of in-hospital death associated to age [odds ratio (OR) = 2·36, 95% confidence interval (CI) = 1·9-3·0 P < 0·001]; CD4+  T counts ≤ 500 cells/μl, (OR = 2·79, 95% CI = 1·1-6·7, P = 0·021); CD8+  T counts ≤ 100 cells/μl, (OR = 1·98, 95% CI = 1·2-3·3) P = 0·009) and CD56+ /CD16+ NK ≥ 30%, (OR = 1·97, 95% CI = 1·1-3·1, P = 0·002) at admission, independent of total lymphocyte numbers and co-morbidities, with area under the curve 0·85 (95% CI = 0·81-0·88). Reduced counts of CD4+ and CD8+ T cells with proportional expansion of NK lymphocytes at admission were prognostic factors of death in this Spanish series. In COVID-19 patients with normal levels of lymphocytes or mild lymphopenia, imbalanced lymphocyte subpopulations were early markers of in-hospital mortality.

SARS-CoV-2: phylogenetic origins, pathogenesis, modes of transmission, and the potential role of nanotechnology

The COVID-19 pandemic has elicited a rapid response from the scientific community with significant advances in understanding the causative pathogen (SARS-CoV-2). Mechanisms of viral transmission and pathogenesis, as well as structural and genomic details, have been reported, which are essential in guiding containment, treatment, and vaccine development efforts. Here, we present a concise review of the recent research in these domains and an exhaustive analysis of the genomic origins of SARS-CoV-2. Particular emphasis has been placed on the pathology and disease progression of COVID-19 as documented by recent clinical studies, in addition to the characteristic immune responses involved therein. Furthermore, we explore the potential of nanomaterials and nanotechnology to develop diagnostic tools, drug delivery systems, and personal protective equipment design within the ongoing pandemic context. We present this as a ready resource for researchers to gain succinct, up-to-date insights on SARS-CoV-2.

The Impact of SARS-CoV-2 on the Human Immune System and Microbiome

A recent outbreak of coronavirus disease 2019 (COVID-19) caused by the single-stranded enveloped RNA virus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has developed into a global pandemic, after it was first reported in Wuhan in December 2019. SARS-CoV-2 is an emerging virus, and little is known about the basic characteristics of this pathogen, the underlying mechanism of infection, and the potential treatments. The immune system has been known to be actively involved in viral infections. To facilitate the development of COVID-19 treatments, the understanding of immune regulation by this viral infection is urgently needed. This review describes the mechanisms of immune system involvement in viral infections and provides an overview of the dysregulation of immune responses in COVID-19 patients in recent studies. Furthermore, we emphasize the role of gut microbiota in regulating immunity and summarized the impact of SARS-CoV-2 infection on the composition of the microbiome. Overall, this review provides insights for understanding and developing preventive and therapeutic strategies by regulating the immune system and microbiota.

Hematological Findings in COVID-19 and Insights to Stem Cell Therapy: From Bench to Practice

Context: As the COVID-19 was spreading to all countries, its manifestations were identifying gradually, which were related to several organs. Evidence Acquisition: COVID-19 is associated with distinct hematological changes, increased serum inflammatory markers, and coagulopathy. Most of these changes are related to the patients’ prognosis and mortality, particularly in those with severe disease. Results: Firstly, we discussed the associations between COVID-19 clinical features and complications, and secondly, its hematological findings and coagulopathy are investigated. Conclusions: Such associations not only may shed light on our prognostic view of patients with COVID-19 but also will entail significant therapeutic implications. One of its key implications is to utilize the mesenchymal stem cells (MSCs) to treat patients with COVID-19. Herein, this kind of novel therapy will be discussed, as well.

Hematological Abnormalities in COVID-19: A Narrative Review

COVID-19 is caused by SARS-CoV-2. Although pulmonary manifestations have been identified as the major symptoms, several hematological abnormalities have also been identified. This review summarizes the reported hematological abnormalities (changes in platelet, white blood cell, and hemoglobin, and coagulation/fibrinolytic alterations), explores their patho-mechanisms, and discusses its management. Common hematological abnormalities in COVID-19 are lymphopenia, thrombocytopenia, and elevated D-dimer levels. These alterations are significantly more common/prominent in patients with severe COVID-19 disease, and thus may serve as a possible biomarker for those needing hospitalization and intensive care unit care. Close attention needs to be paid to coagulation abnormalities, and steps should be taken to prevent these occurring or to mitigate their harmful effects. The effect of COVID-19 in patients with hematological abnormalities and recognized hematological drug toxicities of therapies for COVID-19 are also outlined.

Influence of age and gender on the epidemic of COVID-19 : Evidence from 177 countries and territories-an exploratory, ecological study

BACKGROUND

The pandemic of coronavirus disease 2019 (COVID-19) is spreading worldwide with an uncertain ultimate impact on every aspect of human society. Recognizing the groups with higher susceptibility and fatality are in urgent need.

METHODS

We retrieved the total number of confirmed incident and death cases of COVID-19 in 177 countries/territories from the Center for Systems Science and Engineering (CSSE) at Johns Hopkins University (JHU). Data of age and gender composition were collected from the United Nations Department of Economic and Social Affairs. Spearman's correlation analysis was used to explore the association between the composition of age and gender and the incidence rate (IRC), case fatality rate (CFRC), and mortality rate of COVID-19 (MRC). Multiple comparisons were adjusted by the Bonferroni method, and the threshold p-value was set as p < 0.01. Software SPSS 23.0, ArcGIS 10.6, and GraphPad Prism 8.0 were used to generate our results.

RESULTS

Median age was positively correlated to IRC, CFRC and MRC (r_s = 0.60; r_s = 0.27; r_s = 0.61, p < 0.0001 for all). The age-dependent correlation between people over 65 years of age with IRC was higher in females, while the correlation between age distribution and CFRC as well as MRC was higher in males (p < 0.0001 for all). Besides, we found the age-gender-dependent differences were correlated to IRC in places with high income and associated with CFRC in non-high income countries/territories.

CONCLUSION

The correlation between the composition of age and gender and the epidemic characteristics of COVID-19 confirmed previous points that females are more susceptible to COVID-19. The results remind us that more attention should be paid to male patients, particularly those over 65 years old for enhanced clinical management.

R, Putty K, Dholaniya PS, Puli RK, Pakalapati S, S. S, K. S, Doodipala MR, Upadhyay AA, Bosinger SE, Amara RR, Kondapi AK. Clinical and whole genome characterization of SARS-CoV-2 in India

We report clinical profile of hundred and nine patients with SARS CoV-2 infection, and whole genome sequences (WGS) of seven virus isolates from the first reported cases in India, with various international travel histories. Comorbidities such as diabetes, hypertension, and cardiovascular disease were frequently associated with severity of the disease. WBC and neutrophil counts showed an increase, while lymphocyte counts decreased in patients with severe infection suggesting a possible neutrophil mediated organ damage, while immune activity may be diminished with decrease in lymphocytes leading to disease severity. Increase in SGOT, SGPT and blood urea suggests the functional deficiencies of liver, heart, and kidney in patients who succumbed to the disease when compared to the group of recovered patients. The WGS analysis showed that these isolates were classified into two clades: I/A3i, and A2a (four according to GISAID: O, L, GR, and GH). Further, WGS phylogeny and travel history together indicate possible transmission from Middle East and Europe. Three S protein variants: Wuhan reference, D614G, and Y28H were identified predicted to possess different binding affinities to host ACE2.

MuLBSTA score is a useful tool for predicting COVID-19 disease behavior

BACKGROUND

The prediction of COVID-19 disease behavior in the early phase of infection is challenging but urgently needed. MuLBSTA score is a scoring system that predicts the mortality of viral pneumonia induced by a variety of viruses, including coronavirus, but the scoring system has not been verified in novel coronavirus pneumonia. The aim of this study was to validate this scoring system for estimating the risk of disease worsening in patients with COVID-19.

METHODS

This study included the patients who were treated between April 1 st and March 13 th , 2020. The patients were classified into mild, moderate, and severe groups according to the extent of respiratory failure. MuLBSTA score was applied to estimate the risk of disease worsening in each severity group and we validated the utility of the scoring system.

RESULTS

A total of 72 patients were analyzed. Among the 46 patients with mild disease, 17 showed disease progression to moderate or severe disease after admission. The model showed a sensitivity of 100% and a specificity of only 34.5% with a cut-off value of 5 points. Among the 55 patients with mild or moderate disease, 6 deteriorated to severe disease, and the model showed a sensitivity of 83.3% and a specificity of 71.4% with a cut-off value of 11 points.

CONCLUSIONS

This study showed that MuLBSTA score is a potentially useful tool for predicting COVID-19 disease behavior. This scoring system may be used as one of the criteria to identify high-risk patients worsening to life-threatening status.

Case Report: B Lymphocyte Disorders Under COVID-19 Inflammatory Pressure

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infects humans through the angiotensin converting enzyme-2 (ACE-2) receptor expressed on many cells, including lymphocytes. In Covid-19 patients IL-6 is overexpressed, and hyperactivated plasmacytoid lymphocytes are detected in peripheral blood film. We hypothesize that, due to the unpredictable interaction between the new virus and the B cell lineage of infected patients, a cascade of out of control events can ensue, capable of determining unexpected pathologic disorders involving such lineage. Here we report two cases of autoimmune hemolytic anemia (AIHA) and two cases of B-cell hematological malignancies developed or reactivated during acute SARS-CoV-2 infection. The temporal relationship of the events may suggest a potential causal relationship between SARS-CoV-2 infection and the hematopoietic disorders. We suggest that special attention should be paid to COVID-19 patients with underlining B cell lineage disorders.

IMPACT-Scot 2 report on COVID-19 in hip fracture patients

AIMS

The primary aim was to determine the influence of COVID-19 on 30-day mortality following hip fracture. Secondary aims were to determine predictors of COVID-19 status on presentation and later in the admission; the rate of hospital acquired COVID-19; and the predictive value of negative swabs on admission.

METHODS

A nationwide multicentre retrospective cohort study was conducted of all patients presenting with a hip fracture to 17 Scottish centres in March and April 2020. Demographics, presentation blood tests, COVID-19 status, Nottingham Hip Fracture Score, management, length of stay, and 30-day mortality were recorded.

RESULTS

In all, 78/833 (9.4%) patients were diagnosed with COVID-19. The 30-day survival of patients with COVID-19 was significantly lower than for those without (65.4% vs 91%; p < 0.001). Diagnosis of COVID-19 within seven days of admission (likely community acquired) was independently associated with male sex (odds ratio (OR) 2.34, p = 0.040, confidence interval (CI) 1.04 to 5.25) and symptoms of COVID-19 (OR 15.56, CI 6.61 to 36.60, p < 0.001). Diagnosis of COVID-19 made between seven and 30 days of admission to hospital (likely hospital acquired) was independently associated with male sex (OR 1.73, CI 1.05 to 2.87, p = 0.032), Nottingham Hip Fracture Score ≥ 7 (OR 1.91, CI 1.09 to 3.34, p = 0.024), pulmonary disease (OR 1.68, CI 1.00 to 2.81, p = 0.049), American Society of Anesthesiologists (ASA) grade ≥ 3 (OR 2.37, CI 1.13 to 4.97, p = 0.022), and length of stay ≥ nine days (OR 1.98, CI 1.18 to 3.31, p = 0.009). A total of 38 (58.5%) COVID-19 cases were probably hospital acquired infections. The false-negative rate of a negative swab on admission was 0% in asymptomatic patients and 2.9% in symptomatic patients.

CONCLUSION

COVID-19 was independently associated with a three times increased 30-day mortality rate. Nosocomial transmission may have accounted for approximately half of all cases during the first wave of the pandemic. Identification of risk factors for having COVID-19 on admission or acquiring COVID-19 in hospital may guide pathways for isolating or shielding patients respectively. Length of stay was the only modifiable risk factor, which emphasizes the importance of high-quality and timely care in this patient group. Cite this article: Bone Joint J 2021;103-B(5):888-897.

Diagnosing Coronavirus Disease 2019 (COVID-19): Efficient Harris Hawks-Inspired Fuzzy K-Nearest Neighbor Prediction Methods

This study is devoted to proposing a useful intelligent prediction model to distinguish the severity of COVID-19, to provide a more fair and reasonable reference for assisting clinical diagnostic decision-making. Based on patients' necessary information, pre-existing diseases, symptoms, immune indexes, and complications, this article proposes a prediction model using the Harris hawks optimization (HHO) to optimize the Fuzzy K-nearest neighbor (FKNN), which is called HHO-FKNN. This model is utilized to distinguish the severity of COVID-19. In HHO-FKNN, the purpose of introducing HHO is to optimize the FKNN's optimal parameters and feature subsets simultaneously. Also, based on actual COVID-19 data, we conducted a comparative experiment between HHO-FKNN and several well-known machine learning algorithms, which result shows that not only the proposed HHO-FKNN can obtain better classification performance and higher stability on the four indexes but also screen out the key features that distinguish severe COVID-19 from mild COVID-19. Therefore, we can conclude that the proposed HHO-FKNN model is expected to become a useful tool for COVID-19 prediction.

Elevated plasma IL-6 and CRP levels are associated with adverse clinical outcomes and death in critically ill SARS-CoV-2 patients: inflammatory response of SARS-CoV-2 patients

Background

SARS coronavirus 2 (SARS-CoV-2) is responsible for high morbidity and mortality worldwide, mostly due to the exacerbated inflammatory response observed in critically ill patients. However, little is known about the kinetics of the systemic immune response and its association with survival in SARS-CoV-2+ patients admitted in ICU. We aimed to compare the immuno-inflammatory features according to organ failure severity and in-ICU mortality.

Methods

Six-week multicentre study (N = 3) including SARS-CoV-2+ patients admitted in ICU. Analysis of plasma biomarkers at days 0 and 3–4 according to organ failure worsening (increase in SOFA score) and 60-day mortality.

Results

101 patients were included. Patients had severe respiratory diseases with PaO2/FiO2 of 155 [111–251] mmHg), SAPS II of 37 [31–45] and SOFA score of 4 [3–7]. Eighty-three patients (83%) required endotracheal intubation/mechanical ventilation and among them, 64% were treated with prone position. IL-1β was barely detectable. Baseline IL-6 levels positively correlated with organ failure severity. Baseline IL-6 and CRP levels were significantly higher in patients in the worsening group than in the non-worsening group (278 [70–622] vs. 71 [29–153] pg/mL, P < 0.01; and 178 [100–295] vs. 100 [37–213] mg/L, P < 0.05, respectively). Baseline IL-6 and CRP levels were significantly higher in non-survivors compared to survivors but fibrinogen levels and lymphocyte counts were not different between groups. After adjustment on SOFA score and time from symptom onset to first dosage, IL-6 and CRP remained significantly associated with mortality. IL-6 changes between Day 0 and Day 3–4 were not different according to the outcome. A contrario, kinetics of CRP and lymphocyte count were different between survivors and non-survivors.

Conclusions

In SARS-CoV-2+ patients admitted in ICU, a systemic pro-inflammatory signature was associated with clinical worsening and 60-day mortality.

Prediction of adverse clinical outcomes in patients with coronavirus disease 2019

OBJECTIVE

This study aims to investigate blood and biochemical laboratory findings in patients with coronavirus disease (COVID-19) and analyze the potential predictors of poor outcome in patients with COVID-19.

METHODS

The clinical, laboratory, and outcome data of 87 patients with COVID-19 were collected and retrospectively analyzed. Only data collected at the time of admission were used in the analysis for predictors of poor outcome. These patients were divided into two groups: the adverse prognosis group (36 patients) and the non-adverse prognosis group (51 patients). The adverse prognosis of COVID-19 patients was defined as admission to the intensive care unit or death.

RESULTS

On the univariate analysis, age, white blood cell (WBC) count, neutrophil counts, lymphocytes count, neutrophils-to-lymphocytes ratio (NLR), interleukin-6, albumin-to-globulin ratio (AGR), albumin, lactate dehydrogenase, glutamyl transpeptidase, and blood glucose were found to be the significant predictors. On the multivariate analysis, the predictors of poor outcome of patients with COVID-19 were NLR (OR = 2.741, [95% CI = 1.02 ~ 7.35], P = .045) and IL-6 (OR = 1.405, [95% CI = 1.04 ~ 1.89, P = .025]). The receiver operating characteristic (ROC) curve revealed that the AUC of NLR, interleukin-6, pneumonia severity index (PSI) score, and Confusion-Urea-Respiratory Rate-Blood pressure-65 (CURB-65) score were 0.883, 0.852, 0.824, and 0.782, respectively.

CONCLUSION

High interleukin-6 (6 pg/mL, cuff value) and NLR (4.48, cuff value) can be used to predict poor outcomes in patients with COVID-19 on admission, thus can serve as a beneficial tool for timely identifying COVID-19 patients prone to poor outcome and reduce patient mortality through early intervention.

T Cells: Warriors of SARS-CoV-2 Infection

Severe infection with severe acute respiratory syndrome coronavirus (SARS-CoV)-2 is characterized by massive cytokine release and T cell loss. The exaggerated host immune response, incapable of viral clearance, instead aggravates respiratory distress, as well as cardiac, and/or damage to other organs. The mortality pattern of SARS-CoV-2 infection, higher in older versus younger adults and almost absent in children, is possibly caused by the effects of age and pre-existing comorbidities on innate and adaptive immunity. Here, we speculate that the abnormal and excessive immune response to SARS-CoV-2 infection partly depends on T cell immunological memory, which is more pronounced in adults compared with children, and may significantly contribute to immunopathology and massive collateral damage in coronavirus disease 2019 (COVID-19) patients.

Road Map to Understanding SARS-CoV-2 Clinico-Immunopathology and COVID-19 Disease Severity

SARS-CoV-2, a novel coronavirus, was first identified in Wuhan, China in December 2019. The rapid spread of the virus worldwide prompted the World Health Organization (WHO) to declare COVID-19 a pandemic in March 2020. COVID-19 discontinuing's a global health crisis. Approximately 80% of the patients infected with SARS-CoV-2 display undetectable to mild inflammation confined in the upper respiratory tract. In remaining patients, the disease turns into a severe form affecting almost all major organs predominantly due to an imbalance of innate and adaptive arms of host immunity. The purpose of the present review is to narrate the virus's invasion through the system and the host's reaction. A thorough discussion on disease severity is also presented regarding the behavior of the host's immune system, which gives rise to the cytokine storm particularly in elderly patients and those with comorbidities. A multifaceted yet concise description of molecular aspects of disease progression and its repercussion on biochemical and immunological features in infected patients is tabulated. The summary of pathological, clinical, immunological, and molecular accounts discussed in this review is of theranostic importance to clinicians for early diagnosis of COVID-19 and its management.

[Analysis of the correlation between lymphocyte subsets and severity of corona virus disease 19]

OBJECTIVE

To understand the differences in lymphocyte subsets in patients with different clinical classifications of corona virus disease 19 (COVID-19).

METHODS

Eighty-one patients with COVID-19 who were admitted to the isolation ward under the responsibility of three medical aid teams in the Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, from February 8, 2020 to March 28, 2020, were selected to collect clinical data. According to the relevant diagnostic criteria, the disease status of the patients was classified into moderate cases (n=35), severe cases (n=39) and critical cases (n=7) when lymphocyte subset testing was performed. Their blood routine tests, lymphocyte subsets and other indicators were tested to compare whether there were differences in each indicator between the patients of different clinical classification groups.

RESULTS

The differences in the absolute count of total lymphocytes, T-lymphocytes, CD4⁺T-lymphocytes, CD8⁺T-lymphocytes and natural killer (NK) cells among the three groups of patients were all statistically significant (P < 0.05), and the critical cases were significantly lower than the moderate and severe cases in the above indicators, and the indicators showed a decreasing trend with the severity of the disease. In 22 patients, the six indicators of the absolute count of T-lymphocytes, B-lymphocytes, CD4⁺T-lymphocytes, CD8⁺T-lymphocytes and NK cells, CD4⁺/CD8⁺ ratio were all within the normal reference range in the first test, and 59 patients had abnormalities of the above indicators, with the absolute count of NK cells and CD8⁺ T lymphocytes decreasing most frequently (61%, 56%). The patients with the absolute count of NK cells and CD8⁺ T lymphocytes below the normal reference range were one group, and the remaining abnormal patients were the other group. There were more critical cases in the former group (moderate : severe : critical cases were 4 : 8 : 7 vs. 19 : 21 : 0, respectively, P=0.001), and all the deaths were in this group (6 cases vs. 0 case, P=0.001). The absolute B lymphocyte count was below the normal reference range in 15 patients, and the remaining 64 cases were within the normal range. The ratio of moderate, severe and critical cases in the reduced group was 4 : 7 : 4, and the ratio of critical cases was more in normal group which was 30 : 31 : 3, and the difference between the two groups was statistically significant (P=0.043).

CONCLUSION

The more critical the clinical subtype of patients with COVID-19, the lower the absolute count of each subset of lymphocytes.

[Analysis of the correlation between lymphocyte subsets and severity of corona virus disease 19]

OBJECTIVE

To understand the differences in lymphocyte subsets in patients with different clinical classifications of corona virus disease 19 (COVID-19).

METHODS

Eighty-one patients with COVID-19 who were admitted to the isolation ward under the responsibility of three medical aid teams in the Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, from February 8, 2020 to March 28, 2020, were selected to collect clinical data. According to the relevant diagnostic criteria, the disease status of the patients was classified into moderate cases (n=35), severe cases (n=39) and critical cases (n=7) when lymphocyte subset testing was performed. Their blood routine tests, lymphocyte subsets and other indicators were tested to compare whether there were differences in each indicator between the patients of different clinical classification groups.

RESULTS

The differences in the absolute count of total lymphocytes, T-lymphocytes, CD4+T-lymphocytes, CD8+T-lymphocytes and natural killer (NK) cells among the three groups of patients were all statistically significant (P < 0.05), and the critical cases were significantly lower than the moderate and severe cases in the above indicators, and the indicators showed a decreasing trend with the severity of the disease. In 22 patients, the six indicators of the absolute count of T-lymphocytes, B-lymphocytes, CD4+T-lymphocytes, CD8+T-lymphocytes and NK cells, CD4+/CD8+ ratio were all within the normal reference range in the first test, and 59 patients had abnormalities of the above indicators, with the absolute count of NK cells and CD8+ T lymphocytes decreasing most frequently (61%, 56%). The patients with the absolute count of NK cells and CD8+ T lymphocytes below the normal reference range were one group, and the remaining abnormal patients were the other group. There were more critical cases in the former group (moderate : severe : critical cases were 4 : 8 : 7 vs. 19 : 21 : 0, respectively, P=0.001), and all the deaths were in this group (6 cases vs. 0 case, P=0.001). The absolute B lymphocyte count was below the normal reference range in 15 patients, and the remaining 64 cases were within the normal range. The ratio of moderate, severe and critical cases in the reduced group was 4 : 7 : 4, and the ratio of critical cases was more in normal group which was 30 : 31 : 3, and the difference between the two groups was statistically significant (P=0.043).

CONCLUSION

The more critical the clinical subtype of patients with COVID-19, the lower the absolute count of each subset of lymphocytes.

Clinical features and risk factors for severe inpatients with COVID-19: A retrospective study in China

Background

A worldwide outbreak of coronavirus disease (COVID-19), since 2019, has brought a disaster to people all over the world. Many researchers carried out clinical epidemiological studies on patients with COVID-19 previously, but risk factors for patients with different levels of severity are still unclear.

Methods

562 patients with laboratory-confirmed COVID-19 from 12 hospitals in China were included in this retrospective study. Related clinical information, therapies, and imaging data were extracted from electronic medical records and compared between patients with severe and non-severe status. We explored the risk factors associated with different severity of COVID-19 patients by logistic regression methods.

Results

Based on the guideline we cited, 509 patients were classified as non-severe and 53 were severe. The age range of whom was 5–87 years, with a median age of 47 (IQR 35.0–57.0). And the elderly patients (older than 60 years old) in non-severe group were more likely to suffer from fever and asthma, accompanied by higher level of D-dimer, red blood cell distribution width and low-density lipoprotein. Furthermore, we found that the liver and kidney function of male patients was worse than that of female patients in both severe and non-severe groups with different age levels, while the severe females had faster ESR and lower inflammatory markers. Of major laboratory markers in non-severe cases, baseline albumin and the lymphocyte percentage were higher, while the white blood cell and the neutrophil count were lower. In addition, severe patients were more likely to be accompanied by an increase in cystatin C, mean hemoglobin level and a decrease in oxygen saturation. Besides that, advanced age and indicators such as count of white blood cell, glucose were proved to be the most common risk factors preventing COVID-19 patients from aggravating.

Conclusion

The potential risk factors found in our study have shown great significance to prevent COVID-19 patients from aggravating and turning to critical cases during treatment. Meanwhile, focusing on gender and age factors in groups with different severity of COVID-19, and paying more attention to specific clinical symptoms and characteristics, could improve efficacy of personalized intervention to treat COVID-19 effectively.

Predicting Disease Severity and Outcome in COVID-19 Patients: A Review of Multiple Biomarkers

CONTEXT.—

An abundance of clinical reports focused on specific laboratory parameters have been reported on coronavirus disease 19 (COVID-19), but a systematic analysis synthesizing these findings has not been performed.

OBJECTIVE.—

To review and summarize the current available literature on the predictive role of various biomarkers in COVID-19 patients.

DATA SOURCES.—

A literature search was performed using databases including PubMed, medRxiv, and bioRxiv. A total of 72 papers were reviewed, including 54 peer-reviewed papers and 18 non-peer-reviewed preprints.

CONCLUSIONS.—

Although the markers are considered nonspecific, acute-phase reactants, including C-reactive protein (CRP), ferritin, serum amyloid A (SAA), and procalcitonin, were reported as sensitive markers of acute COVID-19 disease. Significantly elevated white blood cell count; marked lymphopenia; decreased CD3, CD4, or CD8 T-lymphocyte counts; high neutrophil count; thrombocytopenia; and markedly elevated inflammatory biomarkers were associated with severe disease and the risk of developing sepsis with rapid progression. Trends observed by serial laboratory measurements during hospitalization, including progressive decrease of lymphocyte count, thrombocytopenia, elevated CRP, procalcitonin, increased liver enzymes, decreased renal function, and coagulation derangements, were more common in critically ill patient groups and associated with a high incidence of clinical complications. Elevated interleukin 6 level and markedly increased SAA were most often reported in severely and critically ill patients. Indicators of systemic inflammation, such as neutrophil to lymphocyte ratio, systemic immune-inflammation index, or COVID-19 Severity Score, may be used to predict disease severity, outcome, and mortality. Interpretation of the data reported in the studies reviewed here is limited because of the study design (mostly retrospective), limited sample size, and a lack of defined clinical criteria.

Specific dynamic variations in the peripheral blood lymphocyte subsets in COVID-19 and severe influenza A patients: a retrospective observational study

Background

Both COVID-19 and influenza A contribute to increased mortality among the elderly and those with existing comorbidities. Changes in the underlying immune mechanisms determine patient prognosis. This study aimed to analyze the role of lymphocyte subsets in the immunopathogenesisof COVID-19 and severe influenza A, and examined the clinical significance of their alterations in the prognosis and recovery duration.

Methods

By retrospectively reviewing of patients in four groups (healthy controls, severe influenza A, non-severe COVID-19 and severe COVID-19) who were admitted to Ditan hospital between 2018 to 2020, we performed flow cytometric analysis and compared the absolute counts of leukocytes, lymphocytes, and lymphocyte subsets of the patients at different time points (weeks 1–4).

Results

We reviewed the patients’ data of 94 healthy blood donors, 80 Non-severe-COVID-19, 19 Severe-COVID-19 and 37 severe influenza A. We found total lymphocytes (0.81 × 10⁹/L vs 1.74 × 10⁹/L, P = 0.001; 0.87 × 10⁹/L vs 1.74 × 10⁹/L, P < 0.0001, respectively) and lymphocyte subsets (T cells, CD4⁺ and CD8⁺ T cell subsets) of severe COVID-19 and severe influenza A patients to be significantly lower than those of healthy donors at early infection stages. Further, significant dynamic variations were observed at different time points (weeks 1–4).

Conclusions

Our study suggests the plausible role of lymphocyte subsets in disease progression, which in turn affects prognosis and recovery duration in patients with severe COVID-19 and influenza A.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-020-05637-9.

T cell immunobiology and cytokine storm of COVID-19

2019 coronavirus disease (COVID-19) presents as a newly recognized pneumonia and could rapidly progress into acute respiratory distress syndrome which has brought about a global pandemic. Until now, no curative therapy has been strongly recommended for COVID-19 except for personalized supportive care. T cells and virus-specific T cells are essential to protect against virus infection, including COVID-19. Delayed immune reconstitution (IR) and cytokine storm (CS) remain serious obstacles for the cure of COVID-19. Most COVID-19 patients, especially among elderly patients, had marked lymphopenia and increased neutrophils, but T cell counts in severe COVID-19 patients surviving the disease gradually restored later. Elevated pro-inflammatory cytokines, particularly IL-6, IL-10, IL-2 and IL-17, and exhausted T cells are found in peripheral blood and the lungs. It suggests that Thymosin α1 and adoptive COVID-19-specific T cells could improve IR, while convalescent plasma, IL-6 blockade, mesenchymal stem cells and corticosteroids could suppress CS. More clinical studies in this field worldwide are urgently warranted to pave the way for therapy of COVID-19 in the future.