Complement C5a and Clinical Markers as Predictors of COVID-19 Disease Severity and Mortality in a Multi-Ethnic Population.

Coronavirus disease-2019 (COVID-19) was declared as a pandemic by WHO in March 2020. SARS-CoV-2 causes a wide range of illness from asymptomatic to life-threatening. There is an essential need to identify biomarkers to predict disease severity and mortality during the earlier stages of the disease, aiding treatment and allocation of resources to improve survival. The aim of this study was to identify at the time of SARS-COV-2 infection patients at high risk of developing severe disease associated with low survival using blood parameters, including inflammation and coagulation mediators, vital signs, and pre-existing comorbidities. This cohort included 89 multi-ethnic COVID-19 patients recruited between July 14th and October 20th 2020 in Doha, Qatar. According to clinical severity, patients were grouped into severe (n=33), mild (n=33) and asymptomatic (n=23). Common routine tests such as complete blood count (CBC), glucose, electrolytes, liver and kidney function parameters and markers of inflammation, thrombosis and endothelial dysfunction including complement component split product C5a, Interleukin-6, ferritin and C-reactive protein were measured at the time COVID-19 infection was confirmed. Correlation tests suggest that C5a is a predictive marker of disease severity and mortality, in addition to 40 biological and physiological parameters that were found statistically significant between survivors and non-survivors. Survival analysis showed that high C5a levels, hypoalbuminemia, lymphopenia, elevated procalcitonin, neutrophilic leukocytosis, acute anemia along with increased acute kidney and hepatocellular injury markers were associated with a higher risk of death in COVID-19 patients. Altogether, we created a prognostic classification model, the CAL model (C5a, Albumin, and Lymphocyte count) to predict severity with significant accuracy. Stratification of patients using the CAL model could help in the identification of patients likely to develop severe symptoms in advance so that treatments can be targeted accordingly.

Endothelial dysfunction contributes to severe COVID-19 in combination with dysregulated lymphocyte responses and cytokine networks.

The systemic processes involved in the manifestation of life-threatening COVID-19 and in disease recovery are still incompletely understood, despite investigations focusing on the dysregulation of immune responses after SARS-CoV-2 infection. To define hallmarks of severe COVID-19 in acute disease (n = 58) and in disease recovery in convalescent patients (n = 28) from Hannover Medical School, we used flow cytometry and proteomics data with unsupervised clustering analyses. In our observational study, we combined analyses of immune cells and cytokine/chemokine networks with endothelial activation and injury. ICU patients displayed an altered immune signature with prolonged lymphopenia but the expansion of granulocytes and plasmablasts along with activated and terminally differentiated T and NK cells and high levels of SARS-CoV-2-specific antibodies. The core signature of seven plasma proteins revealed a highly inflammatory microenvironment in addition to endothelial injury in severe COVID-19. Changes within this signature were associated with either disease progression or recovery. In summary, our data suggest that besides a strong inflammatory response, severe COVID-19 is driven by endothelial activation and barrier disruption, whereby recovery depends on the regeneration of the endothelial integrity.

Lymphopenia and lung complications in patients with coronavirus disease-2019 (COVID-19): A retrospective study based on clinical data.

A rapid outbreak of novel coronavirus, coronavirus disease-2019 (COVID-19), has made it a global pandemic. This study focused on the possible association between lymphopenia and computed tomography (CT) scan features and COVID-19 patient mortality. The clinical data of 596 COVID-19 patients were collected from February 2020 to September 2020. The patients' serological survey and CT scan features were retrospectively explored. The median age of the patients was 56.7 ± 16.4 years old. Lung involvement was more than 50% in 214 COVID-19 patients (35.9%). The average blood lymphocyte percentage was 20.35 ± 10.16 (normal range, 20%-50%). Although the levels of C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) were high in more than 80% of COVID-19 patients; CRP, ESR, and platelet-to-lymphocyte ratio (PLR) may not indicate the in-hospital mortality of COVID-19. Patients with severe lung involvement and lymphopenia were found to be significantly associated with increased odds of death (odds ratio, 9.24; 95% confidence interval, 4.32-19.78). These results indicated that lymphopenia < 20% along with pulmonary involvement >50% impose a multiplicative effect on the risk of mortality. The in-hospital mortality rate of this group was significantly higher than other COVID-19 hospitalized cases. Furthermore, they meaningfully experienced a prolonged stay in the hospital (p = .00). Lymphocyte count less than 20% and chest CT scan findings with more than 50% involvement might be related to the patient's mortality. These could act as laboratory and clinical indicators of disease severity, mortality, and outcome.

Immunological Biomarkers of Fatal COVID-19: A Study of 868 Patients.

Information on the immunopathobiology of coronavirus disease 2019 (COVID-19) is rapidly increasing; however, there remains a need to identify immune features predictive of fatal outcome. This large-scale study characterized immune responses to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection using multidimensional flow cytometry, with the aim of identifying high-risk immune biomarkers. Holistic and unbiased analyses of 17 immune cell-types were conducted on 1,075 peripheral blood samples obtained from 868 COVID-19 patients and on samples from 24 patients presenting with non-SARS-CoV-2 infections and 36 healthy donors. Immune profiles of COVID-19 patients were significantly different from those of age-matched healthy donors but generally similar to those of patients with non-SARS-CoV-2 infections. Unsupervised clustering analysis revealed three immunotypes during SARS-CoV-2 infection; immunotype 1 (14% of patients) was characterized by significantly lower percentages of all immune cell-types except neutrophils and circulating plasma cells, and was significantly associated with severe disease. Reduced B-cell percentage was most strongly associated with risk of death. On multivariate analysis incorporating age and comorbidities, B-cell and non-classical monocyte percentages were independent prognostic factors for survival in training (n=513) and validation (n=355) cohorts. Therefore, reduced percentages of B-cells and non-classical monocytes are high-risk immune biomarkers for risk-stratification of COVID-19 patients.

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.

Clinical Features and Outcomes of 105 Hospitalized Patients With COVID-19 in Seattle, Washington.

BACKGROUND: Washington State served as the initial epicenter of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic in the United States. An understanding of the risk factors and clinical outcomes of hospitalized patients with coronavirus disease 2019 (COVID-19) may provide guidance for management. METHODS: All laboratory-confirmed COVID-19 cases in adults admitted to an academic medical center in Seattle, Washington, between 2 March and 26 March 2020 were included. We evaluated individuals with and without severe disease, defined as admission to the intensive care unit or death. RESULTS: One hundred five COVID-19 patients were hospitalized. Thirty-five percent were admitted from a senior home or skilled nursing facility. The median age was 69 years, and half were women. Three or more comorbidities were present in 55% of patients, with hypertension (59%), obesity (47%), cardiovascular disease (38%), and diabetes (33%) being the most prevalent. Most (63%) had symptoms for ≥5 days prior to admission. Only 39% had fever in the first 24 hours, whereas 41% had hypoxia at admission. Seventy-three percent of patients had lymphopenia. Of 50 samples available for additional testing, no viral coinfections were identified. Severe disease occurred in 49%. Eighteen percent of patients were placed on mechanical ventilation, and the overall mortality rate was 33%. CONCLUSIONS: During the early days of the COVID-19 epidemic in Washington State, the disease had its greatest impact on elderly patients with medical comorbidities. We observed high rates of severe disease and mortality in our hospitalized patients.

Hyperglycemia associated with lymphopenia and disease severity of COVID-19 in type 2 diabetes mellitus.

BACKGROUND: Coronavirus disease 2019 (COVID-19) has been declared a global pandemic. COVID-19 is more severe in people with diabetes. The identification of risk factors for predicting disease severity in COVID-19 patients with type 2 diabetes mellitus (T2DM) is urgently needed. METHODS: Two hundred and thirty-six patients with COVID-19 were enrolled in our study. The patients were divided into 2 groups: COVID-19 patients with or without T2DM. The patients were further divided into four subgroups according to the severity of COVID-19 as follows: Subgroup A included moderate COVID-19 patients without diabetes, subgroup B included severe COVID-19 patients without diabetes, subgroup C included moderate COVID-19 patients with diabetes, and subgroup D included severe COVID-19 patients with diabetes. The clinical features and radiological assessments were collected and analyzed. We tracked the dynamic changes in laboratory parameters and clinical outcomes during the hospitalization period. Multivariate analysis was performed using logistic regression to analyze the risk factors that predict the severity of COVID-19 with T2DM. RESULTS: Firstly, compared with the nondiabetic group, the COVID-19 with T2DM group had a higher erythrocyte sedimentation rate (ESR) and levels of C-reactive protein (CRP), interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α), and procalcitonin (PCT) but lower lymphocyte counts and T lymphocyte subsets, including CD3+ T cells, CD8+ T cells, CD4+ T cells, CD16 + CD56 cells, and CD19+ cells. Secondly, compared with group A, group C had higher levels of Fasting blood glucose (FBG), IL-6, TNF-α, and neutrophils but lower lymphocyte, CD3+ T cell, CD8+ T cell, and CD4+ T cell counts. Similarly, group D had higher FBG, IL-6 and TNF-α levels and lower lymphocyte, CD3+ T cell, CD8+ T cell, and CD4+ T cell counts than group B. Thirdly, binary logistic regression analysis showed that HbA1c, IL-6, and lymphocyte count were risk factors for the severity of COVID-19 with T2DM. Importantly, COVID-19 patients with T2DM were more likely to worsen from moderate to severe COVID-19 than nondiabetic patients. Of note, lymphopenia and inflammatory responses remained more severe throughout hospitalization for COVID-19 patients with T2DM. CONCLUSION: Our data suggested that COVID-19 patients with T2DM are more likely to develop severe COVID-19 than those without T2DM and that hyperglycemia associated with the lymphopenia and inflammatory responses in COVID-19 patients with T2DM.

Clinical and demographic characteristics of patients with COVID-19 infection: Statistics from a single hospital in Iran.

Coronavirus disease 2019 (COVID-19) has caused a global pandemic in early 2020. This infectious disorder has a heterogeneous course ranging from asymptomatic disorder to a critical situation needing intensive cares. In the current study, we present a report of affected patients admitted in a single hospital in Iran. Eighty-two hospitalized patients with COVID-19 were assessed. Demographic, clinical, and paraclinical parameters were gathered and statistically analyzed. The median age (IQR) of the patients was 57.32 (45.75, 70) years. At primary evaluation, fever was present in 45.12% of the affected individuals. The most common clinical symptoms were dyspnea (81.71%) and cough (65.85%). Totally, 12 (14.63%) and 14 (17.07%) of patients had low and high WBC counts, respectively. Lymphopenia was detected in 36 (43.9%) of patients, while 6 (7.32%) of patients had lymphocytosis. High levels of Il-6 were detected in 4 (4.88%) of patients. CRP levels were elevated in 69 (84.1%) of patients. The median (IQR) of hospitalization was 7 (5, 9) days. Totally, 26 patients (31%) were hospitalized in ICU. All patients were discharged with good health conditions except for one patient who died. The current study shows the heterogeneous clinical manifestations and paraclinical parameters of COVID-19 patients.

Deficiency of Tfh Cells and Germinal Center in Deceased COVID-19 Patients.

The COVID-19 pandemic caused by SARS-CoV2 is characterized by a remarkable variation in clinical severity ranging from a mild illness to a fatal multi-organ disease. Understanding the dysregulated human immune responses in the fatal subjects is critical for management of COVID-19 patients and the pandemic. In this study, we examined the immune cell compositions in the lung tissues and hilar lymph nodes using immunohistochemistry on 6 deceased COVID-19 patients and 4 focal organizing pneumonia (FOP) patients who underwent lung surgery and served as controls. We found a dominant presence of macrophages and a general deficiency of T cells and B cells in the lung tissues from deceased COVID-19 patients. In contrast to the FOP patients, Tfh cells and germinal center formation were largely absent in the draining hilar lymph nodes in the deceased COVID-19 patients. This was correlated with reduced IgM and IgG levels compared to convalescent COVID-19 patients. In summary, our data highlight a defect of germinal center structure in deceased COVID-19 patients leading to an impaired humoral immunity. Understanding the mechanisms of this deficiency will be one of the key points for the management of this epidemic.

Coronavirus Disease 2019 (COVID-19): A Haematologist's Perspective.

Coronavirus disease 2019 (COVID-19) is affecting millions of patients worldwide. It is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which belongs to the family Coronaviridae, with 80% genomic similarities to SARS-CoV. Lymphopenia was commonly seen in infected patients and has a correlation to disease severity. Thrombocytopenia, coagulation abnormalities, and disseminated intravascular coagulation were observed in COVID-19 patients, especially those with critical illness and non-survivors. This pandemic has caused disruption in communities and hospital services, as well as straining blood product supply, affecting chemotherapy treatment and haematopoietic stem cell transplantation schedule. In this article, we review the haematological manifestations of the disease and its implication on the management of patients with haematological disorders.

Hematological manifestations of COVID-19.

The emergence of the Coronavirus Disease -19 (COVID-19) pandemic, has had a tremendous global impact, resulting in substantial morbidity and mortality worldwide and especially in the United States, where nearly one third of the cases are located. Although involvement of the lower respiratory track accounts for most of the morbidity and mortality seen, the virus involves several organ systems and the syndrome exhibits clinical diversity with a wide range of symptoms and manifestations. The involvement of elements of the hematopoietic system is prominent in severe cases and associated with poor outcomes and mortality. Lymphopenia, leukopenia, thrombocytopenia, disseminated intravascular coagulation, and a prothrombotic state are common manifestations of COVID-19 and have important treatment and prognostic implications. Better understanding of the mechanisms of the pathophysiology of COVID-19-induced hematological abnormalities may ultimately result in better ways to treat them and decrease the associated morbidity and mortality.

Predictive factors of mortality in patients treated with tocilizumab for acute respiratory distress syndrome related to coronavirus disease 2019 (COVID-19).

COVID-19 patients (n = 34) suffering from ARDS were treated with tocilizumab (TCZ). Outcome was classified in two groups: "Death" and "Recovery". Predictive factors of mortality were studied. Mean age was 75.3, mean oxygen (O2) requirements 10.4 l/min. At baseline, all patients had multiple biological abnormalities (lymphopenia, increased CRP, ferritin, fibrinogen, D-dimer and liver enzymes). 24 patients (70.5%) recovered after TCZ therapy and 10 died (29.5%). Deceased subjects differed from patients in whom treatment was effective with regard to more pronounced lymphopenia (0.6 vs 1.0 G/l; p = 0.037), lower platelet number (156 vs 314 G/l; p = 0.0001), lower fibrinogen serum level (0.6 vs 1.0 G/l; p = 0.03), higher aspartate-amino-transferase (108 vs 57 UI/l; p = 0.05) and greater O2 requirements (11 vs 8 l/min; p = 0.003).

Do sex-specific immunobiological factors and differences in angiotensin converting enzyme 2 (ACE2) expression explain increased severity and mortality of COVID-19 in males?

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome (SARS) coronavirus 2 (SARS-CoV-2), shares similarities with the former SARS outbreak, which was caused by SARS-CoV-1. SARS was characterized by severe lung injury due to virus-induced cytopathic effects and dysregulated hyperinflammatory state. COVID-19 has a higher mortality rate in men both inside and outside China. In this opinion paper, we describe how sex-specific immunobiological factors and differences in angiotensin converting enzyme 2 (ACE2) expression may explain the increased severity and mortality of COVID-19 in males. We highlight that immunomodulatory treatment must be tailored to the underlying immunobiology at different stages of disease. Moreover, by investigating sex-based immunobiological differences, we may enhance our understanding of COVID-19 pathophysiology and facilitate improved immunomodulatory strategies.

Selective CD8 cell reduction by SARS-CoV-2 is associated with a worse prognosis and systemic inflammation in COVID-19 patients.

The lymphopenia exhibited in patients with COVID-19 has been associated with a worse prognosis in the development of the disease. To understand the factors associated with a worse evolution of COVID-19, we analyzed comorbidities, indicators of inflammation such as CRP and the ratio of neutrophils/lymphocytes, as well as the count of blood cells with T-lymphocyte subtypes in 172 hospitalized patients with COVID-19 pneumonia. Patients were grouped according to their needs for mechanical ventilation (ICU care) or not. Within the comorbidities studied, obesity was the only associated with greater severity and ICU admission. Both the percentage and the absolute number of neutrophils were higher in patients needing ICU care than non-ICU patients, whereas absolute lymphocyte count, and especially the percentage of lymphocytes, presented a deep decline in critical patients. There was no difference between the two groups of patients for CD4 T-lymphocytes, neither in percentage of lymphocyte nor in absolute number, however for CD8 T-cells the differences were significant for both parameters which were in decline in ICU patients. There was a firm correlation between the highest values of inflammation indicators with the decrease in percentage of CD8 T-lymphocytes. This effect was not seen with CD4 cells. Obesity together with lymphopenia, especially whether preferentially affects to CD8 T- lymphocytes, are factors that can predict a poor prognosis in patients with COVID-19.

Lymphopenia that may develop in patients treated with temozolomide and immune control check-point inhibitor may be a high risk for mortality during the COVID-19 outbreak.

As we know more about the clinical and laboratory features of COVID-19, which is now accepted as a pandemic, many questions have been raised about how to manage and monitor the treatment of cancer patients. It was determined that the incidence of lymphopenia increased in COVID-19 and there was a significant relationship between lymphopenia and mortality. This can be thought of as an unresponsive problem in how to maintain anti-cancer drugs that cause lymphopenia. This article was written for a hypothetical approach in cancer patients diagnosed with COVID-19 in order to be an idea of collecting data for treatment with anti-cancer drugs that cause lymphopenia.