Early Short-Term Use of Different Doses of Corticosteroid in Hospitalized Pediatric Patients with Coronavirus Disease 2019 Pneumonia

Objective Encouraged by reports of favorable outcomes following the use of corticosteroids in patients with moderate-to-severe coronavirus 2019 (COVID-19) pneumonia, we aimed to present our experience with early short-term corticosteroid use at our center in pediatric patients with COVID-19 pneumonia. Methods One hundred and twenty-nine pediatric patients were included in the study. Patients were divided into four groups according to the type and dose of corticosteroids given: Group 1 (those receiving dexamethasone 0.15 mg/kg/d);Group 2 (those receiving methylprednisolone 1 mg/kg/d);Group 3 (those receiving methylprednisolone 2 mg/kg/d);and Group 4 (those receiving pulse methylprednisolone 10-30 mg/kg/d). Results Of 129 patients, 19 (14.7%) patients were assigned to Group 1, 30 (23.3%) patients to Group 2, 30 (23.3%) patients to Group 3, and 50 (38.8%) patients to Group 4. Thirty-two (24.8%) patients were followed in the pediatric intensive care unit (PICU), of whom 13 (10%) required mechanical ventilation, and 7 (%5.4) died. In Group 4, the hospitalization length was significantly longer than in other groups (p < 0.001, p < 0.001). No significant difference was found among the groups in terms of mortality (p = 0.15). The most common comorbidity was obesity (33%). A significant association was found between the presence of comorbidity and mortality (p < 0.001). All patients who died had an underlying disease. Cerebral palsy was the most common underlying disease among the patients who died. Worsening of lymphopenia was significant in patients with severe COVID-19 pneumonia at the time of transfer to the PICU (p = 0.011). Conclusion Although children usually have a milder course of COVID-19 than adults, underlying diseases and obesity increase the severity of disease manifestations also in children. Further studies are needed to define the exact role of corticosteroids in COVID-19 patients. © 2022. Thieme. All rights reserved.

Kinetics of Immune Subsets in COVID-19 Patients Treated with Corticosteroids.

RATIONALE: Changes in anti-SARS-CoV-2 defense immune subsets in patients treated with dexamethasone (DXM) for severe COVID-19 and their relation to disease outcomes are poorly understood. METHODS: Blood-lymphocyte subsets of 110 hospitalized COVID-19 patients were prospectively examined. A first sample was taken at enrollment and a second one 7-10 days later. Total B-, T-lymphocytes, CD4+, CD8+, T-regulatory (Treg), Natural-Killer (NK) and NK T-cells were counted using flow cytometry. RESULTS: At enrollment, patients with respiratory failure, characterized by DXM failure (intubation/death) or DXM success (hospital discharge) exhibited significantly fewer CD3+, CD4+ and CD8+ cells and B-lymphocytes compared to the control group (no respiratory failure/no DXM). At the time of treatment completion, the DXM-failure group exhibited significantly fewer CD3+, CD4+ and CD8+ cells, memory CD4+ and CD8+ T-lymphocytes, compared to the control and the DXM-success groups and fewer activated CD4+ T-lymphocytes, Tregs and NK cells compared to the control group. At the time of treatment completion, the number of all investigated lymphocyte subsets increased in the DXM-success group and was similar to those of the control group. NK cells significantly decreased over time in the DXM-failure group. CONCLUSION: The lymphocyte kinetics differ between DXM-treated and control COVID-19 patients and are associated with clinical outcomes.

COVID-19 and T Cells: Do T Cells Really Matter?

How to cite this article: Gajjala C, Jindal, A. COVID-19 and T Cells: Do T Cells Really Matter? Indian J Crit Care Med 2023;27(1):75.

A Pilot Trial of Thymalfasin (Tα1) to Treat Hospitalized Patients with Hypoxemia and Lymphocytopenia due to COVID-19 Infection.

BACKGROUND: Thymosin-α-1 (Tα1) may be a treatment option for COVID-19, but efficacy and safety data remain limited. METHODS: Prospective, open-label, randomized trial assessing preliminary efficacy and safety of thymalfasin (synthetic form of Tα1), compared with standard of care, among hospitalized patients with hypoxemia and lymphocytopenia due to COVID-19. RESULTS: 49 patients were included in this analysis. Compared with control patients, the incidence of clinical recovery was higher for treated patients with either baseline low flow oxygen (subdistribution hazard ratio [SHR]: 1.48; 95% CI: 0.68-3.25) or baseline high flow oxygen (SHR: 1.28; 95% CI: 0.35-4.63), although neither were significant. Among patients with baseline low flow oxygen, treated patients, compared with control patients, had an average difference of 3.84 times more CD4+ T cells on Day 5 than on Day 1 (p = 0.0113). Nine serious adverse events among treated patients were deemed not related to Tα1. CONCLUSION: Tα1 increases CD4+ T cell count among patients with baseline low flow oxygen support faster than standard of care and may have a role in the management of hospitalized patients with hypoxemia and lymphocytopenia due to COVID-19.

COVID-19 Severity, Cardiological Outcome, and Immunogenicity of mRNA Vaccine on Adult Patients With 22q11.2 DS.

BACKGROUND: The contemporaneous presence of immune defects and heart diseases in patients with 22q11.2 deletion syndrome (22q11.3DS) might represent risk factors for severe coronavirus 2019 disease (COVID-19). OBJECTIVE: To analyze severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outcome in 22q11.2DS patients and immunogenicity of different doses of mRNA SARS-CoV-2 vaccine. METHODS: Longitudinal observational study on SARS-CoV-2 outcome in 60 adults with 22q11.2DS (March 2020-June 2022). Anti-Spike, and anti-receptor binding domain (RBD) antibody responses, generation of Spike-specific memory B cells (MBCs) and Spike-specific T cells at different time points before and after the mRNA BNT162b2 vaccination were evaluated in 16 22q11.2DS patients. RESULTS: We recorded a 95% rate of vaccination, with almost all patients being immunized with the booster dose. Twenty-one patients had SARS-CoV-2 infection. Three patients were infected before vaccine availability, 6 after receiving 2 doses of vaccine, and 12 after one booster dose. The SARS-CoV-2- infection had a mild course, except in one unvaccinated patient with several comorbidities who died from acute respiratory distress syndrome (fatality rate 5%). Infected patients had more frequently moderate/severe intellectual disability, lymphopenia, and lower CD4+ count. Despite major congenital heart diseases, COVID-19 did not impact cardiological conditions. The BNT162b2 vaccine induced S1-immunoglobulin G (IgG) responses, low serum S1-IgA, and slightly impaired specific MBCs response. Specific T-cell responses observed were related to lymphocytes and CD4+ T cell counts. CONCLUSIONS: The SARS-CoV-2 infection had a mild course in most patients with 22q11.2DS, even in patients with major cardiovascular diseases. Immunization induced Spike-specific IgG responses and generated specific MBCs and memory T cells. The weaker memory responses in patients with lymphopenia suggested the need for additional doses.

Effect of Thymalfasin (Thymosin-α-1) on Reversing Lymphocytopenia among Patients with COVID-19

Introduction Thymosin-α-1 (Tα1) elevates lymphocyte counts among patients with COVID-19, but its effect on reversing lymphocytopenia is unknown. Methods 24 patients treated with Tα1 and 100 patients in the control arm were included in this analysis. The incidence rate of reversing lymphocytopenia, overall and stratified by baseline oxygen support, above the threshold for classification of lymphocytopenia (i.e., Total Lymphocyte Count (TLC) < 1.5 x 109/L) and severe lymphocytopenia (i.e., TLC < 1.0 x 109/L) within 3, 5, and 7 days of treatment initiation was calculated, along with incidence rate ratios (IRRs) and 95% confidence intervals (CIs). Results Compared with the standard of care, the rate of reversing lymphocytopenia (IRR: 2.38, 95% CI: 0.92 – 5.81) and severe lymphocytopenia (IRR: 1.57, 95% CI: 0.59 – 3.72), especially among patients with severe lymphocytopenia on high flow oxygen support (IRR: 3.64, 95% CI: 0.71 – 23.44), was greater for patients treated with Tα1 within 3 days of treatment initiation, although analyses were not significant. Conclusion Among patients with hypoxemia and lymphocytopenia, Tα1 may reverse lymphocytopenia and severe lymphocytopenia, particularly within 3 days of treatment initiation, faster than the standard of care.

Upregulation of PD-L1 by SARS-CoV-2 promotes immune evasion.

Patients with severe COVID-19 often suffer from lymphopenia, which is linked to T-cell sequestration, cytokine storm, and mortality. However, it remains largely unknown how severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) induces lymphopenia. Here, we studied the transcriptomic profile and epigenomic alterations involved in cytokine production by SARS-CoV-2-infected cells. We adopted a reverse time-order gene coexpression network approach to analyze time-series RNA-sequencing data, revealing epigenetic modifications at the late stage of viral egress. Furthermore, we identified SARS-CoV-2-activated nuclear factor-κB (NF-κB) and interferon regulatory factor 1 (IRF1) pathways contributing to viral infection and COVID-19 severity through epigenetic analysis of H3K4me3 chromatin immunoprecipitation sequencing. Cross-referencing our transcriptomic and epigenomic data sets revealed that coupling NF-κB and IRF1 pathways mediate programmed death ligand-1 (PD-L1) immunosuppressive programs. Interestingly, we observed higher PD-L1 expression in Omicron-infected cells than SARS-CoV-2 infected cells. Blocking PD-L1 at an early stage of virally-infected AAV-hACE2 mice significantly recovered lymphocyte counts and lowered inflammatory cytokine levels. Our findings indicate that targeting the SARS-CoV-2-mediated NF-κB and IRF1-PD-L1 axis may represent an alternative strategy to reduce COVID-19 severity.

Do Laboratory Biomarkers Predict Survival In Severe Covid-19? A Cross-Sectional Study.

Background: This study aims to compare lymphocyte count, C-reactive protein (CRP), ferritin, Lactate Dehydrogenase (LDH) and D-dimer among survivors and non-survivors of severe COVID-19. Methods: This retrospective cross-sectional analytical study included 69 patients for whom a record of the biomarkers and survival status was available. Baseline and peak values were selected for serum CRP, ferritin, LDH and D-Dimer. Baseline and trough lymphocyte counts were selected. Data were analyzed using SPSS version 21. Mean and standard deviation were used to compare the biomarkers with paired t-test. p-value <0.05 was taken as significant. Results: The mean age of the study population was 55.5±9.1 years and 50 (72.5%) were male. Among survivors, the increase in CRP level was not significant (from 15.80±9.8 mg/dl to 17.87±8.4 mg/dl, p=0.45) while it was significant in non-survivors (from 16.68±10.90 mg/dl to 20.77±12.69 mg/dl, p=0.04). There was no significant rise in LDH levels in survivors (from 829.59±499 U/L to 1018.6±468 U/L, p=0.20) while it increased significantly in non-survivors (from 816.2±443.08 U/L to 1056.61±480.54 U/L, p=0.003). The decrease in lymphocyte count and increase in D-Dimers in both the groups was significant (p=0.001). There was no significant elevation in ferritin in both the groups (p>0.05). Conclusion: In severe COVID-19 patients, serum CRP and LDH can be used for risk stratification and predicting survival. Lymphopenia, increase in serum ferritin and D-dimers may not predict survival.

Specific Clinical and Immunological Changes Following Mesenchymal Stem Cell Transplantation in COVID-19-induced Acute Respiratory Distress Syndrome Patients: A Phase-I Clinical Trial.

Acute respiratory distress syndrome (ARDS) is a systemic inflammation resulting from immune system overactivity. ARDS is also a fatal complication of COVID-19. Mesenchymal stem cells (MSCs) have immune modulatory properties. This study evaluated the safety and efficacy of three times transplantation of umbilical cord-derived MSCs (UC-MSCs) in terms of specific immunological and clinical changes in mild-to-moderate COVID-19-induced ARDS patients. In this single-center, open-label, phase 1 clinical trial, 20 patients diagnosed with COVID-19 and mild-to-moderate ARDS were included and were divided into two groups: a control group receiving standard care and an intervention group receiving UC-MSC in addition to standard care. Three consecutive intravenous transplants of UC-MSC (1×  cells/kg body weight per each transplant) were performed in the intervention group on days 1, 3, and 5. The biological assay was investigated four times (days 0, 5, 10, and 17). UC-MSCs improved the patients' clinical and paraclinical parameters, including leukocytosis, lymphopenia, thrombocytopenia, and liver enzyme abnormalities compared to the control group. They also decreased pro-inflammatory lymphocytes (TH1 and TH17) and increased anti-inflammatory T lymphocytes. Cell therapy also reduced the mean fluorescence intensity (MFI) in overactivated CD8+ T cells.  These findings show that three UC-MSC injections could regulate a hyperactivated immune system in COVID-19-induced ARDS patients by decreasing the inflammatory T lymphocyte subset and can improve the patient's hematological condition and liver function. However, more studies are needed in this area.

Haematological changes in sailors who had COVID-19.

BACKGROUND: Follow-up of patients who had coronavirus disease 2019 (COVID-19) proves that clinical symptoms persist for months after recovery. A complex of such persistent manifestations is defined as the post-COVID-19 syndrome. One of the criteria for post-COVID-19 syndrome may be typical changes in white blood cell count and white blood cell (WBC) differential. The aim of the work is to study the frequency of haematological changes in sailors who had the acute coronavirus infection. MATERIALS AND METHODS: The retrospective study covered 30 candidate sailors aged 21 to 60 years with a history of COVID-19 and persistent changes in the WBC count and WBC differential and who did not have haematological abnormalities during the previous medical examinations. RESULTS: Analysis of WBC and WBC count at the long-term period after COVID-19 confirmed persistent changes in the form of neutrophilia, lymphopenia, changes in the neutrophils and lymphocytes ratio. The revealed changes in the WBC count were typical and fit into several patterns: A. Absolute leukocytosis, absolute and relative neutrophilia, relative lymphopenia; B. Relative and absolute lymphopenia, relative neutrophilia; C. Relative and absolute lymphocytosis, relative neutropenia; D. Relative lymphopenia, without other changes in WBC differential. CONCLUSIONS: The most typical laboratory change in WBC count in patients with the past COVID-19 is relative or absolute leukopenia. Persistent changes in WBC count are not always outside of the reference range for absolute values and should be assessed by a complex of typical changes. The presence of typical changes in WBC count in a patient with the past COVID-19 requires a profound examination for the post-COVID-19 syndrome.

Clinical Investigation of Leukocyte DNA Damage in COVID-19 Patients.

This prospective cross-sectional study aimed to evaluate leukocyte DNA damage in coronavirus disease (COVID-19) patients. In this study, 50 COVID-19-positive patients attending the Erzurum City Hospital Internal Medicine Outpatient Clinic and 42 control group patients were included. DNA damage was detected in living cells through leukocyte isolation in 50 COVID-19-positive patients using the comet assay method. DNA tail/head (olive) moments were evaluated and compared. White blood cells (WBC), red blood cells (RBC), hemoglobin (HGB), neutrophils (NEU), lymphocytes (LYM), eosinophils (EO), monocytes (MONO), basophils (BASO), platelets (PLT), and the neutrophil/lymphocyte ratio (NLR) were analyzed. The RBC, lymphocyte, eosinophil, and monocyte means were significantly higher in the control group (p < 0.05), whereas the HGB and neutrophile means were significantly higher in the study group (p < 0.05). There were significant negative correlations between COVID-19 and RBC (r = -0.863), LYM (r = -0.542), EO (r = -0.686), and MONO (r = -0.385). Meanwhile, there were significant positive correlations between COVID-19 and HGB (r = 0.863), NEU (r = 0.307), tail moment (r = 0.598), and olive moment (r = 0.582). Both the tail and olive moment mean differences were significantly higher in the study group, with higher ranges (p < 0.05). COVID-19 infection caused statistically significant increases in both the tail and olive damage percentage in patients, causing DNA damage. Lastly, the NLR rate was associated with the presence and progression of COVID-19.

Angiotensin II induces reactive oxygen species, DNA damage, and T-cell apoptosis in severe COVID-19.

BACKGROUND: Lymphopenia is predictive of survival in patients with coronavirus disease 2019 (COVID-19). OBJECTIVE: The aim of this study was to understand the cause of the lymphocyte count drop in severe forms of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. METHODS: Monocytic production of reactive oxygen species (ROSs) and T-cell apoptosis were measured by flow cytometry, DNA damage in PBMCs was measured by immunofluorescence, and angiotensin II (AngII) was measured by ELISA in patients infected with SARS-CoV-2 at admission to an intensive care unit (ICU) (n = 29) or not admitted to an ICU (n = 29) and in age- and sex-matched healthy controls. RESULTS: We showed that the monocytes of certain patients with COVID-19 spontaneously released ROSs able to induce DNA damage and apoptosis in neighboring cells. Of note, high ROS production was predictive of death in ICU patients. Accordingly, in most patients, we observed the presence of DNA damage in up to 50% of their PBMCs and T-cell apoptosis. Moreover, the intensity of this DNA damage was linked to lymphopenia. SARS-CoV-2 is known to induce the internalization of its receptor, angiotensin-converting enzyme 2, which is a protease capable of catabolizing AngII. Accordingly, in certain patients with COVID-19 we observed high plasma levels of AngII. When looking for the stimulus responsible for their monocytic ROS production, we revealed that AngII triggers ROS production by monocytes via angiotensin receptor I. ROSs released by AngII-activated monocytes induced DNA damage and apoptosis in neighboring lymphocytes. CONCLUSION: We conclude that T-cell apoptosis provoked via DNA damage due to the release of monocytic ROSs could play a major role in COVID-19 pathogenesis.

Lymphopenia in sepsis-an acquired immunodeficiency?

Sepsis is a global health priority, yet effective host-directed targeted therapies have not been identified outside of the setting of COVID-19. Lymphopenia occurs in up to ~52% of patients with sepsis and is associated with a higher mortality at both 30 and 100 days. In COVID-19, the presence of lymphopenia correlates with intensive care unit (ICU) admission, acute respiratory distress syndrome (ARDS) and death. The mechanisms underpinning lymphopenic sepsis remain unknown, and while high rates of lymphocyte apoptosis have been implicated, the relative contributions of cellular trafficking to inflamed tissues and reduction in lymphopoiesis require investigation. Further delineation of these underlying mechanisms holds the potential to open new avenues for the development of host-directed therapies in lymphopenic sepsis. These may include recombinant cytokines (e.g. IL-7), monoclonal antibodies (e.g. anti-IL-1, anti-PD-1) and siRNA (e.g. targeting IL-10, TGFß). Applying the frontier tools of translational cellular and genomic medicine to understand lymphopenia in the setting of critical infections holds the potential to significantly reduce the excessive global burden of sepsis.