Lymphopenia an important immunological abnormality in patients with COVID-19: Possible mechanisms

A retrospective cohort study on the association between nutritional status and prognosis in COVID-19 patients with severe and critical infection

OBJECTIVE

To evaluate the relationship between nutritional scoring systems, nutritional support methods, and the prognosis of severe and critically ill patients infected with the Omicron variant of coronavirus disease 2019 (COVID-19).

METHODS

Patients with confirmed Omicron variant severe and critical COVID-19, who were admitted to Chongqing Medical University First Hospital between December 2022 and January 2023, were enrolled into this retrospective study. Clinical data of patients who survived for 28 days were compared with those who died during the same period. Nutritional status was assessed using the 2002 Nutrition Risk Screening (NRS) tool and Prognostic Nutritional Index (PNI). Factors influencing patient mortality were identified by multivariate logistic regression, and the relationship between patient nutrition and mortality as the disease progressed was illustrated using Kaplan-Meier curves. The study was registered on the ChiCTR platform (No. ChiCTR2300067595).

RESULTS

A total of 508 patients were included (349 survivors and 159 non-survivors). Significant differences were found in sex, age, NRS score, PNI score, albumin level, lymphocyte count, chronic comorbidities, mechanical ventilation, neutrophil count, procalcitonin, and platelet count between survivors and non-survivors. Multivariate analysis revealed that high NRS score (OR 3.87, 95% CI, 1.97, 7.63), fourth-level nutritional support (combined enteral and parenteral nutrition; OR 7.89, 95% CI, 1.32, 47.28), chronic comorbidities (OR 4.03, 95% CI, 1.91, 8.51), and mechanical ventilation (OR 6.03, 95% CI, 3, 12.13) were risk factors for mortality (OR > 1). The malnutrition rate among patients with NRS ≥ 3 was 41.93%. The median (interquartile range) PNI score was 38.20 (35.65, 41.25) for survivors versus 32.65 (29.65, 36.58) for non-survivors. The mortality rate was higher in patients with high nutritional risk within 28 days of hospitalization. The descending order for mortality rate in patients receiving different nutritional support was: dual parenteral and enteral nutrition, no nutritional intervention, single enteral nutrition, and single parenteral nutrition.

CONCLUSION

A high proportion of severe and critically ill patients with COVID-19 experience malnutrition, and various factors are associated with their prognosis. High nutritional risk is significantly related to patient mortality. Early assessment using NRS or PNI is crucial for these patients, and personalized interventions should be implemented to improve overall nutritional status, maintain organ function, and enhance the body's antiviral defence.

Angiotensin-(1-7) decreases inflammation and lung damage caused by betacoronavirus infection in mice

OBJECTIVE

Pro-resolving molecules, including the peptide Angiotensin-(1-7) [Ang-(1-7)], have potential adjunctive therapy for infections. Here we evaluate the actions of Ang-(1-7) in betacoronavirus infection in mice.

METHODS

C57BL/6J mice were infected intranasally with the murine betacoronavirus MHV-3 and K18-hACE2 mice were infected with SARS-CoV-2. Mice were treated with Ang-(1-7) (30 µg/mouse, i.p.) at 24-, 36-, and 48-hours post-infection (hpi) or at 24, 36, 48, 72, and 96 h. For lethality evaluation, one additional dose of Ang-(1-7) was given at 120 hpi. At 3- and 5-days post- infection (dpi) blood cells, inflammatory mediators, viral loads, and lung histopathology were evaluated.

RESULTS

Ang-(1-7) rescued lymphopenia in MHV-infected mice, and decreased airways leukocyte infiltration and lung damage at 3- and 5-dpi. The levels of pro-inflammatory cytokines and virus titers in lung and plasma were decreased by Ang-(1-7) during MHV infection. Ang-(1-7) improved lung function and increased survival rates in MHV-infected mice. Notably, Ang-(1-7) treatment during SARS-CoV-2 infection restored blood lymphocytes to baseline, decreased weight loss, virus titters and levels of inflammatory cytokines, resulting in improvement of pulmonary damage, clinical scores and lethality rates.

CONCLUSION

Ang-(1-7) protected mice from lung damage and death during betacoronavirus infections by modulating inflammation, hematological parameters and enhancing viral clearance.

Immunomodulatory effect of IFN-γ licensed adipose-mesenchymal stromal cells in an in vitro model of inflammation generated by SARS-CoV-2 antigens

In recent years, clinical studies have shown positive results of the application of Mesenchymal Stromal Cells (MSCs) in severe cases of COVID-19. However, the mechanisms of immunomodulation of IFN-γ licensed MSCs in SARS-CoV-2 infection are only partially understood. In this study, we first tested the effect of IFN-γ licensing in the MSC immunomodulatory profile. Then, we established an in vitro model of inflammation by exposing Calu-3 lung cells to SARS-CoV-2 nucleocapsid and spike (NS) antigens, and determined the toxicity of SARS-CoV-2 NS antigen and/or IFN-γ stimulation to Calu-3. The conditioned medium (iCM) generated by Calu-3 cells exposed to IFN-γ and SARS-CoV-2 NS antigens was used to stimulate T-cells, which were then co-cultured with IFN-γ-licensed MSCs. The exposure to IFN-γ and SARS-CoV-2 NS antigens compromised the viability of Calu-3 cells and induced the expression of the inflammatory mediators ICAM-1, CXCL-10, and IFN-β by these cells. Importantly, despite initially stimulating T-cell activation, IFN-γ-licensed MSCs dramatically reduced IL-6 and IL-10 levels secreted by T-cells exposed to NS antigens and iCM. Moreover, IFN-γ-licensed MSCs were able to significantly inhibit T-cell apoptosis induced by SARS-CoV-2 NS antigens. Taken together, our data show that, in addition to reducing the level of critical cytokines in COVID-19, IFN-γ-licensed MSCs protect T-cells from SARS-CoV-2 antigen-induced apoptosis. Such observations suggest that MSCs may contribute to COVID-19 management by preventing the lymphopenia and immunodeficiency observed in critical cases of the disease.

Immuno-inflammatory and organ dysfunction markers in severe COVID-19 patients

Infection with the SARS-CoV-2 virus may induce some complications among people who experience mild to moderate respiratory illness and some of them recover without requiring special treatment. Albeit, some individuals become seriously reached risk points and require special medical attention especially older people and people who suffer from chronic diseases. Serum and whole blood samples were collected from confirmed infected persons with SARS CoV-2 by real-time PCR and the control group. All lab. Investigations were performed using Cobas 6000. Significant differences were noted between patients compared to the control group in the Mean ± SD of IL-6 (76.06 ± 7.60 vs 3.61 ± 0.296 pg/ml), Procalcitonin (0.947 ± 0.117 vs 0.061 ± 0.007 ng/ml), CRP (125.3 ± 7.560 vs 4.027 ± 0.251 mg/dl), ALT (154.8 ± 30.47 vs 49.75 ± 2.977 IU/L) and AST (70.83 ± 9.215 vs 27.23 ± 1.767) respectively. While other parameters were also showed significant differences were noted between patients compared to the control group for D-Dimmer, PT, PTT, LDH, Ferritin, WBC, Lymphocyte and Creatinine. The results reached that the effect of SARS CoV-2 and cytokine storm was clear on the body's organs through vital biomarker investigations that were performed in this study.

Outcomes of COVID-19 in 24 hospitalized liver transplant recipients: an observational study

BACKGROUND

Although liver transplant (LT) recipients are considered a population at risk of severe features of coronavirus disease 2019 (COVID-19), data in this regard are scarce and controversial. In this study, we reported the outcome of 24 cases of LT recipients who were hospitalized due to COVID-19 and investigated the role-playing factors in the severity of the disease.

METHODS

In this single-center, analytic case-series study, eligible patients were among LT recipients who were hospitalized due to the diagnosis of COVID-19 based on positive results of polymerase chain reaction. Participants were categorized as severe COVID-19 if they were admitted to the intensive care unit, experienced respiratory failure demanding mechanical ventilation, or eventually died. Demographic and clinical data, COVID-19 symptoms and specific treatments, laboratory biomarkers, and immunosuppressive regimens and their alteration during the admission were recorded. Analysis was done using SPSS software.

RESULTS

Twenty-four hospitalized LT patients were included, of which nine had severe and fifteen had non-severe COVID-19. Out of 9 patients with severe COVID-19, four sadly died. The analysis and comparison between the two groups revealed longer hospital stays (P = 0.02), lower lymphocyte counts (P = 0.002), and higher levels of C-reactive protein (CRP) (P = 0.006) in patients with severe COVID-19. Patients with non-severe COVID-19 had higher doses of tacrolimus and mycophenolate in their baseline immunosuppressive regimen (both P = 0.02).

CONCLUSION

Lymphopenia and high CRP levels are associated with more severe forms of COVID-19 in LT patients. Mycophenolate may have protective properties against severe COVID-19. The role of severity indicators in LT patients with COVID-19 needs to be systematically recognized.

The Impact of Severe COVID-19 on Corneal Endothelial Cells-Analysis of the In Vivo Noncontact Specular Microscopy

PURPOSE

This study aimed to investigate the effects of severe COVID-19 infection on the corneal endothelium via in vivo specular microscopy.

METHODS

This was an observational, prospective, and controlled study including 56 eyes of 56 severe COVID-19 patients, compared to after-recovery and 56 eyes of 56 age- and gender-matched healthy controls.

RESULTS

Endothelial cell density was lower in the active disease period compared to healthy controls (p = .001) and decreased even more after recovery (p < .0001). After recovery, the average cell area and coefficient of variation were higher compared to the active disease period (p < .0001 and p = .008, respectively) and the healthy controls (for both, p < .0001), whereas hexagonality was lower (p < .0001). Central corneal thickness increased in the active disease period compared to after recovery (p < .0001) and healthy controls (p = .002).

CONCLUSIONS

These results may be due to direct host-virus interaction or linked to immune dysregulation, subclinical corneal endotheliitis, or still yet a viral-mediated inflammation.

A cross-sectional study on clinical characteristics and severity of children with COVID-19 admitted to a teaching institute in North India

Background

SARS-CoV-2 infection presentation in children is usually milder than in adults but can be severe and fatal as well. Data on the pediatric population regarding severity and clinical presentation are still limited, and there is a need to have a better understanding of clinical features, severity, and laboratory parameters.

Aims and Objective

To document clinical and laboratory characteristics and outcomes of children with SARS-CoV-2 in a low-middle-income country and to evaluate clinicodemographic factors and biochemical markers associated with severity and mortality.

Materials and Methods

A hospital-based cross-sectional study was conducted among 112 COVID-19-positive children at a designated Level-3 center in North India. Clinical characteristics, laboratory parameters, and severity of COVID-19 cases as well as factors associated with the severity of the disease, were analyzed by descriptive statistics and a Chi-square test.

Results

The adolescent age group (age 12-18 years) was affected most (64.3%). Male patients accounted for 56.3% of total cases. Fever was the most common symptom (41.1%) followed by cough. Presenting complaints were highest from the respiratory system (32.1%) followed by the gastrointestinal (8.9%) and the neurological system (7.1%). Majority of patients had mild disease (87%) while 13% had the moderate-severe disease. Spo2 < 95% (P = 0.00001), neutrophilia (P < 0.000001), lymphopenia (P < 0.000001), elevated values of C-reactive protein (P < 0.00001), Interleukin-6 (P = 0.002), D- dimer (P = 0.00014) and respiratory symptoms as presenting complaints (P < 0.000001) were found to be significantly associated with severity of disease.

Conclusion

The male and adolescent age group was affected most. Presenting complaints were highest from the respiratory system. Unusual presentation may have gastrointestinal or neurological presentation. Most children with COVID-19 had mild disease. Moderate to severe disease was not uncommon. Factors including neutrophilia, lymphopenia, elevated lab values of C-reactive protein, D-dimer, and interleukin-6 had a significant association with the severity of the disease. These biomarkers can help predict the severity of the disease.

Review of clinical characteristics and mortality outcomes in patients on maintenance hemodialysis during the Omicron surge: a single center experience

BACKGROUND

This hemodialysis center experienced the pandemic from December 2022 to January 2023. Therefore, we sought to describe the clinical characteristics and mortality outcomes in hemodialysis patients during this Omicron surge.

METHODS

According to whether they are infected, they are divided into two groups: SARS-CoV-2-positive and SARS-CoV-2-negative. The SARS-CoV-2-positive group was divided into a survival group and a non-survival group for comparison.

RESULTS

366 of 457 hemodialysis patients were infected with SARS-CoV-2. The most common symptoms observed were fever (43.2%) and cough (29.8%), Followed by diarrhea (1.4%). Hemodialysis patients with hypertension were more susceptible to SARS-CoV-2 infection. The lymphocyte count, serum creatinine, serum potassium, and serum phosphorus in the SARS-CoV-2-positive group were significantly lower than those in the SARS-CoV-2-negative group. The all-cause mortality rate for infection with SARS-CoV-2 was 5.2%. Only 7 of 366 SARS-CoV-2-positive patients were admitted to the intensive care unit, but 6 of them died. Intensive care unit hospitalization rates were significantly higher in the non-survival group compared with the survival group. White blood cells count, neutrophil count, C-reactive protein, AST, and D-dimer in the non-survival group were higher than those in the survival group. The lymphocyte count, hemoglobin concentration, serum creatinine, serum albumin, serum phosphorus and parathyroid hormone in the non-survival group were lower than those in the survival group. Age > 65 years, elevated C-reactive protein and AST are independent risk factors for death. Finally, no significant difference in vaccination status was found between the SARS-CoV-2-positive group and the negative group.

CONCLUSIONS

Hemodialysis patients are at high risk for SARS-CoV-2 infection. Ensuring the adequacy of hemodialysis treatment and maintaining good physical condition of patients are the top priorities.

Acquired Immune Deficiency Syndrome correlation with SARS-CoV-2 N genotypes

BACKGROUND

Epigenetics and clinical observations referring to Betacoronavirus lead to the conjecture that Sarbecovirus may have the ability to infect lymphocytes using a different way than the spike protein. In addition to inducing the death of lymphocytes, thus drastically reducing their population and causing a serious immune deficiency, allows it to remain hidden for long periods of latency using them as a viral reservoir in what is named Long-Covid Disease. Exploring possibilities, the hypothesis is focused on that N protein may be the key of infecting lymphocytes.

METHOD

The present article exhibits a computational assay for the latest complete sequences reported to GISAID, correlating N genotypes with an enhancement in the affinity of the complex that causes immune deficiency in order to determine a good docking with the N protein and some receptors in lymphocytes.

RESULTS

A novel high-interaction coupling of N-RBD and CD147 is presented as the main way of infecting lymphocytes, allowing to define those genotypes involved in their affinity enhancement.

CONCLUSION

The hypothesis is consistent with the mutagenic deriving observed on the in-silico assay, which reveals that genotypes N/120 and N/152 are determinant to reduce the Immune Response of the host infecting lymphocytes, allowing the virus persists indefinitely and causing an Acquire Immune Deficiency Syndrome.

Innate Immunity in Protection and Pathogenesis During Coronavirus Infections and COVID-19

The COVID-19 pandemic was caused by the recently emerged β-coronavirus SARS-CoV-2. SARS-CoV-2 has had a catastrophic impact, resulting in nearly 7 million fatalities worldwide to date. The innate immune system is the first line of defense against infections, including the detection and response to SARS-CoV-2. Here, we discuss the innate immune mechanisms that sense coronaviruses, with a focus on SARS-CoV-2 infection and how these protective responses can become detrimental in severe cases of COVID-19, contributing to cytokine storm, inflammation, long-COVID, and other complications. We also highlight the complex cross talk among cytokines and the cellular components of the innate immune system, which can aid in viral clearance but also contribute to inflammatory cell death, cytokine storm, and organ damage in severe COVID-19 pathogenesis. Furthermore, we discuss how SARS-CoV-2 evades key protective innate immune mechanisms to enhance its virulence and pathogenicity, as well as how innate immunity can be therapeutically targeted as part of the vaccination and treatment strategy. Overall, we highlight how a comprehensive understanding of innate immune mechanisms has been crucial in the fight against SARS-CoV-2 infections and the development of novel host-directed immunotherapeutic strategies for various diseases.

Severe pediatric COVID-19: a review from the clinical and immunopathophysiological perspectives

BACKGROUND

Coronavirus disease 2019 (COVID-19) tends to have mild presentations in children. However, severe and critical cases do arise in the pediatric population with debilitating systemic impacts and can be fatal at times, meriting further attention from clinicians. Meanwhile, the intricate interactions between the pathogen virulence factors and host defense mechanisms are believed to play indispensable roles in severe COVID-19 pathophysiology but remain incompletely understood.

DATA SOURCES

A comprehensive literature review was conducted for pertinent publications by reviewers independently using the PubMed, Embase, and Wanfang databases. Searched keywords included "COVID-19 in children", "severe pediatric COVID-19", and "critical illness in children with COVID-19".

RESULTS

Risks of developing severe COVID-19 in children escalate with increasing numbers of co-morbidities and an unvaccinated status. Acute respiratory distress stress and necrotizing pneumonia are prominent pulmonary manifestations, while various forms of cardiovascular and neurological involvement may also be seen. Multiple immunological processes are implicated in the host response to COVID-19 including the type I interferon and inflammasome pathways, whose dysregulation in severe and critical diseases translates into adverse clinical manifestations. Multisystem inflammatory syndrome in children (MIS-C), a potentially life-threatening immune-mediated condition chronologically associated with COVID-19 exposure, denotes another scientific and clinical conundrum that exemplifies the complexity of pediatric immunity. Despite the considerable dissimilarities between the pediatric and adult immune systems, clinical trials dedicated to children are lacking and current management recommendations are largely adapted from adult guidelines.

CONCLUSIONS

Severe pediatric COVID-19 can affect multiple organ systems. The dysregulated immune pathways in severe COVID-19 shape the disease course, epitomize the vast functional diversity of the pediatric immune system and highlight the immunophenotypical differences between children and adults. Consequently, further research may be warranted to adequately address them in pediatric-specific clinical practice guidelines.

NBS superfood: a promising adjunctive therapy in critically ill ICU patients with omicron variant of COVID-19

This clinical trial aimed to assess the impact of Nutrition Bio-shield superfood (NBS) on clinical status among critically ill ICU patients suffering from acute respiratory distress syndrome (ARDS) due to the Omicron variant of COVID-19. A total of 400 patients with confirmed Omicron-related ARDS were randomly assigned to either the intervention group (n = 200) or the control group (n = 200). Patients in the intervention group received 1.5 g of NBS powder daily for 2 weeks in addition to standard antiviral treatment, while the control group received a placebo alongside standard antiviral therapy. Serum samples were collected from all patients in both groups, and various clinical and laboratory parameters, including ESR, CRP, D-Dimer, CPK, WBC count, lymphocyte count, and lymphocyte percentage, were measured using established methodologies. Following a 14-day intervention period, the intervention group exhibited a significant reduction in mean serum levels of CRP (15.39 vs. 48.49; P < 0.001), ESR (14.28 vs. 34.03; P < 0.001), D-Dimer (485.18 vs. 1009.13; P = 0.001), and CPK (68.93 vs. 131.48; P < 0.001) compared to the control group. Conversely, a significant increase was observed in the mean serum levels of lymphocytes (1537.06 vs. 1152.60; P < 0.001) in the intervention group after 14 days of treatment compared to the control group. The remarkable reduction in inflammatory markers and mortality rates observed with NBS supplementation alongside standard antiviral treatment underscores its crucial role in mitigating inflammation and achieving an important milestone in the fight against COVID-19.

An occurrence of eosinophilic folliculitis and alopecia associated with a sustained complete response to mogamulizumab in Sézary syndrome: a case report

Mogamulizumab is a monoclonal antibody that binds to C-C chemokine receptor 4 (CCR4), initiating antibody-dependent cellular cytotoxicity. CCR4 is highly expressed in the cutaneous T-cell lymphoma subtypes mycosis fungoides and Sézary syndrome (SS), and mogamulizumab has been shown to be effective in patients with these conditions who were refractory to at least one prior systemic treatment. One of the more common adverse events encountered with mogamulizumab is rash, which may mimic disease progression and lead to premature discontinuation. Moreover, there has been some evidence to suggest that mogamulizumab-associated rash (MAR) is associated with improved outcomes in some patients, particularly those with SS. This report presents the case of a 72-year-old woman with SS, which manifested with macular and papular lesions and abnormal blood cytometry, who was treated with mogamulizumab after failure of bexarotene and photopheresis combination therapy. She achieved a complete response (CR), but experienced lymphopenia associated with histologically proven eosinophilic folliculitis (EF) of the scalp and alopecia. The EF responded well to initial topical corticosteroids, defined by regression of erythema and pustular involvement and reduction in pruritus-like symptoms, but without hair regrowth. Mogamulizumab was withdrawn after 32 cycles, but CR was maintained. To date, EF persists in the form of diffuse erythema without pustules or pruritus. A link between cluster of differentiation 4 lymphopenia and EF has previously been established; therefore, EF should be considered in patients who develop rash and lymphopenia while receiving treatment with mogamulizumab. MAR has been associated with clinical response to mogamulizumab, and this case report adds to the evidence that EF may also be associated with sustained clinical response following treatment cessation. However, regular monitoring is required to prevent a relapse of SS. Prospective studies are needed to confirm whether such an association between EF and CR following mogamulizumab exists.

Lymphopenia associated with survivin and its downstream pathway in COVID-19 serving as a potential route in COVID-19 pathogenesis

PURPOSE

Starting in 2019, coronavirus disease 2019 (COVID-19) caused an epidemic that was growing rapidly and has harmed millions of people globally. It has been demonstrated that survivin regulates lymphocyte survival, a main route involved in COVID-19 pathogenesis. Survivin belongs to the inhibitor of apoptosis protein (IAP) family, and its primary functions comprise regulating mitosis and inhibiting apoptosis. Since lower survivin expression has been shown to increase the sensitivity of lymphocytes to apoptotic induction, we looked into the function of survivin and its corresponding pathways in COVID-19 pathogenesis.

MATERIALS AND METHODS

The expression of survivin, X-linked inhibitor of apoptosis protein (XIAP), caspases 3, 7, 9, and poly (ADP-ribose) polymerase (PARP) was evaluated at both mRNA and protein levels in peripheral blood mononuclear cells (PBMCs) derived from healthy donors and patients with severe and moderate COVID-19 by qRT-PCR and Western blotting, respectively. Then, we enforced apoptosis to COVID-19 patient-derived lymphocytes, and the percent was assessed by flow cytometry.

RESULTS

Survivin and XIAP were less expressed in PBMCs derived from COVID-19 patients as apoptosis inhibitors than PARP, cleaved-PARP, caspase 9, and cleaved caspases 3 and 7, according to the results of real-time PCR and Western blot analysis. Additionally, according to the flow cytometry results, the down-regulation of survivin served as a potential factor in the lymphocyte depletion observed in patients with COVID-19.

CONCLUSION

The role of survivin and its related pathway was first discovered in the development of COVID-19 and may serve as a potential prognostic and therapeutic target.

Results of phase 2 randomized multi-center study to evaluate the safety and efficacy of infusion of memory T cells as adoptive therapy in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pneumonia and/or lymphopenia (RELEASE NCT04578210)

BACKGROUND AIMS

There are currently no effective anti-viral treatments for coronavirus disease 2019 (COVID-19)-hospitalized patients with hypoxemia. Lymphopenia is a biomarker of disease severity usually present in patients who are hospitalized. Approaches to increasing lymphocytes exerting an anti-viral effect must be considered to treat these patients. Following our phase 1 study, we performed a phase 2 randomized multicenter clinical trial in which we evaluated the efficacy of the infusion of allogeneic off-the-shelf CD45RA- memory T cells containing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific T cells from convalescent donors plus the standard of care (SoC) versus just the SoC treatment.

METHODS

Eighty-four patients were enrolled in three Spanish centers. The patients were randomized into the infusion of 1 × 106/kg CD45RA- memory T cells or the SoC. We selected four unvaccinated donors based on the expression of interferon gamma SARS-CoV-2-specific response within the CD45RA- memory T cells and the most frequent human leukocyte antigen typing in the Spanish population.

RESULTS

We analyzed data from 81 patients. The primary outcome for recovery, defined as the proportion of participants in each group with normalization of fever, oxygen saturation sustained for at least 24 hours and lymphopenia recovery through day 14 or at discharge, was met for the experimental arm. We also observed faster lymphocyte recovery in the experimental group. We did not observe any treatment-related adverse events.

CONCLUSIONS

Adoptive cell therapy with off-the-shelf CD45RA- memory T cells containing SAR-CoV-2-specific T cells is safe, effective and accelerates lymphocyte recovery of patients with COVID-19 pneumonia and/or lymphopenia.

TRIAL REGISTRATION

NCT04578210.

Risk of extended viral shedding of Omicron BA.2 in Shanghai: Implications for vaccination strategy optimization

Background

In late March 2022, an outbreak of coronavirus disease 2019 (COVID-19) caused by the Omicron BA.2 strain occurred in Shanghai, China. This retrospective study aimed to investigate the clinical characteristics, laboratory parameters, and vaccine protectiveness related to this disease in China.

Methods

We conducted a single-center retrospective study on 735 patients with COVID-19 hospitalized from March 17 to May 14, 2022. Clinical characteristics were analyzed based on vaccination status and viral shedding time (VST). The least absolute shrinkage and selection operator (LASSO) regression and 5-fold cross-validation were applied to screen factors linked to the rate of the VST. Generalized linear models were further applied to estimate the odds ratios for factors influencing the VST.

Results

The median VST of unvaccinated patients was 13 (11-16) days, which was longer than that of patients vaccinated with one or two doses (11 [9-13] days) and with completed booster doses (11 [8-12] days). A LASSO regression model and 5-fold cross-validation showed that age of ≥60 years (β = 0.01), pneumonia (β = 0.53), and higher number of comorbidities (β = 0.69) were positively associated with the VST, whereas the platelet count (β = -8.0×10-5) was inversely associated with the VST. Subgroup analysis revealed that the number of vaccinations was significantly associated with a decreased VST among patients with renal dysfunction (odds ratio [OR], 0.65; 95% confidence interval [CI], 0.44-0.97; P = 0.034) and patients with two or more comorbidities (OR, 0.09; 95% CI, 0.03-0.28; P < 0.001). The lymphocyte count was significantly associated with a decreased VST among patients aged <60 years (OR, 0.51; 95% CI, 0.30-0.85; P = 0.011), patients with normal renal function (OR, 0.41; 95% CI, 0.21-0.80; P = 0.009), and patients with fewer than two comorbidities (OR, 0.49; 95% CI, 0.30-0.80; P = 0.005).

Conclusion

Our preliminary results suggest that the complete and booster vaccination contributes to the viral clearance of Omicron BA.2 variants, while the protectiveness of vaccination is most imperative in patients with impaired renal function and more comorbidities.

The immunomodulating activity of trimodulin (polyvalent IgM, IgA, IgG solution): a post hoc analysis of the phase II CIGMA trial

BACKGROUND

The phase II CIGMA trial performed in 160 patients with severe community-acquired pneumonia (sCAP) found treatment with trimodulin (human polyvalent immunoglobulin [Ig]: ~ 23% IgM, ~ 21% IgA, ~ 56% IgG) was associated with a lower mortality in those patients with elevated baseline serum levels of C-reactive protein (CRP) and/or subnormal IgM.

METHODS

In this post hoc analysis, the pharmacodynamic effects of trimodulin treatment (182.6 mg/kg/day for 5 days) were investigated on Ig replenishment, cellular markers of inflammation (absolute neutrophil [ANC] and lymphocyte [ALC] count, neutrophil-to-lymphocyte ratio [NLR]), and soluble markers of inflammation (procalcitonin [PCT] and CRP). The impact of these pharmacodynamic effects on mortality was also evaluated.

RESULTS

Compared with healthy subjects, baseline serum levels of IgM, IgG, and ALC were significantly lower, and ANC, NLR, PCT and CRP significantly higher in sCAP patients (p < 0.0001). Low Ig concentrations increased with trimodulin. Normalization of ANC (analysis of variance [ANOVA] p = 0.016) and PCT (ANOVA p = 0.027) was more rapid with trimodulin compared with placebo. These and other effects were more evident in patients with low baseline IgM levels. Normalization of PCT and CRP levels was both steadier and faster with trimodulin treatment. In patients with low baseline ALC, trimodulin was associated with a lower 28-day all-cause mortality rate (14.5% vs 32.1% in placebo, p = 0.043) and more ventilator-free days ([VFD]; median VFD: 3.5 vs 11 in placebo, p = 0.043). These numerical differences were greater if baseline IgM was also low (low ALC, low IgM: 8.1% mortality vs 34.1% placebo, p = 0.006; 3 VFD vs 15 VFD, p = 0.009, respectively). Results were consistent in patients with high baseline CRP (low ALC, high CRP: 10.9% mortality vs 34.1% placebo, p = 0.011).

CONCLUSIONS

This post hoc pharmacodynamic analysis of a blinded phase II trial suggests that trimodulin compensates for, and more rapidly modifies, the dysregulated inflammatory response seen in sCAP patients. Trimodulin was associated with significantly lower mortality and more VFD in subgroups with high CRP and low ALC. This effect was particularly marked in patients who also had low baseline IgM values. These findings require confirmation in prospective trials.

Comparative analysis of clinical and immunological profiles across Omicron BA.5.2 subvariants using next-generation sequencing in a Chinese cohort

Objective

The Omicron BA.5.2 variant of SARS-CoV-2 has undergone several evolutionary adaptations, leading to multiple subvariants. Rapid and accurate characterization of these subvariants is essential for effective treatment, particularly in critically ill patients. This study leverages Next-Generation Sequencing (NGS) to elucidate the clinical and immunological features across different Omicron BA.5.2 subvariants.

Methods

We enrolled 28 patients infected with the Omicron variant, hospitalized in Zhangjiajie People's Hospital, Hunan, China, between January 20, 2023, and March 31, 2023. Throat swabs were collected upon admission for NGS-based identification of Omicron subvariants. Clinical data, including qSOFA scores and key laboratory tests, were collated. A detailed analysis of lymphocyte subsets was conducted to ascertain the extent of immune cell damage and disease severity.

Results

Patients were infected with various Omicron subvariants, including BA.5.2.48, BA.5.2.49, BA.5.2.6, BF.7.14, DY.1, DY.2, DY.3, and DY.4. Despite having 43 identical mutation sites, each subvariant exhibited unique marker mutations. Critically ill patients demonstrated significant depletion in total lymphocyte count, T cells, CD4, CD8, B cells, and NK cells (P < 0.05). However, there were no significant differences in clinical and immunological markers across the subvariants.

Conclusion

This study reveals that critically ill patients infected with different Omicron BA.5.2 subvariants experience similar levels of cellular immune dysfunction and inflammatory response. Four mutations - ORF1a:K3353R, ORF1a:L3667F, ORF1b:S997P, S:T883I showed correlation with immunological responses although this conclusion suffers from the small sample size. Our findings underscore the utility of NGS in the comprehensive assessment of infectious diseases, contributing to more effective clinical decision-making.

HCG18, LEF1AS1 and lncCEACAM21 as biomarkers of disease severity in the peripheral blood mononuclear cells of COVID-19 patients

BACKGROUND

Even after 3 years from SARS-CoV-2 identification, COVID-19 is still a persistent and dangerous global infectious disease. Significant improvements in our understanding of the disease pathophysiology have now been achieved. Nonetheless, reliable and accurate biomarkers for the early stratification of COVID-19 severity are still lacking. Long noncoding RNAs (LncRNAs) are ncRNAs longer than 200 nucleotides, regulating the transcription and translation of protein-coding genes and they can be found in the peripheral blood, thus holding a promising biomarker potential. Specifically, peripheral blood mononuclear cells (PBMCs) have emerged as a source of indirect biomarkers mirroring the conditions of tissues: they include monocytes, B and T lymphocytes, and natural killer T cells (NKT), being highly informative for immune-related events.

METHODS

We profiled by RNA-Sequencing a panel of 2906 lncRNAs to investigate their modulation in PBMCs of a pilot group of COVID-19 patients, followed by qPCR validation in 111 hospitalized COVID-19 patients.

RESULTS

The levels of four lncRNAs were found to be decreased in association with COVID-19 mortality and disease severity: HLA Complex Group 18-242 and -244 (HCG18-242 and HCG18-244), Lymphoid Enhancer Binding Factor 1-antisense 1 (LEF1-AS1) and lncCEACAM21 (i.e. ENST00000601116.5, a lncRNA in the CEACAM21 locus). Interestingly, these deregulations were confirmed in an independent patient group of hospitalized patients and by the re-analysis of publicly available single-cell transcriptome datasets. The identified lncRNAs were expressed in all of the PBMC cell types and inversely correlated with the neutrophil/lymphocyte ratio (NLR), an inflammatory marker. In vitro, the expression of LEF1-AS1 and lncCEACAM21 was decreased upon THP-1 monocytes exposure to a relevant stimulus, hypoxia.

CONCLUSION

The identified COVID-19-lncRNAs are proposed as potential innovative biomarkers of COVID-19 severity and mortality.

Receptor-dependent effects of sphingosine-1-phosphate (S1P) in COVID-19: the black side of the moon

Severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) infection leads to hyper-inflammation and amplified immune response in severe cases that may progress to cytokine storm and multi-organ injuries like acute respiratory distress syndrome and acute lung injury. In addition to pro-inflammatory cytokines, different mediators are involved in SARS-CoV-2 pathogenesis and infection, such as sphingosine-1-phosphate (S1P). S1P is a bioactive lipid found at a high level in plasma, and it is synthesized from sphingomyelin by the action of sphingosine kinase. It is involved in inflammation, immunity, angiogenesis, vascular permeability, and lymphocyte trafficking through G-protein coupled S1P receptors. Reduction of the circulating S1P level correlates with COVID-19 severity. S1P binding to sphingosine-1-phosphate receptor 1 (S1PR1) elicits endothelial protection and anti-inflammatory effects during SARS-CoV-2 infection, by limiting excessive INF-α response and hindering mitogen-activated protein kinase and nuclear factor kappa B action. However, binding to S1PR2 opposes the effect of S1PR1 with vascular inflammation, endothelial permeability, and dysfunction as the concomitant outcome. This binding also promotes nod-like receptor pyrin 3 (NLRP3) inflammasome activation, causing liver inflammation and fibrogenesis. Thus, higher expression of macrophage S1PR2 contributes to the activation of the NLRP3 inflammasome and the release of pro-inflammatory cytokines. In conclusion, S1PR1 agonists and S1PR2 antagonists might effectively manage COVID-19 and its severe effects. Further studies are recommended to elucidate the potential conflict in the effects of S1P in COVID-19.

Increased serum interleukin-6 and lactate dehydrogenase levels among nonsurvival severe COVID-19 patients when compared to survival ones

BACKGROUND

Accurate and rapid laboratory diagnosis of COVID-19 infection and its deterioration is one of the milestones of pandemic control. Therefore, this study aimed to compare the diagnostic and prognostic accuracy of the mainly used laboratory biomarkers (WBCS, neutrophil and lymphocyte percentages, CRP, ferritin, IL-6, D-dimer, procalcitonin, and LDH) in the sera of severe COVID-19 Egyptian patients to assess the most appropriate biomarker used in severe COVID-19 patients.

METHODS

A total of 180 unvaccinated severe COVID-19 patients were enrolled in our study. Demographic data, hospitalization time, medical history, oxygen saturation, respiratory rate, oxygen supply, laboratory findings, and thorax tomography of the patients were obtained retrospectively from the hospital's electronic information system.

RESULTS

Our results revealed that the levels of neutrophil percentage, CRP, IL-6, PCT, and LDH were significantly increased while lymphocyte percentage was significantly decreased among nonsurvival severe COVID-19 patients when compared with survival ones. By using ROC curve analysis, IL-6, and LDH are the most sensitive and specific markers for the prediction of bad prognosis and mortality among severe COVID-19 patients with 100% and 93% sensitivity and 93.7% specificity; respectively. IL-6 and LDH showed significant correlations with the other parameters, which suggested their association with the severity of COVID-19.

CONCLUSION

By using survival severe COVID-19 patients as a control group, our results showed that blood neutrophil percentage, serum CRP, IL-6, PCT, and LDH were significantly increased in non-survivors as compared to survivors. As biomarkers, our results revealed that IL-6 and LDH are good predictors of mortality among severe COVID-19 patients.

Characteristics and Outcomes of COVID-19 Cancer Patients Admitted to a Portuguese Intensive Care Unit: A Case-Control Study

Cancer patients appear to be a vulnerable group in the COVID-19 pandemic. This study aims to compare clinical characteristics and outcomes of cancer and non-cancer patients with COVID-19 admitted to the ICU. All COVID-19 cancer patients (cases) admitted to a Portuguese ICU between March 2020 and January 2021 were included and matched on age, sex and comorbidities with COVID-19 non-cancer patients (controls); 29 cases and 29 controls were enrolled. Initial symptoms were similar between the two groups. Anemia was significantly superior among cases (76% vs. 45%; p = 0.031). Invasive mechanical ventilation (IMV) need at ICU admission was significantly higher among cases (48% vs. 7%; odds ratio (OR) = 12.600, 95% CI: 2.517-63.063, p = 0.002), but there were no differences for global need for IMV during all-length of ICU stay and mortality rates. In a multivariate model of logistic regression, the risk of IMV need at ICU admission among cases remained statistically significant (adjusted OR = 14.036, 95% CI: 1.337-153.111, p = 0.028). Therefore, compared to critical non-cancer patients, critical cancer patients with COVID-19 had an increased risk for IMV need at the moment of ICU admission, however, not for IMV need during all-length of ICU stay or death.

Alterations in the CD56- and CD56+ T Cell Subsets during COVID-19

The effectiveness of the antiviral immune response largely depends on the activation of cytotoxic T cells. The heterogeneous group of functionally active T cells expressing the CD56 molecule (NKT-like cells), that combines the properties of T lymphocytes and NK cells, is poorly studied in COVID-19. This work aimed to analyze the activation and differentiation of both circulating NKT-like cells and CD56^- T cells during COVID-19 among intensive care unit (ICU) patients, moderate severity (MS) patients, and convalescents. A decreased proportion of CD56⁺ T cells was found in ICU patients with fatal outcome. Severe COVID-19 was accompanied by a decrease in the proportion of CD8⁺ T cells, mainly due to the CD56^- cell death, and a redistribution of the NKT-like cell subset composition with a predominance of more differentiated cytotoxic CD8⁺ T cells. The differentiation process was accompanied by an increase in the proportions of KIR2DL2/3⁺ and NKp30⁺ cells in the CD56⁺ T cell subset of COVID-19 patients and convalescents. Decreased percentages of NKG2D⁺ and NKG2A⁺ cells and increased PD-1 and HLA-DR expression levels were found in both CD56^- and CD56⁺ T cells, and can be considered as indicators of COVID-19 progression. In the CD56^- T cell fraction, increased CD16 levels were observed in MS patients and in ICU patients with lethal outcome, suggesting a negative role for CD56^-CD16⁺ T cells in COVID-19. Overall, our findings suggest an antiviral role of CD56⁺ T cells in COVID-19.

Fungal infection profile in critically ill COVID-19 patients: a prospective study at a large teaching hospital in a middle-income country

BACKGROUND

Critically ill COVID-19 patients are highly susceptible to opportunistic fungal infection due to many factors, including virus-induced immune dysregulation, host-related comorbidities, overuse and misuse of antibiotics or corticosteroids, immune modulator drugs, and the emergencies caused by the pandemic. This study aimed to assess the incidence, identify the potential risk factors, and examine the impact of fungal coinfection on the outcomes of COVID-19 patients admitted to the intensive care unit (ICU).

METHODS

A prospective cohort study including 253 critically ill COVID-19 patients aged 18 years or older admitted to the isolation ICU of Zagazig University Hospitals over a 4-month period from May 2021 to August 2021 was conducted. The detection of a fungal infection was carried out.

RESULTS

Eighty-three (83) patients (32.8%) were diagnosed with a fungal coinfection. Candida was the most frequently isolated fungus in 61 (24.1%) of 253 critically ill COVID-19 patients, followed by molds, which included Aspergillus 11 (4.3%) and mucormycosis in five patients (1.97%), and six patients (2.4%) diagnosed with other rare fungi. Poor diabetic control, prolonged or high-dose steroids, and multiple comorbidities were all possible risk factors for fungal coinfection [OR (95% CI) = 10.21 (3.43-30.39), 14.1 (5.67-35.10), 14.57 (5.83-33.78), and 4.57 (1.83-14.88), respectively].

CONCLUSION

Fungal coinfection is a common complication of critically ill COVID-19 patients admitted to the ICU. Candidiasis, aspergillosis, and mucormycosis are the most common COVID-19-associated fungal infections and have a great impact on mortality rates.

COVID-19: Attacks Immune Cells and Interferences With Antigen Presentation Through MHC-Like Decoy System

The high mortality of coronavirus disease 2019 is related to poor antigen presentation and lymphopenia. Cytomegalovirus and the herpes family encode a series of major histocompatibility complex (MHC)-like molecules required for targeted immune responses to achieve immune escape. In this present study, domain search results showed that many proteins of the severe acute respiratory syndrome coronavirus 2 virus had MHC-like domains, which were similar to decoys for the human immune system. MHC-like structures could bind to MHC receptors of immune cells (such as CD4 + T-cell, CD8 + T-cell, and natural killer-cell), interfering with antigen presentation. Then the oxygen free radicals generated by E protein destroyed immune cells after MHC-like of S protein could bind to them. Mutations in the MHC-like region of the viral proteins such as S promoted weaker immune resistance and more robust transmission. S 127-194 were the primary reason for the robust transmission of delta variants. The S 144-162 regulated the formation of S trimer. The mutations of RdRP: G671S and N: D63G of delta variant caused high viral load. S 62-80 of alpha, beta, lambda variants were the important factor for fast-spreading. S 616-676 and 1014-1114 were causes of high mortality for gamma variants infections. These sites were in the MHC-like structure regions.

The immune paradox of SARS-CoV-2: Lymphocytopenia and autoimmunity evoking features in COVID-19 and possible treatment modalities

SARS-CoV-2 causes multiorgan damage to vital organs and tissue that are known to be due to a combination of tissue tropisms and cytokine-mediated damage that it can incite in COVID-19. The effects of SARS-Co-2 on the lymphocytes and therefore on the immune response have attracted attention recently in COVID-19 to understand its effects in causing a chronic state of ongoing infection with Long-COVID. The associated lymphopaenia and autoimmune disease state, which is an apparent paradox, needs to be researched to dissect possible mechanisms underlying this state. This paper attempts to unravel the aforesaid immune paradox effects of SARS-CoV-2 on the lymphocytes and discusses appropriate treatment modalities with antiviral drugs and nutraceuticals which could prove virucidal in SARS-CoV-2 seeding monocytes and lymphocytes in patients with COVID-19 and Long-COVID. Importantly it proposes a new in vitro treatment modality of immune regulating cells that can help patients fight the lymphopaenia associated with COVID-19 and Long-COVID.

Donor selection for adoptive cell therapy with CD45RA- memory T cells for patients with coronavirus disease 2019, and dexamethasone and interleukin-15 effects on the phenotype, proliferation and interferon gamma release

BACKGROUND AIMS

We have previously demonstrated the safety and feasibility of adoptive cell therapy with CD45RA- memory T cells containing severe acute respiratory syndrome coronavirus 2-specific T cells for patients with coronavirus disease 2019 from an unvaccinated donor who was chosen based on human leukocyte antigen compatibility and cellular response. In this study, we examined the durability of cellular and humoral immunity within CD45RA- memory T cells and the effect of dexamethasone, the current standard of care treatment, and interleukin-15, a cytokine critically involved in T-cell maintenance and survival.

METHODS

We performed a longitudinal analysis from previously severe acute respiratory syndrome coronavirus 2-infected and infection-naïve individuals covering 21 months from infection and 10 months after full vaccination with the BNT162b2 Pfizer/BioNTech vaccine.

RESULTS

We observed that cellular responses are maintained over time. Humoral responses increased after vaccination but were gradually lost. In addition, dexamethasone did not alter cell functionality or proliferation of CD45RA- T cells, and interleukin-15 increased the memory T-cell activation state, regulatory T cell expression, and interferon gamma release.

CONCLUSIONS

Our results suggest that the best donors for adoptive cell therapy would be recovered individuals and 2 months after vaccination, although further studies with larger cohorts would be needed to confirm this finding. Dexamethasone did not affect the characteristics of the memory T cells at a concentration used in the clinical practice and IL-15 showed a positive effect on SARS-CoV-2-specific CD45RA- T cells.

Role of T cells in severe COVID-19 disease, protection, and long term immunity

Infection with SARS-CoV-2 causes wide range of disease severities from asymptomatic to life-threatening disease. Understanding the contribution of immunological traits in immunity against SARS-CoV-2 and in protection against severe COVID-19 could result in effective measures to prevent development of severe disease. While the role of cytokines and antibodies has been thoroughly studied, this is not the case for T cells. In this review, the association between T cells and COVID-19 disease severity and protection upon reexposure is discussed. While infiltration of overactivated cytotoxic T cells might be harmful in the infected tissue, fast responding T cells are important in the protection against severe COVID-19. This protection could even be viable in the long term as long-living memory T cells seem to be stabilized and mutations do not appear to have a large impact on T cell responses. Thus, after vaccination and infections, memory T cells should be able to help prevent onset of severe disease for most cases. Considering this, it would be useful to add N or M proteins in vaccinations, alongside the S protein which is currently used, as this results in a broader T cell response.

Severity of Illness Scores and Biomarkers for Prognosis of Patients with Coronavirus Disease 2019

The spectrum of disease severity and the insidiousness of clinical presentation make it difficult to recognize patients with coronavirus disease 2019 (COVID-19) at higher risk of worse outcomes or death when they are seen in the early phases of the disease. There are now well-established risk factors for worse outcomes in patients with COVID-19. These should be factored in when assessing the prognosis of these patients. However, a more precise prognostic assessment in an individual patient may warrant the use of predictive tools. In this manuscript, we conduct a literature review on the severity of illness scores and biomarkers for the prognosis of patients with COVID-19. Several COVID-19-specific scores have been developed since the onset of the pandemic. Some of them are promising and can be integrated into the assessment of these patients. We also found that the well-known pneumonia severity index (PSI) and CURB-65 (confusion, uremia, respiratory rate, BP, age ≥ 65 years) are good predictors of mortality in hospitalized patients with COVID-19. While neither the PSI nor the CURB-65 should be used for the triage of outpatient versus inpatient treatment, they can be integrated by a clinician into the assessment of disease severity and can be used in epidemiological studies to determine the severity of illness in patient populations. Biomarkers also provide valuable prognostic information and, importantly, may depict the main physiological derangements in severe disease. We, however, do not advocate the isolated use of severity of illness scores or biomarkers for decision-making in an individual patient. Instead, we suggest the use of these tools on a case-by-case basis with the goal of enhancing clinician judgment.

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.

Development of a prediction score (ThyroCOVID) for identifying abnormal thyroid function in COVID-19 patients

PURPOSE

Thyroid dysfunction in COVID-19 carries clinical and prognostic implications. In this study, we developed a prediction score (ThyroCOVID) for abnormal thyroid function (TFT) on admission amongst COVID-19 patients.

METHODS

Consecutive COVID-19 patients admitted to Queen Mary Hospital were prospectively recruited during July 2020-May 2021. Thyroid-stimulating hormone (TSH), free thyroxine (fT4) and free triiodothyronine (fT3) were measured on admission. Multivariable logistic regression analysis was performed to identify independent determinants of abnormal TFTs. ThyroCOVID was developed based on a clinical model with the lowest Akaike information criteria.

RESULTS

Five hundred and forty six COVID-19 patients were recruited (median age 50 years, 45.4% men, 72.9% mild disease on admission). 84 patients (15.4%) had abnormal TFTs on admission. Patients with abnormal TFTs were more likely to be older, have more comorbidities, symptomatic, have worse COVID-19 severity, higher SARS-CoV-2 viral loads and more adverse profile of acute-phase reactants, haematological and biochemical parameters. ThyroCOVID consisted of five parameters: symptoms (malaise), comorbidities (ischaemic heart disease/congestive heart failure) and laboratory parameters (lymphocyte count, C-reactive protein, and SARS-CoV-2 cycle threshold values). It was able to identify abnormal TFT on admission with an AUROC of 0.73 (95% CI 0.67-0.79). The optimal cut-off of 0.15 had a sensitivity of 75.0%, specificity of 65.2%, negative predictive value of 93.5% and positive predictive value of 28.1% in identifying abnormal TFTs on admission amongst COVID-19 patients.

CONCLUSION

ThyroCOVID, a prediction score to identify COVID-19 patients at risk of having abnormal TFT on admission, was developed based on a cohort of predominantly non-severe COVID-19 patients.

Generation of Cytotoxic T Cells and Dysfunctional CD8 T Cells in Severe COVID-19 Patients

COVID-19, the infectious disease caused by SARS-CoV-2, has spread on a pandemic scale. The viral infection can evolve asymptomatically or can generate severe symptoms, influenced by the presence of comorbidities. Lymphopenia based on the severity of symptoms in patients affected with COVID-19 is frequent. However, the profiles of CD4+ and CD8+ T cells regarding cytotoxicity and antiviral factor expression have not yet been completely elucidated in acute SARS-CoV-2 infections. The purpose of this study was to evaluate the phenotypic and functional profile of T lymphocytes in patients with moderate and severe/critical COVID-19. During the pandemic period, we analyzed a cohort of 62 confirmed patients with SARS-CoV-2 (22 moderate cases and 40 severe/critical cases). Notwithstanding lymphopenia, we observed an increase in the expression of CD28, a co-stimulator molecule, and activation markers (CD38 and HLA-DR) in T lymphocytes as well as an increase in the frequency of CD4+ T cells, CD8+ T cells, and NK cells that express the immunological checkpoint protein PD-1 in patients with a severe/critical condition compared to healthy controls. Regarding the cytotoxic profile of peripheral blood mononuclear cells, an increase in the response of CD4+ T cells was already observed at the baseline level and scarcely changed upon PMA and Ionomycin stimulation. Meanwhile, CD8+ T lymphocytes decreased the cytotoxic response, evidencing a profile of exhaustion in patients with severe COVID-19. As observed by t-SNE, there were CD4+ T-cytotoxic and CD8+ T with low granzyme production, evidencing their dysfunction in severe/critical conditions. In addition, purified CD8+ T lymphocytes from patients with severe COVID-19 showed increased constitutive expression of differentially expressed genes associated with the caspase pathway, inflammasome, and antiviral factors, and, curiously, had reduced expression of TNF-α. The cytotoxic profile of CD4+ T cells may compensate for the dysfunction/exhaustion of TCD8+ in acute SARS-CoV-2 infection. These findings may provide an understanding of the interplay of cytotoxicity between CD4+ T cells and CD8+ T cells in the severity of acute COVID-19 infection.

Inflammatory and blood gas markers of COVID-19 delirium compared to non-COVID-19 delirium: a cross-sectional study

OBJECTIVES

We aimed to find the association of inflammation and respiratory failure with delirium in COVID-19 patients. We compare the inflammatory and arterial blood gas markers between patients with COVID-19 delirium and delirium in other medical disorders.

METHODS

This cross-sectional study used the CHART-DEL, a validated research tool, to screen patients for delirium retrospectively from clinical notes. Inflammatory markers C-reactive protein (CRP) and white cell count (WBC), and the partial pressures of oxygen (PO₂) and carbon dioxide (PCO₂) were compared between patients with COVID-19 delirium and delirium in other medical disorders.

RESULTS

In bivariate analysis, CRP (mg/L) was significantly higher in the COVID-19 group, (81.7 ± 80.0 vs. 58.8 ± 87.7, p = 0.04), and WBC (10⁹/L) was significantly lower (7.44 ± 3.42 vs. 9.71 ± 5.45, p = 0.04). The geometric mean of CRP in the COVID-19 group was 140% higher in multiple linear regression (95% CI = 7-439%, p = 0.03) with age and sex as covariates. There were no significant differences in pO₂ or pCO₂ across groups.

CONCLUSION

The association between higher CRP and COVID-19 in patients with delirium may suggest an inflammatory basis for delirium in COVID-19. Our findings may assist clinicians in establishing whether delirium is due to COVID-19, which may improve management and outcomes of infected patients.

IL-6 drives T cell death to participate in lymphopenia in COVID-19

Lymphopenia is a common observation in patients with COVID-19. To explore the cause of T cell lymphopenia in the disease, laboratory results of 64 hospitalized COVID-19 patients were retrospectively analyzed and six patients were randomly selected to trace their changes of T lymphocytes and plasma concentration of IL-6 for the course of disease. Results confirmed that the T-cell lymphopenia, especially CD4⁺ T cell reduction in COVID-19 patients, was a reliable indicator of severity and hospitalization in infected patients. And CD4⁺ T cell count below 200 cells/μL predicts critical illness in COVID-19 patients. In vitro assay supported that exposure to key contributors (IL-1β, IL-6, TNF-α and IFN-γ) of COVID-19 cytokine storm caused substantial death of activated T cells. Among these contributors, IL-6 level was found to probably reversely correlate with T cell counts in patients. And IL-6 alone was potent to induce T cell reduction by gasderminE-mediated pyroptosis, inferring IL-6 took a part in affecting the function and status of T cells in COVID-19 patients. Intervention of IL-6 mediated T cell pryprotosis may effectively delay disease progression, maintain normal immune status at an early stage of infection.

Immune modulation as a consequence of SARS-CoV-2 infection

Erroneous immune responses in COVID-19 could have detrimental effects, which makes investigation of immune network underlying COVID-19 pathogenesis a requisite. This study aimed to investigate COVID-19 related alterations within the frame of innate and adaptive immunity. Thirty-four patients clinically diagnosed with mild, moderate and severe COVID-19 disease were enrolled in this study. Decreased ILC1 and increased ILC2 subsets were detected in mild and moderate patients compared to healthy controls. NK cell subsets and cytotoxic capacity of NK cells were decreased in severe patients. Moreover, CD3+ T cells were reduced in severe patients and a negative correlation was found between CD3+ T cells and D-dimer levels. Likewise, moderate and severe patients showed diminished CD3+CD8+ T cells. Unlike T and NK cells, plasmablast and plasma cells were elevated in patients and IgG and IgA levels were particularly increased in severe patients. Severe patients also showed elevated serum levels of pro-inflammatory cytokines such as TNF-α, IL-6 and IL-8, reduced intracellular IFN-γ and increased intracellular IL-10 levels. Our findings emphasize that SARS-CoV-2 infection significantly alters immune responses and innate and acquired immunity are differentially modulated in line with the clinical severity of the disease. Elevation of IL-10 levels in NK cells and reduction of CD3+ and CD8+ T cells in severe patients might be considered as a protective response against the harmful effect of cytokine storm seen in COVID-19.

Effects of lymphocyte and neutrophil counts and their time courses on mortality in patients with postoperative pneumonia

The prognostic significance of absolute lymphocyte count (ALC) and absolute neutrophil count (ANC) remains unclear in patients with postoperative pneumonia (POP). The study objectives were to investigate the prognostic effects of ALC and ANC in POP patients, and to evaluate the time courses of ALC and ANC during hospitalization. This post-hoc analysis of a single-center prospective observational study evaluated consecutive POP patients, and comparatively analyzed community-acquired pneumonia (CAP) patients to highlight features of POP. In total, 228 POP patients and 1027 CAP patients were assessed. Severe lymphopenia (ALC < 500 cells/μL) at diagnosis was associated with worse 90-day survival in both types of pneumonia. In POP patients, neutrophilia (ANC > 7500 cells/μL) was associated with better survival, whereas CAP patients with neutrophilia tended to have a lower survival rate. Prolonged lymphopenia and delayed increase in neutrophils were characteristic time-course changes of non-survivors in POP. The time courses of ALC and ANC between survivors and non-survivors in POP trended differently from those in CAP. Our study showed that ALC and ANC at pneumonia diagnosis can serve as prognostic factors in POP patients. Differences in time-course changes of ALC and ANC between survivors and non-survivors may provide important information for future immunological research in pneumonia.

Oropharyngeal Candidiasis among Egyptian COVID-19 Patients: Clinical Characteristics, Species Identification, and Antifungal Susceptibility, with Disease Severity and Fungal Coinfection Prediction Models

The study aimed to investigate the causative species, antifungal susceptibility, and factors associated with oropharyngeal candidiasis (OPC) among Egyptian COVID-19 patients. This is an observational, case-controlled, single-center study that included three groups: COVID-19 patients (30), COVID-19 patients with OPC (39), and healthy individuals (31). Patients’ demographic data (age, sex), laboratory tests, comorbidities, treatment, and outcomes were included. Candida species were isolated from COVID-OPC patient’s oropharyngeal swabs by convenient microbiological methods. Isolated strains were tested for antimicrobial susceptibility, biofilm production, aspartyl protease, and phospholipase activities. The most common respiratory symptoms reported were dyspnea (36/39; 92.4%) and cough (33/39; 84.7%). Candida albicans was the most common isolated species, accounting for 74.36% (29/39), followed by Candida tropicalis and Candida glabrata (15.38% and 10.26%, respectively). Amphotericin was effective against all isolates, while fluconazole was effective against 61.5%. A total of 53.8% of the isolates were biofilm producers. The phospholipase activity of C. albicans was detected among 58.6% (17/29) of the isolates. Significant variables from this study were used to create two equations from a regression model that can predict the severity of disease course and liability to fungal infection, with a stativity of 87% and 91%, respectively. According to our findings, COVID-19 patients with moderate to severe infection under prolonged use of broad-spectrum antibiotics and corticosteroids should be considered a high-risk group for developing OPC, and prophylactic measures are recommended to be included in the treatment protocols. In addition, due to the increased rate of fluconazole resistance, other new antifungals should be considered.

Predictors of Noninvasive Respiratory Support Failure in COVID-19 Patients: A Prospective Observational Study

Background and Objective: Respiratory assistance tactic that is best for COVID-19-associated acute hypoxemic respiratory failure (AHRF) individuals has yet to be determined. Patients with AHRF may benefit from the use of a high-flow nasal cannula (HFNC) and non-invasive ventilation (NIV). The goals of this prospective observational research were to estimate predictive factors for HFNC and NIV failure in COVID-19-related AHRF subjects. Materials and Methods: The research enlisted the participation of 124 patients. A stepwise treatment approach was used. HFNC and NIV were used on 124 (100%) and 64 (51.6%) patients, respectively. Thirty (24.2%) of 124 patients were intubated and received invasive mechanical ventilation. Results: 85 (68.5%) patients were managed successfully. Patients who required NIV exhibited a higher prevalence of treatment failure (70.3% vs. 51.6%, p = 0.019) and had higher mortality (59.4% vs. 31.5%, p = 0.001) than patients who received HFNC. Using logistic regression, the respiratory rate oxygenation (ROX) index at 24 h (odds ratio (OR) = 0.74, p = 0.018) and the Charlson Comorbidity Index (CCI) (OR = 1.60, p = 0.003) were found to be predictors of HFNC efficacy. It was the ROX index at 24 h and the CCI optimum cut-off values for HFNC outcome that were 6.1 (area under the curve (AUC) = 0.73) and 2.5 (AUC = 0.68), respectively. Serum ferritin level (OR = 0.23, p = 0.041) and lymphocyte count (OR = 1.03, p = 0.01) were confirmed as predictors of NIV failure. Serum ferritin level at a cut-off value of 456.2 ng/mL (AUC = 0.67) and lymphocyte count lower than 0.70 per mm³, (AUC = 0.70) were associated with NIV failure with 70.5% sensitivity, 68.7% specificity and sensitivity of 84.1%, specificity of 56.2%, respectively. Conclusion: The ROX index at 24 h, CCI, as well as serum ferritin level, and lymphocyte count can be used as markers for HFNC and NIV failure, respectively, in SARS-CoV-2-induced AHRF patients.

Clinical utility of inflammatory biomarkers in COVID-19 in direct comparison to other respiratory infections-A prospective cohort study

Background

Inflammatory biomarkers are associated with severity of coronavirus disease 2019 (COVID-19). However, direct comparisons of their utility in COVID-19 versus other respiratory infections are largely missing.

Objective

We aimed to investigate the prognostic utility of various inflammatory biomarkers in COVID-19 compared to patients with other respiratory infections.

Materials and methods

Patients presenting to the emergency department with symptoms suggestive of COVID-19 were prospectively enrolled. Levels of Interleukin-6 (IL-6), c-reactive protein (CRP), procalcitonin, ferritin, and leukocytes were compared between COVID-19, other viral respiratory infections, and bacterial pneumonia. Primary outcome was the need for hospitalisation, secondary outcome was the composite of intensive care unit (ICU) admission or death at 30 days.

Results

Among 514 patients with confirmed respiratory infections, 191 (37%) were diagnosed with COVID-19, 227 (44%) with another viral respiratory infection (viral controls), and 96 (19%) with bacterial pneumonia (bacterial controls). All inflammatory biomarkers differed significantly between diagnoses and were numerically higher in hospitalized patients, regardless of diagnoses. Discriminative accuracy for hospitalisation was highest for IL-6 and CRP in all three diagnoses (in COVID-19, area under the curve (AUC) for IL-6 0.899 [95%CI 0.850–0.948]; AUC for CRP 0.922 [95%CI 0.879–0.964]). Similarly, IL-6 and CRP ranged among the strongest predictors for ICU admission or death at 30 days in COVID-19 (AUC for IL-6 0.794 [95%CI 0.694–0.894]; AUC for CRP 0.807 [95%CI 0.721–0.893]) and both controls. Predictive values of inflammatory biomarkers were generally higher in COVID-19 than in controls.

Conclusion

In patients with COVID-19 and other respiratory infections, inflammatory biomarkers harbour strong prognostic information, particularly IL-6 and CRP. Their routine use may support early management decisions.

Comparative Clinical Characteristics, Laboratory Findings, and Outcomes of Hypoxemic and Non-Hypoxemic Patients Treated at a Makeshift COVID-19 Unit in Bangladesh: A Retrospective Chart Analysis

Background: Starting on 31 December 2019, from Wuhan City, China, Coronavirus disease 2019 (COVID-19) caused a global pandemic by 11 March 2020. Bangladesh detected its first case on 8 March 2020, only 66 days later the detection of the first case in China. We aimed to describe the epidemiology, clinical features, laboratory characteristics, and outcomes of Bangladeshi COVID-19 patients. Methods: This retrospective chart analysis compared Bangladeshi COVID-19 patients with hypoxemia compared to those without hypoxemia treated in a makeshift COVID-19 unit of icddr,b. Results: By March 2021, 207 remained in-patient. Nineteen patients (9.2%) died, whereas 10 (4.8%) were referred to different facilities for definitive care. Out of 207 in-patients, 88 patients required oxygen therapy. Multivariable logistic regression identified age (1.07 (1.02−1.13)), dyspnea (3.56 (1.06−11.96)), high CRP (1.13 (1.03−1.25)), and lymphopenia (6.18 (1.81−21.10)) as the independent predictors for hypoxemia in patients hospitalized for COVID 19 (for all, p < 0.05). Conclusion: Older age, dyspnea, high CRP, and lymphopenia are simple, but important, clinical and laboratory parameters. These may help clinicians to identify COVID-19 patients early who are at risk of fatal hypoxemia. Close monitoring, and prompt and aggressive treatment of these patients would curb their morbidity and mortality, especially in resource-limited settings.

SARS-CoV-2 and HIV co-infection; clinical features, diagnosis, and treatment strategies: A systematic review and meta-analysis

Background and aim

Coronavirus disease 2019 (COVID-19) in people living with human immunodeficiency virus (HIV) who has a compromised immune system can be associated with more significant risks for severe complications. To date, no comprehensive study has been performed to evaluate HIV in patients with COVID-19. In the present study, we assessed the status of patients co-infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and HIV as a systematic review and meta-analysis.

Methods

A systematic literature search strategy was conducted via reviewing original research articles published in Medline, Web of Science, and Embase databases in 2019 and 2020. Statistical analysis was performed using STATA software, version 14.0 (Stata Corporation, College Station, Texas, USA), to report the prevalence of HIV among patients with COVID-19. Case reports/case series were also evaluated as a systematic review.

Results

Sixty-three studies (53 case reports/case series and ten prevalence studies) were included in our study. A meta-analysis of prevalence studies showed that HIV infection among patients with COVID-19 was reported in 6 countries (Uganda, China, Iran, USA, Italy, and Spain) with an overall frequency of 1.2% [(95% CI) 0.8–1.7] among 14,424 COVID-19 patients. According to the case reports and case series, 111 patients with HIV have been reported among 113 patients with COVID-19 from 19 countries. Most of the cases were in the USA, China, Italy, and Spain.

Conclusion

The small number of SARS-CoV-2-HIV co-infected patients reported in the literature makes it difficult to draw precise conclusions. However, since people with HIV are more likely to develop more severe complications of COVID-19, targeted policies to address this raised risk in the current pandemic should be considered. Our findings highlight the importance of identifying underlying diseases, co-infections, co-morbidities, laboratory findings, and beneficial treatment strategies for HIV patients during the COVID-19 pandemic.

Characteristic Immune Dynamics in COVID-19 Patients with Cardiac Dysfunction

Background: We aimed to explore immune parameters in COVID-19 patients admitted to the intensive care unit (ICU) to identify distinctive features in patients with cardiac injury. Methods: A total of 30 COVID-19 patients >18 years admitted to the ICU were studied on days D1, D3 and D7 after admission. Cardiac function was assessed using speckle-tracking echocardiography (STE). Peripheral blood immunophenotyping, cardiac (pro-BNP; troponin) and inflammatory biomarkers were simultaneously evaluated. Results: Cardiac dysfunction (DYS) was detected by STE in 73% of patients: 40% left ventricle (LV) systolic dysfunction, 60% LV diastolic dysfunction, 37% right ventricle systolic dysfunction. High-sensitivity cardiac troponin (hs-cTn) was detectable in 43.3% of the patients with a median value of 13.00 ng/L. There were no significant differences between DYS and nDYS patients regarding mortality, organ dysfunction, cardiac (including hs-cTn) or inflammatory biomarkers. Patients with DYS showed persistently lower lymphocyte counts (median 896 [661−1837] cells/µL vs. 2141 [924−3306] cells/µL, p = 0.058), activated CD3 (median 85 [66−170] cells/µL vs. 186 [142−259] cells/µL, p = 0.047) and CD4 T cells (median 33 [28−40] cells/µL vs. 63 [48−79] cells/µL, p = 0.005), and higher effector memory T cells (TEM) at baseline (CD4%: 10.9 [6.4−19.2] vs. 5.9 [4.2−12.8], p = 0.025; CD8%: 15.7 [7.9−22.8] vs. 8.1 [7.7−13.7], p = 0.035; CD8 counts: 40 cells/µL [17−61] vs. 10 cells/µL [7−17], p = 0.011) than patients without cardiac dysfunction. Conclusion: Our study suggests an association between the immunological trait and cardiac dysfunction in severe COVID-19 patients.

Are CMV and SARS-CoV-2 Infections Mutual Risk Factors in Kidney Transplant Recipients?

Throughout the years, much progress has been made in the field of renal transplantation; however, along with new developments, new problems have arisen. While transplantation is the optimal choice in patients suffering from end-stage renal disease, it is always connected to certain commonly associated risks, in particular those caused by opportunistic infections. One such risk includes the reactivation of cytomegalovirus (CMV), an issue commonly affecting all kinds of transplant recipients. Similarly, with the rise of the ever-evolving global SARS-CoV-2 pandemic, patients must be constantly monitored for any respiratory symptoms, and observed closely under the care of their attending physician. Treating these patients has become extremely difficult due to limitations caused by COVID-19 protocols (for instance, the reduction of immunosuppression dosages and the avoidance of lymphocyte-depleting induction therapy) and the lack of knowledge surrounding this relatively new and worsening risk factor. In order to give patients optimal care, these arising problems need to be studied and addressed.

Upregulated Proteasome Subunits in COVID-19 Patients: A Link with Hypoxemia, Lymphopenia and Inflammation

Severe COVID-19 disease leads to hypoxemia, inflammation and lymphopenia. Viral infection induces cellular stress and causes the activation of the innate immune response. The ubiquitin-proteasome system (UPS) is highly implicated in viral immune response regulation. The main function of the proteasome is protein degradation in its active form, which recognises and binds to ubiquitylated proteins. Some proteasome subunits have been reported to be upregulated under hypoxic and hyperinflammatory conditions. Here, we conducted a prospective cohort study of COVID-19 patients (n = 44) and age-and sex-matched controls (n = 20). In this study, we suggested that hypoxia could induce the overexpression of certain genes encoding for subunits from the α and β core of the 20S proteasome and from regulatory particles (19S and 11S) in COVID-19 patients. Furthermore, the gene expression of proteasome subunits was associated with lymphocyte count reduction and positively correlated with inflammatory molecular and clinical markers. Given the importance of the proteasome in maintaining cellular homeostasis, including the regulation of the apoptotic and pyroptotic pathways, these results provide a potential link between COVID-19 complications and proteasome gene expression.

Neutrophil-to-Lymphocyte Ratio and Absolute Lymphocyte Count as Early Diagnostic Tools for Corona Virus Disease 2019

Background and objectives

In comparison to real-time polymerase chain reaction (RT-PCR) testing, blood-related parameters including absolute lymphocyte count (ALC) and neutrophil-to-lymphocyte ratio (NLR) carry an indeterminate potential in the assessment of corona virus disease 2019 (COVID-19). Our main objective was to assess their efficacy in timely identification of COVID-19 patients and to determine whether these biomarkers can be employed as an early diagnostic tool in patients presenting with symptoms suggestive of COVID-19.

Methodology

This cross-sectional study was conducted at the Emergency Department of a Tertiary Care Hospital in Rawalpindi, Pakistan from November 2020 to March 2021. Patients suspected to have COVID-19 on a clinical basis (fever, cough or shortness of breath) were selected by using convenience non-probability sampling. RT-PCR was used to diagnose COVID-19 after evaluating NLR and ALC of the sample population. An NLR = 3.5 and ALC < 1 x 10³ cells/mm³ was considered as the cut-off value. Statistical analysis was conducted via SPSS 23.0 (IBM Corp., Armonk, NY). Chi-square and independent t-tests were used to correlate various data variables, while p-value <0.05 was considered significant.

Results

Out of the 172 subjects included in the study, the mean age was 40.6 ± 10.0 years, while 51% of individuals were males. Fever was found to be the most prevalent complaint (94%). Double RT-PCR testing showed that 51.2% of the population was RT-PCR positive, having a mean ALC of 1.4 ± 0.9 x 10³/mm³, significantly lower than RT-PCR negative cases (p < 0.001). In addition, NLR was drastically elevated for RT-PCR-positive individuals (p < 0.001) while it also had a distinctly high specificity of 91.7% among COVID-19 patients. Additionally, NLR did not correlate with any of the baseline patient-related parameters (presenting complaint, age, and gender).

Conclusion

NLR and ALC are potentially efficacious measures for an early diagnosis of COVID-19, and can be possibly utilized for an early diagnosis of COVID-19 suspects.

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

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

The Correlation between Neutrophil-to-Lymphocyte Ratio with C-reactive Protein and D-dimer Level among Indonesian COVID-19 Cases

BACKGROUND: Coronavirus disease-19 (COVID-19) pandemic has resulted high number of mortalities globally. Several inflammatory and coagulation biomarkers have been studied for predicting and differentiating severe COVID-19 such as C-reactive protein (CRP) and D-dimer. However, those markers may not readily available in developing countries. AIM: The aim of the study was to assess the utility of neutrophil-to-lymphocyte ratio (NLR), a widely available and inexpensive laboratory examination, as reliable inflammatory biomarkers for Indonesian COVID-19 patients; by analyzing the correlation of NLR level with CRP and D-dimer plasma level. METHODS: We conducted cross-sectional study in Professor Dr. R.D. Kandou Hospital, Manado involving RT-PCR confirmed and hospitalized COVID-19 patients. Lymphocyte count, NLR, CRP, and D-dimer were examined in severe and non-severe COVID-19 cases at hospital admission. Correlation test was done using Spearman correlation test. RESULTS: A total of 40 COVID-19 patients were included in the analysis, with 50% having mild disease and other half having severe disease. The NLR, CRP, and D-dimer were significantly higher in severe COVID-19 group. Significant correlation was found between NLR and CRP (p = 0.001 and r = 0.506) and also with D-dimer level (p = 0.000 and r = 0.570) in differentiating severity of COVID-19. CONCLUSION: NLR is correlated with CRP and D-dimer level; therefore, NLR may serve as reliable, cost-effective, and practical inflammatory biomarker for differentiating severe and non-severe COVID-19 cases.

SARS-CoV-2-Specific Immune Response and the Pathogenesis of COVID-19

The review aims to consolidate research findings on the molecular mechanisms and virulence and pathogenicity characteristics of coronavirus disease (COVID-19) causative agent, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and their relevance to four typical stages in the development of acute viral infection. These four stages are invasion; primary blockade of antiviral innate immunity; engagement of the virus's protection mechanisms against the factors of adaptive immunity; and acute, long-term complications of COVID-19. The invasion stage entails the recognition of the spike protein (S) of SARS-CoV-2 target cell receptors, namely, the main receptor (angiotensin-converting enzyme 2, ACE2), its coreceptors, and potential alternative receptors. The presence of a diverse repertoire of receptors allows SARS-CoV-2 to infect various types of cells, including those not expressing ACE2. During the second stage, the majority of the polyfunctional structural, non-structural, and extra proteins SARS-CoV-2 synthesizes in infected cells are involved in the primary blockage of antiviral innate immunity. A high degree of redundancy and systemic action characterizing these pathogenic factors allows SARS-CoV-2 to overcome antiviral mechanisms at the initial stages of invasion. The third stage includes passive and active protection of the virus from factors of adaptive immunity, overcoming of the barrier function at the focus of inflammation, and generalization of SARS-CoV-2 in the body. The fourth stage is associated with the deployment of variants of acute and long-term complications of COVID-19. SARS-CoV-2's ability to induce autoimmune and autoinflammatory pathways of tissue invasion and development of both immunosuppressive and hyperergic mechanisms of systemic inflammation is critical at this stage of infection.

Low Levels of Granulocytic Myeloid-Derived Suppressor Cells May Be a Good Marker of Survival in the Follow-Up of Patients With Severe COVID-19

Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes a disease (coronavirus disease 2019, COVID-19) that may develop into a systemic disease with immunosuppression and death in its severe form. Myeloid-derived suppressive cells (MDSCs) are inhibitory cells that contribute to immunosuppression in patients with cancer and infection. Increased levels of MDSCs have been found in COVID-19 patients, although their role in the pathogenesis of severe COVID-19 has not been clarified. For this reason, we raised the question whether MDSCs could be useful in the follow-up of patients with severe COVID-19 in the intensive care unit (ICU). Thus, we monitored the immunological cells, including MDSCs, in 80 patients admitted into the ICU. After 1, 2, and 3 weeks, we examined for a possible association with mortality (40 patients). Although the basal levels of circulating MDSCs did not discriminate between the two groups of patients, the last measurement before the endpoint (death or ICU discharge) showed that patients discharged alive from the ICU had lower levels of granulocytic MDSCs (G-MDSCs), higher levels of activated lymphocytes, and lower levels of exhausted lymphocytes compared with patients who had a bad evolution (death). In conclusion, a steady increase of G-MDSCs during the follow-up of patients with severe COVID-19 was found in those who eventually died.

The Independent Association of TSH and Free Triiodothyronine Levels With Lymphocyte Counts Among COVID-19 Patients

Background

Both lymphopenia and thyroid dysfunction are commonly observed among COVID-19 patients. Whether thyroid function independently correlates with lymphocyte counts (LYM) remains to be elucidated.

Methods

We included consecutive adults without known thyroid disorder admitted to Queen Mary Hospital for COVID-19 from July 2020 to April 2021 who had thyroid-stimulating hormone (TSH), free thyroxine (fT4), free triiodothyronine (fT3) and LYM measured on admission.

Results

A total of 541 patients were included. Median LYM was 1.22 x 109/L, with 36.0% of the cohort lymphopenic. 83 patients (15.4%) had abnormal thyroid function tests (TFTs), mostly non-thyroidal illness syndrome (NTIS). Patients with lymphopenia had lower TSH, fT4 and fT3 levels than those without. Multivariable stepwise linear regression analysis revealed that both TSH (standardized beta 0.160, p<0.001) and fT3 (standardized beta 0.094, p=0.023), but not fT4, remained independently correlated with LYM, in addition to age, SARS-CoV-2 viral load, C-reactive protein levels, coagulation profile, sodium levels and more severe clinical presentations. Among the 40 patients who had reassessment of TFTs and LYM after discharge, at a median of 9 days from admission, there were significant increases in TSH (p=0.031), fT3 (p<0.001) and LYM (p<0.001). Furthermore, patients who had both lymphopenia and NTIS were more likely to deteriorate compared to those who only had either one alone, and those without lymphopenia or NTIS (p for trend <0.001).

Conclusion

TSH and fT3 levels showed independent positive correlations with LYM among COVID-19 patients, supporting the interaction between the hypothalamic-pituitary-thyroid axis and immune system in COVID-19.