The role of CD8+ regulatory T cells and B cell subsets in patients with COVID-19.

BACKGROUND: Coronavirus disease 2019 (COVID-19) has a wide clinical spectrum from asymptomatic to mild, moderate, and severe cases. There are still many unknowns about the role of immunoregulatory mechanisms in COVID-19. We aimed to study regulatory T cells (Tregs) and B cell subsets and evaluate their correlations with severity of COVID-19. METHODS: In total, 50 patients with COVID-19 confirmed by PCR (mean age = 49.9 ± 12.8 years) and 40 healthy control (mean age = 47.9 ± 14.7 years) were included in this study. The patients were classified as 14 mild (median age = 35.5 [24-73] years), 22 moderate (median age = 51.5 [28-67] years) and 14 severe (median age = 55.5 [42-67] years). Within 24 h of admission, flow cytometry was used to assess the lymphocyte subsets, Tregs and Bregs without receiving any relevant medication. RESULTS: In all patients with COVID-19, the proportion of CD3+CD8+ T cells was reduced (p = 0.004) and the CD8+ Tregs were increased compared with control (p = 0.001). While the levels of regulatory B cells, plasmablasts, and mature naive B cells were found to be significantly high, primarily memory B-cell levels were low in all patients compared with controls (p < 0.05). Total CD3+ T cells were negatively correlated with the length of stay in the hospital (r = -0.286, p = 0.044). DISCUSSION: The changes in T and B cell subsets may show the dysregulation in the immunity of patients with COVID-19. In this context, the association between CD8+ Tregs and COVID-19 severity may help clinicians to predict severe and fatal COVID-19 in hospitalized patients.

Correlation of myeloid-derived suppressor cells with C-reactive protein, ferritin and lactate dehydrogenase levels in patients with severe COVID-19.

The novel coronavirus disease 2019 (COVID-19) remains a global health emergency, and understanding the interactions between the virus and host immune responses is crucial to preventing its lethal effects. The expansion of myeloid-derived suppressor cells (MDSCs) in COVID-19, thereby suppressing immune responses, has been described as responsible for the severity of the disease, but the correlation between MDSC subsets and COVID-19 severity remains elusive. Therefore, we classified patients according to clinical and laboratory findings-aiming to investigate the relationship between MDSC subsets and laboratory findings such as high C-reactive protein, ferritin and lactate dehydrogenase levels, which indicate the severity of the disease. Forty-one patients with COVID-19 (26 mild and 15 severe; mean age of 49.7 ± 15 years) and 26 healthy controls were included in this study. MDSCs were grouped into two major subsets-polymorphonuclear MDSCs (PMN-MDSCs) and monocytic MDSCs-by flow cytometric immunophenotyping, and PMN-MDSCs were defined as mature and immature, according to CD16 expressions, for the first time in COVID-19. Total MDSCs, PMN-MDSCs, mature PMN-MDSCs and monocytic MDSCs were significantly higher in patients with COVID-19 compared with the healthy controls (P < .05). Only PMN-MDSCs and their immature PMN-MDSC subsets were higher in the severe subgroup than in the mild subgroup. In addition, a significant correlation was found between C-reactive protein, ferritin and lactate dehydrogenase levels and MDSCs in patients with COVID-19. These findings suggest that MDSCs play a role in the pathogenesis of COVID-19, while PMN-MDSCs, especially immature PMN-MDSCs, are associated with the severity of the disease.

Evaluation of P-wave dispersion in patients with newly diagnosed coronavirus disease 2019.

AIM: The aim of the current study was to evaluate P-wave dispersion (PWD) as a predictor of atrial fibrillation in patients with newly diagnosed COVID-19. In addition, the relationship between the PWD and inflammation parameters was investigated. METHODS: A total of 140 newly diagnosed COVID-19 patients and 140 age- and sex-matched healthy individuals were included in the study. The risk of atrial fibrillation was evaluated by calculating the electrocardiographic PWD. C-reactive protein (CRP), white blood cell, neutrophil and neutrophil-to-lymphocyte ratio (NLR) were measured in patients with newly diagnosed COVID-19. RESULTS: PWD, white blood cell, NLR and CRP levels were significantly higher in the COVID-19 group than the control group. There was a significant positive correlation between PWD and CRP level (rs = 0.510, P < 0.001) and NLR in COVID-19 group (rs = 0.302, P = 0.001). In their follow-up, 13 (9.3%) patients, 11 of whom were in the ICU, developed new atrial fibrillation. CONCLUSION: Our study showed for the first time in literature that the PWD, evaluated electrocardiographically in patients with newly diagnosed COVID-19, was prolonged compared with normal healthy individuals. A positive correlation was found between PWD, CRP level and NLR. We believe that pretreatment evaluation of PWD in patients with newly diagnosed COVID-19 would be beneficial for predicting atrial fibrillation risk.

[Evaluation of Patients Diagnosed with COVID-19 in Terms of Risk Factors]. / COVID-19 Tanili Hastalarin Risk Faktörleri Açisindan Degerlendirilmesi.

Coronaviruses are RNA viruses that can cause disease in the upper and lower respiratory tract in humans and animals. Lately, a new coronavirus causing pneumonia cases was detected in Wuhan, China in December 2019. Soon after, the name of the virus was identified as the "severe acute respiratory syndrome coronavirus-2", and the World Health Organization named the disease coronavirus disease-2019 (COVID-19). In our country, the first cases began to appear in the second week of March. In this study, we aimed to investigate the demographic characteristics and risk factors of patients with the diagnosis of COVID-19. A total of 100 patients (53 female and 47 male) were included in our study. The patients included in the study were randomly selected from the registration system and their information was evaluated retrospectively. The mean age of the patients was 54.42 (Age range= 20-90). When the risk factors for catching the disease were evaluated; it was determined that there was at least one risk factor in 46 patients; 30 patients had close contact with the COVID-19 patient in the social environment (30%) and 16 patients had a travel history outside the city in the last 14 days (16%). The most common symptoms in our patients were; cough (93%), fever (42%), dyspnea (22%), weakness (8%), sore throat (7%), diarrhea (6%), headache (5%) and sputum (2%). The most common comorbid conditions in our patients were detected as hypertension (42%), diabetes mellitus (DM) (21%), congestive heart failure (10%), allergic asthma (7%), chronic obstructive pulmonary disease (6%), rheumatoid arthritis (3%), coronary artery disease (2%), solid organ tumour (2%), depression (1%) and epilepsy (1%). The mean age of our 15 patients who were monitored in intensive care unit was 65 y (± 11.46), the mean age of 85 patients followed in the service was 52.55 (± 16.35) and this difference was statistically significant (p= 0.006). When these two groups were compared in terms of comorbid diseases, the presence of DM was 40% higher (n= 6) in intensive care patients, and this difference was statistically significant (p= 0.05). In addition, the majority [11 patients (73%)] of the patients hospitalized in the intensive care unit were male (p= 0.03). When smoking was evaluated as a risk factor for serious illness, 4 of 11 patients (26%) in intensive care unit had a smoking history, while none of the patients who have died due to COVID-19 had a smoking history. These findings suggested to us that smoking does not increase the severity of COVID-19 disease. As a result, knowledge about the disease should be increased rapidly by sharing the studies on risk factors, transmission routes and clinical features of COVID-19 infection, which affects the whole world.

Impact of low molecular weight heparin administration on the clinical course of the COVID-19 disease

Background: Lymphopenia is the most important criterion of mortality and discharging feature for patients infected with coronavirus disease 2019 (COVID-19). This study aimed to investigate the clinical impact of a low molecular weight heparin (LMWH) treatment on the clinical course of COVID-19. Materials and methods: Patients' clinical symptoms, radiologic outcomes, hematologic, biochemical, D-dimer, and C-reactive protein (CRP) results were obtained from their medical records. Participants were separated into 2 groups: one was treated with LMWH and the other was not. Improvement in the patients was compared before and after treatment. Results: Ninety-six patients who were diagnosed with COVID-19 between April and May 2020 were retrospectively analyzed. The multivariable analysis showed that the count of lymphocytes, D-dimer, and CRP levels were significantly improved in the LMWH group, as compared to the control group (OR, (95% CI) 0.628 (0.248­0.965), P < 0.001); OR, (95% CI) 0.356 (0.089­0.674), P < 0.001, respectively). The area under the receiver operating characteristic (ROC) curve analysis was AUC: 0.679 ± 0.055, 0.615 ± 0.058, and 0.633 ± 0.057, respectively; the ß-value was found to be ­1.032, ­0.026, and ­0.465, respectively. Conclusion: The LMWH treatment group demonstrated better laboratory findings, including recovery in the lymphocyte count, CRP, and D-dimer results.

Evaluation of electrocardiographic ventricular repolarization variables in patients with newly diagnosed COVID-19.

INTRODUCTION: Coronavirus disease 2019 (COVID-19) is a newly recognized infectious disease that has spread rapidly. COVID-19 has been associated with a number of cardiovascular complications, including arrhythmias. The mechanism of ventricular arrhythmias in patients with COVID-19 is uncertain. The aim of the present study was to evaluate the ventricular repolarization by using the Tp-e interval, QT dispersion, Tp-e/QT ratio, and Tp-e/QTc ratio as candidate markers of ventricular arrhythmias in patients with newly diagnosed COVID-19. In addition, the relationship between the repolarization parameters and the CRP (C-reactive protein) was investigated. METHODS: 75 newly diagnosed COVID-19 patients, 75 age and sex matched healthy subjects were included in the study between 20th March 2020 and 10th April 2020. The risk of ventricular arrhythmias was evaluated by calculating the electrocardiographic Tp-e and QT interval, Tp-e dispersion, corrected QT(QTc), QT dispersion (QTd), corrected QTd, Tp-e/QT and Tp-e/QTc ratios. CRP values were also measured in patients with newly diagnosed COVID-19. RESULTS: Tp-e interval (80.7 ±â€¯4.6 vs. 70.9 ±â€¯4.8; p < .001), Tp-e / QT ratio (0.21 ±â€¯0.01 vs. 0.19 ±â€¯0.01; p < .001) and Tp-e/QTc ratio (0.19 ±â€¯0.01 vs.0.17 ±â€¯0.01; p < .001) were significantly higher in patients with newly diagnosed COVID-19 than the control group. There was a significant positive correlation between Tp-e interval, Tp-e/QTc ratio and CRP in patients with newly diagnosed COVID-19 (rs = 0.332, p = .005, rs = 0.397, p < .001 consecutively). During their treatment with hydroxychloroquine (HCQ), azithromycin and favipiravir, ventricular tachycardia episodes were observed in in two COVID-19 patients during their hospitalization in the intensive care unit. CONCLUSION: Our study showed for the first time in literature that the Tp-e interval, Tp-e/QT ratio, and Tp-e/QTc ratio, which are evaluated electrocardiographically in patients with newly diagnosed COVID-19, were prolonged compared with normal healthy individuals. A positive correlation was determined between repolarization parameters and CRP. We believe that pre-treatment evaluation of repolarization parameters in newly diagnosed COVID-19 would be beneficial for predicting ventricular arrhythmia risk.