Immunological evaluation of patients with 2019 novel coronavirus pneumonia: CD4+ and CD16+ cells may predict severity and prognosis.

PURPOSE: Available but insufficient evidence shows that changes may occur in the immune system following coronavirus disease 2019 (COVID-19). The present study aimed at evaluating immunological changes in patients with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pneumonia compared with the control group. METHOD: The present study was performed on 95 patients with COVID-19 (32 severe and 63 moderate cases) and 22 healthy controls. Relationship between immune cells, disease severity and lung involvement was assessed. Binary logistic regression and ROC curve tests were used for statistical analysis. RESULTS: A significant decrease was observed in CD20+ cell counts of the patients. To differentiate patients from healthy individuals, the cutoff point for the CD4+ cell count was 688 /µL, sensitivity 0.96, and specificity 0.84. An increase in CD4+ cells reduces the odds of severe disease (odds ratio = 0.82, P = 0.047) and death (odds ratio = 0.74, P = 0.029). CD4+ cells play a pivotal role in the severity of lung involvement (P = 0.03). In addition to CD4+ cells, Fc gamma receptor III (FcγRIII) (CD16) also played a significant prognosis (odds ratio = 0.55, P = 0.047). In severe cases, C-reactive protein, Blood urea nitrogen, and Creatine phosphokinase levels, as well as neutrophil counts, were significantly higher than those of moderate ones whereas lymphocyte count in severe cases was lower than that of moderate ones. CONCLUSION: The number of total T-cells and B-cells in patients with COVID-19 was lower than that of controls; however, their NK cells increased. FcγRIII and CD4+ cells are of great importance due to their association with COVID-19 prognosis.

Post-COVID-19 hematologic complications: a systematic review.

INTRODUCTION: COVID-19 crisis continues around the world. Some patients developed complications after the disease, which have been reported in limited studies. The aim of this study is to comprehensively assess the post-COVID hematologic complications in patients. AREAS COVERED: We searched PubMed, Scopus, and Google Scholar between January 2020 and August 2021 using related keywords. Evaluation of the article was performed by two independent researchers. The extracted data included the number of patients, age, type of hematological complication, duration of follow-up, response to treatment and prognosis. EXPERT OPINION: Sixty-five articles reported post-COVID hematologic complications. The most frequent hematologic complication in COVID-19 patients is thromboembolic events, which often occur in two forms: deep vein thrombosis (DVT) and pulmonary embolism (PE). In a group of patients after the diagnosis of COVID-19, a significant decrease in platelets was observed, which was attributed to the ITP induced by COVID-19. Hemolytic anemia and aplastic anemia have also been reported rarely in patients. Finally, post-COVID hematologic complications appear to go beyond thromboembolic events. Although these complications have rarely been reported, searching for methods to identify susceptible patients and prevent these complications could be the subject of future research.

Vitamin D Insufficiency in Disease Severity and Prognosis of the Patients with SARS Corona Virus-2 Infection Role of Vitamin D in COVID-19

The global crisis caused by the SARS Corona virus-2 infection is continuing through 2021, with more than 3.5 million deaths. Several risk factors for this virus’s severity and death were documented, including diabetes, hypertension, and ischemic heart disease. To evaluate the relation between serum vitamin D3 level, the disease severity, and prognosis of the patients with SARS Corona virus-2 infection. Patients with COVID-19 were evaluated for serum vitamin D levels and laboratory data. Correlation between vitamin D levels and laboratory data with disease severity and prognosis was assessed. Cox and logistic regression tests, as well as ROC curves, were used for data analysis. Ninety-eight patients with Corona virus-2 disease (COVID-19), which consisted of sixty patients with moderate COVID-19 in the general wards, and thirty-eight patients with severe COVID-19 in the intensive care unit (ICU), were evaluated. The mean age in the general wards was lower than in ICU (60.96±14.86 compared to 67.94±16.46, P=0.001), and the mean serum vitamin D level in the patients admitted in the general wards was higher than in the ICU (31 ng/mL compared to 20.57 ng/mL, P=0.003). Furthermore, vitamin D deficiency (25 (OH) D <25 ng/ml) significantly increased the risk of severe disease. (odds ratio=2.91, P=0.019) and mortality (odds ratio=3.64, P=0.026). Vitamin D deficiency is a risk factor for disease severity and poor prognosis in COVID-19. Vitamin D levels of 25 ng/mL can be used as a cut-off value for predicting severity and prognosis.

Regulatory T Cells in Immunopathogenesis and Severity of COVID-19: A Systematic Review.

BACKGROUND: Severe cases of coronavirus disease 2019 (COVID-19) often experience hyper-inflammatory reactions, acute respiratory distress syndrome (ARDS), blood clotting, and organ damage. The most prominent immunopathology of advanced COVID-19 is cytokine release syndrome, or "cytokine storm" which is attributed to a defect of immune-regulating mechanisms. This study aimed to evaluate the role of regulatory T cells (Tregs) as one of the main cells that maintain immune homeostasis. METHODS: A systematic search was performed on PubMed, Scopus and Google Scholar. All English articles related to Treg's role in COVID-19 were extracted and evaluated by two researchers independently. Study eligibility was assessed based on modified Evidence-based librarianship (EBL) checklist. RESULTS: Nineteen eligible studies comparing Treg cells in COVID-19 patients with the control group or comparing alterations of this cell in severe and moderate patients were evaluated. Currently, there is no consensus regarding the increase or decrease of Tregs in COVID-19 patients compared to the control group. However, it was observed that Tregs in severe COVID-19 patients were significantly lower than moderate patients, resulting in uncontrolled inflammation and cytokine storm. CONCLUSION: Regulatory T cells can be one of the determinants of disease severity and prognosis in patients with COVID-19 by inhibiting rampant inflammation and preventing cytokine storms.