COVID-19 Infection in Patients with Comorbidities: Clinical and Immunological Insight

Abstract

Aim Our study's objectives were to study the clinical and laboratory characteristics that may serve as biomarkers for predicting disease severity, IL-10 levels, and frequencies of different T cell subsets in comorbid COVID-19 patients. Methods Sixty-two hospitalized COVID-19 patients with comorbidities were assessed clinically and radiologically. Blood samples were collected to assess the T lymphocyte subsets by flow cytometry and IL-10 levels by ELISA. Results The most common comorbidities observed in COVID-19 patients were diabetes mellitus (DM), hypertension, and malignancies. Common symptoms and signs included fever, cough, dyspnea, fatigue, myalgia, and sore throat. CRP, ferritin, D dimer, LDH, urea, creatinine, and direct bilirubin were significantly increased in patients than controls. Lymphocyte count and CD4+ and CD8+ T-cells were significantly decreased in comorbid COVID-19 patients, and CD25 and CD45RA expression were increased. CD4+ and CD8+ regulatory T cells (Tregs) and IL-10 levels were significantly decreased in patients. Conclusions Many parameters were found to be predictive of severity in the comorbid patients in our study. Significant reductions in the levels and activation of CD4+ and CD8+ T-cells were found. In addition, CD4+ and CD8+ Tregs were significant decreased in patients, probably pointing to a prominent role of CD8+ Tregs in dampening CD4+ T-cell activation.

Incidence of diabetic ketoacidosis during COVID-19 pandemic: a meta-analysis of 124,597 children with diabetes

“…Announced by the World Health Organization in January 2020 as a global health emergency and in March 2020 as a pandemic, coronavirus disease 2019 (COVID-19) is a severe respiratory illness. 1 , 2 COVID-19 is highly infective, presenting with a range of symptoms; however, up to 80% of symptomatic COVID-19 infections feature only flu-like symptoms with no complications; 3 advanced complications such as renal or circulatory failure have been reported with severe cases or with other comorbidities or risk factors including old age, hypertension, cardiovascular diseases, or diabetes, especially type 1 diabetes mellitus (T1DM). 4 …”

T Cell Response to SARS-CoV-2 Coinfection and Comorbidities

“…As a result of these observations, Treg cells may potentially play a role in assisting with SARS-CoV-2 recovery. However, some conflicting studies reported that a reduction in Treg cells and lower expressions of FOXP3, TGF-β, and IL-10 were present in patients with severe SARS-CoV-2 infection [ 45 , 46 , 47 ]. Therefore, more research is required for the role of Treg cells.…”

“…Hypertension increases the T cell populations and inflammatory cytokine secretion of tumor necrosis factor TNFα, IFNγ, and IL-17A [ 100 , 101 ]. However, one study indicates that there was no difference in T cell populations between hypertensive patients and healthy people [ 47 ]. T cells in hypertensive patients displayed senescence phenotypes with lowered co-expression of CD27 and CD28, resulting in difficulty protecting against viral infections [ 102 ].…”

Immune Checkpoints Receptors Expression of Macrophage/Monocytes in Response to Acute Viral Respiratory Infection

“…In healthy individuals, the innate immune system serves as the initial defense against most infectious signals. It achieves this by orchestrating a protective inflammatory response that evolves through various stages, starting from initiation and full-blown inflammation to resolution and the restoration of tissue integrity [1]. Within the fully active immune system, macrophages, which originate from monocytes, act as phagocytic cells.…”