RESUMO
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a known virus that leads to a respiratory disease called coronavirus disease 19 (COVID-19). Natural killer (NK) cells, as members of innate immunity, possess crucial roles in restricting viral infections, including COVID-19. Their functions and development depend on receiving signals through various receptors, of which killer cell immunoglobulin-like receptors (KIRs) belong to the most effective ones. Different studies investigated the association between KIR gene content and susceptibility to COVID-19. Since previous studies have yielded contradictory results, we designed this meta-analysis study to draw comprehensive conclusions about COVID-19 risk and KIR gene association. According to PRISMA guidelines, a systematic search was performed in the electronic databases to find all studies investigating KIR gene contents in COVID-19 patients before March 2023. Any association between KIR genes and COVID-19 risk was determined by calculating pooled odds ratio (OR) and 95% confidence interval (CI). After applying the inclusion and exclusion criteria, 1673 COVID-19 patients and 1526 healthy controls from eight studies were included in this meta-analysis. As the main results, we observed a positive association between the 2DL3 (OR = 1.48, 95% CI = 1.17-1.88, P < 0.001) and susceptibility to COVID-19 and a negative association between the 2DP1 and the risk for COVID-19 (OR = 0.48, 95% CI = 0.23-0.99, P = 0.049). This meta-analysis demonstrated that KIR2DL3, as a member of iKIRs, might be associated with an increased risk of COVID-19 disease.
RESUMO
Background: Buerger's disease, also known as Thromboangiitis Obliterans (TAO), is a progressive, inflammatory vascular disease with unknown etiology. Objective: To address the degree of T cell immunosenescence in this inflammatory disease, the frequency of senescent T cells expressing CD57 and/or CD153 (CD30L) in patients with TAO. Methods: In this study, nine male cigarette smoker patients with TAO, nine male healthy cigarette smokers, and nine male healthy non-smoker blood donors were enrolled. PBMCs were extracted from the blood of all participants and stored in liquid nitrogen before use. The percentages of senescent T cells were detected by flow cytometry. The results were analyzed using non-parametric statistical tests. Results: The frequencies of senescent CD3+CD4+CD57+CD153+ and CD3+CD4+CD57-CD153+ T cells significantly increased in patients compared with the non-smoker controls (p=0.01 and p=0.04, respectively). The frequency of senescent CD3+CD4-CD57-CD153+ T cells was higher in patients compared with the smoker controls (p=0.02). In patients with TAO, CD57+CD153- cells were more frequent in CD3hiCD4- and CD3hiCD4+ T cells compared with the CD3loCD4- and CD3loCD4+ T cells (p=0.008 and p=0.0002, respectively). Conversely, the frequency of CD57-CD153+ T cells was significantly higher in CD3loCD4- T cells compared with the CD3hiCD4- T cells (p=0.004). The percentage of CD3+CD4+CD57+CD153- T cells correlated negatively with smoking level in smoker controls (p=0.02, Spearman r=-0.80). Conclusion: Elevated frequencies of senescent CD4+CD57+CD153+ and CD4+CD57-CD153+ T cells in patients compared with non-smoker and smoker controls suggest the contribution of immunosenescence in TAO.
